Quelle  intel_backlight.c   Sprache: unbekannt

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2021 Intel Corporation
 */

#include <linux/backlight.h>
#include <linux/kernel.h>
#include <linux/pwm.h>
#include <linux/string_helpers.h>
#include <acpi/video.h>

#include <drm/drm_file.h>
#include <drm/drm_print.h>

#include "i915_reg.h"
#include "i915_utils.h"
#include "intel_backlight.h"
#include "intel_backlight_regs.h"
#include "intel_connector.h"
#include "intel_de.h"
#include "intel_display_regs.h"
#include "intel_display_rpm.h"
#include "intel_display_types.h"
#include "intel_dp_aux_backlight.h"
#include "intel_dsi_dcs_backlight.h"
#include "intel_panel.h"
#include "intel_pci_config.h"
#include "intel_pps.h"
#include "intel_quirks.h"

/**
 * scale - scale values from one range to another
 * @source_val: value in range [@source_min..@source_max]
 * @source_min: minimum legal value for @source_val
 * @source_max: maximum legal value for @source_val
 * @target_min: corresponding target value for @source_min
 * @target_max: corresponding target value for @source_max
 *
 * Return @source_val in range [@source_min..@source_max] scaled to range
 * [@target_min..@target_max].
 */
static u32 scale(u32 source_val,
   u32 source_min, u32 source_max,
   u32 target_min, u32 target_max)
{
 u64 target_val;

 if (WARN_ON(source_min >= source_max) ||
     WARN_ON(target_min > target_max))
  return target_min;

 /* defensive */
 source_val = clamp(source_val, source_min, source_max);

 /* avoid overflows */
 target_val = mul_u32_u32(source_val - source_min,
     target_max - target_min);
 target_val = DIV_ROUND_CLOSEST_ULL(target_val, source_max - source_min);
 target_val += target_min;

 return target_val;
}

/*
 * Scale user_level in range [0..user_max] to [0..hw_max], clamping the result
 * to [hw_min..hw_max].
 */
static u32 clamp_user_to_hw(struct intel_connector *connector,
       u32 user_level, u32 user_max)
{
 struct intel_panel *panel = &connector->panel;
 u32 hw_level;

 hw_level = scale(user_level, 0, user_max, 0, panel->backlight.max);
 hw_level = clamp(hw_level, panel->backlight.min, panel->backlight.max);

 return hw_level;
}

/* Scale hw_level in range [hw_min..hw_max] to [0..user_max]. */
static u32 scale_hw_to_user(struct intel_connector *connector,
       u32 hw_level, u32 user_max)
{
 struct intel_panel *panel = &connector->panel;

 return scale(hw_level, panel->backlight.min, panel->backlight.max,
       0, user_max);
}

u32 intel_backlight_invert_pwm_level(struct intel_connector *connector, u32 val)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 drm_WARN_ON(display->drm, panel->backlight.pwm_level_max == 0);

 if (display->params.invert_brightness < 0)
  return val;

 if (display->params.invert_brightness > 0 ||
     intel_has_quirk(display, QUIRK_INVERT_BRIGHTNESS)) {
  return panel->backlight.pwm_level_max - val + panel->backlight.pwm_level_min;
 }

 return val;
}

void intel_backlight_set_pwm_level(const struct drm_connector_state *conn_state, u32 val)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] set backlight PWM = %d\n",
      connector->base.base.id, connector->base.name, val);
 panel->backlight.pwm_funcs->set(conn_state, val);
}

u32 intel_backlight_level_to_pwm(struct intel_connector *connector, u32 val)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 drm_WARN_ON_ONCE(display->drm,
    panel->backlight.max == 0 || panel->backlight.pwm_level_max == 0);

 val = scale(val, panel->backlight.min, panel->backlight.max,
      panel->backlight.pwm_level_min, panel->backlight.pwm_level_max);

 return intel_backlight_invert_pwm_level(connector, val);
}

u32 intel_backlight_level_from_pwm(struct intel_connector *connector, u32 val)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 drm_WARN_ON_ONCE(display->drm,
    panel->backlight.max == 0 || panel->backlight.pwm_level_max == 0);

 if (display->params.invert_brightness > 0 ||
     (display->params.invert_brightness == 0 &&
      intel_has_quirk(display, QUIRK_INVERT_BRIGHTNESS)))
  val = panel->backlight.pwm_level_max - (val - panel->backlight.pwm_level_min);

 return scale(val, panel->backlight.pwm_level_min, panel->backlight.pwm_level_max,
       panel->backlight.min, panel->backlight.max);
}

static u32 lpt_get_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);

 return intel_de_read(display, BLC_PWM_PCH_CTL2) & BACKLIGHT_DUTY_CYCLE_MASK;
}

static u32 pch_get_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);

 return intel_de_read(display, BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
}

static u32 i9xx_get_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 val;

 val = intel_de_read(display, BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
 if (DISPLAY_VER(display) < 4)
  val >>= 1;

 if (panel->backlight.combination_mode) {
  struct pci_dev *pdev = to_pci_dev(display->drm->dev);
  u8 lbpc;

  pci_read_config_byte(pdev, LBPC, &lbpc);
  val *= lbpc;
 }

 return val;
}

static u32 vlv_get_backlight(struct intel_connector *connector, enum pipe pipe)
{
 struct intel_display *display = to_intel_display(connector);

 if (drm_WARN_ON(display->drm, pipe != PIPE_A && pipe != PIPE_B))
  return 0;

 return intel_de_read(display, VLV_BLC_PWM_CTL(pipe)) & BACKLIGHT_DUTY_CYCLE_MASK;
}

static u32 bxt_get_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 return intel_de_read(display, BXT_BLC_PWM_DUTY(panel->backlight.controller));
}

static u32 ext_pwm_get_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_panel *panel = &connector->panel;
 struct pwm_state state;

 pwm_get_state(panel->backlight.pwm, &state);
 return pwm_get_relative_duty_cycle(&state, 100);
}

static void lpt_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 u32 val;

 val = intel_de_read(display, BLC_PWM_PCH_CTL2) & ~BACKLIGHT_DUTY_CYCLE_MASK;
 intel_de_write(display, BLC_PWM_PCH_CTL2, val | level);
}

static void pch_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 u32 tmp;

 tmp = intel_de_read(display, BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
 intel_de_write(display, BLC_PWM_CPU_CTL, tmp | level);
}

static void i9xx_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 tmp, mask;

 drm_WARN_ON(display->drm, panel->backlight.pwm_level_max == 0);

 if (panel->backlight.combination_mode) {
  struct pci_dev *pdev = to_pci_dev(display->drm->dev);
  u8 lbpc;

  lbpc = level * 0xfe / panel->backlight.pwm_level_max + 1;
  level /= lbpc;
  pci_write_config_byte(pdev, LBPC, lbpc);
 }

