diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp_aux_backlight.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 172 |
1 files changed, 172 insertions, 0 deletions
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 000000000000..6532e226db29 --- /dev/null +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c @@ -0,0 +1,172 @@ +/* + * 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 void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable) +{ + uint8_t reg_val = 0; + + 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", + 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) != 1) { + 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 (drm_dp_dpcd_read(&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->edp_dpcd[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 }; + + vals[0] = level; + + /* Write the MSB and/or LSB */ + if (intel_dp->edp_dpcd[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) +{ + struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); + uint8_t dpcd_buf = 0; + + set_aux_backlight_enable(intel_dp, true); + + if ((drm_dp_dpcd_readb(&intel_dp->aux, + DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) == 1) && + ((dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) == + DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET)) + drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, + (dpcd_buf | DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD)); +} + +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; + + intel_dp_aux_enable_backlight(connector); + + if (intel_dp->edp_dpcd[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 = panel->backlight.level != 0; + + 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); + + /* 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[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) && + !((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP) || + (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))) { + 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 (!i915.enable_dpcd_backlight) + return -ENODEV; + + 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; +} |