[PATCH v4 0/3] usb/gpio/i2c: Add Intel USBIO USB IO-expander drivers

[PATCH v4 0/3] usb/gpio/i2c: Add Intel USBIO USB IO-expander drivers

[Hans de Goede]

Hi All,

Here is v4 of the patch series to add support for the Intel USBIO USB
IO-expander used by the MIPI cameras on various new (Meteor Lake and later)
Intel laptops.

Changes in v4:
- GPIO: Drop include <linux/dev_printk.h>, unneeded auxiliary_set_drvdata()

Changes in v3:
- Drop (offset >= gc->ngpio) check and make usbio_gpio_get_bank_and_pin()
  return void
- Propagate usbio_gpio_set() ret val in usbio_gpio_direction_output()
- Use devm_gpiochip_add_data() and drop auxiliary_driver remove() callback

Changes in v2:
- Split usbio-bridge mutex into ctrl_mutex and bulk_mutex
- Drop SPI support since this is not used on devices in the field
- Rework disconnect handling to be more robust
- Several different revisions need special casing add a quirks mechanism
  for this
- Stop using stdint.h (uintX_t) types
- Use __le16, __le32 type + cpu_to_le16() and friends for on wire words
- Properly check auxiliary_device_add() return value
- Add a mutex to the GPIO driver to protect usbio_gpio_update_config()
  calls, which read-modify-write banks[x].config, racing with each other
- Adjust usbio_gpio_get() to have an int return value and propagate the
  usbio_control_msg() return value
- Various (small) style fixes from Sakari's review of all 3 patches

The first patch adds an USB bridge driver which registers auxbus children
for the GPIO and I2C functions of the USBIO chip.

The second and third patch add a GPIO resp. an I2C driver for the
auxbus children using the IO functions exported by the USB bridge driver.

The second and third patch depend on the IO functions exported by
the first patch. So to merge this we will need either an immutable tag on
the USB tree, or all 3 patches can be merged through the USB tree with
acks from the GPIO and I2C subsystem maintainers.

Regards,

Hans


Israel Cepeda (3):
  usb: misc: Add Intel USBIO bridge driver
  gpio: Add Intel USBIO GPIO driver
  i2c: Add Intel USBIO I2C driver

 MAINTAINERS                    |  10 +
 drivers/gpio/Kconfig           |  11 +
 drivers/gpio/Makefile          |   1 +
 drivers/gpio/gpio-usbio.c      | 247 +++++++++++
 drivers/i2c/busses/Kconfig     |  11 +
 drivers/i2c/busses/Makefile    |   1 +
 drivers/i2c/busses/i2c-usbio.c | 325 ++++++++++++++
 drivers/usb/misc/Kconfig       |  14 +
 drivers/usb/misc/Makefile      |   1 +
 drivers/usb/misc/usbio.c       | 749 +++++++++++++++++++++++++++++++++
 include/linux/usb/usbio.h      | 177 ++++++++
 11 files changed, 1547 insertions(+)
 create mode 100644 drivers/gpio/gpio-usbio.c
 create mode 100644 drivers/i2c/busses/i2c-usbio.c
 create mode 100644 drivers/usb/misc/usbio.c
 create mode 100644 include/linux/usb/usbio.h

-- 
2.51.0

[PATCH v4 1/3] usb: misc: Add Intel USBIO bridge driver

[Hans de Goede]

From: Israel Cepeda <israel.a.cepeda.lopez@intel.com>

Add a driver for the Intel USBIO USB IO-expander used by the MIPI cameras
on various new (Meteor Lake and later) Intel laptops.

This is an USB bridge driver which adds auxbus child devices for the GPIO,
I2C and SPI functions of the USBIO chip and which exports IO-functions for
the drivers for the auxbus child devices to communicate with the USBIO
device's firmware.

Co-developed-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Israel Cepeda <israel.a.cepeda.lopez@intel.com>
---
Changes in v2:
- Split usbio-bridge mutex into ctrl_mutex and bulk_mutex
- Drop SPI support since this is not used on devices in the field
- Rework disconnect handling to be more robust
- Several different revisions need special casing add a quirks mechanism
  for this
- Stop using stdint.h (uintX_t) types
- Use __le16, __le32 type + cpu_to_le16() and friends for on wire words
- Properly check auxiliary_device_add() return value
- Some small style fixes from Sakari's review
---
 MAINTAINERS               |   8 +
 drivers/usb/misc/Kconfig  |  14 +
 drivers/usb/misc/Makefile |   1 +
 drivers/usb/misc/usbio.c  | 749 ++++++++++++++++++++++++++++++++++++++
 include/linux/usb/usbio.h | 177 +++++++++
 5 files changed, 949 insertions(+)
 create mode 100644 drivers/usb/misc/usbio.c
 create mode 100644 include/linux/usb/usbio.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d91348a66738..3410699ad0b2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12694,6 +12694,14 @@ S:	Maintained
 F:	Documentation/admin-guide/pm/intel_uncore_frequency_scaling.rst
 F:	drivers/platform/x86/intel/uncore-frequency/
 
+INTEL USBIO USB I/O EXPANDER DRIVERS
+M:	Israel Cepeda <israel.a.cepeda.lopez@intel.com>
+M:	Hans de Goede <hansg@kernel.org>
+R:	Sakari Ailus <sakari.ailus@linux.intel.com>
+S:	Maintained
+F:	drivers/usb/misc/usbio.c
+F:	include/linux/usb/usbio.h
+
 INTEL VENDOR SPECIFIC EXTENDED CAPABILITIES DRIVER
 M:	David E. Box <david.e.box@linux.intel.com>
 S:	Supported
diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 6497c4e81e95..bfe08e15d051 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -178,6 +178,20 @@ config USB_LJCA
 	  This driver can also be built as a module. If so, the module
 	  will be called usb-ljca.
 
+config USB_USBIO
+	tristate "Intel USBIO Bridge support"
+	depends on USB && ACPI
+	select AUXILIARY_BUS
+	help
+	  This adds support for Intel USBIO drivers.
+	  This enables the USBIO bridge driver module in charge to talk
+	  to the USB device. Additional drivers such as GPIO_USBIO and
+	  I2C_USBIO must be enabled in order to use the device's full
+	  functionality.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called usbio.
+
 source "drivers/usb/misc/sisusbvga/Kconfig"
 
