[PATCH v7 0/7] Add Nuvoton NCT6694 MFD drivers

[PATCH v7 0/7] Add Nuvoton NCT6694 MFD drivers

[Ming Yu]

This patch series introduces support for Nuvoton NCT6694, a peripheral
expander based on USB interface. It models the chip as an MFD driver
(1/7), GPIO driver(2/7), I2C Adapter driver(3/7), CANfd driver(4/7),
WDT driver(5/7), HWMON driver(6/7), and RTC driver(7/7).

The MFD driver implements USB device functionality to issue
custom-define USB bulk pipe packets for NCT6694. Each child device can
use the USB functions nct6694_read_msg() and nct6694_write_msg() to issue
a command. They can also request interrupt that will be called when the
USB device receives its interrupt pipe.

The following introduces the custom-define USB transactions:
        nct6694_read_msg - Send bulk-out pipe to write request packet
                           Receive bulk-in pipe to read response packet
                           Receive bulk-in pipe to read data packet

        nct6694_write_msg - Send bulk-out pipe to write request packet
                            Send bulk-out pipe to write data packet
                            Receive bulk-in pipe to read response packet
                            Receive bulk-in pipe to read data packet

Changes since version 6:
- Fix nct6694_can_handle_state_change() in nct6694_canfd.c
- Fix warnings in nct6694_canfd.c
- Move the nct6694_can_priv's bec to the end in nct6694_canfd.c
- Fix warning in nct6694_wdt.c
- Fix temp_hyst's data type to signed variable in nct6694-hwmon.c

Changes since version 5:
- Modify the module name and the driver name consistently
- Fix mfd_cell to MFD_CELL_NAME() and MFD_CELL_BASIC()
- Drop unnecessary macros in nct6694.c
- Update private data and drop mutex in nct6694_canfd.c
- Fix nct6694_can_handle_state_change() in nct6694_canfd.c

Changes since version 4:
- Modify arguments in read/write function to a pointer to cmd_header
- Modify all callers that call the read/write function
- Move the nct6694_canfd.c to drivers/net/can/usb/
- Fix the missing rx offload function in nct6694_canfd.c
- Fix warngings in nct6694-hwmon.c

Changes since version 3:
- Modify array buffer to structure for each drivers
- Fix defines and comments for each drivers
- Add header <linux/bits.h> and use BIT macro in nct6694.c and
  gpio-nct6694.c
- Modify mutex_init() to devm_mutex_init()
- Add rx-offload helper in nct6694_canfd.c
- Drop watchdog_init_timeout() in nct6694_wdt.c
- Modify the division method to DIV_ROUND_CLOSEST() in nct6694-hwmon.c
- Drop private mutex and use rtc core lock in rtc-nct6694.c
- Modify device_set_wakeup_capable() to device_init_wakeup() in
  rtc-nct6694.c

Changes since version 2:
- Add MODULE_ALIAS() for each child driver
- Modify gpio line names be a local variable in gpio-nct6694.c
- Drop unnecessary platform_get_drvdata() in gpio-nct6694.c
- Rename each command in nct6694_canfd.c
- Modify each function name consistently in nct6694_canfd.c
- Modify the pretimeout validation procedure in nct6694_wdt.c
- Fix warnings in nct6694-hwmon.c

Changes since version 1:
- Implement IRQ domain to handle IRQ demux in nct6694.c
- Modify USB_DEVICE to USB_DEVICE_AND_INTERFACE_INFO API in nct6694.c
- Add each driver's command structure
- Fix USB functions in nct6694.c
- Fix platform driver registration in each child driver
- Sort each driver's header files alphabetically
- Drop unnecessary header in gpio-nct6694.c
- Add gpio line names in gpio-nct6694.c
- Fix errors and warnings in nct6694_canfd.c
- Fix TX-flow control in nct6694_canfd.c
- Fix warnings in nct6694_wdt.c
- Drop unnecessary logs in nct6694_wdt.c
- Modify start() function to setup device in nct6694_wdt.c
- Add voltage sensors functionality in nct6694-hwmon.c
- Add temperature sensors functionality in nct6694-hwmon.c
- Fix overwrite error return values in nct6694-hwmon.c
- Add write value limitation for each write() function in nct6694-hwmon.c
- Drop unnecessary logs in rtc-nct6694.c
- Fix overwrite error return values in rtc-nct6694.c
- Modify to use dev_err_probe API in rtc-nct6694.c


Ming Yu (7):
  mfd: Add core driver for Nuvoton NCT6694
  gpio: Add Nuvoton NCT6694 GPIO support
  i2c: Add Nuvoton NCT6694 I2C support
  can: Add Nuvoton NCT6694 CANFD support
  watchdog: Add Nuvoton NCT6694 WDT support
  hwmon: Add Nuvoton NCT6694 HWMON support
  rtc: Add Nuvoton NCT6694 RTC support

 MAINTAINERS                         |  13 +
 drivers/gpio/Kconfig                |  12 +
 drivers/gpio/Makefile               |   1 +
 drivers/gpio/gpio-nct6694.c         | 458 ++++++++++++++
 drivers/hwmon/Kconfig               |  10 +
 drivers/hwmon/Makefile              |   1 +
 drivers/hwmon/nct6694-hwmon.c       | 947 ++++++++++++++++++++++++++++
 drivers/i2c/busses/Kconfig          |  10 +
 drivers/i2c/busses/Makefile         |   1 +
 drivers/i2c/busses/i2c-nct6694.c    | 152 +++++
 drivers/mfd/Kconfig                 |  18 +
 drivers/mfd/Makefile                |   2 +
 drivers/mfd/nct6694.c               | 373 +++++++++++
 drivers/net/can/usb/Kconfig         |  11 +
 drivers/net/can/usb/Makefile        |   1 +
 drivers/net/can/usb/nct6694_canfd.c | 809 ++++++++++++++++++++++++
 drivers/rtc/Kconfig                 |  10 +
 drivers/rtc/Makefile                |   1 +
 drivers/rtc/rtc-nct6694.c           | 286 +++++++++
 drivers/watchdog/Kconfig            |  11 +
 drivers/watchdog/Makefile           |   1 +
 drivers/watchdog/nct6694_wdt.c      | 295 +++++++++
 include/linux/mfd/nct6694.h         | 102 +++
 23 files changed, 3525 insertions(+)
 create mode 100644 drivers/gpio/gpio-nct6694.c
 create mode 100644 drivers/hwmon/nct6694-hwmon.c
 create mode 100644 drivers/i2c/busses/i2c-nct6694.c
 create mode 100644 drivers/mfd/nct6694.c
 create mode 100644 drivers/net/can/usb/nct6694_canfd.c
 create mode 100644 drivers/rtc/rtc-nct6694.c
 create mode 100644 drivers/watchdog/nct6694_wdt.c
 create mode 100644 include/linux/mfd/nct6694.h

-- 
2.34.1

[PATCH v7 1/7] mfd: Add core driver for Nuvoton NCT6694

[Ming Yu]

The Nuvoton NCT6694 is a peripheral expander with 16 GPIO chips,
6 I2C controllers, 2 CANfd controllers, 2 Watchdog timers, ADC,
PWM, and RTC.

This driver implements USB device functionality and shares the
chip's peripherals as a child device.

Each child device can use the USB functions nct6694_read_msg()
and nct6694_write_msg() to issue a command. They can also request
interrupt that will be called when the USB device receives its
interrupt pipe.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
 MAINTAINERS                 |   7 +
 drivers/mfd/Kconfig         |  18 ++
 drivers/mfd/Makefile        |   2 +
 drivers/mfd/nct6694.c       | 373 ++++++++++++++++++++++++++++++++++++
 include/linux/mfd/nct6694.h | 102 ++++++++++
 5 files changed, 502 insertions(+)
 create mode 100644 drivers/mfd/nct6694.c
 create mode 100644 include/linux/mfd/nct6694.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 873aa2cce4d7..c700a0b96960 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16918,6 +16918,13 @@ F:	drivers/nubus/
 F:	include/linux/nubus.h
 F:	include/uapi/linux/nubus.h
 
+NUVOTON NCT6694 MFD DRIVER
+M:	Ming Yu <tmyu0@nuvoton.com>
+L:	linux-kernel@vger.kernel.org
+S:	Supported
+F:	drivers/mfd/nct6694.c
+F:	include/linux/mfd/nct6694.h
+
 NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
 M:	Antonino Daplas <adaplas@gmail.com>
 L:	linux-fbdev@vger.kernel.org
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 6b0682af6e32..c97a2bdcea0b 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1045,6 +1045,24 @@ config MFD_MENF21BMC
 	  This driver can also be built as a module. If so the module
 	  will be called menf21bmc.
 
+config MFD_NCT6694
+	tristate "Nuvoton NCT6694 support"
+	select MFD_CORE
+	depends on USB
+	help
+	  This enables support for the Nuvoton USB device NCT6694, which shares
+	  peripherals.
+
+	  This driver provides core APIs to access the NCT6694 hardware
+	  monitoring and control features.
+
+	  The NCT6694 is a versatile multi-function device that supports
+	  functionalities such as GPIO, I2C, CAN, WDT, HWMON, and RTC
+	  management.
+
+	  Additional drivers must be enabled to utilize the specific
+	  functionalities of the device.
+
 config MFD_OCELOT
 	tristate "Microsemi Ocelot External Control Support"
 	depends on SPI_MASTER
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 9220eaf7cf12..7725b732e265 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -121,6 +121,8 @@ obj-$(CONFIG_MFD_MC13XXX)	+= mc13xxx-core.o
 obj-$(CONFIG_MFD_MC13XXX_SPI)	+= mc13xxx-spi.o
 obj-$(CONFIG_MFD_MC13XXX_I2C)	+= mc13xxx-i2c.o
 
+obj-$(CONFIG_MFD_NCT6694)	+= nct6694.o
+
 obj-$(CONFIG_MFD_CORE)		+= mfd-core.o
 
 ocelot-soc-objs			:= ocelot-core.o ocelot-spi.o
diff --git a/drivers/mfd/nct6694.c b/drivers/mfd/nct6694.c
new file mode 100644
index 000000000000..ab857d5b06a5
--- /dev/null
+++ b/drivers/mfd/nct6694.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 core driver using USB interface to provide
+ * access to the NCT6694 hardware monitoring and control features.
+ *
+ * The NCT6694 is a versatile multi-function device that supports
+ * functionalities such as GPIO, I2C, CAN, WDT, HWMON and RTC
+ * management.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/bits.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+static const struct mfd_cell nct6694_dev[] = {
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x0),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x1),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x2),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x3),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x4),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x5),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x6),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x7),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x8),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0x9),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xA),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xB),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xC),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xD),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xE),
+	MFD_CELL_BASIC("gpio-nct6694", NULL, NULL, 0, 0xF),
+
+	MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x0),
+	MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x1),
+	MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x2),
+	MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x3),
+	MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x4),
+	MFD_CELL_BASIC("i2c-nct6694", NULL, NULL, 0, 0x5),
+
+	MFD_CELL_BASIC("nct6694_canfd", NULL, NULL, 0, 0x0),
+	MFD_CELL_BASIC("nct6694_canfd", NULL, NULL, 0, 0x1),
+
+	MFD_CELL_BASIC("nct6694_wdt", NULL, NULL, 0, 0x0),
+	MFD_CELL_BASIC("nct6694_wdt", NULL, NULL, 0, 0x1),
+
+	MFD_CELL_NAME("nct6694-hwmon"),
+	MFD_CELL_NAME("rtc-nct6694"),
+};
+
+static int nct6694_response_err_handling(struct nct6694 *nct6694,
+					 unsigned char err_status)
+{
+	switch (err_status) {
+	case NCT6694_NO_ERROR:
+		return err_status;
+	case NCT6694_NOT_SUPPORT_ERROR:
+		dev_warn(nct6694->dev, "Command is not supported!\n");
+		break;
+	case NCT6694_NO_RESPONSE_ERROR:
+		dev_warn(nct6694->dev, "Command received no response!\n");
+		break;
+	case NCT6694_TIMEOUT_ERROR:
+		dev_warn(nct6694->dev, "Command timed out!\n");
+		break;
+	case NCT6694_PENDING:
+		dev_warn(nct6694->dev, "Command is pending!\n");
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return -EIO;
+}
+
+int nct6694_read_msg(struct nct6694 *nct6694, const struct nct6694_cmd_header *cmd_hd, void *buf)
+{
+	union nct6694_usb_msg *msg = nct6694->usb_msg;
+	int tx_len, rx_len, ret;
+
+	guard(mutex)(&nct6694->access_lock);
+
+	/* Send command packet to USB device */
+	memcpy(&msg->cmd_header, cmd_hd, sizeof(*cmd_hd));
+	msg->cmd_header.hctrl = NCT6694_HCTRL_GET;
+
+	ret = usb_bulk_msg(nct6694->udev,
+			   usb_sndbulkpipe(nct6694->udev, NCT6694_BULK_OUT_EP),
+			   &msg->cmd_header, sizeof(*msg), &tx_len,
+			   nct6694->timeout);
+	if (ret)
+		return ret;
+
+	/* Receive response packet from USB device */
+	ret = usb_bulk_msg(nct6694->udev,
+			   usb_rcvbulkpipe(nct6694->udev, NCT6694_BULK_IN_EP),
+			   &msg->response_header, sizeof(*msg), &rx_len,
+			   nct6694->timeout);
+	if (ret)
+		return ret;
+
+	/* Receive data packet from USB device */
+	ret = usb_bulk_msg(nct6694->udev,
+			   usb_rcvbulkpipe(nct6694->udev, NCT6694_BULK_IN_EP),
+			   buf, le16_to_cpu(cmd_hd->len), &rx_len,
+			   nct6694->timeout);
+	if (ret)
+		return ret;
+
+	if (rx_len != le16_to_cpu(cmd_hd->len)) {
+		dev_err(nct6694->dev, "Expected received length %d, but got %d\n",
+			le16_to_cpu(cmd_hd->len), rx_len);
+		return -EIO;
+	}
+
+	return nct6694_response_err_handling(nct6694, msg->response_header.sts);
+}
+EXPORT_SYMBOL(nct6694_read_msg);
+
+int nct6694_write_msg(struct nct6694 *nct6694, const struct nct6694_cmd_header *cmd_hd, void *buf)
+{
+	union nct6694_usb_msg *msg = nct6694->usb_msg;
+	int tx_len, rx_len, ret;
+
+	guard(mutex)(&nct6694->access_lock);
+
+	/* Send command packet to USB device */
+	memcpy(&msg->cmd_header, cmd_hd, sizeof(*cmd_hd));
+	msg->cmd_header.hctrl = NCT6694_HCTRL_SET;
+
+	ret = usb_bulk_msg(nct6694->udev,
+			   usb_sndbulkpipe(nct6694->udev, NCT6694_BULK_OUT_EP),
+			   &msg->cmd_header, sizeof(*msg), &tx_len,
+			   nct6694->timeout);
+	if (ret)
+		return ret;
+
+	/* Send data packet to USB device */
+	ret = usb_bulk_msg(nct6694->udev,
+			   usb_sndbulkpipe(nct6694->udev, NCT6694_BULK_OUT_EP),
+			   buf, le16_to_cpu(cmd_hd->len), &tx_len,
+			   nct6694->timeout);
+	if (ret)
+		return ret;
+
+	/* Receive response packet from USB device */
+	ret = usb_bulk_msg(nct6694->udev,
+			   usb_rcvbulkpipe(nct6694->udev, NCT6694_BULK_IN_EP),
+			   &msg->response_header, sizeof(*msg), &rx_len,
+			   nct6694->timeout);
+	if (ret)
+		return ret;
+
+	/* Receive data packet from USB device */
+	ret = usb_bulk_msg(nct6694->udev,
+			   usb_rcvbulkpipe(nct6694->udev, NCT6694_BULK_IN_EP),
+			   buf, le16_to_cpu(cmd_hd->len), &rx_len,
+			   nct6694->timeout);
+	if (ret)
+		return ret;
+
+	if (rx_len != le16_to_cpu(cmd_hd->len)) {
+		dev_err(nct6694->dev, "Expected transmitted length %d, but got %d\n",
+			le16_to_cpu(cmd_hd->len), rx_len);
+		return -EIO;
+	}
+
+	return nct6694_response_err_handling(nct6694, msg->response_header.sts);
+}
+EXPORT_SYMBOL(nct6694_write_msg);
+
+static void usb_int_callback(struct urb *urb)
+{
+	struct nct6694 *nct6694 = urb->context;
+	unsigned int *int_status = urb->transfer_buffer;
+	int ret;
+
+	switch (urb->status) {
+	case 0:
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		return;
+	default:
+		goto resubmit;
+	}
+
+	while (*int_status) {
+		int irq = __ffs(*int_status);
+
+		generic_handle_irq_safe(irq_find_mapping(nct6694->domain, irq));
+		*int_status &= ~BIT(irq);
+	}
+
+resubmit:
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret)
+		dev_dbg(nct6694->dev, "%s: Failed to resubmit urb, status %pe",
+			__func__, ERR_PTR(ret));
+}
+
+static void nct6694_irq_lock(struct irq_data *data)
+{
+	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
+
+	mutex_lock(&nct6694->irq_lock);
+}
+
+static void nct6694_irq_sync_unlock(struct irq_data *data)
+{
+	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
+
+	mutex_unlock(&nct6694->irq_lock);
+}
+
+static void nct6694_irq_enable(struct irq_data *data)
+{
+	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
+	irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+	nct6694->irq_enable |= BIT(hwirq);
+}
+
+static void nct6694_irq_disable(struct irq_data *data)
+{
+	struct nct6694 *nct6694 = irq_data_get_irq_chip_data(data);
+	irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+	nct6694->irq_enable &= ~BIT(hwirq);
+}
+
+static struct irq_chip nct6694_irq_chip = {
+	.name = "nct6694-irq",
+	.flags = IRQCHIP_SKIP_SET_WAKE,
+	.irq_bus_lock = nct6694_irq_lock,
+	.irq_bus_sync_unlock = nct6694_irq_sync_unlock,
+	.irq_enable = nct6694_irq_enable,
+	.irq_disable = nct6694_irq_disable,
+};
+
+static int nct6694_irq_domain_map(struct irq_domain *d, unsigned int irq,
+				  irq_hw_number_t hw)
+{
+	struct nct6694 *nct6694 = d->host_data;
+
+	irq_set_chip_data(irq, nct6694);
+	irq_set_chip_and_handler(irq, &nct6694_irq_chip, handle_simple_irq);
+
+	return 0;
+}
+
+static void nct6694_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
+{
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+}
+
+static const struct irq_domain_ops nct6694_irq_domain_ops = {
+	.map	= nct6694_irq_domain_map,
+	.unmap	= nct6694_irq_domain_unmap,
+};
+
+static int nct6694_usb_probe(struct usb_interface *iface,
+			     const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(iface);
+	struct usb_endpoint_descriptor *int_endpoint;
+	struct usb_host_interface *interface;
+	struct device *dev = &iface->dev;
+	struct nct6694 *nct6694;
+	int pipe, maxp;
+	int ret;
+
+	nct6694 = devm_kzalloc(dev, sizeof(*nct6694), GFP_KERNEL);
+	if (!nct6694)
+		return -ENOMEM;
+
+	pipe = usb_rcvintpipe(udev, NCT6694_INT_IN_EP);
+	maxp = usb_maxpacket(udev, pipe);
+
+	nct6694->usb_msg = devm_kzalloc(dev, sizeof(union nct6694_usb_msg), GFP_KERNEL);
+	if (!nct6694->usb_msg)
+		return -ENOMEM;
+
+	nct6694->int_buffer = devm_kzalloc(dev, maxp, GFP_KERNEL);
+	if (!nct6694->int_buffer)
+		return -ENOMEM;
+
+	nct6694->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!nct6694->int_in_urb)
+		return -ENOMEM;
+
+	nct6694->domain = irq_domain_add_simple(NULL, NCT6694_NR_IRQS, 0,
+						&nct6694_irq_domain_ops,
+						nct6694);
+	if (!nct6694->domain) {
+		ret = -ENODEV;
+		goto err_urb;
+	}
+
+	nct6694->dev = dev;
+	nct6694->udev = udev;
+	nct6694->timeout = NCT6694_URB_TIMEOUT;	/* Wait until URB completes */
+
+	devm_mutex_init(dev, &nct6694->access_lock);
+	devm_mutex_init(dev, &nct6694->irq_lock);
+
+	interface = iface->cur_altsetting;
+	int_endpoint = &interface->endpoint[0].desc;
+	if (!usb_endpoint_is_int_in(int_endpoint)) {
+		ret = -ENODEV;
+		goto err_urb;
+	}
+	usb_fill_int_urb(nct6694->int_in_urb, udev, pipe,
+			 nct6694->int_buffer, maxp, usb_int_callback,
+			 nct6694, int_endpoint->bInterval);
+	ret = usb_submit_urb(nct6694->int_in_urb, GFP_KERNEL);
+	if (ret)
+		goto err_urb;
+
+	usb_set_intfdata(iface, nct6694);
+
+	ret = mfd_add_hotplug_devices(dev, nct6694_dev, ARRAY_SIZE(nct6694_dev));
+	if (ret)
+		goto err_mfd;
+
+	return 0;
+
+err_mfd:
+	usb_kill_urb(nct6694->int_in_urb);
+err_urb:
+	usb_free_urb(nct6694->int_in_urb);
+	return ret;
+}
+
+static void nct6694_usb_disconnect(struct usb_interface *iface)
+{
+	struct nct6694 *nct6694 = usb_get_intfdata(iface);
+
+	mfd_remove_devices(nct6694->dev);
+	usb_kill_urb(nct6694->int_in_urb);
+	usb_free_urb(nct6694->int_in_urb);
+}
+
+static const struct usb_device_id nct6694_ids[] = {
+	{ USB_DEVICE_AND_INTERFACE_INFO(NCT6694_VENDOR_ID,
+					NCT6694_PRODUCT_ID,
+					0xFF, 0x00, 0x00)},
+	{}
+};
+MODULE_DEVICE_TABLE(usb, nct6694_ids);
+
+static struct usb_driver nct6694_usb_driver = {
+	.name	= "nct6694",
+	.id_table = nct6694_ids,
+	.probe = nct6694_usb_probe,
+	.disconnect = nct6694_usb_disconnect,
+};
+
+module_usb_driver(nct6694_usb_driver);
+
+MODULE_DESCRIPTION("USB core driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/nct6694.h b/include/linux/mfd/nct6694.h
new file mode 100644
index 000000000000..c75a69f04927
--- /dev/null
+++ b/include/linux/mfd/nct6694.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Nuvoton NCT6694 USB transaction and data structure.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#ifndef __MFD_NCT6694_H
+#define __MFD_NCT6694_H
+
+#define NCT6694_VENDOR_ID	0x0416
+#define NCT6694_PRODUCT_ID	0x200B
+#define NCT6694_INT_IN_EP	0x81
+#define NCT6694_BULK_IN_EP	0x02
+#define NCT6694_BULK_OUT_EP	0x03
+
+#define NCT6694_HCTRL_SET	0x40
+#define NCT6694_HCTRL_GET	0x80
+
+#define NCT6694_URB_TIMEOUT	1000
+
+enum nct6694_irq_id {
+	NCT6694_IRQ_GPIO0 = 0,
+	NCT6694_IRQ_GPIO1,
+	NCT6694_IRQ_GPIO2,
+	NCT6694_IRQ_GPIO3,
+	NCT6694_IRQ_GPIO4,
+	NCT6694_IRQ_GPIO5,
+	NCT6694_IRQ_GPIO6,
+	NCT6694_IRQ_GPIO7,
+	NCT6694_IRQ_GPIO8,
+	NCT6694_IRQ_GPIO9,
+	NCT6694_IRQ_GPIOA,
+	NCT6694_IRQ_GPIOB,
+	NCT6694_IRQ_GPIOC,
+	NCT6694_IRQ_GPIOD,
+	NCT6694_IRQ_GPIOE,
+	NCT6694_IRQ_GPIOF,
+	NCT6694_IRQ_CAN1,
+	NCT6694_IRQ_CAN2,
+	NCT6694_IRQ_RTC,
+	NCT6694_NR_IRQS,
+};
+
+enum nct6694_response_err_status {
+	NCT6694_NO_ERROR = 0,
+	NCT6694_FORMAT_ERROR,
+	NCT6694_RESERVED1,
+	NCT6694_RESERVED2,
+	NCT6694_NOT_SUPPORT_ERROR,
+	NCT6694_NO_RESPONSE_ERROR,
+	NCT6694_TIMEOUT_ERROR,
+	NCT6694_PENDING,
+};
+
+struct __packed nct6694_cmd_header {
+	u8 rsv1;
+	u8 mod;
+	union __packed {
+		__le16 offset;
+		struct __packed {
+			u8 cmd;
+			u8 sel;
+		};
+	};
+	u8 hctrl;
+	u8 rsv2;
+	__le16 len;
+};
+
+struct __packed nct6694_response_header {
+	u8 sequence_id;
+	u8 sts;
+	u8 reserved[4];
+	__le16 len;
+};
+
+union __packed nct6694_usb_msg {
+	struct nct6694_cmd_header cmd_header;
+	struct nct6694_response_header response_header;
+};
+
+struct nct6694 {
+	struct device *dev;
+	struct irq_domain *domain;
+	/* Mutex to protect access to the device */
+	struct mutex access_lock;
+	/* Mutex to protect access to the IRQ */
+	struct mutex irq_lock;
+	struct urb *int_in_urb;
+	struct usb_device *udev;
+	union nct6694_usb_msg *usb_msg;
+	unsigned char *int_buffer;
+	unsigned int irq_enable;
+	/* Time in msec to wait for the URB to the complete */
+	long timeout;
+};
+
+int nct6694_read_msg(struct nct6694 *nct6694, const struct nct6694_cmd_header *cmd_hd, void *buf);
+int nct6694_write_msg(struct nct6694 *nct6694, const struct nct6694_cmd_header *cmd_hd, void *buf);
+
+#endif
-- 
2.34.1

[PATCH v7 2/7] gpio: Add Nuvoton NCT6694 GPIO support

[Ming Yu]

This driver supports GPIO and IRQ functionality for NCT6694 MFD
device based on USB interface.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
 MAINTAINERS                 |   1 +
 drivers/gpio/Kconfig        |  12 +
 drivers/gpio/Makefile       |   1 +
 drivers/gpio/gpio-nct6694.c | 458 ++++++++++++++++++++++++++++++++++++
 4 files changed, 472 insertions(+)
 create mode 100644 drivers/gpio/gpio-nct6694.c

diff --git a/MAINTAINERS b/MAINTAINERS
index c700a0b96960..be7cd44a4c88 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16922,6 +16922,7 @@ NUVOTON NCT6694 MFD DRIVER
 M:	Ming Yu <tmyu0@nuvoton.com>
 L:	linux-kernel@vger.kernel.org
 S:	Supported
+F:	drivers/gpio/gpio-nct6694.c
 F:	drivers/mfd/nct6694.c
 F:	include/linux/mfd/nct6694.h
 
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index add5ad29a673..9396de3ea86d 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1461,6 +1461,18 @@ config GPIO_MAX77650
 	  GPIO driver for MAX77650/77651 PMIC from Maxim Semiconductor.
 	  These chips have a single pin that can be configured as GPIO.
 
