/* * 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_display_types.h" #include "intel_dp_aux_backlight.h" static void set_aux_backlight_enable(struct intel_dp *intel_dp, bool enable) { u8 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", 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 u32 intel_dp_aux_get_backlight(struct intel_connector *connector) { struct intel_dp *intel_dp = intel_attached_dp(connector); u8 read_val[2] = { 0x0 }; u8 mode_reg; u16 level = 0; if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg) != 1) { DRM_DEBUG_KMS("Failed to read the DPCD register 0x%x\n", DP_EDP_BACKLIGHT_MODE_SET_REGISTER); return 0; } /* * If we're not in DPCD control mode yet, the programmed brightness * value is meaningless and we should assume max brightness */ if ((mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) != DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) return connector->panel.backlight.max; 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(const struct drm_connector_state *conn_state, u32 level) { struct intel_connector *connector = to_intel_connector(conn_state->connector); struct intel_dp *intel_dp = intel_attached_dp(connector); u8 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; } } /* * Set PWM Frequency divider to match desired frequency in vbt. * The PWM Frequency is calculated as 27Mhz / (F x P). * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h) * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h) */ static bool intel_dp_aux_set_pwm_freq(struct intel_connector *connector) { struct drm_i915_private *dev_priv = to_i915(connector->base.dev); struct intel_dp *intel_dp = intel_attached_dp(connector); const u8 pn = connector->panel.backlight.pwmgen_bit_count; int freq, fxp, f, fxp_actual, fxp_min, fxp_max; freq = dev_priv->vbt.backlight.pwm_freq_hz; if (!freq) { DRM_DEBUG_KMS("Use panel default backlight frequency\n"); return false; } fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq); f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255); fxp_actual = f << pn; /* Ensure frequency is within 25% of desired value */ fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); if (fxp_min > fxp_actual || fxp_actual > fxp_max) { DRM_DEBUG_KMS("Actual frequency out of range\n"); return false; } if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_FREQ_SET, (u8) f) < 0) { DRM_DEBUG_KMS("Failed to write aux backlight freq\n"); return false; } return true; } static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_state, const struct drm_connector_state *conn_state) { struct intel_connector *connector = to_intel_connector(conn_state->connector); struct intel_dp *intel_dp = intel_attached_dp(connector); struct intel_panel *panel = &connector->panel; u8 dpcd_buf, new_dpcd_buf, edp_backlight_mode; if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) != 1) { DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n", DP_EDP_BACKLIGHT_MODE_SET_REGISTER); return; } new_dpcd_buf = dpcd_buf; edp_backlight_mode = dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; switch (edp_backlight_mode) { case DP_EDP_BACKLIGHT_CONTROL_MODE_PWM: case DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET: case DP_EDP_BACKLIGHT_CONTROL_MODE_PRODUCT: new_dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; new_dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, panel->backlight.pwmgen_bit_count) < 0) DRM_DEBUG_KMS("Failed to write aux pwmgen bit count\n"); break; /* Do nothing when it is already DPCD mode */ case DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD: default: break; } if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) if (intel_dp_aux_set_pwm_freq(connector)) new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE; if (new_dpcd_buf != dpcd_buf) { if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf) < 0) { DRM_DEBUG_KMS("Failed to write aux backlight mode\n"); } } intel_dp_aux_set_backlight(conn_state, connector->panel.backlight.level); set_aux_backlight_enable(intel_dp, true); } static void intel_dp_aux_disable_backlight(const struct drm_connector_state *old_conn_state) { set_aux_backlight_enable(enc_to_intel_dp(to_intel_encoder(old_conn_state->best_encoder)), false); } static u32 intel_dp_aux_calc_max_backlight(struct intel_connector *connector) { struct drm_i915_private *i915 = to_i915(connector->base.dev); struct intel_dp *intel_dp = intel_attached_dp(connector); struct intel_panel *panel = &connector->panel; u32 max_backlight = 0; int freq, fxp, fxp_min, fxp_max, fxp_actual, f = 1; u8 pn, pn_min, pn_max; if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, &pn) == 1) { pn &= DP_EDP_PWMGEN_BIT_COUNT_MASK; max_backlight = (1 << pn) - 1; } /* Find desired value of (F x P) * Note that, if F x P is out of supported range, the maximum value or * minimum value will applied automatically. So no need to check that. */ freq = i915->vbt.backlight.pwm_freq_hz; DRM_DEBUG_KMS("VBT defined backlight frequency %u Hz\n", freq); if (!freq) { DRM_DEBUG_KMS("Use panel default backlight frequency\n"); return max_backlight; } fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq); /* Use highest possible value of Pn for more granularity of brightness * adjustment while satifying the conditions below. * - Pn is in the range of Pn_min and Pn_max * - F is in the range of 1 and 255 * - FxP is within 25% of desired value. * Note: 25% is arbitrary value and may need some tweak. */ if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min) != 1) { DRM_DEBUG_KMS("Failed to read pwmgen bit count cap min\n"); return max_backlight; } if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max) != 1) { DRM_DEBUG_KMS("Failed to read pwmgen bit count cap max\n"); return max_backlight; } pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK; pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK; fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) { DRM_DEBUG_KMS("VBT defined backlight frequency out of range\n"); return max_backlight; } for (pn = pn_max; pn >= pn_min; pn--) { f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255); fxp_actual = f << pn; if (fxp_min <= fxp_actual && fxp_actual <= fxp_max) break; } DRM_DEBUG_KMS("Using eDP pwmgen bit count of %d\n", pn); if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT, pn) < 0) { DRM_DEBUG_KMS("Failed to write aux pwmgen bit count\n"); return max_backlight; } panel->backlight.pwmgen_bit_count = pn; max_backlight = (1 << pn) - 1; return max_backlight; } static int intel_dp_aux_setup_backlight(struct intel_connector *connector, enum pipe pipe) { struct intel_panel *panel = &connector->panel; panel->backlight.max = intel_dp_aux_calc_max_backlight(connector); if (!panel->backlight.max) return -ENODEV; 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 = intel_attached_dp(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[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; struct intel_dp *intel_dp = enc_to_intel_dp(intel_connector->encoder); struct drm_device *dev = intel_connector->base.dev; struct drm_i915_private *dev_priv = to_i915(dev); if (i915_modparams.enable_dpcd_backlight == 0 || !intel_dp_aux_display_control_capable(intel_connector)) return -ENODEV; /* * There are a lot of machines that don't advertise the backlight * control interface to use properly in their VBIOS, :\ */ if (dev_priv->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE && i915_modparams.enable_dpcd_backlight != 1 && !drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks, DP_QUIRK_FORCE_DPCD_BACKLIGHT)) { DRM_DEV_INFO(dev->dev, "Panel advertises DPCD backlight support, but " "VBT disagrees. If your backlight controls " "don't work try booting with " "i915.enable_dpcd_backlight=1. If your machine " "needs this, please file a _new_ bug report on " "drm/i915, see " FDO_BUG_URL " for details.\n"); 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; }