1 files changed, 417 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c b/drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c
new file mode 100644
index 000000000000..8c18dbff1c43
--- /dev/null
+++ b/drivers/platform/x86/intel-int3472/intel_skl_int3472_discrete.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Author: Dan Scally <djrscally@gmail.com> */
+
+#include <linux/acpi.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/machine.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/platform_device.h>
+#include <linux/uuid.h>
+
+#include "intel_skl_int3472_common.h"
+
+/*
+ * 79234640-9e10-4fea-a5c1-b5aa8b19756f
+ * This _DSM GUID returns information about the GPIO lines mapped to a
+ * discrete INT3472 device. Function number 1 returns a count of the GPIO
+ * lines that are mapped. Subsequent functions return 32 bit ints encoding
+ * information about the GPIO line, including its purpose.
+ */
+static const guid_t int3472_gpio_guid =
+	GUID_INIT(0x79234640, 0x9e10, 0x4fea,
+		  0xa5, 0xc1, 0xb5, 0xaa, 0x8b, 0x19, 0x75, 0x6f);
+
+/*
+ * 822ace8f-2814-4174-a56b-5f029fe079ee
+ * This _DSM GUID returns a string from the sensor device, which acts as a
+ * module identifier.
+ */
+static const guid_t cio2_sensor_module_guid =
+	GUID_INIT(0x822ace8f, 0x2814, 0x4174,
+		  0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
+
+/*
+ * Here follows platform specific mapping information that we can pass to
+ * the functions mapping resources to the sensors. Where the sensors have
+ * a power enable pin defined in DSDT we need to provide a supply name so
+ * the sensor drivers can find the regulator. The device name will be derived
+ * from the sensor's ACPI device within the code. Optionally, we can provide a
+ * NULL terminated array of function name mappings to deal with any platform
+ * specific deviations from the documented behaviour of GPIOs.
+ *
+ * Map a GPIO function name to NULL to prevent the driver from mapping that
+ * GPIO at all.
+ */
+
+static const struct int3472_gpio_function_remap ov2680_gpio_function_remaps[] = {
+	{ "reset", NULL },
+	{ "powerdown", "reset" },
+	{ }
+};
+
+static const struct int3472_sensor_config int3472_sensor_configs[] = {
+	/* Lenovo Miix 510-12ISK - OV2680, Front */
+	{ "GNDF140809R", { 0 }, ov2680_gpio_function_remaps },
+	/* Lenovo Miix 510-12ISK - OV5648, Rear */
+	{ "GEFF150023R", REGULATOR_SUPPLY("avdd", NULL), NULL },
+	/* Surface Go 1&2 - OV5693, Front */
+	{ "YHCU", REGULATOR_SUPPLY("avdd", NULL), NULL },
+};
+
+static const struct int3472_sensor_config *
+skl_int3472_get_sensor_module_config(struct int3472_discrete_device *int3472)
+{
+	union acpi_object *obj;
+	unsigned int i;
+
+	obj = acpi_evaluate_dsm_typed(int3472->sensor->handle,
+				      &cio2_sensor_module_guid, 0x00,
+				      0x01, NULL, ACPI_TYPE_STRING);
+
+	if (!obj) {
+		dev_err(int3472->dev,
+			"Failed to get sensor module string from _DSM\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	if (obj->string.type != ACPI_TYPE_STRING) {
+		dev_err(int3472->dev,
+			"Sensor _DSM returned a non-string value\n");
+
+		ACPI_FREE(obj);
+		return ERR_PTR(-EINVAL);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(int3472_sensor_configs); i++) {
+		if (!strcmp(int3472_sensor_configs[i].sensor_module_name,
+			    obj->string.pointer))
+			break;
+	}
+
+	ACPI_FREE(obj);
+
+	if (i >= ARRAY_SIZE(int3472_sensor_configs))
+		return ERR_PTR(-EINVAL);
+
+	return &int3472_sensor_configs[i];
+}
+
+static int skl_int3472_map_gpio_to_sensor(struct int3472_discrete_device *int3472,
+					  struct acpi_resource *ares,
+					  const char *func, u32 polarity)
+{
+	char *path = ares->data.gpio.resource_source.string_ptr;
+	const struct int3472_sensor_config *sensor_config;
+	struct gpiod_lookup *table_entry;
+	struct acpi_device *adev;
+	acpi_handle handle;
+	acpi_status status;
+	int ret;
+
+	if (int3472->n_sensor_gpios >= INT3472_MAX_SENSOR_GPIOS) {
+		dev_warn(int3472->dev, "Too many GPIOs mapped\n");
+		return -EINVAL;
+	}
+
+	sensor_config = int3472->sensor_config;
+	if (!IS_ERR(sensor_config) && sensor_config->function_maps) {
+		const struct int3472_gpio_function_remap *remap;
+
+		for (remap = sensor_config->function_maps; remap->documented; remap++) {
+			if (!strcmp(func, remap->documented)) {
+				func = remap->actual;
+				break;
+			}
+		}
+	}
+
+	/* Functions mapped to NULL should not be mapped to the sensor */
