Re: [PATCH v6 2/5] platform/x86: int3472: tps68470: fix clock consumer registration for Dell Latitude 5285

Sakari Ailus
2026-04-27T07:48:31Z

Hi Thierry,

Thanks for the update.

One question regarding the set: is
Documentation/process/coding-assistants.rst relevant for this?

On Sat, Apr 25, 2026 at 09:31:42AM -0700, Thierry Chatard wrote:
> The BIOS on the Dell Latitude 5285 leaves GNVS field C0TP at zero.
> With C0TP=0 the ACPI _DEP method on INT3479 (OV5670, front camera)
> resolves to PCI0 instead of the INT3472 (TPS68470 PMIC) device.
>
> Because for_each_acpi_consumer_dev() walks the _DEP reverse-mapping,
> INT3479 is invisible to it: the clock consumer lookup entry for the
> front camera is never registered with the tps68470-clk driver, and
> the OV5670 sensor driver cannot acquire its MCLK.
>
> Fix this without touching ACPI tables by adding optional static clock
> consumer fields to struct int3472_tps68470_board_data:
>
> unsigned int n_clk_consumers;
> const struct tps68470_clk_consumer *clk_consumers;
>
> When board data is present and n_clk_consumers is non-zero, probe uses
> the static list instead of for_each_acpi_consumer_dev() to populate
> tps68470-clk platform data. Platforms that do not set these fields
> continue to use the existing ACPI traversal path unchanged.
>
> The board_data lookup is moved before the clock-pdata allocation so
> that it is available for both the static and dynamic paths.
>
> Signed-off-by: Thierry Chatard <tchatard@gmail.com>
> ---
> drivers/platform/x86/intel/int3472/tps68470.c | 113 +++++++++++-------
> drivers/platform/x86/intel/int3472/tps68470.h | 10 ++
> 2 files changed, 79 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/platform/x86/intel/int3472/tps68470.c b/drivers/platform/x86/intel/int3472/tps68470.c
> index a496075c0..92da2ba80 100644
> --- a/drivers/platform/x86/intel/int3472/tps68470.c
> +++ b/drivers/platform/x86/intel/int3472/tps68470.c
> @@ -147,17 +147,41 @@ static int skl_int3472_tps68470_probe(struct i2c_client *client)
> struct tps68470_clk_platform_data *clk_pdata;
> struct mfd_cell *cells;
> struct regmap *regmap;
> + struct gpiod_lookup_table * const *tables;
> int n_consumers;
> int device_type;
> int ret;
> - int i;
> + unsigned int i;
>
> if (!adev)
> return -ENODEV;
>
> - n_consumers = skl_int3472_fill_clk_pdata(&client->dev, &clk_pdata);
> - if (n_consumers < 0)
> - return n_consumers;
> + /*
> + * Look up board data before building clock platform data. On
> + * platforms where a sensor's ACPI _DEP does not list the INT3472
> + * device, for_each_acpi_consumer_dev() misses that sensor and its
> + * clock consumer entry is never registered. Board data can supply
> + * a static consumer list to use instead, bypassing the broken _DEP
> + * traversal.
> + */
> + board_data = int3472_tps68470_get_board_data(dev_name(&client->dev));
> +
> + if (board_data && board_data->n_clk_consumers) {
> + clk_pdata = devm_kzalloc(&client->dev,
> + struct_size(clk_pdata, consumers,
> + board_data->n_clk_consumers),
> + GFP_KERNEL);
> + if (!clk_pdata)
> + return -ENOMEM;
> + clk_pdata->n_consumers = board_data->n_clk_consumers;
> + for (i = 0; i < board_data->n_clk_consumers; i++)
> + clk_pdata->consumers[i] = board_data->clk_consumers[i];
> + n_consumers = board_data->n_clk_consumers;
> + } else {
> + n_consumers = skl_int3472_fill_clk_pdata(&client->dev, &clk_pdata);
> + if (n_consumers < 0)
> + return n_consumers;
> + }

board_data is only relevant for the Windows case and is tested after the
switch anyway. Please move this chunk after the switch.