 config USB_LD
diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
index 0cd5bc8f52fe..494ab0377f35 100644
--- a/drivers/usb/misc/Makefile
+++ b/drivers/usb/misc/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_USB_EMI62)			+= emi62.o
 obj-$(CONFIG_USB_EZUSB_FX2)		+= ezusb.o
 obj-$(CONFIG_APPLE_MFI_FASTCHARGE)	+= apple-mfi-fastcharge.o
 obj-$(CONFIG_USB_LJCA)			+= usb-ljca.o
+obj-$(CONFIG_USB_USBIO)			+= usbio.o
 obj-$(CONFIG_USB_IDMOUSE)		+= idmouse.o
 obj-$(CONFIG_USB_IOWARRIOR)		+= iowarrior.o
 obj-$(CONFIG_USB_ISIGHTFW)		+= isight_firmware.o
diff --git a/drivers/usb/misc/usbio.c b/drivers/usb/misc/usbio.c
new file mode 100644
index 000000000000..37644dddf157
--- /dev/null
+++ b/drivers/usb/misc/usbio.c
@@ -0,0 +1,749 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel USBIO Bridge driver
+ *
+ * Copyright (c) 2025 Intel Corporation.
+ * Copyright (c) 2025 Red Hat, Inc.
+ */
+
+#include <linux/acpi.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/byteorder/generic.h>
+#include <linux/cleanup.h>
+#include <linux/completion.h>
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/lockdep.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/usb.h>
+#include <linux/usb/usbio.h>
+
+/*************************************
+ * USBIO Bridge Protocol Definitions *
+ *************************************/
+
+/* USBIO Control Commands */
+#define USBIO_CTRLCMD_PROTVER	0
+#define USBIO_CTRLCMD_FWVER	1
+#define USBIO_CTRLCMD_HS	2
+#define USBIO_CTRLCMD_ENUMGPIO	16
+#define USBIO_CTRLCMD_ENUMI2C	17
+
+/* USBIO Packet Flags */
+#define USBIO_PKTFLAG_ACK	BIT(0)
+#define USBIO_PKTFLAG_RSP	BIT(1)
+#define USBIO_PKTFLAG_CMP	BIT(2)
+#define USBIO_PKTFLAG_ERR	BIT(3)
+
+#define USBIO_PKTFLAGS_REQRESP	(USBIO_PKTFLAG_CMP | USBIO_PKTFLAG_ACK)
+
+#define USBIO_CTRLXFER_TIMEOUT 0
+#define USBIO_BULKXFER_TIMEOUT 100
+
+struct usbio_protver {
+	u8 ver;
+} __packed;
+
+struct usbio_fwver {
+	u8 major;
+	u8 minor;
+	__le16 patch;
+	__le16 build;
+} __packed;
+
+/***********************************
+ * USBIO Bridge Device Definitions *
+ ***********************************/
+
+/**
+ * struct usbio_device - the usb device exposing IOs
+ *
+ * @dev: the device in the usb interface
+ * @udev: the detected usb device
+ * @intf: the usb interface
+ * @quirks: quirks
+ * @ctrl_mutex: protects ctrl_buf
+ * @ctrl_pipe: the control transfer pipe
+ * @ctrlbuf_len: the size of the control transfer pipe
+ * @ctrlbuf: the buffer used for control transfers
+ * @bulk_mutex: protects tx_buf, rx_buf and split bulk-transfers getting interrupted
+ * @tx_pipe: the bulk out pipe
+ * @txbuf_len: the size of the bulk out pipe
+ * @txbuf: the buffer used for bulk out transfers
+ * @rx_pipe: the bulk in pipe
+ * @rxbuf_len: the size of the bulk in pipe
+ * @rxdat_len: the data length at rx buffer
+ * @rxbuf: the buffer used for bulk in transfers
+ * @urb: the urb to read bulk pipe
+ * @done: completion object as request is done
+ * @cli_list: device's client list
+ * @nr_gpio_banks: Number of GPIO banks
+ * @gpios: GPIO bank descriptors
+ * @nr_gpio_banks: Number of I2C busses
+ * @gpios: I2C bank descriptors
+ */
+struct usbio_device {
+	struct device *dev;
+	struct usb_device *udev;
+	struct usb_interface *intf;
+	unsigned long quirks;
+
+	struct mutex ctrl_mutex;
+	unsigned int ctrl_pipe;
+	u16 ctrlbuf_len;
+	void *ctrlbuf;
+
+	struct mutex bulk_mutex;
+	unsigned int tx_pipe;
+	u16 txbuf_len;
+	void *txbuf;
+
+	unsigned int rx_pipe;
+	u16 rxbuf_len;
+	u16 rxdat_len;
+	void *rxbuf;
+	struct urb *urb;
+
+	struct completion done;
+
+	struct list_head cli_list;
+
+	unsigned int nr_gpio_banks;
+	struct usbio_gpio_bank_desc gpios[USBIO_MAX_GPIOBANKS];
+
+	unsigned int nr_i2c_buses;
+	struct usbio_i2c_bus_desc i2cs[USBIO_MAX_I2CBUSES];
+};
+
+/**
+ * struct usbio_client - represents a usbio client
+ *
+ * @auxdev: auxiliary device object
+ * @mutex: protects @bridge
+ * @bridge: usbio bridge who service the client
+ * @link: usbio bridge clients list member
+ */
+struct usbio_client {
+	struct auxiliary_device auxdev;
+	struct mutex mutex;
+	struct usbio_device *bridge;
+	struct list_head link;
+};
+
+#define adev_to_client(adev) container_of_const(adev, struct usbio_client, auxdev)
+
+static int usbio_ctrl_msg(struct usbio_device *usbio, u8 type, u8 cmd,
+			  const void *obuf, u16 obuf_len, void *ibuf, u16 ibuf_len)
+{
+	u8 request = USB_TYPE_VENDOR | USB_RECIP_DEVICE;
+	struct usbio_ctrl_packet *cpkt;
+	unsigned int pipe;
+	u16 cpkt_len;
+	int ret;
+
+	lockdep_assert_held(&usbio->ctrl_mutex);
+
+	if ((obuf_len > (usbio->ctrlbuf_len - sizeof(*cpkt))) ||
+	    (ibuf_len > (usbio->ctrlbuf_len - sizeof(*cpkt))))
+		return -EMSGSIZE;
+
+	/* Prepare Control Packet Header */
+	cpkt = usbio->ctrlbuf;
+	cpkt->header.type = type;
+	cpkt->header.cmd = cmd;
+	if (type == USBIO_PKTTYPE_CTRL || ibuf_len)
+		cpkt->header.flags = USBIO_PKTFLAGS_REQRESP;
+	else
+		cpkt->header.flags = USBIO_PKTFLAG_CMP;
+	cpkt->len = obuf_len;
+
+	/* Copy the data */
+	memcpy(cpkt->data, obuf, obuf_len);
+
+	pipe = usb_sndctrlpipe(usbio->udev, usbio->ctrl_pipe);
+	cpkt_len = sizeof(*cpkt) + obuf_len;
+	ret = usb_control_msg(usbio->udev, pipe, 0, request | USB_DIR_OUT, 0, 0,
+			      cpkt, cpkt_len, USBIO_CTRLXFER_TIMEOUT);
+	dev_dbg(usbio->dev, "control out %d hdr %*phN data %*phN\n", ret,
+		(int)sizeof(*cpkt), cpkt, (int)cpkt->len, cpkt->data);
+
+	if (ret != cpkt_len) {
+		dev_err(usbio->dev, "USB control out failed: %d\n", ret);
+		return (ret < 0) ? ret : -EPROTO;
+	}
+
+	if (!(cpkt->header.flags & USBIO_PKTFLAG_ACK))
+		return 0;
+
+	pipe = usb_rcvctrlpipe(usbio->udev, usbio->ctrl_pipe);
+	cpkt_len = sizeof(*cpkt) + ibuf_len;
+	ret = usb_control_msg(usbio->udev, pipe, 0, request | USB_DIR_IN, 0, 0,
+			      cpkt, cpkt_len, USBIO_CTRLXFER_TIMEOUT);
+	dev_dbg(usbio->dev, "control in %d hdr %*phN data %*phN\n", ret,
+		(int)sizeof(*cpkt), cpkt, (int)cpkt->len, cpkt->data);
+
+	if (ret < sizeof(*cpkt)) {
+		dev_err(usbio->dev, "USB control in failed: %d\n", ret);
+		return (ret < 0) ? ret : -EPROTO;
+	}
+
+	if (cpkt->header.type != type || cpkt->header.cmd != cmd ||
+	    !(cpkt->header.flags & USBIO_PKTFLAG_RSP)) {
+		dev_err(usbio->dev, "Unexpected reply type: %u, cmd: %u, flags: %u\n",
+			cpkt->header.type, cpkt->header.cmd, cpkt->header.flags);
+		return -EPROTO;
+	}
+
+	if (cpkt->header.flags & USBIO_PKTFLAG_ERR)
+		return -EREMOTEIO;
+
+	if (ibuf_len < cpkt->len)
+		return -ENOSPC;
+
+	memcpy(ibuf, cpkt->data, cpkt->len);
+
+	return cpkt->len;
+}
+
+int usbio_control_msg(struct auxiliary_device *adev, u8 type, u8 cmd,
+		      const void *obuf, u16 obuf_len, void *ibuf, u16 ibuf_len)
+{
+	struct usbio_client *client = adev_to_client(adev);
+	struct usbio_device *usbio;
+	int ret;
+
+	guard(mutex)(&client->mutex);
+
+	usbio = client->bridge;
+	if (!usbio)
+		return -ENODEV; /* Disconnected */
+
+	ret = usb_autopm_get_interface(usbio->intf);
+	if (ret)
+		return ret;
+
+	mutex_lock(&usbio->ctrl_mutex);
+
+	ret = usbio_ctrl_msg(client->bridge, type, cmd, obuf, obuf_len, ibuf, ibuf_len);
+
+	mutex_unlock(&usbio->ctrl_mutex);
+	usb_autopm_put_interface(usbio->intf);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(usbio_control_msg, "USBIO");
+
+static void usbio_bulk_recv(struct urb *urb)
+{
+	struct usbio_bulk_packet *bpkt = urb->transfer_buffer;
+	struct usbio_device *usbio = urb->context;
+
+	if (!urb->status) {
+		if (bpkt->header.flags & USBIO_PKTFLAG_RSP) {
+			usbio->rxdat_len = urb->actual_length;
+			complete(&usbio->done);
+		}
+	} else if (urb->status != -ENOENT) {
+		dev_err(usbio->dev, "Bulk in error %d\n", urb->status);
+	}
+
+	usb_submit_urb(usbio->urb, GFP_ATOMIC);
+}
+
+int usbio_bulk_msg(struct auxiliary_device *adev, u8 type, u8 cmd, bool last,
+		   const void *obuf, u16 obuf_len, void *ibuf, u16 ibuf_len)
+{
+	struct usbio_client *client = adev_to_client(adev);
+	struct usbio_device *usbio = client->bridge;
+	struct usbio_bulk_packet *bpkt;
+	int ret, act = 0;
+	u16 bpkt_len;
+
+	lockdep_assert_held(&client->mutex);
+	lockdep_assert_held(&usbio->bulk_mutex);
+
+	if ((obuf_len > (usbio->txbuf_len - sizeof(*bpkt))) ||
+	    (ibuf_len > (usbio->txbuf_len - sizeof(*bpkt))))
+		return -EMSGSIZE;
+
+	if (ibuf_len)
+		reinit_completion(&usbio->done);
+
+	/* If no data to send, skip to read */
+	if (!obuf_len)
+		goto read;
+
+	/* Prepare Bulk Packet Header */
+	bpkt = usbio->txbuf;
+	bpkt->header.type = type;
+	bpkt->header.cmd = cmd;
