MODULE_DESCRIPTION("Ancillary routines for binding ACPI devices");
MODULE_LICENSE("GPL");
-
-/*
- * The below helper functions don't really belong here and should eventually be
- * moved to some place under drivers/media/v4l2-core.
- */
-#include <linux/platform_data/x86/soc.h>
-
-/*
- * 79234640-9e10-4fea-a5c1-b5aa8b19756f
- * This _DSM GUID returns information about the GPIO lines mapped to a sensor.
- * Function number 1 returns a count of the GPIO lines that are mapped.
- * Subsequent functions return 32 bit ints encoding information about the GPIO.
- */
-static const guid_t intel_sensor_gpio_info_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 intel_sensor_module_guid =
- GUID_INIT(0x822ace8f, 0x2814, 0x4174,
- 0xa5, 0x6b, 0x5f, 0x02, 0x9f, 0xe0, 0x79, 0xee);
-
-#define INTEL_DSM_TYPE_SHIFT 0
-#define INTEL_DSM_TYPE_MASK GENMASK(7, 0)
-#define INTEL_DSM_PIN_SHIFT 8
-#define INTEL_DSM_PIN_MASK GENMASK(15, 8)
-#define INTEL_DSM_SENSOR_ON_VAL_SHIFT 24
-#define INTEL_DSM_SENSOR_ON_VAL_MASK GENMASK(31, 24)
-
-#define INTEL_DSM_TYPE(x) \
- (((x) & INTEL_DSM_TYPE_MASK) >> INTEL_DSM_TYPE_SHIFT)
-#define INTEL_DSM_PIN(x) \
- (((x) & INTEL_DSM_PIN_MASK) >> INTEL_DSM_PIN_SHIFT)
-#define INTEL_DSM_SENSOR_ON_VAL(x) \
- (((x) & INTEL_DSM_SENSOR_ON_VAL_MASK) >> INTEL_DSM_SENSOR_ON_VAL_SHIFT)
-
-#define V4L2_SENSOR_MAX_ACPI_GPIOS 2u
-
-struct v4l2_acpi_gpio_map {
- struct acpi_gpio_params params[V4L2_SENSOR_MAX_ACPI_GPIOS];
- struct acpi_gpio_mapping mapping[V4L2_SENSOR_MAX_ACPI_GPIOS + 1];
-};
-
-struct v4l2_acpi_gpio_parsing_data {
- struct device *dev;
- u32 settings[V4L2_SENSOR_MAX_ACPI_GPIOS];
- unsigned int settings_count;
- unsigned int res_count;
- unsigned int map_count;
- struct v4l2_acpi_gpio_map *map;
-};
-
-/* Note this always returns 1 to continue looping so that res_count is accurate */
-static int v4l2_acpi_handle_gpio_res(struct acpi_resource *ares, void *_data)
-{
- struct v4l2_acpi_gpio_parsing_data *data = _data;
- struct acpi_resource_gpio *agpio;
- const char *name;
- bool active_low;
- unsigned int i;
- u32 settings = 0;
- u8 pin;
-
- if (!acpi_gpio_get_io_resource(ares, &agpio))
- return 1; /* Not a GPIO, continue the loop */
-
- data->res_count++;
-
- pin = agpio->pin_table[0];
- for (i = 0; i < data->settings_count; i++) {
- if (INTEL_DSM_PIN(data->settings[i]) == pin) {
- settings = data->settings[i];
- break;
- }
- }
-
- if (i == data->settings_count) {
- dev_warn(data->dev, "Could not find DSM GPIO settings for pin %d\n", pin);
- return 1;
- }
-
- switch (INTEL_DSM_TYPE(settings)) {
- case 0:
- name = "reset-gpios";
- break;
- case 1:
- name = "powerdown-gpios";
- break;
- default:
- dev_warn(data->dev, "Unknown GPIO type 0x%02lx for pin %d\n",
- INTEL_DSM_TYPE(settings), pin);
- return 1;
- }
-
- /*
- * Both reset and power-down need to be logical false when the sensor
- * is on (sensor should not be in reset and not be powered-down). So
- * when the sensor-on-value (which is the physical pin value) is high,
- * then the signal is active-low.
- */
- active_low = INTEL_DSM_SENSOR_ON_VAL(settings) ? true : false;
-
- i = data->map_count;
- if (i == V4L2_SENSOR_MAX_ACPI_GPIOS)
- return 1;
-
- /* res_count is already incremented */
- data->map->params[i].crs_entry_index = data->res_count - 1;
- data->map->params[i].active_low = active_low;
- data->map->mapping[i].name = name;
- data->map->mapping[i].data = &data->map->params[i];
- data->map->mapping[i].size = 1;
- data->map_count++;
-
- dev_info(data->dev, "%s crs %d %s pin %d active-%s\n", name,
- data->res_count - 1, agpio->resource_source.string_ptr,
- pin, active_low ? "low" : "high");
-
- return 1;
-}
-
-/*
- * Helper function to create an ACPI GPIO lookup table for sensor reset and
- * powerdown signals on Intel Bay Trail (BYT) and Cherry Trail (CHT) devices,
- * including setting the correct polarity for the GPIO.