+config GPIO_NCT6694
+	tristate "Nuvoton NCT6694 GPIO controller support"
+	depends on MFD_NCT6694
+	select GENERIC_IRQ_CHIP
+	select GPIOLIB_IRQCHIP
+	help
+	  This driver supports 8 GPIO pins per bank that can all be interrupt
+	  sources.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called gpio-nct6694.
+
 config GPIO_PALMAS
 	bool "TI PALMAS series PMICs GPIO"
 	depends on MFD_PALMAS
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index af3ba4d81b58..def8487540ab 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -121,6 +121,7 @@ obj-$(CONFIG_GPIO_MT7621)		+= gpio-mt7621.o
 obj-$(CONFIG_GPIO_MVEBU)		+= gpio-mvebu.o
 obj-$(CONFIG_GPIO_MXC)			+= gpio-mxc.o
 obj-$(CONFIG_GPIO_MXS)			+= gpio-mxs.o
+obj-$(CONFIG_GPIO_NCT6694)		+= gpio-nct6694.o
 obj-$(CONFIG_GPIO_NOMADIK)		+= gpio-nomadik.o
 obj-$(CONFIG_GPIO_NPCM_SGPIO)		+= gpio-npcm-sgpio.o
 obj-$(CONFIG_GPIO_OCTEON)		+= gpio-octeon.o
diff --git a/drivers/gpio/gpio-nct6694.c b/drivers/gpio/gpio-nct6694.c
new file mode 100644
index 000000000000..cb688cf8e075
--- /dev/null
+++ b/drivers/gpio/gpio-nct6694.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 GPIO controller driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/bits.h>
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+/*
+ * USB command module type for NCT6694 GPIO controller.
+ * This defines the module type used for communication with the NCT6694
+ * GPIO controller over the USB interface.
+ */
+#define NCT6694_GPIO_MOD	0xFF
+
+#define NCT6694_GPIO_VER	0x90
+#define NCT6694_GPIO_VALID	0x110
+#define NCT6694_GPI_DATA	0x120
+#define NCT6694_GPO_DIR		0x170
+#define NCT6694_GPO_TYPE	0x180
+#define NCT6694_GPO_DATA	0x190
+
+#define NCT6694_GPI_STS		0x130
+#define NCT6694_GPI_CLR		0x140
+#define NCT6694_GPI_FALLING	0x150
+#define NCT6694_GPI_RISING	0x160
+
+#define NCT6694_NR_GPIO		8
+
+struct nct6694_gpio_data {
+	struct nct6694 *nct6694;
+	struct gpio_chip gpio;
+	struct mutex lock;
+	/* Protect irq operation */
+	struct mutex irq_lock;
+
+	unsigned char reg_val;
+	unsigned char irq_trig_falling;
+	unsigned char irq_trig_rising;
+
+	/* Current gpio group */
+	unsigned char group;
+};
+
+static int nct6694_get_direction(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	return !(BIT(offset) & data->reg_val);
+}
+
+static int nct6694_direction_input(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	data->reg_val &= ~BIT(offset);
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
+}
+
+static int nct6694_direction_output(struct gpio_chip *gpio,
+				    unsigned int offset, int val)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	/* Set direction to output */
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	data->reg_val |= BIT(offset);
+	ret = nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	/* Then set output level */
+	cmd_hd.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group);
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	if (val)
+		data->reg_val |= BIT(offset);
+	else
+		data->reg_val &= ~BIT(offset);
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
+}
+
+static int nct6694_get_value(struct gpio_chip *gpio, unsigned int offset)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPO_DIR + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	if (BIT(offset) & data->reg_val) {
+		cmd_hd.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group);
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+		if (ret < 0)
+			return ret;
+
+		return !!(BIT(offset) & data->reg_val);
+	}
+
+	cmd_hd.offset = cpu_to_le16(NCT6694_GPI_DATA + data->group);
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	return !!(BIT(offset) & data->reg_val);
+}
+
+static void nct6694_set_value(struct gpio_chip *gpio, unsigned int offset,
+			      int val)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPO_DATA + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+
+	guard(mutex)(&data->lock);
+
+	nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+
+	if (val)
+		data->reg_val |= BIT(offset);
+	else
+		data->reg_val &= ~BIT(offset);
+
+	nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
+}
+
+static int nct6694_set_config(struct gpio_chip *gpio, unsigned int offset,
+			      unsigned long config)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPO_TYPE + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+		data->reg_val |= BIT(offset);
+		break;
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		data->reg_val &= ~BIT(offset);
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
+}
+
+static int nct6694_init_valid_mask(struct gpio_chip *gpio,
+				   unsigned long *valid_mask,
+				   unsigned int ngpios)
+{
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPIO_VALID + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret < 0)
+		return ret;
+
+	*valid_mask = data->reg_val;
+
+	return ret;
+}
+
+static irqreturn_t nct6694_irq_handler(int irq, void *priv)
+{
+	struct nct6694_gpio_data *data = priv;
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPI_STS + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+	unsigned char status;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	if (ret)
+		return IRQ_NONE;
+
+	status = data->reg_val;
+
+	while (status) {
+		int bit = __ffs(status);
+
+		data->reg_val = BIT(bit);
+		handle_nested_irq(irq_find_mapping(data->gpio.irq.domain, bit));
+		status &= ~BIT(bit);
+		cmd_hd.offset = cpu_to_le16(NCT6694_GPI_CLR + data->group);
+		nct6694_write_msg(data->nct6694, &cmd_hd, &data->reg_val);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int nct6694_get_irq_trig(struct nct6694_gpio_data *data)
+{
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPI_FALLING + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, &data->irq_trig_falling);
+	if (ret)
+		return ret;
+
+	cmd_hd.offset = cpu_to_le16(NCT6694_GPI_RISING + data->group);
+	return nct6694_read_msg(data->nct6694, &cmd_hd, &data->irq_trig_rising);
+}
+
+static void nct6694_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+	gpiochip_disable_irq(gpio, hwirq);
+}
+
+static void nct6694_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+	gpiochip_enable_irq(gpio, hwirq);
+}
+
+static int nct6694_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+	guard(mutex)(&data->lock);
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		data->irq_trig_rising |= BIT(hwirq);
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		data->irq_trig_falling |= BIT(hwirq);
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		data->irq_trig_rising |= BIT(hwirq);
+		data->irq_trig_falling |= BIT(hwirq);
+		break;
+
+	default:
+		return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+static void nct6694_irq_bus_lock(struct irq_data *d)
+{
+	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+
+	mutex_lock(&data->irq_lock);
+}
+
+static void nct6694_irq_bus_sync_unlock(struct irq_data *d)
+{
+	struct gpio_chip *gpio = irq_data_get_irq_chip_data(d);
+	struct nct6694_gpio_data *data = gpiochip_get_data(gpio);
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_GPIO_MOD,
+		.offset = cpu_to_le16(NCT6694_GPI_FALLING + data->group),
+		.len = cpu_to_le16(sizeof(data->reg_val))
+	};
+
+	scoped_guard(mutex, &data->lock) {
+		nct6694_write_msg(data->nct6694, &cmd_hd, &data->irq_trig_falling);
+
+		cmd_hd.offset = cpu_to_le16(NCT6694_GPI_RISING + data->group);
+		nct6694_write_msg(data->nct6694, &cmd_hd, &data->irq_trig_rising);
+	}
+
+	mutex_unlock(&data->irq_lock);
+}
+
+static const struct irq_chip nct6694_irq_chip = {
+	.name			= "gpio-nct6694",
+	.irq_mask		= nct6694_irq_mask,
+	.irq_unmask		= nct6694_irq_unmask,
+	.irq_set_type		= nct6694_irq_set_type,
+	.irq_bus_lock		= nct6694_irq_bus_lock,
+	.irq_bus_sync_unlock	= nct6694_irq_bus_sync_unlock,
+	.flags			= IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static int nct6694_gpio_probe(struct platform_device *pdev)
+{
+	const struct mfd_cell *cell = mfd_get_cell(pdev);
+	struct device *dev = &pdev->dev;
+	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+	struct nct6694_gpio_data *data;
+	struct gpio_irq_chip *girq;
+	int ret, irq, i;
+	char **names;
+
+	irq = irq_create_mapping(nct6694->domain,
+				 NCT6694_IRQ_GPIO0 + cell->id);
+	if (!irq)
+		return -EINVAL;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	names = devm_kcalloc(dev, NCT6694_NR_GPIO, sizeof(char *),
+			     GFP_KERNEL);
+	if (!names)
+		return -ENOMEM;
+
+	for (i = 0; i < NCT6694_NR_GPIO; i++) {
+		names[i] = devm_kasprintf(dev, GFP_KERNEL, "GPIO%X%d",
+					  cell->id, i);
+		if (!names[i])
+			return -ENOMEM;
+	}
+
+	data->nct6694 = nct6694;
+	data->group = cell->id;
+
+	data->gpio.names		= (const char * const*)names;
+	data->gpio.label		= pdev->name;
+	data->gpio.direction_input	= nct6694_direction_input;
+	data->gpio.get			= nct6694_get_value;
+	data->gpio.direction_output	= nct6694_direction_output;
+	data->gpio.set			= nct6694_set_value;
+	data->gpio.get_direction	= nct6694_get_direction;
+	data->gpio.set_config		= nct6694_set_config;
+	data->gpio.init_valid_mask	= nct6694_init_valid_mask;
+	data->gpio.base			= -1;
+	data->gpio.can_sleep		= false;
+	data->gpio.owner		= THIS_MODULE;
+	data->gpio.ngpio		= NCT6694_NR_GPIO;
+
+	devm_mutex_init(dev, &data->lock);
+	devm_mutex_init(dev, &data->irq_lock);
+
+	ret = nct6694_get_irq_trig(data);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get irq trigger type\n");
+
+	girq = &data->gpio.irq;
+	gpio_irq_chip_set_chip(girq, &nct6694_irq_chip);
+	girq->parent_handler = NULL;
+	girq->num_parents = 0;
+	girq->parents = NULL;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_level_irq;
+	girq->threaded = true;
+
+	ret = devm_request_threaded_irq(dev, irq, NULL, nct6694_irq_handler,
+					IRQF_ONESHOT | IRQF_SHARED,
+					"gpio-nct6694", data);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to request irq\n");
+
+	return devm_gpiochip_add_data(dev, &data->gpio, data);
+}
+
+static struct platform_driver nct6694_gpio_driver = {
+	.driver = {
+		.name	= "gpio-nct6694",
+	},
+	.probe		= nct6694_gpio_probe,
+};
+
+module_platform_driver(nct6694_gpio_driver);
+
+MODULE_DESCRIPTION("USB-GPIO controller driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-gpio");
-- 
2.34.1

[PATCH v7 3/7] i2c: Add Nuvoton NCT6694 I2C support

[Ming Yu]

This driver supports I2C adapter functionality for NCT6694 MFD
device based on USB interface, each I2C controller use default
baudrate(100K).

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
 MAINTAINERS                      |   1 +
 drivers/i2c/busses/Kconfig       |  10 ++
 drivers/i2c/busses/Makefile      |   1 +
 drivers/i2c/busses/i2c-nct6694.c | 152 +++++++++++++++++++++++++++++++
 4 files changed, 164 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-nct6694.c

diff --git a/MAINTAINERS b/MAINTAINERS
index be7cd44a4c88..1327e7a6e507 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16923,6 +16923,7 @@ M:	Ming Yu <tmyu0@nuvoton.com>
 L:	linux-kernel@vger.kernel.org
 S:	Supported
 F:	drivers/gpio/gpio-nct6694.c
+F:	drivers/i2c/busses/i2c-nct6694.c
 F:	drivers/mfd/nct6694.c
 F:	include/linux/mfd/nct6694.h
 
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index fc438f445771..d0753d0adaae 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1329,6 +1329,16 @@ config I2C_LJCA
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-ljca.
 
+config I2C_NCT6694
+	tristate "Nuvoton NCT6694 I2C adapter support"
+	depends on MFD_NCT6694
+	help
+	  If you say yes to this option, support will be included for Nuvoton
+	  NCT6694, a USB to I2C interface.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called i2c-nct6694.
+
 config I2C_CP2615
 	tristate "Silicon Labs CP2615 USB sound card and I2C adapter"
 	depends on USB
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 1c2a4510abe4..c5a60116dd54 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -133,6 +133,7 @@ obj-$(CONFIG_I2C_GXP)		+= i2c-gxp.o
 obj-$(CONFIG_I2C_DIOLAN_U2C)	+= i2c-diolan-u2c.o
 obj-$(CONFIG_I2C_DLN2)		+= i2c-dln2.o
 obj-$(CONFIG_I2C_LJCA)		+= i2c-ljca.o
+obj-$(CONFIG_I2C_NCT6694)	+= i2c-nct6694.o
 obj-$(CONFIG_I2C_CP2615) += i2c-cp2615.o
 obj-$(CONFIG_I2C_PARPORT)	+= i2c-parport.o
 obj-$(CONFIG_I2C_PCI1XXXX)	+= i2c-mchp-pci1xxxx.o
diff --git a/drivers/i2c/busses/i2c-nct6694.c b/drivers/i2c/busses/i2c-nct6694.c
new file mode 100644
index 000000000000..eb5b44182b5b
--- /dev/null
+++ b/drivers/i2c/busses/i2c-nct6694.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 I2C adapter driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+/*
+ * USB command module type for NCT6694 I2C controller.
+ * This defines the module type used for communication with the NCT6694
+ * I2C controller over the USB interface.
+ */
+#define NCT6694_I2C_MOD		0x03
+
+/* Command 00h - I2C Deliver */
+#define NCT6694_I2C_DELIVER	0x00
+#define NCT6694_I2C_DELIVER_SEL	0x00
+
+enum i2c_baudrate {
+	I2C_BR_25K = 0,
+	I2C_BR_50K,
+	I2C_BR_100K,
+	I2C_BR_200K,
+	I2C_BR_400K,
+	I2C_BR_800K,
+	I2C_BR_1M
+};
+
+struct __packed nct6694_i2c_deliver {
+	u8 port;
+	u8 br;
+	u8 addr;
+	u8 w_cnt;
+	u8 r_cnt;
+	u8 rsv[11];
+	u8 write_data[0x40];
+	u8 read_data[0x40];
+};
+
+struct nct6694_i2c_data {
+	struct nct6694 *nct6694;
+	struct i2c_adapter adapter;
+	struct nct6694_i2c_deliver deliver;
+	unsigned char port;
+	unsigned char br;
+};
+
+static int nct6694_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	struct nct6694_i2c_data *data = adap->algo_data;
+	struct nct6694_i2c_deliver *deliver = &data->deliver;
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_I2C_MOD,
+		.cmd = NCT6694_I2C_DELIVER,
+		.sel = NCT6694_I2C_DELIVER_SEL,
+		.len = cpu_to_le16(sizeof(*deliver))
+	};
+	int ret, i;
+
+	for (i = 0; i < num ; i++) {
+		struct i2c_msg *msg_temp = &msgs[i];
+
+		memset(deliver, 0, sizeof(*deliver));
+
+		if (msg_temp->len > 64)
+			return -EPROTO;
+
+		deliver->port = data->port;
+		deliver->br = data->br;
+		deliver->addr = i2c_8bit_addr_from_msg(msg_temp);
+		if (msg_temp->flags & I2C_M_RD) {
+			deliver->r_cnt = msg_temp->len;
+			ret = nct6694_write_msg(data->nct6694, &cmd_hd, deliver);
+			if (ret < 0)
+				return ret;
+
+			memcpy(msg_temp->buf, deliver->read_data, msg_temp->len);
+		} else {
+			deliver->w_cnt = msg_temp->len;
+			memcpy(deliver->write_data, msg_temp->buf, msg_temp->len);
+			ret = nct6694_write_msg(data->nct6694, &cmd_hd, deliver);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	return num;
+}
+
+static u32 nct6694_func(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm algorithm = {
+	.master_xfer = nct6694_xfer,
+	.functionality = nct6694_func,
+};
+
+static int nct6694_i2c_probe(struct platform_device *pdev)
+{
+	const struct mfd_cell *cell = mfd_get_cell(pdev);
+	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+	struct nct6694_i2c_data *data;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->nct6694 = nct6694;
+	data->port = cell->id;
+	data->br = I2C_BR_100K;
+
+	sprintf(data->adapter.name, "NCT6694 I2C Adapter %d", cell->id);
+	data->adapter.owner = THIS_MODULE;
+	data->adapter.algo = &algorithm;
+	data->adapter.dev.parent = &pdev->dev;
+	data->adapter.algo_data = data;
+
+	platform_set_drvdata(pdev, data);
+
+	return i2c_add_adapter(&data->adapter);
+}
+
+static void nct6694_i2c_remove(struct platform_device *pdev)
+{
+	struct nct6694_i2c_data *data = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&data->adapter);
+}
+
+static struct platform_driver nct6694_i2c_driver = {
+	.driver = {
+		.name	= "i2c-nct6694",
+	},
+	.probe		= nct6694_i2c_probe,
+	.remove		= nct6694_i2c_remove,
+};
+
+module_platform_driver(nct6694_i2c_driver);
+
+MODULE_DESCRIPTION("USB-I2C adapter driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-i2c");
-- 
2.34.1

[PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Ming Yu]

This driver supports Socket CANFD functionality for NCT6694 MFD
device based on USB interface.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
 MAINTAINERS                         |   1 +
 drivers/net/can/usb/Kconfig         |  11 +
 drivers/net/can/usb/Makefile        |   1 +
 drivers/net/can/usb/nct6694_canfd.c | 809 ++++++++++++++++++++++++++++
 4 files changed, 822 insertions(+)
 create mode 100644 drivers/net/can/usb/nct6694_canfd.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 1327e7a6e507..8aa611504172 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16925,6 +16925,7 @@ S:	Supported
 F:	drivers/gpio/gpio-nct6694.c
 F:	drivers/i2c/busses/i2c-nct6694.c
 F:	drivers/mfd/nct6694.c
+F:	drivers/net/can/usb/nct6694_canfd.c
 F:	include/linux/mfd/nct6694.h
 
 NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
index 9dae0c71a2e1..759e724a67cf 100644
--- a/drivers/net/can/usb/Kconfig
+++ b/drivers/net/can/usb/Kconfig
@@ -133,6 +133,17 @@ config CAN_MCBA_USB
 	  This driver supports the CAN BUS Analyzer interface
 	  from Microchip (http://www.microchip.com/development-tools/).
 
