On platforms where ACPI is designed for use with Windows, resources
that are intended to be consumed by sensor devices are sometimes in
the _CRS of a dummy INT3472 device upon which the sensor depends. This
driver binds to the dummy acpi device (which does not represent a
physical PMIC) and maps them into GPIO lines and regulators for use by
the sensor device instead.
Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
---
Changes since RFC v3:
- Patch introduced
This patch contains the bits of this process that we're least sure about.
The sensors in scope for this work are called out as dependent (in their
DSDT entry's _DEP) on a device with _HID INT3472. These come in at least
2 kinds; those with an I2cSerialBusV2 entry (which we presume therefore
are legitimate tps68470 PMICs that need handling by those drivers - work
on that in the future). And those without an I2C device. For those without
an I2C device they instead have an array of GPIO pins defined in _CRS. So
for example, my Lenovo Miix 510's OVTI2680 sensor is dependent on one of
the _latter_ kind of INT3472 devices, with this _CRS:
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
{
Name (SBUF, ResourceTemplate ()
{
GpioIo (Exclusive, PullDefault, 0x0000, 0x0000,
IoRestrictionOutputOnly, "\\_SB.PCI0.GPI0",
0x00, ResourceConsumer, ,
)
{ // Pin list
0x0079
}
GpioIo (Exclusive, PullDefault, 0x0000, 0x0000,
IoRestrictionOutputOnly, "\\_SB.PCI0.GPI0",
0x00, ResourceConsumer, ,
)
{ // Pin list
0x007A
}
GpioIo (Exclusive, PullDefault, 0x0000, 0x0000,
IoRestrictionOutputOnly, "\\_SB.PCI0.GPI0",
0x00, ResourceConsumer, ,
)
{ // Pin list
0x008F
}
})
Return (SBUF) /* \_SB_.PCI0.PMI1._CRS.SBUF */
}
and the same device has a _DSM Method, which returns 32-bit ints where
the second lowest byte we noticed to match the pin numbers of the GPIO
lines:
Method (_DSM, 4, NotSerialized) // _DSM: Device-Specific Method
{
If ((Arg0 == ToUUID ("79234640-9e10-4fea-a5c1-b5aa8b19756f")))
{
If ((Arg2 == One))
{
Return (0x03)
}
If ((Arg2 == 0x02))
{
Return (0x01007900)
}
If ((Arg2 == 0x03))
{
Return (0x01007A0C)
}
If ((Arg2 == 0x04))
{
Return (0x01008F01)
}
}
Return (Zero)
}
We know that at least some of those pins have to be toggled active for the
sensor devices to be available in i2c, so the conclusion we came to was
that those GPIO entries assigned to the INT3472 device actually represent
GPIOs and regulators to be consumed by the sensors themselves. Tsuchiya
noticed that the lowest byte in the return values of the _DSM method
seemed to represent the type or function of the GPIO line, and we
confirmed that by testing on each surface device that GPIO lines where the
low byte in the _DSM entry for that pin was 0x0d controlled the privacy
LED of the cameras.
We're guessing as to the exact meaning of the function byte, but I
conclude they're something like this:
0x00 - probably a reset GPIO
0x01 - regulator for the sensor
0x0c - regulator for the sensor
0x0b - regulator again, but for a VCM or EEPROM
0x0d - privacy led (only one we're totally confident of since we can see
it happen!)
After much internal debate I decided to write this as a standalone
acpi_driver. Alternative options we considered:
1. Squash all this into the cio2-bridge code, which I did originally write
but decided I didn't like.
2. Extend the existing tps68470 mfd driver...they share an ACPI ID so this
kinda makes sense, but ultimately given there is no actual physical
tps68470 in the scenario this patch handles I decided I didn't like this
either.
