1 files changed, 352 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/int3472/clk_and_regulator.c b/drivers/platform/x86/intel/int3472/clk_and_regulator.c
new file mode 100644
index 0000000000..ef4b3141ef
--- /dev/null
+++ b/drivers/platform/x86/intel/int3472/clk_and_regulator.c
@@ -0,0 +1,352 @@
+// 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/dmi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/driver.h>
+#include <linux/slab.h>
+
+#include "common.h"
+
+/*
+ * 82c0d13a-78c5-4244-9bb1-eb8b539a8d11
+ * This _DSM GUID allows controlling the sensor clk when it is not controlled
+ * through a GPIO.
+ */
+static const guid_t img_clk_guid =
+	GUID_INIT(0x82c0d13a, 0x78c5, 0x4244,
+		  0x9b, 0xb1, 0xeb, 0x8b, 0x53, 0x9a, 0x8d, 0x11);
+
+static void skl_int3472_enable_clk(struct int3472_clock *clk, int enable)
+{
+	struct int3472_discrete_device *int3472 = to_int3472_device(clk);
+	union acpi_object args[3];
+	union acpi_object argv4;
+
+	if (clk->ena_gpio) {
+		gpiod_set_value_cansleep(clk->ena_gpio, enable);
+		return;
+	}
+
+	args[0].integer.type = ACPI_TYPE_INTEGER;
+	args[0].integer.value = clk->imgclk_index;
+	args[1].integer.type = ACPI_TYPE_INTEGER;
+	args[1].integer.value = enable;
+	args[2].integer.type = ACPI_TYPE_INTEGER;
+	args[2].integer.value = 1;
+
+	argv4.type = ACPI_TYPE_PACKAGE;
+	argv4.package.count = 3;
+	argv4.package.elements = args;
+
+	acpi_evaluate_dsm(acpi_device_handle(int3472->adev), &img_clk_guid,
+			  0, 1, &argv4);
+}
+
+/*
+ * 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;
+
+static int skl_int3472_clk_prepare(struct clk_hw *hw)
+{
+	skl_int3472_enable_clk(to_int3472_clk(hw), 1);
+	return 0;
+}
+
+static void skl_int3472_clk_unprepare(struct clk_hw *hw)
+{
+	skl_int3472_enable_clk(to_int3472_clk(hw), 0);
+}
+
+static int skl_int3472_clk_enable(struct clk_hw *hw)
+{
+	/*
+	 * We're just turning a GPIO on to enable the clock, which operation
+	 * has the potential to sleep. Given .enable() cannot sleep, but
+	 * .prepare() can, we toggle the GPIO in .prepare() instead. Thus,
+	 * nothing to do here.
+	 */
+	return 0;
+}
+
+static void skl_int3472_clk_disable(struct clk_hw *hw)
+{
+	/* Likewise, nothing to do here... */
+}
+
+static unsigned int skl_int3472_get_clk_frequency(struct int3472_discrete_device *int3472)
+{
+	union acpi_object *obj;
+	unsigned int freq;
+
+	obj = skl_int3472_get_acpi_buffer(int3472->sensor, "SSDB");
+	if (IS_ERR(obj))
+		return 0; /* report rate as 0 on error */
+
+	if (obj->buffer.length < CIO2_SENSOR_SSDB_MCLKSPEED_OFFSET + sizeof(u32)) {
+		dev_err(int3472->dev, "The buffer is too small\n");
+		kfree(obj);
+		return 0;
+	}
+
+	freq = *(u32 *)(obj->buffer.pointer + CIO2_SENSOR_SSDB_MCLKSPEED_OFFSET);
+
+	kfree(obj);
+	return freq;
+}
+
+static unsigned long skl_int3472_clk_recalc_rate(struct clk_hw *hw,
+						 unsigned long parent_rate)
+{
+	struct int3472_clock *clk = to_int3472_clk(hw);
+
+	return clk->frequency;
+}
+
+static const struct clk_ops skl_int3472_clock_ops = {
+	.prepare = skl_int3472_clk_prepare,
+	.unprepare = skl_int3472_clk_unprepare,
+	.enable = skl_int3472_clk_enable,
+	.disable = skl_int3472_clk_disable,
+	.recalc_rate = skl_int3472_clk_recalc_rate,
+};
+
+int skl_int3472_register_dsm_clock(struct int3472_discrete_device *int3472)