+config CAN_NCT6694
+	tristate "Nuvoton NCT6694 Socket CANfd support"
+	depends on MFD_NCT6694
+	select CAN_RX_OFFLOAD
+	help
+	  If you say yes to this option, support will be included for Nuvoton
+	  NCT6694, a USB device to socket CANfd controller.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called nct6694_canfd.
+
 config CAN_PEAK_USB
 	tristate "PEAK PCAN-USB/USB Pro interfaces for CAN 2.0b/CAN-FD"
 	help
diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
index 8b11088e9a59..fcafb1ac262e 100644
--- a/drivers/net/can/usb/Makefile
+++ b/drivers/net/can/usb/Makefile
@@ -11,5 +11,6 @@ obj-$(CONFIG_CAN_F81604) += f81604.o
 obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
 obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb/
 obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o
+obj-$(CONFIG_CAN_NCT6694) += nct6694_canfd.o
 obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
 obj-$(CONFIG_CAN_UCAN) += ucan.o
diff --git a/drivers/net/can/usb/nct6694_canfd.c b/drivers/net/can/usb/nct6694_canfd.c
new file mode 100644
index 000000000000..a7527020ff71
--- /dev/null
+++ b/drivers/net/can/usb/nct6694_canfd.c
@@ -0,0 +1,809 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 Socket CANfd driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/can/dev.h>
+#include <linux/can/rx-offload.h>
+#include <linux/ethtool.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/platform_device.h>
+
+#define DRVNAME "nct6694_canfd"
+
+/*
+ * USB command module type for NCT6694 CANfd controller.
+ * This defines the module type used for communication with the NCT6694
+ * CANfd controller over the USB interface.
+ */
+#define NCT6694_CAN_MOD			0x05
+
+/* Command 00h - CAN Setting and Initialization */
+#define NCT6694_CAN_SETTING		0x00
+#define NCT6694_CAN_SETTING_CTRL1_MON	BIT(0)
+#define NCT6694_CAN_SETTING_CTRL1_NISO	BIT(1)
+#define NCT6694_CAN_SETTING_CTRL1_LBCK	BIT(2)
+
+/* Command 01h - CAN Information */
+#define NCT6694_CAN_INFORMATION		0x01
+#define NCT6694_CAN_INFORMATION_SEL	0x00
+
+/* Command 02h - CAN Event */
+#define NCT6694_CAN_EVENT		0x02
+#define NCT6694_CAN_EVENT_SEL(idx, mask)	\
+	((idx ? 0x80 : 0x00) | ((mask) & 0x7F))
+
+#define NCT6694_CAN_EVENT_MASK		GENMASK(5, 0)
+#define NCT6694_CAN_EVT_TX_FIFO_EMPTY	BIT(7)	/* Read-clear */
+#define NCT6694_CAN_EVT_RX_DATA_LOST	BIT(5)	/* Read-clear */
+#define NCT6694_CAN_EVT_RX_DATA_IN	BIT(7)	/* Read-clear*/
+
+/* Command 10h - CAN Deliver */
+#define NCT6694_CAN_DELIVER		0x10
+#define NCT6694_CAN_DELIVER_SEL(buf_cnt)	\
+	((buf_cnt) & 0xFF)
+
+/* Command 11h - CAN Receive */
+#define NCT6694_CAN_RECEIVE		0x11
+#define NCT6694_CAN_RECEIVE_SEL(idx, buf_cnt)	\
+	((idx ? 0x80 : 0x00) | ((buf_cnt) & 0x7F))
+
+#define NCT6694_CAN_FRAME_TAG_CAN0	0xC0
+#define NCT6694_CAN_FRAME_TAG_CAN1	0xC1
+#define NCT6694_CAN_FRAME_FLAG_EFF	BIT(0)
+#define NCT6694_CAN_FRAME_FLAG_RTR	BIT(1)
+#define NCT6694_CAN_FRAME_FLAG_FD	BIT(2)
+#define NCT6694_CAN_FRAME_FLAG_BRS	BIT(3)
+#define NCT6694_CAN_FRAME_FLAG_ERR	BIT(4)
+
+#define NCT6694_NAPI_WEIGHT		32
+
+enum nct6694_event_err {
+	NCT6694_CAN_EVT_ERR_NO_ERROR = 0,
+	NCT6694_CAN_EVT_ERR_CRC_ERROR,
+	NCT6694_CAN_EVT_ERR_STUFF_ERROR,
+	NCT6694_CAN_EVT_ERR_ACK_ERROR,
+	NCT6694_CAN_EVT_ERR_FORM_ERROR,
+	NCT6694_CAN_EVT_ERR_BIT_ERROR,
+	NCT6694_CAN_EVT_ERR_TIMEOUT_ERROR,
+	NCT6694_CAN_EVT_ERR_UNKNOWN_ERROR,
+};
+
+enum nct6694_event_status {
+	NCT6694_CAN_EVT_STS_ERROR_ACTIVE = 0,
+	NCT6694_CAN_EVT_STS_ERROR_PASSIVE,
+	NCT6694_CAN_EVT_STS_BUS_OFF,
+	NCT6694_CAN_EVT_STS_WARNING,
+};
+
+struct __packed nct6694_can_setting {
+	__le32 nbr;
+	__le32 dbr;
+	u8 active;
+	u8 reserved[3];
+	__le16 ctrl1;
+	__le16 ctrl2;
+	__le32 nbtp;
+	__le32 dbtp;
+};
+
+struct __packed nct6694_can_information {
+	u8 tx_fifo_cnt;
+	u8 rx_fifo_cnt;
+	u8 reserved[2];
+	__le32 can_clk;
+};
+
+struct __packed nct6694_can_event {
+	u8 err;
+	u8 status;
+	u8 tx_evt;
+	u8 rx_evt;
+	u8 rec;
+	u8 tec;
+	u8 reserved[2];
+};
+
+struct __packed nct6694_can_frame {
+	u8 tag;
+	u8 flag;
+	u8 reserved;
+	u8 length;
+	__le32 id;
+	u8 data[CANFD_MAX_DLEN];
+};
+
+struct nct6694_can_priv {
+	struct can_priv can;	/* must be the first member */
+	struct can_rx_offload offload;
+	struct net_device *ndev;
+	struct nct6694 *nct6694;
+	struct workqueue_struct *wq;
+	struct work_struct tx_work;
+	struct nct6694_can_frame tx;
+	struct nct6694_can_frame rx;
+	struct nct6694_can_event event[2];
+	struct can_berr_counter bec;
+	unsigned char can_idx;
+};
+
+static inline struct nct6694_can_priv *rx_offload_to_priv(struct can_rx_offload *offload)
+{
+	return container_of(offload, struct nct6694_can_priv, offload);
+}
+
+static const struct can_bittiming_const nct6694_can_bittiming_nominal_const = {
+	.name = DRVNAME,
+	.tseg1_min = 2,
+	.tseg1_max = 256,
+	.tseg2_min = 2,
+	.tseg2_max = 128,
+	.sjw_max = 128,
+	.brp_min = 1,
+	.brp_max = 511,
+	.brp_inc = 1,
+};
+
+static const struct can_bittiming_const nct6694_can_bittiming_data_const = {
+	.name = DRVNAME,
+	.tseg1_min = 1,
+	.tseg1_max = 32,
+	.tseg2_min = 1,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 31,
+	.brp_inc = 1,
+};
+
+static void nct6694_can_rx_offload(struct can_rx_offload *offload,
+				   struct sk_buff *skb)
+{
+	struct nct6694_can_priv *priv = rx_offload_to_priv(offload);
+	int ret;
+
+	ret = can_rx_offload_queue_tail(offload, skb);
+	if (ret)
+		priv->ndev->stats.rx_fifo_errors++;
+}
+
+static void nct6694_can_handle_lost_msg(struct net_device *ndev)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	struct can_frame *cf;
+	struct sk_buff *skb;
+
+	netdev_err(ndev, "RX FIFO overflow, message(s) lost.\n");
+
+	stats->rx_errors++;
+	stats->rx_over_errors++;
+
+	skb = alloc_can_err_skb(ndev, &cf);
+	if (!skb)
+		return;
+
+	cf->can_id |= CAN_ERR_CRTL;
+	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+
+	nct6694_can_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_can_rx(struct net_device *ndev, u8 rx_evt)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+	struct nct6694_can_frame *frame = &priv->rx;
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_CAN_MOD,
+		.cmd = NCT6694_CAN_RECEIVE,
+		.sel = NCT6694_CAN_RECEIVE_SEL(priv->can_idx, 1),
+		.len = cpu_to_le16(sizeof(*frame))
+	};
+	struct sk_buff *skb;
+	int ret;
+
+	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, frame);
+	if (ret)
+		return;
+
+	if (frame->flag & NCT6694_CAN_FRAME_FLAG_FD) {
+		struct canfd_frame *cfd;
+
+		skb = alloc_canfd_skb(priv->ndev, &cfd);
+		if (!skb)
+			return;
+
+		cfd->can_id = le32_to_cpu(frame->id);
+		cfd->len = canfd_sanitize_len(frame->length);
+		if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
+			cfd->can_id |= CAN_EFF_FLAG;
+		if (frame->flag & NCT6694_CAN_FRAME_FLAG_BRS)
+			cfd->flags |= CANFD_BRS;
+		if (frame->flag & NCT6694_CAN_FRAME_FLAG_ERR)
+			cfd->flags |= CANFD_ESI;
+
+		memcpy(cfd->data, frame->data, cfd->len);
+	} else {
+		struct can_frame *cf;
+
+		skb = alloc_can_skb(priv->ndev, &cf);
+		if (!skb)
+			return;
+
+		cf->can_id = le32_to_cpu(frame->id);
+		cf->len = min_t(u8, frame->length, CAN_MAX_DLEN);
+		if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
+			cf->can_id |= CAN_EFF_FLAG;
+
+		if (frame->flag & NCT6694_CAN_FRAME_FLAG_RTR)
+			cf->can_id |= CAN_RTR_FLAG;
+		else
+			memcpy(cf->data, frame->data, cf->len);
+	}
+
+	nct6694_can_rx_offload(&priv->offload, skb);
+}
+
+static int nct6694_can_get_berr_counter(const struct net_device *ndev,
+					struct can_berr_counter *bec)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+
+	*bec = priv->bec;
+
+	return 0;
+}
+
+static void nct6694_can_handle_state_change(struct net_device *ndev,
+					    enum can_state new_state)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+	struct can_berr_counter bec;
+	struct can_frame *cf;
+	struct sk_buff *skb;
+
+	skb = alloc_can_err_skb(ndev, &cf);
+
+	nct6694_can_get_berr_counter(ndev, &bec);
+
+	switch (new_state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		priv->can.can_stats.error_warning++;
+		priv->can.state = CAN_STATE_ERROR_ACTIVE;
+		if (cf)
+			cf->data[1] |= CAN_ERR_CRTL_ACTIVE;
+		break;
+	case CAN_STATE_ERROR_WARNING:
+		priv->can.can_stats.error_warning++;
+		priv->can.state = CAN_STATE_ERROR_WARNING;
+		if (cf) {
+			cf->can_id |= CAN_ERR_CRTL;
+			if (bec.txerr > bec.rxerr)
+				cf->data[1] = CAN_ERR_CRTL_TX_WARNING;
+			else
+				cf->data[1] = CAN_ERR_CRTL_RX_WARNING;
+			cf->data[6] = bec.txerr;
+			cf->data[7] = bec.rxerr;
+		}
+		break;
+	case CAN_STATE_ERROR_PASSIVE:
+		priv->can.can_stats.error_passive++;
+		priv->can.state = CAN_STATE_ERROR_PASSIVE;
+		if (cf) {
+			cf->can_id |= CAN_ERR_CRTL;
+			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
+			if (bec.txerr >= CAN_ERROR_PASSIVE_THRESHOLD)
+				cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
+			cf->data[6] = bec.txerr;
+			cf->data[7] = bec.rxerr;
+		}
+		break;
+	case CAN_STATE_BUS_OFF:
+		priv->can.state = CAN_STATE_BUS_OFF;
+		priv->can.can_stats.bus_off++;
+		if (cf)
+			cf->can_id |= CAN_ERR_BUSOFF;
+		can_free_echo_skb(ndev, 0, NULL);
+		netif_stop_queue(ndev);
+		can_bus_off(ndev);
+		break;
+	default:
+		break;
+	}
+
+	nct6694_can_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_can_handle_state_errors(struct net_device *ndev, u8 status)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+
+	if (status == NCT6694_CAN_EVT_STS_ERROR_ACTIVE &&
+	    priv->can.state != CAN_STATE_ERROR_ACTIVE) {
+		netdev_dbg(ndev, "Error, entered active state\n");
+		nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_ACTIVE);
+	}
+
+	if (status == NCT6694_CAN_EVT_STS_WARNING &&
+	    priv->can.state != CAN_STATE_ERROR_WARNING) {
+		netdev_dbg(ndev, "Error, entered warning state\n");
+		nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_WARNING);
+	}
+
+	if (status == NCT6694_CAN_EVT_STS_ERROR_PASSIVE &&
+	    priv->can.state != CAN_STATE_ERROR_PASSIVE) {
+		netdev_dbg(ndev, "Error, entered passive state\n");
+		nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_PASSIVE);
+	}
+
+	if (status == NCT6694_CAN_EVT_STS_BUS_OFF &&
+	    priv->can.state != CAN_STATE_BUS_OFF) {
+		netdev_dbg(ndev, "Error, entered bus-off state\n");
+		nct6694_can_handle_state_change(ndev, CAN_STATE_BUS_OFF);
+	}
+}
+
+static void nct6694_can_handle_bus_err(struct net_device *ndev, u8 bus_err)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+	struct can_frame *cf;
+	struct sk_buff *skb;
+
+	if (bus_err == NCT6694_CAN_EVT_ERR_NO_ERROR)
+		return;
+
+	priv->can.can_stats.bus_error++;
+
+	skb = alloc_can_err_skb(ndev, &cf);
+	if (skb)
+		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+	switch (bus_err) {
+	case NCT6694_CAN_EVT_ERR_CRC_ERROR:
+		netdev_dbg(ndev, "CRC error\n");
+		ndev->stats.rx_errors++;
+		if (skb)
+			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+		break;
+
+	case NCT6694_CAN_EVT_ERR_STUFF_ERROR:
+		netdev_dbg(ndev, "Stuff error\n");
+		ndev->stats.rx_errors++;
+		if (skb)
+			cf->data[2] |= CAN_ERR_PROT_STUFF;
+		break;
+
+	case NCT6694_CAN_EVT_ERR_ACK_ERROR:
+		netdev_dbg(ndev, "Ack error\n");
+		ndev->stats.tx_errors++;
+		if (skb) {
+			cf->can_id |= CAN_ERR_ACK;
+			cf->data[2] |= CAN_ERR_PROT_TX;
+		}
+		break;
+
+	case NCT6694_CAN_EVT_ERR_FORM_ERROR:
+		netdev_dbg(ndev, "Form error\n");
+		ndev->stats.rx_errors++;
+		if (skb)
+			cf->data[2] |= CAN_ERR_PROT_FORM;
+		break;
+
+	case NCT6694_CAN_EVT_ERR_BIT_ERROR:
+		netdev_dbg(ndev, "Bit error\n");
+		ndev->stats.tx_errors++;
+		if (skb)
+			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT;
+		break;
+
+	default:
+		break;
+	}
+
+	nct6694_can_rx_offload(&priv->offload, skb);
+}
+
+static void nct6694_can_tx_irq(struct net_device *ndev)
+{
+	struct net_device_stats *stats = &ndev->stats;
+
+	stats->tx_bytes += can_get_echo_skb(ndev, 0, NULL);
+	stats->tx_packets++;
+	netif_wake_queue(ndev);
+}
+
+static irqreturn_t nct6694_can_irq(int irq, void *data)
+{
+	struct net_device *ndev = data;
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+	struct nct6694_can_event *evt = priv->event;
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_CAN_MOD,
+		.cmd = NCT6694_CAN_EVENT,
+		.sel = NCT6694_CAN_EVENT_SEL(priv->can_idx, NCT6694_CAN_EVENT_MASK),
+		.len = cpu_to_le16(sizeof(priv->event))
+	};
+	irqreturn_t handled = IRQ_NONE;
+	int can_idx = priv->can_idx;
+	int ret;
+
+	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, evt);
+	if (ret < 0)
+		return handled;
+
+	if (priv->event[can_idx].rx_evt & NCT6694_CAN_EVT_RX_DATA_IN) {
+		nct6694_can_rx(ndev, priv->event[can_idx].rx_evt);
+		handled = IRQ_HANDLED;
+	}
+
+	if (priv->event[can_idx].rx_evt & NCT6694_CAN_EVT_RX_DATA_LOST) {
+		nct6694_can_handle_lost_msg(ndev);
+		handled = IRQ_HANDLED;
+	}
+
+	if (priv->event[can_idx].status) {
+		nct6694_can_handle_state_errors(ndev, priv->event[can_idx].status);
+		handled = IRQ_HANDLED;
+	}
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
+		nct6694_can_handle_bus_err(ndev, priv->event[can_idx].err);
+		handled = IRQ_HANDLED;
+	}
+
+	if (handled)
+		can_rx_offload_threaded_irq_finish(&priv->offload);
+
+	if (priv->event[can_idx].tx_evt & NCT6694_CAN_EVT_TX_FIFO_EMPTY)
+		nct6694_can_tx_irq(ndev);
+
+	priv->bec.rxerr = priv->event[can_idx].rec;
+	priv->bec.txerr = priv->event[can_idx].tec;
+
+	return handled;
+}
+
+static void nct6694_can_tx_work(struct work_struct *work)
+{
+	struct nct6694_can_priv *priv = container_of(work,
+						     struct nct6694_can_priv,
+						     tx_work);
+	struct nct6694_can_frame *frame = &priv->tx;
+	struct net_device *ndev = priv->ndev;
+	struct net_device_stats *stats = &ndev->stats;
+	struct sk_buff *skb = priv->can.echo_skb[0];
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_CAN_MOD,
+		.cmd = NCT6694_CAN_DELIVER,
+		.sel = NCT6694_CAN_DELIVER_SEL(1),
+		.len = cpu_to_le16(sizeof(*frame))
+	};
+	u32 txid;
+	int err;
+
+	memset(frame, 0, sizeof(*frame));
+
+	if (priv->can_idx == 0)
+		frame->tag = NCT6694_CAN_FRAME_TAG_CAN0;
+	else
+		frame->tag = NCT6694_CAN_FRAME_TAG_CAN1;
+
+	if (can_is_canfd_skb(skb)) {
+		struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+		if (cfd->flags & CANFD_BRS)
+			frame->flag |= NCT6694_CAN_FRAME_FLAG_BRS;
+
+		if (cfd->can_id & CAN_EFF_FLAG) {
+			txid = cfd->can_id & CAN_EFF_MASK;
+			frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
+		} else {
+			txid = cfd->can_id & CAN_SFF_MASK;
+		}
+		frame->flag |= NCT6694_CAN_FRAME_FLAG_FD;
+		frame->id = cpu_to_le32(txid);
+		frame->length = cfd->len;
+
+		memcpy(frame->data, cfd->data, cfd->len);
+	} else {
+		struct can_frame *cf = (struct can_frame *)skb->data;
+
+		if (cf->can_id & CAN_EFF_FLAG) {
+			txid = cf->can_id & CAN_EFF_MASK;
+			frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
+		} else {
+			txid = cf->can_id & CAN_SFF_MASK;
+		}
+
+		if (cf->can_id & CAN_RTR_FLAG)
+			frame->flag |= NCT6694_CAN_FRAME_FLAG_RTR;
+		else
+			memcpy(frame->data, cf->data, cf->len);
+
+		frame->id = cpu_to_le32(txid);
+		frame->length = cf->len;
+	}
+
+	err = nct6694_write_msg(priv->nct6694, &cmd_hd, frame);
+	if (err) {
+		netdev_err(ndev, "%s: TX FIFO is full!\n", __func__);
+		can_free_echo_skb(ndev, 0, NULL);
+		stats->tx_dropped++;
+		stats->tx_errors++;
+		netif_wake_queue(ndev);
+	}
+}
+
+static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb,
+					  struct net_device *ndev)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+
+	if (can_dev_dropped_skb(ndev, skb))
+		return NETDEV_TX_OK;
+
+	netif_stop_queue(ndev);
+	can_put_echo_skb(skb, ndev, 0, 0);
+	queue_work(priv->wq, &priv->tx_work);
+
+	return NETDEV_TX_OK;
+}
+
+static int nct6694_can_start(struct net_device *ndev)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+	struct nct6694_can_setting *setting;
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_CAN_MOD,
+		.cmd = NCT6694_CAN_SETTING,
+		.sel = priv->can_idx,
+		.len = cpu_to_le16(sizeof(*setting))
+	};
+	const struct can_bittiming *n_bt = &priv->can.bittiming;
+	const struct can_bittiming *d_bt = &priv->can.data_bittiming;
+	int ret;
+
+	setting = kzalloc(sizeof(*setting), GFP_KERNEL);
+	if (!setting)
+		return -ENOMEM;
+
+	setting->nbr = cpu_to_le32(n_bt->bitrate);
+	setting->dbr = cpu_to_le32(d_bt->bitrate);
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+		setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_MON);
+
+	if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&
+	    priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
+		setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_NISO);
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
+		setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_LBCK);
+
+	ret = nct6694_write_msg(priv->nct6694, &cmd_hd, setting);
+	if (ret)
+		goto exit;
+
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+exit:
+	kfree(setting);
+	return ret;
+}
+
+static int nct6694_can_stop(struct net_device *ndev)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+
+	netif_stop_queue(ndev);
+	free_irq(ndev->irq, ndev);
+	destroy_workqueue(priv->wq);
+	priv->wq = NULL;
+	priv->can.state = CAN_STATE_STOPPED;
+	can_rx_offload_disable(&priv->offload);
+	close_candev(ndev);
+
+	return 0;
+}
+
+static int nct6694_can_set_mode(struct net_device *ndev, enum can_mode mode)
+{
+	switch (mode) {
+	case CAN_MODE_START:
+		nct6694_can_start(ndev);
+		netif_wake_queue(ndev);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_can_open(struct net_device *ndev)
+{
+	struct nct6694_can_priv *priv = netdev_priv(ndev);
+	int ret;
+
+	ret = open_candev(ndev);
+	if (ret)
+		return ret;
+
+	can_rx_offload_enable(&priv->offload);
+
+	ret = request_threaded_irq(ndev->irq, NULL,
+				   nct6694_can_irq, IRQF_ONESHOT,
+				   "nct6694_can", ndev);
+	if (ret) {
+		netdev_err(ndev, "Failed to request IRQ\n");
+		goto close_candev;
+	}
+
+	priv->wq = alloc_ordered_workqueue("%s-nct6694_wq",
+					   WQ_FREEZABLE | WQ_MEM_RECLAIM,
+					   ndev->name);
+	if (!priv->wq) {
+		ret = -ENOMEM;
+		goto free_irq;
+	}
+
+	ret = nct6694_can_start(ndev);
+	if (ret)
+		goto destroy_wq;
+
+	netif_start_queue(ndev);
+
+	return 0;
+
+destroy_wq:
+	destroy_workqueue(priv->wq);
+free_irq:
+	free_irq(ndev->irq, ndev);
+close_candev:
+	can_rx_offload_disable(&priv->offload);
+	close_candev(ndev);
+	return ret;
+}
+
+static const struct net_device_ops nct6694_can_netdev_ops = {
+	.ndo_open = nct6694_can_open,
+	.ndo_stop = nct6694_can_stop,
+	.ndo_start_xmit = nct6694_can_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
+};
+
+static const struct ethtool_ops nct6694_can_ethtool_ops = {
+	.get_ts_info = ethtool_op_get_ts_info,
+};
+
+static int nct6694_can_get_clock(struct nct6694_can_priv *priv)
+{
+	struct nct6694_can_information *info;
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_CAN_MOD,
+		.cmd = NCT6694_CAN_INFORMATION,
+		.sel = NCT6694_CAN_INFORMATION_SEL,
+		.len = cpu_to_le16(sizeof(*info))
+	};
+	int ret, can_clk;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, info);
+	if (ret) {
+		kfree(info);
+		return ret;
+	}
+
+	can_clk = le32_to_cpu(info->can_clk);
+	kfree(info);
+
+	return can_clk;
+}
+
+static int nct6694_can_probe(struct platform_device *pdev)
+{
+	const struct mfd_cell *cell = mfd_get_cell(pdev);
+	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+	struct nct6694_can_priv *priv;
+	struct net_device *ndev;
+	int ret, irq, can_clk;
+
+	irq = irq_create_mapping(nct6694->domain,
+				 NCT6694_IRQ_CAN1 + cell->id);
+	if (!irq)
+		return irq;
+
+	ndev = alloc_candev(sizeof(struct nct6694_can_priv), 1);
+	if (!ndev)
+		return -ENOMEM;
+
+	ndev->irq = irq;
+	ndev->flags |= IFF_ECHO;
+	ndev->dev_port = cell->id;
+	ndev->netdev_ops = &nct6694_can_netdev_ops;
+	ndev->ethtool_ops = &nct6694_can_ethtool_ops;
+
+	priv = netdev_priv(ndev);
+	priv->nct6694 = nct6694;
+	priv->ndev = ndev;
+
+	can_clk = nct6694_can_get_clock(priv);
+	if (can_clk < 0) {
+		ret = dev_err_probe(&pdev->dev, can_clk,
+				    "Failed to get clock\n");
+		goto free_candev;
+	}
+
+	INIT_WORK(&priv->tx_work, nct6694_can_tx_work);
+
+	priv->can_idx = cell->id;
+	priv->can.state = CAN_STATE_STOPPED;
+	priv->can.clock.freq = can_clk;
+	priv->can.bittiming_const = &nct6694_can_bittiming_nominal_const;
+	priv->can.data_bittiming_const = &nct6694_can_bittiming_data_const;
+	priv->can.do_set_mode = nct6694_can_set_mode;
+	priv->can.do_get_berr_counter = nct6694_can_get_berr_counter;
+
+	priv->can.ctrlmode = CAN_CTRLMODE_FD;
+
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK		|
+				       CAN_CTRLMODE_LISTENONLY		|
+				       CAN_CTRLMODE_FD			|
+				       CAN_CTRLMODE_FD_NON_ISO		|
+				       CAN_CTRLMODE_BERR_REPORTING;
+
+	ret = can_rx_offload_add_manual(ndev, &priv->offload,
+					NCT6694_NAPI_WEIGHT);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "Failed to add rx_offload\n");
+		goto free_candev;
+	}
+
+	platform_set_drvdata(pdev, priv);
+	SET_NETDEV_DEV(priv->ndev, &pdev->dev);
+
+	ret = register_candev(priv->ndev);
+	if (ret)
+		goto del_rx_offload;
+
+	return 0;
+
+del_rx_offload:
+	can_rx_offload_del(&priv->offload);
+free_candev:
+	free_candev(ndev);
+	return ret;
+}
+
+static void nct6694_can_remove(struct platform_device *pdev)
+{
+	struct nct6694_can_priv *priv = platform_get_drvdata(pdev);
+
+	cancel_work_sync(&priv->tx_work);
+	unregister_candev(priv->ndev);
+	can_rx_offload_del(&priv->offload);
+	free_candev(priv->ndev);
+}
+
+static struct platform_driver nct6694_can_driver = {
+	.driver = {
+		.name	= DRVNAME,
+	},
+	.probe		= nct6694_can_probe,
+	.remove		= nct6694_can_remove,
+};
+
+module_platform_driver(nct6694_can_driver);
+
+MODULE_DESCRIPTION("USB-CAN FD driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-can");
-- 
2.34.1

[PATCH v7 5/7] watchdog: Add Nuvoton NCT6694 WDT support

[Ming Yu]

This driver supports Watchdog timer functionality for NCT6694 MFD
device based on USB interface.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
 MAINTAINERS                    |   1 +
 drivers/watchdog/Kconfig       |  11 ++
 drivers/watchdog/Makefile      |   1 +
 drivers/watchdog/nct6694_wdt.c | 295 +++++++++++++++++++++++++++++++++
 4 files changed, 308 insertions(+)
 create mode 100644 drivers/watchdog/nct6694_wdt.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 8aa611504172..4889b618abef 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16926,6 +16926,7 @@ F:	drivers/gpio/gpio-nct6694.c
 F:	drivers/i2c/busses/i2c-nct6694.c
 F:	drivers/mfd/nct6694.c
 F:	drivers/net/can/usb/nct6694_canfd.c
+F:	drivers/watchdog/nct6694_wdt.c
 F:	include/linux/mfd/nct6694.h
 
 NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index f81705f8539a..4c4f826368c4 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -748,6 +748,17 @@ config MAX77620_WATCHDOG
 	  MAX77620 chips. To compile this driver as a module,
 	  choose M here: the module will be called max77620_wdt.
 
+config NCT6694_WATCHDOG
+	tristate "Nuvoton NCT6694 watchdog support"
+	depends on MFD_NCT6694
+	select WATCHDOG_CORE
+	help
+	  Say Y here to support Nuvoton NCT6694 watchdog timer
+	  functionality.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called nct6694_wdt.
+
 config IMX2_WDT
 	tristate "IMX2+ Watchdog"
 	depends on ARCH_MXC || ARCH_LAYERSCAPE || COMPILE_TEST
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 8411626fa162..de2a04ff8a92 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -232,6 +232,7 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
 obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
 obj-$(CONFIG_MAX77620_WATCHDOG) += max77620_wdt.o
+obj-$(CONFIG_NCT6694_WATCHDOG) += nct6694_wdt.o
 obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o
 obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
 obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o
diff --git a/drivers/watchdog/nct6694_wdt.c b/drivers/watchdog/nct6694_wdt.c
new file mode 100644
index 000000000000..6f0a6b7a203b
--- /dev/null
+++ b/drivers/watchdog/nct6694_wdt.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 WDT driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/watchdog.h>
+
+#define DRVNAME "nct6694_wdt"
+
+#define NCT6694_DEFAULT_TIMEOUT		10
+#define NCT6694_DEFAULT_PRETIMEOUT	0
+
+/*
+ * USB command module type for NCT6694 WDT controller.
+ * This defines the module type used for communication with the NCT6694
+ * WDT controller over the USB interface.
+ */
+#define NCT6694_WDT_MOD			0x07
+
+/* Command 00h - WDT Setup */
+#define NCT6694_WDT_SETUP		0x00
+#define NCT6694_WDT_SETUP_SEL(idx)	(idx ? 0x01 : 0x00)
+
+/* Command 01h - WDT Command */
+#define NCT6694_WDT_COMMAND		0x01
+#define NCT6694_WDT_COMMAND_SEL(idx)	(idx ? 0x01 : 0x00)
+
+static unsigned int timeout = NCT6694_DEFAULT_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
+
+static unsigned int pretimeout = NCT6694_DEFAULT_PRETIMEOUT;
+module_param(pretimeout, int, 0);
+MODULE_PARM_DESC(pretimeout, "Watchdog pre-timeout in seconds");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+			   __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+enum {
+	NCT6694_ACTION_NONE = 0,
+	NCT6694_ACTION_SIRQ,
+	NCT6694_ACTION_GPO,
+};
+
+struct __packed nct6694_wdt_setup {
+	__le32 pretimeout;
+	__le32 timeout;
+	u8 owner;
+	u8 scratch;
+	u8 control;
+	u8 status;
+	__le32 countdown;
+};
+
+struct __packed nct6694_wdt_cmd {
+	__le32 wdt_cmd;
+	__le32 reserved;
+};
+
+union __packed nct6694_wdt_msg {
+	struct nct6694_wdt_setup setup;
+	struct nct6694_wdt_cmd cmd;
+};
+
+struct nct6694_wdt_data {
+	struct watchdog_device wdev;
+	struct device *dev;
+	struct nct6694 *nct6694;
+	struct mutex lock;
+	union nct6694_wdt_msg *msg;
+	unsigned int wdev_idx;
+};
+
+static int nct6694_wdt_setting(struct watchdog_device *wdev,
+			       u32 timeout_val, u8 timeout_act,
+			       u32 pretimeout_val, u8 pretimeout_act)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	struct nct6694_wdt_setup *setup = &data->msg->setup;
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_WDT_MOD,
+		.cmd = NCT6694_WDT_SETUP,
+		.sel = NCT6694_WDT_SETUP_SEL(data->wdev_idx),
+		.len = cpu_to_le16(sizeof(*setup))
+	};
+	unsigned int timeout_fmt, pretimeout_fmt;
+
+	guard(mutex)(&data->lock);
+
+	if (pretimeout_val == 0)
+		pretimeout_act = NCT6694_ACTION_NONE;
+
+	timeout_fmt = (timeout_val * 1000) | (timeout_act << 24);
+	pretimeout_fmt = (pretimeout_val * 1000) | (pretimeout_act << 24);
+
+	memset(setup, 0, sizeof(*setup));
+	setup->timeout = cpu_to_le32(timeout_fmt);
+	setup->pretimeout = cpu_to_le32(pretimeout_fmt);
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, setup);
+}
+
+static int nct6694_wdt_start(struct watchdog_device *wdev)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	int ret;
+
+	ret = nct6694_wdt_setting(wdev, wdev->timeout, NCT6694_ACTION_GPO,
+				  wdev->pretimeout, NCT6694_ACTION_GPO);
+	if (ret)
+		return ret;
+
+	dev_dbg(data->dev, "Setting WDT(%d): timeout = %d, pretimeout = %d\n",
+		data->wdev_idx, wdev->timeout, wdev->pretimeout);
+
+	return ret;
+}
+
+static int nct6694_wdt_stop(struct watchdog_device *wdev)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	struct nct6694_wdt_cmd *cmd = &data->msg->cmd;
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_WDT_MOD,
+		.cmd = NCT6694_WDT_COMMAND,
+		.sel = NCT6694_WDT_COMMAND_SEL(data->wdev_idx),
+		.len = cpu_to_le16(sizeof(*cmd))
+	};
+
+	guard(mutex)(&data->lock);
+
+	memcpy(&cmd->wdt_cmd, "WDTC", 4);
+	cmd->reserved = 0;
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, cmd);
+}
+
+static int nct6694_wdt_ping(struct watchdog_device *wdev)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	struct nct6694_wdt_cmd *cmd = &data->msg->cmd;
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_WDT_MOD,
+		.cmd = NCT6694_WDT_COMMAND,
+		.sel = NCT6694_WDT_COMMAND_SEL(data->wdev_idx),
+		.len = cpu_to_le16(sizeof(*cmd))
+	};
+
+	guard(mutex)(&data->lock);
+	memcpy(&cmd->wdt_cmd, "WDTS", 4);
+	cmd->reserved = 0;
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, cmd);
+}
+
+static int nct6694_wdt_set_timeout(struct watchdog_device *wdev,
+				   unsigned int new_timeout)
+{
+	int ret;
+
+	ret = nct6694_wdt_setting(wdev, new_timeout, NCT6694_ACTION_GPO,
+				  wdev->pretimeout, NCT6694_ACTION_GPO);
+	if (ret)
+		return ret;
+
+	wdev->timeout = new_timeout;
+
+	return 0;
+}
+
+static int nct6694_wdt_set_pretimeout(struct watchdog_device *wdev,
+				      unsigned int new_pretimeout)
+{
+	int ret;
+
+	ret = nct6694_wdt_setting(wdev, wdev->timeout, NCT6694_ACTION_GPO,
+				  new_pretimeout, NCT6694_ACTION_GPO);
+	if (ret)
+		return ret;
+
+	wdev->pretimeout = new_pretimeout;
+
+	return 0;
+}
+
+static unsigned int nct6694_wdt_get_time(struct watchdog_device *wdev)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	struct nct6694_wdt_setup *setup = &data->msg->setup;
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_WDT_MOD,
+		.cmd = NCT6694_WDT_SETUP,
+		.sel = NCT6694_WDT_SETUP_SEL(data->wdev_idx),
+		.len = cpu_to_le16(sizeof(*setup))
+	};
+	unsigned int timeleft_ms;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, setup);
+	if (ret)
+		return 0;
+
+	timeleft_ms = le32_to_cpu(setup->countdown);
+
+	return timeleft_ms / 1000;
+}
+
+static const struct watchdog_info nct6694_wdt_info = {
+	.options = WDIOF_SETTIMEOUT	|
+		   WDIOF_KEEPALIVEPING	|
+		   WDIOF_MAGICCLOSE	|
+		   WDIOF_PRETIMEOUT,
+	.identity = DRVNAME,
+};
+
+static const struct watchdog_ops nct6694_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = nct6694_wdt_start,
+	.stop = nct6694_wdt_stop,
+	.set_timeout = nct6694_wdt_set_timeout,
+	.set_pretimeout = nct6694_wdt_set_pretimeout,
+	.get_timeleft = nct6694_wdt_get_time,
+	.ping = nct6694_wdt_ping,
+};
+
+static int nct6694_wdt_probe(struct platform_device *pdev)
+{
+	const struct mfd_cell *cell = mfd_get_cell(pdev);
+	struct device *dev = &pdev->dev;
+	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+	struct nct6694_wdt_data *data;
+	struct watchdog_device *wdev;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->msg = devm_kzalloc(dev, sizeof(union nct6694_wdt_msg),
+				 GFP_KERNEL);
+	if (!data->msg)
+		return -ENOMEM;
+
+	data->dev = dev;
+	data->nct6694 = nct6694;
+	data->wdev_idx = cell->id;
+
+	wdev = &data->wdev;
+	wdev->info = &nct6694_wdt_info;
+	wdev->ops = &nct6694_wdt_ops;
+	wdev->timeout = timeout;
+	wdev->pretimeout = pretimeout;
+	if (timeout < pretimeout) {
+		dev_warn(data->dev, "pretimeout < timeout. Setting to zero\n");
+		wdev->pretimeout = 0;
+	}
+
+	wdev->min_timeout = 1;
+	wdev->max_timeout = 255;
+
+	devm_mutex_init(dev, &data->lock);
+
+	platform_set_drvdata(pdev, data);
+
+	watchdog_set_drvdata(&data->wdev, data);
+	watchdog_set_nowayout(&data->wdev, nowayout);
+	watchdog_stop_on_reboot(&data->wdev);
+
+	return devm_watchdog_register_device(dev, &data->wdev);
+}
+
+static struct platform_driver nct6694_wdt_driver = {
+	.driver = {
+		.name	= DRVNAME,
+	},
+	.probe		= nct6694_wdt_probe,
+};
+
+module_platform_driver(nct6694_wdt_driver);
+
+MODULE_DESCRIPTION("USB-WDT driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-wdt");
-- 
2.34.1

[PATCH v7 6/7] hwmon: Add Nuvoton NCT6694 HWMON support

[Ming Yu]

This driver supports Hardware monitor functionality for NCT6694 MFD
device based on USB interface.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
 MAINTAINERS                   |   1 +
 drivers/hwmon/Kconfig         |  10 +
 drivers/hwmon/Makefile        |   1 +
 drivers/hwmon/nct6694-hwmon.c | 947 ++++++++++++++++++++++++++++++++++
 4 files changed, 959 insertions(+)
 create mode 100644 drivers/hwmon/nct6694-hwmon.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 4889b618abef..a9eda4530b07 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16923,6 +16923,7 @@ M:	Ming Yu <tmyu0@nuvoton.com>
 L:	linux-kernel@vger.kernel.org
 S:	Supported
 F:	drivers/gpio/gpio-nct6694.c
+F:	drivers/hwmon/nct6694-hwmon.c
 F:	drivers/i2c/busses/i2c-nct6694.c
 F:	drivers/mfd/nct6694.c
 F:	drivers/net/can/usb/nct6694_canfd.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 4cbaba15d86e..8a7de798a30a 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1638,6 +1638,16 @@ config SENSORS_NCT6683
 	  This driver can also be built as a module. If so, the module
 	  will be called nct6683.
 
