On Mon, 16 Nov 2015, Yetunde Adebisi <yetundex.adebisi@xxxxxxxxx> wrote: > This patch adds support for eDP backlight control using DPCD registers to > backlight hooks in intel_panel. > > It checks for backlight control over AUX channel capability and sets up > function pointers to get and set the backlight brightness level if > supported. > > v2: Moved backlight functions from intel_dp.c into a new file > intel_dp_aux_backlight.c. Also moved reading of eDP display control > registers to intel_dp_get_dpcd > > v3: Correct some formatting mistakes > > This patch depends on http://patchwork.freedesktop.org/patch/64253/ > > Cc: Bob Paauwe <bob.j.paauwe@xxxxxxxxx> > Cc: Jani Nikula <jani.nikula@xxxxxxxxx> > Acked-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> > Signed-off-by: Yetunde Adebisi <yetundex.adebisi@xxxxxxxxx> > --- > drivers/gpu/drm/i915/Makefile | 1 + > drivers/gpu/drm/i915/intel_dp.c | 16 ++- > drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 177 ++++++++++++++++++++++++++ > drivers/gpu/drm/i915/intel_drv.h | 6 + > drivers/gpu/drm/i915/intel_panel.c | 4 + > 5 files changed, 198 insertions(+), 6 deletions(-) > create mode 100644 drivers/gpu/drm/i915/intel_dp_aux_backlight.c > > diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile > index 0851de07..7a1db3d 100644 > --- a/drivers/gpu/drm/i915/Makefile > +++ b/drivers/gpu/drm/i915/Makefile > @@ -77,6 +77,7 @@ i915-y += dvo_ch7017.o \ > dvo_tfp410.o \ > intel_crt.o \ > intel_ddi.o \ > + intel_dp_aux_backlight.o\ Space before \ please. > intel_dp_link_training.o \ > intel_dp_mst.o \ > intel_dp.o \ > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index 8071247..22e0241 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -3156,7 +3156,7 @@ static void chv_dp_post_pll_disable(struct intel_encoder *encoder) > * Sinks are *supposed* to come up within 1ms from an off state, but we're also > * supposed to retry 3 times per the spec. > */ > -static ssize_t > +ssize_t > intel_dp_dpcd_read_wake(struct drm_dp_aux *aux, unsigned int offset, > void *buffer, size_t size) > { > @@ -3823,7 +3823,6 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) > struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); > struct drm_device *dev = dig_port->base.base.dev; > struct drm_i915_private *dev_priv = dev->dev_private; > - uint8_t rev; > > if (intel_dp_dpcd_read_wake(&intel_dp->aux, 0x000, intel_dp->dpcd, > sizeof(intel_dp->dpcd)) < 0) > @@ -3859,6 +3858,14 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) > DRM_DEBUG_KMS("PSR2 %s on sink", > dev_priv->psr.psr2_support ? "supported" : "not supported"); > } > + > + /* Read the eDP Display control capabilities registers */ You need to clear intel_dp->dpcd_edp here. > + if ((intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) && > + (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_EDP_DPCD_REV, > + intel_dp->dpcd_edp, sizeof(intel_dp->dpcd_edp)) == > + sizeof(intel_dp->dpcd_edp))) > + DRM_DEBUG_KMS("EDP DPCD : %*ph\n", (int) sizeof(intel_dp->dpcd_edp), > + intel_dp->dpcd_edp); > } > > DRM_DEBUG_KMS("Display Port TPS3 support: source %s, sink %s\n", > @@ -3866,10 +3873,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) > yesno(drm_dp_tps3_supported(intel_dp->dpcd))); > > /* Intermediate frequency support */ > - if (is_edp(intel_dp) && > - (intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) && > - (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) && > - (rev >= 0x03)) { /* eDp v1.4 or higher */ > + if (is_edp(intel_dp) && (intel_dp->dpcd_edp[0] >= 0x03)) { /* eDp v1.4 or higher */ > __le16 sink_rates[DP_MAX_SUPPORTED_RATES]; > int i; > > diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c > new file mode 100644 > index 0000000..190c5d9 > --- /dev/null > +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c > @@ -0,0 +1,177 @@ > +/* > + * Copyright © 2015 Intel Corporation > + * > + * Permission is hereby granted, free of charge, to any person obtaining a > + * copy of this software and associated documentation files (the "Software"), > + * to deal in the Software without restriction, including without limitation > + * the rights to use, copy, modify, merge, publish, distribute, sublicense, > + * and/or sell copies of the Software, and to permit persons to whom the > + * Software is furnished to do so, subject to the following conditions: > + * > + * The above copyright notice and this permission notice (including the next > + * paragraph) shall be included in all copies or substantial portions of the > + * Software. > + * > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS > + * IN THE SOFTWARE. > + * > + */ > + > +#include "intel_drv.h" > + > +static bool is_aux_backlight_enabled(struct drm_dp_aux *aux) > +{ > + uint8_t read_val = 0; > + > + if (intel_dp_dpcd_read_wake(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, > + &read_val, sizeof(read_val)) < 0) > + DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n", > + DP_EDP_DISPLAY_CONTROL_REGISTER); > + > + return read_val & DP_EDP_BACKLIGHT_ENABLE; > +} > + > +static void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable) > +{ > + uint8_t reg_val = 0; > + > + if (intel_dp_dpcd_read_wake(&intel_dp->aux, > + DP_EDP_DISPLAY_CONTROL_REGISTER, > + ®_val, sizeof(reg_val)) < 0) { > + DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n", > + DP_EDP_DISPLAY_CONTROL_REGISTER); > + return; > + } > + if (enable) > + reg_val |= DP_EDP_BACKLIGHT_ENABLE; > + else > + reg_val &= ~(DP_EDP_BACKLIGHT_ENABLE); > + > + if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, > + reg_val) < 0) { > + DRM_DEBUG_KMS("Failed to %s aux backlight\n", > + enable ? "enable" : "disable"); > + } > +} > + > +/* > + * Read the current backlight value from DPCD register(s) based > + * on if 8-bit(MSB) or 16-bit(MSB and LSB) values are supported > + */ > +static uint32_t intel_dp_aux_get_backlight(struct intel_connector *connector) > +{ > + struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); > + uint8_t read_val[2] = { 0x0 }; > + uint16_t level = 0; > + > + if (intel_dp_dpcd_read_wake(&intel_dp->aux, > + DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, > + &read_val, sizeof(read_val)) < 0) { > + DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n", > + DP_EDP_BACKLIGHT_BRIGHTNESS_MSB); > + return 0; > + } > + level = read_val[0]; > + if (intel_dp->dpcd_edp[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) > + level = (read_val[0] << 8 | read_val[1]); > + > + return level; > +} > + > +/* > + * Sends the current backlight level over the aux channel, checking if its using > + * 8-bit or 16 bit value (MSB and LSB) > + */ > +static void > +intel_dp_aux_set_backlight(struct intel_connector *connector, u32 level) > +{ > + struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); > + uint8_t vals[2] = { 0x0 }; > + > + DRM_DEBUG_KMS("Level 0x%x\n", level); The caller of the hook does debug logging already. > + vals[0] = level; > + > + /* Write the MSB and/or LSB */ > + if (intel_dp->dpcd_edp[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) { > + vals[0] = (level & 0xFF00) >> 8; > + vals[1] = (level & 0xFF); > + } > + if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, > + vals, sizeof(vals)) < 0) { > + DRM_DEBUG_KMS("Failed to write aux backlight level\n"); > + return; > + } > +} > + > +static void intel_dp_aux_enable_backlight(struct intel_connector *connector) > +{ > + set_aux_backlight_enable(enc_to_intel_dp(&connector->encoder->base), true); > +} > + > +static void intel_dp_aux_disable_backlight(struct intel_connector *connector) > +{ > + set_aux_backlight_enable(enc_to_intel_dp(&connector->encoder->base), false); > +} > + > +static int intel_dp_aux_setup_backlight(struct intel_connector *connector, > + enum pipe pipe) > +{ > + struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); > + struct intel_panel *panel = &connector->panel; > + > + if (intel_dp->dpcd_edp[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) > + panel->backlight.max = 0xFFFF; > + else > + panel->backlight.max = 0xFF; > + > + panel->backlight.min = 0; > + > + panel->backlight.level = intel_dp_aux_get_backlight(connector); > + panel->backlight.enabled = is_aux_backlight_enabled(&intel_dp->aux); > + > + return 0; > +} > + > +static bool intel_dp_aux_display_control_capable(struct intel_connector *connector) > +{ > + struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); > + uint8_t dpcd_buf = 0; > + > + /* Check the eDP Display control capabilities registers to determine if > + * the panel can support backlight control over the aux channel*/ > + > + if (intel_dp->dpcd_edp[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP && > + (intel_dp->dpcd_edp[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) && > + (intel_dp->dpcd_edp[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) && > + ((intel_dp_dpcd_read_wake(&intel_dp->aux, > + DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf, 1) == 1) && > + ((dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) == > + DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD))) { The DP_EDP_BACKLIGHT_MODE_SET_REGISTER is a read/write register for configuration. You can also *set* the control method. Apparently this now trusts the BIOS to have written the right value here. I am not sure this is the right way to go. How about checking that aux control is possible *and* pwm control is not possible, and then setting the mode accordingly? Also, the power-on default for the mode is DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET, which means a power cycle will fix the brightness to a preset level and the brightness adjustment will cease to work. Did you test this? I think you should write the mode in backlight enable. > + > + DRM_DEBUG_KMS("AUX Backlight Control Supported!\n"); > + > + return true; > + } > + return false; > +} > + > +int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector) > +{ > + struct intel_panel *panel = &intel_connector->panel; > + > + if (!intel_dp_aux_display_control_capable(intel_connector)) > + return -ENODEV; > + > + panel->backlight.setup = intel_dp_aux_setup_backlight; > + panel->backlight.enable = intel_dp_aux_enable_backlight; > + panel->backlight.disable = intel_dp_aux_disable_backlight; > + panel->backlight.set = intel_dp_aux_set_backlight; > + panel->backlight.get = intel_dp_aux_get_backlight; > + > + return 0; > +} > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index ad17288..095df8d 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -758,6 +758,7 @@ struct intel_dp { > uint8_t dpcd[DP_RECEIVER_CAP_SIZE]; > uint8_t psr_dpcd[EDP_PSR_RECEIVER_CAP_SIZE]; > uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS]; > + uint8_t dpcd_edp[EDP_DISPLAY_CTL_CAP_SIZE]; > /* sink rates as reported by DP_SUPPORTED_LINK_RATES */ > uint8_t num_sink_rates; > int sink_rates[DP_MAX_SUPPORTED_RATES]; > @@ -1279,6 +1280,11 @@ void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock, > bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp); > bool > intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE]); > +ssize_t intel_dp_dpcd_read_wake(struct drm_dp_aux *aux, unsigned int offset, > + void *buffer, size_t size); > + > +/* intel_dp_aux_backlight.c */ > +int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector); > > /* intel_dp_mst.c */ > int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id); > diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c > index a24df35..7da49b5 100644 > --- a/drivers/gpu/drm/i915/intel_panel.c > +++ b/drivers/gpu/drm/i915/intel_panel.c > @@ -1744,6 +1744,10 @@ intel_panel_init_backlight_funcs(struct intel_panel *panel) > struct drm_device *dev = intel_connector->base.dev; > struct drm_i915_private *dev_priv = dev->dev_private; > > + if (intel_connector->base.connector_type == DRM_MODE_CONNECTOR_eDP && > + intel_dp_aux_init_backlight_funcs(intel_connector) == 0) > + return; > + > if (IS_BROXTON(dev)) { > panel->backlight.setup = bxt_setup_backlight; > panel->backlight.enable = bxt_enable_backlight; -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