 if (DISPLAY_VER(display) == 4) {
  mask = BACKLIGHT_DUTY_CYCLE_MASK;
 } else {
  level <<= 1;
  mask = BACKLIGHT_DUTY_CYCLE_MASK_PNV;
 }

 tmp = intel_de_read(display, BLC_PWM_CTL) & ~mask;
 intel_de_write(display, BLC_PWM_CTL, tmp | level);
}

static void vlv_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 enum pipe pipe = to_intel_crtc(conn_state->crtc)->pipe;
 u32 tmp;

 tmp = intel_de_read(display, VLV_BLC_PWM_CTL(pipe)) & ~BACKLIGHT_DUTY_CYCLE_MASK;
 intel_de_write(display, VLV_BLC_PWM_CTL(pipe), tmp | level);
}

static void bxt_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 intel_de_write(display, BXT_BLC_PWM_DUTY(panel->backlight.controller), level);
}

static void ext_pwm_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;

 pwm_set_relative_duty_cycle(&panel->backlight.pwm_state, level, 100);
 pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state);
}

static void
intel_panel_actually_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] set backlight level = %d\n",
      connector->base.base.id, connector->base.name, level);

 panel->backlight.funcs->set(conn_state, level);
}

/* set backlight brightness to level in range [0..max], assuming hw min is
 * respected.
 */
void intel_backlight_set_acpi(const struct drm_connector_state *conn_state,
         u32 user_level, u32 user_max)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 hw_level;

 /*
 * Lack of crtc may occur during driver init because
 * connection_mutex isn't held across the entire backlight
 * setup + modeset readout, and the BIOS can issue the
 * requests at any time.
 */
 if (!panel->backlight.present || !conn_state->crtc)
  return;

 mutex_lock(&display->backlight.lock);

 drm_WARN_ON(display->drm, panel->backlight.max == 0);

 hw_level = clamp_user_to_hw(connector, user_level, user_max);
 panel->backlight.level = hw_level;

 if (panel->backlight.device)
  panel->backlight.device->props.brightness =
   scale_hw_to_user(connector,
      panel->backlight.level,
      panel->backlight.device->props.max_brightness);

 if (panel->backlight.enabled)
  intel_panel_actually_set_backlight(conn_state, hw_level);

 mutex_unlock(&display->backlight.lock);
}

static void lpt_disable_backlight(const struct drm_connector_state *old_conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 u32 tmp;

 intel_backlight_set_pwm_level(old_conn_state, level);

 /*
 * Although we don't support or enable CPU PWM with LPT/SPT based
 * systems, it may have been enabled prior to loading the
 * driver. Disable to avoid warnings on LCPLL disable.
 *
 * This needs rework if we need to add support for CPU PWM on PCH split
 * platforms.
 */
 tmp = intel_de_read(display, BLC_PWM_CPU_CTL2);
 if (tmp & BLM_PWM_ENABLE) {
  drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] CPU backlight was enabled, disabling\n",
       connector->base.base.id, connector->base.name);
  intel_de_write(display, BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
 }

 intel_de_rmw(display, BLC_PWM_PCH_CTL1, BLM_PCH_PWM_ENABLE, 0);
}

static void pch_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
{
 struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 struct intel_display *display = to_intel_display(connector);

 intel_backlight_set_pwm_level(old_conn_state, val);

 intel_de_rmw(display, BLC_PWM_CPU_CTL2, BLM_PWM_ENABLE, 0);

 intel_de_rmw(display, BLC_PWM_PCH_CTL1, BLM_PCH_PWM_ENABLE, 0);
}

static void i9xx_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
{
 intel_backlight_set_pwm_level(old_conn_state, val);
}

static void i965_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
{
 struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 struct intel_display *display = to_intel_display(connector);

 intel_backlight_set_pwm_level(old_conn_state, val);

 intel_de_rmw(display, BLC_PWM_CTL2, BLM_PWM_ENABLE, 0);
}

static void vlv_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
{
 struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 enum pipe pipe = to_intel_crtc(old_conn_state->crtc)->pipe;

 intel_backlight_set_pwm_level(old_conn_state, val);

 intel_de_rmw(display, VLV_BLC_PWM_CTL2(pipe), BLM_PWM_ENABLE, 0);
}

static void bxt_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
{
 struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 intel_backlight_set_pwm_level(old_conn_state, val);

 intel_de_rmw(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
       BXT_BLC_PWM_ENABLE, 0);

 if (panel->backlight.controller == 1)
  intel_de_rmw(display, UTIL_PIN_CTL, UTIL_PIN_ENABLE, 0);
}

static void cnp_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
{
 struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 intel_backlight_set_pwm_level(old_conn_state, val);

 intel_de_rmw(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
       BXT_BLC_PWM_ENABLE, 0);
}

static void ext_pwm_disable_backlight(const struct drm_connector_state *old_conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 struct intel_panel *panel = &connector->panel;

 intel_backlight_set_pwm_level(old_conn_state, level);

 panel->backlight.pwm_state.enabled = false;
 pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state);
}

void intel_backlight_disable(const struct drm_connector_state *old_conn_state)
{
 struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 if (!panel->backlight.present)
  return;

 /*
 * Do not disable backlight on the vga_switcheroo path. When switching
 * away from i915, the other client may depend on i915 to handle the
 * backlight. This will leave the backlight on unnecessarily when
 * another client is not activated.
 */
 if (display->drm->switch_power_state == DRM_SWITCH_POWER_CHANGING) {
  drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] Skipping backlight disable on vga switch\n",
       connector->base.base.id, connector->base.name);
  return;
 }

 mutex_lock(&display->backlight.lock);

 if (panel->backlight.device)
  panel->backlight.device->props.power = BACKLIGHT_POWER_OFF;
 panel->backlight.enabled = false;
 panel->backlight.funcs->disable(old_conn_state, 0);

 mutex_unlock(&display->backlight.lock);
}

static void lpt_enable_backlight(const struct intel_crtc_state *crtc_state,
     const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 pch_ctl1, pch_ctl2;

 pch_ctl1 = intel_de_read(display, BLC_PWM_PCH_CTL1);
 if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] PCH backlight already enabled\n",
       connector->base.base.id, connector->base.name);
  pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
  intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1);
 }

 if (HAS_PCH_LPT(display))
  intel_de_rmw(display, SOUTH_CHICKEN2, LPT_PWM_GRANULARITY,
        panel->backlight.alternate_pwm_increment ?
        LPT_PWM_GRANULARITY : 0);
 else
  intel_de_rmw(display, SOUTH_CHICKEN1, SPT_PWM_GRANULARITY,
        panel->backlight.alternate_pwm_increment ?
        SPT_PWM_GRANULARITY : 0);

 pch_ctl2 = panel->backlight.pwm_level_max << 16;
 intel_de_write(display, BLC_PWM_PCH_CTL2, pch_ctl2);

 pch_ctl1 = 0;
 if (panel->backlight.active_low_pwm)
  pch_ctl1 |= BLM_PCH_POLARITY;

