[PATCH 6/6] drm/i915: Use DIV_ROUND_CLOSEST for PWM calculations

ville.syrjala
2016-03-02T15:22:38Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Supposedly we would want to get the PWM output as close as possible to
the target, so let's round to closest.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/intel_panel.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 5cf377507162..0fe059bc7d80 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -1240,7 +1240,7 @@ static void intel_backlight_device_unregister(struct intel_connector *connector)
*/
static u32 bxt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
- return KHz(19200) / pwm_freq_hz;
+ return DIV_ROUND_CLOSEST(KHz(19200), pwm_freq_hz);
}

/*
@@ -1258,7 +1258,7 @@ static u32 spt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
else
mul = 16;

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

/*
@@ -1281,7 +1281,7 @@ static u32 lpt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
else
clock = MHz(24); /* LPT:LP */

- return clock / (pwm_freq_hz * mul);
+ return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * mul);
}

/*
@@ -1292,7 +1292,7 @@ static u32 pch_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
{
struct drm_i915_private *dev_priv = to_i915(connector->base.dev);

- return KHz(dev_priv->rawclk_freq) / (pwm_freq_hz * 128);
+ return DIV_ROUND_CLOSEST(KHz(dev_priv->rawclk_freq), pwm_freq_hz * 128);
}

/*
@@ -1313,7 +1313,7 @@ static u32 i9xx_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
else
clock = KHz(dev_priv->cdclk_freq);

- return clock / (pwm_freq_hz * 32);
+ return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * 32);
}

/*
@@ -1332,7 +1332,7 @@ static u32 i965_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
else
clock = KHz(dev_priv->cdclk_freq);

- return clock / (pwm_freq_hz * 128);
+ return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * 128);
}

/*
@@ -1356,7 +1356,7 @@ static u32 vlv_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
mul = 128;
}

- return clock / (pwm_freq_hz * mul);
+ return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * mul);
}

static u32 get_backlight_max_vbt(struct intel_connector *connector)
--
2.4.10