* [PATCH v8 06/13] mfd: nct6694: Move module type macros to shared header
[not found] <20261007092102.3768818-1-a0282524688@gmail.com>
2026-10-07 9:20 ` [PATCH v8 01/13] gpio: nct6694: Mark the GPIO controller as sleeping a0282524688
@ 2026-10-07 9:20 ` a0282524688
2026-10-07 9:28 ` sashiko-bot
2026-10-11 5:30 ` Andi Shyti
2026-10-07 9:21 ` [PATCH v8 11/13] mfd: nct6694: Introduce regmap-based transport abstraction a0282524688
2 siblings, 2 replies; 6+ messages in thread
From: a0282524688 @ 2026-10-07 9:20 UTC (permalink / raw)
To: lee, Ming Yu, Linus Walleij, Bartosz Golaszewski, Guenter Roeck,
Andi Shyti, Marc Kleine-Budde, Vincent Mailhol, Alexandre Belloni,
Wim Van Sebroeck
Cc: linux-kernel, Ming Yu, linux-gpio, linux-hwmon, linux-i2c,
linux-can, linux-rtc, linux-watchdog, mfd
From: Ming Yu <a0282524688@gmail.com>
Each sub-device driver defines the module type used by its own
commands. The upcoming HIF transport also needs to recognise
NCT6694_RPT_MOD, as report accesses are served from a separate
register space rather than through the command mailbox.
Move all module types into the shared header so that the transports
and the sub-device drivers use a single set of definitions.
No functional change.
Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
Changes in v8:
- Reworded the commit message to explain why the transport needs the
module types.
Changes in v7:
- None.
Changes in v6:
- None.
Changes in v5:
- Split from the monolithic v4 patch to follow the single logical change
principle.
drivers/gpio/gpio-nct6694.c | 7 -------
drivers/hwmon/nct6694-hwmon.c | 21 ---------------------
drivers/i2c/busses/i2c-nct6694.c | 7 -------
drivers/net/can/usb/nct6694_canfd.c | 6 ------
drivers/rtc/rtc-nct6694.c | 7 -------
drivers/watchdog/nct6694_wdt.c | 7 -------
include/linux/mfd/nct6694.h | 9 +++++++++
7 files changed, 9 insertions(+), 55 deletions(-)
diff --git a/drivers/gpio/gpio-nct6694.c b/drivers/gpio/gpio-nct6694.c
index a38add1cde29..c8cdf4520466 100644
--- a/drivers/gpio/gpio-nct6694.c
+++ b/drivers/gpio/gpio-nct6694.c
@@ -13,13 +13,6 @@
#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
diff --git a/drivers/hwmon/nct6694-hwmon.c b/drivers/hwmon/nct6694-hwmon.c
index 9a9a4db434c4..bd4c106305c7 100644
--- a/drivers/hwmon/nct6694-hwmon.c
+++ b/drivers/hwmon/nct6694-hwmon.c
@@ -15,13 +15,6 @@
#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
@@ -38,13 +31,6 @@
#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
@@ -53,13 +39,6 @@
#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
diff --git a/drivers/i2c/busses/i2c-nct6694.c b/drivers/i2c/busses/i2c-nct6694.c
index 1413ab6f9462..ef3329f34246 100644
--- a/drivers/i2c/busses/i2c-nct6694.c
+++ b/drivers/i2c/busses/i2c-nct6694.c
@@ -12,13 +12,6 @@
#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
diff --git a/drivers/net/can/usb/nct6694_canfd.c b/drivers/net/can/usb/nct6694_canfd.c
index e5f7f8849a73..262b4c26c9d4 100644
--- a/drivers/net/can/usb/nct6694_canfd.c
+++ b/drivers/net/can/usb/nct6694_canfd.c
@@ -18,12 +18,6 @@
#define DEVICE_NAME "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_CANFD_MOD 0x05
-
/* Command 00h - CAN Setting and Initialization */
#define NCT6694_CANFD_SETTING 0x00
#define NCT6694_CANFD_SETTING_ACTIVE_CTRL1 BIT(0)