MAINTAINERS | 7 +
drivers/media/pci/intel/ipu3/Kconfig | 14 +
drivers/media/pci/intel/ipu3/Makefile | 1 +
drivers/media/pci/intel/ipu3/int3472.c | 381 +++++++++++++++++++++++++
drivers/media/pci/intel/ipu3/int3472.h | 96 +++++++
5 files changed, 499 insertions(+)
create mode 100644 drivers/media/pci/intel/ipu3/int3472.c
create mode 100644 drivers/media/pci/intel/ipu3/int3472.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 188559a0a610..d73471f9c2a3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8753,6 +8753,13 @@ L: linux-crypto@xxxxxxxxxxxxxxx
S: Maintained
F: drivers/crypto/inside-secure/
+INT3472 ACPI DEVICE DRIVER
+M: Daniel Scally <djrscally@xxxxxxxxx>
+L: linux-media@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/media/pci/intel/ipu3/int3472.c
+F: drivers/media/pci/intel/ipu3/int3472.h
+
INTEGRITY MEASUREMENT ARCHITECTURE (IMA)
M: Mimi Zohar <zohar@xxxxxxxxxxxxx>
M: Dmitry Kasatkin <dmitry.kasatkin@xxxxxxxxx>
diff --git a/drivers/media/pci/intel/ipu3/Kconfig b/drivers/media/pci/intel/ipu3/Kconfig
index 2b3350d042be..9dd3b280f821 100644
--- a/drivers/media/pci/intel/ipu3/Kconfig
+++ b/drivers/media/pci/intel/ipu3/Kconfig
@@ -34,3 +34,17 @@ config CIO2_BRIDGE
- Dell 7285
If in doubt, say N here.
+
+config INT3472
+ tristate "INT3472 Dummy ACPI Device Driver"
+ depends on VIDEO_IPU3_CIO2
+ depends on ACPI && REGULATOR && GPIOLIB
+ help
+ This module provides an ACPI driver for INT3472 devices that do not
+ represent an actual physical tps68470 device.
+
+ Say Y here if your device is a detachable / hybrid laptop that comes
+ with Windows installed by the OEM.
+ The module will be called int3472.
+
+ If in doubt, say N here.
diff --git a/drivers/media/pci/intel/ipu3/Makefile b/drivers/media/pci/intel/ipu3/Makefile
index 933777e6ea8a..2285947b2bd2 100644
--- a/drivers/media/pci/intel/ipu3/Makefile
+++ b/drivers/media/pci/intel/ipu3/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_VIDEO_IPU3_CIO2) += ipu3-cio2.o
+obj-$(CONFIG_INT3472) += int3472.o
ipu3-cio2-y += ipu3-cio2-main.o
ipu3-cio2-$(CONFIG_CIO2_BRIDGE) += cio2-bridge.o
diff --git a/drivers/media/pci/intel/ipu3/int3472.c b/drivers/media/pci/intel/ipu3/int3472.c
new file mode 100644
index 000000000000..6b0be75f7f35
--- /dev/null
+++ b/drivers/media/pci/intel/ipu3/int3472.c
@@ -0,0 +1,381 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Author: Dan Scally <djrscally@xxxxxxxxx> */
+#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/machine.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/regulator/driver.h>
+
+#include "int3472.h"
+
+/*
+ * The regulators have to have .ops to be valid, but the only ops we actually
+ * support are .enable and .disable which are handled via .ena_gpiod. Pass an
+ * empty struct to clear the check without lying about capabilities.
