Re: [BXT MIPI PATCH v3 08/14] drm/i915/bxt: DSI disable and post-disable

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

On Tue, 01 Sep 2015, Uma Shankar <uma.shankar@intel.com> wrote:
> From: Shashank Sharma <shashank.sharma@intel.com>
>
> This patch contains changes to support DSI disble sequence in BXT.
> The changes are:
> 1. BXT specific changes in clear_device_ready function.
> 2. BXT specific changes in DSI disable and post-disable functions.
> 3. Add a new function to reset BXT Dphy clock and dividers
>    (bxt_dsi_reset_clocks).
> 4. Moved some part of the vlv clock reset code, in a new function
>    (vlv_dsi_reset_clocks) maintaining the exact same sequence.
> 5. Wrapper function to call corresponding reset clock function.
>
> v2: Fixed Jani's review comments.
>
> v3: Removed the GET_DSI_PORT_CTRL Macro for consistency with earlier
>     implementations as per Jani's suggestion.
>
> Signed-off-by: Uma Shankar <uma.shankar@intel.com>
> Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


> ---
>  drivers/gpu/drm/i915/intel_dsi.c     |   36 +++++++++++++++++--------------
>  drivers/gpu/drm/i915/intel_dsi.h     |    2 ++
>  drivers/gpu/drm/i915/intel_dsi_pll.c |   39 ++++++++++++++++++++++++++++++++++
>  3 files changed, 61 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index 5a42f87..110a895 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -421,12 +421,15 @@ static void intel_dsi_port_disable(struct intel_encoder *encoder)
>  	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
>  	enum port port;
>  	u32 temp;
> +	u32 port_ctrl;
>  
>  	for_each_dsi_port(port, intel_dsi->ports) {
>  		/* de-assert ip_tg_enable signal */
> -		temp = I915_READ(MIPI_PORT_CTRL(port));
> -		I915_WRITE(MIPI_PORT_CTRL(port), temp & ~DPI_ENABLE);
> -		POSTING_READ(MIPI_PORT_CTRL(port));
> +		port_ctrl = IS_BROXTON(dev) ? BXT_MIPI_PORT_CTRL(port) :
> +						MIPI_PORT_CTRL(port);
> +		temp = I915_READ(port_ctrl);
> +		I915_WRITE(port_ctrl, temp & ~DPI_ENABLE);
> +		POSTING_READ(port_ctrl);
>  	}
>  }
>  
> @@ -550,12 +553,7 @@ static void intel_dsi_disable(struct intel_encoder *encoder)
>  		/* Panel commands can be sent when clock is in LP11 */
>  		I915_WRITE(MIPI_DEVICE_READY(port), 0x0);
>  
> -		temp = I915_READ(MIPI_CTRL(port));
> -		temp &= ~ESCAPE_CLOCK_DIVIDER_MASK;
> -		I915_WRITE(MIPI_CTRL(port), temp |
> -			   intel_dsi->escape_clk_div <<
> -			   ESCAPE_CLOCK_DIVIDER_SHIFT);
> -
> +		intel_dsi_reset_clocks(encoder, port);
>  		I915_WRITE(MIPI_EOT_DISABLE(port), CLOCKSTOP);
>  
>  		temp = I915_READ(MIPI_DSI_FUNC_PRG(port));
> @@ -574,10 +572,12 @@ static void intel_dsi_disable(struct intel_encoder *encoder)
>  
>  static void intel_dsi_clear_device_ready(struct intel_encoder *encoder)
>  {
> +	struct drm_device *dev = encoder->base.dev;
>  	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
>  	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
>  	enum port port;
>  	u32 val;
> +	u32 port_ctrl = 0;
>  
>  	DRM_DEBUG_KMS("\n");
>  	for_each_dsi_port(port, intel_dsi->ports) {
> @@ -594,18 +594,22 @@ static void intel_dsi_clear_device_ready(struct intel_encoder *encoder)
>  							ULPS_STATE_ENTER);
>  		usleep_range(2000, 2500);
>  
> +		if (IS_BROXTON(dev))
> +			port_ctrl = BXT_MIPI_PORT_CTRL(port);
> +		else if (IS_VALLEYVIEW(dev))
> +			/* Common bit for both MIPI Port A & MIPI Port C */
> +			port_ctrl = MIPI_PORT_CTRL(PORT_A);
> +
