From 0ba0e9e1f173a59ba402a253d356612c821b7a14 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Tue, 7 Apr 2009 11:02:28 +0800 Subject: [PATCH] drm/i915: workaround IGD i2c bus issue in kernel side (v2) In IGD, DPCUNIT_CLOCK_GATE_DISABLE bit should be set, otherwise i2c access will be wrong. v2: Disable CLOCK_GATE_DISABLE bit after bit bashing as suggested by Eric. Signed-off-by: Shaohua Li Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_drv.h | 2 +- drivers/gpu/drm/i915/intel_i2c.c | 17 +++++++++++++++++ drivers/gpu/drm/i915/intel_modes.c | 6 ++++++ 4 files changed, 25 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 521194732266..15da44cf21b1 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -526,6 +526,7 @@ #define DPLLA_INPUT_BUFFER_ENABLE (1 << 0) #define D_STATE 0x6104 #define CG_2D_DIS 0x6200 +#define DPCUNIT_CLOCK_GATE_DISABLE (1 << 24) #define CG_3D_DIS 0x6204 /* diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 957daef8edff..cf2943028936 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -109,7 +109,7 @@ struct intel_i2c_chan *intel_i2c_create(struct drm_device *dev, const u32 reg, void intel_i2c_destroy(struct intel_i2c_chan *chan); int intel_ddc_get_modes(struct intel_output *intel_output); extern bool intel_ddc_probe(struct intel_output *intel_output); - +void intel_i2c_quirk_set(struct drm_device *dev, bool enable); extern void intel_crt_init(struct drm_device *dev); extern void intel_hdmi_init(struct drm_device *dev, int sdvox_reg); extern bool intel_sdvo_init(struct drm_device *dev, int output_device); diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 5ee9d4c25753..f7061f68d050 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -34,6 +34,21 @@ #include "i915_drm.h" #include "i915_drv.h" +void intel_i2c_quirk_set(struct drm_device *dev, bool enable) +{ + struct drm_i915_private *dev_priv = dev->dev_private; + + /* When using bit bashing for I2C, this bit needs to be set to 1 */ + if (!IS_IGD(dev)) + return; + if (enable) + I915_WRITE(CG_2D_DIS, + I915_READ(CG_2D_DIS) | DPCUNIT_CLOCK_GATE_DISABLE); + else + I915_WRITE(CG_2D_DIS, + I915_READ(CG_2D_DIS) & (~DPCUNIT_CLOCK_GATE_DISABLE)); +} + /* * Intel GPIO access functions */ @@ -153,8 +168,10 @@ struct intel_i2c_chan *intel_i2c_create(struct drm_device *dev, const u32 reg, goto out_free; /* JJJ: raise SCL and SDA? */ + intel_i2c_quirk_set(dev, true); set_data(chan, 1); set_clock(chan, 1); + intel_i2c_quirk_set(dev, false); udelay(20); return chan; diff --git a/drivers/gpu/drm/i915/intel_modes.c b/drivers/gpu/drm/i915/intel_modes.c index 07d7ec976168..e0910fefce87 100644 --- a/drivers/gpu/drm/i915/intel_modes.c +++ b/drivers/gpu/drm/i915/intel_modes.c @@ -27,6 +27,7 @@ #include #include "drmP.h" #include "intel_drv.h" +#include "i915_drv.h" /** * intel_ddc_probe @@ -52,7 +53,10 @@ bool intel_ddc_probe(struct intel_output *intel_output) } }; + intel_i2c_quirk_set(intel_output->ddc_bus->drm_dev, true); ret = i2c_transfer(&intel_output->ddc_bus->adapter, msgs, 2); + intel_i2c_quirk_set(intel_output->ddc_bus->drm_dev, false); + if (ret == 2) return true; @@ -70,8 +74,10 @@ int intel_ddc_get_modes(struct intel_output *intel_output) struct edid *edid; int ret = 0; + intel_i2c_quirk_set(intel_output->ddc_bus->drm_dev, true); edid = drm_get_edid(&intel_output->base, &intel_output->ddc_bus->adapter); + intel_i2c_quirk_set(intel_output->ddc_bus->drm_dev, false); if (edid) { drm_mode_connector_update_edid_property(&intel_output->base, edid); -- 2.20.1