>
> regmap = devm_regmap_init_i2c(client, &tps68470_regmap_config);
> if (IS_ERR(regmap)) {
> @@ -176,52 +200,53 @@ static int skl_int3472_tps68470_probe(struct i2c_client *client)
> device_type = skl_int3472_tps68470_calc_type(adev);
> switch (device_type) {
> case DESIGNED_FOR_WINDOWS:
> - board_data = int3472_tps68470_get_board_data(dev_name(&client->dev));
> - if (!board_data)
> - return dev_err_probe(&client->dev, -ENODEV, "No board-data found for this model\n");
> -
> - cells = kzalloc_objs(*cells, TPS68470_WIN_MFD_CELL_COUNT);
> - if (!cells)
> - return -ENOMEM;
> -
> - /*
> - * The order of the cells matters here! The clk must be first
> - * because the regulator depends on it. The gpios must be last,
> - * acpi_gpiochip_add() calls acpi_dev_clear_dependencies() and
> - * the clk + regulators must be ready when this happens.
> - */
> - cells[0].name = "tps68470-clk";
> - cells[0].platform_data = clk_pdata;
> - cells[0].pdata_size = struct_size(clk_pdata, consumers, n_consumers);
> - cells[1].name = "tps68470-regulator";
> - cells[1].platform_data = (void *)board_data->tps68470_regulator_pdata;
> - cells[1].pdata_size = sizeof(struct tps68470_regulator_platform_data);
> - cells[2].name = "tps68470-gpio";
> -
> - for (i = 0; i < board_data->n_gpiod_lookups; i++)
> - gpiod_add_lookup_table(board_data->tps68470_gpio_lookup_tables[i]);
> -
> - ret = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_NONE,
> - cells, TPS68470_WIN_MFD_CELL_COUNT,
> - NULL, 0, NULL);
> - kfree(cells);
> -
> - if (ret) {
> - for (i = 0; i < board_data->n_gpiod_lookups; i++)
> - gpiod_remove_lookup_table(board_data->tps68470_gpio_lookup_tables[i]);
> - }
> -
> break;
> case DESIGNED_FOR_CHROMEOS:
> - ret = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_NONE,
> - tps68470_cros, ARRAY_SIZE(tps68470_cros),
> - NULL, 0, NULL);
> - break;
> + return devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_NONE,
> + tps68470_cros,
> + ARRAY_SIZE(tps68470_cros),
> + NULL, 0, NULL);
> default:
> dev_err(&client->dev, "Failed to add MFD devices\n");
> return device_type;
> }
>
> + if (!board_data)
> + return dev_err_probe(&client->dev, -ENODEV,
> + "No board-data found for this model\n");
> +
> + cells = kzalloc_objs(*cells, TPS68470_WIN_MFD_CELL_COUNT);
> + if (!cells)
> + return -ENOMEM;
> +
> + /*
> + * The order of the cells matters here! The clk must be first
> + * because the regulator depends on it. The gpios must be last,
> + * acpi_gpiochip_add() calls acpi_dev_clear_dependencies() and
> + * the clk + regulators must be ready when this happens.
> + */
> + cells[0].name = "tps68470-clk";
> + cells[0].platform_data = clk_pdata;
> + cells[0].pdata_size = struct_size(clk_pdata, consumers, n_consumers);
> + cells[1].name = "tps68470-regulator";
> + cells[1].platform_data = (void *)board_data->tps68470_regulator_pdata;
> + cells[1].pdata_size = sizeof(struct tps68470_regulator_platform_data);
> + cells[2].name = "tps68470-gpio";
> +
> + tables = board_data->tps68470_gpio_lookup_tables;
> + for (i = 0; i < board_data->n_gpiod_lookups; i++)
> + gpiod_add_lookup_table(tables[i]);
> +
> + ret = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_NONE,
> + cells, TPS68470_WIN_MFD_CELL_COUNT,
> + NULL, 0, NULL);
> + kfree(cells);
> +
> + if (ret) {
> + for (i = 0; i < board_data->n_gpiod_lookups; i++)
> + gpiod_remove_lookup_table(tables[i]);
> + }
> +
> /*
> * No acpi_dev_clear_dependencies() here, since the acpi_gpiochip_add()
> * for the GPIO cell already does this.
> @@ -233,7 +258,7 @@ static int skl_int3472_tps68470_probe(struct i2c_client *client)
> static void skl_int3472_tps68470_remove(struct i2c_client *client)
> {
> const struct int3472_tps68470_board_data *board_data;
> - int i;
> + unsigned int i;
>
> board_data = int3472_tps68470_get_board_data(dev_name(&client->dev));
> if (board_data) {
> diff --git a/drivers/platform/x86/intel/int3472/tps68470.h b/drivers/platform/x86/intel/int3472/tps68470.h
> index 35915e701..1d3d67459 100644
> --- a/drivers/platform/x86/intel/int3472/tps68470.h
> +++ b/drivers/platform/x86/intel/int3472/tps68470.h
> @@ -12,11 +12,21 @@
> #define _INTEL_SKL_INT3472_TPS68470_H
>
> struct gpiod_lookup_table;
> +struct tps68470_clk_consumer;
> struct tps68470_regulator_platform_data;
>
> struct int3472_tps68470_board_data {
> const char *dev_name;
> const struct tps68470_regulator_platform_data *tps68470_regulator_pdata;
> + /*
> + * Static clock consumers. When n_clk_consumers is non-zero these
> + * are used in place of for_each_acpi_consumer_dev() to build the
> + * tps68470-clk platform data. Needed on platforms where a sensor's
> + * ACPI _DEP does not list the INT3472 device, causing that sensor
> + * to be missed by the ACPI dependency traversal.
> + */
> + unsigned int n_clk_consumers;
> + const struct tps68470_clk_consumer *clk_consumers;
> unsigned int n_gpiod_lookups;
> struct gpiod_lookup_table *tps68470_gpio_lookup_tables[];
> };

--
Regards,

Sakari Ailus