usb/gpio/i2c: Add Intel USBIO USB IO-expander drivers

From: Israel Cepeda <[email protected]>

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 <[email protected]>

Signed-off-by Hans de Goede <[email protected]>

Signed-off-by Israel Cepeda <[email protected]>

---
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 | 267 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 280 insertions(+)
 create mode 100644 drivers/gpio/gpio-usbio.c

MAINTAINERS +1 -0

index 3410699ad0b2..53694bd91861 100644
@@ -12699,6 +12699,7 @@ M:	Israel Cepeda <[email protected]>
 M:	Hans de Goede <[email protected]>
 R:	Sakari Ailus <[email protected]>
 S:	Maintained
+F:	drivers/gpio/gpio-usbio.c
 F:	drivers/usb/misc/usbio.c
 F:	include/linux/usb/usbio.h
 

drivers/gpio/Kconfig +11 -0

index e43abb322fa6..5d3ca3dd2687 100644
@@ -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

drivers/gpio/Makefile +1 -0

index 379f55e9ed1e..8c55e2d5de42 100644
@@ -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

drivers/gpio/gpio-usbio.c new file +38 -0

new file mode 100644
index 000000000000..1df32105cf51
@@ -0,0 +1,267 @@
+// 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/dev_printk.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 bool usbio_gpio_get_bank_and_pin(struct gpio_chip *gc, unsigned int offset,
+					struct usbio_gpio_bank **bank_ret,

drivers/gpio/gpio-usbio.c new file +103 -0

+	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;
+	return true;
+}
+
+static int usbio_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	struct usbio_gpio_bank *bank;
+	unsigned int pin;
+	u8 cfg;
+
+	if (!usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin))
+		return -EINVAL;
+
+	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;
+
+	if (!usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin))
+		return -EINVAL;
+
+	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;
+
+	if (!usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin))
+		return -EINVAL;
+
+	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;
+
+	if (!usbio_gpio_get_bank_and_pin(gc, offset, &bank, &pin))
+		return -EINVAL;
+
+	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)

drivers/gpio/gpio-usbio.c new file +61 -0

+}
+
+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;

drivers/gpio/gpio-usbio.c new file +35 -1

+	if (ret)
+		return ret;
+
+	if (has_acpi_companion(dev))
+		acpi_dev_clear_dependencies(ACPI_COMPANION(dev));
+
+	return 0;
+}
+
+static void usbio_gpio_remove(struct auxiliary_device *adev)
+{
+	struct usbio_gpio *gpio = auxiliary_get_drvdata(adev);
+
+	gpiochip_remove(&gpio->gc);
+}
+
+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,
+	.remove = usbio_gpio_remove,
+	.id_table = usbio_gpio_id_table
+};
+module_auxiliary_driver(usbio_gpio_driver);
+
+MODULE_DESCRIPTION("Intel USBIO GPIO driver");
+MODULE_AUTHOR("Israel Cepeda <[email protected]>");
+MODULE_AUTHOR("Hans de Goede <[email protected]>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("USBIO");
--

2.51.0

Quoted 119 lines · Hans de Goede

From: Israel Cepeda <[email protected]>

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 <[email protected]>

Signed-off-by Hans de Goede <[email protected]>

Signed-off-by Israel Cepeda <[email protected]>

---
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 | 267 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 280 insertions(+)
 create mode 100644 drivers/gpio/gpio-usbio.c

MAINTAINERS +1 -0

index 3410699ad0b2..53694bd91861 100644
@@ -12699,6 +12699,7 @@ M:	Israel Cepeda <[email protected]>
 M:	Hans de Goede <[email protected]>
 R:	Sakari Ailus <[email protected]>
 S:	Maintained
+F:	drivers/gpio/gpio-usbio.c
 F:	drivers/usb/misc/usbio.c
 F:	include/linux/usb/usbio.h
 

drivers/gpio/Kconfig +11 -0

index e43abb322fa6..5d3ca3dd2687 100644
@@ -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

drivers/gpio/Makefile +1 -0

index 379f55e9ed1e..8c55e2d5de42 100644
@@ -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

drivers/gpio/gpio-usbio.c new file +42 -0

new file mode 100644
index 000000000000..1df32105cf51
@@ -0,0 +1,267 @@
+// 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/dev_printk.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 bool 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;

drivers/gpio/gpio-usbio.c line 48

Quoted 6 lines

drivers/gpio/gpio-usbio.c new file +6 -0

+	struct usbio_gpio_bank *bank;
+	unsigned int pin;
+
+	if (offset >= gc->ngpio)
+		return false;
+

No need for that, GPIO core will make sure this never happens.

