On Wed, Feb 01, 2017 at 06:14:40PM +0530, Shashank Sharma wrote:
> Geminilake platform has a native HDMI 2.0 controller, and is
> capable of driving pixel-clocks upto 594Mhz. HDMI 2.0 spec
> mendates scrambling for these higher clocks, for reduced RF footprint.
>
> This patch checks if the monitor supports scrambling, and if required,
> enables it during the modeset.
>
> Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 2 ++
> drivers/gpu/drm/i915/intel_ddi.c | 5 +++++
> drivers/gpu/drm/i915/intel_drv.h | 2 ++
> drivers/gpu/drm/i915/intel_hdmi.c | 42 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 51 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 495b789..cc85892 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7807,6 +7807,8 @@ enum {
> #define TRANS_DDI_EDP_INPUT_C_ONOFF (6<<12)
> #define TRANS_DDI_DP_VC_PAYLOAD_ALLOC (1<<8)
> #define TRANS_DDI_BFI_ENABLE (1<<4)
> +#define TRANS_DDI_HIGH_TMDS_CHAR_RATE (1<<4)
> +#define TRANS_DDI_HDMI_SCRAMBLING (1<<0)
>
> /* DisplayPort Transport Control */
> #define _DP_TP_CTL_A 0x64040
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 9a9a670..aea81ce 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1278,6 +1278,11 @@ void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
> temp |= TRANS_DDI_MODE_SELECT_HDMI;
> else
> temp |= TRANS_DDI_MODE_SELECT_DVI;
> +
> + if (IS_GEMINILAKE(dev_priv)) {
> + temp |= intel_hdmi_check_scrambling(intel_encoder,
> + &intel_crtc->config->base.adjusted_mode);
> + }
> } else if (type == INTEL_OUTPUT_ANALOG) {
> temp |= TRANS_DDI_MODE_SELECT_FDI;
> temp |= (intel_crtc->config->fdi_lanes - 1) << 1;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 393f243..aafce7f 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1588,6 +1588,8 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
> bool intel_hdmi_compute_config(struct intel_encoder *encoder,
> struct intel_crtc_state *pipe_config,
> struct drm_connector_state *conn_state);
> +uint32_t intel_hdmi_check_scrambling(struct intel_encoder *intel_encoder,
> + struct drm_display_mode *mode);
> void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable);
>
>
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> index ebae2bd..92dd9bc 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1795,6 +1795,48 @@ static void intel_hdmi_destroy(struct drm_connector *connector)
> intel_hdmi->aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
> }
>
> +static void
> +intel_hdmi_enable_scrambling(struct drm_connector *connector)
> +{
> + struct drm_i915_private *dev_priv = connector->dev->dev_private;
> + struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
> + struct i2c_adapter *adapter =
> + intel_gmbus_get_adapter(dev_priv, intel_hdmi->ddc_bus);
> +
> + if (!drm_enable_scrambling(connector, adapter, true))
> + DRM_ERROR("Request to enable scrambling failed\n");
> +}
I don't like hiding this somewhere deep like this. It should be
somewhere much higher up.
And I'm thinkign we might want to track the scrambler state
in the crtc state.
> +
> +uint32_t intel_hdmi_check_scrambling(struct intel_encoder *intel_encoder,
> + struct drm_display_mode *mode)
> +{
> + struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&intel_encoder->base);
> + struct drm_connector *connector = &intel_hdmi->attached_connector->base;
> + struct drm_hdmi_info *hdmi_info = &connector->display_info.hdmi_info;
> + uint32_t hdmi_config = 0;
> +
> + DRM_DEBUG_KMS("Checking scrambling for enc:%s connector:%s\n",
> + intel_encoder->base.name, connector->name);
> +
> + if (mode->clock < 340000) {
> + if (hdmi_info->scr_info.low_clocks) {
> + intel_hdmi_enable_scrambling(connector);
> + hdmi_config |= TRANS_DDI_HDMI_SCRAMBLING;
> + }
> + return hdmi_config;
> + }
> +
> + /* Enable scrambling for clocks > 340M */
> + if (hdmi_info->scr_info.supported) {
> + intel_hdmi_enable_scrambling(connector);
> + hdmi_config |= TRANS_DDI_HDMI_SCRAMBLING;
> + }
> +
> + /* Scrambling or not, if clock > 340M, set high char rate */
> + hdmi_config |= TRANS_DDI_HIGH_TMDS_CHAR_RATE;
> + return hdmi_config;
> +}
> +
> static u8 intel_hdmi_ddc_pin(struct drm_i915_private *dev_priv,
> enum port port)
> {
> --
> 1.9.1
--
Ville Syrjälä
Intel OTC
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