+ */
+static const struct regulator_ops int3472_gpio_regulator_ops = { 0 };
+
+static int int3472_map_gpio_to_sensor(struct int3472_device *int3472,
+ struct acpi_resource *ares, char *func)
+{
+ char *path = ares->data.gpio.resource_source.string_ptr;
+ struct gpiod_lookup table_entry;
+ struct acpi_device *adev;
+ acpi_handle handle;
+ acpi_status status;
+ int ret;
+
+ /* Make sure we don't overflow, and leave room for a terminator */
+ if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
+ dev_warn(&int3472->sensor->dev, "Too many GPIOs mapped\n");
+ return -EINVAL;
+ }
+
+ /* Fetch ACPI handle for the GPIO chip */
+ status = acpi_get_handle(NULL, path, &handle);
+ if (ACPI_FAILURE(status))
+ return -EINVAL;
+
+ ret = acpi_bus_get_device(handle, &adev);
+ if (ret)
+ return -ENODEV;
+
+ table_entry = (struct gpiod_lookup)GPIO_LOOKUP_IDX(acpi_dev_name(adev),
+ ares->data.gpio.pin_table[0],
+ func, 0, GPIO_ACTIVE_HIGH);
+
+ memcpy(&int3472->gpios.table[int3472->n_sensor_gpios], &table_entry,
+ sizeof(table_entry));
+ int3472->n_sensor_gpios++;
+
+ return 0;
+}
+
+static struct int3472_sensor_regulator_map *
+int3472_get_sensor_supply_map(struct int3472_device *int3472)
+{
+ struct int3472_sensor_regulator_map *ret;
+ union acpi_object *obj;
+ unsigned int i;
+
+ /*
+ * Sensor modules seem to be identified by a unique string. We use that
+ * to make sure we pass the right device and supply names to the new
+ * regulator's consumer_supplies
+ */
+ obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
+ &cio2_sensor_module_guid, 0x00,
+ 0x01, NULL, ACPI_TYPE_STRING);
+
+ if (!obj) {
+ dev_err(&int3472->sensor->dev,
+ "Failed to get sensor module string from _DSM\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ if (obj->string.type != ACPI_TYPE_STRING) {
+ dev_err(&int3472->sensor->dev,
+ "Sensor _DSM returned a non-string value\n");
+ ret = ERR_PTR(-EINVAL);
+ goto out_free_obj;
+ }
+
+ ret = ERR_PTR(-ENODEV);
+ for (i = 0; i < ARRAY_SIZE(int3472_sensor_regulator_maps); i++) {
+ if (!strcmp(int3472_sensor_regulator_maps[i].sensor_module_name,
+ obj->string.pointer)) {
+ ret = &int3472_sensor_regulator_maps[i];
+ goto out_free_obj;
+ }
+ }
+
+out_free_obj:
+ ACPI_FREE(obj);
+ return ret;
+}
+
+static int int3472_register_regulator(struct int3472_device *int3472,
+ struct acpi_resource *ares)
+{
+ char *path = ares->data.gpio.resource_source.string_ptr;
+ struct int3472_sensor_regulator_map *regulator_map;
+ struct regulator_init_data init_data = { };
+ struct int3472_gpio_regulator *regulator;
+ struct regulator_config cfg = { };
+ int ret;
+
+ /*
+ * We lookup supply names from machine specific tables, based on a
+ * unique identifier in the sensor's _DSM
+ */
+ regulator_map = int3472_get_sensor_supply_map(int3472);
+ if (IS_ERR_OR_NULL(regulator_map)) {
+ dev_err(&int3472->sensor->dev,
+ "Found no supplies defined for this sensor\n");
+ return PTR_ERR(regulator_map);
+ }
+
+ if (int3472->n_regulators >= regulator_map->n_supplies) {
+ dev_err(&int3472->sensor->dev,
+ "All known supplies are already mapped\n");
+ return -EINVAL;
+ }
+
+ init_data.supply_regulator = NULL;
+ init_data.constraints.valid_ops_mask = REGULATOR_CHANGE_STATUS;
+ init_data.num_consumer_supplies = 1;
+ init_data.consumer_supplies = ®ulator_map->supplies[int3472->n_regulators];
+
+ regulator = kmalloc(sizeof(*regulator), GFP_KERNEL);
+ if (!regulator)
+ return -ENOMEM;
+
+ snprintf(regulator->regulator_name, GPIO_REGULATOR_NAME_LENGTH,
+ "gpio-regulator-%d", int3472->n_regulators);
+ snprintf(regulator->supply_name, GPIO_REGULATOR_SUPPLY_NAME_LENGTH,