+	if (!last)
+		bpkt->header.flags = 0;
+	else if (ibuf_len)
+		bpkt->header.flags = USBIO_PKTFLAGS_REQRESP;
+	else
+		bpkt->header.flags = USBIO_PKTFLAG_CMP;
+	bpkt->len = cpu_to_le16(obuf_len);
+
+	/* Copy the data */
+	memcpy(bpkt->data, obuf, obuf_len);
+
+	bpkt_len = sizeof(*bpkt) + obuf_len;
+	ret = usb_bulk_msg(usbio->udev, usbio->tx_pipe, bpkt, bpkt_len, &act,
+			   USBIO_BULKXFER_TIMEOUT);
+	dev_dbg(usbio->dev, "bulk out %d hdr %*phN data %*phN\n", act,
+		(int)sizeof(*bpkt), bpkt, obuf_len, bpkt->data);
+
+	if (ret || act != bpkt_len) {
+		dev_err(usbio->dev, "Bulk out failed: %d\n", ret);
+		return ret ?: -EPROTO;
+	}
+
+	if (!(bpkt->header.flags & USBIO_PKTFLAG_ACK))
+		return obuf_len;
+
+read:
+	ret = wait_for_completion_timeout(&usbio->done, USBIO_BULKXFER_TIMEOUT);
+	if (ret <= 0) {
+		dev_err(usbio->dev, "Bulk in wait failed: %d\n", ret);
+		return ret ?: -ETIMEDOUT;
+	}
+
+	act = usbio->rxdat_len;
+	bpkt = usbio->rxbuf;
+	bpkt_len = le16_to_cpu(bpkt->len);
+	dev_dbg(usbio->dev, "bulk in %d hdr %*phN data %*phN\n", act,
+		(int)sizeof(*bpkt), bpkt, bpkt_len, bpkt->data);
+
+	/*
+	 * Unsupported bulk commands get only an usbio_packet_header with
+	 * the error flag set as reply. Return -EPIPE for this case.
+	 */
+	if (act == sizeof(struct usbio_packet_header) &&
+	    (bpkt->header.flags & USBIO_PKTFLAG_ERR))
+		return -EPIPE;
+
+	if (act < sizeof(*bpkt)) {
+		dev_err(usbio->dev, "Bulk in short read: %d\n", act);
+		return -EPROTO;
+	}
+
+	if (bpkt->header.type != type || bpkt->header.cmd != cmd ||
+	    !(bpkt->header.flags & USBIO_PKTFLAG_RSP)) {
+		dev_err(usbio->dev,
+			"Unexpected bulk in type 0x%02x cmd 0x%02x flags 0x%02x\n",
+			bpkt->header.type, bpkt->header.cmd, bpkt->header.flags);
+		return -EPROTO;
+	}
+
+	if (bpkt->header.flags & USBIO_PKTFLAG_ERR)
+		return -EREMOTEIO;
+
+	if (ibuf_len < bpkt_len)
+		return -ENOSPC;
+
+	memcpy(ibuf, bpkt->data, bpkt_len);
+
+	return bpkt_len;
+}
+EXPORT_SYMBOL_NS_GPL(usbio_bulk_msg, "USBIO");
+
+int usbio_acquire(struct auxiliary_device *adev)
+{
+	struct usbio_client *client = adev_to_client(adev);
+	struct usbio_device *usbio;
+	int ret;
+
+	mutex_lock(&client->mutex);
+
+	usbio = client->bridge;
+	if (!usbio) {
+		ret = -ENODEV; /* Disconnected */
+		goto err_unlock;
+	}
+
+	ret = usb_autopm_get_interface(usbio->intf);
+	if (ret)
+		goto err_unlock;
+
+	mutex_lock(&usbio->bulk_mutex);
+
+	/* Leave client locked until release to avoid abba deadlock issues */
+	return 0;
+
+err_unlock:
+	mutex_unlock(&client->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(usbio_acquire, "USBIO");
+
+void usbio_release(struct auxiliary_device *adev)
+{
+	struct usbio_client *client = adev_to_client(adev);
+	struct usbio_device *usbio = client->bridge;
+
+	lockdep_assert_held(&client->mutex);
+
+	mutex_unlock(&usbio->bulk_mutex);
+	usb_autopm_put_interface(usbio->intf);
+	mutex_unlock(&client->mutex);
+}
+EXPORT_SYMBOL_NS_GPL(usbio_release, "USBIO");
+
+void usbio_get_txrxbuf_len(struct auxiliary_device *adev, u16 *txbuf_len, u16 *rxbuf_len)
+{
+	struct usbio_client *client = adev_to_client(adev);
+	struct usbio_device *usbio;
+
+	guard(mutex)(&client->mutex);
+
+	usbio = client->bridge;
+	if (!usbio)
+		return; /* Disconnected */
+
+	*txbuf_len = usbio->txbuf_len;
+	*rxbuf_len = usbio->rxbuf_len;
+}
+EXPORT_SYMBOL_NS_GPL(usbio_get_txrxbuf_len, "USBIO");
+
+unsigned long usbio_get_quirks(struct auxiliary_device *adev)
+{
+	struct usbio_client *client = adev_to_client(adev);
+	struct usbio_device *usbio;
+
+	guard(mutex)(&client->mutex);
+
+	usbio = client->bridge;
+	if (!usbio)
+		return 0; /* Disconnected */
+
+	return usbio->quirks;
+}
+EXPORT_SYMBOL_NS_GPL(usbio_get_quirks, "USBIO");
+
+static void usbio_auxdev_release(struct device *dev)
+{
+	struct auxiliary_device *adev = to_auxiliary_dev(dev);
+	struct usbio_client *client = adev_to_client(adev);
+
+	mutex_destroy(&client->mutex);
+	kfree(client);
+}
+
+static int usbio_add_client(struct usbio_device *usbio, char *name, u8 id, void *data)
+{
+	struct usbio_client *client;
+	struct auxiliary_device *adev;
+	int ret;
+
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return -ENOMEM;
+
+	mutex_init(&client->mutex);
+	client->bridge = usbio;
+	adev = &client->auxdev;
+	adev->name = name;
+	adev->id = id;
+
+	adev->dev.parent = usbio->dev;
+	adev->dev.platform_data = data;
+	adev->dev.release = usbio_auxdev_release;
+
+	ret = auxiliary_device_init(adev);
+	if (ret) {
+		usbio_auxdev_release(&adev->dev);
+		return ret;
+	}
+
+	ret = auxiliary_device_add(adev);
+	if (ret) {
+		auxiliary_device_uninit(adev);
+		return ret;
+	}
+
+	list_add_tail(&client->link, &usbio->cli_list);
+
+	return 0;
+}
+
+static int usbio_enum_gpios(struct usbio_device *usbio)
+{
+	struct usbio_gpio_bank_desc *gpio = usbio->gpios;
+
+	dev_dbg(usbio->dev, "GPIO Banks: %d\n", usbio->nr_gpio_banks);
+
+	for (unsigned int i = 0; i < usbio->nr_gpio_banks; i++)
+		dev_dbg(usbio->dev, "\tBank%d[%d] map: %#08x\n",
+			gpio[i].id, gpio[i].pins, gpio[i].bmap);
+
+	usbio_add_client(usbio, USBIO_GPIO_CLIENT, 0, gpio);
+
+	return 0;
+}
+
+static int usbio_enum_i2cs(struct usbio_device *usbio)
+{
+	struct usbio_i2c_bus_desc *i2c = usbio->i2cs;
+
+	dev_dbg(usbio->dev, "I2C Busses: %d\n", usbio->nr_i2c_buses);
+
+	for (unsigned int i = 0; i < usbio->nr_i2c_buses; i++) {
+		dev_dbg(usbio->dev, "\tBus%d caps: %#02x\n", i2c[i].id, i2c[i].caps);
+		usbio_add_client(usbio, USBIO_I2C_CLIENT, i, &i2c[i]);
+	}
+
+	return 0;
+}
+
+static int usbio_suspend(struct usb_interface *intf, pm_message_t msg)
+{
+	struct usbio_device *usbio = usb_get_intfdata(intf);
+
+	usb_kill_urb(usbio->urb);
+
+	return 0;
+}
+
+static int usbio_resume(struct usb_interface *intf)
+{
+	struct usbio_device *usbio = usb_get_intfdata(intf);
+
+	return usb_submit_urb(usbio->urb, GFP_KERNEL);
+}
+
+static void usbio_disconnect(struct usb_interface *intf)
+{
+	struct usbio_device *usbio = usb_get_intfdata(intf);
+	struct usbio_client *client;
+
+	/* Wakeup any clients waiting for a reply */
+	usbio->rxdat_len = 0;
+	complete(&usbio->done);
+
+	/* Let clients know the bridge is gone */
+	list_for_each_entry(client, &usbio->cli_list, link) {
+		mutex_lock(&client->mutex);
+		client->bridge = NULL;
+		mutex_unlock(&client->mutex);
+	}
+
+	/* From here on clients will no longer touch struct usbio_device */
+	usb_kill_urb(usbio->urb);
+	usb_free_urb(usbio->urb);
+
+	list_for_each_entry_reverse(client, &usbio->cli_list, link) {
+		auxiliary_device_delete(&client->auxdev);
+		auxiliary_device_uninit(&client->auxdev);
+	}
+}
+
+static int usbio_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct usb_endpoint_descriptor *ep_in, *ep_out;
+	struct device *dev = &intf->dev;
+	struct usbio_protver protver;
+	struct usbio_device *usbio;
+	struct usbio_fwver fwver;
+	int ret;
+
+	usbio = devm_kzalloc(dev, sizeof(*usbio), GFP_KERNEL);
+	if (!usbio)
+		return -ENOMEM;
+
+	ret = devm_mutex_init(dev, &usbio->ctrl_mutex);
+	if (ret)
+		return ret;
+
+	ret = devm_mutex_init(dev, &usbio->bulk_mutex);
+	if (ret)
+		return ret;
+
+	usbio->dev = dev;
+	usbio->udev = udev;
+	usbio->intf = intf;
+	usbio->quirks = id ? id->driver_info : 0;
+	init_completion(&usbio->done);
+	INIT_LIST_HEAD(&usbio->cli_list);
+	usb_set_intfdata(intf, usbio);
+
+	usbio->ctrl_pipe = usb_endpoint_num(&udev->ep0.desc);
+	usbio->ctrlbuf_len = usb_maxpacket(udev, usbio->ctrl_pipe);
+	usbio->ctrlbuf = devm_kzalloc(dev, usbio->ctrlbuf_len, GFP_KERNEL);
+	if (!usbio->ctrlbuf)
+		return -ENOMEM;
+
+	/* Find the first bulk-in and bulk-out endpoints */
+	ret = usb_find_common_endpoints(intf->cur_altsetting, &ep_in, &ep_out,
+					NULL, NULL);
+	if (ret) {
+		dev_err(dev, "Cannot find bulk endpoints: %d\n", ret);
+		return ret;
+	}
+
+	usbio->tx_pipe = usb_sndbulkpipe(udev, usb_endpoint_num(ep_out));
+
+	if (usbio->quirks & USBIO_QUIRK_BULK_MAXP_63)
+		usbio->txbuf_len = 63;
+	else
+		usbio->txbuf_len = usb_endpoint_maxp(ep_out);
+
+	usbio->txbuf = devm_kzalloc(dev, usbio->txbuf_len, GFP_KERNEL);
+	if (!usbio->txbuf)
+		return -ENOMEM;
+
+	usbio->rx_pipe = usb_rcvbulkpipe(udev, usb_endpoint_num(ep_in));
+
+	if (usbio->quirks & USBIO_QUIRK_BULK_MAXP_63)
+		usbio->rxbuf_len = 63;
+	else
+		usbio->rxbuf_len = usb_endpoint_maxp(ep_in);
+
+	usbio->rxbuf = devm_kzalloc(dev, usbio->rxbuf_len, GFP_KERNEL);
+	if (!usbio->rxbuf)
+		return -ENOMEM;
+
+	usbio->urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!usbio->urb)