 /* After LPT, override is the default. */
 if (HAS_PCH_LPT(display))
  pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;

 intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1);
 intel_de_posting_read(display, BLC_PWM_PCH_CTL1);
 intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);

 /* This won't stick until the above enable. */
 intel_backlight_set_pwm_level(conn_state, level);
}

static void pch_enable_backlight(const struct intel_crtc_state *crtc_state,
     const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
 u32 cpu_ctl2, pch_ctl1, pch_ctl2;

 cpu_ctl2 = intel_de_read(display, BLC_PWM_CPU_CTL2);
 if (cpu_ctl2 & BLM_PWM_ENABLE) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] CPU backlight already enabled\n",
       connector->base.base.id, connector->base.name);
  cpu_ctl2 &= ~BLM_PWM_ENABLE;
  intel_de_write(display, BLC_PWM_CPU_CTL2, cpu_ctl2);
 }

 pch_ctl1 = intel_de_read(display, BLC_PWM_PCH_CTL1);
 if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] PCH backlight already enabled\n",
       connector->base.base.id, connector->base.name);
  pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
  intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1);
 }

 if (cpu_transcoder == TRANSCODER_EDP)
  cpu_ctl2 = BLM_TRANSCODER_EDP;
 else
  cpu_ctl2 = BLM_PIPE(cpu_transcoder);
 intel_de_write(display, BLC_PWM_CPU_CTL2, cpu_ctl2);
 intel_de_posting_read(display, BLC_PWM_CPU_CTL2);
 intel_de_write(display, BLC_PWM_CPU_CTL2, cpu_ctl2 | BLM_PWM_ENABLE);

 /* This won't stick until the above enable. */
 intel_backlight_set_pwm_level(conn_state, level);

 pch_ctl2 = panel->backlight.pwm_level_max << 16;
 intel_de_write(display, BLC_PWM_PCH_CTL2, pch_ctl2);

 pch_ctl1 = 0;
 if (panel->backlight.active_low_pwm)
  pch_ctl1 |= BLM_PCH_POLARITY;

 intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1);
 intel_de_posting_read(display, BLC_PWM_PCH_CTL1);
 intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
}

static void i9xx_enable_backlight(const struct intel_crtc_state *crtc_state,
      const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 ctl, freq;

 ctl = intel_de_read(display, BLC_PWM_CTL);
 if (ctl & BACKLIGHT_DUTY_CYCLE_MASK_PNV) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] backlight already enabled\n",
       connector->base.base.id, connector->base.name);
  intel_de_write(display, BLC_PWM_CTL, 0);
 }

 freq = panel->backlight.pwm_level_max;
 if (panel->backlight.combination_mode)
  freq /= 0xff;

 ctl = freq << 17;
 if (panel->backlight.combination_mode)
  ctl |= BLM_LEGACY_MODE;
 if (display->platform.pineview && panel->backlight.active_low_pwm)
  ctl |= BLM_POLARITY_PNV;

 intel_de_write(display, BLC_PWM_CTL, ctl);
 intel_de_posting_read(display, BLC_PWM_CTL);

 /* XXX: combine this into above write? */
 intel_backlight_set_pwm_level(conn_state, level);

 /*
 * Needed to enable backlight on some 855gm models. BLC_HIST_CTL is
 * 855gm only, but checking for gen2 is safe, as 855gm is the only gen2
 * that has backlight.
 */
 if (DISPLAY_VER(display) == 2)
  intel_de_write(display, BLC_HIST_CTL, BLM_HISTOGRAM_ENABLE);
}

static void i965_enable_backlight(const struct intel_crtc_state *crtc_state,
      const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 enum pipe pipe = to_intel_crtc(conn_state->crtc)->pipe;
 u32 ctl, ctl2, freq;

 ctl2 = intel_de_read(display, BLC_PWM_CTL2);
 if (ctl2 & BLM_PWM_ENABLE) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] backlight already enabled\n",
       connector->base.base.id, connector->base.name);
  ctl2 &= ~BLM_PWM_ENABLE;
  intel_de_write(display, BLC_PWM_CTL2, ctl2);
 }

 freq = panel->backlight.pwm_level_max;
 if (panel->backlight.combination_mode)
  freq /= 0xff;

 ctl = freq << 16;
 intel_de_write(display, BLC_PWM_CTL, ctl);

 ctl2 = BLM_PIPE(pipe);
 if (panel->backlight.combination_mode)
  ctl2 |= BLM_COMBINATION_MODE;
 if (panel->backlight.active_low_pwm)
  ctl2 |= BLM_POLARITY_I965;
 intel_de_write(display, BLC_PWM_CTL2, ctl2);
 intel_de_posting_read(display, BLC_PWM_CTL2);
 intel_de_write(display, BLC_PWM_CTL2, ctl2 | BLM_PWM_ENABLE);

 intel_backlight_set_pwm_level(conn_state, level);
}

static void vlv_enable_backlight(const struct intel_crtc_state *crtc_state,
     const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 enum pipe pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
 u32 ctl, ctl2;

 ctl2 = intel_de_read(display, VLV_BLC_PWM_CTL2(pipe));
 if (ctl2 & BLM_PWM_ENABLE) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] backlight already enabled\n",
       connector->base.base.id, connector->base.name);
  ctl2 &= ~BLM_PWM_ENABLE;
  intel_de_write(display, VLV_BLC_PWM_CTL2(pipe), ctl2);
 }

 ctl = panel->backlight.pwm_level_max << 16;
 intel_de_write(display, VLV_BLC_PWM_CTL(pipe), ctl);

 /* XXX: combine this into above write? */
 intel_backlight_set_pwm_level(conn_state, level);

 ctl2 = 0;
 if (panel->backlight.active_low_pwm)
  ctl2 |= BLM_POLARITY_I965;
 intel_de_write(display, VLV_BLC_PWM_CTL2(pipe), ctl2);
 intel_de_posting_read(display, VLV_BLC_PWM_CTL2(pipe));
 intel_de_write(display, VLV_BLC_PWM_CTL2(pipe), ctl2 | BLM_PWM_ENABLE);
}

static void bxt_enable_backlight(const struct intel_crtc_state *crtc_state,
     const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 enum pipe pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
 u32 pwm_ctl, val;

