On Sat, Apr 1, 2023 at 4:59 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> ACPI nodes describing sensors on atomisp devices implement a
> "79234640-9e10-4fea-a5c1-b5aa8b19756f" Device Specific Method (DSM)
> to get info about the GPIOs.
>
> Using this method is necessary to figure out which ACPI GPIO resource
> is "reset" and which one is "powerdown" and this is also necessary to
> figure out the correct polarity of the pins.
>
> One example where this is necessary is the GC0310 sensor. The current
> GC0310 code hardcodes reset as being active-low and power-down as being
> active-high. This works on a number of devices such as the mpman
> converter 9. But it is wrong for the Chuwi Vi8 CWI501 where the powerdown
> pin is active-low.
>
> Rather then adding DMI quirks for this, add a helper for this,
> which can be shared between sensor-drivers. This new helper optionally
> also returns a string identifying the exact sensor-module used, which
> might be useful if any module specific behvior is necessary in the sensor
> driver.
>
> This uses the DSM directly on the sensor device's ACPI node. This is
> different from later Intel hardware (IPU3 / IPU6) which has a separate
> INT3472 node (with its own driver) with this info.
>
> Since there is no separate ACPI node to which we can bind to register GPIO
> lookups, this unfortunately means that all sensor drivers which may be used
> on BYT or CHT hw need to call this new helper.
>
> Note for now this function is being added to atomisp_gmin_platform.c,
> but once things are ready to move atomisp over to using generic sensor
> drivers this will need to become a generic v4l2 sensor helper. but this
> will require upstream discussion first.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> .../atomisp/include/linux/atomisp_platform.h | 2 +
> .../media/atomisp/pci/atomisp_gmin_platform.c | 240 ++++++++++++++++++
> 2 files changed, 242 insertions(+)
>
> diff --git a/drivers/staging/media/atomisp/include/linux/atomisp_platform.h b/drivers/staging/media/atomisp/include/linux/atomisp_platform.h
> index b77bf814a5a6..e8e965f73fc8 100644
> --- a/drivers/staging/media/atomisp/include/linux/atomisp_platform.h
> +++ b/drivers/staging/media/atomisp/include/linux/atomisp_platform.h
> @@ -213,6 +213,8 @@ int atomisp_register_sensor_no_gmin(struct v4l2_subdev *subdev, u32 lanes,
> enum atomisp_bayer_order bayer_order);
> void atomisp_unregister_subdev(struct v4l2_subdev *subdev);
>
> +int v4l2_get_acpi_sensor_info(struct device *dev, char **module_id_str);
> +
> /* API from old platform_camera.h, new CPUID implementation */
> #define __IS_SOC(x) (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && \
> boot_cpu_data.x86 == 6 && \
> diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
> index 7fc7dfa56172..f8d8a34d7e7f 100644
> --- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
> +++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
> @@ -1447,3 +1447,243 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0f38, isp_pm_cap_fixup);
>
> 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 sys/drivers/media/v4l2-core .
Redundant sys/ and space at the end.
> + */
> +#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;
> + 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
), so
> + * when the sensor-on-value, which is the physical pin value is high,
The sub sentence between commas is a bit unreadable.
> + * then the signal is active-low.
> + */
> + active_low = INTEL_DSM_SENSOR_ON_VAL(settings) ? true : false;
Redundant '? true : false" part.
> + 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;
So, you (might) call the previous _DSM for any SoC, is it intentional?
> + /*
> + * 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);
> --
> 2.39.1
>
--
With Best Regards,
Andy Shevchenko