+		return -ENOMEM;
+
+	usb_fill_bulk_urb(usbio->urb, udev, usbio->rx_pipe, usbio->rxbuf,
+			  usbio->rxbuf_len, usbio_bulk_recv, usbio);
+	ret = usb_submit_urb(usbio->urb, GFP_KERNEL);
+	if (ret)
+		return dev_err_probe(dev, ret, "Submitting usb urb\n");
+
+	mutex_lock(&usbio->ctrl_mutex);
+
+	ret = usbio_ctrl_msg(usbio, USBIO_PKTTYPE_CTRL, USBIO_CTRLCMD_HS, NULL, 0, NULL, 0);
+	if (ret < 0)
+		goto err_unlock;
+
+	ret = usbio_ctrl_msg(usbio, USBIO_PKTTYPE_CTRL, USBIO_CTRLCMD_PROTVER, NULL, 0,
+			     &protver, sizeof(protver));
+	if (ret < 0)
+		goto err_unlock;
+
+	ret = usbio_ctrl_msg(usbio, USBIO_PKTTYPE_CTRL, USBIO_CTRLCMD_FWVER, NULL, 0,
+			     &fwver, sizeof(fwver));
+	if (ret < 0)
+		goto err_unlock;
+
+	ret = usbio_ctrl_msg(usbio, USBIO_PKTTYPE_CTRL, USBIO_CTRLCMD_ENUMGPIO, NULL, 0,
+			     usbio->gpios, sizeof(usbio->gpios));
+	if (ret < 0 || ret % sizeof(struct usbio_gpio_bank_desc)) {
+		ret = (ret < 0) ? ret : -EPROTO;
+		goto err_unlock;
+	}
+	usbio->nr_gpio_banks = ret / sizeof(struct usbio_gpio_bank_desc);
+
+	ret = usbio_ctrl_msg(usbio, USBIO_PKTTYPE_CTRL, USBIO_CTRLCMD_ENUMI2C, NULL, 0,
+			     usbio->i2cs, sizeof(usbio->i2cs));
+	if (ret < 0 || ret % sizeof(struct usbio_i2c_bus_desc)) {
+		ret = (ret < 0) ? ret : -EPROTO;
+		goto err_unlock;
+	}
+	usbio->nr_i2c_buses = ret / sizeof(struct usbio_i2c_bus_desc);
+
+	mutex_unlock(&usbio->ctrl_mutex);
+
+	dev_dbg(dev, "ProtVer(BCD): %02x FwVer: %d.%d.%d.%d\n",
+		protver.ver, fwver.major, fwver.minor,
+		le16_to_cpu(fwver.patch), le16_to_cpu(fwver.build));
+
+	usbio_enum_gpios(usbio);
+	usbio_enum_i2cs(usbio);
+
+	return 0;
+
+err_unlock:
+	mutex_unlock(&usbio->ctrl_mutex);
+	usb_kill_urb(usbio->urb);
+	usb_free_urb(usbio->urb);
+
+	return ret;
+}
+
+static const struct usb_device_id usbio_table[] = {
+	{ USB_DEVICE(0x2ac1, 0x20c1),	/* Lattice NX40 */
+	  .driver_info = USBIO_QUIRK_I2C_MAX_RW_LEN_52 },
+	{ USB_DEVICE(0x2ac1, 0x20c9),	/* Lattice NX33 */
+	  .driver_info = USBIO_QUIRK_I2C_NO_INIT_ACK | USBIO_QUIRK_I2C_MAX_RW_LEN_52 |
+			 USBIO_QUIRK_I2C_ALLOW_400KHZ },
+	{ USB_DEVICE(0x2ac1, 0x20cb) },	/* Lattice NX33U */
+	{ USB_DEVICE(0x06cb, 0x0701),	/* Synaptics Sabre */
+	  .driver_info = USBIO_QUIRK_BULK_MAXP_63 | USBIO_QUIRK_I2C_USE_CHUNK_LEN },
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, usbio_table);
+
+static struct usb_driver usbio_driver = {
+	.name = "usbio-bridge",
+	.probe = usbio_probe,
+	.disconnect = usbio_disconnect,
+	.suspend = usbio_suspend,
+	.resume = usbio_resume,
+	.id_table = usbio_table,
+	.supports_autosuspend = 1,
+};
+module_usb_driver(usbio_driver);
+
+struct usbio_match_ids_walk_data {
+	struct acpi_device *adev;
+	const struct acpi_device_id *hids;
+	unsigned int id;
+};
+
+static int usbio_match_device_ids(struct acpi_device *adev, void *data)
+{
+	struct usbio_match_ids_walk_data *wd = data;
+	unsigned int id = 0;
+	char *uid;
+
+	if (acpi_match_device_ids(adev, wd->hids))
+		return 0;
+
+	uid = acpi_device_uid(adev);
+	if (uid) {
+		for (int i = 0; i < strlen(uid); i++) {
+			if (!kstrtouint(&uid[i], 10, &id))
+				break;
+		}
+	}
+
+	if (!uid || wd->id == id) {
+		wd->adev = adev;
+		return 1;
+	}
+
+	return 0;
+}
+
+void usbio_acpi_bind(struct auxiliary_device *adev, const struct acpi_device_id *hids)
+{
+	struct device *dev = &adev->dev;
+	struct acpi_device *parent;
+	struct usbio_match_ids_walk_data wd = {
+		.adev = NULL,
+		.hids = hids,
+		.id = adev->id,
+	};
+
+	parent = ACPI_COMPANION(dev->parent);
+	if (!parent)
+		return;
+
+	acpi_dev_for_each_child(parent, usbio_match_device_ids, &wd);
+	if (wd.adev)
+		ACPI_COMPANION_SET(dev, wd.adev);
+}
+EXPORT_SYMBOL_NS_GPL(usbio_acpi_bind, "USBIO");
+
+MODULE_DESCRIPTION("Intel USBIO Bridge driver");
+MODULE_AUTHOR("Israel Cepeda <israel.a.cepeda.lopez@intel.com>");
+MODULE_AUTHOR("Hans de Goede <hansg@kernel.org>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/usb/usbio.h b/include/linux/usb/usbio.h
new file mode 100644
index 000000000000..6c4e7c246d58
--- /dev/null
+++ b/include/linux/usb/usbio.h
@@ -0,0 +1,177 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2025 Intel Corporation.
+ *
+ */
+
+#ifndef _LINUX_USBIO_H_
+#define _LINUX_USBIO_H_
+
+#include <linux/auxiliary_bus.h>
+#include <linux/byteorder/generic.h>
+#include <linux/list.h>
+#include <linux/types.h>
+
+/***********************
+ * USBIO Clients Names *
+ ***********************/
+#define USBIO_GPIO_CLIENT		"usbio-gpio"
+#define USBIO_I2C_CLIENT		"usbio-i2c"
+
+/****************
+ * USBIO quirks *
+ ****************/
+#define USBIO_QUIRK_BULK_MAXP_63	BIT(0)  /* Force bulk endpoint maxp to 63 */
+#define USBIO_QUIRK_I2C_NO_INIT_ACK	BIT(8)  /* Do not ask for ack on I2C init */
+#define USBIO_QUIRK_I2C_MAX_RW_LEN_52	BIT(9)  /* Set i2c-adapter max r/w len to 52 */
+#define USBIO_QUIRK_I2C_USE_CHUNK_LEN	BIT(10) /* Send chunk-len for split xfers */
+#define USBIO_QUIRK_I2C_ALLOW_400KHZ	BIT(11) /* Override desc, allowing 400 KHz */
+
+/**************************
+ * USBIO Type Definitions *
+ **************************/
+
+/* USBIO Packet Type */
+#define USBIO_PKTTYPE_CTRL		1
+#define USBIO_PKTTYPE_DBG		2
+#define USBIO_PKTTYPE_GPIO		3
+#define USBIO_PKTTYPE_I2C		4
+
+/* USBIO Packet Header */
+struct usbio_packet_header {
+	u8 type;
+	u8 cmd;
+	u8 flags;
+} __packed;
+
+/* USBIO Control Transfer Packet */
+struct usbio_ctrl_packet {
+	struct usbio_packet_header header;
+	u8 len;
+	u8 data[] __counted_by(len);
+} __packed;
+
+/* USBIO Bulk Transfer Packet */
+struct usbio_bulk_packet {
+	struct usbio_packet_header header;
+	__le16 len;
+	u8 data[] __counted_by(len);
+} __packed;
+
+/* USBIO GPIO commands */
+enum usbio_gpio_cmd {
+	USBIO_GPIOCMD_DEINIT,
+	USBIO_GPIOCMD_INIT,
+	USBIO_GPIOCMD_READ,
+	USBIO_GPIOCMD_WRITE,
+	USBIO_GPIOCMD_END
+};
+
+/* USBIO GPIO config */
+enum usbio_gpio_pincfg {
+	USBIO_GPIO_PINCFG_DEFAULT,
+	USBIO_GPIO_PINCFG_PULLUP,
+	USBIO_GPIO_PINCFG_PULLDOWN,
+	USBIO_GPIO_PINCFG_PUSHPULL
+};
+
+#define USBIO_GPIO_PINCFG_SHIFT		2
+#define USBIO_GPIO_PINCFG_MASK		(0x3 << USBIO_GPIO_PINCFG_SHIFT)
+#define USBIO_GPIO_SET_PINCFG(pincfg) \
+	(((pincfg) << USBIO_GPIO_PINCFG_SHIFT) & USBIO_GPIO_PINCFG_MASK)
+
+enum usbio_gpio_pinmode {
+	USBIO_GPIO_PINMOD_INVAL,
+	USBIO_GPIO_PINMOD_INPUT,
+	USBIO_GPIO_PINMOD_OUTPUT,
+	USBIO_GPIO_PINMOD_MAXVAL
+};
+
+#define USBIO_GPIO_PINMOD_MASK		0x3
+#define USBIO_GPIO_SET_PINMOD(pin)	(pin & USBIO_GPIO_PINMOD_MASK)
+
+/*************************
+ * USBIO GPIO Controller *
+ *************************/
+
+#define USBIO_MAX_GPIOBANKS		5
+#define USBIO_GPIOSPERBANK		32
+
+struct usbio_gpio_bank_desc {
+	u8 id;
+	u8 pins;
+	__le32 bmap;
+} __packed;
+
+struct usbio_gpio_init {
+	u8 bankid;
+	u8 config;
+	u8 pincount;
+	u8 pin;
+} __packed;
+
+struct usbio_gpio_rw {
+	u8 bankid;
+	u8 pincount;
+	u8 pin;
+	__le32 value;
+} __packed;
+
+/* USBIO I2C commands */
+enum usbio_i2c_cmd {
+	USBIO_I2CCMD_UNINIT,
+	USBIO_I2CCMD_INIT,
+	USBIO_I2CCMD_READ,
+	USBIO_I2CCMD_WRITE,
+	USBIO_I2CCMD_END
+};
+
+/************************
+ * USBIO I2C Controller *
+ ************************/
+
+#define USBIO_MAX_I2CBUSES 5
+
+#define USBIO_I2C_BUS_ADDR_CAP_10B	BIT(3) /* 10bit address support */
+#define USBIO_I2C_BUS_MODE_CAP_MASK	0x3
+#define USBIO_I2C_BUS_MODE_CAP_SM	0 /* Standard Mode */
+#define USBIO_I2C_BUS_MODE_CAP_FM	1 /* Fast Mode */
+#define USBIO_I2C_BUS_MODE_CAP_FMP	2 /* Fast Mode+ */
+#define USBIO_I2C_BUS_MODE_CAP_HSM	3 /* High-Speed Mode */
+
+struct usbio_i2c_bus_desc {
+	u8 id;
+	u8 caps;
+} __packed;
+
+struct usbio_i2c_uninit {
+	u8 busid;
+	__le16 config;
+} __packed;
+
+struct usbio_i2c_init {
+	u8 busid;
+	__le16 config;
+	__le32 speed;
+} __packed;
+
+struct usbio_i2c_rw {
+	u8 busid;
+	__le16 config;
+	__le16 size;
+	u8 data[] __counted_by(size);
+} __packed;
+
+int usbio_control_msg(struct auxiliary_device *adev, u8 type, u8 cmd,
+		      const void *obuf, u16 obuf_len, void *ibuf, u16 ibuf_len);
+
+int usbio_bulk_msg(struct auxiliary_device *adev, u8 type, u8 cmd, bool last,
+		   const void *obuf, u16 obuf_len, void *ibuf, u16 ibuf_len);
+
+int usbio_acquire(struct auxiliary_device *adev);
+void usbio_release(struct auxiliary_device *adev);
+void usbio_get_txrxbuf_len(struct auxiliary_device *adev, u16 *txbuf_len, u16 *rxbuf_len);
+unsigned long usbio_get_quirks(struct auxiliary_device *adev);
+void usbio_acpi_bind(struct auxiliary_device *adev, const struct acpi_device_id *hids);
+
+#endif
-- 
2.51.0