 /* Controller 1 uses the utility pin. */
 if (panel->backlight.controller == 1) {
  val = intel_de_read(display, UTIL_PIN_CTL);
  if (val & UTIL_PIN_ENABLE) {
   drm_dbg_kms(display->drm,
        "[CONNECTOR:%d:%s] utility pin already enabled\n",
        connector->base.base.id, connector->base.name);
   val &= ~UTIL_PIN_ENABLE;
   intel_de_write(display, UTIL_PIN_CTL, val);
  }

  val = 0;
  if (panel->backlight.util_pin_active_low)
   val |= UTIL_PIN_POLARITY;
  intel_de_write(display, UTIL_PIN_CTL,
          val | UTIL_PIN_PIPE(pipe) | UTIL_PIN_MODE_PWM | UTIL_PIN_ENABLE);
 }

 pwm_ctl = intel_de_read(display, BXT_BLC_PWM_CTL(panel->backlight.controller));
 if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] backlight already enabled\n",
       connector->base.base.id, connector->base.name);
  pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
  intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
          pwm_ctl);
 }

 intel_de_write(display, BXT_BLC_PWM_FREQ(panel->backlight.controller),
         panel->backlight.pwm_level_max);

 intel_backlight_set_pwm_level(conn_state, level);

 pwm_ctl = 0;
 if (panel->backlight.active_low_pwm)
  pwm_ctl |= BXT_BLC_PWM_POLARITY;

 intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller), pwm_ctl);
 intel_de_posting_read(display, BXT_BLC_PWM_CTL(panel->backlight.controller));
 intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
         pwm_ctl | BXT_BLC_PWM_ENABLE);
}

static void cnp_enable_backlight(const struct intel_crtc_state *crtc_state,
     const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 pwm_ctl;

 pwm_ctl = intel_de_read(display, BXT_BLC_PWM_CTL(panel->backlight.controller));
 if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
  drm_dbg_kms(display->drm, "backlight already enabled\n");
  pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
  intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
          pwm_ctl);
 }

 intel_de_write(display, BXT_BLC_PWM_FREQ(panel->backlight.controller),
         panel->backlight.pwm_level_max);

 intel_backlight_set_pwm_level(conn_state, level);

 pwm_ctl = 0;
 if (panel->backlight.active_low_pwm)
  pwm_ctl |= BXT_BLC_PWM_POLARITY;

 intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller), pwm_ctl);
 intel_de_posting_read(display, BXT_BLC_PWM_CTL(panel->backlight.controller));
 intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
         pwm_ctl | BXT_BLC_PWM_ENABLE);
}

static void ext_pwm_enable_backlight(const struct intel_crtc_state *crtc_state,
         const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_panel *panel = &connector->panel;

 pwm_set_relative_duty_cycle(&panel->backlight.pwm_state, level, 100);
 panel->backlight.pwm_state.enabled = true;
 pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state);
}

static void __intel_backlight_enable(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_panel *panel = &connector->panel;

 WARN_ON(panel->backlight.max == 0);

 if (panel->backlight.level < panel->backlight.min) {
  panel->backlight.level = panel->backlight.min;
  if (panel->backlight.device)
   panel->backlight.device->props.brightness =
    scale_hw_to_user(connector,
       panel->backlight.level,
       panel->backlight.device->props.max_brightness);
 }

 panel->backlight.funcs->enable(crtc_state, conn_state, panel->backlight.level);
 panel->backlight.enabled = true;
 if (panel->backlight.device)
  panel->backlight.device->props.power = BACKLIGHT_POWER_ON;
}

void intel_backlight_enable(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_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 enum pipe pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;

 if (!panel->backlight.present)
  return;

 drm_dbg_kms(display->drm, "pipe %c\n", pipe_name(pipe));

 mutex_lock(&display->backlight.lock);

 __intel_backlight_enable(crtc_state, conn_state);

 mutex_unlock(&display->backlight.lock);
}

#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
static u32 intel_panel_get_backlight(struct intel_connector *connector)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 val = 0;

 mutex_lock(&display->backlight.lock);

 if (panel->backlight.enabled)
  val = panel->backlight.funcs->get(connector, intel_connector_get_pipe(connector));

 mutex_unlock(&display->backlight.lock);

 drm_dbg_kms(display->drm, "get backlight PWM = %d\n", val);
 return val;
}

/* Scale user_level in range [0..user_max] to [hw_min..hw_max]. */
static u32 scale_user_to_hw(struct intel_connector *connector,
       u32 user_level, u32 user_max)
{
 struct intel_panel *panel = &connector->panel;

 return scale(user_level, 0, user_max,
       panel->backlight.min, panel->backlight.max);
}

/* set backlight brightness to level in range [0..max], scaling wrt hw min */
static void intel_panel_set_backlight(const struct drm_connector_state *conn_state,
          u32 user_level, u32 user_max)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 hw_level;

 if (!panel->backlight.present)
  return;

 mutex_lock(&display->backlight.lock);

 drm_WARN_ON(display->drm, panel->backlight.max == 0);

 hw_level = scale_user_to_hw(connector, user_level, user_max);
 panel->backlight.level = hw_level;

 if (panel->backlight.enabled)
  intel_panel_actually_set_backlight(conn_state, hw_level);

 mutex_unlock(&display->backlight.lock);
}

static int intel_backlight_device_update_status(struct backlight_device *bd)
{
 struct intel_connector *connector = bl_get_data(bd);
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 drm_modeset_lock(&display->drm->mode_config.connection_mutex, NULL);

 drm_dbg_kms(display->drm, "updating intel_backlight, brightness=%d/%d\n",
      bd->props.brightness, bd->props.max_brightness);
 intel_panel_set_backlight(connector->base.state, bd->props.brightness,
      bd->props.max_brightness);

 /*
 * Allow flipping bl_power as a sub-state of enabled. Sadly the
 * backlight class device does not make it easy to differentiate
 * between callbacks for brightness and bl_power, so our backlight_power
 * callback needs to take this into account.
 */
 if (panel->backlight.enabled) {
  if (panel->backlight.power) {
   bool enable = bd->props.power == BACKLIGHT_POWER_ON &&
    bd->props.brightness != 0;
   panel->backlight.power(connector, enable);
  }
 } else {
  bd->props.power = BACKLIGHT_POWER_OFF;
 }

 drm_modeset_unlock(&display->drm->mode_config.connection_mutex);

 return 0;
}

static int intel_backlight_device_get_brightness(struct backlight_device *bd)
{
 struct intel_connector *connector = bl_get_data(bd);
 struct intel_display *display = to_intel_display(connector);
 int ret = 0;

 with_intel_display_rpm(display) {
  u32 hw_level;

  drm_modeset_lock(&display->drm->mode_config.connection_mutex, NULL);

  hw_level = intel_panel_get_backlight(connector);
  ret = scale_hw_to_user(connector,
           hw_level, bd->props.max_brightness);

  drm_modeset_unlock(&display->drm->mode_config.connection_mutex);
 }

 return ret;
}

static const struct backlight_ops intel_backlight_device_ops = {
 .update_status = intel_backlight_device_update_status,
 .get_brightness = intel_backlight_device_get_brightness,
};

int intel_backlight_device_register(struct intel_connector *connector)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 struct backlight_properties props;
 struct backlight_device *bd;
 const char *name;
 int ret = 0;

 if (WARN_ON(panel->backlight.device))
  return -ENODEV;

 if (!panel->backlight.present)
  return 0;

 WARN_ON(panel->backlight.max == 0);

 if (!acpi_video_backlight_use_native()) {
  drm_info(display->drm,
    "Skipping intel_backlight registration\n");
  return 0;
 }

 memset(&props, 0, sizeof(props));
 props.type = BACKLIGHT_RAW;