diff --git a/drivers/rtc/rtc-nct6694.c b/drivers/rtc/rtc-nct6694.c
index 35401a0d9cf5..c06902f150c9 100644
--- a/drivers/rtc/rtc-nct6694.c
+++ b/drivers/rtc/rtc-nct6694.c
@@ -14,13 +14,6 @@
#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
diff --git a/drivers/watchdog/nct6694_wdt.c b/drivers/watchdog/nct6694_wdt.c
index bc3689bd4b6b..4c06ac105562 100644
--- a/drivers/watchdog/nct6694_wdt.c
+++ b/drivers/watchdog/nct6694_wdt.c
@@ -20,13 +20,6 @@
#define NCT6694_WDT_MAX_DEVS 2
-/*
- * 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)
diff --git a/include/linux/mfd/nct6694.h b/include/linux/mfd/nct6694.h
index 69e4652cf16c..d46ae34a497e 100644
--- a/include/linux/mfd/nct6694.h
+++ b/include/linux/mfd/nct6694.h
@@ -8,6 +8,15 @@
#ifndef __MFD_NCT6694_H
#define __MFD_NCT6694_H
+#define NCT6694_HWMON_MOD 0x00
+#define NCT6694_PWM_MOD 0x01
+#define NCT6694_I2C_MOD 0x03
+#define NCT6694_CANFD_MOD 0x05
+#define NCT6694_WDT_MOD 0x07
+#define NCT6694_RTC_MOD 0x08
+#define NCT6694_RPT_MOD 0xFF
+#define NCT6694_GPIO_MOD NCT6694_RPT_MOD
+
#define NCT6694_VENDOR_ID 0x0416
#define NCT6694_PRODUCT_ID 0x200B
#define NCT6694_INT_IN_EP 0x01
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v8 11/13] mfd: nct6694: Introduce regmap-based transport abstraction
[not found] <20261007092102.3768818-1-a0282524688@gmail.com>
2026-10-07 9:20 ` [PATCH v8 01/13] gpio: nct6694: Mark the GPIO controller as sleeping a0282524688
2026-10-07 9:20 ` [PATCH v8 06/13] mfd: nct6694: Move module type macros to shared header a0282524688
@ 2026-10-07 9:21 ` a0282524688
2026-10-11 5:39 ` Andi Shyti
2 siblings, 1 reply; 6+ messages in thread
From: a0282524688 @ 2026-10-07 9:21 UTC (permalink / raw)
To: lee, Ming Yu, Andi Shyti; +Cc: linux-kernel, Ming Yu, linux-i2c, mfd
From: Ming Yu <a0282524688@gmail.com>
Sub-device drivers call into the USB transport directly, so a second
transport cannot be added without touching all of them.
Wrap the transport behind a regmap bus. The command header is mapped
onto a single 32-bit register by packing the host control byte, the
module id and the 16-bit offset, so that the sub-device drivers can use
the regmap bulk accessors. The access_lock is dropped as regmap already
serialises the bus accesses.
Add nct6694_write_read_msg() for the commands that send a request and
read the reply back in the same firmware message, and use it for the
I2C deliver command.
Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
Changes in v8:
- Renamed the transport buffer arguments to tx_buf/rx_buf.
- Dropped max_raw_read/max_raw_write from the regmap_config, as they
are ignored when a regmap_bus is provided.
Changes in v7:
- Made the USB transport helpers static and gave nct6694_usb_write_msg()
separate @tx/@rx buffers, so a SET command only copies the firmware
reply back when the caller asks for it.
- Documented in the shared header why nct6694_write_read_msg() is
expressed as a read of a SET register.
Changes in v6:
- New patch. Replaces the v5 function-pointer abstraction with a
regmap_bus based transport: the firmware command header is packed into
a single 32-bit regmap register and sub-device drivers use the regmap
bulk accessors. Adds nct6694_write_read_msg() for request/response
commands and drops the per-transport access_lock (regmap already
serialises bus accesses).