Quoted 11 lines

drivers/gpio/gpio-usbio.c new file +11 -0

+	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;
+	return true;
+}

Quoted 6 lines

drivers/gpio/gpio-usbio.c new file +6 -0

+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,

drivers/gpio/gpio-usbio.c line 161

Quoted 6 lines

drivers/gpio/gpio-usbio.c new file +6 -0

+				       USBIO_GPIO_SET_PINMOD(USBIO_GPIO_PINMOD_OUTPUT));
+	if (ret)
+		return ret;
+
+	usbio_gpio_set(gc, offset, value);
+	return 0;

return usbio_gpio_set(gc, offset, value);?

Quoted 1 line

+}

Quoted 3 lines

drivers/gpio/gpio-usbio.c new file +3 -0

+static int usbio_gpio_probe(struct auxiliary_device *adev,
+		const struct auxiliary_device_id *adev_id)
+{

drivers/gpio/gpio-usbio.c line 232

Quoted 3 lines

drivers/gpio/gpio-usbio.c new file +3 -0

+	auxiliary_set_drvdata(adev, gpio);
+
+	ret = gpiochip_add_data(&gpio->gc, gpio);

Please use the devres variant, you'll be able to drop the remove() callback.

Quoted 33 lines

drivers/gpio/gpio-usbio.c new file +33 -0

+	if (ret)
+		return ret;
+
+	if (has_acpi_companion(dev))
+		acpi_dev_clear_dependencies(ACPI_COMPANION(dev));
+
+	return 0;
+}
+
+static void usbio_gpio_remove(struct auxiliary_device *adev)
+{
+	struct usbio_gpio *gpio = auxiliary_get_drvdata(adev);
+
+	gpiochip_remove(&gpio->gc);
+}
+
+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,
+	.remove = usbio_gpio_remove,
+	.id_table = usbio_gpio_id_table
+};
+module_auxiliary_driver(usbio_gpio_driver);
+
+MODULE_DESCRIPTION("Intel USBIO GPIO driver");
+MODULE_AUTHOR("Israel Cepeda <[email protected]>");
+MODULE_AUTHOR("Hans de Goede <[email protected]>");

Quoted 6 lines

drivers/gpio/gpio-usbio.c new file +2 -1

+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("USBIO");
--

2.51.0

Looks good otherwise.

Thank you I'll go and preparare a standalone v3 (since the other 2 patches have no reviews yet).

As mentioned in the cover-letter it is probably easiest if Greg merges the entire series through his usb tree once everything has been reviewed.

Once I've send it, can you please ack v3 for merging through Greg's USB tree?

Quoted 4 lines · Hans de Goede

Thank you I'll go and preparare a standalone v3 (since the other 2 patches have no reviews yet).

Please, don't do this. This is a great way to confuse everyone involved. :(

Quoted 7 lines

As mentioned in the cover-letter it is probably easiest if Greg merges the entire series through his usb tree once everything has been reviewed.

Once I've send it, can you please ack v3 for merging through Greg's USB tree?

I would prefer to ack a patch that's part of a proper series, this split makes no sense.

Hi All,

Here is v2 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 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.

Quoted 27 lines · Hans de Goede

Hi All,

Here is v2 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 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.

Quoted 4 lines

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.

Either is fine with me, patch 1 looks good enough for me to queue it up now.

Let me know what you want me to do.

Hi Greg,

Quoted 28 lines · Greg Kroah-Hartman

Quoted 27 lines · Hans de Goede

Hi All,

Here is v2 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 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.

Quoted 7 lines

Quoted 4 lines

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.

Either is fine with me, patch 1 looks good enough for me to queue it up now.

That is good news.

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Let me know what you want me to do.

I've done a v3 of just the GPIO patch since Bart had some review-comments there. Bart still had 2 more small remarks on the v3 GPIO patch. So I'm about to send out a v4 series (with just changes to the GPIO driver compared to this v2).

I hope Bart will be happy with v4, so then Bart can let you know if he prefers an immutable tag, or wants you to merge the GPIO driver into usb-next.

Once it is clear how to proceed with the GPIO driver I suggest that we get both of them merged and then wait for feedback on the I2C driver.

Regards,

Hans