+config SENSORS_NCT6694
+	tristate "Nuvoton NCT6694 Hardware Monitor support"
+	depends on MFD_NCT6694
+	help
+	  Say Y here to support Nuvoton NCT6694 hardware monitoring
+	  functionality.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called nct6694-hwmon.
+
 config SENSORS_NCT6775_CORE
 	tristate
 	select REGMAP
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index b7ef0f0562d3..c73898704421 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -168,6 +168,7 @@ obj-$(CONFIG_SENSORS_MLXREG_FAN) += mlxreg-fan.o
 obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
 obj-$(CONFIG_SENSORS_MR75203)	+= mr75203.o
 obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
+obj-$(CONFIG_SENSORS_NCT6694)	+= nct6694-hwmon.o
 obj-$(CONFIG_SENSORS_NCT6775_CORE) += nct6775-core.o
 nct6775-objs			:= nct6775-platform.o
 obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
diff --git a/drivers/hwmon/nct6694-hwmon.c b/drivers/hwmon/nct6694-hwmon.c
new file mode 100644
index 000000000000..b2f115b5d8eb
--- /dev/null
+++ b/drivers/hwmon/nct6694-hwmon.c
@@ -0,0 +1,947 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 HWMON driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/hwmon.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/*
+ * USB command module type for NCT6694 report channel
+ * This defines the module type used for communication with the NCT6694
+ * report channel over the USB interface.
+ */
+#define NCT6694_RPT_MOD			0xFF
+
+/* Report channel */
+/*
+ * The report channel is used to report the status of the hardware monitor
+ * devices, such as voltage, temperature, fan speed, and PWM.
+ */
+#define NCT6694_VIN_IDX(x)		(0x00 + (x))
+#define NCT6694_TIN_IDX(x)			\
+	({ typeof(x) (_x) = (x);		\
+	 ((_x) < 10) ? (0x10 + ((_x) * 2)) :	\
+	 (0x30 + (((_x) - 10) * 2)); })
+#define NCT6694_FIN_IDX(x)		(0x50 + ((x) * 2))
+#define NCT6694_PWM_IDX(x)		(0x70 + (x))
+#define NCT6694_VIN_STS(x)		(0x68 + (x))
+#define NCT6694_TIN_STS(x)		(0x6A + (x))
+#define NCT6694_FIN_STS(x)		(0x6E + (x))
+
+/*
+ * USB command module type for NCT6694 HWMON controller.
+ * This defines the module type used for communication with the NCT6694
+ * HWMON controller over the USB interface.
+ */
+#define NCT6694_HWMON_MOD		0x00
+
+/* Command 00h - Hardware Monitor Control */
+#define NCT6694_HWMON_CONTROL		0x00
+#define NCT6694_HWMON_CONTROL_SEL	0x00
+
+/* Command 02h - Alarm Control */
+#define NCT6694_HWMON_ALARM		0x02
+#define NCT6694_HWMON_ALARM_SEL		0x00
+
+/*
+ * USB command module type for NCT6694 PWM controller.
+ * This defines the module type used for communication with the NCT6694
+ * PWM controller over the USB interface.
+ */
+#define NCT6694_PWM_MOD			0x01
+
+/* PWM Command - Manual Control */
+#define NCT6694_PWM_CONTROL		0x01
+#define NCT6694_PWM_CONTROL_SEL		0x00
+
+#define NCT6694_FREQ_FROM_REG(reg)	((reg) * 25000 / 255)
+#define NCT6694_FREQ_TO_REG(val)	\
+	(DIV_ROUND_CLOSEST(clamp_val((val), 100, 25000) * 255, 25000))
+
+#define NCT6694_LSB_REG_MASK		GENMASK(7, 5)
+#define NCT6694_TIN_HYST_MASK		GENMASK(7, 5)
+
+enum nct6694_hwmon_temp_mode {
+	NCT6694_HWMON_TWOTIME_IRQ = 0,
+	NCT6694_HWMON_ONETIME_IRQ,
+	NCT6694_HWMON_REALTIME_IRQ,
+	NCT6694_HWMON_COMPARE_IRQ,
+};
+
+struct __packed nct6694_hwmon_control {
+	u8 vin_en[2];
+	u8 tin_en[2];
+	u8 fin_en[2];
+	u8 pwm_en[2];
+	u8 reserved1[40];
+	u8 pwm_freq[10];
+	u8 reserved2[6];
+};
+
+struct __packed nct6694_hwmon_alarm {
+	u8 smi_ctrl;
+	u8 reserved1[15];
+	struct {
+		u8 hl;
+		u8 ll;
+	} vin_limit[16];
+	struct {
+		u8 hyst;
+		s8 hl;
+	} tin_cfg[32];
+	__be16 fin_ll[10];
+	u8 reserved2[4];
+};
+
+struct __packed nct6694_pwm_control {
+	u8 mal_en[2];
+	u8 mal_val[10];
+	u8 reserved[12];
+};
+
+union __packed nct6694_hwmon_rpt {
+	u8 vin;
+	struct {
+		u8 msb;
+		u8 lsb;
+	} tin;
+	__be16 fin;
+	u8 pwm;
+	u8 status;
+};
+
+union __packed nct6694_hwmon_msg {
+	struct nct6694_hwmon_alarm hwmon_alarm;
+	struct nct6694_pwm_control pwm_ctrl;
+};
+
+struct nct6694_hwmon_data {
+	struct nct6694 *nct6694;
+	struct mutex lock;
+	struct nct6694_hwmon_control hwmon_en;
+	union nct6694_hwmon_rpt *rpt;
+	union nct6694_hwmon_msg *msg;
+};
+
+static inline long in_from_reg(u8 reg)
+{
+	return reg * 16;
+}
+
+static inline u8 in_to_reg(long val)
+{
+	return DIV_ROUND_CLOSEST(val, 16);
+}
+
+static inline long temp_from_reg(s8 reg)
+{
+	return reg * 1000;
+}
+
+static inline s8 temp_to_reg(long val)
+{
+	return DIV_ROUND_CLOSEST(val, 1000);
+}
+
+#define NCT6694_HWMON_IN_CONFIG (HWMON_I_INPUT | HWMON_I_ENABLE |	\
+				 HWMON_I_MAX | HWMON_I_MIN |		\
+				 HWMON_I_ALARM)
+#define NCT6694_HWMON_TEMP_CONFIG (HWMON_T_INPUT | HWMON_T_ENABLE |	\
+				   HWMON_T_MAX | HWMON_T_MAX_HYST |	\
+				   HWMON_T_MAX_ALARM)
+#define NCT6694_HWMON_FAN_CONFIG (HWMON_F_INPUT | HWMON_F_ENABLE |	\
+				  HWMON_F_MIN | HWMON_F_MIN_ALARM)
+#define NCT6694_HWMON_PWM_CONFIG (HWMON_PWM_INPUT | HWMON_PWM_ENABLE |	\
+				  HWMON_PWM_FREQ)
+static const struct hwmon_channel_info *nct6694_info[] = {
+	HWMON_CHANNEL_INFO(in,
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN0 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN1 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN2 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN3 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN5 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN6 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN7 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN14 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN15 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VIN16 */
+			   NCT6694_HWMON_IN_CONFIG,	/* VBAT */
+			   NCT6694_HWMON_IN_CONFIG,	/* VSB */
+			   NCT6694_HWMON_IN_CONFIG,	/* AVSB */
+			   NCT6694_HWMON_IN_CONFIG,	/* VCC */
+			   NCT6694_HWMON_IN_CONFIG,	/* VHIF */
+			   NCT6694_HWMON_IN_CONFIG),	/* VTT */
+
+	HWMON_CHANNEL_INFO(temp,
+			   NCT6694_HWMON_TEMP_CONFIG,	/* THR1 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* THR2 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* THR14 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* THR15 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* THR16 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* TDP0 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* TDP1 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* TDP2 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* TDP3 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* TDP4 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN0 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN1 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN2 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN3 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN4 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN5 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN6 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN7 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN8 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN9 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN10 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN11 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN12 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN13 */
+			   NCT6694_HWMON_TEMP_CONFIG,	/* DTIN14 */
+			   NCT6694_HWMON_TEMP_CONFIG),	/* DTIN15 */
+
+	HWMON_CHANNEL_INFO(fan,
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN0 */
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN1 */
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN2 */
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN3 */
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN4 */
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN5 */
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN6 */
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN7 */
+			   NCT6694_HWMON_FAN_CONFIG,	/* FIN8 */
+			   NCT6694_HWMON_FAN_CONFIG),	/* FIN9 */
+
+	HWMON_CHANNEL_INFO(pwm,
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM0 */
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM1 */
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM2 */
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM3 */
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM4 */
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM5 */
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM6 */
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM7 */
+			   NCT6694_HWMON_PWM_CONFIG,	/* PWM8 */
+			   NCT6694_HWMON_PWM_CONFIG),	/* PWM9 */
+	NULL
+};
+
+static int nct6694_in_read(struct device *dev, u32 attr, int channel,
+			   long *val)
+{
+	struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+	struct nct6694_cmd_header cmd_hd;
+	unsigned char vin_en;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	switch (attr) {
+	case hwmon_in_enable:
+		vin_en = data->hwmon_en.vin_en[(channel / 8)];
+		*val = !!(vin_en & BIT(channel % 8));
+
+		return 0;
+	case hwmon_in_input:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_RPT_MOD,
+			.offset = cpu_to_le16(NCT6694_VIN_IDX(channel)),
+			.len = cpu_to_le16(sizeof(data->rpt->vin))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->rpt->vin);
+		if (ret)
+			return ret;
+
+		*val = in_from_reg(data->rpt->vin);
+
+		return 0;
+	case hwmon_in_max:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		*val = in_from_reg(data->msg->hwmon_alarm.vin_limit[channel].hl);
+
+		return 0;
+	case hwmon_in_min:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		*val = in_from_reg(data->msg->hwmon_alarm.vin_limit[channel].ll);
+
+		return 0;
+	case hwmon_in_alarm:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_RPT_MOD,
+			.offset = cpu_to_le16(NCT6694_VIN_STS(channel / 8)),
+			.len = cpu_to_le16(sizeof(data->rpt->status))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->rpt->status);
+		if (ret)
+			return ret;
+
+		*val = !!(data->rpt->status & BIT(channel % 8));
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_temp_read(struct device *dev, u32 attr, int channel,
+			     long *val)
+{
+	struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+	struct nct6694_cmd_header cmd_hd;
+	unsigned char temp_en, temp_hyst;
+	signed char temp_max;
+	int ret, temp_raw;
+
+	guard(mutex)(&data->lock);
+
+	switch (attr) {
+	case hwmon_temp_enable:
+		temp_en = data->hwmon_en.tin_en[channel / 8];
+		*val = !!(temp_en & BIT(channel % 8));
+
+		return 0;
+	case hwmon_temp_input:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_RPT_MOD,
+			.offset = cpu_to_le16(NCT6694_TIN_IDX(channel)),
+			.len = cpu_to_le16(sizeof(data->rpt->tin))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->rpt->tin);
+		if (ret)
+			return ret;
+
+		temp_raw = data->rpt->tin.msb << 3;
+		temp_raw |= FIELD_GET(NCT6694_LSB_REG_MASK, data->rpt->tin.lsb);
+
+		/* Real temperature(milli degrees Celsius) = temp_raw * 1000 * 0.125 */
+		*val = sign_extend32(temp_raw, 10) * 125;
+
+		return 0;
+	case hwmon_temp_max:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		*val = temp_from_reg(data->msg->hwmon_alarm.tin_cfg[channel].hl);
+
+		return 0;
+	case hwmon_temp_max_hyst:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		temp_max = data->msg->hwmon_alarm.tin_cfg[channel].hl;
+		temp_hyst = FIELD_GET(NCT6694_TIN_HYST_MASK,
+				      data->msg->hwmon_alarm.tin_cfg[channel].hyst);
+		*val = temp_from_reg(temp_max - temp_hyst);
+
+		return 0;
+	case hwmon_temp_max_alarm:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_RPT_MOD,
+			.offset = cpu_to_le16(NCT6694_TIN_STS(channel / 8)),
+			.len = cpu_to_le16(sizeof(data->rpt->status))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->rpt->status);
+		if (ret)
+			return ret;
+
+		*val = !!(data->rpt->status & BIT(channel % 8));
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_fan_read(struct device *dev, u32 attr, int channel,
+			    long *val)
+{
+	struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+	struct nct6694_cmd_header cmd_hd;
+	unsigned char fanin_en;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	switch (attr) {
+	case hwmon_fan_enable:
+		fanin_en = data->hwmon_en.fin_en[channel / 8];
+		*val = !!(fanin_en & BIT(channel % 8));
+
+		return 0;
+	case hwmon_fan_input:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_RPT_MOD,
+			.offset = cpu_to_le16(NCT6694_FIN_IDX(channel)),
+			.len = cpu_to_le16(sizeof(data->rpt->fin))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->rpt->fin);
+		if (ret)
+			return ret;
+
+		*val = be16_to_cpu(data->rpt->fin);
+
+		return 0;
+	case hwmon_fan_min:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		*val = be16_to_cpu(data->msg->hwmon_alarm.fin_ll[channel]);
+
+		return 0;
+	case hwmon_fan_min_alarm:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_RPT_MOD,
+			.offset = cpu_to_le16(NCT6694_FIN_STS(channel / 8)),
+			.len = cpu_to_le16(sizeof(data->rpt->status))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->rpt->status);
+		if (ret)
+			return ret;
+
+		*val = !!(data->rpt->status & BIT(channel % 8));
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_pwm_read(struct device *dev, u32 attr, int channel,
+			    long *val)
+{
+	struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+	struct nct6694_cmd_header cmd_hd;
+	unsigned char pwm_en;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	switch (attr) {
+	case hwmon_pwm_enable:
+		pwm_en = data->hwmon_en.pwm_en[channel / 8];
+		*val = !!(pwm_en & BIT(channel % 8));
+
+		return 0;
+	case hwmon_pwm_input:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_RPT_MOD,
+			.offset = cpu_to_le16(NCT6694_PWM_IDX(channel)),
+			.len = cpu_to_le16(sizeof(data->rpt->pwm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->rpt->pwm);
+		if (ret)
+			return ret;
+
+		*val = data->rpt->pwm;
+
+		return 0;
+	case hwmon_pwm_freq:
+		*val = NCT6694_FREQ_FROM_REG(data->hwmon_en.pwm_freq[channel]);
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_in_write(struct device *dev, u32 attr, int channel,
+			    long val)
+{
+	struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+	struct nct6694_cmd_header cmd_hd;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	switch (attr) {
+	case hwmon_in_enable:
+		if (val == 0)
+			data->hwmon_en.vin_en[channel / 8] &= ~BIT(channel % 8);
+		else if (val == 1)
+			data->hwmon_en.vin_en[channel / 8] |= BIT(channel % 8);
+		else
+			return -EINVAL;
+
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_CONTROL,
+			.sel = NCT6694_HWMON_CONTROL_SEL,
+			.len = cpu_to_le16(sizeof(data->hwmon_en))
+		};
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->hwmon_en);
+	case hwmon_in_max:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		val = clamp_val(val, 0, 2032);
+		data->msg->hwmon_alarm.vin_limit[channel].hl = in_to_reg(val);
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->msg->hwmon_alarm);
+	case hwmon_in_min:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		val = clamp_val(val, 0, 2032);
+		data->msg->hwmon_alarm.vin_limit[channel].ll = in_to_reg(val);
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->msg->hwmon_alarm);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_temp_write(struct device *dev, u32 attr, int channel,
+			      long val)
+{
+	struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+	struct nct6694_cmd_header cmd_hd;
+	unsigned char temp_hyst;
+	signed char temp_max;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	switch (attr) {
+	case hwmon_temp_enable:
+		if (val == 0)
+			data->hwmon_en.tin_en[channel / 8] &= ~BIT(channel % 8);
+		else if (val == 1)
+			data->hwmon_en.tin_en[channel / 8] |= BIT(channel % 8);
+		else
+			return -EINVAL;
+
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_CONTROL,
+			.sel = NCT6694_HWMON_CONTROL_SEL,
+			.len = cpu_to_le16(sizeof(data->hwmon_en))
+		};
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->hwmon_en);
+	case hwmon_temp_max:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		val = clamp_val(val, -127000, 127000);
+		data->msg->hwmon_alarm.tin_cfg[channel].hl = temp_to_reg(val);
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->msg->hwmon_alarm);
+	case hwmon_temp_max_hyst:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+
+		val = clamp_val(val, -127000, 127000);
+		temp_max = data->msg->hwmon_alarm.tin_cfg[channel].hl;
+		temp_hyst = temp_max - temp_to_reg(val);
+		temp_hyst = clamp_val(temp_hyst, 0, 7);
+		data->msg->hwmon_alarm.tin_cfg[channel].hyst =
+			(data->msg->hwmon_alarm.tin_cfg[channel].hyst & ~NCT6694_TIN_HYST_MASK) |
+			FIELD_PREP(NCT6694_TIN_HYST_MASK, temp_hyst);
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->msg->hwmon_alarm);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_fan_write(struct device *dev, u32 attr, int channel,
+			     long val)
+{
+	struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+	struct nct6694_cmd_header cmd_hd;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	switch (attr) {
+	case hwmon_fan_enable:
+		if (val == 0)
+			data->hwmon_en.fin_en[channel / 8] &= ~BIT(channel % 8);
+		else if (val == 1)
+			data->hwmon_en.fin_en[channel / 8] |= BIT(channel % 8);
+		else
+			return -EINVAL;
+
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_CONTROL,
+			.sel = NCT6694_HWMON_CONTROL_SEL,
+			.len = cpu_to_le16(sizeof(data->hwmon_en))
+		};
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->hwmon_en);
+	case hwmon_fan_min:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_ALARM,
+			.sel = NCT6694_HWMON_ALARM_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+		};
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->hwmon_alarm);
+		if (ret)
+			return ret;
+
+		val = clamp_val(val, 1, 65535);
+		data->msg->hwmon_alarm.fin_ll[channel] = cpu_to_be16(val);
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->msg->hwmon_alarm);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_pwm_write(struct device *dev, u32 attr, int channel,
+			     long val)
+{
+	struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+	struct nct6694_cmd_header cmd_hd;
+	int ret;
+
+	guard(mutex)(&data->lock);
+
+	switch (attr) {
+	case hwmon_pwm_enable:
+		if (val == 0)
+			data->hwmon_en.pwm_en[channel / 8] &= ~BIT(channel % 8);
+		else if (val == 1)
+			data->hwmon_en.pwm_en[channel / 8] |= BIT(channel % 8);
+		else
+			return -EINVAL;
+
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_CONTROL,
+			.sel = NCT6694_HWMON_CONTROL_SEL,
+			.len = cpu_to_le16(sizeof(data->hwmon_en))
+		};
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->hwmon_en);
+	case hwmon_pwm_input:
+		if (val < 0 || val > 255)
+			return -EINVAL;
+
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_PWM_MOD,
+			.cmd = NCT6694_PWM_CONTROL,
+			.sel = NCT6694_PWM_CONTROL_SEL,
+			.len = cpu_to_le16(sizeof(data->msg->pwm_ctrl))
+		};
+
+		ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+				       &data->msg->pwm_ctrl);
+		if (ret)
+			return ret;
+
+		data->msg->pwm_ctrl.mal_val[channel] = val;
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->msg->pwm_ctrl);
+	case hwmon_pwm_freq:
+		cmd_hd = (struct nct6694_cmd_header) {
+			.mod = NCT6694_HWMON_MOD,
+			.cmd = NCT6694_HWMON_CONTROL,
+			.sel = NCT6694_HWMON_CONTROL_SEL,
+			.len = cpu_to_le16(sizeof(data->hwmon_en))
+		};
+
+		data->hwmon_en.pwm_freq[channel] = NCT6694_FREQ_TO_REG(val);
+
+		return nct6694_write_msg(data->nct6694, &cmd_hd,
+					 &data->hwmon_en);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_in:
+		/* in mV */
+		return nct6694_in_read(dev, attr, channel, val);
+	case hwmon_temp:
+		/* in mC */
+		return nct6694_temp_read(dev, attr, channel, val);
+	case hwmon_fan:
+		/* in RPM */
+		return nct6694_fan_read(dev, attr, channel, val);
+	case hwmon_pwm:
+		/* in value 0~255 */
+		return nct6694_pwm_read(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nct6694_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_in:
+		return nct6694_in_write(dev, attr, channel, val);
+	case hwmon_temp:
+		return nct6694_temp_write(dev, attr, channel, val);
+	case hwmon_fan:
+		return nct6694_fan_write(dev, attr, channel, val);
+	case hwmon_pwm:
+		return nct6694_pwm_write(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t nct6694_is_visible(const void *data,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_in:
+		switch (attr) {
+		case hwmon_in_enable:
+		case hwmon_in_max:
+		case hwmon_in_min:
+			return 0644;
+		case hwmon_in_alarm:
+		case hwmon_in_input:
+			return 0444;
+		default:
+			return 0;
+		}
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_enable:
+		case hwmon_temp_max:
+		case hwmon_temp_max_hyst:
+			return 0644;
+		case hwmon_temp_input:
+		case hwmon_temp_max_alarm:
+			return 0444;
+		default:
+			return 0;
+		}
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_enable:
+		case hwmon_fan_min:
+			return 0644;
+		case hwmon_fan_input:
+		case hwmon_fan_min_alarm:
+			return 0444;
+		default:
+			return 0;
+		}
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_enable:
+		case hwmon_pwm_freq:
+		case hwmon_pwm_input:
+			return 0644;
+		default:
+			return 0;
+		}
+	default:
+		return 0;
+	}
+}
+
+static const struct hwmon_ops nct6694_hwmon_ops = {
+	.is_visible = nct6694_is_visible,
+	.read = nct6694_read,
+	.write = nct6694_write,
+};
+
+static const struct hwmon_chip_info nct6694_chip_info = {
+	.ops = &nct6694_hwmon_ops,
+	.info = nct6694_info,
+};
+
+static int nct6694_hwmon_init(struct nct6694_hwmon_data *data)
+{
+	struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_HWMON_MOD,
+		.cmd = NCT6694_HWMON_CONTROL,
+		.sel = NCT6694_HWMON_CONTROL_SEL,
+		.len = cpu_to_le16(sizeof(data->hwmon_en))
+	};
+	int ret;
+
+	/*
+	 * Record each Hardware Monitor Channel enable status
+	 * and PWM frequency register
+	 */
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+			       &data->hwmon_en);
+	if (ret)
+		return ret;
+
+	cmd_hd = (struct nct6694_cmd_header) {
+		.mod = NCT6694_HWMON_MOD,
+		.cmd = NCT6694_HWMON_ALARM,
+		.sel = NCT6694_HWMON_ALARM_SEL,
+		.len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+	};
+
+	/* Select hwmon device alarm mode */
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+			       &data->msg->hwmon_alarm);
+	if (ret)
+		return ret;
+
+	data->msg->hwmon_alarm.smi_ctrl = NCT6694_HWMON_REALTIME_IRQ;
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd,
+				 &data->msg->hwmon_alarm);
+}
+
+static int nct6694_hwmon_probe(struct platform_device *pdev)
+{
+	struct nct6694_hwmon_data *data;
+	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+	struct device *hwmon_dev;
+	int ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->rpt = devm_kzalloc(&pdev->dev, sizeof(union nct6694_hwmon_rpt),
+				 GFP_KERNEL);
+	if (!data->rpt)
+		return -ENOMEM;
+
+	data->msg = devm_kzalloc(&pdev->dev, sizeof(union nct6694_hwmon_msg),
+				 GFP_KERNEL);
+	if (!data->msg)
+		return -ENOMEM;
+
+	data->nct6694 = nct6694;
+	devm_mutex_init(&pdev->dev, &data->lock);
+
+	ret = nct6694_hwmon_init(data);
+	if (ret)
+		return ret;
+
+	/* Register hwmon device to HWMON framework */
+	hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
+							 "nct6694", data,
+							 &nct6694_chip_info,
+							 NULL);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static struct platform_driver nct6694_hwmon_driver = {
+	.driver = {
+		.name	= "nct6694-hwmon",
+	},
+	.probe		= nct6694_hwmon_probe,
+};
+
+module_platform_driver(nct6694_hwmon_driver);
+
+MODULE_DESCRIPTION("USB-HWMON driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-hwmon");
-- 
2.34.1

[PATCH v7 7/7] rtc: Add Nuvoton NCT6694 RTC support

[Ming Yu]

This driver supports RTC functionality for NCT6694 MFD device
based on USB interface.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
 MAINTAINERS               |   1 +
 drivers/rtc/Kconfig       |  10 ++
 drivers/rtc/Makefile      |   1 +
 drivers/rtc/rtc-nct6694.c | 286 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 298 insertions(+)
 create mode 100644 drivers/rtc/rtc-nct6694.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a9eda4530b07..7eba4ffdc877 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16927,6 +16927,7 @@ F:	drivers/hwmon/nct6694-hwmon.c
 F:	drivers/i2c/busses/i2c-nct6694.c
 F:	drivers/mfd/nct6694.c
 F:	drivers/net/can/usb/nct6694_canfd.c
+F:	drivers/rtc/rtc-nct6694.c
 F:	drivers/watchdog/nct6694_wdt.c
 F:	include/linux/mfd/nct6694.h
 
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 0bbbf778ecfa..248425bf26f3 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -416,6 +416,16 @@ config RTC_DRV_NCT3018Y
 	   This driver can also be built as a module, if so, the module will be
 	   called "rtc-nct3018y".
 