+{
+	struct acpi_device *adev = int3472->adev;
+	struct clk_init_data init = {
+		.ops = &skl_int3472_clock_ops,
+		.flags = CLK_GET_RATE_NOCACHE,
+	};
+	int ret;
+
+	if (int3472->clock.cl)
+		return 0; /* A GPIO controlled clk has already been registered */
+
+	if (!acpi_check_dsm(adev->handle, &img_clk_guid, 0, BIT(1)))
+		return 0; /* DSM clock control is not available */
+
+	init.name = kasprintf(GFP_KERNEL, "%s-clk", acpi_dev_name(adev));
+	if (!init.name)
+		return -ENOMEM;
+
+	int3472->clock.frequency = skl_int3472_get_clk_frequency(int3472);
+	int3472->clock.clk_hw.init = &init;
+	int3472->clock.clk = clk_register(&adev->dev, &int3472->clock.clk_hw);
+	if (IS_ERR(int3472->clock.clk)) {
+		ret = PTR_ERR(int3472->clock.clk);
+		goto out_free_init_name;
+	}
+
+	int3472->clock.cl = clkdev_create(int3472->clock.clk, NULL, int3472->sensor_name);
+	if (!int3472->clock.cl) {
+		ret = -ENOMEM;
+		goto err_unregister_clk;
+	}
+
+	kfree(init.name);
+	return 0;
+
+err_unregister_clk:
+	clk_unregister(int3472->clock.clk);
+out_free_init_name:
+	kfree(init.name);
+	return ret;
+}
+
+int skl_int3472_register_gpio_clock(struct int3472_discrete_device *int3472,
+				    struct acpi_resource_gpio *agpio, u32 polarity)
+{
+	char *path = agpio->resource_source.string_ptr;
+	struct clk_init_data init = {
+		.ops = &skl_int3472_clock_ops,
+		.flags = CLK_GET_RATE_NOCACHE,
+	};
+	int ret;
+
+	if (int3472->clock.cl)
+		return -EBUSY;
+
+	int3472->clock.ena_gpio = acpi_get_and_request_gpiod(path, agpio->pin_table[0],
+							     "int3472,clk-enable");
+	if (IS_ERR(int3472->clock.ena_gpio)) {
+		ret = PTR_ERR(int3472->clock.ena_gpio);
+		int3472->clock.ena_gpio = NULL;
+		return dev_err_probe(int3472->dev, ret, "getting clk-enable GPIO\n");
+	}
+
+	if (polarity == GPIO_ACTIVE_LOW)
+		gpiod_toggle_active_low(int3472->clock.ena_gpio);
+
+	/* Ensure the pin is in output mode and non-active state */
+	gpiod_direction_output(int3472->clock.ena_gpio, 0);
+
+	init.name = kasprintf(GFP_KERNEL, "%s-clk",
+			      acpi_dev_name(int3472->adev));
+	if (!init.name) {
+		ret = -ENOMEM;
+		goto out_put_gpio;
+	}
+
+	int3472->clock.frequency = skl_int3472_get_clk_frequency(int3472);
+
+	int3472->clock.clk_hw.init = &init;
+	int3472->clock.clk = clk_register(&int3472->adev->dev,
+					  &int3472->clock.clk_hw);
+	if (IS_ERR(int3472->clock.clk)) {
+		ret = PTR_ERR(int3472->clock.clk);
+		goto out_free_init_name;
+	}
+
+	int3472->clock.cl = clkdev_create(int3472->clock.clk, NULL,
+					  int3472->sensor_name);
+	if (!int3472->clock.cl) {
+		ret = -ENOMEM;
+		goto err_unregister_clk;
+	}
+
+	kfree(init.name);
+	return 0;
+
+err_unregister_clk:
+	clk_unregister(int3472->clock.clk);
+out_free_init_name:
+	kfree(init.name);
+out_put_gpio:
+	gpiod_put(int3472->clock.ena_gpio);
+
+	return ret;
+}
+
+void skl_int3472_unregister_clock(struct int3472_discrete_device *int3472)
+{
+	if (!int3472->clock.cl)
+		return;
+
+	clkdev_drop(int3472->clock.cl);
+	clk_unregister(int3472->clock.clk);
+	gpiod_put(int3472->clock.ena_gpio);
+}
+
+/*
+ * The INT3472 device is going to be the only supplier of a regulator for
+ * the sensor device. But unlike the clk framework the regulator framework
+ * does not allow matching by consumer-device-name only.