+	if (!func)
+		return 0;
+
+	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 = &int3472->gpios.table[int3472->n_sensor_gpios];
+	table_entry->key = acpi_dev_name(adev);
+	table_entry->chip_hwnum = ares->data.gpio.pin_table[0];
+	table_entry->con_id = func;
+	table_entry->idx = 0;
+	table_entry->flags = polarity;
+
+	int3472->n_sensor_gpios++;
+
+	return 0;
+}
+
+static int skl_int3472_map_gpio_to_clk(struct int3472_discrete_device *int3472,
+				       struct acpi_resource *ares, u8 type)
+{
+	char *path = ares->data.gpio.resource_source.string_ptr;
+	struct gpio_desc *gpio;
+
+	switch (type) {
+	case INT3472_GPIO_TYPE_CLK_ENABLE:
+		gpio = acpi_get_and_request_gpiod(path, ares->data.gpio.pin_table[0],
+						  "int3472,clk-enable");
+		if (IS_ERR(gpio))
+			return (PTR_ERR(gpio));
+
+		int3472->clock.ena_gpio = gpio;
+		break;
+	case INT3472_GPIO_TYPE_PRIVACY_LED:
+		gpio = acpi_get_and_request_gpiod(path, ares->data.gpio.pin_table[0],
+						  "int3472,privacy-led");
+		if (IS_ERR(gpio))
+			return (PTR_ERR(gpio));
+
+		int3472->clock.led_gpio = gpio;
+		break;
+	default:
+		dev_err(int3472->dev, "Invalid GPIO type 0x%02x for clock\n", type);
+		break;
+	}
+
+	return 0;
+}
+
+/**
+ * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
+ * @ares: A pointer to a &struct acpi_resource
+ * @data: A pointer to a &struct int3472_discrete_device
+ *
+ * This function handles GPIO resources that are against an INT3472
+ * ACPI device, by checking the value of the corresponding _DSM entry.
+ * This will return a 32bit int, where the lowest byte represents the
+ * function of the GPIO pin:
+ *
+ * 0x00 Reset
+ * 0x01 Power down
+ * 0x0b Power enable
+ * 0x0c Clock enable
+ * 0x0d Privacy LED
+ *
+ * There are some known platform specific quirks where that does not quite
+ * hold up; for example where a pin with type 0x01 (Power down) is mapped to
+ * a sensor pin that performs a reset function or entries in _CRS and _DSM that
+ * do not actually correspond to a physical connection. These will be handled
+ * by the mapping sub-functions.
+ *
+ * GPIOs will either be mapped directly to the sensor device or else used
+ * to create clocks and regulators via the usual frameworks.
+ *
+ * Return:
+ * * 1		- To continue the loop
+ * * 0		- When all resources found are handled properly.
+ * * -EINVAL	- If the resource is not a GPIO IO resource
+ * * -ENODEV	- If the resource has no corresponding _DSM entry
+ * * -Other	- Errors propagated from one of the sub-functions.
+ */
+static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
+					     void *data)
+{
+	struct int3472_discrete_device *int3472 = data;
+	struct acpi_resource_gpio *agpio;
+	union acpi_object *obj;
+	const char *err_msg;
+	int ret;
+	u8 type;
+
+	if (!acpi_gpio_get_io_resource(ares, &agpio))
+		return 1;
+
+	/*
+	 * ngpios + 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->ngpios + 2,
+				      NULL, ACPI_TYPE_INTEGER);
+
+	if (!obj) {
+		dev_warn(int3472->dev, "No _DSM entry for GPIO pin %u\n",
+			 ares->data.gpio.pin_table[0]);
+		return 1;
+	}
+
+	type = obj->integer.value & 0xff;
+
+	switch (type) {
+	case INT3472_GPIO_TYPE_RESET:
+		ret = skl_int3472_map_gpio_to_sensor(int3472, ares, "reset",
+						     GPIO_ACTIVE_LOW);
+		if (ret)
+			err_msg = "Failed to map reset pin to sensor\n";
+
+		break;
+	case INT3472_GPIO_TYPE_POWERDOWN:
+		ret = skl_int3472_map_gpio_to_sensor(int3472, ares,
+						     "powerdown",
+						     GPIO_ACTIVE_LOW);
+		if (ret)
+			err_msg = "Failed to map powerdown pin to sensor\n";
+
+		break;
+	case INT3472_GPIO_TYPE_CLK_ENABLE:
+	case INT3472_GPIO_TYPE_PRIVACY_LED:
+		ret = skl_int3472_map_gpio_to_clk(int3472, ares, type);
+		if (ret)
+			err_msg = "Failed to map GPIO to clock\n";
+
+		break;
+	case INT3472_GPIO_TYPE_POWER_ENABLE:
+		ret = skl_int3472_register_regulator(int3472, ares);
+		if (ret)
+			err_msg = "Failed to map regulator to sensor\n";
+
+		break;
+	default:
+		dev_warn(int3472->dev,
+			 "GPIO type 0x%02x unknown; the sensor may not work\n",
+			 type);
+		ret = 1;
+		break;
+	}
+
+	int3472->ngpios++;
+	ACPI_FREE(obj);
+
+	if (ret)
+		return dev_err_probe(int3472->dev, ret, err_msg);
+
+	return 0;
+}
+
+static int skl_int3472_parse_crs(struct int3472_discrete_device *int3472)
+{
+	LIST_HEAD(resource_list);
+	int ret;
+
+	/*
+	 * No error check, because not having a sensor config is not necessarily
+	 * a failure mode.
