Re: [PATCH] drm/i915: Add MIPI_IO WA and program DSI regulators

[Jani Nikula <jani.nikula@intel.com>]

On Thu, 19 Jan 2017, Mika Kahola <mika.kahola@intel.com> wrote:
> On Thu, 2017-01-19 at 11:41 +0530, Vidya Srinivas wrote:
>> From: Uma Shankar <uma.shankar@intel.com>
>> 
>> Enable MIPI IO WA for BXT DSI as per bspec and
>> program the DSI regulators.
>> 
>> v2: Moved IO enable to pre-enable as per Mika's
>> review comments. Also reused the existing register
>> definition for BXT_P_CR_GT_DISP_PWRON.
>> 
>> v3: Added Programming the DSI regulators as per disable/enable
>> sequences.
>> 
>> Signed-off-by: Uma Shankar <uma.shankar@intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_reg.h  |  7 +++++++
>>  drivers/gpu/drm/i915/intel_dsi.c | 21 +++++++++++++++++++++
>>  2 files changed, 28 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h
>> b/drivers/gpu/drm/i915/i915_reg.h
>> index 00970aa..0a9ad44 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -1553,6 +1553,7 @@ enum skl_disp_power_wells {
>>  	_MMIO(_BXT_PHY_CH(phy, ch, reg_ch0, reg_ch1))
>>  
>>  #define BXT_P_CR_GT_DISP_PWRON		_MMIO(0x138090)
>> +#define  MIPIO_RST_CTRL				(1 << 2)
>>  
>>  #define _BXT_PHY_CTL_DDI_A		0x64C00
>>  #define _BXT_PHY_CTL_DDI_B		0x64C10
>> @@ -8301,6 +8302,12 @@ enum {
>>  #define _BXT_MIPIC_PORT_CTRL				0x6B8C0
>>  #define BXT_MIPI_PORT_CTRL(tc)	_MMIO_MIPI(tc,
>> _BXT_MIPIA_PORT_CTRL, _BXT_MIPIC_PORT_CTRL)
>>  
>> +#define BXT_P_DSI_REGULATOR_CFG			_MMIO(0x16002
>> 0)
>> +#define  STAP_SELECT					(1 << 0)
>> +
>> +#define BXT_P_DSI_REGULATOR_TX_CTRL		_MMIO(0x160054)
>> +#define  HS_IO_CTRL_SELECT				(1 << 0)
>> +
>>  #define  DPI_ENABLE					(1 << 31)
>> /* A + C */
>>  #define  MIPIA_MIPI4DPHY_DELAY_COUNT_SHIFT		27
>>  #define  MIPIA_MIPI4DPHY_DELAY_COUNT_MASK		(0xf << 27)
>> diff --git a/drivers/gpu/drm/i915/intel_dsi.c
>> b/drivers/gpu/drm/i915/intel_dsi.c
>> index 16732e7..043441e 100644
>> --- a/drivers/gpu/drm/i915/intel_dsi.c
>> +++ b/drivers/gpu/drm/i915/intel_dsi.c
>> @@ -548,6 +548,7 @@ static void intel_dsi_pre_enable(struct
>> intel_encoder *encoder,
>>  	struct drm_i915_private *dev_priv = to_i915(encoder-
>> >base.dev);
>>  	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder-
>> >base);
>>  	enum port port;
>> +	u32 val;
>>  
>>  	DRM_DEBUG_KMS("\n");
>>  
>> @@ -558,6 +559,11 @@ static void intel_dsi_pre_enable(struct
>> intel_encoder *encoder,
>>  	intel_disable_dsi_pll(encoder);
>>  	intel_enable_dsi_pll(encoder, pipe_config);
>>  
>> +	/* Add MIPI IO reset programming for modeset */
>> +	val = I915_READ(BXT_P_CR_GT_DISP_PWRON);
>> +	I915_WRITE(BXT_P_CR_GT_DISP_PWRON,
>> +				val | MIPIO_RST_CTRL);
>> +
> Looking good but overall we still need to address Jani's comment to
> limit these changes only to Broxton platform.

Please don't send this in reply to the current thread...

BR,
Jani.


>
>>  	intel_dsi_prepare(encoder, pipe_config);
>>  
>>  	/* Panel Enable over CRC PMIC */
>> @@ -575,6 +581,12 @@ static void intel_dsi_pre_enable(struct
>> intel_encoder *encoder,
>>  		I915_WRITE(DSPCLK_GATE_D, val);
>>  	}
>>  
>> +	/* Power up DSI regulator */
>> +	I915_WRITE(BXT_P_DSI_REGULATOR_CFG, STAP_SELECT);
>> +	val = I915_READ(BXT_P_DSI_REGULATOR_TX_CTRL);
>> +	val &= ~HS_IO_CTRL_SELECT;
>> +	I915_WRITE(BXT_P_DSI_REGULATOR_TX_CTRL, val);
>> + 	/* put device in ready state */
>>  	intel_dsi_device_ready(encoder);
>>  
>> @@ -707,6 +719,7 @@ static void intel_dsi_post_disable(struct
>> intel_encoder *encoder,
>>  {
>>  	struct drm_i915_private *dev_priv = to_i915(encoder-
>> >base.dev);
>>  	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder-
>> >base);
>> +	u32 val;
>>  
>>  	DRM_DEBUG_KMS("\n");
>>  
>> @@ -714,8 +727,16 @@ static void intel_dsi_post_disable(struct
>> intel_encoder *encoder,
>>  
>>  	intel_dsi_clear_device_ready(encoder);
>>  
>> +	val = I915_READ(BXT_P_CR_GT_DISP_PWRON);
>> +	I915_WRITE(BXT_P_CR_GT_DISP_PWRON,
>> +				val & ~MIPIO_RST_CTRL);
>> +
>>  	intel_disable_dsi_pll(encoder);
>>  
>> +	/* Power down DSI regulator to save power */
>> +	I915_WRITE(BXT_P_DSI_REGULATOR_CFG, STAP_SELECT);
>> +	I915_WRITE(BXT_P_DSI_REGULATOR_TX_CTRL, HS_IO_CTRL_SELECT);
>> +
>>  	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
>>  		u32 val;
>>  

-- 
Jani Nikula, Intel Open Source Technology Center
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