drivers/i2c/busses/i2c-nct6694.c | 2 +-
drivers/mfd/Kconfig | 1 +
drivers/mfd/nct6694-usb.c | 102 ++++++++++++++++++-------------
include/linux/mfd/nct6694.h | 53 +++++++++++++---
4 files changed, 108 insertions(+), 50 deletions(-)
diff --git a/drivers/i2c/busses/i2c-nct6694.c b/drivers/i2c/busses/i2c-nct6694.c
index ef3329f34246..7e32dab6e759 100644
--- a/drivers/i2c/busses/i2c-nct6694.c
+++ b/drivers/i2c/busses/i2c-nct6694.c
@@ -77,7 +77,7 @@ static int nct6694_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int
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);
+ ret = nct6694_write_read_msg(data->nct6694, &cmd_hd, deliver);
if (ret < 0)
return ret;
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index e4fd4572472f..a0d9d6ccfb0c 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1166,6 +1166,7 @@ config MFD_MENF21BMC
config MFD_NCT6694
tristate "Nuvoton NCT6694 support"
select MFD_CORE
+ select REGMAP
depends on USB
help
This enables support for the Nuvoton USB device NCT6694, which shares
diff --git a/drivers/mfd/nct6694-usb.c b/drivers/mfd/nct6694-usb.c
index 455eeed62dce..636721f277a0 100644
--- a/drivers/mfd/nct6694-usb.c
+++ b/drivers/mfd/nct6694-usb.c
@@ -9,6 +9,7 @@
* CAN, WDT, HWMON and RTC management.
*/
+#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
@@ -17,7 +18,9 @@
#include <linux/mfd/core.h>
#include <linux/mfd/nct6694.h>
#include <linux/module.h>
+#include <linux/regmap.h>
#include <linux/slab.h>
+#include <linux/unaligned.h>
#include <linux/usb.h>
#define NCT6694_VENDOR_ID 0x0416
@@ -35,7 +38,6 @@ union __packed nct6694_usb_hdr {
struct nct6694_usb_data {
struct nct6694 core;
- struct mutex access_lock;
struct usb_device *usb_dev;
struct urb *int_urb;
union nct6694_usb_hdr *hdr_buf;
@@ -108,21 +110,9 @@ static int nct6694_usb_err_handling(struct nct6694 *ddata, unsigned char err_sta
return -EIO;
}
-/**
- * nct6694_usb_read_msg() - Read message from NCT6694 device
- * @ddata: NCT6694 device pointer
- * @cmd_hd: command header structure
- * @buf: buffer to store the response data
- *
- * Sends a command to the NCT6694 device and reads the response.
- * The command header is specified in @cmd_hd, and the response
- * data is stored in @buf.
- *
- * Return: Negative value on error or 0 on success.
- */
-int nct6694_usb_read_msg(struct nct6694 *ddata,
- const struct nct6694_cmd_header *cmd_hd,
- void *buf)
+static int nct6694_usb_read_msg(struct nct6694 *ddata,
+ const struct nct6694_cmd_header *cmd_hd,
+ void *rx_buf)
{
struct nct6694_usb_data *usb_data = to_nct6694_usb_data(ddata);
union nct6694_usb_hdr *hdr = usb_data->hdr_buf;
@@ -133,8 +123,6 @@ int nct6694_usb_read_msg(struct nct6694 *ddata,
if (data_len > NCT6694_MAX_DATA_LEN)
return -EINVAL;
- guard(mutex)(&usb_data->access_lock);
-
memcpy(&hdr->cmd_header, cmd_hd, sizeof(*cmd_hd));
hdr->cmd_header.hctrl = NCT6694_HCTRL_GET;
@@ -168,26 +156,15 @@ int nct6694_usb_read_msg(struct nct6694 *ddata,
return -EIO;
}
- memcpy(buf, usb_data->data_buf, data_len);
+ memcpy(rx_buf, usb_data->data_buf, data_len);
return nct6694_usb_err_handling(ddata, hdr->response_header.sts);
}
-EXPORT_SYMBOL_GPL(nct6694_usb_read_msg);
-/**
- * nct6694_usb_write_msg() - Write message to NCT6694 device
- * @ddata: NCT6694 device pointer
- * @cmd_hd: command header structure
- * @buf: buffer containing the data to be sent
- *
- * Sends a command to the NCT6694 device and writes the data
- * from @buf. The command header is specified in @cmd_hd.
- *
- * Return: Negative value on error or 0 on success.