[PATCH v4 2/3] gpio: Add Intel USBIO GPIO driver

[Hans de Goede]

From: Israel Cepeda <israel.a.cepeda.lopez@intel.com>

Add a a driver for the GPIO auxbus child device of the Intel USBIO USB
IO-expander used by the MIPI cameras on various new (Meteor Lake and
later) Intel laptops.

Co-developed-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Israel Cepeda <israel.a.cepeda.lopez@intel.com>
---
Changes in v4:
- Drop include <linux/dev_printk.h>, unneeded auxiliary_set_drvdata()

Changes in v3:
- Drop (offset >= gc->ngpio) check and make usbio_gpio_get_bank_and_pin()
  return void
- Propagate usbio_gpio_set() ret val in usbio_gpio_direction_output()
- Use devm_gpiochip_add_data() and drop auxiliary_driver remove() callback

Changes in v2:
- Add a config_mutex protect usbio_gpio_update_config() calls, which
  read-modify-write banks[x].config, racing with each other
- Adjust usbio_gpio_get() to have an int return value and propagate the
  usbio_control_msg() return value
- Use __le16, __le32 type + cpu_to_le16() and friends for on wire words
- Some small style fixes from Sakari's review
---
 MAINTAINERS               |   1 +
 drivers/gpio/Kconfig      |  11 ++
 drivers/gpio/Makefile     |   1 +
 drivers/gpio/gpio-usbio.c | 247 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 260 insertions(+)
 create mode 100644 drivers/gpio/gpio-usbio.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 3410699ad0b2..53694bd91861 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12699,6 +12699,7 @@ M:	Israel Cepeda <israel.a.cepeda.lopez@intel.com>
 M:	Hans de Goede <hansg@kernel.org>
 R:	Sakari Ailus <sakari.ailus@linux.intel.com>
 S:	Maintained
+F:	drivers/gpio/gpio-usbio.c
 F:	drivers/usb/misc/usbio.c
 F:	include/linux/usb/usbio.h
 
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e43abb322fa6..5d3ca3dd2687 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1448,6 +1448,17 @@ config GPIO_LJCA
 	  This driver can also be built as a module. If so, the module
 	  will be called gpio-ljca.
 
