From b222f2673354c65e178cbcba610e7883a05f5bf3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sat, 11 Sep 2010 21:48:25 +0100 Subject: [PATCH] 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 --- drivers/gpu/drm/i915/intel_i2c.c | 34 +++++++++++++++------------------- 1 file 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; -- 2.11.0