- */
-int nct6694_usb_write_msg(struct nct6694 *ddata,
- const struct nct6694_cmd_header *cmd_hd,
- void *buf)
+/* @rx_buf may be NULL when the reply to the SET command is not needed */
+static int nct6694_usb_write_msg(struct nct6694 *ddata,
+ const struct nct6694_cmd_header *cmd_hd,
+ const void *tx_buf, void *rx_buf)
{
struct nct6694_usb_data *usb_data = to_nct6694_usb_data(ddata);
union nct6694_usb_hdr *hdr = usb_data->hdr_buf;
@@ -198,11 +175,9 @@ int nct6694_usb_write_msg(struct nct6694 *ddata,
if (data_len > NCT6694_MAX_DATA_LEN)
return -EINVAL;
- guard(mutex)(&usb_data->access_lock);
-
memcpy(&hdr->cmd_header, cmd_hd, sizeof(*cmd_hd));
hdr->cmd_header.hctrl = NCT6694_HCTRL_SET;
- memcpy(usb_data->data_buf, buf, data_len);
+ memcpy(usb_data->data_buf, tx_buf, data_len);
/* Send command packet to USB device */
ret = usb_bulk_msg(usb_dev, usb_sndbulkpipe(usb_dev, NCT6694_BULK_OUT_EP),
@@ -240,11 +215,53 @@ int nct6694_usb_write_msg(struct nct6694 *ddata,
return -EIO;
}
- memcpy(buf, usb_data->data_buf, data_len);
+ if (rx_buf)
+ memcpy(rx_buf, usb_data->data_buf, data_len);
return nct6694_usb_err_handling(ddata, hdr->response_header.sts);
}
-EXPORT_SYMBOL_GPL(nct6694_usb_write_msg);
+
+static int nct6694_usb_regmap_read(void *context, const void *reg_buf,
+ size_t reg_size, void *val_buf,
+ size_t val_size)
+{
+ struct nct6694 *ddata = context;
+ u32 reg = get_unaligned_be32(reg_buf);
+ const struct nct6694_cmd_header cmd_hd = {
+ .mod = FIELD_GET(NCT6694_REG_MOD, reg),
+ .offset = cpu_to_le16(FIELD_GET(NCT6694_REG_OFFSET, reg)),
+ .len = cpu_to_le16(val_size),
+ };
+
+ if (FIELD_GET(NCT6694_REG_HCTRL, reg) == NCT6694_HCTRL_SET)
+ return nct6694_usb_write_msg(ddata, &cmd_hd, val_buf, val_buf);
+
+ return nct6694_usb_read_msg(ddata, &cmd_hd, val_buf);
+}
+
+static int nct6694_usb_regmap_write(void *context, const void *data,
+ size_t count)
+{
+ struct nct6694 *ddata = context;
+ u32 reg = get_unaligned_be32(data);
+ const struct nct6694_cmd_header cmd_hd = {
+ .mod = FIELD_GET(NCT6694_REG_MOD, reg),
+ .offset = cpu_to_le16(FIELD_GET(NCT6694_REG_OFFSET, reg)),
+ .len = cpu_to_le16(count - sizeof(reg)),
+ };
+
+ return nct6694_usb_write_msg(ddata, &cmd_hd, data + sizeof(reg), NULL);
+}
+
+static const struct regmap_bus nct6694_usb_regmap_bus = {
+ .read = nct6694_usb_regmap_read,
+ .write = nct6694_usb_regmap_write,
+};
+
+static const struct regmap_config nct6694_usb_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 8,
+};
static void nct6694_usb_int_callback(struct urb *urb)
{
@@ -329,9 +346,12 @@ static int nct6694_usb_probe(struct usb_interface *iface,
ddata->dev = dev;
usb_data->usb_dev = usb_dev;
- ret = devm_mutex_init(dev, &usb_data->access_lock);
- if (ret)
+ ddata->regmap = devm_regmap_init(dev, &nct6694_usb_regmap_bus, ddata,
+ &nct6694_usb_regmap_config);
+ if (IS_ERR(ddata->regmap)) {
+ ret = PTR_ERR(ddata->regmap);
goto err_free_urb;
+ }
int_pipe = usb_rcvintpipe(usb_dev, NCT6694_INT_IN_EP);