+ *
+ * Ideally all sensor drivers would use "avdd" as supply-id. But for drivers
+ * where this cannot be changed because another supply-id is already used in
+ * e.g. DeviceTree files an alias for the other supply-id can be added here.
+ *
+ * Do not forget to update GPIO_REGULATOR_SUPPLY_MAP_COUNT when changing this.
+ */
+static const char * const skl_int3472_regulator_map_supplies[] = {
+	"avdd",
+	"AVDD",
+};
+
+static_assert(ARRAY_SIZE(skl_int3472_regulator_map_supplies) ==
+	      GPIO_REGULATOR_SUPPLY_MAP_COUNT);
+
+/*
+ * On some models there is a single GPIO regulator which is shared between
+ * sensors and only listed in the ACPI resources of one sensor.
+ * This DMI table contains the name of the second sensor. This is used to add
+ * entries for the second sensor to the supply_map.
+ */
+static const struct dmi_system_id skl_int3472_regulator_second_sensor[] = {
+	{
+		/* Lenovo Miix 510-12IKB */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "MIIX 510-12IKB"),
+		},
+		.driver_data = "i2c-OVTI2680:00",
+	},
+	{ }
+};
+
+int skl_int3472_register_regulator(struct int3472_discrete_device *int3472,
+				   struct acpi_resource_gpio *agpio)
+{
+	char *path = agpio->resource_source.string_ptr;
+	struct regulator_init_data init_data = { };
+	struct regulator_config cfg = { };
+	const char *second_sensor = NULL;
+	const struct dmi_system_id *id;
+	int i, j, ret;
+
+	id = dmi_first_match(skl_int3472_regulator_second_sensor);
+	if (id)
+		second_sensor = id->driver_data;
+
+	for (i = 0, j = 0; i < ARRAY_SIZE(skl_int3472_regulator_map_supplies); i++) {
+		int3472->regulator.supply_map[j].supply = skl_int3472_regulator_map_supplies[i];
+		int3472->regulator.supply_map[j].dev_name = int3472->sensor_name;
+		j++;
+
+		if (second_sensor) {
+			int3472->regulator.supply_map[j].supply =
+				skl_int3472_regulator_map_supplies[i];
+			int3472->regulator.supply_map[j].dev_name = second_sensor;
+			j++;
+		}
+	}
+
+	init_data.constraints.valid_ops_mask = REGULATOR_CHANGE_STATUS;
+	init_data.consumer_supplies = int3472->regulator.supply_map;
+	init_data.num_consumer_supplies = j;
+
+	snprintf(int3472->regulator.regulator_name,
+		 sizeof(int3472->regulator.regulator_name), "%s-regulator",
+		 acpi_dev_name(int3472->adev));
+	snprintf(int3472->regulator.supply_name,
+		 GPIO_REGULATOR_SUPPLY_NAME_LENGTH, "supply-0");
+
+	int3472->regulator.rdesc = INT3472_REGULATOR(
+						int3472->regulator.regulator_name,
+						int3472->regulator.supply_name,
+						&int3472_gpio_regulator_ops);
+
+	int3472->regulator.gpio = acpi_get_and_request_gpiod(path, agpio->pin_table[0],
+							     "int3472,regulator");
+	if (IS_ERR(int3472->regulator.gpio)) {
+		ret = PTR_ERR(int3472->regulator.gpio);
+		int3472->regulator.gpio = NULL;
+		return dev_err_probe(int3472->dev, ret, "getting regulator GPIO\n");
+	}
+
+	/* Ensure the pin is in output mode and non-active state */
+	gpiod_direction_output(int3472->regulator.gpio, 0);
+
+	cfg.dev = &int3472->adev->dev;
+	cfg.init_data = &init_data;
+	cfg.ena_gpiod = int3472->regulator.gpio;
+
+	int3472->regulator.rdev = regulator_register(int3472->dev,
+						     &int3472->regulator.rdesc,
+						     &cfg);
+	if (IS_ERR(int3472->regulator.rdev)) {
+		ret = PTR_ERR(int3472->regulator.rdev);
+		goto err_free_gpio;
+	}
+
+	return 0;
+
+err_free_gpio:
+	gpiod_put(int3472->regulator.gpio);
+
+	return ret;
+}
+
+void skl_int3472_unregister_regulator(struct int3472_discrete_device *int3472)
+{
+	regulator_unregister(int3472->regulator.rdev);
+	gpiod_put(int3472->regulator.gpio);
+}