+ "supply-%d", int3472->n_regulators);
+
+ regulator->rdesc = INT3472_REGULATOR(regulator->regulator_name,
+ regulator->supply_name,
+ int3472->n_regulators,
+ &int3472_gpio_regulator_ops);
+
+ regulator->gpio = acpi_get_gpiod(path, ares->data.gpio.pin_table[0]);
+ if (IS_ERR(regulator->gpio)) {
+ ret = PTR_ERR(regulator->gpio);
+ goto err_free_regulator;
+ }
+
+ cfg.dev = &int3472->adev->dev;
+ cfg.init_data = &init_data;
+ cfg.ena_gpiod = regulator->gpio;
+
+ regulator->rdev = regulator_register(®ulator->rdesc, &cfg);
+ if (IS_ERR(regulator->rdev)) {
+ ret = PTR_ERR(regulator->rdev);
+ goto err_free_gpio;
+ }
+
+ list_add(®ulator->list, &int3472->regulators);
+ int3472->n_regulators++;
+
+ return 0;
+
+err_free_gpio:
+ gpiod_put(regulator->gpio);
+err_free_regulator:
+ kfree(regulator);
+
+ return ret;
+}
+
+static int int3472_handle_gpio_resources(struct acpi_resource *ares,
+ void *data)
+{
+ struct int3472_device *int3472 = data;
+ union acpi_object *obj;
+ int ret = 0;
+
+ if (ares->type != ACPI_RESOURCE_TYPE_GPIO ||
+ ares->data.gpio.connection_type != ACPI_RESOURCE_GPIO_TYPE_IO)
+ return EINVAL; /* Deliberately positive */
+
+ /*
+ * n_gpios + 2 because the index of this _DSM function is 1-based and
+ * the first function is just a count.
+ */
+ obj = acpi_evaluate_dsm_typed(int3472->adev->handle,
+ &int3472_gpio_guid, 0x00,
+ int3472->n_gpios + 2,
+ NULL, ACPI_TYPE_INTEGER);
+
+ if (!obj) {
+ dev_warn(&int3472->adev->dev,
+ "No _DSM entry for this GPIO pin\n");
+ return ENODEV;
+ }
+
+ switch (obj->integer.value & 0xff) { /* low byte holds type data */
+ case 0x00: /* Purpose unclear, possibly a reset GPIO pin */
+ ret = int3472_map_gpio_to_sensor(int3472, ares, "reset");
+ if (ret)
+ dev_warn(&int3472->adev->dev,
+ "Failed to map reset pin to sensor\n");
+
+ break;
+ case 0x01: /* Power regulators (we think) */
+ case 0x0c:
+ ret = int3472_register_regulator(int3472, ares);
+ if (ret)
+ dev_warn(&int3472->adev->dev,
+ "Failed to map regulator to sensor\n");
+
+ break;
+ case 0x0b: /* Power regulators, but to a device separate to sensor */
+ ret = int3472_register_regulator(int3472, ares);
+ if (ret)
+ dev_warn(&int3472->adev->dev,
+ "Failed to map regulator to sensor\n");
+
+ break;
+ case 0x0d: /* Indicator LEDs */
+ ret = int3472_map_gpio_to_sensor(int3472, ares, "indicator-led");
+ if (ret)
+ dev_warn(&int3472->adev->dev,
+ "Failed to map indicator led to sensor\n");
+
+ break;
+ default:
+ /* if we've gotten here, we're not sure what they are yet */
+ dev_warn(&int3472->adev->dev,
+ "GPIO type 0x%llx unknown; the sensor may not work\n",
+ (obj->integer.value & 0xff));
+ ret = EINVAL;
+ }
+
+ int3472->n_gpios++;
+ ACPI_FREE(obj);
+ return abs(ret);
+}
+
+static void int3472_parse_crs(struct int3472_device *int3472)
+{
+ struct list_head resource_list;
+
+ INIT_LIST_HEAD(&resource_list);
+
+ acpi_dev_get_resources(int3472->adev, &resource_list,
+ int3472_handle_gpio_resources, int3472);
+
+ acpi_dev_free_resource_list(&resource_list);
+ gpiod_add_lookup_table(&int3472->gpios);
+}
+
+static int int3472_add(struct acpi_device *adev)
+{
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct int3472_device *int3472;
+ struct int3472_cldb cldb;
+ union acpi_object *obj;
+ acpi_status status;
+ int ret = 0;
+
+ /*
+ * This driver is only intended to support "dummy" INT3472 devices
+ * which appear in ACPI designed for Windows. These are distinguishable
+ * from INT3472 entries representing an actual tps68470 PMIC through
+ * the presence of a CLDB buffer with a particular value set.
