Message ID | 20180413125417.7263-1-hdegoede@redhat.com |
---|---|
State | Not Applicable |
Headers | show |
Series | ACPI / LPSS: Only call pwm_add_table() for Bay Trail PWM if PMIC HRV is 2 | expand |
On Fri, 2018-04-13 at 14:54 +0200, Hans de Goede wrote: > The Point of View mobii wintab p800w Bay Trail tablet comes with a > Crystal > Cove PMIC, yet uses the LPSS PWM for backlight control, rather then > the > Crystal Cove's PWM, so we need to call pwm_add_table() to add a > pwm_backlight mapping for the LPSS pwm despite there being an INT33FD > ACPI device present. > > On all Bay Trail devices the _HRV object of the INT33FD ACPI device > will normally return 2, to indicate the Bay Trail variant of the CRC > PMIC is present, except on this tablet where _HRV is 0xffff. I guess > this > is a hack to make the windows Crystal Cove PWM driver not bind. > > Out of the 44 DSTDs with an INT33FD device in there which I have (from > different model devices) only the pov mobii wintab p800w uses 0xffff > for > the HRV. > > The byt_pwm_setup code calls acpi_dev_present to check for the > presence > of a INT33FD ACPI device which indicates that a CRC PMIC is present > and > if the INT33FD ACPI device is present then byt_pwm_setup will not add > a pwm_backlight mapping for the LPSS pwm, so that the CRC PWM will get > used instead. > > acpi_dev_present has a hrv parameter, this commit make us pass 2 > instead > of -1, so that things still match on normal tablets, but on this > special > case with its _HRV of 0xffff, the check will now fail so that the > pwm_backlight mapping for the LPSS pwm gets added fixing backlight > brightness control on this device. > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > drivers/acpi/acpi_lpss.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c > index c4ba9164e582..38a286975c31 100644 > --- a/drivers/acpi/acpi_lpss.c > +++ b/drivers/acpi/acpi_lpss.c > @@ -69,6 +69,10 @@ 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 { > @@ -162,7 +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, -1)) > + if (!acpi_dev_present("INT33FD", NULL, BYT_CRC_HRV)) > pwm_add_table(byt_pwm_lookup, > ARRAY_SIZE(byt_pwm_lookup)); > } >
On Friday, April 20, 2018 3:31:30 PM CEST Andy Shevchenko wrote: > On Fri, 2018-04-13 at 14:54 +0200, Hans de Goede wrote: > > The Point of View mobii wintab p800w Bay Trail tablet comes with a > > Crystal > > Cove PMIC, yet uses the LPSS PWM for backlight control, rather then > > the > > Crystal Cove's PWM, so we need to call pwm_add_table() to add a > > pwm_backlight mapping for the LPSS pwm despite there being an INT33FD > > ACPI device present. > > > > On all Bay Trail devices the _HRV object of the INT33FD ACPI device > > will normally return 2, to indicate the Bay Trail variant of the CRC > > PMIC is present, except on this tablet where _HRV is 0xffff. I guess > > this > > is a hack to make the windows Crystal Cove PWM driver not bind. > > > > Out of the 44 DSTDs with an INT33FD device in there which I have (from > > different model devices) only the pov mobii wintab p800w uses 0xffff > > for > > the HRV. > > > > The byt_pwm_setup code calls acpi_dev_present to check for the > > presence > > of a INT33FD ACPI device which indicates that a CRC PMIC is present > > and > > if the INT33FD ACPI device is present then byt_pwm_setup will not add > > a pwm_backlight mapping for the LPSS pwm, so that the CRC PWM will get > > used instead. > > > > acpi_dev_present has a hrv parameter, this commit make us pass 2 > > instead > > of -1, so that things still match on normal tablets, but on this > > special > > case with its _HRV of 0xffff, the check will now fail so that the > > pwm_backlight mapping for the LPSS pwm gets added fixing backlight > > brightness control on this device. > > > > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Applied, thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index c4ba9164e582..38a286975c31 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -69,6 +69,10 @@ 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 { @@ -162,7 +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, -1)) + if (!acpi_dev_present("INT33FD", NULL, BYT_CRC_HRV)) pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup)); }
The Point of View mobii wintab p800w Bay Trail tablet comes with a Crystal Cove PMIC, yet uses the LPSS PWM for backlight control, rather then the Crystal Cove's PWM, so we need to call pwm_add_table() to add a pwm_backlight mapping for the LPSS pwm despite there being an INT33FD ACPI device present. On all Bay Trail devices the _HRV object of the INT33FD ACPI device will normally return 2, to indicate the Bay Trail variant of the CRC PMIC is present, except on this tablet where _HRV is 0xffff. I guess this is a hack to make the windows Crystal Cove PWM driver not bind. Out of the 44 DSTDs with an INT33FD device in there which I have (from different model devices) only the pov mobii wintab p800w uses 0xffff for the HRV. The byt_pwm_setup code calls acpi_dev_present to check for the presence of a INT33FD ACPI device which indicates that a CRC PMIC is present and if the INT33FD ACPI device is present then byt_pwm_setup will not add a pwm_backlight mapping for the LPSS pwm, so that the CRC PWM will get used instead. acpi_dev_present has a hrv parameter, this commit make us pass 2 instead of -1, so that things still match on normal tablets, but on this special case with its _HRV of 0xffff, the check will now fail so that the pwm_backlight mapping for the LPSS pwm gets added fixing backlight brightness control on this device. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/acpi/acpi_lpss.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)