From: Suraj Kandpal Date: Fri, 20 Jun 2025 06:34:40 +0000 (+0530) Subject: drm/dp: Modify drm_edp_backlight_set_level X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f2db78e37fe7f95dde96abe2a2a8412f8f519658;p=thirdparty%2Flinux.git drm/dp: Modify drm_edp_backlight_set_level Modify drm_edp_backlight_set_level to be able to set the value for register in DP_EDP_PANEL_TARGET_LUMINANCE_VALUE. We multiply the level with 1000 since we get the value in Nits and the register accepts it in milliNits. --v2 -Add comment regarding the unit [Arun] Signed-off-by: Suraj Kandpal Reviewed-by: Arun R Murthy Link: https://lore.kernel.org/r/20250620063445.3603086-9-suraj.kandpal@intel.com --- diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c index c22d97e0f1870..c29c327a72afc 100644 --- a/drivers/gpu/drm/display/drm_dp_helper.c +++ b/drivers/gpu/drm/display/drm_dp_helper.c @@ -3944,20 +3944,28 @@ int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_bac u32 level) { int ret; - u8 buf[2] = { 0 }; + unsigned int offset = DP_EDP_BACKLIGHT_BRIGHTNESS_MSB; + u8 buf[3] = { 0 }; /* The panel uses the PWM for controlling brightness levels */ - if (!bl->aux_set) + if (!(bl->aux_set || bl->luminance_set)) return 0; - if (bl->lsb_reg_used) { + if (bl->luminance_set) { + level = level * 1000; + level &= 0xffffff; + buf[0] = (level & 0x0000ff); + buf[1] = (level & 0x00ff00) >> 8; + buf[2] = (level & 0xff0000) >> 16; + offset = DP_EDP_PANEL_TARGET_LUMINANCE_VALUE; + } else if (bl->lsb_reg_used) { buf[0] = (level & 0xff00) >> 8; buf[1] = (level & 0x00ff); } else { buf[0] = level; } - ret = drm_dp_dpcd_write_data(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, sizeof(buf)); + ret = drm_dp_dpcd_write_data(aux, offset, buf, sizeof(buf)); if (ret < 0) { drm_err(aux->drm_dev, "%s: Failed to write aux backlight level: %d\n",