+config RTC_DRV_NCT6694
+	tristate "Nuvoton NCT6694 RTC support"
+	depends on MFD_NCT6694
+	help
+	  If you say yes to this option, support will be included for Nuvoton
+	  NCT6694, a USB device to RTC.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called rtc-nct6694.
+
 config RTC_DRV_RK808
 	tristate "Rockchip RK805/RK808/RK809/RK817/RK818 RTC"
 	depends on MFD_RK8XX
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 489b4ab07068..d0d6f4a4972e 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -118,6 +118,7 @@ obj-$(CONFIG_RTC_DRV_MXC)	+= rtc-mxc.o
 obj-$(CONFIG_RTC_DRV_MXC_V2)	+= rtc-mxc_v2.o
 obj-$(CONFIG_RTC_DRV_GAMECUBE)	+= rtc-gamecube.o
 obj-$(CONFIG_RTC_DRV_NCT3018Y)	+= rtc-nct3018y.o
+obj-$(CONFIG_RTC_DRV_NCT6694)	+= rtc-nct6694.o
 obj-$(CONFIG_RTC_DRV_NTXEC)	+= rtc-ntxec.o
 obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o
 obj-$(CONFIG_RTC_DRV_OPAL)	+= rtc-opal.o
diff --git a/drivers/rtc/rtc-nct6694.c b/drivers/rtc/rtc-nct6694.c
new file mode 100644
index 000000000000..892674d453d1
--- /dev/null
+++ b/drivers/rtc/rtc-nct6694.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 RTC driver based on USB interface.
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+
+#include <linux/bcd.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+/*
+ * USB command module type for NCT6694 RTC controller.
+ * This defines the module type used for communication with the NCT6694
+ * RTC controller over the USB interface.
+ */
+#define NCT6694_RTC_MOD		0x08
+
+/* Command 00h - RTC Time */
+#define NCT6694_RTC_TIME	0x0000
+#define NCT6694_RTC_TIME_SEL	0x00
+
+/* Command 01h - RTC Alarm */
+#define NCT6694_RTC_ALARM	0x01
+#define NCT6694_RTC_ALARM_SEL	0x00
+
+/* Command 02h - RTC Status */
+#define NCT6694_RTC_STATUS	0x02
+#define NCT6694_RTC_STATUS_SEL	0x00
+
+#define NCT6694_RTC_IRQ_INT_EN	BIT(0)	/* Transmit a USB INT-in when RTC alarm */
+#define NCT6694_RTC_IRQ_GPO_EN	BIT(5)	/* Trigger a GPO Low Pulse when RTC alarm */
+
+#define NCT6694_RTC_IRQ_EN	(NCT6694_RTC_IRQ_INT_EN | NCT6694_RTC_IRQ_GPO_EN)
+#define NCT6694_RTC_IRQ_STS	BIT(0)	/* Write 1 clear IRQ status */
+
+struct __packed nct6694_rtc_time {
+	u8 sec;
+	u8 min;
+	u8 hour;
+	u8 week;
+	u8 day;
+	u8 month;
+	u8 year;
+};
+
+struct __packed nct6694_rtc_alarm {
+	u8 sec;
+	u8 min;
+	u8 hour;
+	u8 alarm_en;
+	u8 alarm_pend;
+};
+
+struct __packed nct6694_rtc_status {
+	u8 irq_en;
+	u8 irq_pend;
+};
+
+union __packed nct6694_rtc_msg {
+	struct nct6694_rtc_time time;
+	struct nct6694_rtc_alarm alarm;
+	struct nct6694_rtc_status sts;
+};
+
+struct nct6694_rtc_data {
+	struct nct6694 *nct6694;
+	struct rtc_device *rtc;
+	union nct6694_rtc_msg *msg;
+};
+
+static int nct6694_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
+	struct nct6694_rtc_time *time = &data->msg->time;
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_RTC_MOD,
+		.cmd = NCT6694_RTC_TIME,
+		.sel = NCT6694_RTC_TIME_SEL,
+		.len = cpu_to_le16(sizeof(*time))
+	};
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, time);
+	if (ret)
+		return ret;
+
+	tm->tm_sec = bcd2bin(time->sec);		/* tm_sec expect 0 ~ 59 */
+	tm->tm_min = bcd2bin(time->min);		/* tm_min expect 0 ~ 59 */
+	tm->tm_hour = bcd2bin(time->hour);		/* tm_hour expect 0 ~ 23 */
+	tm->tm_wday = bcd2bin(time->week) - 1;		/* tm_wday expect 0 ~ 6 */
+	tm->tm_mday = bcd2bin(time->day);		/* tm_mday expect 1 ~ 31 */
+	tm->tm_mon = bcd2bin(time->month) - 1;		/* tm_month expect 0 ~ 11 */
+	tm->tm_year = bcd2bin(time->year) + 100;	/* tm_year expect since 1900 */
+
+	return ret;
+}
+
+static int nct6694_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
+	struct nct6694_rtc_time *time = &data->msg->time;
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_RTC_MOD,
+		.cmd = NCT6694_RTC_TIME,
+		.sel = NCT6694_RTC_TIME_SEL,
+		.len = cpu_to_le16(sizeof(*time))
+	};
+
+	time->sec = bin2bcd(tm->tm_sec);
+	time->min = bin2bcd(tm->tm_min);
+	time->hour = bin2bcd(tm->tm_hour);
+	time->week = bin2bcd(tm->tm_wday + 1);
+	time->day = bin2bcd(tm->tm_mday);
+	time->month = bin2bcd(tm->tm_mon + 1);
+	time->year = bin2bcd(tm->tm_year - 100);
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, time);
+}
+
+static int nct6694_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
+	struct nct6694_rtc_alarm *alarm = &data->msg->alarm;
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_RTC_MOD,
+		.cmd = NCT6694_RTC_ALARM,
+		.sel = NCT6694_RTC_ALARM_SEL,
+		.len = cpu_to_le16(sizeof(*alarm))
+	};
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, alarm);
+	if (ret)
+		return ret;
+
+	alrm->time.tm_sec = bcd2bin(alarm->sec);
+	alrm->time.tm_min = bcd2bin(alarm->min);
+	alrm->time.tm_hour = bcd2bin(alarm->hour);
+	alrm->enabled = alarm->alarm_en;
+	alrm->pending = alarm->alarm_pend;
+
+	return ret;
+}
+
+static int nct6694_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
+	struct nct6694_rtc_alarm *alarm = &data->msg->alarm;
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_RTC_MOD,
+		.cmd = NCT6694_RTC_ALARM,
+		.sel = NCT6694_RTC_ALARM_SEL,
+		.len = cpu_to_le16(sizeof(*alarm))
+	};
+
+	alarm->sec = bin2bcd(alrm->time.tm_sec);
+	alarm->min = bin2bcd(alrm->time.tm_min);
+	alarm->hour = bin2bcd(alrm->time.tm_hour);
+	alarm->alarm_en = alrm->enabled ? NCT6694_RTC_IRQ_EN : 0;
+	alarm->alarm_pend = 0;
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, alarm);
+}
+
+static int nct6694_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
+	struct nct6694_rtc_status *sts = &data->msg->sts;
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_RTC_MOD,
+		.cmd = NCT6694_RTC_STATUS,
+		.sel = NCT6694_RTC_STATUS_SEL,
+		.len = cpu_to_le16(sizeof(*sts))
+	};
+
+	if (enabled)
+		sts->irq_en |= NCT6694_RTC_IRQ_EN;
+	else
+		sts->irq_en &= ~NCT6694_RTC_IRQ_EN;
+
+	sts->irq_pend = 0;
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, sts);
+}
+
+static const struct rtc_class_ops nct6694_rtc_ops = {
+	.read_time = nct6694_rtc_read_time,
+	.set_time = nct6694_rtc_set_time,
+	.read_alarm = nct6694_rtc_read_alarm,
+	.set_alarm = nct6694_rtc_set_alarm,
+	.alarm_irq_enable = nct6694_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t nct6694_irq(int irq, void *dev_id)
+{
+	struct nct6694_rtc_data *data = dev_id;
+	struct nct6694_rtc_status *sts = &data->msg->sts;
+	static const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_RTC_MOD,
+		.cmd = NCT6694_RTC_STATUS,
+		.sel = NCT6694_RTC_STATUS_SEL,
+		.len = cpu_to_le16(sizeof(*sts))
+	};
+	int ret;
+
+	rtc_lock(data->rtc);
+
+	sts->irq_en = NCT6694_RTC_IRQ_EN;
+	sts->irq_pend = NCT6694_RTC_IRQ_STS;
+	ret = nct6694_write_msg(data->nct6694, &cmd_hd, sts);
+	if (ret) {
+		rtc_unlock(data->rtc);
+		return IRQ_NONE;
+	}
+
+	rtc_update_irq(data->rtc, 1, RTC_IRQF | RTC_AF);
+
+	rtc_unlock(data->rtc);
+
+	return IRQ_HANDLED;
+}
+
+static int nct6694_rtc_probe(struct platform_device *pdev)
+{
+	struct nct6694_rtc_data *data;
+	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
+	int ret, irq;
+
+	irq = irq_create_mapping(nct6694->domain, NCT6694_IRQ_RTC);
+	if (!irq)
+		return -EINVAL;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->msg = devm_kzalloc(&pdev->dev, sizeof(union nct6694_rtc_msg),
+				 GFP_KERNEL);
+	if (!data->msg)
+		return -ENOMEM;
+
+	data->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(data->rtc))
+		return PTR_ERR(data->rtc);
+
+	data->nct6694 = nct6694;
+	data->rtc->ops = &nct6694_rtc_ops;
+	data->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	data->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+	platform_set_drvdata(pdev, data);
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+					nct6694_irq, IRQF_ONESHOT,
+					"rtc-nct6694", data);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret, "Failed to request irq\n");
+
+	ret = devm_rtc_register_device(data->rtc);
+	if (ret)
+		return ret;
+
+	device_init_wakeup(&pdev->dev, true);
+	return 0;
+}
+
+static struct platform_driver nct6694_rtc_driver = {
+	.driver = {
+		.name	= "rtc-nct6694",
+	},
+	.probe		= nct6694_rtc_probe,
+};
+
+module_platform_driver(nct6694_rtc_driver);
+
+MODULE_DESCRIPTION("USB-RTC driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-rtc");
-- 
2.34.1

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Marc Kleine-Budde]

[-- Attachment #1: Type: text/plain, Size: 28282 bytes --]

On 07.02.2025 15:44:59, Ming Yu wrote:
> This driver supports Socket CANFD functionality for NCT6694 MFD
> device based on USB interface.
> 
> Signed-off-by: Ming Yu <a0282524688@gmail.com>
> ---
>  MAINTAINERS                         |   1 +
>  drivers/net/can/usb/Kconfig         |  11 +
>  drivers/net/can/usb/Makefile        |   1 +
>  drivers/net/can/usb/nct6694_canfd.c | 809 ++++++++++++++++++++++++++++
>  4 files changed, 822 insertions(+)
>  create mode 100644 drivers/net/can/usb/nct6694_canfd.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 1327e7a6e507..8aa611504172 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16925,6 +16925,7 @@ S:	Supported
>  F:	drivers/gpio/gpio-nct6694.c
>  F:	drivers/i2c/busses/i2c-nct6694.c
>  F:	drivers/mfd/nct6694.c
> +F:	drivers/net/can/usb/nct6694_canfd.c
>  F:	include/linux/mfd/nct6694.h
>  
>  NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVER
> diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
> index 9dae0c71a2e1..759e724a67cf 100644
> --- a/drivers/net/can/usb/Kconfig
> +++ b/drivers/net/can/usb/Kconfig
> @@ -133,6 +133,17 @@ config CAN_MCBA_USB
>  	  This driver supports the CAN BUS Analyzer interface
>  	  from Microchip (http://www.microchip.com/development-tools/).
>  
> +config CAN_NCT6694
> +	tristate "Nuvoton NCT6694 Socket CANfd support"
> +	depends on MFD_NCT6694
> +	select CAN_RX_OFFLOAD
> +	help
> +	  If you say yes to this option, support will be included for Nuvoton
> +	  NCT6694, a USB device to socket CANfd controller.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called nct6694_canfd.
> +
>  config CAN_PEAK_USB
>  	tristate "PEAK PCAN-USB/USB Pro interfaces for CAN 2.0b/CAN-FD"
>  	help
> diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
> index 8b11088e9a59..fcafb1ac262e 100644
> --- a/drivers/net/can/usb/Makefile
> +++ b/drivers/net/can/usb/Makefile
> @@ -11,5 +11,6 @@ obj-$(CONFIG_CAN_F81604) += f81604.o
>  obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
>  obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb/
>  obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o
> +obj-$(CONFIG_CAN_NCT6694) += nct6694_canfd.o
>  obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
>  obj-$(CONFIG_CAN_UCAN) += ucan.o
> diff --git a/drivers/net/can/usb/nct6694_canfd.c b/drivers/net/can/usb/nct6694_canfd.c
> new file mode 100644
> index 000000000000..a7527020ff71
> --- /dev/null
> +++ b/drivers/net/can/usb/nct6694_canfd.c
> @@ -0,0 +1,809 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Nuvoton NCT6694 Socket CANfd driver based on USB interface.
> + *
> + * Copyright (C) 2024 Nuvoton Technology Corp.
> + */

/* net-dev style multiline
 * comments look like this
 */

> +
> +#include <linux/can/dev.h>
> +#include <linux/can/rx-offload.h>
> +#include <linux/ethtool.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/nct6694.h>
> +#include <linux/module.h>
> +#include <linux/netdevice.h>
> +#include <linux/platform_device.h>
> +
> +#define DRVNAME "nct6694_canfd"
> +
> +/*
> + * USB command module type for NCT6694 CANfd controller.
> + * This defines the module type used for communication with the NCT6694
> + * CANfd controller over the USB interface.
> + */

/* net-dev style multiline
 * comments look like this
 */

or remove the comment altogether as it's stating the obvious :)

> +#define NCT6694_CAN_MOD			0x05
> +
> +/* Command 00h - CAN Setting and Initialization */
> +#define NCT6694_CAN_SETTING		0x00
> +#define NCT6694_CAN_SETTING_CTRL1_MON	BIT(0)
> +#define NCT6694_CAN_SETTING_CTRL1_NISO	BIT(1)
> +#define NCT6694_CAN_SETTING_CTRL1_LBCK	BIT(2)
> +
> +/* Command 01h - CAN Information */
> +#define NCT6694_CAN_INFORMATION		0x01
> +#define NCT6694_CAN_INFORMATION_SEL	0x00
> +
> +/* Command 02h - CAN Event */
> +#define NCT6694_CAN_EVENT		0x02
> +#define NCT6694_CAN_EVENT_SEL(idx, mask)	\
> +	((idx ? 0x80 : 0x00) | ((mask) & 0x7F))
> +
> +#define NCT6694_CAN_EVENT_MASK		GENMASK(5, 0)
> +#define NCT6694_CAN_EVT_TX_FIFO_EMPTY	BIT(7)	/* Read-clear */
> +#define NCT6694_CAN_EVT_RX_DATA_LOST	BIT(5)	/* Read-clear */
> +#define NCT6694_CAN_EVT_RX_DATA_IN	BIT(7)	/* Read-clear*/
> +
> +/* Command 10h - CAN Deliver */
> +#define NCT6694_CAN_DELIVER		0x10
> +#define NCT6694_CAN_DELIVER_SEL(buf_cnt)	\
> +	((buf_cnt) & 0xFF)
> +
> +/* Command 11h - CAN Receive */
> +#define NCT6694_CAN_RECEIVE		0x11
> +#define NCT6694_CAN_RECEIVE_SEL(idx, buf_cnt)	\
> +	((idx ? 0x80 : 0x00) | ((buf_cnt) & 0x7F))
> +
> +#define NCT6694_CAN_FRAME_TAG_CAN0	0xC0
> +#define NCT6694_CAN_FRAME_TAG_CAN1	0xC1

in "include/linux/mfd/nct6694.h" it's CAN1 and CAN2, can you make it "0"
based everywhere?

what about making it:

#define NCT6694_CAN_FRAME_TAG_CAN(idx)  (0xC0 | (idx))

> +#define NCT6694_CAN_FRAME_FLAG_EFF	BIT(0)
> +#define NCT6694_CAN_FRAME_FLAG_RTR	BIT(1)
> +#define NCT6694_CAN_FRAME_FLAG_FD	BIT(2)
> +#define NCT6694_CAN_FRAME_FLAG_BRS	BIT(3)
> +#define NCT6694_CAN_FRAME_FLAG_ERR	BIT(4)
> +
> +#define NCT6694_NAPI_WEIGHT		32
> +
> +enum nct6694_event_err {
> +	NCT6694_CAN_EVT_ERR_NO_ERROR = 0,
> +	NCT6694_CAN_EVT_ERR_CRC_ERROR,
> +	NCT6694_CAN_EVT_ERR_STUFF_ERROR,
> +	NCT6694_CAN_EVT_ERR_ACK_ERROR,
> +	NCT6694_CAN_EVT_ERR_FORM_ERROR,
> +	NCT6694_CAN_EVT_ERR_BIT_ERROR,
> +	NCT6694_CAN_EVT_ERR_TIMEOUT_ERROR,
> +	NCT6694_CAN_EVT_ERR_UNKNOWN_ERROR,
> +};
> +
> +enum nct6694_event_status {
> +	NCT6694_CAN_EVT_STS_ERROR_ACTIVE = 0,
> +	NCT6694_CAN_EVT_STS_ERROR_PASSIVE,
> +	NCT6694_CAN_EVT_STS_BUS_OFF,
> +	NCT6694_CAN_EVT_STS_WARNING,
> +};
> +
> +struct __packed nct6694_can_setting {
> +	__le32 nbr;
> +	__le32 dbr;
> +	u8 active;
> +	u8 reserved[3];
> +	__le16 ctrl1;
> +	__le16 ctrl2;
> +	__le32 nbtp;
> +	__le32 dbtp;
> +};
> +
> +struct __packed nct6694_can_information {
> +	u8 tx_fifo_cnt;
> +	u8 rx_fifo_cnt;
> +	u8 reserved[2];
> +	__le32 can_clk;
> +};
> +
> +struct __packed nct6694_can_event {
> +	u8 err;
> +	u8 status;
> +	u8 tx_evt;
> +	u8 rx_evt;
> +	u8 rec;
> +	u8 tec;
> +	u8 reserved[2];
> +};
> +
> +struct __packed nct6694_can_frame {
> +	u8 tag;
> +	u8 flag;
> +	u8 reserved;
> +	u8 length;
> +	__le32 id;
> +	u8 data[CANFD_MAX_DLEN];
> +};
> +
> +struct nct6694_can_priv {
> +	struct can_priv can;	/* must be the first member */
> +	struct can_rx_offload offload;
> +	struct net_device *ndev;
> +	struct nct6694 *nct6694;
> +	struct workqueue_struct *wq;
> +	struct work_struct tx_work;
> +	struct nct6694_can_frame tx;
> +	struct nct6694_can_frame rx;
> +	struct nct6694_can_event event[2];
> +	struct can_berr_counter bec;
> +	unsigned char can_idx;

can you use ndev->dev_port instead?

> +};
> +
> +static inline struct nct6694_can_priv *rx_offload_to_priv(struct can_rx_offload *offload)
> +{
> +	return container_of(offload, struct nct6694_can_priv, offload);
> +}
> +
> +static const struct can_bittiming_const nct6694_can_bittiming_nominal_const = {
> +	.name = DRVNAME,
> +	.tseg1_min = 2,
> +	.tseg1_max = 256,
> +	.tseg2_min = 2,
> +	.tseg2_max = 128,
> +	.sjw_max = 128,
> +	.brp_min = 1,
> +	.brp_max = 511,
> +	.brp_inc = 1,
> +};
> +
> +static const struct can_bittiming_const nct6694_can_bittiming_data_const = {
> +	.name = DRVNAME,
> +	.tseg1_min = 1,
> +	.tseg1_max = 32,
> +	.tseg2_min = 1,
> +	.tseg2_max = 16,
> +	.sjw_max = 16,
> +	.brp_min = 1,
> +	.brp_max = 31,
> +	.brp_inc = 1,
> +};
> +
> +static void nct6694_can_rx_offload(struct can_rx_offload *offload,
> +				   struct sk_buff *skb)
> +{
> +	struct nct6694_can_priv *priv = rx_offload_to_priv(offload);
> +	int ret;
> +
> +	ret = can_rx_offload_queue_tail(offload, skb);
> +	if (ret)
> +		priv->ndev->stats.rx_fifo_errors++;
> +}
> +
> +static void nct6694_can_handle_lost_msg(struct net_device *ndev)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +	struct net_device_stats *stats = &ndev->stats;
> +	struct can_frame *cf;
> +	struct sk_buff *skb;
> +
> +	netdev_err(ndev, "RX FIFO overflow, message(s) lost.\n");
> +
> +	stats->rx_errors++;
> +	stats->rx_over_errors++;
> +
> +	skb = alloc_can_err_skb(ndev, &cf);
> +	if (!skb)
> +		return;
> +
> +	cf->can_id |= CAN_ERR_CRTL;
> +	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
> +
> +	nct6694_can_rx_offload(&priv->offload, skb);
> +}
> +
> +static void nct6694_can_rx(struct net_device *ndev, u8 rx_evt)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +	struct nct6694_can_frame *frame = &priv->rx;
> +	struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_CAN_MOD,
> +		.cmd = NCT6694_CAN_RECEIVE,
> +		.sel = NCT6694_CAN_RECEIVE_SEL(priv->can_idx, 1),
> +		.len = cpu_to_le16(sizeof(*frame))
> +	};
> +	struct sk_buff *skb;
> +	int ret;
> +
> +	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, frame);
> +	if (ret)
> +		return;
> +
> +	if (frame->flag & NCT6694_CAN_FRAME_FLAG_FD) {
> +		struct canfd_frame *cfd;
> +
> +		skb = alloc_canfd_skb(priv->ndev, &cfd);
> +		if (!skb)
> +			return;
> +
> +		cfd->can_id = le32_to_cpu(frame->id);
> +		cfd->len = canfd_sanitize_len(frame->length);
> +		if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
> +			cfd->can_id |= CAN_EFF_FLAG;
> +		if (frame->flag & NCT6694_CAN_FRAME_FLAG_BRS)
> +			cfd->flags |= CANFD_BRS;
> +		if (frame->flag & NCT6694_CAN_FRAME_FLAG_ERR)
> +			cfd->flags |= CANFD_ESI;
> +
> +		memcpy(cfd->data, frame->data, cfd->len);
> +	} else {
> +		struct can_frame *cf;
> +
> +		skb = alloc_can_skb(priv->ndev, &cf);
> +		if (!skb)
> +			return;
> +
> +		cf->can_id = le32_to_cpu(frame->id);
> +		cf->len = min_t(u8, frame->length, CAN_MAX_DLEN);

use can_cc_dlc2len()

> +		if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
> +			cf->can_id |= CAN_EFF_FLAG;
> +
> +		if (frame->flag & NCT6694_CAN_FRAME_FLAG_RTR)
> +			cf->can_id |= CAN_RTR_FLAG;
> +		else
> +			memcpy(cf->data, frame->data, cf->len);
> +	}
> +
> +	nct6694_can_rx_offload(&priv->offload, skb);
> +}
> +
> +static int nct6694_can_get_berr_counter(const struct net_device *ndev,
> +					struct can_berr_counter *bec)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +
> +	*bec = priv->bec;
> +
> +	return 0;
> +}
> +
> +static void nct6694_can_handle_state_change(struct net_device *ndev,
> +					    enum can_state new_state)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +	struct can_berr_counter bec;
> +	struct can_frame *cf;
> +	struct sk_buff *skb;
> +
> +	skb = alloc_can_err_skb(ndev, &cf);
> +
> +	nct6694_can_get_berr_counter(ndev, &bec);
> +
> +	switch (new_state) {
> +	case CAN_STATE_ERROR_ACTIVE:
> +		priv->can.can_stats.error_warning++;
                                    ^^^^^^^^^^^^^
> +		priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +		if (cf)
> +			cf->data[1] |= CAN_ERR_CRTL_ACTIVE;
> +		break;
> +	case CAN_STATE_ERROR_WARNING:
> +		priv->can.can_stats.error_warning++;
> +		priv->can.state = CAN_STATE_ERROR_WARNING;
> +		if (cf) {
> +			cf->can_id |= CAN_ERR_CRTL;
> +			if (bec.txerr > bec.rxerr)
> +				cf->data[1] = CAN_ERR_CRTL_TX_WARNING;
> +			else
> +				cf->data[1] = CAN_ERR_CRTL_RX_WARNING;
> +			cf->data[6] = bec.txerr;
> +			cf->data[7] = bec.rxerr;
> +		}
> +		break;
> +	case CAN_STATE_ERROR_PASSIVE:
> +		priv->can.can_stats.error_passive++;
> +		priv->can.state = CAN_STATE_ERROR_PASSIVE;
> +		if (cf) {
> +			cf->can_id |= CAN_ERR_CRTL;
> +			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
> +			if (bec.txerr >= CAN_ERROR_PASSIVE_THRESHOLD)
> +				cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
> +			cf->data[6] = bec.txerr;
> +			cf->data[7] = bec.rxerr;
> +		}
> +		break;
> +	case CAN_STATE_BUS_OFF:
> +		priv->can.state = CAN_STATE_BUS_OFF;
> +		priv->can.can_stats.bus_off++;
> +		if (cf)
> +			cf->can_id |= CAN_ERR_BUSOFF;
> +		can_free_echo_skb(ndev, 0, NULL);
> +		netif_stop_queue(ndev);
> +		can_bus_off(ndev);
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	nct6694_can_rx_offload(&priv->offload, skb);
> +}
> +
> +static void nct6694_can_handle_state_errors(struct net_device *ndev, u8 status)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);

It seems you don't have dedicated RX and TX states, so call
nct6694_can_get_berr_counter() and use can_state_get_by_berr_counter()
to get the states. Then basically do that what what
mcp251xfd_handle_cerrif() does, starting with "new_state = max(tx_state, rx_state);"

