Commit 37f2248e authored by Ville Syrjälä's avatar Ville Syrjälä

drm/i915: Use DIV_ROUND_CLOSEST for PWM calculations

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: default avatarJani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1456932138-14004-7-git-send-email-ville.syrjala@linux.intel.comReviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
parent a457f54b
...@@ -1240,7 +1240,7 @@ static void intel_backlight_device_unregister(struct intel_connector *connector) ...@@ -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) 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) ...@@ -1258,7 +1258,7 @@ static u32 spt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
else else
mul = 16; 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) ...@@ -1281,7 +1281,7 @@ static u32 lpt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
else else
clock = MHz(24); /* LPT:LP */ 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) ...@@ -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); 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) ...@@ -1313,7 +1313,7 @@ static u32 i9xx_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
else else
clock = KHz(dev_priv->cdclk_freq); 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) ...@@ -1332,7 +1332,7 @@ static u32 i965_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
else else
clock = KHz(dev_priv->cdclk_freq); 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) ...@@ -1356,7 +1356,7 @@ static u32 vlv_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
mul = 128; 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) static u32 get_backlight_max_vbt(struct intel_connector *connector)
......
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