Commit e7156c83 authored by Yetunde Adebisi's avatar Yetunde Adebisi Committed by Jani Nikula

drm/i915: Add Backlight Control using DPCD for eDP connectors (v9)

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
v6: Check DP_EDP_BACKLIGHT_PIN_ENABLE_CAP is disabled before setting up AUX
backlight control. To fix BLM_PWM_ENABLE igt test warnings on bdw_ultra
v7: Add enable_dpcd_backlight module parameter.
v8: Rebase onto latest drm-intel-nightly branch
v9: Remove changes to intel_dp_dpcd_read_wake
    Split addition edp_dpcd variable into a separate patch

Cc: Bob Paauwe <bob.j.paauwe@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarYetunde Adebisi <yetundex.adebisi@intel.com>
[Jani: whitepace changes to appease checkpatch]
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459865452-9138-4-git-send-email-yetundex.adebisi@intel.com
parent 86ee27b5
......@@ -81,6 +81,7 @@ 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 \
......
......@@ -58,6 +58,7 @@ struct i915_params i915 __read_mostly = {
.guc_log_level = -1,
.enable_dp_mst = true,
.inject_load_failure = 0,
.enable_dpcd_backlight = false,
};
module_param_named(modeset, i915.modeset, int, 0400);
......@@ -210,3 +211,6 @@ MODULE_PARM_DESC(enable_dp_mst,
module_param_named_unsafe(inject_load_failure, i915.inject_load_failure, uint, 0400);
MODULE_PARM_DESC(inject_load_failure,
"Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)");
module_param_named(enable_dpcd_backlight, i915.enable_dpcd_backlight, bool, 0600);
MODULE_PARM_DESC(enable_dpcd_backlight,
"Enable support for DPCD backlight control (default:false)");
......@@ -61,6 +61,7 @@ struct i915_params {
bool verbose_state_checks;
bool nuclear_pageflip;
bool enable_dp_mst;
bool enable_dpcd_backlight;
};
extern struct i915_params i915 __read_mostly;
......
/*
* 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,
&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) != 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;
}
......@@ -1337,6 +1337,9 @@ 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]);
/* 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);
void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
......
......@@ -1718,6 +1718,10 @@ 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;
......
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