[2/3] mfd: intel_soc_pmic: Rename pwm_backlight pwm-lookup to pwm_pmic_backlight
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Message ID 20191119151818.67531-3-hdegoede@redhat.com
State New
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Series
  • drm/i915 / LPSS / mfd: Select correct PWM controller to use based on VBT
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Commit Message

Hans de Goede Nov. 19, 2019, 3:18 p.m. UTC
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 Crystal Cove PMIC's PWM
controller to "pwm_pmic_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>
---
 drivers/mfd/intel_soc_pmic_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Lee Jones Dec. 10, 2019, 8:51 a.m. UTC | #1
On Tue, 19 Nov 2019, 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 Crystal Cove PMIC's PWM
> controller to "pwm_pmic_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>
> ---
>  drivers/mfd/intel_soc_pmic_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

For my own reference:
  Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
Hans de Goede Dec. 11, 2019, 5:29 p.m. UTC | #2
Hi Lee,

On 10-12-2019 09:51, Lee Jones wrote:
> On Tue, 19 Nov 2019, 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 Crystal Cove PMIC's PWM
>> controller to "pwm_pmic_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>
>> ---
>>   drivers/mfd/intel_soc_pmic_core.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> For my own reference:
>    Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>

As mentioned in the cover-letter, to avoid breaking bi-sectability
as well as to avoid breaking the intel-gfx CI we need to merge this series
in one go through one tree. Specifically through the drm-intel tree.
Is that ok with you ?

If this is ok with you, then you do not have to do anything, I will just push
the entire series to drm-intel. drivers/mfd/intel_soc_pmic_core.c
does not see much changes so I do not expect this to lead to any conflicts.

Regards,

Hans

Patch
diff mbox series

diff --git a/drivers/mfd/intel_soc_pmic_core.c b/drivers/mfd/intel_soc_pmic_core.c
index c9f35378d391..47188df3080d 100644
--- a/drivers/mfd/intel_soc_pmic_core.c
+++ b/drivers/mfd/intel_soc_pmic_core.c
@@ -38,7 +38,7 @@  static struct gpiod_lookup_table panel_gpio_table = {
 
 /* PWM consumed by the Intel GFX */
 static struct pwm_lookup crc_pwm_lookup[] = {
-	PWM_LOOKUP("crystal_cove_pwm", 0, "0000:00:02.0", "pwm_backlight", 0, PWM_POLARITY_NORMAL),
+	PWM_LOOKUP("crystal_cove_pwm", 0, "0000:00:02.0", "pwm_pmic_backlight", 0, PWM_POLARITY_NORMAL),
 };
 
 static int intel_soc_pmic_i2c_probe(struct i2c_client *i2c,