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authorChris Wilson <chris@chris-wilson.co.uk>2010-09-11 21:48:25 +0100
committerChris Wilson <chris@chris-wilson.co.uk>2010-09-11 22:28:13 +0100
commitb222f2673354c65e178cbcba610e7883a05f5bf3 (patch)
tree044fb7ba6b3fae23fa50b44682d133291ccd4179 /drivers/gpu/drm/i915/intel_i2c.c
parentfe255d0028903f1132a3c1214edc91cf95b7cd98 (diff)
downloadlwn-b222f2673354c65e178cbcba610e7883a05f5bf3.tar.gz
lwn-b222f2673354c65e178cbcba610e7883a05f5bf3.zip
drm/i915/i2c: The bit-banging interface controls the delay, drop ours
Remove our redundant udelay() as the timings are already handled by the i2c-algo-bit controller. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_i2c.c')
-rw-r--r--drivers/gpu/drm/i915/intel_i2c.c34
1 files changed, 15 insertions, 19 deletions
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index c2649c7df14c..de03989d6df3 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -38,16 +38,18 @@
void intel_i2c_quirk_set(struct drm_device *dev, bool enable)
{
struct drm_i915_private *dev_priv = dev->dev_private;
+ u32 val;
/* When using bit bashing for I2C, this bit needs to be set to 1 */
if (!IS_PINEVIEW(dev))
return;
+
+ val = I915_READ(DSPCLK_GATE_D);
if (enable)
- I915_WRITE(DSPCLK_GATE_D,
- I915_READ(DSPCLK_GATE_D) | DPCUNIT_CLOCK_GATE_DISABLE);
+ val |= DPCUNIT_CLOCK_GATE_DISABLE;
else
- I915_WRITE(DSPCLK_GATE_D,
- I915_READ(DSPCLK_GATE_D) & (~DPCUNIT_CLOCK_GATE_DISABLE));
+ val &= ~DPCUNIT_CLOCK_GATE_DISABLE;
+ I915_WRITE(DSPCLK_GATE_D, val);
}
/*
@@ -60,20 +62,14 @@ static int get_clock(void *data)
{
struct intel_i2c_chan *chan = data;
struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
- u32 val;
-
- val = I915_READ(chan->reg);
- return ((val & GPIO_CLOCK_VAL_IN) != 0);
+ return (I915_READ(chan->reg) & GPIO_CLOCK_VAL_IN) != 0;
}
static int get_data(void *data)
{
struct intel_i2c_chan *chan = data;
struct drm_i915_private *dev_priv = chan->drm_dev->dev_private;
- u32 val;
-
- val = I915_READ(chan->reg);
- return ((val & GPIO_DATA_VAL_IN) != 0);
+ return (I915_READ(chan->reg) & GPIO_DATA_VAL_IN) != 0;
}
static void set_clock(void *data, int state_high)
@@ -94,7 +90,7 @@ static void set_clock(void *data, int state_high)
clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
GPIO_CLOCK_VAL_MASK;
I915_WRITE(chan->reg, reserved | clock_bits);
- udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
+ POSTING_READ(chan->reg);
}
static void set_data(void *data, int state_high)
@@ -116,7 +112,7 @@ static void set_data(void *data, int state_high)
GPIO_DATA_VAL_MASK;
I915_WRITE(chan->reg, reserved | data_bits);
- udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */
+ POSTING_READ(chan->reg);
}
/* Clears the GMBUS setup. Our driver doesn't make use of the GMBUS I2C
@@ -129,11 +125,10 @@ intel_i2c_reset_gmbus(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
- if (HAS_PCH_SPLIT(dev)) {
+ if (HAS_PCH_SPLIT(dev))
I915_WRITE(PCH_GMBUS0, 0);
- } else {
+ else
I915_WRITE(GMBUS0, 0);
- }
}
/**
@@ -177,7 +172,7 @@ struct i2c_adapter *intel_i2c_create(struct drm_device *dev, const u32 reg,
chan->algo.setscl = set_clock;
chan->algo.getsda = get_data;
chan->algo.getscl = get_clock;
- chan->algo.udelay = 20;
+ chan->algo.udelay = I2C_RISEFALL_TIME;
chan->algo.timeout = usecs_to_jiffies(2200);
chan->algo.data = chan;
@@ -191,9 +186,10 @@ struct i2c_adapter *intel_i2c_create(struct drm_device *dev, const u32 reg,
/* JJJ: raise SCL and SDA? */
intel_i2c_quirk_set(dev, true);
set_data(chan, 1);
+ udelay(I2C_RISEFALL_TIME);
set_clock(chan, 1);
+ udelay(I2C_RISEFALL_TIME);
intel_i2c_quirk_set(dev, false);
- udelay(20);
return &chan->adapter;