 /*
 * Note: Everything should work even if the backlight device max
 * presented to the userspace is arbitrarily chosen.
 */
 props.max_brightness = panel->backlight.max;
 props.brightness = scale_hw_to_user(connector,
         panel->backlight.level,
         props.max_brightness);

 if (panel->backlight.enabled)
  props.power = BACKLIGHT_POWER_ON;
 else
  props.power = BACKLIGHT_POWER_OFF;

 name = kstrdup("intel_backlight", GFP_KERNEL);
 if (!name)
  return -ENOMEM;

 bd = backlight_device_get_by_name(name);
 if (bd) {
  put_device(&bd->dev);
  /*
 * Using the same name independent of the drm device or connector
 * prevents registration of multiple backlight devices in the
 * driver. However, we need to use the default name for backward
 * compatibility. Use unique names for subsequent backlight devices as a
 * fallback when the default name already exists.
 */
  kfree(name);
  name = kasprintf(GFP_KERNEL, "card%d-%s-backlight",
     display->drm->primary->index,
     connector->base.name);
  if (!name)
   return -ENOMEM;
 }
 bd = backlight_device_register(name, connector->base.kdev, connector,
           &intel_backlight_device_ops, &props);

 if (IS_ERR(bd)) {
  drm_err(display->drm,
   "[CONNECTOR:%d:%s] backlight device %s register failed: %ld\n",
   connector->base.base.id, connector->base.name, name, PTR_ERR(bd));
  ret = PTR_ERR(bd);
  goto out;
 }

 panel->backlight.device = bd;

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] backlight device %s registered\n",
      connector->base.base.id, connector->base.name, name);

out:
 kfree(name);

 return ret;
}

void intel_backlight_device_unregister(struct intel_connector *connector)
{
 struct intel_panel *panel = &connector->panel;

 if (panel->backlight.device) {
  backlight_device_unregister(panel->backlight.device);
  panel->backlight.device = NULL;
 }
}
#endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */

/*
 * CNP: PWM clock frequency is 19.2 MHz or 24 MHz.
 *      PWM increment = 1
 */
static u32 cnp_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
 struct intel_display *display = to_intel_display(connector);

 return DIV_ROUND_CLOSEST(KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq),
     pwm_freq_hz);
}

/*
 * BXT: PWM clock frequency = 19.2 MHz.
 */
static u32 bxt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
 return DIV_ROUND_CLOSEST(KHz(19200), pwm_freq_hz);
}

/*
 * SPT: This value represents the period of the PWM stream in clock periods
 * multiplied by 16 (default increment) or 128 (alternate increment selected in
 * SCHICKEN_1 bit 0). PWM clock is 24 MHz.
 */
static u32 spt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
 struct intel_panel *panel = &connector->panel;
 u32 mul;

 if (panel->backlight.alternate_pwm_increment)
  mul = 128;
 else
  mul = 16;

 return DIV_ROUND_CLOSEST(MHz(24), pwm_freq_hz * mul);
}

/*
 * LPT: This value represents the period of the PWM stream in clock periods
 * multiplied by 128 (default increment) or 16 (alternate increment, selected in
 * LPT SOUTH_CHICKEN2 register bit 5).
 */
static u32 lpt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 mul, clock;

 if (panel->backlight.alternate_pwm_increment)
  mul = 16;
 else
  mul = 128;

 if (HAS_PCH_LPT_H(display))
  clock = MHz(135); /* LPT:H */
 else
  clock = MHz(24); /* LPT:LP */

 return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * mul);
}

/*
 * ILK/SNB/IVB: This value represents the period of the PWM stream in PCH
 * display raw clocks multiplied by 128.
 */
static u32 pch_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
 struct intel_display *display = to_intel_display(connector);

 return DIV_ROUND_CLOSEST(KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq),
     pwm_freq_hz * 128);
}

/*
 * Gen2: This field determines the number of time base events (display core
 * clock frequency/32) in total for a complete cycle of modulated backlight
 * control.
 *
 * Gen3: A time base event equals the display core clock ([DevPNV] HRAW clock)
 * divided by 32.
 */
static u32 i9xx_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
 struct intel_display *display = to_intel_display(connector);
 int clock;

 if (display->platform.pineview)
  clock = KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq);
 else
  clock = KHz(display->cdclk.hw.cdclk);

 return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * 32);
}

/*
 * Gen4: This value represents the period of the PWM stream in display core
 * clocks ([DevCTG] HRAW clocks) multiplied by 128.
 *
 */
static u32 i965_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
 struct intel_display *display = to_intel_display(connector);
 int clock;

 if (display->platform.g4x)
  clock = KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq);
 else
  clock = KHz(display->cdclk.hw.cdclk);

 return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * 128);
}

/*
 * VLV: This value represents the period of the PWM stream in display core
 * clocks ([DevCTG] 200MHz HRAW clocks) multiplied by 128 or 25MHz S0IX clocks
 * multiplied by 16. CHV uses a 19.2MHz S0IX clock.
 */
static u32 vlv_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
 struct intel_display *display = to_intel_display(connector);
 int mul, clock;

 if ((intel_de_read(display, CBR1_VLV) & CBR_PWM_CLOCK_MUX_SELECT) == 0) {
  if (display->platform.cherryview)
   clock = KHz(19200);
  else
   clock = MHz(25);
  mul = 16;
 } else {
  clock = KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq);
  mul = 128;
 }

 return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * mul);
}

static u16 get_vbt_pwm_freq(struct intel_connector *connector)
{
 struct intel_display *display = to_intel_display(connector);
 u16 pwm_freq_hz = connector->panel.vbt.backlight.pwm_freq_hz;

 if (pwm_freq_hz) {
  drm_dbg_kms(display->drm,
       "VBT defined backlight frequency %u Hz\n",
       pwm_freq_hz);
 } else {
  pwm_freq_hz = 200;
  drm_dbg_kms(display->drm,
       "default backlight frequency %u Hz\n",
       pwm_freq_hz);
 }

 return pwm_freq_hz;
}

static u32 get_backlight_max_vbt(struct intel_connector *connector)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u16 pwm_freq_hz = get_vbt_pwm_freq(connector);
 u32 pwm;

 if (!panel->backlight.pwm_funcs->hz_to_pwm) {
  drm_dbg_kms(display->drm,
       "backlight frequency conversion not supported\n");
  return 0;
 }

 pwm = panel->backlight.pwm_funcs->hz_to_pwm(connector, pwm_freq_hz);
 if (!pwm) {
  drm_dbg_kms(display->drm,
       "backlight frequency conversion failed\n");
  return 0;
 }

 return pwm;
}

/*
 * Note: The setup hooks can't assume pipe is set!
 */
static u32 get_backlight_min_vbt(struct intel_connector *connector)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 int min;

 drm_WARN_ON(display->drm, panel->backlight.pwm_level_max == 0);

