On Wed, Mar 06, 2024 at 02:29:15PM +0530, Suraj Kandpal wrote:
> As of now whenerver HDR is switched on we use the PWM to change the
> backlight as opposed to AUX based backlight changes in terms of nits.
> This patch writes to the appropriate DPCD registers to enable aux
> based backlight using values in nits.
>
> --v2
> -Fix max_cll and max_fall assignment [Jani]
> -Fix the size sent in drm_dpcd_write [Jani]
>
> Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
> ---
> .../drm/i915/display/intel_dp_aux_backlight.c | 30 ++++++++++++++-----
> 1 file changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> index 4f58efdc688a..1b6f14dacf3b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -40,11 +40,6 @@
> #include "intel_dp.h"
> #include "intel_dp_aux_backlight.h"
>
> -/* TODO:
> - * Implement HDR, right now we just implement the bare minimum to bring us
> back into SDR mode so we
> - * can make people's backlights work in the mean time
> - */
> -
> /*
> * DP AUX registers for Intel's proprietary HDR backlight interface. We
> define
> * them here since we'll likely be the only driver to ever use these.
> @@ -221,7 +216,7 @@ intel_dp_aux_hdr_set_backlight(const struct
> drm_connector_state *conn_state, u32
> struct intel_connector *connector =
> to_intel_connector(conn_state->connector);
> struct intel_panel *panel = &connector->panel;
>
> - if (panel->backlight.edp.intel.sdr_uses_aux) {
> + if (panel->backlight.edp.intel.sdr_uses_aux ||
> conn_state->hdr_output_metadata) {
> intel_dp_aux_hdr_set_aux_backlight(conn_state, level);
> } else {
> const u32 pwm_level = intel_backlight_level_to_pwm(connector,
> level);
> @@ -251,8 +246,15 @@ intel_dp_aux_hdr_enable_backlight(const struct
> intel_crtc_state *crtc_state,
> }
>
> ctrl = old_ctrl;
> - if (panel->backlight.edp.intel.sdr_uses_aux) {
> + if (panel->backlight.edp.intel.sdr_uses_aux ||
> conn_state->hdr_output_metadata) {
> ctrl |= INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE;
> +
> + if (conn_state->hdr_output_metadata) {
> + ctrl |= INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_ENABLE;
> + ctrl |= INTEL_EDP_HDR_TCON_2084_DECODE_ENABLE;
> + ctrl |= INTEL_EDP_HDR_TCON_2020_GAMUT_ENABLE;
> + }
Wasn't bunch of this stuff supposed to be only used with older hw,
and more recent panels were supposed to pick this up more or less
automagically from the HDR metadata?
I seem to also recall that there are a bunch of capability bits we
should probably be checking somewhere...
> +
> intel_dp_aux_hdr_set_aux_backlight(conn_state, level);
> } else {
> u32 pwm_level = intel_backlight_level_to_pwm(connector, level);
> @@ -292,9 +294,11 @@ intel_dp_aux_hdr_setup_backlight(struct intel_connector
> *connector, enum pipe pi
> {
> struct drm_i915_private *i915 = to_i915(connector->base.dev);
> struct intel_panel *panel = &connector->panel;
> + struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
> struct drm_luminance_range_info *luminance_range =
> &connector->base.display_info.luminance_range;
> int ret;
> + u8 buf[4];
>
> drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] SDR backlight is controlled
> through %s\n",
> connector->base.base.id, connector->base.name,
> @@ -318,11 +322,21 @@ intel_dp_aux_hdr_setup_backlight(struct intel_connector
> *connector, enum pipe pi
> panel->backlight.min = 0;
> }
>
> + buf[0] = connector->base.hdr_sink_metadata.hdmi_type1.max_cll & 0xFF;
> + buf[1] = (connector->base.hdr_sink_metadata.hdmi_type1.max_cll &
> 0xFF00) >> 8;
> + buf[2] = connector->base.hdr_sink_metadata.hdmi_type1.max_fall & 0xFF;
> + buf[3] = (connector->base.hdr_sink_metadata.hdmi_type1.max_fall &
> 0xFF00) >> 8;
> +
> + ret = drm_dp_dpcd_write(&intel_dp->aux,
> INTEL_EDP_HDR_CONTENT_LUMINANCE, buf,
> + sizeof(buf));
> + if (ret < 0)
> + drm_dbg_kms(&i915->drm,
> + "Not able to write content luminence to DPCD
> register err:-%d\n", ret);
> +
> drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] Using AUX HDR interface for
> backlight control (range %d..%d)\n",
> connector->base.base.id, connector->base.name,
> panel->backlight.min, panel->backlight.max);
>
> -
> panel->backlight.level = intel_dp_aux_hdr_get_backlight(connector,
> pipe);
> panel->backlight.enabled = panel->backlight.level != 0;
>
> --
> 2.43.2
--
Ville Syrjälä
Intel