usb_fill_int_urb(usb_data->int_urb, usb_dev, int_pipe,
diff --git a/include/linux/mfd/nct6694.h b/include/linux/mfd/nct6694.h
index 03296132ad34..1593806d34fd 100644
--- a/include/linux/mfd/nct6694.h
+++ b/include/linux/mfd/nct6694.h
@@ -9,6 +9,9 @@
#ifndef __MFD_NCT6694_H
#define __MFD_NCT6694_H
+#include <linux/bitfield.h>
+#include <linux/regmap.h>
+
#define NCT6694_HWMON_MOD 0x00
#define NCT6694_PWM_MOD 0x01
#define NCT6694_I2C_MOD 0x03
@@ -82,6 +85,7 @@ struct __packed nct6694_response_header {
struct nct6694 {
struct device *dev;
+ struct regmap *regmap;
struct ida gpio_ida;
struct ida i2c_ida;
struct ida canfd_ida;
@@ -94,25 +98,58 @@ struct nct6694 {
int nct6694_device_init(struct device *dev);
void nct6694_device_exit(struct device *dev);
-int nct6694_usb_read_msg(struct nct6694 *ddata,
- const struct nct6694_cmd_header *cmd_hd,
- void *buf);
-int nct6694_usb_write_msg(struct nct6694 *ddata,
- const struct nct6694_cmd_header *cmd_hd,
- void *buf);
+/*
+ * Each firmware command is mapped to a single 32-bit regmap register, so that
+ * the sub-device drivers use the regmap bulk accessors and each transport only
+ * implements a regmap bus:
+ *
+ * bits [31:24] host control (NCT6694_HCTRL_GET / NCT6694_HCTRL_SET)
+ * bits [23:16] module id
+ * bits [15:0] offset (low byte = command, high byte = selector)
+ */
+#define NCT6694_REG_HCTRL GENMASK(31, 24)
+#define NCT6694_REG_MOD GENMASK(23, 16)
+#define NCT6694_REG_OFFSET GENMASK(15, 0)
+
+static inline u32 nct6694_cmd_to_reg(const struct nct6694_cmd_header *cmd_hd,
+ u8 hctrl)
+{
+ return FIELD_PREP(NCT6694_REG_HCTRL, hctrl) |
+ FIELD_PREP(NCT6694_REG_MOD, cmd_hd->mod) |
+ FIELD_PREP(NCT6694_REG_OFFSET, le16_to_cpu(cmd_hd->offset));
+}
static inline int nct6694_read_msg(struct nct6694 *ddata,
const struct nct6694_cmd_header *cmd_hd,
void *buf)
{
- return nct6694_usb_read_msg(ddata, cmd_hd, buf);
+ return regmap_bulk_read(ddata->regmap,
+ nct6694_cmd_to_reg(cmd_hd, NCT6694_HCTRL_GET),
+ buf, le16_to_cpu(cmd_hd->len));
}
static inline int nct6694_write_msg(struct nct6694 *ddata,
const struct nct6694_cmd_header *cmd_hd,
void *buf)
{
- return nct6694_usb_write_msg(ddata, cmd_hd, buf);
+ return regmap_bulk_write(ddata->regmap,
+ nct6694_cmd_to_reg(cmd_hd, NCT6694_HCTRL_SET),
+ buf, le16_to_cpu(cmd_hd->len));
+}
+
+/*
+ * Some commands, such as the I2C deliver, send a request and read the reply
+ * back in the same firmware message. Express this as a read of a SET register:
+ * @buf holds the request on entry and the reply on return. This relies on the
+ * regmap being uncached and byte sized, so that @buf reaches the bus as is.
+ */
+static inline int nct6694_write_read_msg(struct nct6694 *ddata,
+ const struct nct6694_cmd_header *cmd_hd,
+ void *buf)
+{
+ return regmap_bulk_read(ddata->regmap,
+ nct6694_cmd_to_reg(cmd_hd, NCT6694_HCTRL_SET),
+ buf, le16_to_cpu(cmd_hd->len));
}
#endif
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread