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
v4: Updated to use AUX backlight control if PWM control is not possible
(Jani)
v5: Moved call to initialize backlight registers to dp_aux_setup_backlight
This patch depends on http://patchwork.freedesktop.org/patch/64253/
Cc: Bob Paauwe <bob.j.paa...@intel.com>
Cc: Jani Nikula <jani.nik...@intel.com>
Acked-by: Jesse Barnes <jbar...@virtuousgeek.org>
Signed-off-by: Yetunde Adebisi <yetundex.adeb...@intel.com>
---
drivers/gpu/drm/i915/Makefile | 1 +
drivers/gpu/drm/i915/intel_dp.c | 17 ++-
drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 169 ++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_drv.h | 6 +
drivers/gpu/drm/i915/intel_panel.c | 4 +
5 files changed, 191 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..41250cc 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 \
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 796e3d3..b9dabad 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3186,7 +3186,7 @@ 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)
{
@@ -3853,7 +3853,6 @@ 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)
@@ -3889,6 +3888,15 @@ 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 */
+ memset(intel_dp->edp_dpcd, 0, sizeof(intel_dp->edp_dpcd));
+ 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->edp_dpcd,
sizeof(intel_dp->edp_dpcd)) ==
+
sizeof(intel_dp->edp_dpcd)))
+ DRM_DEBUG_KMS("EDP DPCD : %*ph\n", (int)
sizeof(intel_dp->edp_dpcd),
+ intel_dp->edp_dpcd);
}
DRM_DEBUG_KMS("Display Port TPS3 support: source %s, sink %s\n",
@@ -3896,10 +3904,7 @@ 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->edp_dpcd[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..3ef28e7
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
@@ -0,0 +1,169 @@
+/*
+ * 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 (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->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 ((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_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[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 (!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 bdfe403..06663cb 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -781,6 +781,7 @@ 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 edp_dpcd[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];
@@ -1307,6 +1308,11 @@ 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 21ee647..941c6fe 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -1720,6 +1720,10 @@ intel_panel_init_backlight_funcs(struct intel_panel
*panel)
container_of(panel, struct intel_connector, panel);
struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+ if (connector->base.connector_type == DRM_MODE_CONNECTOR_eDP &&
+ intel_dp_aux_init_backlight_funcs(connector) == 0)
+ return;
+
if (IS_BROXTON(dev_priv)) {
panel->backlight.setup = bxt_setup_backlight;
panel->backlight.enable = bxt_enable_backlight;
--
1.9.3
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