[Intel-gfx] [PATCH 4/6] drm/i915/cnp: Backlight support for CNP.

Srivatsa, Anusha anusha.srivatsa at intel.com
Tue May 9 00:11:42 UTC 2017



>-----Original Message-----
>From: Pandiyan, Dhinakaran
>Sent: Monday, May 8, 2017 5:10 PM
>To: Srivatsa, Anusha <anusha.srivatsa at intel.com>
>Cc: intel-gfx at lists.freedesktop.org; Vivi, Rodrigo <rodrigo.vivi at intel.com>;
>Nikula, Jani <jani.nikula at intel.com>
>Subject: Re: [Intel-gfx] [PATCH 4/6] drm/i915/cnp: Backlight support for CNP.
>
>On Mon, 2017-05-08 at 16:45 -0700, Anusha Srivatsa wrote:
>> From: Rodrigo Vivi <rodrigo.vivi at intel.com>
>>
>> Split out BXT and CNP's setup_backlight(),enable_backlight(),
>> disable_backlight() and hz_to_pwm() into two separate functions
>> instead of reusing BXT function.
>>
>> Reuse set_backlight() and get_backlight() since they have no reference
>> to the utility pin.
>>
>> v2: Reuse BXT functions with controller 0 instead of
>>     redefining it. (Jani).
>>     Use dev_priv->rawclk_freq instead of getting the value
>>     from SFUSE_STRAP.
>> v3: Avoid setup backligh controller along with hooks and
>>     fully reuse hooks setup as suggested by Jani.
>> v4: Clean up commit message.
>> v5: Implement per PCH instead per platform.
>>
>> v6: Introduce a new function for CNP.(Jani and Ville)
>>
>> v7: Squash the all CNP Backlight support patches into a single patch.
>> (Jani)
>>
>> v8: Correct indentation, remove unneeded blank lines and correct mail
>> address (Jani).
>>
>> Reviewed-by: Jani Nikula <jani.nikula at intel.com>
>> Suggested-by: Jani Nikula <jani.nikula at intel.com>
>> Suggested-by: Ville Syrjala <ville.syrjala at intel.com>
>> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
>> Cc: Jani Nikula <jani.nikula at intel.com>
>> Signed-off-by: Anusha Srivatsa <anusha.srivatsa at intel.com>
>> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_panel.c | 94
>> ++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 94 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_panel.c
>> b/drivers/gpu/drm/i915/intel_panel.c
>> index cb50c52..22da1e2 100644
>> --- a/drivers/gpu/drm/i915/intel_panel.c
>> +++ b/drivers/gpu/drm/i915/intel_panel.c
>> @@ -796,6 +796,19 @@ static void bxt_disable_backlight(struct
>intel_connector *connector)
>>  	}
>>  }
>>
>> +static void cnp_disable_backlight(struct intel_connector *connector)
>> +{
>> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> +	struct intel_panel *panel = &connector->panel;
>> +	u32 tmp;
>> +
>> +	intel_panel_actually_set_backlight(connector, 0);
>> +
>> +	tmp = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
>> +	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
>> +		   tmp & ~BXT_BLC_PWM_ENABLE);
>> +}
>> +
>>  static void pwm_disable_backlight(struct intel_connector *connector)
>> {
>>  	struct intel_panel *panel = &connector->panel; @@ -1076,6 +1089,36
>> @@ static void bxt_enable_backlight(struct intel_connector *connector)
>>  			pwm_ctl | BXT_BLC_PWM_ENABLE);
>>  }
>>
>> +static void cnp_enable_backlight(struct intel_connector *connector) {
>> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> +	struct intel_panel *panel = &connector->panel;
>> +	enum pipe pipe = intel_get_pipe_from_connector(connector);
>> +	u32 pwm_ctl;
>> +
>> +	pwm_ctl = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
>> +	if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
>> +		DRM_DEBUG_KMS("backlight already enabled\n");
>> +		pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
>> +		I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
>> +			   pwm_ctl);
