[PATCH 4/6] gma500: implement backlight functionality for Cedartrail devices
Alan Cox
alan at lxorguk.ukuu.org.uk
Tue Apr 24 08:47:30 PDT 2012
From: Alan Cox <alan at linux.intel.com>
Basically a straight cut/paste from the reference driver code then
cleaned up a spot.
Signed-off-by: Alan Cox <alan at linux.intel.com>
---
drivers/gpu/drm/gma500/cdv_device.c | 113 ++++++++++++++++-------------------
1 files changed, 51 insertions(+), 62 deletions(-)
diff --git a/drivers/gpu/drm/gma500/cdv_device.c b/drivers/gpu/drm/gma500/cdv_device.c
index 5cc06a8..292bcec 100644
--- a/drivers/gpu/drm/gma500/cdv_device.c
+++ b/drivers/gpu/drm/gma500/cdv_device.c
@@ -57,8 +57,7 @@ static int cdv_output_init(struct drm_device *dev)
cdv_intel_crt_init(dev, &dev_priv->mode_dev);
cdv_intel_lvds_init(dev, &dev_priv->mode_dev);
- /* These bits indicate HDMI not SDVO on CDV, but we don't yet support
- the HDMI interface */
+ /* These bits indicate HDMI not SDVO on CDV */
if (REG_READ(SDVOB) & SDVO_DETECTED)
cdv_hdmi_init(dev, &dev_priv->mode_dev, SDVOB);
if (REG_READ(SDVOC) & SDVO_DETECTED)
@@ -69,76 +68,71 @@ static int cdv_output_init(struct drm_device *dev)
#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
/*
- * Poulsbo Backlight Interfaces
+ * Cedartrail Backlght Interfaces
*/
-#define BLC_PWM_PRECISION_FACTOR 100 /* 10000000 */
-#define BLC_PWM_FREQ_CALC_CONSTANT 32
-#define MHz 1000000
-
-#define PSB_BLC_PWM_PRECISION_FACTOR 10
-#define PSB_BLC_MAX_PWM_REG_FREQ 0xFFFE
-#define PSB_BLC_MIN_PWM_REG_FREQ 0x2
-
-#define PSB_BACKLIGHT_PWM_POLARITY_BIT_CLEAR (0xFFFE)
-#define PSB_BACKLIGHT_PWM_CTL_SHIFT (16)
-
-static int cdv_brightness;
static struct backlight_device *cdv_backlight_device;
-static int cdv_get_brightness(struct backlight_device *bd)
+static int cdv_backlight_combination_mode(struct drm_device *dev)
{
- /* return locally cached var instead of HW read (due to DPST etc.) */
- /* FIXME: ideally return actual value in case firmware fiddled with
- it */
- return cdv_brightness;
+ return REG_READ(BLC_PWM_CTL2) & PWM_LEGACY_MODE;
}
-
-static int cdv_backlight_setup(struct drm_device *dev)
+static int cdv_get_brightness(struct backlight_device *bd)
{
- struct drm_psb_private *dev_priv = dev->dev_private;
- unsigned long core_clock;
- /* u32 bl_max_freq; */
- /* unsigned long value; */
- u16 bl_max_freq;
- uint32_t value;
- uint32_t blc_pwm_precision_factor;
-
- /* get bl_max_freq and pol from dev_priv*/
- if (!dev_priv->lvds_bl) {
- dev_err(dev->dev, "Has no valid LVDS backlight info\n");
- return -ENOENT;
- }
- bl_max_freq = dev_priv->lvds_bl->freq;
- blc_pwm_precision_factor = PSB_BLC_PWM_PRECISION_FACTOR;
+ struct drm_device *dev = bl_get_data(bd);
+ u32 val = REG_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
- core_clock = dev_priv->core_freq;
+ if (cdv_backlight_combination_mode(dev)) {
+ u8 lbpc;
- value = (core_clock * MHz) / BLC_PWM_FREQ_CALC_CONSTANT;
- value *= blc_pwm_precision_factor;
- value /= bl_max_freq;
