[Intel-gfx] [PATCH v7 07/23] drm/i915/icl: Program TA_TIMING_PARAM registers

[Madhav Chauhan]

On 10/15/2018 7:57 PM, Jani Nikula wrote:
> From: Madhav Chauhan <madhav.chauhan at intel.com>
>
> This patch programs D-PHY timing parameters for the
> bus turn around flow(in escape clocks) only if dsi link
> frequency <=800 MHz using DPHY_TA_TIMING_PARAM and its
> identical register DSI_TA_TIMING_PARAM (inside DSI
> Controller within the Display Core).
>
> v2: Changes
>      - Don't use KHz() macro (Ville/Jani N)
>      - Use newly defined bitfields
>
> v3 by Jani:
>   - Use intel_dsi_bitrate() in favor of a new field
>   - Remove redundant parens

v3 changes looks fine to me.

Regards,
Madhav

>
> Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>   drivers/gpu/drm/i915/icl_dsi.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/icl_dsi.c b/drivers/gpu/drm/i915/icl_dsi.c
> index 9602b6532028..f9df3a7fa66b 100644
> --- a/drivers/gpu/drm/i915/icl_dsi.c
> +++ b/drivers/gpu/drm/i915/icl_dsi.c
> @@ -309,6 +309,27 @@ static void gen11_dsi_setup_dphy_timings(struct intel_encoder *encoder)
>   		I915_WRITE(DSI_DATA_TIMING_PARAM(port),
>   			   intel_dsi->dphy_data_lane_reg);
>   	}
> +
> +	/*
> +	 * If DSI link operating at or below an 800 MHz,
> +	 * TA_SURE should be override and programmed to
> +	 * a value '0' inside TA_PARAM_REGISTERS otherwise
> +	 * leave all fields at HW default values.
> +	 */
> +	if (intel_dsi_bitrate(intel_dsi) <= 800000) {
> +		for_each_dsi_port(port, intel_dsi->ports) {
> +			tmp = I915_READ(DPHY_TA_TIMING_PARAM(port));
> +			tmp &= ~TA_SURE_MASK;
> +			tmp |= TA_SURE_OVERRIDE | TA_SURE(0);
> +			I915_WRITE(DPHY_TA_TIMING_PARAM(port), tmp);
> +
> +			/* shadow register inside display core */
> +			tmp = I915_READ(DSI_TA_TIMING_PARAM(port));
> +			tmp &= ~TA_SURE_MASK;
> +			tmp |= TA_SURE_OVERRIDE | TA_SURE(0);
> +			I915_WRITE(DSI_TA_TIMING_PARAM(port), tmp);
> +		}
> +	}
>   }
>   
>   static void gen11_dsi_enable_port_and_phy(struct intel_encoder *encoder)