+ */
+ status = acpi_evaluate_object(adev->handle, "CLDB", NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ obj = buffer.pointer;
+ if (!obj) {
+ dev_err(&adev->dev, "ACPI device has no CLDB object\n");
+ return -ENODEV;
+ }
+
+ if (obj->type != ACPI_TYPE_BUFFER) {
+ dev_err(&adev->dev, "CLDB object is not an ACPI buffer\n");
+ ret = -EINVAL;
+ goto out_free_buff;
+ }
+
+ if (obj->buffer.length > sizeof(cldb)) {
+ dev_err(&adev->dev, "The CLDB buffer is too large\n");
+ ret = -EINVAL;
+ goto out_free_buff;
+ }
+
+ memcpy(&cldb, obj->buffer.pointer, obj->buffer.length);
+
+ /*
+ * control_logic_type = 1 indicates this is a dummy INT3472 device of
+ * the kind we're looking for. If any other value then we shouldn't try
+ * to handle it
+ */
+ if (cldb.control_logic_type != 1) {
+ ret = -EINVAL;
+ goto out_free_buff;
+ }
+
+ /* Space for 4 GPIOs - one more than we've seen so far plus a null */
+ int3472 = kzalloc(sizeof(*int3472) +
+ ((INT3472_MAX_SENSOR_GPIOS + 1) * sizeof(struct gpiod_lookup)),
+ GFP_KERNEL);
+ if (!int3472) {
+ ret = -ENOMEM;
+ goto out_free_buff;
+ }
+
+ int3472->adev = adev;
+ adev->driver_data = int3472;
+
+ int3472->sensor = acpi_dev_get_next_dep_dev(adev, NULL);
+ if (!int3472->sensor) {
+ dev_err(&adev->dev,
+ "This INT3472 entry seems to have no dependents.\n");
+ ret = -ENODEV;
+ goto out_free_int3472;
+ }
+
+ int3472->gpios.dev_id = i2c_acpi_dev_name(int3472->sensor);
+
+ INIT_LIST_HEAD(&int3472->regulators);
+
+ int3472_parse_crs(int3472);
+
+ goto out_free_buff;
+
+out_free_int3472:
+ kfree(int3472);
+out_free_buff:
+ kfree(buffer.pointer);
+ return ret;
+}
+
+static int int3472_remove(struct acpi_device *adev)
+{
+ struct int3472_gpio_regulator *reg;
+ struct int3472_device *int3472;
+
+ int3472 = acpi_driver_data(adev);
+
+ acpi_dev_put(int3472->sensor);
+ gpiod_remove_lookup_table(&int3472->gpios);
+
+ list_for_each_entry(reg, &int3472->regulators, list) {
+ gpiod_put(reg->gpio);
+ regulator_unregister(reg->rdev);
+ }
+
+ kfree(int3472);
+
+ return 0;
+}
+
+static const struct acpi_device_id int3472_device_id[] = {
+ { "INT3472", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, int3472_device_id);
+
+static struct acpi_driver int3472_driver = {
+ .name = "int3472",
+ .ids = int3472_device_id,
+ .ops = {
+ .add = int3472_add,
+ .remove = int3472_remove,
+ },
+ .owner = THIS_MODULE,
+};
+
+module_acpi_driver(int3472_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Dan Scally <djrscally@xxxxxxxxx>");
+MODULE_DESCRIPTION("ACPI Driver for Discrete type INT3472 ACPI Devices");
diff --git a/drivers/media/pci/intel/ipu3/int3472.h b/drivers/media/pci/intel/ipu3/int3472.h
new file mode 100644
index 000000000000..6964726e8e1f
