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Commit 0ba0e9e1 authored by Shaohua Li's avatar Shaohua Li Committed by Eric Anholt
Browse files

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: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
parent 13f4c435

drivers/gpu/drm/i915/i915_reg.h

+1 −0
Original line number Diff line number Diff line
@@ -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



/*

drivers/gpu/drm/i915/intel_drv.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

drivers/gpu/drm/i915/intel_i2c.c

+17 −0
Original line number Diff line number Diff line
@@ -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;

drivers/gpu/drm/i915/intel_modes.c

+6 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/fb.h>

#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);