 /*
 * XXX: If the vbt value is 255, it makes min equal to max, which leads
 * to problems. There are such machines out there. Either our
 * interpretation is wrong or the vbt has bogus data. Or both. Safeguard
 * against this by letting the minimum be at most (arbitrarily chosen)
 * 25% of the max.
 */
 min = clamp_t(int, connector->panel.vbt.backlight.min_brightness, 0, 64);
 if (min != connector->panel.vbt.backlight.min_brightness) {
  drm_dbg_kms(display->drm,
       "clamping VBT min backlight %d/255 to %d/255\n",
       connector->panel.vbt.backlight.min_brightness, min);
 }

 /* vbt value is a coefficient in range [0..255] */
 return scale(min, 0, 255, 0, panel->backlight.pwm_level_max);
}

static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 cpu_ctl2, pch_ctl1, pch_ctl2, val;
 bool alt, cpu_mode;

 if (HAS_PCH_LPT(display))
  alt = intel_de_read(display, SOUTH_CHICKEN2) & LPT_PWM_GRANULARITY;
 else
  alt = intel_de_read(display, SOUTH_CHICKEN1) & SPT_PWM_GRANULARITY;
 panel->backlight.alternate_pwm_increment = alt;

 pch_ctl1 = intel_de_read(display, BLC_PWM_PCH_CTL1);
 panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;

 pch_ctl2 = intel_de_read(display, BLC_PWM_PCH_CTL2);
 panel->backlight.pwm_level_max = pch_ctl2 >> 16;

 cpu_ctl2 = intel_de_read(display, BLC_PWM_CPU_CTL2);

 if (!panel->backlight.pwm_level_max)
  panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);

 if (!panel->backlight.pwm_level_max)
  return -ENODEV;

 panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);

 panel->backlight.pwm_enabled = pch_ctl1 & BLM_PCH_PWM_ENABLE;

 cpu_mode = panel->backlight.pwm_enabled && HAS_PCH_LPT(display) &&
     !(pch_ctl1 & BLM_PCH_OVERRIDE_ENABLE) &&
     (cpu_ctl2 & BLM_PWM_ENABLE);

 if (cpu_mode) {
  val = pch_get_backlight(connector, unused);

  drm_dbg_kms(display->drm,
       "CPU backlight register was enabled, switching to PCH override\n");

  /* Write converted CPU PWM value to PCH override register */
  lpt_set_backlight(connector->base.state, val);
  intel_de_write(display, BLC_PWM_PCH_CTL1,
          pch_ctl1 | BLM_PCH_OVERRIDE_ENABLE);

  intel_de_write(display, BLC_PWM_CPU_CTL2,
          cpu_ctl2 & ~BLM_PWM_ENABLE);
 }

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control\n",
      connector->base.base.id, connector->base.name);

 return 0;
}

static int pch_setup_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 cpu_ctl2, pch_ctl1, pch_ctl2;

 pch_ctl1 = intel_de_read(display, BLC_PWM_PCH_CTL1);
 panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;

 pch_ctl2 = intel_de_read(display, BLC_PWM_PCH_CTL2);
 panel->backlight.pwm_level_max = pch_ctl2 >> 16;

 if (!panel->backlight.pwm_level_max)
  panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);

 if (!panel->backlight.pwm_level_max)
  return -ENODEV;

 panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);

 cpu_ctl2 = intel_de_read(display, BLC_PWM_CPU_CTL2);
 panel->backlight.pwm_enabled = (cpu_ctl2 & BLM_PWM_ENABLE) &&
  (pch_ctl1 & BLM_PCH_PWM_ENABLE);

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control\n",
      connector->base.base.id, connector->base.name);

 return 0;
}

static int i9xx_setup_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 ctl, val;

 ctl = intel_de_read(display, BLC_PWM_CTL);

 if (DISPLAY_VER(display) == 2 || display->platform.i915gm || display->platform.i945gm)
  panel->backlight.combination_mode = ctl & BLM_LEGACY_MODE;

 if (display->platform.pineview)
  panel->backlight.active_low_pwm = ctl & BLM_POLARITY_PNV;

 panel->backlight.pwm_level_max = ctl >> 17;

 if (!panel->backlight.pwm_level_max) {
  panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
  panel->backlight.pwm_level_max >>= 1;
 }

 if (!panel->backlight.pwm_level_max)
  return -ENODEV;

 if (panel->backlight.combination_mode)
  panel->backlight.pwm_level_max *= 0xff;

 panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);

 val = i9xx_get_backlight(connector, unused);
 val = intel_backlight_invert_pwm_level(connector, val);
 val = clamp(val, panel->backlight.pwm_level_min, panel->backlight.pwm_level_max);

 panel->backlight.pwm_enabled = val != 0;

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] Using native PWM for backlight control\n",
      connector->base.base.id, connector->base.name);

 return 0;
}

static int i965_setup_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 ctl, ctl2;

 ctl2 = intel_de_read(display, BLC_PWM_CTL2);
 panel->backlight.combination_mode = ctl2 & BLM_COMBINATION_MODE;
 panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;

 ctl = intel_de_read(display, BLC_PWM_CTL);
 panel->backlight.pwm_level_max = ctl >> 16;

 if (!panel->backlight.pwm_level_max)
  panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);

 if (!panel->backlight.pwm_level_max)
  return -ENODEV;

 if (panel->backlight.combination_mode)
  panel->backlight.pwm_level_max *= 0xff;

 panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);

 panel->backlight.pwm_enabled = ctl2 & BLM_PWM_ENABLE;

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] Using native PWM for backlight control\n",
      connector->base.base.id, connector->base.name);

 return 0;
}

static int vlv_setup_backlight(struct intel_connector *connector, enum pipe pipe)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 ctl, ctl2;

 if (drm_WARN_ON(display->drm, pipe != PIPE_A && pipe != PIPE_B))
  return -ENODEV;

 ctl2 = intel_de_read(display, VLV_BLC_PWM_CTL2(pipe));
 panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;

 ctl = intel_de_read(display, VLV_BLC_PWM_CTL(pipe));
 panel->backlight.pwm_level_max = ctl >> 16;

 if (!panel->backlight.pwm_level_max)
  panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);

 if (!panel->backlight.pwm_level_max)
  return -ENODEV;

 panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);

 panel->backlight.pwm_enabled = ctl2 & BLM_PWM_ENABLE;

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] Using native PWM for backlight control (on pipe %c)\n",
      connector->base.base.id, connector->base.name, pipe_name(pipe));

 return 0;
}

static int
bxt_setup_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 pwm_ctl, val;

 panel->backlight.controller = connector->panel.vbt.backlight.controller;

 pwm_ctl = intel_de_read(display,
    BXT_BLC_PWM_CTL(panel->backlight.controller));

