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/*
* 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)
{
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
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,
&reg_val) < 0) {
drm_dbg_kms(&i915->drm, "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_dbg_kms(&i915->drm, "Failed to %s aux backlight\n",
enable ? "enable" : "disable");
}
}
static bool intel_dp_aux_backlight_dpcd_mode(struct intel_connector *connector)
{
struct intel_dp *intel_dp = intel_attached_dp(connector);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
u8 mode_reg;
if (drm_dp_dpcd_readb(&intel_dp->aux,
DP_EDP_BACKLIGHT_MODE_SET_REGISTER,
&mode_reg) != 1) {
drm_dbg_kms(&i915->drm,
"Failed to read the DPCD register 0x%x\n",
DP_EDP_BACKLIGHT_MODE_SET_REGISTER);
return false;
}
return (mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) ==
DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
}
/*
* 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);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
u8 read_val[2] = { 0x0 };
u16 level = 0;
/*
* If we're not in DPCD control mode yet, the programmed brightness
* value is meaningless and we should assume max brightness
*/
if (!intel_dp_aux_backlight_dpcd_mode(connector))
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_dbg_kms(&i915->drm, "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);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
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_dbg_kms(&i915->drm,
"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_dbg_kms(&dev_priv->drm,
"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_dbg_kms(&dev_priv->drm, "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_dbg_kms(&dev_priv->drm,
"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 drm_i915_private *i915 = dp_to_i915(intel_dp);
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_dbg_kms(&i915->drm, "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_dbg_kms(&i915->drm,
"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_dbg_kms(&i915->drm,
"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_dbg_kms(&i915->drm, "VBT defined backlight frequency %u Hz\n",
freq);
if (!freq) {
drm_dbg_kms(&i915->drm,
"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_dbg_kms(&i915->drm,
"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_dbg_kms(&i915->drm,
"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_dbg_kms(&i915->drm,
"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_dbg_kms(&i915->drm, "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_dbg_kms(&i915->drm,
"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 = intel_dp_aux_backlight_dpcd_mode(connector) &&
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);
struct drm_i915_private *i915 = dp_to_i915(intel_dp);
/* 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_dbg_kms(&i915->drm, "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_i915_private *i915 = dp_to_i915(intel_dp);
if (i915->params.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 (i915->vbt.backlight.type !=
INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE &&
i915->params.enable_dpcd_backlight != 1 &&
!drm_dp_has_quirk(&intel_dp->desc, intel_dp->edid_quirks,
DP_QUIRK_FORCE_DPCD_BACKLIGHT)) {
drm_info(&i915->drm,
"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;
}