1 /* 2 * Copyright © 2015 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 */ 24 25 #include "intel_drv.h" 26 27 static void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable) 28 { 29 uint8_t reg_val = 0; 30 31 if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, 32 ®_val) < 0) { 33 DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n", 34 DP_EDP_DISPLAY_CONTROL_REGISTER); 35 return; 36 } 37 if (enable) 38 reg_val |= DP_EDP_BACKLIGHT_ENABLE; 39 else 40 reg_val &= ~(DP_EDP_BACKLIGHT_ENABLE); 41 42 if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, 43 reg_val) != 1) { 44 DRM_DEBUG_KMS("Failed to %s aux backlight\n", 45 enable ? "enable" : "disable"); 46 } 47 } 48 49 /* 50 * Read the current backlight value from DPCD register(s) based 51 * on if 8-bit(MSB) or 16-bit(MSB and LSB) values are supported 52 */ 53 static uint32_t intel_dp_aux_get_backlight(struct intel_connector *connector) 54 { 55 struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); 56 uint8_t read_val[2] = { 0x0 }; 57 uint16_t level = 0; 58 59 if (drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, 60 &read_val, sizeof(read_val)) < 0) { 61 DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n", 62 DP_EDP_BACKLIGHT_BRIGHTNESS_MSB); 63 return 0; 64 } 65 level = read_val[0]; 66 if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) 67 level = (read_val[0] << 8 | read_val[1]); 68 69 return level; 70 } 71 72 /* 73 * Sends the current backlight level over the aux channel, checking if its using 74 * 8-bit or 16 bit value (MSB and LSB) 75 */ 76 static void 77 intel_dp_aux_set_backlight(struct intel_connector *connector, u32 level) 78 { 79 struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); 80 uint8_t vals[2] = { 0x0 }; 81 82 vals[0] = level; 83 84 /* Write the MSB and/or LSB */ 85 if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) { 86 vals[0] = (level & 0xFF00) >> 8; 87 vals[1] = (level & 0xFF); 88 } 89 if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, 90 vals, sizeof(vals)) < 0) { 91 DRM_DEBUG_KMS("Failed to write aux backlight level\n"); 92 return; 93 } 94 } 95 96 static void intel_dp_aux_enable_backlight(struct intel_connector *connector) 97 { 98 struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); 99 uint8_t dpcd_buf = 0; 100 101 set_aux_backlight_enable(intel_dp, true); 102 103 if ((drm_dp_dpcd_readb(&intel_dp->aux, 104 DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) == 1) && 105 ((dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) == 106 DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET)) 107 drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, 108 (dpcd_buf | DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD)); 109 } 110 111 static void intel_dp_aux_disable_backlight(struct intel_connector *connector) 112 { 113 set_aux_backlight_enable(enc_to_intel_dp(&connector->encoder->base), false); 114 } 115 116 static int intel_dp_aux_setup_backlight(struct intel_connector *connector, 117 enum i915_pipe pipe) 118 { 119 struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); 120 struct intel_panel *panel = &connector->panel; 121 122 if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) 123 panel->backlight.max = 0xFFFF; 124 else 125 panel->backlight.max = 0xFF; 126 127 panel->backlight.min = 0; 128 panel->backlight.level = intel_dp_aux_get_backlight(connector); 129 130 panel->backlight.enabled = panel->backlight.level != 0; 131 132 return 0; 133 } 134 135 static bool 136 intel_dp_aux_display_control_capable(struct intel_connector *connector) 137 { 138 struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); 139 140 /* Check the eDP Display control capabilities registers to determine if 141 * the panel can support backlight control over the aux channel 142 */ 143 if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP && 144 (intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) && 145 !((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP) || 146 (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))) { 147 DRM_DEBUG_KMS("AUX Backlight Control Supported!\n"); 148 return true; 149 } 150 return false; 151 } 152 153 int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector) 154 { 155 struct intel_panel *panel = &intel_connector->panel; 156 157 if (!i915.enable_dpcd_backlight) 158 return -ENODEV; 159 160 if (!intel_dp_aux_display_control_capable(intel_connector)) 161 return -ENODEV; 162 163 panel->backlight.setup = intel_dp_aux_setup_backlight; 164 panel->backlight.enable = intel_dp_aux_enable_backlight; 165 panel->backlight.disable = intel_dp_aux_disable_backlight; 166 panel->backlight.set = intel_dp_aux_set_backlight; 167 panel->backlight.get = intel_dp_aux_get_backlight; 168 169 return 0; 170 } 171