--- /dev/null
+/*
+ * 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;
+}
projects / kernel.git / commitdiff