+config GPIO_USBIO
+	tristate "Intel USBIO GPIO support"
+	depends on USB_USBIO
+	default USB_USBIO
+	help
+	  Select this option to enable GPIO driver for the INTEL
+	  USBIO driver stack.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called gpio_usbio.
+
 config GPIO_LP3943
 	tristate "TI/National Semiconductor LP3943 GPIO expander"
 	depends on MFD_LP3943
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 379f55e9ed1e..8c55e2d5de42 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -90,6 +90,7 @@ obj-$(CONFIG_GPIO_JANZ_TTL)		+= gpio-janz-ttl.o
 obj-$(CONFIG_GPIO_KEMPLD)		+= gpio-kempld.o
 obj-$(CONFIG_GPIO_LATCH)		+= gpio-latch.o
 obj-$(CONFIG_GPIO_LJCA) 		+= gpio-ljca.o
+obj-$(CONFIG_GPIO_USBIO) 		+= gpio-usbio.o
 obj-$(CONFIG_GPIO_LOGICVC)		+= gpio-logicvc.o
 obj-$(CONFIG_GPIO_LOONGSON1)		+= gpio-loongson1.o
 obj-$(CONFIG_GPIO_LOONGSON)		+= gpio-loongson.o
diff --git a/drivers/gpio/gpio-usbio.c b/drivers/gpio/gpio-usbio.c
new file mode 100644
index 000000000000..e13c120824e3
--- /dev/null
+++ b/drivers/gpio/gpio-usbio.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025 Intel Corporation.
+ * Copyright (c) 2025 Red Hat, Inc.
+ */
+
+#include <linux/acpi.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+#include <linux/usb/usbio.h>
+
+struct usbio_gpio_bank {
+	u8 config[USBIO_GPIOSPERBANK];
+	u32 bitmap;
+};
+
+struct usbio_gpio {
+	struct mutex config_mutex; /* Protects banks[x].config */
+	struct usbio_gpio_bank banks[USBIO_MAX_GPIOBANKS];
+	struct gpio_chip gc;
+	struct auxiliary_device *adev;
+};
+
+static const struct acpi_device_id usbio_gpio_acpi_hids[] = {
+	{ "INTC1007" }, /* MTL */
+	{ "INTC10B2" }, /* ARL */
+	{ "INTC10B5" }, /* LNL */
+	{ "INTC10E2" }, /* PTL */
+	{ }
+};
+
+static void usbio_gpio_get_bank_and_pin(struct gpio_chip *gc, unsigned int offset,
+					struct usbio_gpio_bank **bank_ret,
+					unsigned int *pin_ret)
+{
+	struct usbio_gpio *gpio = gpiochip_get_data(gc);
+	struct device *dev = &gpio->adev->dev;
+	struct usbio_gpio_bank *bank;
+	unsigned int pin;
+
+	bank = &gpio->banks[offset / USBIO_GPIOSPERBANK];
+	pin = offset % USBIO_GPIOSPERBANK;
+	if (~bank->bitmap & BIT(pin)) {
+		/* The FW bitmap sometimes is invalid, warn and continue */
+		dev_warn_once(dev, FW_BUG "GPIO %u is not in FW pins bitmap\n", offset);
+	}
+
+	*bank_ret = bank;
+	*pin_ret = pin;
+}
+
+static int usbio_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	struct usbio_gpio_bank *bank;
+	unsigned int pin;
+	u8 cfg;
+
+	usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin);
+
+	cfg = bank->config[pin] & USBIO_GPIO_PINMOD_MASK;
+
+	return (cfg == USBIO_GPIO_PINMOD_OUTPUT) ?
+		GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
+}
+
+static int usbio_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+	struct usbio_gpio *gpio = gpiochip_get_data(gc);
+	struct usbio_gpio_bank *bank;
+	struct usbio_gpio_rw gbuf;
+	unsigned int pin;
+	int ret;
+
+	usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin);
+
+	gbuf.bankid = offset / USBIO_GPIOSPERBANK;
+	gbuf.pincount  = 1;
+	gbuf.pin = pin;
+
+	ret = usbio_control_msg(gpio->adev, USBIO_PKTTYPE_GPIO, USBIO_GPIOCMD_READ,
+				&gbuf, sizeof(gbuf) - sizeof(gbuf.value),
+				&gbuf, sizeof(gbuf));
+	if (ret != sizeof(gbuf))
+		return (ret < 0) ? ret : -EPROTO;
+
+	return (le32_to_cpu(gbuf.value) >> pin) & 1;
+}
+
+static int usbio_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	struct usbio_gpio *gpio = gpiochip_get_data(gc);
+	struct usbio_gpio_bank *bank;
+	struct usbio_gpio_rw gbuf;
+	unsigned int pin;
+
+	usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin);
+
+	gbuf.bankid = offset / USBIO_GPIOSPERBANK;
+	gbuf.pincount  = 1;
+	gbuf.pin = pin;
+	gbuf.value = cpu_to_le32(value << pin);
+
+	return usbio_control_msg(gpio->adev, USBIO_PKTTYPE_GPIO, USBIO_GPIOCMD_WRITE,
+				 &gbuf, sizeof(gbuf), NULL, 0);
+}
+
+static int usbio_gpio_update_config(struct gpio_chip *gc, unsigned int offset,
+				    u8 mask, u8 value)
+{
+	struct usbio_gpio *gpio = gpiochip_get_data(gc);
+	struct usbio_gpio_bank *bank;
+	struct usbio_gpio_init gbuf;
+	unsigned int pin;
+
+	usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin);
+
+	guard(mutex)(&gpio->config_mutex);
+
+	bank->config[pin] &= ~mask;
+	bank->config[pin] |= value;
+
+	gbuf.bankid = offset / USBIO_GPIOSPERBANK;
+	gbuf.config = bank->config[pin];
+	gbuf.pincount  = 1;
+	gbuf.pin = pin;
+
+	return usbio_control_msg(gpio->adev, USBIO_PKTTYPE_GPIO, USBIO_GPIOCMD_INIT,
+				 &gbuf, sizeof(gbuf), NULL, 0);
+}
+
+static int usbio_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+	return usbio_gpio_update_config(gc, offset, USBIO_GPIO_PINMOD_MASK,
+					USBIO_GPIO_SET_PINMOD(USBIO_GPIO_PINMOD_INPUT));
+}
+
+static int usbio_gpio_direction_output(struct gpio_chip *gc,
+		unsigned int offset, int value)
+{
+	int ret;
+
+	ret = usbio_gpio_update_config(gc, offset, USBIO_GPIO_PINMOD_MASK,
+				       USBIO_GPIO_SET_PINMOD(USBIO_GPIO_PINMOD_OUTPUT));
+	if (ret)
+		return ret;
+
+	return usbio_gpio_set(gc, offset, value);
+}
+
+static int usbio_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
+		unsigned long config)
+{
+	u8 value;
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT:
+		value = USBIO_GPIO_SET_PINCFG(USBIO_GPIO_PINCFG_DEFAULT);
+		break;
+	case PIN_CONFIG_BIAS_PULL_UP:
+		value = USBIO_GPIO_SET_PINCFG(USBIO_GPIO_PINCFG_PULLUP);
+		break;
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+		value = USBIO_GPIO_SET_PINCFG(USBIO_GPIO_PINCFG_PULLDOWN);
+		break;
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		value = USBIO_GPIO_SET_PINCFG(USBIO_GPIO_PINCFG_PUSHPULL);
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return usbio_gpio_update_config(gc, offset, USBIO_GPIO_PINCFG_MASK, value);
+}
+
+static int usbio_gpio_probe(struct auxiliary_device *adev,
+		const struct auxiliary_device_id *adev_id)
+{
+	struct usbio_gpio_bank_desc *bank_desc;
+	struct device *dev = &adev->dev;
+	struct usbio_gpio *gpio;
+	int bank, ret;
+
+	bank_desc = dev_get_platdata(dev);
+	if (!bank_desc)
+		return -EINVAL;
+
+	gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
+	if (!gpio)
+		return -ENOMEM;
+
+	ret = devm_mutex_init(dev, &gpio->config_mutex);
+	if (ret)
+		return ret;
+
+	gpio->adev = adev;
+
+	usbio_acpi_bind(gpio->adev, usbio_gpio_acpi_hids);
+
+	for (bank = 0; bank < USBIO_MAX_GPIOBANKS && bank_desc[bank].bmap; bank++)
+		gpio->banks[bank].bitmap = le32_to_cpu(bank_desc[bank].bmap);
+
+	gpio->gc.label = ACPI_COMPANION(dev) ?
+					acpi_dev_name(ACPI_COMPANION(dev)) : dev_name(dev);
+	gpio->gc.parent = dev;
+	gpio->gc.owner = THIS_MODULE;
+	gpio->gc.get_direction = usbio_gpio_get_direction;
+	gpio->gc.direction_input = usbio_gpio_direction_input;
+	gpio->gc.direction_output = usbio_gpio_direction_output;
+	gpio->gc.get = usbio_gpio_get;
+	gpio->gc.set = usbio_gpio_set;
+	gpio->gc.set_config = usbio_gpio_set_config;
+	gpio->gc.base = -1;
+	gpio->gc.ngpio = bank * USBIO_GPIOSPERBANK;
+	gpio->gc.can_sleep = true;
+
+	ret = devm_gpiochip_add_data(dev, &gpio->gc, gpio);
+	if (ret)
+		return ret;
+
+	if (has_acpi_companion(dev))
+		acpi_dev_clear_dependencies(ACPI_COMPANION(dev));
+
+	return 0;
+}
+
+static const struct auxiliary_device_id usbio_gpio_id_table[] = {
+	{ "usbio.usbio-gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(auxiliary, usbio_gpio_id_table);
+
+static struct auxiliary_driver usbio_gpio_driver = {
+	.name = USBIO_GPIO_CLIENT,
+	.probe = usbio_gpio_probe,
+	.id_table = usbio_gpio_id_table
+};
+module_auxiliary_driver(usbio_gpio_driver);
+
+MODULE_DESCRIPTION("Intel USBIO GPIO driver");
+MODULE_AUTHOR("Israel Cepeda <israel.a.cepeda.lopez@intel.com>");
+MODULE_AUTHOR("Hans de Goede <hansg@kernel.org>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("USBIO");
-- 
2.51.0

[PATCH v4 3/3] i2c: Add Intel USBIO I2C driver

[Hans de Goede]

From: Israel Cepeda <israel.a.cepeda.lopez@intel.com>

Add a a driver for the I2C auxbus child device of the Intel USBIO USB
IO-expander used by the MIPI cameras on various new (Meteor Lake and
later) Intel laptops.

Co-developed-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Israel Cepeda <israel.a.cepeda.lopez@intel.com>
---
Changes in v2:
- Use new quirks mechanism to treat various revisions differently
- Use __le16, __le32 type + cpu_to_le16() and friends for on wire words
- Some small style fixes from Sakari's review
---
 MAINTAINERS                    |   1 +
 drivers/i2c/busses/Kconfig     |  11 ++
 drivers/i2c/busses/Makefile    |   1 +
 drivers/i2c/busses/i2c-usbio.c | 325 +++++++++++++++++++++++++++++++++
 4 files changed, 338 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-usbio.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 53694bd91861..0f5de266d6df 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12700,6 +12700,7 @@ M:	Hans de Goede <hansg@kernel.org>
 R:	Sakari Ailus <sakari.ailus@linux.intel.com>
 S:	Maintained
 F:	drivers/gpio/gpio-usbio.c
+F:	drivers/i2c/busses/i2c-usbio.c
 F:	drivers/usb/misc/usbio.c
 F:	include/linux/usb/usbio.h
 
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 070d014fdc5d..06b1b702fd7a 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1357,6 +1357,17 @@ config I2C_LJCA
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-ljca.
 