> +
> +	if (status == NCT6694_CAN_EVT_STS_ERROR_ACTIVE &&
> +	    priv->can.state != CAN_STATE_ERROR_ACTIVE) {
> +		netdev_dbg(ndev, "Error, entered active state\n");
> +		nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_ACTIVE);
> +	}
> +
> +	if (status == NCT6694_CAN_EVT_STS_WARNING &&
> +	    priv->can.state != CAN_STATE_ERROR_WARNING) {
> +		netdev_dbg(ndev, "Error, entered warning state\n");
> +		nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_WARNING);
> +	}
> +
> +	if (status == NCT6694_CAN_EVT_STS_ERROR_PASSIVE &&
> +	    priv->can.state != CAN_STATE_ERROR_PASSIVE) {
> +		netdev_dbg(ndev, "Error, entered passive state\n");
> +		nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_PASSIVE);
> +	}
> +
> +	if (status == NCT6694_CAN_EVT_STS_BUS_OFF &&
> +	    priv->can.state != CAN_STATE_BUS_OFF) {
> +		netdev_dbg(ndev, "Error, entered bus-off state\n");
> +		nct6694_can_handle_state_change(ndev, CAN_STATE_BUS_OFF);
> +	}
> +}
> +
> +static void nct6694_can_handle_bus_err(struct net_device *ndev, u8 bus_err)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +	struct can_frame *cf;
> +	struct sk_buff *skb;
> +
> +	if (bus_err == NCT6694_CAN_EVT_ERR_NO_ERROR)
> +		return;
> +
> +	priv->can.can_stats.bus_error++;
> +
> +	skb = alloc_can_err_skb(ndev, &cf);
> +	if (skb)
> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> +
> +	switch (bus_err) {
> +	case NCT6694_CAN_EVT_ERR_CRC_ERROR:
> +		netdev_dbg(ndev, "CRC error\n");
> +		ndev->stats.rx_errors++;
> +		if (skb)
> +			cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
> +		break;
> +
> +	case NCT6694_CAN_EVT_ERR_STUFF_ERROR:
> +		netdev_dbg(ndev, "Stuff error\n");
> +		ndev->stats.rx_errors++;
> +		if (skb)
> +			cf->data[2] |= CAN_ERR_PROT_STUFF;
> +		break;
> +
> +	case NCT6694_CAN_EVT_ERR_ACK_ERROR:
> +		netdev_dbg(ndev, "Ack error\n");
> +		ndev->stats.tx_errors++;
> +		if (skb) {
> +			cf->can_id |= CAN_ERR_ACK;
> +			cf->data[2] |= CAN_ERR_PROT_TX;
> +		}
> +		break;
> +
> +	case NCT6694_CAN_EVT_ERR_FORM_ERROR:
> +		netdev_dbg(ndev, "Form error\n");
> +		ndev->stats.rx_errors++;
> +		if (skb)
> +			cf->data[2] |= CAN_ERR_PROT_FORM;
> +		break;
> +
> +	case NCT6694_CAN_EVT_ERR_BIT_ERROR:
> +		netdev_dbg(ndev, "Bit error\n");
> +		ndev->stats.tx_errors++;
> +		if (skb)
> +			cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT;
> +		break;
> +
> +	default:
> +		break;
> +	}
> +

missing check:

        if (skb)

> +	nct6694_can_rx_offload(&priv->offload, skb);
> +}
> +
> +static void nct6694_can_tx_irq(struct net_device *ndev)
> +{
> +	struct net_device_stats *stats = &ndev->stats;
> +
> +	stats->tx_bytes += can_get_echo_skb(ndev, 0, NULL);

use can_rx_offload_get_echo_skb_queue_tail() here

> +	stats->tx_packets++;
> +	netif_wake_queue(ndev);
> +}
> +
> +static irqreturn_t nct6694_can_irq(int irq, void *data)
> +{
> +	struct net_device *ndev = data;
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +	struct nct6694_can_event *evt = priv->event;
> +	struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_CAN_MOD,
> +		.cmd = NCT6694_CAN_EVENT,
> +		.sel = NCT6694_CAN_EVENT_SEL(priv->can_idx, NCT6694_CAN_EVENT_MASK),
> +		.len = cpu_to_le16(sizeof(priv->event))
> +	};
> +	irqreturn_t handled = IRQ_NONE;
> +	int can_idx = priv->can_idx;
> +	int ret;

it would make sense to have a event pointer here instead of the can_idx?

        const struct nct6694_can_event *event = &priv->event[priv->can_idx];

> +
> +	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, evt);
> +	if (ret < 0)
> +		return handled;
> +
> +	if (priv->event[can_idx].rx_evt & NCT6694_CAN_EVT_RX_DATA_IN) {
> +		nct6694_can_rx(ndev, priv->event[can_idx].rx_evt);
> +		handled = IRQ_HANDLED;
> +	}
> +
> +	if (priv->event[can_idx].rx_evt & NCT6694_CAN_EVT_RX_DATA_LOST) {
> +		nct6694_can_handle_lost_msg(ndev);
> +		handled = IRQ_HANDLED;
> +	}
> +
> +	if (priv->event[can_idx].status) {
> +		nct6694_can_handle_state_errors(ndev, priv->event[can_idx].status);
> +		handled = IRQ_HANDLED;
> +	}
> +
> +	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
> +		nct6694_can_handle_bus_err(ndev, priv->event[can_idx].err);
> +		handled = IRQ_HANDLED;
> +	}
> +
> +	if (handled)
> +		can_rx_offload_threaded_irq_finish(&priv->offload);
> +
> +	if (priv->event[can_idx].tx_evt & NCT6694_CAN_EVT_TX_FIFO_EMPTY)
> +		nct6694_can_tx_irq(ndev);

Move this in front of the handled check and add "handled = IRQ_HANDLED;"
to the if-block.

> +
> +	priv->bec.rxerr = priv->event[can_idx].rec;
> +	priv->bec.txerr = priv->event[can_idx].tec;
> +
> +	return handled;
> +}
> +
> +static void nct6694_can_tx_work(struct work_struct *work)
> +{
> +	struct nct6694_can_priv *priv = container_of(work,
> +						     struct nct6694_can_priv,
> +						     tx_work);
> +	struct nct6694_can_frame *frame = &priv->tx;
> +	struct net_device *ndev = priv->ndev;
> +	struct net_device_stats *stats = &ndev->stats;
> +	struct sk_buff *skb = priv->can.echo_skb[0];
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_CAN_MOD,
> +		.cmd = NCT6694_CAN_DELIVER,
> +		.sel = NCT6694_CAN_DELIVER_SEL(1),
> +		.len = cpu_to_le16(sizeof(*frame))
> +	};
> +	u32 txid;
> +	int err;
> +
> +	memset(frame, 0, sizeof(*frame));
> +
> +	if (priv->can_idx == 0)
> +		frame->tag = NCT6694_CAN_FRAME_TAG_CAN0;
> +	else
> +		frame->tag = NCT6694_CAN_FRAME_TAG_CAN1;

        frame->tag = NCT6694_CAN_FRAME_TAG_CAN(priv->can_idx);
        
> +
> +	if (can_is_canfd_skb(skb)) {
> +		struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
> +
> +		if (cfd->flags & CANFD_BRS)
> +			frame->flag |= NCT6694_CAN_FRAME_FLAG_BRS;
> +
> +		if (cfd->can_id & CAN_EFF_FLAG) {
> +			txid = cfd->can_id & CAN_EFF_MASK;
> +			frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
> +		} else {
> +			txid = cfd->can_id & CAN_SFF_MASK;
> +		}
> +		frame->flag |= NCT6694_CAN_FRAME_FLAG_FD;
> +		frame->id = cpu_to_le32(txid);
> +		frame->length = cfd->len;
> +
> +		memcpy(frame->data, cfd->data, cfd->len);
> +	} else {
> +		struct can_frame *cf = (struct can_frame *)skb->data;
> +
> +		if (cf->can_id & CAN_EFF_FLAG) {
> +			txid = cf->can_id & CAN_EFF_MASK;
> +			frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
> +		} else {
> +			txid = cf->can_id & CAN_SFF_MASK;
> +		}
> +
> +		if (cf->can_id & CAN_RTR_FLAG)
> +			frame->flag |= NCT6694_CAN_FRAME_FLAG_RTR;
> +		else
> +			memcpy(frame->data, cf->data, cf->len);
> +
> +		frame->id = cpu_to_le32(txid);
> +		frame->length = cf->len;
> +	}
> +
> +	err = nct6694_write_msg(priv->nct6694, &cmd_hd, frame);
> +	if (err) {
> +		netdev_err(ndev, "%s: TX FIFO is full!\n", __func__);
> +		can_free_echo_skb(ndev, 0, NULL);
> +		stats->tx_dropped++;
> +		stats->tx_errors++;
> +		netif_wake_queue(ndev);
> +	}
> +}
> +
> +static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb,
> +					  struct net_device *ndev)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +
> +	if (can_dev_dropped_skb(ndev, skb))
> +		return NETDEV_TX_OK;
> +
> +	netif_stop_queue(ndev);
> +	can_put_echo_skb(skb, ndev, 0, 0);
> +	queue_work(priv->wq, &priv->tx_work);
> +
> +	return NETDEV_TX_OK;
> +}
> +
> +static int nct6694_can_start(struct net_device *ndev)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +	struct nct6694_can_setting *setting;
> +	struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_CAN_MOD,
> +		.cmd = NCT6694_CAN_SETTING,
> +		.sel = priv->can_idx,
> +		.len = cpu_to_le16(sizeof(*setting))
> +	};
> +	const struct can_bittiming *n_bt = &priv->can.bittiming;
> +	const struct can_bittiming *d_bt = &priv->can.data_bittiming;

nitpick:
move these 2 right after priv and d_bt first.

> +	int ret;
> +
> +	setting = kzalloc(sizeof(*setting), GFP_KERNEL);
> +	if (!setting)
> +		return -ENOMEM;
> +
> +	setting->nbr = cpu_to_le32(n_bt->bitrate);
> +	setting->dbr = cpu_to_le32(d_bt->bitrate);
> +
> +	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
> +		setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_MON);
> +
> +	if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&
> +	    priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)

We should move this check into the infrastructure. Please only check for
CAN_CTRLMODE_FD_NON_ISO.

> +		setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_NISO);
> +
> +	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
> +		setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_LBCK);
> +
> +	ret = nct6694_write_msg(priv->nct6694, &cmd_hd, setting);
> +	if (ret)
> +		goto exit;
> +
> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +
> +exit:
> +	kfree(setting);
> +	return ret;
> +}
> +
> +static int nct6694_can_stop(struct net_device *ndev)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +

How does the device know, that it should leave the CAN bus? Is there a
message you can send to it? If not put it at least into listen only mode.

> +	netif_stop_queue(ndev);
> +	free_irq(ndev->irq, ndev);
> +	destroy_workqueue(priv->wq);
> +	priv->wq = NULL;

no need to set wq to NULL

> +	priv->can.state = CAN_STATE_STOPPED;
> +	can_rx_offload_disable(&priv->offload);

Please change move can_rx_offload_disable() in front of "priv->can.state
= CAN_STATE_STOPPED".

> +	close_candev(ndev);
> +
> +	return 0;
> +}
> +
> +static int nct6694_can_set_mode(struct net_device *ndev, enum can_mode mode)
> +{
> +	switch (mode) {
> +	case CAN_MODE_START:
> +		nct6694_can_start(ndev);

please add error checking

> +		netif_wake_queue(ndev);
> +		return 0;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int nct6694_can_open(struct net_device *ndev)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +	int ret;
> +
> +	ret = open_candev(ndev);
> +	if (ret)
> +		return ret;
> +
> +	can_rx_offload_enable(&priv->offload);
> +
> +	ret = request_threaded_irq(ndev->irq, NULL,
> +				   nct6694_can_irq, IRQF_ONESHOT,
> +				   "nct6694_can", ndev);
> +	if (ret) {
> +		netdev_err(ndev, "Failed to request IRQ\n");
> +		goto close_candev;
> +	}
> +
> +	priv->wq = alloc_ordered_workqueue("%s-nct6694_wq",
> +					   WQ_FREEZABLE | WQ_MEM_RECLAIM,
> +					   ndev->name);
> +	if (!priv->wq) {
> +		ret = -ENOMEM;
> +		goto free_irq;
> +	}
> +
> +	ret = nct6694_can_start(ndev);
> +	if (ret)
> +		goto destroy_wq;
> +
> +	netif_start_queue(ndev);
> +
> +	return 0;
> +
> +destroy_wq:
> +	destroy_workqueue(priv->wq);
> +free_irq:
> +	free_irq(ndev->irq, ndev);
> +close_candev:
> +	can_rx_offload_disable(&priv->offload);
> +	close_candev(ndev);
> +	return ret;
> +}
> +
> +static const struct net_device_ops nct6694_can_netdev_ops = {
> +	.ndo_open = nct6694_can_open,
> +	.ndo_stop = nct6694_can_stop,
> +	.ndo_start_xmit = nct6694_can_start_xmit,
> +	.ndo_change_mtu = can_change_mtu,
> +};
> +
> +static const struct ethtool_ops nct6694_can_ethtool_ops = {
> +	.get_ts_info = ethtool_op_get_ts_info,
> +};
> +
> +static int nct6694_can_get_clock(struct nct6694_can_priv *priv)
> +{
> +	struct nct6694_can_information *info;
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_CAN_MOD,
> +		.cmd = NCT6694_CAN_INFORMATION,
> +		.sel = NCT6694_CAN_INFORMATION_SEL,
> +		.len = cpu_to_le16(sizeof(*info))
> +	};
> +	int ret, can_clk;
> +
> +	info = kzalloc(sizeof(*info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	ret = nct6694_read_msg(priv->nct6694, &cmd_hd, info);
> +	if (ret) {
> +		kfree(info);
> +		return ret;
> +	}
> +
> +	can_clk = le32_to_cpu(info->can_clk);
> +	kfree(info);
> +
> +	return can_clk;
> +}
> +
> +static int nct6694_can_probe(struct platform_device *pdev)
> +{
> +	const struct mfd_cell *cell = mfd_get_cell(pdev);
> +	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> +	struct nct6694_can_priv *priv;
> +	struct net_device *ndev;
> +	int ret, irq, can_clk;
> +
> +	irq = irq_create_mapping(nct6694->domain,
> +				 NCT6694_IRQ_CAN1 + cell->id);
> +	if (!irq)
> +		return irq;
> +
> +	ndev = alloc_candev(sizeof(struct nct6694_can_priv), 1);
> +	if (!ndev)
> +		return -ENOMEM;
> +
> +	ndev->irq = irq;
> +	ndev->flags |= IFF_ECHO;
> +	ndev->dev_port = cell->id;
> +	ndev->netdev_ops = &nct6694_can_netdev_ops;
> +	ndev->ethtool_ops = &nct6694_can_ethtool_ops;
> +
> +	priv = netdev_priv(ndev);
> +	priv->nct6694 = nct6694;
> +	priv->ndev = ndev;
> +
> +	can_clk = nct6694_can_get_clock(priv);
> +	if (can_clk < 0) {
> +		ret = dev_err_probe(&pdev->dev, can_clk,
> +				    "Failed to get clock\n");
> +		goto free_candev;
> +	}
> +
> +	INIT_WORK(&priv->tx_work, nct6694_can_tx_work);
> +
> +	priv->can_idx = cell->id;
> +	priv->can.state = CAN_STATE_STOPPED;

The device is allocated with CAN_STATE_STOPPED set, can be removed.

> +	priv->can.clock.freq = can_clk;
> +	priv->can.bittiming_const = &nct6694_can_bittiming_nominal_const;
> +	priv->can.data_bittiming_const = &nct6694_can_bittiming_data_const;
> +	priv->can.do_set_mode = nct6694_can_set_mode;
> +	priv->can.do_get_berr_counter = nct6694_can_get_berr_counter;
> +
> +	priv->can.ctrlmode = CAN_CTRLMODE_FD;
> +
> +	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK		|
> +				       CAN_CTRLMODE_LISTENONLY		|
> +				       CAN_CTRLMODE_FD			|
> +				       CAN_CTRLMODE_FD_NON_ISO		|
> +				       CAN_CTRLMODE_BERR_REPORTING;

nitpick: one space in front of "|" please

Does your device run in CAN-FD mode all the time? If so, please use
can_set_static_ctrlmode() to set it after priv->can.ctrlmode_supported
and remove CAN_CTRLMODE_FD from ctrlmode_supported.

> +
> +	ret = can_rx_offload_add_manual(ndev, &priv->offload,
> +					NCT6694_NAPI_WEIGHT);
> +	if (ret) {
> +		dev_err_probe(&pdev->dev, ret, "Failed to add rx_offload\n");
> +		goto free_candev;
> +	}
> +
> +	platform_set_drvdata(pdev, priv);
> +	SET_NETDEV_DEV(priv->ndev, &pdev->dev);
> +
> +	ret = register_candev(priv->ndev);
> +	if (ret)
> +		goto del_rx_offload;
> +
> +	return 0;
> +
> +del_rx_offload:

nitpick: please rename to rx_offload_del or can_rx_offload_del

> +	can_rx_offload_del(&priv->offload);
> +free_candev:
> +	free_candev(ndev);
> +	return ret;
> +}
> +
> +static void nct6694_can_remove(struct platform_device *pdev)
> +{
> +	struct nct6694_can_priv *priv = platform_get_drvdata(pdev);
> +
> +	cancel_work_sync(&priv->tx_work);

The workqueue has already been destroyed in nct6694_can_stop(), so more
work should be pending.

> +	unregister_candev(priv->ndev);
> +	can_rx_offload_del(&priv->offload);
> +	free_candev(priv->ndev);
> +}
> +
> +static struct platform_driver nct6694_can_driver = {
> +	.driver = {
> +		.name	= DRVNAME,
> +	},
> +	.probe		= nct6694_can_probe,
> +	.remove		= nct6694_can_remove,
> +};
> +
> +module_platform_driver(nct6694_can_driver);
> +
> +MODULE_DESCRIPTION("USB-CAN FD driver for NCT6694");
> +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:nct6694-can");
> -- 
> 2.34.1

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

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Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Vincent Mailhol]

On 07/02/2025 at 21:15, Marc Kleine-Budde wrote:
> On 07.02.2025 15:44:59, Ming Yu wrote:

(...)

>> +static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb,
>> +					  struct net_device *ndev)
>> +{
>> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
>> +
>> +	if (can_dev_dropped_skb(ndev, skb))
>> +		return NETDEV_TX_OK;
>> +
>> +	netif_stop_queue(ndev);
>> +	can_put_echo_skb(skb, ndev, 0, 0);
>> +	queue_work(priv->wq, &priv->tx_work);

What is the reason to use a work queue here? xmit() is not a hard IRQ.
Also, the other USB CAN devices just directly send the USB message in
their xmit() without the need to rely on such worker.

Sorry if this was discussed in the past, I can not remember if this
question has already been raised.

>> +	return NETDEV_TX_OK;
>> +}

(...)

Yours sincerely,
Vincent Mailhol

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Marc Kleine-Budde]

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On 08.02.2025 00:00:43, Vincent Mailhol wrote:
> On 07/02/2025 at 21:15, Marc Kleine-Budde wrote:
> > On 07.02.2025 15:44:59, Ming Yu wrote:
> 
> (...)
> 
> >> +static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb,
> >> +					  struct net_device *ndev)
> >> +{
> >> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> >> +
> >> +	if (can_dev_dropped_skb(ndev, skb))
> >> +		return NETDEV_TX_OK;
> >> +
> >> +	netif_stop_queue(ndev);
> >> +	can_put_echo_skb(skb, ndev, 0, 0);
> >> +	queue_work(priv->wq, &priv->tx_work);
> 
> What is the reason to use a work queue here? xmit() is not a hard IRQ.
> Also, the other USB CAN devices just directly send the USB message in
> their xmit() without the need to rely on such worker.
> 
> Sorry if this was discussed in the past, I can not remember if this
> question has already been raised.

AFAICS xmit uses nct6694_write_msg(), which uses several usb_bulk_msg(),
that can only be used from task context.

You can build a chain of usb_fill_bulk_urb(), usb_submit_urb(),
callbacks instead, but that's hard to read compared to blocking
usb_bulk_msg()s.

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

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Re: [PATCH v7 1/7] mfd: Add core driver for Nuvoton NCT6694

[Christophe JAILLET]

Le 07/02/2025 à 08:44, Ming Yu a écrit :
> The Nuvoton NCT6694 is a peripheral expander with 16 GPIO chips,
> 6 I2C controllers, 2 CANfd controllers, 2 Watchdog timers, ADC,
> PWM, and RTC.
> 
> This driver implements USB device functionality and shares the
> chip's peripherals as a child device.
> 
> Each child device can use the USB functions nct6694_read_msg()
> and nct6694_write_msg() to issue a command. They can also request
> interrupt that will be called when the USB device receives its
> interrupt pipe.

...

> +static struct irq_chip nct6694_irq_chip = {

This could be const.

(I'm working on a serie that should constify struct irq_chip, so this 
one would already be done)

> +	.name = "nct6694-irq",
> +	.flags = IRQCHIP_SKIP_SET_WAKE,
> +	.irq_bus_lock = nct6694_irq_lock,
> +	.irq_bus_sync_unlock = nct6694_irq_sync_unlock,
> +	.irq_enable = nct6694_irq_enable,
> +	.irq_disable = nct6694_irq_disable,
> +};
> +
> +static int nct6694_irq_domain_map(struct irq_domain *d, unsigned int irq,
> +				  irq_hw_number_t hw)
> +{
> +	struct nct6694 *nct6694 = d->host_data;
> +
> +	irq_set_chip_data(irq, nct6694);
> +	irq_set_chip_and_handler(irq, &nct6694_irq_chip, handle_simple_irq);
> +
> +	return 0;
> +}

...

CJ

Re: [PATCH v7 3/7] i2c: Add Nuvoton NCT6694 I2C support

[Christophe JAILLET]

Le 07/02/2025 à 08:44, Ming Yu a écrit :
> This driver supports I2C adapter functionality for NCT6694 MFD
> device based on USB interface, each I2C controller use default
> baudrate(100K).

...

> +static int nct6694_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
> +{
> +	struct nct6694_i2c_data *data = adap->algo_data;
> +	struct nct6694_i2c_deliver *deliver = &data->deliver;
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_I2C_MOD,
> +		.cmd = NCT6694_I2C_DELIVER,
> +		.sel = NCT6694_I2C_DELIVER_SEL,
> +		.len = cpu_to_le16(sizeof(*deliver))
> +	};
> +	int ret, i;
> +
> +	for (i = 0; i < num ; i++) {

Tiny tiny nitpick: unneeded extra space after num

> +		struct i2c_msg *msg_temp = &msgs[i];

...

CJ

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Christophe JAILLET]

Le 07/02/2025 à 08:44, Ming Yu a écrit :
> This driver supports Socket CANFD functionality for NCT6694 MFD
> device based on USB interface.

...

> +static int nct6694_can_start(struct net_device *ndev)
> +{
> +	struct nct6694_can_priv *priv = netdev_priv(ndev);
> +	struct nct6694_can_setting *setting;

Could be:
struct nct6694_can_setting *setting __free(kfree) = NULL;

to slightly simplify code below.


> +	struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_CAN_MOD,
> +		.cmd = NCT6694_CAN_SETTING,
> +		.sel = priv->can_idx,
> +		.len = cpu_to_le16(sizeof(*setting))
> +	};

...

> +static int nct6694_can_get_clock(struct nct6694_can_priv *priv)
> +{
> +	struct nct6694_can_information *info;

Could be:
struct nct6694_can_information *info __free(kfree) = NULL;

to slightly simplify code below.

> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_CAN_MOD,
> +		.cmd = NCT6694_CAN_INFORMATION,
> +		.sel = NCT6694_CAN_INFORMATION_SEL,
> +		.len = cpu_to_le16(sizeof(*info))
> +	};
> +	int ret, can_clk;
> +
> +	info = kzalloc(sizeof(*info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;

...

CJ

Re: [PATCH v7 5/7] watchdog: Add Nuvoton NCT6694 WDT support

[Christophe JAILLET]

Le 07/02/2025 à 08:45, Ming Yu a écrit :
> This driver supports Watchdog timer functionality for NCT6694 MFD
> device based on USB interface.

...

> +static int nct6694_wdt_probe(struct platform_device *pdev)
> +{
> +	const struct mfd_cell *cell = mfd_get_cell(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> +	struct nct6694_wdt_data *data;
> +	struct watchdog_device *wdev;
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->msg = devm_kzalloc(dev, sizeof(union nct6694_wdt_msg),
> +				 GFP_KERNEL);
> +	if (!data->msg)
> +		return -ENOMEM;
> +
> +	data->dev = dev;
> +	data->nct6694 = nct6694;
> +	data->wdev_idx = cell->id;
> +
> +	wdev = &data->wdev;
> +	wdev->info = &nct6694_wdt_info;
> +	wdev->ops = &nct6694_wdt_ops;
> +	wdev->timeout = timeout;
> +	wdev->pretimeout = pretimeout;
> +	if (timeout < pretimeout) {
> +		dev_warn(data->dev, "pretimeout < timeout. Setting to zero\n");
> +		wdev->pretimeout = 0;
> +	}
> +
> +	wdev->min_timeout = 1;
> +	wdev->max_timeout = 255;
> +
> +	devm_mutex_init(dev, &data->lock);

Error handling?
(also apply for patch 1/7 and 6/7)

> +
> +	platform_set_drvdata(pdev, data);
> +
> +	watchdog_set_drvdata(&data->wdev, data);
> +	watchdog_set_nowayout(&data->wdev, nowayout);
> +	watchdog_stop_on_reboot(&data->wdev);
> +
> +	return devm_watchdog_register_device(dev, &data->wdev);
> +}

...

CJ

Re: [PATCH v7 1/7] mfd: Add core driver for Nuvoton NCT6694

[Ming Yu]

Dear Christophe,

Thank you for reviewing,

Christophe JAILLET <christophe.jaillet@wanadoo.fr> 於 2025年2月8日 週六 上午2:37寫道：
>
> Le 07/02/2025 à 08:44, Ming Yu a écrit :
> > The Nuvoton NCT6694 is a peripheral expander with 16 GPIO chips,
> > 6 I2C controllers, 2 CANfd controllers, 2 Watchdog timers, ADC,
> > PWM, and RTC.
> >
> > This driver implements USB device functionality and shares the
> > chip's peripherals as a child device.
> >
> > Each child device can use the USB functions nct6694_read_msg()
> > and nct6694_write_msg() to issue a command. They can also request
> > interrupt that will be called when the USB device receives its
> > interrupt pipe.
>
> ...
>
> > +static struct irq_chip nct6694_irq_chip = {
>
> This could be const.
>
> (I'm working on a serie that should constify struct irq_chip, so this
> one would already be done)
>
Okay, I will fix it in the next patch.


Best regards,
Ming

Re: [PATCH v7 3/7] i2c: Add Nuvoton NCT6694 I2C support

[Ming Yu]

Dear Christophe,

Thank you for reviewing,

Christophe JAILLET <christophe.jaillet@wanadoo.fr> 於 2025年2月8日 週六 上午3:06寫道：
>
> Le 07/02/2025 à 08:44, Ming Yu a écrit :
> > This driver supports I2C adapter functionality for NCT6694 MFD
> > device based on USB interface, each I2C controller use default
> > baudrate(100K).
>
> ...
>
> > +static int nct6694_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
> > +{
> > +     struct nct6694_i2c_data *data = adap->algo_data;
> > +     struct nct6694_i2c_deliver *deliver = &data->deliver;
> > +     static const struct nct6694_cmd_header cmd_hd = {
> > +             .mod = NCT6694_I2C_MOD,
> > +             .cmd = NCT6694_I2C_DELIVER,
> > +             .sel = NCT6694_I2C_DELIVER_SEL,
> > +             .len = cpu_to_le16(sizeof(*deliver))
> > +     };
> > +     int ret, i;
> > +
> > +     for (i = 0; i < num ; i++) {
>
> Tiny tiny nitpick: unneeded extra space after num
>
Okay, I will fix it in the next patch.


