[Intel-gfx] [PATCH 04/67] drm/i915/cnp: Add Backlight support to CNP PCH.

[Ville Syrjälä]

On Thu, Apr 06, 2017 at 12:15:00PM -0700, Rodrigo Vivi wrote:
> Backlight support on Cannonpoint is a lot
> likely Broxton, but with only one controller (0).

This being the PCH backlight obviously. I guess we still don't have any
use for the CPU backlight?

Oh, since the utility pin is on the CPU I think we should perhaps add
HAS_PCH_SPLIT checks around the useage of the utility pin in the BXT
backlight functions, or some comments. Or perhaps even split out CNP+
vs. BXT entirely? Otherwise I think people might get confused by the
utility pin references.

> 
> Also other main changes/differences:
> 
> - PWM clock frequency = Raw clock frequency = 19.2 MHz or
>   24 MHz.  Value is found in SFUSE_STRAP.
> - PWM increment = 1
> 
> 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.
> 
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_panel.c | 19 +++++++++++++++++--
>  1 file changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> index cb50c52..1978bec 100644
> --- a/drivers/gpu/drm/i915/intel_panel.c
> +++ b/drivers/gpu/drm/i915/intel_panel.c
> @@ -1247,6 +1247,18 @@ static u32 bxt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
>  }
>  
>  /*
> + * 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);
> +}
> +
> +/*
>   * SPT: This value represents the period of the PWM stream in clock periods
>   * multiplied by 16 (default increment) or 128 (alternate increment selected in
>   * SCHICKEN_1 bit 0). PWM clock is 24 MHz.
> @@ -1742,13 +1754,16 @@ void intel_panel_destroy_backlight(struct drm_connector *connector)
>  	    intel_dsi_dcs_init_backlight_funcs(connector) == 0)
>  		return;
>  
> -	if (IS_GEN9_LP(dev_priv)) {
> +	if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv)) {
>  		panel->backlight.setup = bxt_setup_backlight;
>  		panel->backlight.enable = bxt_enable_backlight;
>  		panel->backlight.disable = bxt_disable_backlight;
>  		panel->backlight.set = bxt_set_backlight;
>  		panel->backlight.get = bxt_get_backlight;
> -		panel->backlight.hz_to_pwm = bxt_hz_to_pwm;
> +		if (IS_GEN9_LP(dev_priv))
> +			panel->backlight.hz_to_pwm = bxt_hz_to_pwm;
> +		else
> +			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;
> -- 
> 1.9.1
> 
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-- 
Ville Syrjälä
Intel OTC