On 03/13/2015 10:50 PM, Daniel Vetter wrote:
> On Fri, Mar 13, 2015 at 04:30:43PM +0200, Ville Syrjälä wrote:
>> On Thu, Mar 12, 2015 at 10:01:33PM +0530, Shobhit Kumar wrote:
>>> CC: Samuel Ortiz <sa...@linux.intel.com>
>>> Cc: Linus Walleij <linus.wall...@linaro.org>
>>> Cc: Alexandre Courbot <gnu...@gmail.com>
>>> Cc: Thierry Reding <thierry.red...@gmail.com>
>>> Signed-off-by: Shobhit Kumar <shobhit.ku...@intel.com>
>>> ---
>>> drivers/gpu/drm/i915/intel_dsi.c | 25 +++++++++++++++++++++++++
>>> drivers/gpu/drm/i915/intel_dsi.h | 3 +++
>>> 2 files changed, 28 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_dsi.c
>>> b/drivers/gpu/drm/i915/intel_dsi.c
>>> index 219421c..511446f 100644
>>> --- a/drivers/gpu/drm/i915/intel_dsi.c
>>> +++ b/drivers/gpu/drm/i915/intel_dsi.c
>>> @@ -32,6 +32,7 @@
>>> #include <drm/drm_mipi_dsi.h>
>>> #include <linux/slab.h>
>>> #include <linux/gpio/consumer.h>
>>> +#include <linux/pwm.h>
>>> #include "i915_drv.h"
>>> #include "intel_drv.h"
>>> #include "intel_dsi.h"
>>> @@ -402,6 +403,10 @@ static void intel_dsi_enable(struct intel_encoder
>>> *encoder)
>>>
>>> intel_dsi_port_enable(encoder);
>>> }
>>> +
>>> + /* Enable the backlight with default PWM as programmed by BIOS */
>>> + pwm_enable(intel_dsi->pwm);
>>> + pwm_config_alternate(intel_dsi->pwm, 0x7F, 100);
>>
>> I suppose we migth want to wrap these in 'if (intel_dsi->pwm)' checks,
>> or does the pwm subsystem take care of NULL checks for us?
>>
>>> }
>>>
>>> static void intel_dsi_pre_enable(struct intel_encoder *encoder)
>>> @@ -467,6 +472,11 @@ static void intel_dsi_pre_disable(struct intel_encoder
>>> *encoder)
>>>
>>> DRM_DEBUG_KMS("\n");
>>>
>>> + /* Disable the backlight */
>>> + pwm_config_alternate(intel_dsi->pwm, 0x7F, 0);
>>> + usleep_range(2000, 3000);
>>> + pwm_disable(intel_dsi->pwm);
>>
>> ditto
>>
>>> +
>>> if (is_vid_mode(intel_dsi)) {
>>> /* Send Shutdown command to the panel in LP mode */
>>> for_each_dsi_port(port, intel_dsi->ports)
>>> @@ -971,6 +981,10 @@ static void intel_dsi_encoder_destroy(struct
>>> drm_encoder *encoder)
>>> if (intel_dsi->gpio_panel)
>>> gpiod_put(intel_dsi->gpio_panel);
>>>
>>> + /* dispose of the pwm */
>>> + if (intel_dsi->pwm)
>>> + pwm_put(intel_dsi->pwm);
>>> +
>>> intel_encoder_destroy(encoder);
>>> }
>>>
>>> @@ -1098,6 +1112,17 @@ void intel_dsi_init(struct drm_device *dev)
>>> DRM_ERROR("Failed to own gpio for panel control\n");
>>> intel_dsi->gpio_panel = NULL;
>>> }
>>> +
>>> + /* Get the PWM chip for backlight control */
>>> + intel_dsi->pwm = pwm_get(dev->dev, "pwm_backlight");
>>> + if (IS_ERR(intel_dsi->pwm)) {
>>> + DRM_ERROR("Faild to own the pwm chip\n");
>>> + intel_dsi->pwm = NULL;
>
> If the i915.ko driver loads before the mfd.ko driver we need to do a
> deferred probe here I think. Just failing isn't robust.
The PMIC MFD driver is a boolean if you remember our discussions earlier
and hence I made the PWM driver also a bool config. Given that i915 is a
.ko in default kernel config, perhaps it should not be that big an issue
for now. But I will look into deferred probe as a fail safe.
>
> This also means that if people don't configure their kernel properly then
> we'll fall over here, but meh.
True.
Regards
Shobhit
> -Daniel
>
>>> + } else if (pwm_config_alternate(intel_dsi->pwm, 0x7F, 100) < 0)
>>> {
>>> + DRM_ERROR("Failed to configure the pwm chip\n");
>>> + pwm_put(intel_dsi->pwm);
>>> + intel_dsi->pwm = NULL;
>>> + }
>>> }
>>>
>>> intel_encoder->type = INTEL_OUTPUT_DSI;
>>> diff --git a/drivers/gpu/drm/i915/intel_dsi.h
>>> b/drivers/gpu/drm/i915/intel_dsi.h
>>> index 8be75a7..d8ec9c1 100644
>>> --- a/drivers/gpu/drm/i915/intel_dsi.h
>>> +++ b/drivers/gpu/drm/i915/intel_dsi.h
>>> @@ -52,6 +52,9 @@ struct intel_dsi {
>>> /* GPIO Desc for CRC based Panel control */
>>> struct gpio_desc *gpio_panel;
>>>
>>> + /* PWM chip */
>>> + struct pwm_device *pwm;
>>> +
>>> struct intel_connector *attached_connector;
>>>
>>> /* bit mask of ports being driven */
>>> --
>>> 2.1.0
>>>
>>> _______________________________________________
>>> Intel-gfx mailing list
>>> Intel-gfx@lists.freedesktop.org
>>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>>
>> --
>> Ville Syrjälä
>> Intel OTC
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
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