- value /= blc_pwm_precision_factor;
+ val &= ~1;
+ pci_read_config_byte(dev->pdev, 0xF4, &lbpc);
+ val *= lbpc;
+ }
+ return val;
+}
- if (value > (unsigned long long)PSB_BLC_MAX_PWM_REG_FREQ ||
- value < (unsigned long long)PSB_BLC_MIN_PWM_REG_FREQ)
- return -ERANGE;
- else {
- /* FIXME */
+static u32 cdv_get_max_backlight(struct drm_device *dev)
+{
+ u32 max = REG_READ(BLC_PWM_CTL);
+
+ if (max == 0) {
+ DRM_DEBUG_KMS("LVDS Panel PWM value is 0!\n");
+ /* i915 does this, I believe which means that we should not
+ * smash PWM control as firmware will take control of it. */
+ return 1;
}
- return 0;
+
+ max >>= 16;
+ if (cdv_backlight_combination_mode(dev))
+ max *= 0xff;
+ return max;
}
static int cdv_set_brightness(struct backlight_device *bd)
{
+ struct drm_device *dev = bl_get_data(bd);
int level = bd->props.brightness;
+ u32 blc_pwm_ctl;
/* Percentage 1-100% being valid */
if (level < 1)
level = 1;
- /*cdv_intel_lvds_set_brightness(dev, level); FIXME */
- cdv_brightness = level;
+ if (cdv_backlight_combination_mode(dev)) {
+ u32 max = cdv_get_max_backlight(dev);
+ u8 lbpc;
+
+ lbpc = level * 0xfe / max + 1;
+ level /= lbpc;
+
+ pci_write_config_byte(dev->pdev, 0xF4, lbpc);
+ }
+
+ blc_pwm_ctl = REG_READ(BLC_PWM_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
+ REG_WRITE(BLC_PWM_CTL, (blc_pwm_ctl |
+ (level << BACKLIGHT_DUTY_CYCLE_SHIFT)));
return 0;
}
@@ -150,7 +144,6 @@ static const struct backlight_ops cdv_ops = {
static int cdv_backlight_init(struct drm_device *dev)
{
struct drm_psb_private *dev_priv = dev->dev_private;
- int ret;
struct backlight_properties props;
memset(&props, 0, sizeof(struct backlight_properties));
@@ -162,13 +155,8 @@ static int cdv_backlight_init(struct drm_device *dev)
if (IS_ERR(cdv_backlight_device))
return PTR_ERR(cdv_backlight_device);
- ret = cdv_backlight_setup(dev);
- if (ret < 0) {
- backlight_device_unregister(cdv_backlight_device);
- cdv_backlight_device = NULL;
- return ret;
- }
- cdv_backlight_device->props.brightness = 100;
+ cdv_backlight_device->props.brightness =
+ cdv_get_brightness(cdv_backlight_device);
cdv_backlight_device->props.max_brightness = 100;
backlight_update_status(cdv_backlight_device);
dev_priv->backlight_device = cdv_backlight_device;
@@ -244,11 +232,12 @@ static void cdv_init_pm(struct drm_device *dev)
static void cdv_errata(struct drm_device *dev)
{
/* Disable bonus launch.
- * CPU and GPU competes for memory and display misses updates and flickers.
- * Worst with dual core, dual displays.
+ * CPU and GPU competes for memory and display misses updates and
+ * flickers. Worst with dual core, dual displays.
*
- * Fixes were done to Win 7 gfx driver to disable a feature called Bonus
- * Launch to work around the issue, by degrading performance.
+ * Fixes were done to Win 7 gfx driver to disable a feature called
+ * Bonus Launch to work around the issue, by degrading
+ * performance.
*/
CDV_MSG_WRITE32(3, 0x30, 0x08027108);
}
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