Best regards,
Ming

Re: [PATCH v7 5/7] watchdog: Add Nuvoton NCT6694 WDT support

[Ming Yu]

Dear Christophe,

Thank you for reviewing,

Christophe JAILLET <christophe.jaillet@wanadoo.fr> 於 2025年2月8日 週六 上午4:30寫道：
>
> Le 07/02/2025 à 08:45, Ming Yu a écrit :
> > This driver supports Watchdog timer functionality for NCT6694 MFD
> > device based on USB interface.
>
> ...
>
> > +static int nct6694_wdt_probe(struct platform_device *pdev)
> > +{
> > +     const struct mfd_cell *cell = mfd_get_cell(pdev);
> > +     struct device *dev = &pdev->dev;
> > +     struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> > +     struct nct6694_wdt_data *data;
> > +     struct watchdog_device *wdev;
> > +
> > +     data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> > +     if (!data)
> > +             return -ENOMEM;
> > +
> > +     data->msg = devm_kzalloc(dev, sizeof(union nct6694_wdt_msg),
> > +                              GFP_KERNEL);
> > +     if (!data->msg)
> > +             return -ENOMEM;
> > +
> > +     data->dev = dev;
> > +     data->nct6694 = nct6694;
> > +     data->wdev_idx = cell->id;
> > +
> > +     wdev = &data->wdev;
> > +     wdev->info = &nct6694_wdt_info;
> > +     wdev->ops = &nct6694_wdt_ops;
> > +     wdev->timeout = timeout;
> > +     wdev->pretimeout = pretimeout;
> > +     if (timeout < pretimeout) {
> > +             dev_warn(data->dev, "pretimeout < timeout. Setting to zero\n");
> > +             wdev->pretimeout = 0;
> > +     }
> > +
> > +     wdev->min_timeout = 1;
> > +     wdev->max_timeout = 255;
> > +
> > +     devm_mutex_init(dev, &data->lock);
>
> Error handling?
> (also apply for patch 1/7 and 6/7)
>
I will add error handling for these in the next patch.


Best regards,
Ming

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Ming Yu]

Dear Marc,

Thank you for reviewing,

Marc Kleine-Budde <mkl@pengutronix.de> 於 2025年2月7日 週五 下午8:15寫道：
>
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Nuvoton NCT6694 Socket CANfd driver based on USB interface.
> > + *
> > + * Copyright (C) 2024 Nuvoton Technology Corp.
> > + */
>
> /* net-dev style multiline
>  * comments look like this
>  */
>

Okay, I will fix these comments in the next patch.

> > +
> > +#include <linux/can/dev.h>
> > +#include <linux/can/rx-offload.h>
> > +#include <linux/ethtool.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/kernel.h>
> > +#include <linux/mfd/core.h>
> > +#include <linux/mfd/nct6694.h>
> > +#include <linux/module.h>
> > +#include <linux/netdevice.h>
> > +#include <linux/platform_device.h>
> > +
> > +#define DRVNAME "nct6694_canfd"
> > +
> > +/*
> > + * USB command module type for NCT6694 CANfd controller.
> > + * This defines the module type used for communication with the NCT6694
> > + * CANfd controller over the USB interface.
> > + */
>
> /* net-dev style multiline
>  * comments look like this
>  */
>
> or remove the comment altogether as it's stating the obvious :)
>

Okay, I will remove it in the next patch.

> > +#define NCT6694_CAN_MOD                      0x05
> > +
> > +/* Command 00h - CAN Setting and Initialization */
> > +#define NCT6694_CAN_SETTING          0x00
> > +#define NCT6694_CAN_SETTING_CTRL1_MON        BIT(0)
> > +#define NCT6694_CAN_SETTING_CTRL1_NISO       BIT(1)
> > +#define NCT6694_CAN_SETTING_CTRL1_LBCK       BIT(2)
> > +
> > +/* Command 01h - CAN Information */
> > +#define NCT6694_CAN_INFORMATION              0x01
> > +#define NCT6694_CAN_INFORMATION_SEL  0x00
> > +
> > +/* Command 02h - CAN Event */
> > +#define NCT6694_CAN_EVENT            0x02
> > +#define NCT6694_CAN_EVENT_SEL(idx, mask)     \
> > +     ((idx ? 0x80 : 0x00) | ((mask) & 0x7F))
> > +
> > +#define NCT6694_CAN_EVENT_MASK               GENMASK(5, 0)
> > +#define NCT6694_CAN_EVT_TX_FIFO_EMPTY        BIT(7)  /* Read-clear */
> > +#define NCT6694_CAN_EVT_RX_DATA_LOST BIT(5)  /* Read-clear */
> > +#define NCT6694_CAN_EVT_RX_DATA_IN   BIT(7)  /* Read-clear*/
> > +
> > +/* Command 10h - CAN Deliver */
> > +#define NCT6694_CAN_DELIVER          0x10
> > +#define NCT6694_CAN_DELIVER_SEL(buf_cnt)     \
> > +     ((buf_cnt) & 0xFF)
> > +
> > +/* Command 11h - CAN Receive */
> > +#define NCT6694_CAN_RECEIVE          0x11
> > +#define NCT6694_CAN_RECEIVE_SEL(idx, buf_cnt)        \
> > +     ((idx ? 0x80 : 0x00) | ((buf_cnt) & 0x7F))
> > +
> > +#define NCT6694_CAN_FRAME_TAG_CAN0   0xC0
> > +#define NCT6694_CAN_FRAME_TAG_CAN1   0xC1
>
> in "include/linux/mfd/nct6694.h" it's CAN1 and CAN2, can you make it "0"
> based everywhere?
>

Understood. I will update these macros in the header.

> what about making it:
>
> #define NCT6694_CAN_FRAME_TAG_CAN(idx)  (0xC0 | (idx))
>

Fix it in the v8.

> > +#define NCT6694_CAN_FRAME_FLAG_EFF   BIT(0)
> > +#define NCT6694_CAN_FRAME_FLAG_RTR   BIT(1)
> > +#define NCT6694_CAN_FRAME_FLAG_FD    BIT(2)
> > +#define NCT6694_CAN_FRAME_FLAG_BRS   BIT(3)
> > +#define NCT6694_CAN_FRAME_FLAG_ERR   BIT(4)
> > +
> > +#define NCT6694_NAPI_WEIGHT          32
> > +
...
> > +struct nct6694_can_priv {
> > +     struct can_priv can;    /* must be the first member */
> > +     struct can_rx_offload offload;
> > +     struct net_device *ndev;
> > +     struct nct6694 *nct6694;
> > +     struct workqueue_struct *wq;
> > +     struct work_struct tx_work;
> > +     struct nct6694_can_frame tx;
> > +     struct nct6694_can_frame rx;
> > +     struct nct6694_can_event event[2];
> > +     struct can_berr_counter bec;
> > +     unsigned char can_idx;
>
> can you use ndev->dev_port instead?
>

Fix it in the v8.

> > +};
> > +
...
> > +static void nct6694_can_rx(struct net_device *ndev, u8 rx_evt)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +     struct nct6694_can_frame *frame = &priv->rx;
> > +     struct nct6694_cmd_header cmd_hd = {
> > +             .mod = NCT6694_CAN_MOD,
> > +             .cmd = NCT6694_CAN_RECEIVE,
> > +             .sel = NCT6694_CAN_RECEIVE_SEL(priv->can_idx, 1),
> > +             .len = cpu_to_le16(sizeof(*frame))
> > +     };
> > +     struct sk_buff *skb;
> > +     int ret;
> > +
> > +     ret = nct6694_read_msg(priv->nct6694, &cmd_hd, frame);
> > +     if (ret)
> > +             return;
> > +
> > +     if (frame->flag & NCT6694_CAN_FRAME_FLAG_FD) {
> > +             struct canfd_frame *cfd;
> > +
> > +             skb = alloc_canfd_skb(priv->ndev, &cfd);
> > +             if (!skb)
> > +                     return;
> > +
> > +             cfd->can_id = le32_to_cpu(frame->id);
> > +             cfd->len = canfd_sanitize_len(frame->length);
> > +             if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
> > +                     cfd->can_id |= CAN_EFF_FLAG;
> > +             if (frame->flag & NCT6694_CAN_FRAME_FLAG_BRS)
> > +                     cfd->flags |= CANFD_BRS;
> > +             if (frame->flag & NCT6694_CAN_FRAME_FLAG_ERR)
> > +                     cfd->flags |= CANFD_ESI;
> > +
> > +             memcpy(cfd->data, frame->data, cfd->len);
> > +     } else {
> > +             struct can_frame *cf;
> > +
> > +             skb = alloc_can_skb(priv->ndev, &cf);
> > +             if (!skb)
> > +                     return;
> > +
> > +             cf->can_id = le32_to_cpu(frame->id);
> > +             cf->len = min_t(u8, frame->length, CAN_MAX_DLEN);
>
> use can_cc_dlc2len()
>

Fix it in the v8.

> > +             if (frame->flag & NCT6694_CAN_FRAME_FLAG_EFF)
> > +                     cf->can_id |= CAN_EFF_FLAG;
> > +
> > +             if (frame->flag & NCT6694_CAN_FRAME_FLAG_RTR)
> > +                     cf->can_id |= CAN_RTR_FLAG;
> > +             else
> > +                     memcpy(cf->data, frame->data, cf->len);
> > +     }
> > +
> > +     nct6694_can_rx_offload(&priv->offload, skb);
> > +}
> > +
> > +static int nct6694_can_get_berr_counter(const struct net_device *ndev,
> > +                                     struct can_berr_counter *bec)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +
> > +     *bec = priv->bec;
> > +
> > +     return 0;
> > +}
> > +
> > +static void nct6694_can_handle_state_change(struct net_device *ndev,
> > +                                         enum can_state new_state)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +     struct can_berr_counter bec;
> > +     struct can_frame *cf;
> > +     struct sk_buff *skb;
> > +
> > +     skb = alloc_can_err_skb(ndev, &cf);
> > +
> > +     nct6694_can_get_berr_counter(ndev, &bec);
> > +
> > +     switch (new_state) {
> > +     case CAN_STATE_ERROR_ACTIVE:
> > +             priv->can.can_stats.error_warning++;
>                                     ^^^^^^^^^^^^^
> > +             priv->can.state = CAN_STATE_ERROR_ACTIVE;
> > +             if (cf)
> > +                     cf->data[1] |= CAN_ERR_CRTL_ACTIVE;
> > +             break;
> > +     case CAN_STATE_ERROR_WARNING:
> > +             priv->can.can_stats.error_warning++;
> > +             priv->can.state = CAN_STATE_ERROR_WARNING;
> > +             if (cf) {
> > +                     cf->can_id |= CAN_ERR_CRTL;
> > +                     if (bec.txerr > bec.rxerr)
> > +                             cf->data[1] = CAN_ERR_CRTL_TX_WARNING;
> > +                     else
> > +                             cf->data[1] = CAN_ERR_CRTL_RX_WARNING;
> > +                     cf->data[6] = bec.txerr;
> > +                     cf->data[7] = bec.rxerr;
> > +             }
> > +             break;
> > +     case CAN_STATE_ERROR_PASSIVE:
> > +             priv->can.can_stats.error_passive++;
> > +             priv->can.state = CAN_STATE_ERROR_PASSIVE;
> > +             if (cf) {
> > +                     cf->can_id |= CAN_ERR_CRTL;
> > +                     cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
> > +                     if (bec.txerr >= CAN_ERROR_PASSIVE_THRESHOLD)
> > +                             cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
> > +                     cf->data[6] = bec.txerr;
> > +                     cf->data[7] = bec.rxerr;
> > +             }
> > +             break;
> > +     case CAN_STATE_BUS_OFF:
> > +             priv->can.state = CAN_STATE_BUS_OFF;
> > +             priv->can.can_stats.bus_off++;
> > +             if (cf)
> > +                     cf->can_id |= CAN_ERR_BUSOFF;
> > +             can_free_echo_skb(ndev, 0, NULL);
> > +             netif_stop_queue(ndev);
> > +             can_bus_off(ndev);
> > +             break;
> > +     default:
> > +             break;
> > +     }
> > +
> > +     nct6694_can_rx_offload(&priv->offload, skb);
> > +}
> > +
> > +static void nct6694_can_handle_state_errors(struct net_device *ndev, u8 status)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
>
> It seems you don't have dedicated RX and TX states, so call
> nct6694_can_get_berr_counter() and use can_state_get_by_berr_counter()
> to get the states. Then basically do that what what
> mcp251xfd_handle_cerrif() does, starting with "new_state = max(tx_state, rx_state);"
>

Excuse me, do you mean that nct6694_can_handle_state_change() the flow
should like v5?
https://lore.kernel.org/linux-can/CAMZ6RqLHEoukxDfV33iDWXjM1baK922QnWSkOP01VzZ0S_9H8g@mail.gmail.com/

> > +
> > +     if (status == NCT6694_CAN_EVT_STS_ERROR_ACTIVE &&
> > +         priv->can.state != CAN_STATE_ERROR_ACTIVE) {
> > +             netdev_dbg(ndev, "Error, entered active state\n");
> > +             nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_ACTIVE);
> > +     }
> > +
> > +     if (status == NCT6694_CAN_EVT_STS_WARNING &&
> > +         priv->can.state != CAN_STATE_ERROR_WARNING) {
> > +             netdev_dbg(ndev, "Error, entered warning state\n");
> > +             nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_WARNING);
> > +     }
> > +
> > +     if (status == NCT6694_CAN_EVT_STS_ERROR_PASSIVE &&
> > +         priv->can.state != CAN_STATE_ERROR_PASSIVE) {
> > +             netdev_dbg(ndev, "Error, entered passive state\n");
> > +             nct6694_can_handle_state_change(ndev, CAN_STATE_ERROR_PASSIVE);
> > +     }
> > +
> > +     if (status == NCT6694_CAN_EVT_STS_BUS_OFF &&
> > +         priv->can.state != CAN_STATE_BUS_OFF) {
> > +             netdev_dbg(ndev, "Error, entered bus-off state\n");
> > +             nct6694_can_handle_state_change(ndev, CAN_STATE_BUS_OFF);
> > +     }
> > +}
> > +
> > +static void nct6694_can_handle_bus_err(struct net_device *ndev, u8 bus_err)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +     struct can_frame *cf;
> > +     struct sk_buff *skb;
> > +
> > +     if (bus_err == NCT6694_CAN_EVT_ERR_NO_ERROR)
> > +             return;
> > +
> > +     priv->can.can_stats.bus_error++;
> > +
> > +     skb = alloc_can_err_skb(ndev, &cf);
> > +     if (skb)
> > +             cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> > +
> > +     switch (bus_err) {
> > +     case NCT6694_CAN_EVT_ERR_CRC_ERROR:
> > +             netdev_dbg(ndev, "CRC error\n");
> > +             ndev->stats.rx_errors++;
> > +             if (skb)
> > +                     cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
> > +             break;
> > +
> > +     case NCT6694_CAN_EVT_ERR_STUFF_ERROR:
> > +             netdev_dbg(ndev, "Stuff error\n");
> > +             ndev->stats.rx_errors++;
> > +             if (skb)
> > +                     cf->data[2] |= CAN_ERR_PROT_STUFF;
> > +             break;
> > +
> > +     case NCT6694_CAN_EVT_ERR_ACK_ERROR:
> > +             netdev_dbg(ndev, "Ack error\n");
> > +             ndev->stats.tx_errors++;
> > +             if (skb) {
> > +                     cf->can_id |= CAN_ERR_ACK;
> > +                     cf->data[2] |= CAN_ERR_PROT_TX;
> > +             }
> > +             break;
> > +
> > +     case NCT6694_CAN_EVT_ERR_FORM_ERROR:
> > +             netdev_dbg(ndev, "Form error\n");
> > +             ndev->stats.rx_errors++;
> > +             if (skb)
> > +                     cf->data[2] |= CAN_ERR_PROT_FORM;
> > +             break;
> > +
> > +     case NCT6694_CAN_EVT_ERR_BIT_ERROR:
> > +             netdev_dbg(ndev, "Bit error\n");
> > +             ndev->stats.tx_errors++;
> > +             if (skb)
> > +                     cf->data[2] |= CAN_ERR_PROT_TX | CAN_ERR_PROT_BIT;
> > +             break;
> > +
> > +     default:
> > +             break;
> > +     }
> > +
>
> missing check:
>
>         if (skb)
>

Fix it in the v8.

> > +     nct6694_can_rx_offload(&priv->offload, skb);
> > +}
> > +
> > +static void nct6694_can_tx_irq(struct net_device *ndev)
> > +{
> > +     struct net_device_stats *stats = &ndev->stats;
> > +
> > +     stats->tx_bytes += can_get_echo_skb(ndev, 0, NULL);
>
> use can_rx_offload_get_echo_skb_queue_tail() here
>

Fix it in the v8.

> > +     stats->tx_packets++;
> > +     netif_wake_queue(ndev);
> > +}
> > +
> > +static irqreturn_t nct6694_can_irq(int irq, void *data)
> > +{
> > +     struct net_device *ndev = data;
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +     struct nct6694_can_event *evt = priv->event;
> > +     struct nct6694_cmd_header cmd_hd = {
> > +             .mod = NCT6694_CAN_MOD,
> > +             .cmd = NCT6694_CAN_EVENT,
> > +             .sel = NCT6694_CAN_EVENT_SEL(priv->can_idx, NCT6694_CAN_EVENT_MASK),
> > +             .len = cpu_to_le16(sizeof(priv->event))
> > +     };
> > +     irqreturn_t handled = IRQ_NONE;
> > +     int can_idx = priv->can_idx;
> > +     int ret;
>
> it would make sense to have a event pointer here instead of the can_idx?
>
>         const struct nct6694_can_event *event = &priv->event[priv->can_idx];
>

Fix it in the v8.

> > +
> > +     ret = nct6694_read_msg(priv->nct6694, &cmd_hd, evt);
> > +     if (ret < 0)
> > +             return handled;
> > +
> > +     if (priv->event[can_idx].rx_evt & NCT6694_CAN_EVT_RX_DATA_IN) {
> > +             nct6694_can_rx(ndev, priv->event[can_idx].rx_evt);
> > +             handled = IRQ_HANDLED;
> > +     }
> > +
> > +     if (priv->event[can_idx].rx_evt & NCT6694_CAN_EVT_RX_DATA_LOST) {
> > +             nct6694_can_handle_lost_msg(ndev);
> > +             handled = IRQ_HANDLED;
> > +     }
> > +
> > +     if (priv->event[can_idx].status) {
> > +             nct6694_can_handle_state_errors(ndev, priv->event[can_idx].status);
> > +             handled = IRQ_HANDLED;
> > +     }
> > +
> > +     if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
> > +             nct6694_can_handle_bus_err(ndev, priv->event[can_idx].err);
> > +             handled = IRQ_HANDLED;
> > +     }
> > +
> > +     if (handled)
> > +             can_rx_offload_threaded_irq_finish(&priv->offload);
> > +
> > +     if (priv->event[can_idx].tx_evt & NCT6694_CAN_EVT_TX_FIFO_EMPTY)
> > +             nct6694_can_tx_irq(ndev);
>
> Move this in front of the handled check and add "handled = IRQ_HANDLED;"
> to the if-block.
>

Fix it in the v8.

> > +
> > +     priv->bec.rxerr = priv->event[can_idx].rec;
> > +     priv->bec.txerr = priv->event[can_idx].tec;
> > +
> > +     return handled;
> > +}
> > +
> > +static void nct6694_can_tx_work(struct work_struct *work)
> > +{
> > +     struct nct6694_can_priv *priv = container_of(work,
> > +                                                  struct nct6694_can_priv,
> > +                                                  tx_work);
> > +     struct nct6694_can_frame *frame = &priv->tx;
> > +     struct net_device *ndev = priv->ndev;
> > +     struct net_device_stats *stats = &ndev->stats;
> > +     struct sk_buff *skb = priv->can.echo_skb[0];
> > +     static const struct nct6694_cmd_header cmd_hd = {
> > +             .mod = NCT6694_CAN_MOD,
> > +             .cmd = NCT6694_CAN_DELIVER,
> > +             .sel = NCT6694_CAN_DELIVER_SEL(1),
> > +             .len = cpu_to_le16(sizeof(*frame))
> > +     };
> > +     u32 txid;
> > +     int err;
> > +
> > +     memset(frame, 0, sizeof(*frame));
> > +
> > +     if (priv->can_idx == 0)
> > +             frame->tag = NCT6694_CAN_FRAME_TAG_CAN0;
> > +     else
> > +             frame->tag = NCT6694_CAN_FRAME_TAG_CAN1;
>
>         frame->tag = NCT6694_CAN_FRAME_TAG_CAN(priv->can_idx);
>

Fix it in the v8.

> > +
> > +     if (can_is_canfd_skb(skb)) {
> > +             struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
> > +
> > +             if (cfd->flags & CANFD_BRS)
> > +                     frame->flag |= NCT6694_CAN_FRAME_FLAG_BRS;
> > +
> > +             if (cfd->can_id & CAN_EFF_FLAG) {
> > +                     txid = cfd->can_id & CAN_EFF_MASK;
> > +                     frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
> > +             } else {
> > +                     txid = cfd->can_id & CAN_SFF_MASK;
> > +             }
> > +             frame->flag |= NCT6694_CAN_FRAME_FLAG_FD;
> > +             frame->id = cpu_to_le32(txid);
> > +             frame->length = cfd->len;
> > +
> > +             memcpy(frame->data, cfd->data, cfd->len);
> > +     } else {
> > +             struct can_frame *cf = (struct can_frame *)skb->data;
> > +
> > +             if (cf->can_id & CAN_EFF_FLAG) {
> > +                     txid = cf->can_id & CAN_EFF_MASK;
> > +                     frame->flag |= NCT6694_CAN_FRAME_FLAG_EFF;
> > +             } else {
> > +                     txid = cf->can_id & CAN_SFF_MASK;
> > +             }
> > +
> > +             if (cf->can_id & CAN_RTR_FLAG)
> > +                     frame->flag |= NCT6694_CAN_FRAME_FLAG_RTR;
> > +             else
> > +                     memcpy(frame->data, cf->data, cf->len);
> > +
> > +             frame->id = cpu_to_le32(txid);
> > +             frame->length = cf->len;
> > +     }
> > +
> > +     err = nct6694_write_msg(priv->nct6694, &cmd_hd, frame);
> > +     if (err) {
> > +             netdev_err(ndev, "%s: TX FIFO is full!\n", __func__);
> > +             can_free_echo_skb(ndev, 0, NULL);
> > +             stats->tx_dropped++;
> > +             stats->tx_errors++;
> > +             netif_wake_queue(ndev);
> > +     }
> > +}
> > +
> > +static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb,
> > +                                       struct net_device *ndev)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +
> > +     if (can_dev_dropped_skb(ndev, skb))
> > +             return NETDEV_TX_OK;
> > +
> > +     netif_stop_queue(ndev);
> > +     can_put_echo_skb(skb, ndev, 0, 0);
> > +     queue_work(priv->wq, &priv->tx_work);
> > +
> > +     return NETDEV_TX_OK;
> > +}
> > +
> > +static int nct6694_can_start(struct net_device *ndev)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +     struct nct6694_can_setting *setting;
> > +     struct nct6694_cmd_header cmd_hd = {
> > +             .mod = NCT6694_CAN_MOD,
> > +             .cmd = NCT6694_CAN_SETTING,
> > +             .sel = priv->can_idx,
> > +             .len = cpu_to_le16(sizeof(*setting))
> > +     };
> > +     const struct can_bittiming *n_bt = &priv->can.bittiming;
> > +     const struct can_bittiming *d_bt = &priv->can.data_bittiming;
>
> nitpick:
> move these 2 right after priv and d_bt first.
>

Fix it in the v8.

> > +     int ret;
> > +
> > +     setting = kzalloc(sizeof(*setting), GFP_KERNEL);
> > +     if (!setting)
> > +             return -ENOMEM;
> > +
> > +     setting->nbr = cpu_to_le32(n_bt->bitrate);
> > +     setting->dbr = cpu_to_le32(d_bt->bitrate);
> > +
> > +     if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
> > +             setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_MON);
> > +
> > +     if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&
> > +         priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
>
> We should move this check into the infrastructure. Please only check for
> CAN_CTRLMODE_FD_NON_ISO.
>

Fix it in the v8.

> > +             setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_NISO);
> > +
> > +     if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
> > +             setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_SETTING_CTRL1_LBCK);
> > +
> > +     ret = nct6694_write_msg(priv->nct6694, &cmd_hd, setting);
> > +     if (ret)
> > +             goto exit;
> > +
> > +     priv->can.state = CAN_STATE_ERROR_ACTIVE;
> > +
> > +exit:
> > +     kfree(setting);
> > +     return ret;
> > +}
> > +
> > +static int nct6694_can_stop(struct net_device *ndev)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +
>
> How does the device know, that it should leave the CAN bus? Is there a
> message you can send to it? If not put it at least into listen only mode.
>

My device only resets upon receiving the initial command, so can I
assign priv->can.ctrlmode = CAN_CTRLMODE_LISTENONLY directly?

> > +     netif_stop_queue(ndev);
> > +     free_irq(ndev->irq, ndev);
> > +     destroy_workqueue(priv->wq);
> > +     priv->wq = NULL;
>
> no need to set wq to NULL
>

Fix it in the v8.

> > +     priv->can.state = CAN_STATE_STOPPED;
> > +     can_rx_offload_disable(&priv->offload);
>
> Please change move can_rx_offload_disable() in front of "priv->can.state
> = CAN_STATE_STOPPED".
>

Fix it in the v8.

> > +     close_candev(ndev);
> > +
> > +     return 0;
> > +}
> > +
> > +static int nct6694_can_set_mode(struct net_device *ndev, enum can_mode mode)
> > +{
> > +     switch (mode) {
> > +     case CAN_MODE_START:
> > +             nct6694_can_start(ndev);
>
> please add error checking
>

Fix it in the v8.

> > +             netif_wake_queue(ndev);
> > +             return 0;
> > +     default:
> > +             return -EOPNOTSUPP;
> > +     }
> > +}
> > +
...
> > +static int nct6694_can_probe(struct platform_device *pdev)
> > +{
> > +     const struct mfd_cell *cell = mfd_get_cell(pdev);
> > +     struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> > +     struct nct6694_can_priv *priv;
> > +     struct net_device *ndev;
> > +     int ret, irq, can_clk;
> > +
> > +     irq = irq_create_mapping(nct6694->domain,
> > +                              NCT6694_IRQ_CAN1 + cell->id);
> > +     if (!irq)
> > +             return irq;
> > +
> > +     ndev = alloc_candev(sizeof(struct nct6694_can_priv), 1);
> > +     if (!ndev)
> > +             return -ENOMEM;
> > +
> > +     ndev->irq = irq;
> > +     ndev->flags |= IFF_ECHO;
> > +     ndev->dev_port = cell->id;
> > +     ndev->netdev_ops = &nct6694_can_netdev_ops;
> > +     ndev->ethtool_ops = &nct6694_can_ethtool_ops;
> > +
> > +     priv = netdev_priv(ndev);
> > +     priv->nct6694 = nct6694;
> > +     priv->ndev = ndev;
> > +
> > +     can_clk = nct6694_can_get_clock(priv);
> > +     if (can_clk < 0) {
> > +             ret = dev_err_probe(&pdev->dev, can_clk,
> > +                                 "Failed to get clock\n");
> > +             goto free_candev;
> > +     }
> > +
> > +     INIT_WORK(&priv->tx_work, nct6694_can_tx_work);
> > +
> > +     priv->can_idx = cell->id;
> > +     priv->can.state = CAN_STATE_STOPPED;
>
> The device is allocated with CAN_STATE_STOPPED set, can be removed.
>

Fix it in the v8.