+config I2C_USBIO
+	tristate "Intel USBIO I2C Adapter support"
+	depends on USB_USBIO
+	default USB_USBIO
+	help
+	  Select this option to enable I2C driver for the INTEL
+	  USBIO driver stack.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c_usbio.
+
 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 04db855fdfd6..401a79c9767e 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -135,6 +135,7 @@ 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-$(CONFIG_I2C_USBIO)		+= i2c-usbio.o
 obj-$(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-usbio.c b/drivers/i2c/busses/i2c-usbio.c
new file mode 100644
index 000000000000..10ed183ae881
--- /dev/null
+++ b/drivers/i2c/busses/i2c-usbio.c
@@ -0,0 +1,325 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025 Intel Corporation.
+ * Copyright (c) 2025 Red Hat, Inc.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/types.h>
+#include <linux/usb/usbio.h>
+
+#define I2C_RW_OVERHEAD (sizeof(struct usbio_bulk_packet) + sizeof(struct usbio_i2c_rw))
+
+struct usbio_i2c {
+	struct i2c_adapter adap;
+	struct auxiliary_device *adev;
+	struct usbio_i2c_rw *rwbuf;
+	unsigned long quirks;
+	u32 speed;
+	u16 txbuf_len;
+	u16 rxbuf_len;
+};
+
+static const struct acpi_device_id usbio_i2c_acpi_hids[] = {
+	{ "INTC1008" }, /* MTL */
+	{ "INTC10B3" }, /* ARL */
+	{ "INTC10B6" }, /* LNL */
+	{ "INTC10E3" }, /* PTL */
+	{ }
+};
+
+static const u32 usbio_i2c_speeds[] = {
+	I2C_MAX_STANDARD_MODE_FREQ,
+	I2C_MAX_FAST_MODE_FREQ,
+	I2C_MAX_FAST_MODE_PLUS_FREQ,
+	I2C_MAX_HIGH_SPEED_MODE_FREQ
+};
+
+static void usbio_i2c_uninit(struct i2c_adapter *adap, struct i2c_msg *msg)
+{
+	struct usbio_i2c *i2c = i2c_get_adapdata(adap);
+	struct usbio_i2c_uninit ubuf;
+
+	ubuf.busid = i2c->adev->id;
+	ubuf.config = cpu_to_le16(msg->addr);
+
+	usbio_bulk_msg(i2c->adev, USBIO_PKTTYPE_I2C, USBIO_I2CCMD_UNINIT, true,
+		       &ubuf, sizeof(ubuf), NULL, 0);
+}
+
+static int usbio_i2c_init(struct i2c_adapter *adap, struct i2c_msg *msg)
+{
+	struct usbio_i2c *i2c = i2c_get_adapdata(adap);
+	struct usbio_i2c_init ibuf;
+	void *reply_buf;
+	u16 reply_len;
+	int ret;
+
+	ibuf.busid = i2c->adev->id;
+	ibuf.config = cpu_to_le16(msg->addr);
+	ibuf.speed = cpu_to_le32(i2c->speed);
+
+	if (i2c->quirks & USBIO_QUIRK_I2C_NO_INIT_ACK) {
+		reply_buf = NULL;
+		reply_len = 0;
+	} else {
+		reply_buf = &ibuf;
+		reply_len = sizeof(ibuf);
+	}
+
+	ret = usbio_bulk_msg(i2c->adev, USBIO_PKTTYPE_I2C, USBIO_I2CCMD_INIT, true,
+			     &ibuf, sizeof(ibuf), reply_buf, reply_len);
+	if (ret != sizeof(ibuf))
+		return (ret < 0) ? ret : -EIO;
+
+	return 0;
+}
+
+static int usbio_i2c_read(struct i2c_adapter *adap, struct i2c_msg *msg)
+{
+	struct usbio_i2c *i2c = i2c_get_adapdata(adap);
+	u16 rxchunk = i2c->rxbuf_len - I2C_RW_OVERHEAD;
+	struct usbio_i2c_rw *rbuf = i2c->rwbuf;
+	int ret;
+
+	rbuf->busid = i2c->adev->id;
+	rbuf->config = cpu_to_le16(msg->addr);
+	rbuf->size = cpu_to_le16(msg->len);
+
+	if (msg->len > rxchunk) {
+		/* Need to split the input buffer */
+		u16 len = 0;
+
+		do {
+			if (msg->len - len < rxchunk)
+				rxchunk = msg->len - len;
+
+			ret = usbio_bulk_msg(i2c->adev, USBIO_PKTTYPE_I2C,
+					     USBIO_I2CCMD_READ, true,
+					     rbuf, len == 0 ? sizeof(*rbuf) : 0,
+					     rbuf, sizeof(*rbuf) + rxchunk);
+			if (ret < 0)
+				return ret;
+
+			memcpy(&msg->buf[len], rbuf->data, rxchunk);
+			len += rxchunk;
+		} while (msg->len > len);
+
+		goto out_log;
+	}
+
+	ret = usbio_bulk_msg(i2c->adev, USBIO_PKTTYPE_I2C, USBIO_I2CCMD_READ, true,
+			     rbuf, sizeof(*rbuf), rbuf, sizeof(*rbuf) + msg->len);
+	if (ret != sizeof(*rbuf) + msg->len)
+		return (ret < 0) ? ret : -EIO;
+
+	memcpy(msg->buf, rbuf->data, msg->len);
+
+out_log:
+	dev_dbg(adap->dev.parent, "RD[%d]:%*phN\n", msg->len, msg->len, msg->buf);
+
+	return 0;
+}
+
+static int usbio_i2c_write(struct i2c_adapter *adap, struct i2c_msg *msg)
+{
+	struct usbio_i2c *i2c = i2c_get_adapdata(adap);
+	u16 txchunk = i2c->txbuf_len - I2C_RW_OVERHEAD;
+	struct usbio_i2c_rw *wbuf = i2c->rwbuf;
+	int ret;
+
+	dev_dbg(adap->dev.parent, "WR[%d]:%*phN\n", msg->len, msg->len, msg->buf);
+
+	if (msg->len > txchunk) {
+		/* Need to split the output buffer */
+		u16 len = 0;
+
+		do {
+			wbuf->busid = i2c->adev->id;
+			wbuf->config = cpu_to_le16(msg->addr);
+
+			if (i2c->quirks & USBIO_QUIRK_I2C_USE_CHUNK_LEN)
+				wbuf->size = cpu_to_le16(txchunk);
+			else
+				wbuf->size = cpu_to_le16(msg->len);
+
+			memcpy(wbuf->data, &msg->buf[len], txchunk);
+			len += txchunk;
+
+			ret = usbio_bulk_msg(i2c->adev, USBIO_PKTTYPE_I2C,
+					     USBIO_I2CCMD_WRITE, msg->len == len,
+					     wbuf, sizeof(*wbuf) + txchunk,
+					     wbuf, sizeof(*wbuf));
+			if (ret < 0)
+				return ret;
+
+			if (msg->len - len < txchunk)
+				txchunk = msg->len - len;
+		} while (msg->len > len);
+
+		return 0;
+	}
+
+	wbuf->busid = i2c->adev->id;
+	wbuf->config = cpu_to_le16(msg->addr);
+	wbuf->size = cpu_to_le16(msg->len);
+	memcpy(wbuf->data, msg->buf, msg->len);
+
+	ret = usbio_bulk_msg(i2c->adev, USBIO_PKTTYPE_I2C, USBIO_I2CCMD_WRITE, true,
+			     wbuf, sizeof(*wbuf) + msg->len, wbuf, sizeof(*wbuf));
+	if (ret != sizeof(*wbuf) || le16_to_cpu(wbuf->size) != msg->len)
+		return (ret < 0) ? ret : -EIO;
+
+	return 0;
+}
+
+static int usbio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	struct usbio_i2c *i2c = i2c_get_adapdata(adap);
+	int ret;
+
+	usbio_acquire(i2c->adev);
+
+	ret = usbio_i2c_init(adap, msgs);
+	if (ret)
+		goto out_release;
+
+	for (int i = 0; i < num; ret = ++i) {
+		if (msgs[i].flags & I2C_M_RD)
+			ret = usbio_i2c_read(adap, &msgs[i]);
+		else
+			ret = usbio_i2c_write(adap, &msgs[i]);
+
+		if (ret)
+			break;
+	}
+
+	usbio_i2c_uninit(adap, msgs);
+
+out_release:
+	usbio_release(i2c->adev);
+
+	return ret;
+}
+
+static u32 usbio_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_adapter_quirks usbio_i2c_quirks = {
+	.flags = I2C_AQ_NO_REP_START,
+	.max_read_len = SZ_4K,
+	.max_write_len = SZ_4K,
+};
+
+static const struct i2c_adapter_quirks usbio_i2c_quirks_max_rw_len52 = {
+	.flags = I2C_AQ_NO_REP_START,
+	.max_read_len = 52,
+	.max_write_len = 52,
+};
+
+static const struct i2c_algorithm usbio_i2c_algo = {
+	.master_xfer = usbio_i2c_xfer,
+	.functionality = usbio_i2c_func,
+};
+
+static int usbio_i2c_probe(struct auxiliary_device *adev,
+			   const struct auxiliary_device_id *adev_id)
+{
+	struct usbio_i2c_bus_desc *i2c_desc;
+	struct device *dev = &adev->dev;
+	struct usbio_i2c *i2c;
+	u32 max_speed;
+	int ret;
+
+	i2c_desc = dev_get_platdata(dev);
+	if (!i2c_desc)
+		return -EINVAL;
+
+	i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
+
+	i2c->adev = adev;
+
+	usbio_acpi_bind(i2c->adev, usbio_i2c_acpi_hids);
+	usbio_get_txrxbuf_len(i2c->adev, &i2c->txbuf_len, &i2c->rxbuf_len);
+
+	i2c->rwbuf = devm_kzalloc(dev, max(i2c->txbuf_len, i2c->rxbuf_len), GFP_KERNEL);
+	if (!i2c->rwbuf)
+		return -ENOMEM;
+
+	i2c->quirks = usbio_get_quirks(i2c->adev);
+
+	max_speed = usbio_i2c_speeds[i2c_desc->caps & USBIO_I2C_BUS_MODE_CAP_MASK];
+	if (max_speed < I2C_MAX_FAST_MODE_FREQ &&
+	    (i2c->quirks & USBIO_QUIRK_I2C_ALLOW_400KHZ))
+		max_speed = I2C_MAX_FAST_MODE_FREQ;
+
+	i2c->speed = i2c_acpi_find_bus_speed(dev);
+	if (!i2c->speed)
+		i2c->speed = I2C_MAX_STANDARD_MODE_FREQ;
+	else if (i2c->speed > max_speed) {
+		dev_warn(dev, "Invalid speed %u adjusting to bus max %u\n",
+			 i2c->speed, max_speed);
+		i2c->speed = max_speed;
+	}
+
+	i2c->adap.owner = THIS_MODULE;
+	i2c->adap.class = I2C_CLASS_HWMON;
+	i2c->adap.dev.parent = dev;
+	i2c->adap.algo = &usbio_i2c_algo;
+
+	if (i2c->quirks & USBIO_QUIRK_I2C_MAX_RW_LEN_52)
+		i2c->adap.quirks = &usbio_i2c_quirks_max_rw_len52;
+	else
+		i2c->adap.quirks = &usbio_i2c_quirks;
+
+	snprintf(i2c->adap.name, sizeof(i2c->adap.name), "%s.%d",
+		 USBIO_I2C_CLIENT, i2c->adev->id);
+
+	device_set_node(&i2c->adap.dev, dev_fwnode(&adev->dev));
+
+	auxiliary_set_drvdata(adev, i2c);
+	i2c_set_adapdata(&i2c->adap, i2c);
+
+	ret = i2c_add_adapter(&i2c->adap);
+	if (ret)
+		return ret;
+
+	if (has_acpi_companion(&i2c->adap.dev))
+		acpi_dev_clear_dependencies(ACPI_COMPANION(&i2c->adap.dev));
+
+	return 0;
+}
+
+static void usbio_i2c_remove(struct auxiliary_device *adev)
+{
+	struct usbio_i2c *i2c = auxiliary_get_drvdata(adev);
+
+	i2c_del_adapter(&i2c->adap);
+}
+
+static const struct auxiliary_device_id usbio_i2c_id_table[] = {
+	{ "usbio.usbio-i2c" },
+	{ }
+};
+MODULE_DEVICE_TABLE(auxiliary, usbio_i2c_id_table);
+
+static struct auxiliary_driver usbio_i2c_driver = {
+	.name = USBIO_I2C_CLIENT,
+	.probe = usbio_i2c_probe,
+	.remove = usbio_i2c_remove,
+	.id_table = usbio_i2c_id_table
+};
+module_auxiliary_driver(usbio_i2c_driver);
+
+MODULE_DESCRIPTION("Intel USBIO I2C driver");
+MODULE_AUTHOR("Israel Cepeda <israel.a.cepeda.lopez@intel.com>");
+MODULE_AUTHOR("Hans de Goede <hansg@kernel.org>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("USBIO");
-- 
2.51.0

