Add option to allow choosing how to adjust brightness if
panel supports both PWM pin and AUX channel.
Signed-off-by: Puthikorn Voravootivat <put...@chromium.org>
---
drivers/gpu/drm/i915/i915_params.c | 8 ++++---
drivers/gpu/drm/i915/i915_params.h | 2 +-
drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 31 ++++++++++++++++++++++-----
3 files changed, 32 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_params.c
b/drivers/gpu/drm/i915/i915_params.c
index b6a7e363d076..13cf3f1572ab 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -63,7 +63,7 @@ struct i915_params i915 __read_mostly = {
.huc_firmware_path = NULL,
.enable_dp_mst = true,
.inject_load_failure = 0,
- .enable_dpcd_backlight = false,
+ .enable_dpcd_backlight = -1,
.enable_gvt = false,
};
@@ -246,9 +246,11 @@ MODULE_PARM_DESC(enable_dp_mst,
module_param_named_unsafe(inject_load_failure, i915.inject_load_failure, uint,
0400);
MODULE_PARM_DESC(inject_load_failure,
"Force an error after a number of failure check points (0:disabled
(default), N:force failure at the Nth failure check point)");
-module_param_named(enable_dpcd_backlight, i915.enable_dpcd_backlight, bool,
0600);
+module_param_named(enable_dpcd_backlight, i915.enable_dpcd_backlight, int,
0600);
MODULE_PARM_DESC(enable_dpcd_backlight,
- "Enable support for DPCD backlight control (default:false)");
+ "Enable support for DPCD backlight control "
+ "(-1:disable (default), 0:Use PWM pin if both supported, "
+ "1:Use DPCD if both supported");
module_param_named(enable_gvt, i915.enable_gvt, bool, 0400);
MODULE_PARM_DESC(enable_gvt,
diff --git a/drivers/gpu/drm/i915/i915_params.h
b/drivers/gpu/drm/i915/i915_params.h
index 34148cc8637c..ac02efce6e22 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -66,7 +66,7 @@
func(bool, verbose_state_checks); \
func(bool, nuclear_pageflip); \
func(bool, enable_dp_mst); \
- func(bool, enable_dpcd_backlight); \
+ func(int, enable_dpcd_backlight); \
func(bool, enable_gvt)
#define MEMBER(T, member) T member
diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
index d32c06583e0b..16ba1924308d 100644
--- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
@@ -28,6 +28,10 @@ static void set_aux_backlight_enable(struct intel_dp
*intel_dp, bool enable)
{
uint8_t reg_val = 0;
+ /* Early return when display use other mechanism to enable backlight. */
+ if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP))
+ return;
+
if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER,
®_val) < 0) {
DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n",
@@ -39,6 +43,9 @@ static void set_aux_backlight_enable(struct intel_dp
*intel_dp, bool enable)
else
reg_val &= ~(DP_EDP_BACKLIGHT_ENABLE);
+ /* TODO: If the panel also support enabling backlight via BL_ENABLE pin,
+ * the backlight will be enabled again in _intel_edp_backlight_on()
+ */
if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER,
reg_val) != 1) {
DRM_DEBUG_KMS("Failed to %s aux backlight\n",
@@ -164,21 +171,35 @@ intel_dp_aux_display_control_capable(struct
intel_connector *connector)
/* Check the eDP Display control capabilities registers to determine if
* the panel can support backlight control over the aux channel
*/
- if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP &&
- (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) &&
- !((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP) ||
- (intel_dp->edp_dpcd[2] &
DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))) {
+ if ((intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) &&
+ (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) {
DRM_DEBUG_KMS("AUX Backlight Control Supported!\n");
return true;
}
return false;
}
+static bool
+intel_dp_pwm_pin_display_control_capable(struct intel_connector *connector)
+{
+ struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
+
+ /* Check the eDP Display control capabilities registers to determine if
+ * the panel can support backlight control via BL_PWM_DIM eDP pin
+ */
+ return (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) &&
+ (intel_dp->edp_dpcd[2] &
DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP);
+}
+
int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
{
struct intel_panel *panel = &intel_connector->panel;
- if (!i915.enable_dpcd_backlight)
+ if (i915.enable_dpcd_backlight == -1)
+ return -ENODEV;
+
+ if (i915.enable_dpcd_backlight == 0 &&
+ intel_dp_pwm_pin_display_control_capable(intel_connector))
return -ENODEV;
if (!intel_dp_aux_display_control_capable(intel_connector))
--
2.13.0.303.g4ebf302169-goog
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