> > +     priv->can.clock.freq = can_clk;
> > +     priv->can.bittiming_const = &nct6694_can_bittiming_nominal_const;
> > +     priv->can.data_bittiming_const = &nct6694_can_bittiming_data_const;
> > +     priv->can.do_set_mode = nct6694_can_set_mode;
> > +     priv->can.do_get_berr_counter = nct6694_can_get_berr_counter;
> > +
> > +     priv->can.ctrlmode = CAN_CTRLMODE_FD;
> > +
> > +     priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK            |
> > +                                    CAN_CTRLMODE_LISTENONLY          |
> > +                                    CAN_CTRLMODE_FD                  |
> > +                                    CAN_CTRLMODE_FD_NON_ISO          |
> > +                                    CAN_CTRLMODE_BERR_REPORTING;
>
> nitpick: one space in front of "|" please
>
> Does your device run in CAN-FD mode all the time? If so, please use
> can_set_static_ctrlmode() to set it after priv->can.ctrlmode_supported
> and remove CAN_CTRLMODE_FD from ctrlmode_supported.
>

Fix it in the v8.

> > +
> > +     ret = can_rx_offload_add_manual(ndev, &priv->offload,
> > +                                     NCT6694_NAPI_WEIGHT);
> > +     if (ret) {
> > +             dev_err_probe(&pdev->dev, ret, "Failed to add rx_offload\n");
> > +             goto free_candev;
> > +     }
> > +
> > +     platform_set_drvdata(pdev, priv);
> > +     SET_NETDEV_DEV(priv->ndev, &pdev->dev);
> > +
> > +     ret = register_candev(priv->ndev);
> > +     if (ret)
> > +             goto del_rx_offload;
> > +
> > +     return 0;
> > +
> > +del_rx_offload:
>
> nitpick: please rename to rx_offload_del or can_rx_offload_del
>

Fix it in the v8.

> > +     can_rx_offload_del(&priv->offload);
> > +free_candev:
> > +     free_candev(ndev);
> > +     return ret;
> > +}
> > +
> > +static void nct6694_can_remove(struct platform_device *pdev)
> > +{
> > +     struct nct6694_can_priv *priv = platform_get_drvdata(pdev);
> > +
> > +     cancel_work_sync(&priv->tx_work);
>
> The workqueue has already been destroyed in nct6694_can_stop(), so more
> work should be pending.
>

Fix it in the v8.

> > +     unregister_candev(priv->ndev);
> > +     can_rx_offload_del(&priv->offload);
> > +     free_candev(priv->ndev);
> > +}
> > +


Best regards,
Ming

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Ming Yu]

Dear Vincent,

Thank you for reviewing,
this part is as Marc mentioned.


Best regards,
Ming

Vincent Mailhol <mailhol.vincent@wanadoo.fr> 於 2025年2月7日 週五 下午11:01寫道：
>
> On 07/02/2025 at 21:15, Marc Kleine-Budde wrote:
> > On 07.02.2025 15:44:59, Ming Yu wrote:
>
> (...)
>
> >> +static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb,
> >> +                                      struct net_device *ndev)
> >> +{
> >> +    struct nct6694_can_priv *priv = netdev_priv(ndev);
> >> +
> >> +    if (can_dev_dropped_skb(ndev, skb))
> >> +            return NETDEV_TX_OK;
> >> +
> >> +    netif_stop_queue(ndev);
> >> +    can_put_echo_skb(skb, ndev, 0, 0);
> >> +    queue_work(priv->wq, &priv->tx_work);
>
> What is the reason to use a work queue here? xmit() is not a hard IRQ.
> Also, the other USB CAN devices just directly send the USB message in
> their xmit() without the need to rely on such worker.
>
> Sorry if this was discussed in the past, I can not remember if this
> question has already been raised.
>
> >> +    return NETDEV_TX_OK;
> >> +}
>
> (...)
>
> Yours sincerely,
> Vincent Mailhol
>

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Ming Yu]

Dear Christophe,

Thank you for reviewing,
I will make the change in the next patch.


Best regards,
Ming

Christophe JAILLET <christophe.jaillet@wanadoo.fr> 於 2025年2月8日 週六 上午3:18寫道：
>
> Le 07/02/2025 à 08:44, Ming Yu a écrit :
> > This driver supports Socket CANFD functionality for NCT6694 MFD
> > device based on USB interface.
>
> ...
>
> > +static int nct6694_can_start(struct net_device *ndev)
> > +{
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +     struct nct6694_can_setting *setting;
>
> Could be:
> struct nct6694_can_setting *setting __free(kfree) = NULL;
>
> to slightly simplify code below.
>
>
> > +     struct nct6694_cmd_header cmd_hd = {
> > +             .mod = NCT6694_CAN_MOD,
> > +             .cmd = NCT6694_CAN_SETTING,
> > +             .sel = priv->can_idx,
> > +             .len = cpu_to_le16(sizeof(*setting))
> > +     };
>
> ...
>
> > +static int nct6694_can_get_clock(struct nct6694_can_priv *priv)
> > +{
> > +     struct nct6694_can_information *info;
>
> Could be:
> struct nct6694_can_information *info __free(kfree) = NULL;
>
> to slightly simplify code below.
>
> > +     static const struct nct6694_cmd_header cmd_hd = {
> > +             .mod = NCT6694_CAN_MOD,
> > +             .cmd = NCT6694_CAN_INFORMATION,
> > +             .sel = NCT6694_CAN_INFORMATION_SEL,
> > +             .len = cpu_to_le16(sizeof(*info))
> > +     };
> > +     int ret, can_clk;
> > +
> > +     info = kzalloc(sizeof(*info), GFP_KERNEL);
> > +     if (!info)
> > +             return -ENOMEM;
>
> ...
>
> CJ
>

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Ming Yu]

Hi Marc,

Marc Kleine-Budde <mkl@pengutronix.de> 於 2025年2月7日 週五 下午8:15寫道：
>
> > +static irqreturn_t nct6694_can_irq(int irq, void *data)
> > +{
> > +     struct net_device *ndev = data;
> > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +     struct nct6694_can_event *evt = priv->event;
> > +     struct nct6694_cmd_header cmd_hd = {
> > +             .mod = NCT6694_CAN_MOD,
> > +             .cmd = NCT6694_CAN_EVENT,
> > +             .sel = NCT6694_CAN_EVENT_SEL(priv->can_idx, NCT6694_CAN_EVENT_MASK),
> > +             .len = cpu_to_le16(sizeof(priv->event))
> > +     };
> > +     irqreturn_t handled = IRQ_NONE;
> > +     int can_idx = priv->can_idx;
> > +     int ret;
>
> it would make sense to have a event pointer here instead of the can_idx?
>
>         const struct nct6694_can_event *event = &priv->event[priv->can_idx];
>
The CAN Event command always returns 16bytes: the first 8 bytes
correspond to the CAN0 event, and the last 8 bytes correspond to the
CAN1 event. Therefore, the event pointer here refers to both event
buffers.

Thanks,
Ming

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Marc Kleine-Budde]

[-- Attachment #1: Type: text/plain, Size: 1657 bytes --]

On 21.02.2025 16:01:07, Ming Yu wrote:
> Hi Marc,
> 
> Marc Kleine-Budde <mkl@pengutronix.de> 於 2025年2月7日 週五 下午8:15寫道：
> >
> > > +static irqreturn_t nct6694_can_irq(int irq, void *data)
> > > +{
> > > +     struct net_device *ndev = data;
> > > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > > +     struct nct6694_can_event *evt = priv->event;
> > > +     struct nct6694_cmd_header cmd_hd = {
> > > +             .mod = NCT6694_CAN_MOD,
> > > +             .cmd = NCT6694_CAN_EVENT,
> > > +             .sel = NCT6694_CAN_EVENT_SEL(priv->can_idx, NCT6694_CAN_EVENT_MASK),
> > > +             .len = cpu_to_le16(sizeof(priv->event))
> > > +     };
> > > +     irqreturn_t handled = IRQ_NONE;
> > > +     int can_idx = priv->can_idx;
> > > +     int ret;
> >
> > it would make sense to have a event pointer here instead of the can_idx?
> >
> >         const struct nct6694_can_event *event = &priv->event[priv->can_idx];
> >
> The CAN Event command always returns 16bytes: the first 8 bytes
> correspond to the CAN0 event, and the last 8 bytes correspond to the
> CAN1 event. Therefore, the event pointer here refers to both event
> buffers.

Yes, but in the following code uses "priv->event[can_idx]" several
times, this is why I proposed to have a dedicated "struct
nct6694_can_event *event" variable.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

[-- Attachment #2: signature.asc --]
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Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Ming Yu]

Marc Kleine-Budde <mkl@pengutronix.de> 於 2025年2月21日 週五 下午4:08寫道：
>
> On 21.02.2025 16:01:07, Ming Yu wrote:
> > Hi Marc,
> >
> > Marc Kleine-Budde <mkl@pengutronix.de> 於 2025年2月7日 週五 下午8:15寫道：
> > >
> > > > +static irqreturn_t nct6694_can_irq(int irq, void *data)
> > > > +{
> > > > +     struct net_device *ndev = data;
> > > > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> > > > +     struct nct6694_can_event *evt = priv->event;
> > > > +     struct nct6694_cmd_header cmd_hd = {
> > > > +             .mod = NCT6694_CAN_MOD,
> > > > +             .cmd = NCT6694_CAN_EVENT,
> > > > +             .sel = NCT6694_CAN_EVENT_SEL(priv->can_idx, NCT6694_CAN_EVENT_MASK),
> > > > +             .len = cpu_to_le16(sizeof(priv->event))
> > > > +     };
> > > > +     irqreturn_t handled = IRQ_NONE;
> > > > +     int can_idx = priv->can_idx;
> > > > +     int ret;
> > >
> > > it would make sense to have a event pointer here instead of the can_idx?
> > >
> > >         const struct nct6694_can_event *event = &priv->event[priv->can_idx];
> > >
> > The CAN Event command always returns 16bytes: the first 8 bytes
> > correspond to the CAN0 event, and the last 8 bytes correspond to the
> > CAN1 event. Therefore, the event pointer here refers to both event
> > buffers.
>
> Yes, but in the following code uses "priv->event[can_idx]" several
> times, this is why I proposed to have a dedicated "struct
> nct6694_can_event *event" variable.
>
Okay, I'll update the code.


Thanks,
Ming

Re: [PATCH v7 4/7] can: Add Nuvoton NCT6694 CANFD support

[Marc Kleine-Budde]

[-- Attachment #1: Type: text/plain, Size: 4204 bytes --]

On 12.02.2025 10:49:43, Ming Yu wrote:
> > > +static void nct6694_can_handle_state_errors(struct net_device *ndev, u8 status)
> > > +{
> > > +     struct nct6694_can_priv *priv = netdev_priv(ndev);
> >
> > It seems you don't have dedicated RX and TX states, so call
> > nct6694_can_get_berr_counter() and use can_state_get_by_berr_counter()
> > to get the states. Then basically do that what what
> > mcp251xfd_handle_cerrif() does, starting with "new_state = max(tx_state, rx_state);"
> >
> 
> Excuse me, do you mean that nct6694_can_handle_state_change() the flow
> should like v5?
> https://lore.kernel.org/linux-can/CAMZ6RqLHEoukxDfV33iDWXjM1baK922QnWSkOP01VzZ0S_9H8g@mail.gmail.com/

The handling of
CAMZ6RqLHEoukxDfV33iDWXjM1baK922QnWSkOP01VzZ0S_9H8g@mail.gmail.com in v5
was better, but there were some questions by Vincent...

So let's continue the discussion from v5 here:

> > +static void nct6694_can_handle_state_change(struct net_device *ndev,
> > +                                           u8 status)
> > +{
> > +       struct nct6694_can_priv *priv = netdev_priv(ndev);
> > +       enum can_state new_state = priv->can.state;
> > +       enum can_state rx_state, tx_state;
> > +       struct can_berr_counter bec;
> > +       struct can_frame *cf;
> > +       struct sk_buff *skb;
> > +
> > +       nct6694_can_get_berr_counter(ndev, &bec);
> > +       can_state_get_by_berr_counter(ndev, &bec, &tx_state, &rx_state);
> 
> Here, you set up tx_state and rx_state...
> 

remove the switch (status)...

> > +       switch (status) {
> > +       case NCT6694_CAN_EVT_STS_ERROR_ACTIVE:
> > +               new_state = CAN_STATE_ERROR_ACTIVE;
> > +               break;
> > +       case NCT6694_CAN_EVT_STS_ERROR_PASSIVE:
> > +               new_state = CAN_STATE_ERROR_PASSIVE;
> > +               break;
> > +       case NCT6694_CAN_EVT_STS_BUS_OFF:
> > +               new_state = CAN_STATE_BUS_OFF;
> > +               break;
> > +       case NCT6694_CAN_EVT_STS_WARNING:
> > +               new_state = CAN_STATE_ERROR_WARNING;
> > +               break;
> > +       default:
> > +               netdev_err(ndev, "Receive unknown CAN status event.\n");
> > +               return;
> > +       }

replace it by:

	new_state = max(tx_state, rx_state);

> > +
> > +       /* state hasn't changed */
> > +       if (new_state == priv->can.state)
> > +               return;
> > +
> > +       skb = alloc_can_err_skb(ndev, &cf);
> > +

remove this VVV
> > +       tx_state = bec.txerr >= bec.rxerr ? new_state : 0;
> > +       rx_state = bec.txerr <= bec.rxerr ? new_state : 0;
            ^^^

> 
> ... but you never used the values returned by
> can_state_get_by_berr_counter() and just overwrote the tx and rx
> state.
> 
> What is the logic here? Why do you need to manually adjust those two
> values? Isn't the logic in can_change_state() sufficient?
> 
> > +       can_change_state(ndev, cf, tx_state, rx_state);
> > +
> > +       if (new_state == CAN_STATE_BUS_OFF) {

if (priv->can.state == CAN_STATE_BUS_OFF) {

> 
> Same for the new_state. The function can_change_state() calculate the
> new state from tx_state and rx_state and save it under
> can_priv->state. But here, you do your own calculation.
> 
> Only keep one of the two. If your device already tells you the state,
> then fine! Just use the information from your device and do not use
> can_change_state(). Here, you are doing double work resulting in a
> weird mix.
>

what does your device do when it goes into bus off?

> > +               can_bus_off(ndev);
> > +       } else if (skb) {
> > +               cf->can_id |= CAN_ERR_CNT;
> > +               cf->data[6] = bec.txerr;
> > +               cf->data[7] = bec.rxerr;
> > +       }
> > +

if (skb)

> > +       nct6694_can_rx_offload(&priv->offload, skb);
> > +}

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

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Re: [PATCH v7 7/7] rtc: Add Nuvoton NCT6694 RTC support

[Alexandre Belloni]

On 07/02/2025 15:45:02+0800, Ming Yu wrote:
> This driver supports RTC functionality for NCT6694 MFD device
> based on USB interface.
> 
> Signed-off-by: Ming Yu <a0282524688@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> ---
>  MAINTAINERS               |   1 +
>  drivers/rtc/Kconfig       |  10 ++
>  drivers/rtc/Makefile      |   1 +
>  drivers/rtc/rtc-nct6694.c | 286 ++++++++++++++++++++++++++++++++++++++
>  4 files changed, 298 insertions(+)
>  create mode 100644 drivers/rtc/rtc-nct6694.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a9eda4530b07..7eba4ffdc877 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16927,6 +16927,7 @@ F:	drivers/hwmon/nct6694-hwmon.c
>  F:	drivers/i2c/busses/i2c-nct6694.c
>  F:	drivers/mfd/nct6694.c
>  F:	drivers/net/can/usb/nct6694_canfd.c
> +F:	drivers/rtc/rtc-nct6694.c
>  F:	drivers/watchdog/nct6694_wdt.c
>  F:	include/linux/mfd/nct6694.h
>  
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 0bbbf778ecfa..248425bf26f3 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -416,6 +416,16 @@ config RTC_DRV_NCT3018Y
>  	   This driver can also be built as a module, if so, the module will be
>  	   called "rtc-nct3018y".
>  
> +config RTC_DRV_NCT6694
> +	tristate "Nuvoton NCT6694 RTC support"
> +	depends on MFD_NCT6694
> +	help
> +	  If you say yes to this option, support will be included for Nuvoton
> +	  NCT6694, a USB device to RTC.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called rtc-nct6694.
> +
>  config RTC_DRV_RK808
>  	tristate "Rockchip RK805/RK808/RK809/RK817/RK818 RTC"
>  	depends on MFD_RK8XX
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 489b4ab07068..d0d6f4a4972e 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -118,6 +118,7 @@ obj-$(CONFIG_RTC_DRV_MXC)	+= rtc-mxc.o
>  obj-$(CONFIG_RTC_DRV_MXC_V2)	+= rtc-mxc_v2.o
>  obj-$(CONFIG_RTC_DRV_GAMECUBE)	+= rtc-gamecube.o
>  obj-$(CONFIG_RTC_DRV_NCT3018Y)	+= rtc-nct3018y.o
> +obj-$(CONFIG_RTC_DRV_NCT6694)	+= rtc-nct6694.o
>  obj-$(CONFIG_RTC_DRV_NTXEC)	+= rtc-ntxec.o
>  obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o
>  obj-$(CONFIG_RTC_DRV_OPAL)	+= rtc-opal.o
> diff --git a/drivers/rtc/rtc-nct6694.c b/drivers/rtc/rtc-nct6694.c
> new file mode 100644
> index 000000000000..892674d453d1
> --- /dev/null
> +++ b/drivers/rtc/rtc-nct6694.c
> @@ -0,0 +1,286 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Nuvoton NCT6694 RTC driver based on USB interface.
> + *
> + * Copyright (C) 2024 Nuvoton Technology Corp.
> + */
> +
> +#include <linux/bcd.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/nct6694.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/rtc.h>
> +#include <linux/slab.h>
> +
> +/*
> + * USB command module type for NCT6694 RTC controller.
> + * This defines the module type used for communication with the NCT6694
> + * RTC controller over the USB interface.
> + */
> +#define NCT6694_RTC_MOD		0x08
> +
> +/* Command 00h - RTC Time */
> +#define NCT6694_RTC_TIME	0x0000
> +#define NCT6694_RTC_TIME_SEL	0x00
> +
> +/* Command 01h - RTC Alarm */
> +#define NCT6694_RTC_ALARM	0x01
> +#define NCT6694_RTC_ALARM_SEL	0x00
> +
> +/* Command 02h - RTC Status */
> +#define NCT6694_RTC_STATUS	0x02
> +#define NCT6694_RTC_STATUS_SEL	0x00
> +
> +#define NCT6694_RTC_IRQ_INT_EN	BIT(0)	/* Transmit a USB INT-in when RTC alarm */
> +#define NCT6694_RTC_IRQ_GPO_EN	BIT(5)	/* Trigger a GPO Low Pulse when RTC alarm */
> +
> +#define NCT6694_RTC_IRQ_EN	(NCT6694_RTC_IRQ_INT_EN | NCT6694_RTC_IRQ_GPO_EN)
> +#define NCT6694_RTC_IRQ_STS	BIT(0)	/* Write 1 clear IRQ status */
> +
> +struct __packed nct6694_rtc_time {
> +	u8 sec;
> +	u8 min;
> +	u8 hour;
> +	u8 week;
> +	u8 day;
> +	u8 month;
> +	u8 year;
> +};
> +
> +struct __packed nct6694_rtc_alarm {
> +	u8 sec;
> +	u8 min;
> +	u8 hour;
> +	u8 alarm_en;
> +	u8 alarm_pend;
> +};
> +
> +struct __packed nct6694_rtc_status {
> +	u8 irq_en;
> +	u8 irq_pend;
> +};
> +
> +union __packed nct6694_rtc_msg {
> +	struct nct6694_rtc_time time;
> +	struct nct6694_rtc_alarm alarm;
> +	struct nct6694_rtc_status sts;
> +};
> +
> +struct nct6694_rtc_data {
> +	struct nct6694 *nct6694;
> +	struct rtc_device *rtc;
> +	union nct6694_rtc_msg *msg;
> +};
> +
> +static int nct6694_rtc_read_time(struct device *dev, struct rtc_time *tm)
> +{
> +	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
> +	struct nct6694_rtc_time *time = &data->msg->time;
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_RTC_MOD,
> +		.cmd = NCT6694_RTC_TIME,
> +		.sel = NCT6694_RTC_TIME_SEL,
> +		.len = cpu_to_le16(sizeof(*time))
> +	};
> +	int ret;
> +
> +	ret = nct6694_read_msg(data->nct6694, &cmd_hd, time);
> +	if (ret)
> +		return ret;
> +
> +	tm->tm_sec = bcd2bin(time->sec);		/* tm_sec expect 0 ~ 59 */
> +	tm->tm_min = bcd2bin(time->min);		/* tm_min expect 0 ~ 59 */
> +	tm->tm_hour = bcd2bin(time->hour);		/* tm_hour expect 0 ~ 23 */
> +	tm->tm_wday = bcd2bin(time->week) - 1;		/* tm_wday expect 0 ~ 6 */
> +	tm->tm_mday = bcd2bin(time->day);		/* tm_mday expect 1 ~ 31 */
> +	tm->tm_mon = bcd2bin(time->month) - 1;		/* tm_month expect 0 ~ 11 */
> +	tm->tm_year = bcd2bin(time->year) + 100;	/* tm_year expect since 1900 */
> +
> +	return ret;
> +}
> +
> +static int nct6694_rtc_set_time(struct device *dev, struct rtc_time *tm)
> +{
> +	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
> +	struct nct6694_rtc_time *time = &data->msg->time;
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_RTC_MOD,
> +		.cmd = NCT6694_RTC_TIME,
> +		.sel = NCT6694_RTC_TIME_SEL,
> +		.len = cpu_to_le16(sizeof(*time))
> +	};
> +
> +	time->sec = bin2bcd(tm->tm_sec);
> +	time->min = bin2bcd(tm->tm_min);
> +	time->hour = bin2bcd(tm->tm_hour);
> +	time->week = bin2bcd(tm->tm_wday + 1);
> +	time->day = bin2bcd(tm->tm_mday);
> +	time->month = bin2bcd(tm->tm_mon + 1);
> +	time->year = bin2bcd(tm->tm_year - 100);
> +
> +	return nct6694_write_msg(data->nct6694, &cmd_hd, time);
> +}
> +
> +static int nct6694_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
> +	struct nct6694_rtc_alarm *alarm = &data->msg->alarm;
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_RTC_MOD,
> +		.cmd = NCT6694_RTC_ALARM,
> +		.sel = NCT6694_RTC_ALARM_SEL,
> +		.len = cpu_to_le16(sizeof(*alarm))
> +	};
> +	int ret;
> +
> +	ret = nct6694_read_msg(data->nct6694, &cmd_hd, alarm);
> +	if (ret)
> +		return ret;
> +
> +	alrm->time.tm_sec = bcd2bin(alarm->sec);
> +	alrm->time.tm_min = bcd2bin(alarm->min);
> +	alrm->time.tm_hour = bcd2bin(alarm->hour);
> +	alrm->enabled = alarm->alarm_en;
> +	alrm->pending = alarm->alarm_pend;
> +
> +	return ret;
> +}
> +
> +static int nct6694_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
> +	struct nct6694_rtc_alarm *alarm = &data->msg->alarm;
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_RTC_MOD,
> +		.cmd = NCT6694_RTC_ALARM,
> +		.sel = NCT6694_RTC_ALARM_SEL,
> +		.len = cpu_to_le16(sizeof(*alarm))
> +	};
> +
> +	alarm->sec = bin2bcd(alrm->time.tm_sec);
> +	alarm->min = bin2bcd(alrm->time.tm_min);
> +	alarm->hour = bin2bcd(alrm->time.tm_hour);
> +	alarm->alarm_en = alrm->enabled ? NCT6694_RTC_IRQ_EN : 0;
> +	alarm->alarm_pend = 0;
> +
> +	return nct6694_write_msg(data->nct6694, &cmd_hd, alarm);
> +}
> +
> +static int nct6694_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
> +{
> +	struct nct6694_rtc_data *data = dev_get_drvdata(dev);
> +	struct nct6694_rtc_status *sts = &data->msg->sts;
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_RTC_MOD,
> +		.cmd = NCT6694_RTC_STATUS,
> +		.sel = NCT6694_RTC_STATUS_SEL,
> +		.len = cpu_to_le16(sizeof(*sts))
> +	};
> +
> +	if (enabled)
> +		sts->irq_en |= NCT6694_RTC_IRQ_EN;
> +	else
> +		sts->irq_en &= ~NCT6694_RTC_IRQ_EN;
> +
> +	sts->irq_pend = 0;
> +
> +	return nct6694_write_msg(data->nct6694, &cmd_hd, sts);
> +}
> +
> +static const struct rtc_class_ops nct6694_rtc_ops = {
> +	.read_time = nct6694_rtc_read_time,
> +	.set_time = nct6694_rtc_set_time,
> +	.read_alarm = nct6694_rtc_read_alarm,
> +	.set_alarm = nct6694_rtc_set_alarm,
> +	.alarm_irq_enable = nct6694_rtc_alarm_irq_enable,
> +};
> +
> +static irqreturn_t nct6694_irq(int irq, void *dev_id)
> +{
> +	struct nct6694_rtc_data *data = dev_id;
> +	struct nct6694_rtc_status *sts = &data->msg->sts;
> +	static const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_RTC_MOD,
> +		.cmd = NCT6694_RTC_STATUS,
> +		.sel = NCT6694_RTC_STATUS_SEL,
> +		.len = cpu_to_le16(sizeof(*sts))
> +	};
> +	int ret;
> +
> +	rtc_lock(data->rtc);
> +
> +	sts->irq_en = NCT6694_RTC_IRQ_EN;
> +	sts->irq_pend = NCT6694_RTC_IRQ_STS;
> +	ret = nct6694_write_msg(data->nct6694, &cmd_hd, sts);
> +	if (ret) {
> +		rtc_unlock(data->rtc);
> +		return IRQ_NONE;
> +	}
> +
> +	rtc_update_irq(data->rtc, 1, RTC_IRQF | RTC_AF);
> +
> +	rtc_unlock(data->rtc);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int nct6694_rtc_probe(struct platform_device *pdev)
> +{
> +	struct nct6694_rtc_data *data;
> +	struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent);
> +	int ret, irq;
> +
> +	irq = irq_create_mapping(nct6694->domain, NCT6694_IRQ_RTC);
> +	if (!irq)
> +		return -EINVAL;
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->msg = devm_kzalloc(&pdev->dev, sizeof(union nct6694_rtc_msg),
> +				 GFP_KERNEL);
> +	if (!data->msg)
> +		return -ENOMEM;
> +
> +	data->rtc = devm_rtc_allocate_device(&pdev->dev);
> +	if (IS_ERR(data->rtc))
> +		return PTR_ERR(data->rtc);
> +
> +	data->nct6694 = nct6694;
> +	data->rtc->ops = &nct6694_rtc_ops;
> +	data->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
> +	data->rtc->range_max = RTC_TIMESTAMP_END_2099;
> +
> +	platform_set_drvdata(pdev, data);
> +
> +	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
> +					nct6694_irq, IRQF_ONESHOT,
> +					"rtc-nct6694", data);
> +	if (ret < 0)
> +		return dev_err_probe(&pdev->dev, ret, "Failed to request irq\n");
> +
> +	ret = devm_rtc_register_device(data->rtc);
> +	if (ret)
> +		return ret;
> +
> +	device_init_wakeup(&pdev->dev, true);
> +	return 0;
> +}
> +
> +static struct platform_driver nct6694_rtc_driver = {
> +	.driver = {
> +		.name	= "rtc-nct6694",
> +	},
> +	.probe		= nct6694_rtc_probe,
> +};
> +
> +module_platform_driver(nct6694_rtc_driver);
> +
> +MODULE_DESCRIPTION("USB-RTC driver for NCT6694");
> +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:nct6694-rtc");
> -- 
> 2.34.1
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com