>> +	}
>> +
>> +	I915_WRITE(BXT_BLC_PWM_FREQ(panel->backlight.controller),
>> +		   panel->backlight.max);
>> +
>> +	intel_panel_actually_set_backlight(connector,
>> +panel->backlight.level);
>> +
>> +	pwm_ctl = 0;
>> +	if (panel->backlight.active_low_pwm)
>> +		pwm_ctl |= BXT_BLC_PWM_POLARITY;
>> +
>> +	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller), pwm_ctl);
>> +	POSTING_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
>> +	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
>> +		   pwm_ctl | BXT_BLC_PWM_ENABLE);
>> +}
>> +
>>  static void pwm_enable_backlight(struct intel_connector *connector)
>> {
>>  	struct intel_panel *panel = &connector->panel; @@ -1239,6 +1282,18
>> @@ void intel_backlight_device_unregister(struct intel_connector
>> *connector)  #endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */
>>
>>  /*
>> + * CNP: PWM clock frequency is 19.2 MHz or 24 MHz.
>> + *      Value is found in SFUSE_STRAP.
>> + *      PWM increment = 1
>> + */
>> +static u32 cnp_hz_to_pwm(struct intel_connector *connector, u32
>> +pwm_freq_hz) {
>> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> +
>> +	return DIV_ROUND_CLOSEST(KHz(dev_priv->rawclk_freq),
>pwm_freq_hz); }
>> +
>> +/*
>>   * BXT: PWM clock frequency = 19.2 MHz.
>>   */
>>  static u32 bxt_hz_to_pwm(struct intel_connector *connector, u32
>> pwm_freq_hz) @@ -1633,6 +1688,37 @@ bxt_setup_backlight(struct
>intel_connector *connector, enum pipe unused)
>>  	return 0;
>>  }
>>
>> +static int
>> +cnp_setup_backlight(struct intel_connector *connector, enum pipe
>> +unused) {
>> +	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
>> +	struct intel_panel *panel = &connector->panel;
>> +	u32 pwm_ctl, val;
>> +
>> +	panel->backlight.controller = dev_priv->vbt.backlight.controller;
>> +
>> +	pwm_ctl = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
>> +
>> +	panel->backlight.active_low_pwm = pwm_ctl &
>BXT_BLC_PWM_POLARITY;
>> +	panel->backlight.max =
>> +		I915_READ(BXT_BLC_PWM_FREQ(panel->backlight.controller));
>> +
>> +	if (!panel->backlight.max)
>> +		panel->backlight.max = get_backlight_max_vbt(connector);
>> +
>> +	if (!panel->backlight.max)
>> +		return -ENODEV;
>> +
>> +	val = bxt_get_backlight(connector);
>> +	val = intel_panel_compute_brightness(connector, val);
>> +	panel->backlight.level = clamp(val, panel->backlight.min,
>> +				       panel->backlight.max);
>> +
>> +	panel->backlight.enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;
>> +
>> +	return 0;
>> +}
>> +
>>  static int pwm_setup_backlight(struct intel_connector *connector,
>>  			       enum pipe pipe)
>>  {
>> @@ -1749,6 +1835,14 @@ intel_panel_init_backlight_funcs(struct intel_panel
>*panel)
>>  		panel->backlight.set = bxt_set_backlight;
>>  		panel->backlight.get = bxt_get_backlight;
>>  		panel->backlight.hz_to_pwm = bxt_hz_to_pwm;
>> +		panel->backlight.hz_to_pwm = bxt_hz_to_pwm;
>
>This diff should not be here.

Ah! Nice catch... Will rebase again and send. 
Thanks a lot.

Anusha

>-DK
>
>
>> +	} else if (HAS_PCH_CNP(dev_priv)) {
>> +		panel->backlight.setup = cnp_setup_backlight;
>> +		panel->backlight.enable = cnp_enable_backlight;
>> +		panel->backlight.disable = cnp_disable_backlight;
>> +		panel->backlight.set = bxt_set_backlight;
>> +		panel->backlight.get = bxt_get_backlight;
>> +		panel->backlight.hz_to_pwm = cnp_hz_to_pwm;
>>  	} else if (HAS_PCH_LPT(dev_priv) || HAS_PCH_SPT(dev_priv) ||
>>  		   HAS_PCH_KBP(dev_priv)) {
>>  		panel->backlight.setup = lpt_setup_backlight;



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