 /* Controller 1 uses the utility pin. */
 if (panel->backlight.controller == 1) {
  val = intel_de_read(display, UTIL_PIN_CTL);
  panel->backlight.util_pin_active_low =
     val & UTIL_PIN_POLARITY;
 }

 panel->backlight.active_low_pwm = pwm_ctl & BXT_BLC_PWM_POLARITY;
 panel->backlight.pwm_level_max =
  intel_de_read(display, BXT_BLC_PWM_FREQ(panel->backlight.controller));

 if (!panel->backlight.pwm_level_max)
  panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);

 if (!panel->backlight.pwm_level_max)
  return -ENODEV;

 panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);

 panel->backlight.pwm_enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] Using native PWM for backlight control (controller=%d)\n",
      connector->base.base.id, connector->base.name,
      panel->backlight.controller);

 return 0;
}

static int cnp_num_backlight_controllers(struct intel_display *display)
{
 if (INTEL_PCH_TYPE(display) >= PCH_MTL)
  return 2;

 if (INTEL_PCH_TYPE(display) >= PCH_DG1)
  return 1;

 if (INTEL_PCH_TYPE(display) >= PCH_ICP)
  return 2;

 return 1;
}

static bool cnp_backlight_controller_is_valid(struct intel_display *display, int controller)
{
 if (controller < 0 || controller >= cnp_num_backlight_controllers(display))
  return false;

 if (controller == 1 &&
     INTEL_PCH_TYPE(display) >= PCH_ICP &&
     INTEL_PCH_TYPE(display) <= PCH_ADP)
  return intel_de_read(display, SOUTH_CHICKEN1) & ICP_SECOND_PPS_IO_SELECT;

 return true;
}

static int
cnp_setup_backlight(struct intel_connector *connector, enum pipe unused)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 u32 pwm_ctl;

 /*
 * CNP has the BXT implementation of backlight, but with only one
 * controller. ICP+ can have two controllers, depending on pin muxing.
 */
 panel->backlight.controller = connector->panel.vbt.backlight.controller;
 if (!cnp_backlight_controller_is_valid(display, panel->backlight.controller)) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] Invalid backlight controller %d, assuming 0\n",
       connector->base.base.id, connector->base.name,
       panel->backlight.controller);
  panel->backlight.controller = 0;
 }

 pwm_ctl = intel_de_read(display,
    BXT_BLC_PWM_CTL(panel->backlight.controller));

 panel->backlight.active_low_pwm = pwm_ctl & BXT_BLC_PWM_POLARITY;
 panel->backlight.pwm_level_max =
  intel_de_read(display, BXT_BLC_PWM_FREQ(panel->backlight.controller));

 if (!panel->backlight.pwm_level_max)
  panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);

 if (!panel->backlight.pwm_level_max)
  return -ENODEV;

 panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);

 panel->backlight.pwm_enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control (controller=%d)\n",
      connector->base.base.id, connector->base.name,
      panel->backlight.controller);

 return 0;
}

static int ext_pwm_setup_backlight(struct intel_connector *connector,
       enum pipe pipe)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 const char *desc;
 u32 level;

 /* Get the right PWM chip for DSI backlight according to VBT */
 if (connector->panel.vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) {
  panel->backlight.pwm = pwm_get(display->drm->dev,
            "pwm_pmic_backlight");
  desc = "PMIC";
 } else {
  panel->backlight.pwm = pwm_get(display->drm->dev,
            "pwm_soc_backlight");
  desc = "SoC";
 }

 if (IS_ERR(panel->backlight.pwm)) {
  drm_err(display->drm,
   "[CONNECTOR:%d:%s] Failed to get the %s PWM chip\n",
   connector->base.base.id, connector->base.name, desc);
  panel->backlight.pwm = NULL;
  return -ENODEV;
 }

 panel->backlight.pwm_level_max = 100; /* 100% */
 panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);

 if (pwm_is_enabled(panel->backlight.pwm)) {
  /* PWM is already enabled, use existing settings */
  pwm_get_state(panel->backlight.pwm, &panel->backlight.pwm_state);

  level = pwm_get_relative_duty_cycle(&panel->backlight.pwm_state,
          100);
  level = intel_backlight_invert_pwm_level(connector, level);
  panel->backlight.pwm_enabled = true;

  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] PWM already enabled at freq %ld, VBT freq %d, level %d\n",
       connector->base.base.id, connector->base.name,
       NSEC_PER_SEC / (unsigned long)panel->backlight.pwm_state.period,
       get_vbt_pwm_freq(connector), level);
 } else {
  /* Set period from VBT frequency, leave other settings at 0. */
  panel->backlight.pwm_state.period =
   NSEC_PER_SEC / get_vbt_pwm_freq(connector);
 }

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] Using %s PWM for backlight control\n",
      connector->base.base.id, connector->base.name, desc);

 return 0;
}

static void intel_pwm_set_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_panel *panel = &connector->panel;

 panel->backlight.pwm_funcs->set(conn_state,
     intel_backlight_invert_pwm_level(connector, level));
}

static u32 intel_pwm_get_backlight(struct intel_connector *connector, enum pipe pipe)
{
 struct intel_panel *panel = &connector->panel;

 return intel_backlight_invert_pwm_level(connector,
         panel->backlight.pwm_funcs->get(connector, pipe));
}

static void intel_pwm_enable_backlight(const struct intel_crtc_state *crtc_state,
           const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_panel *panel = &connector->panel;

 panel->backlight.pwm_funcs->enable(crtc_state, conn_state,
        intel_backlight_invert_pwm_level(connector, level));
}

static void intel_pwm_disable_backlight(const struct drm_connector_state *conn_state, u32 level)
{
 struct intel_connector *connector = to_intel_connector(conn_state->connector);
 struct intel_panel *panel = &connector->panel;

 panel->backlight.pwm_funcs->disable(conn_state,
         intel_backlight_invert_pwm_level(connector, level));
}

static int intel_pwm_setup_backlight(struct intel_connector *connector, enum pipe pipe)
{
 struct intel_panel *panel = &connector->panel;
 int ret;

 ret = panel->backlight.pwm_funcs->setup(connector, pipe);
 if (ret < 0)
  return ret;

 panel->backlight.min = panel->backlight.pwm_level_min;
 panel->backlight.max = panel->backlight.pwm_level_max;
 panel->backlight.level = intel_pwm_get_backlight(connector, pipe);
 panel->backlight.enabled = panel->backlight.pwm_enabled;

 return 0;
}

void intel_backlight_update(struct intel_atomic_state *state,
       struct intel_encoder *encoder,
       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_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;

 if (!panel->backlight.present)
  return;

 mutex_lock(&display->backlight.lock);
 if (!panel->backlight.enabled)
  __intel_backlight_enable(crtc_state, conn_state);

 mutex_unlock(&display->backlight.lock);
}

int intel_backlight_setup(struct intel_connector *connector, enum pipe pipe)
{
 struct intel_display *display = to_intel_display(connector);
 struct intel_panel *panel = &connector->panel;
 int ret;

 if (!connector->panel.vbt.backlight.present) {
  if (intel_has_quirk(display, QUIRK_BACKLIGHT_PRESENT)) {
   drm_dbg_kms(display->drm,
        "[CONNECTOR:%d:%s] no backlight present per VBT, but present per quirk\n",
        connector->base.base.id, connector->base.name);
  } else {
   drm_dbg_kms(display->drm,
        "[CONNECTOR:%d:%s] no backlight present per VBT\n",
        connector->base.base.id, connector->base.name);
   return 0;
  }
 }

