Re: [PATCH 1/3] ACPI / LPSS: Rename pwm_backlight pwm-lookup to pwm_soc_backlight

Rafael J. Wysocki
2019-11-29T11:59:44Z

On Tuesday, November 19, 2019 4:18:16 PM CET Hans de Goede wrote:
> At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2
> different PWM controllers for controlling the LCD's backlight brightness.
> Either the one integrated into the PMIC or the one integrated into the
> SoC (the 1st LPSS PWM controller).
>
> So far in the LPSS code on BYT we have skipped registering the LPSS PWM
> controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is
> present, assuming that in this case the PMIC PWM controller will be used.
>
> On CHT we have been relying on only 1 of the 2 PWM controllers being
> enabled in the DSDT at the same time; and always registered the lookup.
>
> So far this has been working, but the correct way to determine which PWM
> controller needs to be used is by checking a bit in the VBT table and
> recently I've learned about 2 different BYT devices:
> Point of View MOBII TAB-P800W
> Acer Switch 10 SW5-012
>
> Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS
> PWM controller (and the VBT correctly indicates this), so here our old
> heuristics fail.
>
> Since only the i915 driver has access to the VBT, this commit renames
> the "pwm_backlight" lookup entries for the 1st BYT/CHT LPSS PWM controller
> to "pwm_soc_backlight" so that the i915 driver can do a pwm_get() for
> the right controller depending on the VBT bit, instead of the i915 driver
> relying on a "pwm_backlight" lookup getting registered which magically
> points to the right controller.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Or please let me know if you want me to take the whole series.

Thanks!

> ---
> drivers/acpi/acpi_lpss.c | 11 +++--------
> 1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
> index 751ed38f2a10..63e81d8e675b 100644
> --- a/drivers/acpi/acpi_lpss.c
> +++ b/drivers/acpi/acpi_lpss.c
> @@ -69,10 +69,6 @@ ACPI_MODULE_NAME("acpi_lpss");
> #define LPSS_SAVE_CTX BIT(4)
> #define LPSS_NO_D3_DELAY BIT(5)
>
> -/* Crystal Cove PMIC shares same ACPI ID between different platforms */
> -#define BYT_CRC_HRV 2
> -#define CHT_CRC_HRV 3
> -
> struct lpss_private_data;
>
> struct lpss_device_desc {
> @@ -158,7 +154,7 @@ static void lpss_deassert_reset(struct lpss_private_data *pdata)
> */
> static struct pwm_lookup byt_pwm_lookup[] = {
> PWM_LOOKUP_WITH_MODULE("80860F09:00", 0, "0000:00:02.0",
> - "pwm_backlight", 0, PWM_POLARITY_NORMAL,
> + "pwm_soc_backlight", 0, PWM_POLARITY_NORMAL,
> "pwm-lpss-platform"),
> };
>
> @@ -170,8 +166,7 @@ static void byt_pwm_setup(struct lpss_private_data *pdata)
> if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
> return;
>
> - if (!acpi_dev_present("INT33FD", NULL, BYT_CRC_HRV))
> - pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
> + pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
> }
>
> #define LPSS_I2C_ENABLE 0x6c
> @@ -204,7 +199,7 @@ static void byt_i2c_setup(struct lpss_private_data *pdata)
> /* BSW PWM used for backlight control by the i915 driver */
> static struct pwm_lookup bsw_pwm_lookup[] = {
> PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
> - "pwm_backlight", 0, PWM_POLARITY_NORMAL,
> + "pwm_soc_backlight", 0, PWM_POLARITY_NORMAL,
> "pwm-lpss-platform"),
> };
>
>