| Message ID | 20180316025659.217423-3-amstan@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Mar 15, 2018 at 07:56:59PM -0700, Alexandru M Stan wrote: > Configure the DPCD registers for the backlight to respect the pwm frequency > of the input. We sometimes don't want it to generate its own. > > Signed-off-by: Alexandru M Stan <amstan@chromium.org> I wonder a bit whether we should have some generic infrastructure in the dp helpers itself to apply quirks like this. It's more-or-less what we have for EDID quirking. But then I guess for panels a lot of it is specific to the bridge/encoder/panel combo and given platform, so probably not much use for reuse across boards/platforms. External displays would be a different story. I guess you can count that as an Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> on the overall thing, but pls get bridge folks to review this too. -Daniel > --- > > drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 48 ++++++++++++++++++++++ > drivers/gpu/drm/bridge/analogix/analogix_dp_core.h | 1 + > 2 files changed, 49 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > index 5c52307146c7..b830403be8eb 100644 > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > @@ -916,6 +916,46 @@ static irqreturn_t analogix_dp_irq_thread(int irq, void *arg) > return IRQ_HANDLED; > } > > +static int analogix_dp_backlight_pwm_passthru(struct analogix_dp_device *dp) > +{ > + u8 value; > + const u8 expected_cap = DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP | > + DP_EDP_BACKLIGHT_FREQ_PWM_PIN_PASSTHRU_CAP; > + int ret = 0; > + > + ret = drm_dp_dpcd_readb(&dp->aux, DP_EDP_BACKLIGHT_ADJUSTMENT_CAP, > + &value); > + if (ret != 1) { > + DRM_DEV_ERROR(dp->dev, > + "backlight PWM passthru: Can't read BACKLIGHT_ADJUSTMENT_CAP\n"); > + return ret; > + } > + > + if ((value & expected_cap) != expected_cap) { > + DRM_DEV_ERROR(dp->dev, > + "panel doesn't support backlight PWM passthru, BACKLIGHT_ADJUSTMENT_CAP=0x%02x\n", > + value); > + return -1; > + } > + > + ret = drm_dp_dpcd_readb(&dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, > + &value); > + if (ret != 1) { > + DRM_DEV_ERROR(dp->dev, > + "backlight PWM passthru: Can't read BACKLIGHT_MODE_SET_REGISTER\n"); > + return ret; > + } > + > + value |= DP_EDP_BACKLIGHT_FREQ_PWM_PIN_PASSTHRU_ENABLE; > + ret = drm_dp_dpcd_writeb(&dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, > + value); > + if (ret != 1) { > + DRM_DEV_ERROR(dp->dev, > + "backlight PWM passthru: Can't write BACKLIGHT_MODE_SET_REGISTER\n"); > + } > + return ret; > +} > + > static void analogix_dp_commit(struct analogix_dp_device *dp) > { > int ret; > @@ -954,6 +994,12 @@ static void analogix_dp_commit(struct analogix_dp_device *dp) > dp->psr_enable = analogix_dp_detect_sink_psr(dp); > if (dp->psr_enable) > analogix_dp_enable_sink_psr(dp); > + > + if (dp->backlight_pwm_passthru) { > + if (analogix_dp_backlight_pwm_passthru(dp) != 1) > + DRM_DEV_ERROR(dp->dev, > + "Could not enable backlight pwm pin passthru.\n"); > + } > } > > /* > @@ -1424,6 +1470,8 @@ analogix_dp_bind(struct device *dev, struct drm_device *drm_dev, > if (IS_ERR(dp->reg_base)) > return ERR_CAST(dp->reg_base); > > + dp->backlight_pwm_passthru = > + of_property_read_bool(dev->of_node, "backlight-pwm-passthru"); > dp->force_hpd = of_property_read_bool(dev->of_node, "force-hpd"); > > dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0); > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h > index 6a96ef7e6934..aea51413e78e 100644 > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h > @@ -171,6 +171,7 @@ struct analogix_dp_device { > struct phy *phy; > int dpms_mode; > int hpd_gpio; > + bool backlight_pwm_passthru; > bool force_hpd; > bool psr_enable; > bool fast_train_support; > -- > 2.13.5 >
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index 5c52307146c7..b830403be8eb 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -916,6 +916,46 @@ static irqreturn_t analogix_dp_irq_thread(int irq, void *arg) return IRQ_HANDLED; } +static int analogix_dp_backlight_pwm_passthru(struct analogix_dp_device *dp) +{ + u8 value; + const u8 expected_cap = DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP | + DP_EDP_BACKLIGHT_FREQ_PWM_PIN_PASSTHRU_CAP; + int ret = 0; + + ret = drm_dp_dpcd_readb(&dp->aux, DP_EDP_BACKLIGHT_ADJUSTMENT_CAP, + &value); + if (ret != 1) { + DRM_DEV_ERROR(dp->dev, + "backlight PWM passthru: Can't read BACKLIGHT_ADJUSTMENT_CAP\n"); + return ret; + } + + if ((value & expected_cap) != expected_cap) { + DRM_DEV_ERROR(dp->dev, + "panel doesn't support backlight PWM passthru, BACKLIGHT_ADJUSTMENT_CAP=0x%02x\n", + value); + return -1; + } + + ret = drm_dp_dpcd_readb(&dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, + &value); + if (ret != 1) { + DRM_DEV_ERROR(dp->dev, + "backlight PWM passthru: Can't read BACKLIGHT_MODE_SET_REGISTER\n"); + return ret; + } + + value |= DP_EDP_BACKLIGHT_FREQ_PWM_PIN_PASSTHRU_ENABLE; + ret = drm_dp_dpcd_writeb(&dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, + value); + if (ret != 1) { + DRM_DEV_ERROR(dp->dev, + "backlight PWM passthru: Can't write BACKLIGHT_MODE_SET_REGISTER\n"); + } + return ret; +} + static void analogix_dp_commit(struct analogix_dp_device *dp) { int ret; @@ -954,6 +994,12 @@ static void analogix_dp_commit(struct analogix_dp_device *dp) dp->psr_enable = analogix_dp_detect_sink_psr(dp); if (dp->psr_enable) analogix_dp_enable_sink_psr(dp); + + if (dp->backlight_pwm_passthru) { + if (analogix_dp_backlight_pwm_passthru(dp) != 1) + DRM_DEV_ERROR(dp->dev, + "Could not enable backlight pwm pin passthru.\n"); + } } /* @@ -1424,6 +1470,8 @@ analogix_dp_bind(struct device *dev, struct drm_device *drm_dev, if (IS_ERR(dp->reg_base)) return ERR_CAST(dp->reg_base); + dp->backlight_pwm_passthru = + of_property_read_bool(dev->of_node, "backlight-pwm-passthru"); dp->force_hpd = of_property_read_bool(dev->of_node, "force-hpd"); dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0); diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h index 6a96ef7e6934..aea51413e78e 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h @@ -171,6 +171,7 @@ struct analogix_dp_device { struct phy *phy; int dpms_mode; int hpd_gpio; + bool backlight_pwm_passthru; bool force_hpd; bool psr_enable; bool fast_train_support;
Configure the DPCD registers for the backlight to respect the pwm frequency of the input. We sometimes don't want it to generate its own. Signed-off-by: Alexandru M Stan <amstan@chromium.org> --- drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 48 ++++++++++++++++++++++ drivers/gpu/drm/bridge/analogix/analogix_dp_core.h | 1 + 2 files changed, 49 insertions(+)