From 9aba9d3a2ca42572c9c196e8be6cab59b7c078b6 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Thu, 3 May 2012 15:06:05 +0100 Subject: [PATCH] gma500: implement backlight functionality for Cedartrail devices Basically a straight cut/paste from the reference driver code then cleaned up a spot. Signed-off-by: Alan Cox Signed-off-by: Dave Airlie --- drivers/gpu/drm/gma500/cdv_device.c | 115 ++++++++++++++++-------------------- 1 file changed, 52 insertions(+), 63 deletions(-) diff --git a/drivers/gpu/drm/gma500/cdv_device.c b/drivers/gpu/drm/gma500/cdv_device.c index 62f9b73..726bfb7 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)); @@ -162,14 +155,9 @@ 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.max_brightness = 100; + cdv_backlight_device->props.brightness = + cdv_get_brightness(cdv_backlight_device); + cdv_backlight_device->props.max_brightness = cdv_get_max_brightness; backlight_update_status(cdv_backlight_device); dev_priv->backlight_device = cdv_backlight_device; return 0; @@ -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); } -- 2.7.4