- *
- * This uses the "79234640-9e10-4fea-a5c1-b5aa8b19756f" DSM method directly
- * on the sensor device's ACPI node. This is different from later Intel
- * hardware which has a separate INT3472 with this info. Since there is
- * no separate firmware-node to which we can bind to register the GPIO lookups
- * this unfortunately means that all sensor drivers which may be used on
- * BYT or CHT hw need to call this function. This also means that this function
- * may only fail when it is actually called on BYT/CHT hw. In all other cases
- * it must always succeed.
- *
- * Note this code uses the same DSM GUID as the INT3472 discrete.c code
- * and there is some overlap, but there are enough differences that it is
- * difficult to share the code.
- */
-int v4l2_get_acpi_sensor_info(struct device *dev, char **module_id_str)
-{
- struct acpi_device *adev = ACPI_COMPANION(dev);
- struct v4l2_acpi_gpio_parsing_data data = { };
- LIST_HEAD(resource_list);
- union acpi_object *obj;
- unsigned int i, j;
- int ret;
-
- if (module_id_str)
- *module_id_str = NULL;
-
- if (!adev)
- return 0;
-
- obj = acpi_evaluate_dsm_typed(adev->handle, &intel_sensor_module_guid,
- 0x00, 0x01, NULL, ACPI_TYPE_STRING);
- if (obj) {
- dev_info(dev, "Sensor module id: '%s'\n", obj->string.pointer);
- if (module_id_str)
- *module_id_str = kstrdup(obj->string.pointer, GFP_KERNEL);
-
- ACPI_FREE(obj);
- }
-
- if (!soc_intel_is_byt() && !soc_intel_is_cht())
- return 0;
-
- /*
- * First get the GPIO-settings count and then get count GPIO-settings
- * values. Note the order of these may differ from the order in which
- * the GPIOs are listed on the ACPI resources! So we first store them all
- * and then enumerate the ACPI resources and match them up by pin number.
- */
- obj = acpi_evaluate_dsm_typed(adev->handle,
- &intel_sensor_gpio_info_guid, 0x00, 1,
- NULL, ACPI_TYPE_INTEGER);
- if (!obj)
- return dev_err_probe(dev, -EIO, "No _DSM entry for GPIO pin count\n");
-
- data.settings_count = obj->integer.value;
- ACPI_FREE(obj);
-
- if (data.settings_count > V4L2_SENSOR_MAX_ACPI_GPIOS)
- return dev_err_probe(dev, -EIO, "Too many GPIOs %u > %u\n",
- data.settings_count, V4L2_SENSOR_MAX_ACPI_GPIOS);
-
- for (i = 0; i < data.settings_count; i++) {
- /*
- * i + 2 because the index of this _DSM function is 1-based
- * and the first function is just a count.
- */
- obj = acpi_evaluate_dsm_typed(adev->handle,
- &intel_sensor_gpio_info_guid,
- 0x00, i + 2,
- NULL, ACPI_TYPE_INTEGER);
- if (!obj)
- return dev_err_probe(dev, -EIO, "No _DSM entry for GPIO pin %u\n", i);
-
- data.settings[i] = obj->integer.value;
- ACPI_FREE(obj);
- }
-
- /* Since we match up by pin-number the pin-numbers must be unique */
- for (i = 0; i < data.settings_count; i++) {
- for (j = i + 1; j < data.settings_count; j++) {
- if (INTEL_DSM_PIN(data.settings[i]) !=
- INTEL_DSM_PIN(data.settings[j]))
- continue;
-
- return dev_err_probe(dev, -EIO, "Duplicate pin number %lu\n",
- INTEL_DSM_PIN(data.settings[i]));
- }
- }
-
- /* Use devm_kzalloc() for the mappings + params to auto-free them */
- data.map = devm_kzalloc(dev, sizeof(*data.map), GFP_KERNEL);
- if (!data.map)
- return -ENOMEM;
-
- /* Now parse the ACPI resources and build the lookup table */
- data.dev = dev;
- ret = acpi_dev_get_resources(adev, &resource_list,
- v4l2_acpi_handle_gpio_res, &data);
- if (ret < 0)
- return ret;
-
- acpi_dev_free_resource_list(&resource_list);
-
- if (data.map_count != data.settings_count ||
- data.res_count != data.settings_count)
- dev_warn(dev, "ACPI GPIO resources vs DSM GPIO-info count mismatch (dsm: %d res: %d map %d\n",
- data.settings_count, data.res_count, data.map_count);
-
- return devm_acpi_dev_add_driver_gpios(dev, data.map->mapping);
-}
-EXPORT_SYMBOL_GPL(v4l2_get_acpi_sensor_info);
projects / platform / kernel / linux-starfive.git / commitdiff