>  		/* Wait till Clock lanes are in LP-00 state for MIPI Port A
>  		 * only. MIPI Port C has no similar bit for checking
>  		 */
> -		if (wait_for(((I915_READ(MIPI_PORT_CTRL(PORT_A)) & AFE_LATCHOUT)
> -							== 0x00000), 30))
> +		if (wait_for(((I915_READ(port_ctrl) & AFE_LATCHOUT)
> +						== 0x00000), 30))
>  			DRM_ERROR("DSI LP not going Low\n");
>  
> -		/* Disable MIPI PHY transparent latch
> -		 * Common bit for both MIPI Port A & MIPI Port C
> -		 */
> -		val = I915_READ(MIPI_PORT_CTRL(PORT_A));
> -		I915_WRITE(MIPI_PORT_CTRL(PORT_A), val & ~LP_OUTPUT_HOLD);
> +		/* Disable MIPI PHY transparent latch */
> +		val = I915_READ(port_ctrl);
> +		I915_WRITE(port_ctrl, val & ~LP_OUTPUT_HOLD);
>  		usleep_range(1000, 1500);
>  
>  		I915_WRITE(MIPI_DEVICE_READY(port), 0x00);
> diff --git a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h
> index 759983e..078ea1b 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.h
> +++ b/drivers/gpu/drm/i915/intel_dsi.h
> @@ -124,6 +124,8 @@ static inline struct intel_dsi *enc_to_intel_dsi(struct drm_encoder *encoder)
>  extern void intel_enable_dsi_pll(struct intel_encoder *encoder);
>  extern void intel_disable_dsi_pll(struct intel_encoder *encoder);
>  extern u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp);
> +extern void intel_dsi_reset_clocks(struct intel_encoder *encoder,
> +							enum port port);
>  
>  struct drm_panel *vbt_panel_init(struct intel_dsi *intel_dsi, u16 panel_id);
>  
> diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c
> index 63f9aed..918bc5f 100644
> --- a/drivers/gpu/drm/i915/intel_dsi_pll.c
> +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c
> @@ -389,6 +389,19 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp)
>  	return pclk;
>  }
>  
> +void vlv_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
> +{
> +	u32 temp;
> +	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
> +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> +
> +	temp = I915_READ(MIPI_CTRL(port));
> +	temp &= ~ESCAPE_CLOCK_DIVIDER_MASK;
> +	I915_WRITE(MIPI_CTRL(port), temp |
> +			intel_dsi->escape_clk_div <<
> +			ESCAPE_CLOCK_DIVIDER_SHIFT);
> +}
> +
>  /* Program BXT Mipi clocks and dividers */
>  static void bxt_dsi_program_clocks(struct drm_device *dev, enum port port)
>  {
> @@ -530,3 +543,29 @@ void intel_disable_dsi_pll(struct intel_encoder *encoder)
>  	else if (IS_BROXTON(dev))
>  		bxt_disable_dsi_pll(encoder);
>  }
> +
> +void bxt_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
> +{
> +	u32 tmp;
> +	struct drm_device *dev = encoder->base.dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +	/* Clear old configurations */
> +	tmp = I915_READ(BXT_MIPI_CLOCK_CTL);
> +	tmp &= ~(BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port));
> +	tmp &= ~(BXT_MIPI_RX_ESCLK_FIXDIV_MASK(port));
> +	tmp &= ~(BXT_MIPI_ESCLK_VAR_DIV_MASK(port));
> +	tmp &= ~(BXT_MIPI_DPHY_DIVIDER_MASK(port));
> +	I915_WRITE(BXT_MIPI_CLOCK_CTL, tmp);
> +	I915_WRITE(MIPI_EOT_DISABLE(port), CLOCKSTOP);
> +}
> +
> +void intel_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
> +{
> +	struct drm_device *dev = encoder->base.dev;
> +
> +	if (IS_BROXTON(dev))
> +		bxt_dsi_reset_clocks(encoder, port);
> +	else if (IS_VALLEYVIEW(dev))
> +		vlv_dsi_reset_clocks(encoder, port);
> +}
> -- 
> 1.7.9.5
>

-- 
Jani Nikula, Intel Open Source Technology Center
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