+	 */
+	int3472->sensor_config = skl_int3472_get_sensor_module_config(int3472);
+
+	ret = acpi_dev_get_resources(int3472->adev, &resource_list,
+				     skl_int3472_handle_gpio_resources,
+				     int3472);
+	if (ret)
+		goto out_free_res_list;
+
+	/*
+	 * If we find no clock enable GPIO pin then the privacy LED won't work.
+	 * We've never seen that situation, but it's possible. Warn the user so
+	 * it's clear what's happened.
+	 */
+	if (int3472->clock.ena_gpio) {
+		ret = skl_int3472_register_clock(int3472);
+		if (ret)
+			goto out_free_res_list;
+	} else {
+		if (int3472->clock.led_gpio)
+			dev_warn(int3472->dev,
+				 "No clk GPIO. The privacy LED won't work\n");
+	}
+
+	int3472->gpios.dev_id = int3472->sensor_name;
+	gpiod_add_lookup_table(&int3472->gpios);
+
+out_free_res_list:
+	acpi_dev_free_resource_list(&resource_list);
+
+	return ret;
+}
+
+int skl_int3472_discrete_probe(struct platform_device *pdev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	struct int3472_discrete_device *int3472;
+	struct int3472_cldb cldb;
+	int ret;
+
+	ret = skl_int3472_fill_cldb(adev, &cldb);
+	if (ret) {
+		dev_err(&pdev->dev, "Couldn't fill CLDB structure\n");
+		return ret;
+	}
+
+	if (cldb.control_logic_type != 1) {
+		dev_err(&pdev->dev, "Unsupported control logic type %u\n",
+			cldb.control_logic_type);
+		return -EINVAL;
+	}
+
+	/* Max num GPIOs we've seen plus a terminator */
+	int3472 = devm_kzalloc(&pdev->dev, struct_size(int3472, gpios.table,
+			       INT3472_MAX_SENSOR_GPIOS + 1), GFP_KERNEL);
+	if (!int3472)
+		return -ENOMEM;
+
+	int3472->adev = adev;
+	int3472->dev = &pdev->dev;
+	platform_set_drvdata(pdev, int3472);
+
+	int3472->sensor = acpi_dev_get_first_consumer_dev(adev);
+	if (!int3472->sensor) {
+		dev_err(&pdev->dev, "INT3472 seems to have no dependents.\n");
+		return -ENODEV;
+	}
+
+	int3472->sensor_name = devm_kasprintf(int3472->dev, GFP_KERNEL,
+					      I2C_DEV_NAME_FORMAT,
+					      acpi_dev_name(int3472->sensor));
+	if (!int3472->sensor_name) {
+		ret = -ENOMEM;
+		goto err_put_sensor;
+	}
+
+	/*
+	 * Initialising this list means we can call gpiod_remove_lookup_table()
+	 * in failure paths without issue.
+	 */
+	INIT_LIST_HEAD(&int3472->gpios.list);
+
+	ret = skl_int3472_parse_crs(int3472);
+	if (ret) {
+		skl_int3472_discrete_remove(pdev);
+		return ret;
+	}
+
+	return 0;
+
+err_put_sensor:
+	acpi_dev_put(int3472->sensor);
+
+	return ret;
+}
+
+int skl_int3472_discrete_remove(struct platform_device *pdev)
+{
+	struct int3472_discrete_device *int3472 = platform_get_drvdata(pdev);
+
+	gpiod_remove_lookup_table(&int3472->gpios);
+	regulator_unregister(int3472->regulator.rdev);
+	clk_unregister(int3472->clock.clk);
+
+	if (int3472->clock.cl)
+		clkdev_drop(int3472->clock.cl);
+
+	gpiod_put(int3472->regulator.gpio);
+	gpiod_put(int3472->clock.ena_gpio);
+	gpiod_put(int3472->clock.led_gpio);
+
+	return 0;
+}