--- /dev/null
+++ b/drivers/media/pci/intel/ipu3/int3472.h
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Author: Dan Scally <djrscally@xxxxxxxxx> */
+#include <linux/regulator/machine.h>
+
+#define INT3472_MAX_SENSOR_GPIOS 3
+#define GPIO_REGULATOR_NAME_LENGTH 17
+#define GPIO_REGULATOR_SUPPLY_NAME_LENGTH 9
+
+#define INT3472_REGULATOR(_NAME, _SUPPLY, _ID, _OPS) \
+ ((const struct regulator_desc) { \
+ .name = _NAME, \
+ .supply_name = _SUPPLY, \
+ .id = _ID, \
+ .type = REGULATOR_VOLTAGE, \
+ .ops = _OPS, \
+ .owner = THIS_MODULE, \
+ })
+
+const guid_t int3472_gpio_guid = GUID_INIT(0x79234640, 0x9e10, 0x4fea,
+ 0xa5, 0xc1, 0xb5, 0xaa, 0x8b,
+ 0x19, 0x75, 0x6f);
+
+const guid_t cio2_sensor_module_guid = GUID_INIT(0x822ace8f, 0x2814, 0x4174,
+ 0xa5, 0x6b, 0x5f, 0x02, 0x9f,
+ 0xe0, 0x79, 0xee);
+
+struct int3472_cldb {
+ u8 version;
+ /*
+ * control logic type
+ * 0: UNKNOWN
+ * 1: DISCRETE(CRD-D)
+ * 2: PMIC TPS68470
+ * 3: PMIC uP6641
+ */
+ u8 control_logic_type;
+ u8 control_logic_id;
+ u8 sensor_card_sku;
+ u8 reserved[28];
+};
+
+struct int3472_device {
+ struct acpi_device *adev;
+ struct acpi_device *sensor;
+
+ unsigned int n_gpios; /* how many GPIOs have we seen */
+
+ unsigned int n_regulators;
+ struct list_head regulators;
+
+ unsigned int n_sensor_gpios; /* how many have we mapped to sensor */
+ struct gpiod_lookup_table gpios;
+};
+
+struct int3472_gpio_regulator {
+ char regulator_name[GPIO_REGULATOR_NAME_LENGTH];
+ char supply_name[GPIO_REGULATOR_SUPPLY_NAME_LENGTH];
+ struct gpio_desc *gpio;
+ struct regulator_dev *rdev;
+ struct regulator_desc rdesc;
+ struct list_head list;
+};
+
+struct int3472_sensor_regulator_map {
+ char *sensor_module_name;
+ unsigned int n_supplies;
+ struct regulator_consumer_supply *supplies;
+};
+
+/*
+ * Here follows platform specific mapping information that we can pass to
+ * regulator_init_data when we register our regulators. They're just mapped
+ * via index, I.E. the first regulator pin that the code finds for the
+ * i2c-OVTI2680:00 device is avdd, the second is dovdd and so on.
+ */
+
+static struct regulator_consumer_supply miix_510_ov2680[] = {
+ { "i2c-OVTI2680:00", "avdd" },
+ { "i2c-OVTI2680:00", "dovdd" },
+};
+
+static struct regulator_consumer_supply surface_go2_ov5693[] = {
+ { "i2c-INT33BE:00", "avdd" },
+ { "i2c-INT33BE:00", "dovdd" },
+};
+
+static struct regulator_consumer_supply surface_book_ov5693[] = {
+ { "i2c-INT33BE:00", "avdd" },
+ { "i2c-INT33BE:00", "dovdd" },
+};
+
+static struct int3472_sensor_regulator_map int3472_sensor_regulator_maps[] = {
+ { "GNDF140809R", 2, miix_510_ov2680 },
+ { "YHCU", 2, surface_go2_ov5693 },
+ { "MSHW0070", 2, surface_book_ov5693 },
+};
--
2.25.1