 /* ensure intel_panel has been initialized first */
 if (drm_WARN_ON(display->drm, !panel->backlight.funcs))
  return -ENODEV;

 /* set level and max in panel struct */
 mutex_lock(&display->backlight.lock);
 ret = panel->backlight.funcs->setup(connector, pipe);
 mutex_unlock(&display->backlight.lock);

 if (ret) {
  drm_dbg_kms(display->drm,
       "[CONNECTOR:%d:%s] failed to setup backlight\n",
       connector->base.base.id, connector->base.name);
  return ret;
 }

 panel->backlight.present = true;

 drm_dbg_kms(display->drm,
      "[CONNECTOR:%d:%s] backlight initialized, %s, brightness %u/%u\n",
      connector->base.base.id, connector->base.name,
      str_enabled_disabled(panel->backlight.enabled),
      panel->backlight.level, panel->backlight.max);

 return 0;
}

void intel_backlight_destroy(struct intel_panel *panel)
{
 /* dispose of the pwm */
 if (panel->backlight.pwm)
  pwm_put(panel->backlight.pwm);

 panel->backlight.present = false;
}

static const struct intel_panel_bl_funcs bxt_pwm_funcs = {
 .setup = bxt_setup_backlight,
 .enable = bxt_enable_backlight,
 .disable = bxt_disable_backlight,
 .set = bxt_set_backlight,
 .get = bxt_get_backlight,
 .hz_to_pwm = bxt_hz_to_pwm,
};

static const struct intel_panel_bl_funcs cnp_pwm_funcs = {
 .setup = cnp_setup_backlight,
 .enable = cnp_enable_backlight,
 .disable = cnp_disable_backlight,
 .set = bxt_set_backlight,
 .get = bxt_get_backlight,
 .hz_to_pwm = cnp_hz_to_pwm,
};

static const struct intel_panel_bl_funcs lpt_pwm_funcs = {
 .setup = lpt_setup_backlight,
 .enable = lpt_enable_backlight,
 .disable = lpt_disable_backlight,
 .set = lpt_set_backlight,
 .get = lpt_get_backlight,
 .hz_to_pwm = lpt_hz_to_pwm,
};

static const struct intel_panel_bl_funcs spt_pwm_funcs = {
 .setup = lpt_setup_backlight,
 .enable = lpt_enable_backlight,
 .disable = lpt_disable_backlight,
 .set = lpt_set_backlight,
 .get = lpt_get_backlight,
 .hz_to_pwm = spt_hz_to_pwm,
};

static const struct intel_panel_bl_funcs pch_pwm_funcs = {
 .setup = pch_setup_backlight,
 .enable = pch_enable_backlight,
 .disable = pch_disable_backlight,
 .set = pch_set_backlight,
 .get = pch_get_backlight,
 .hz_to_pwm = pch_hz_to_pwm,
};

static const struct intel_panel_bl_funcs ext_pwm_funcs = {
 .setup = ext_pwm_setup_backlight,
 .enable = ext_pwm_enable_backlight,
 .disable = ext_pwm_disable_backlight,
 .set = ext_pwm_set_backlight,
 .get = ext_pwm_get_backlight,
};

static const struct intel_panel_bl_funcs vlv_pwm_funcs = {
 .setup = vlv_setup_backlight,
 .enable = vlv_enable_backlight,
 .disable = vlv_disable_backlight,
 .set = vlv_set_backlight,
 .get = vlv_get_backlight,
 .hz_to_pwm = vlv_hz_to_pwm,
};

static const struct intel_panel_bl_funcs i965_pwm_funcs = {
 .setup = i965_setup_backlight,
 .enable = i965_enable_backlight,
 .disable = i965_disable_backlight,
 .set = i9xx_set_backlight,
 .get = i9xx_get_backlight,
 .hz_to_pwm = i965_hz_to_pwm,
};

static const struct intel_panel_bl_funcs i9xx_pwm_funcs = {
 .setup = i9xx_setup_backlight,
 .enable = i9xx_enable_backlight,
 .disable = i9xx_disable_backlight,
 .set = i9xx_set_backlight,
 .get = i9xx_get_backlight,
 .hz_to_pwm = i9xx_hz_to_pwm,
};

static const struct intel_panel_bl_funcs pwm_bl_funcs = {
 .setup = intel_pwm_setup_backlight,
 .enable = intel_pwm_enable_backlight,
 .disable = intel_pwm_disable_backlight,
 .set = intel_pwm_set_backlight,
 .get = intel_pwm_get_backlight,
};

/* Set up chip specific backlight functions */
void intel_backlight_init_funcs(struct intel_panel *panel)
{
 struct intel_connector *connector =
  container_of(panel, struct intel_connector, panel);
 struct intel_display *display = to_intel_display(connector);

 if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI &&
     intel_dsi_dcs_init_backlight_funcs(connector) == 0)
  return;

 if (display->platform.geminilake || display->platform.broxton) {
  panel->backlight.pwm_funcs = &bxt_pwm_funcs;
 } else if (INTEL_PCH_TYPE(display) >= PCH_CNP) {
  panel->backlight.pwm_funcs = &cnp_pwm_funcs;
 } else if (INTEL_PCH_TYPE(display) >= PCH_LPT_H) {
  if (HAS_PCH_LPT(display))
   panel->backlight.pwm_funcs = &lpt_pwm_funcs;
  else
   panel->backlight.pwm_funcs = &spt_pwm_funcs;
 } else if (HAS_PCH_SPLIT(display)) {
  panel->backlight.pwm_funcs = &pch_pwm_funcs;
 } else if (display->platform.valleyview || display->platform.cherryview) {
  if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI) {
   panel->backlight.pwm_funcs = &ext_pwm_funcs;
  } else {
   panel->backlight.pwm_funcs = &vlv_pwm_funcs;
  }
 } else if (DISPLAY_VER(display) == 4) {
  panel->backlight.pwm_funcs = &i965_pwm_funcs;
 } else {
  panel->backlight.pwm_funcs = &i9xx_pwm_funcs;
 }

 if (connector->base.connector_type == DRM_MODE_CONNECTOR_eDP) {
  if (intel_dp_aux_init_backlight_funcs(connector) == 0)
   return;

  if (!intel_has_quirk(display, QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK))
   connector->panel.backlight.power = intel_pps_backlight_power;
 }

 /* We're using a standard PWM backlight interface */
 panel->backlight.funcs = &pwm_bl_funcs;
}