Re: [PATCH v4 2/3] gpio: Add Intel USBIO GPIO driver

[Linus Walleij]

Hi Hans,

thanks for your patch!

On Wed, Sep 10, 2025 at 3:40 PM Hans de Goede <hansg@kernel.org> wrote:

> From: Israel Cepeda <israel.a.cepeda.lopez@intel.com>
>
> Add a a driver for the GPIO auxbus child device of the Intel USBIO USB
> IO-expander used by the MIPI cameras on various new (Meteor Lake and
> later) Intel laptops.
>
> Co-developed-by: Hans de Goede <hansg@kernel.org>
> Signed-off-by: Hans de Goede <hansg@kernel.org>
> Signed-off-by: Israel Cepeda <israel.a.cepeda.lopez@intel.com>
(...)

> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -1448,6 +1448,17 @@ config GPIO_LJCA
>           This driver can also be built as a module. If so, the module
>           will be called gpio-ljca.
>
> +config GPIO_USBIO
> +       tristate "Intel USBIO GPIO support"
> +       depends on USB_USBIO
> +       default USB_USBIO
> +       help
> +         Select this option to enable GPIO driver for the INTEL
> +         USBIO driver stack.
> +
> +         This driver can also be built as a module. If so, the module
> +         will be called gpio_usbio.

This is in the wrong submenu (and the GPIO_LJCA is in the
wrong place too, but that's not your problem...)

We have:

menu "USB GPIO expanders"
        depends on USB

So put it in this submeny.

Other than that it looks good, so with that change:
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH v4 3/3] i2c: Add Intel USBIO I2C driver

[Wolfram Sang]

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Hi Hans,

> +out_log:
> +	dev_dbg(adap->dev.parent, "RD[%d]:%*phN\n", msg->len, msg->len, msg->buf);

I think this...

> +
> +	return 0;
> +}
> +
> +static int usbio_i2c_write(struct i2c_adapter *adap, struct i2c_msg *msg)
> +{
> +	struct usbio_i2c *i2c = i2c_get_adapdata(adap);
> +	u16 txchunk = i2c->txbuf_len - I2C_RW_OVERHEAD;
> +	struct usbio_i2c_rw *wbuf = i2c->rwbuf;
> +	int ret;
> +
> +	dev_dbg(adap->dev.parent, "WR[%d]:%*phN\n", msg->len, msg->len, msg->buf);

... and this dbg can go. The tracepoints we have should do?

> +static u32 usbio_i2c_func(struct i2c_adapter *adap)
> +{
> +	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
> +}

How did you test 10 bit addresses? I have never seen them in the wild?

Did you also check SMBUS_QUICK? 'i2cdetect' uses it by default.

Does the underlying USBIO driver use usb_control_msg? If so, we need to
disable zero length read messages. See [1] for a reference.

Rest looks good to me!

[1] https://lore.kernel.org/all/20250522064234.3721-2-wsa+renesas@sang-engineering.com/


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Re: [PATCH v4 2/3] gpio: Add Intel USBIO GPIO driver

[Hans de Goede]

Hi,

On 10-Sep-25 11:41 PM, Linus Walleij wrote:
> Hi Hans,
> 
> thanks for your patch!
> 
> On Wed, Sep 10, 2025 at 3:40 PM Hans de Goede <hansg@kernel.org> wrote:
> 
>> From: Israel Cepeda <israel.a.cepeda.lopez@intel.com>
>>
>> Add a a driver for the GPIO auxbus child device of the Intel USBIO USB
>> IO-expander used by the MIPI cameras on various new (Meteor Lake and
>> later) Intel laptops.
>>
>> Co-developed-by: Hans de Goede <hansg@kernel.org>
>> Signed-off-by: Hans de Goede <hansg@kernel.org>
>> Signed-off-by: Israel Cepeda <israel.a.cepeda.lopez@intel.com>
> (...)
> 
>> --- a/drivers/gpio/Kconfig
>> +++ b/drivers/gpio/Kconfig
>> @@ -1448,6 +1448,17 @@ config GPIO_LJCA
>>           This driver can also be built as a module. If so, the module
>>           will be called gpio-ljca.
>>
>> +config GPIO_USBIO
>> +       tristate "Intel USBIO GPIO support"
>> +       depends on USB_USBIO
>> +       default USB_USBIO
>> +       help
>> +         Select this option to enable GPIO driver for the INTEL
>> +         USBIO driver stack.
>> +
>> +         This driver can also be built as a module. If so, the module
>> +         will be called gpio_usbio.
> 
> This is in the wrong submenu (and the GPIO_LJCA is in the
> wrong place too, but that's not your problem...)
> 
> We have:
> 
> menu "USB GPIO expanders"
>         depends on USB
> 
> So put it in this submeny.
> 
> Other than that it looks good, so with that change:
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Thank you, I'll fix this for v5 and add your R-b.

Regards,

Hans

Re: [PATCH v4 3/3] i2c: Add Intel USBIO I2C driver

[Hans de Goede]

Hi Wolfram,

Thank you for the review.

On 10-Sep-25 11:54 PM, Wolfram Sang wrote:
> Hi Hans,
> 
>> +out_log:
>> +	dev_dbg(adap->dev.parent, "RD[%d]:%*phN\n", msg->len, msg->len, msg->buf);
> 
> I think this...
> 
>> +
>> +	return 0;
>> +}
>> +
>> +static int usbio_i2c_write(struct i2c_adapter *adap, struct i2c_msg *msg)
>> +{
>> +	struct usbio_i2c *i2c = i2c_get_adapdata(adap);
>> +	u16 txchunk = i2c->txbuf_len - I2C_RW_OVERHEAD;
>> +	struct usbio_i2c_rw *wbuf = i2c->rwbuf;
>> +	int ret;
>> +
>> +	dev_dbg(adap->dev.parent, "WR[%d]:%*phN\n", msg->len, msg->len, msg->buf);
> 
> ... and this dbg can go. The tracepoints we have should do?

Ack, I've dropped both for the upcoming v5.

>> +static u32 usbio_i2c_func(struct i2c_adapter *adap)
>> +{
>> +	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
>> +}
> 
> How did you test 10 bit addresses? I have never seen them in the wild?

I did not test 10 bit addresses. This was there in the original code
from Intel.

> Did you also check SMBUS_QUICK? 'i2cdetect' uses it by default.

I just tested this and this indeed does not work, when doing
a 0 byte write then waiting for the chip to respond times-out and
further i2c transfers after that also fail until the chip is
power-cycled.

> Does the underlying USBIO driver use usb_control_msg? If so, we need to
> disable zero length read messages. See [1] for a reference.

No it uses bulk messages.

Still based on the no support for writing 0 byte messages, I've tried
a 0 byte read, since the 0 byte write was not liked much and doing
i2ctransfer ... r0@0x10 results in the same problem.

So I'll add I2C_AQ_NO_ZERO_LEN to the quirks.

Regards,

Hans

Re: [PATCH v4 3/3] i2c: Add Intel USBIO I2C driver

[Wolfram Sang]

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> > How did you test 10 bit addresses? I have never seen them in the wild?
> 
> I did not test 10 bit addresses. This was there in the original code
> from Intel.

I suggest to drop it. There is no code handling the I2C_M_TEN flag which
should be handled if support is advertised.

> So I'll add I2C_AQ_NO_ZERO_LEN to the quirks.

Ack.


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Re: [PATCH v4 3/3] i2c: Add Intel USBIO I2C driver

[Hans de Goede]

Hi,

On 11-Sep-25 4:43 PM, Wolfram Sang wrote:
> 
>>> How did you test 10 bit addresses? I have never seen them in the wild?
>>
>> I did not test 10 bit addresses. This was there in the original code
>> from Intel.
> 
> I suggest to drop it. There is no code handling the I2C_M_TEN flag which
> should be handled if support is advertised.

Ok, I'll drop this for v6. Hopefully that will be the last
version of this series then.

Regards,

Hans