[Intel-gfx] [PATCH 5/6] drm/i915: Read out VGA dotclock properly on LPT

[Imre Deak]

On ke, 2016-02-17 at 21:41 +0200, ville.syrjala at linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Rather than assume the VGA dotclock is really the FDI based thing,
> let's read out the real thing via iclkip, and after readout it'll
> get to compare it with the FDI based number to make sure they're
> in sync.
> 
> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Reviewed-by: Imre Deak <imre.deak at intel.com>

> ---
>  drivers/gpu/drm/i915/i915_reg.h      |  8 ++++++--
>  drivers/gpu/drm/i915/intel_crt.c     |  4 ++++
>  drivers/gpu/drm/i915/intel_display.c | 37
> ++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h     |  1 +
>  4 files changed, 48 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h
> index 3774870477c1..a5f2c6e2edb2 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -7362,9 +7362,11 @@ enum skl_disp_power_wells {
>  /* SBI offsets */
>  #define  SBI_SSCDIVINTPHASE			0x0200
>  #define  SBI_SSCDIVINTPHASE6			0x0600
> -#define   SBI_SSCDIVINTPHASE_DIVSEL_MASK	((0x7f)<<1)
> +#define   SBI_SSCDIVINTPHASE_DIVSEL_SHIFT	1
> +#define   SBI_SSCDIVINTPHASE_DIVSEL_MASK	(0x7f<<1)
>  #define   SBI_SSCDIVINTPHASE_DIVSEL(x)		((x)<<1)
> -#define   SBI_SSCDIVINTPHASE_INCVAL_MASK	((0x7f)<<8)
> +#define   SBI_SSCDIVINTPHASE_INCVAL_SHIFT	8
> +#define   SBI_SSCDIVINTPHASE_INCVAL_MASK	(0x7f<<8)
>  #define   SBI_SSCDIVINTPHASE_INCVAL(x)		((x)<<8)
>  #define   SBI_SSCDIVINTPHASE_DIR(x)		((x)<<15)
>  #define   SBI_SSCDIVINTPHASE_PROPAGATE		(1<<0)
> @@ -7374,6 +7376,8 @@ enum skl_disp_power_wells {
>  #define   SBI_SSCCTL_PATHALT			(1<<3)
>  #define   SBI_SSCCTL_DISABLE			(1<<0)
>  #define  SBI_SSCAUXDIV6				0x0610
> +#define   SBI_SSCAUXDIV_FINALDIV2SEL_SHIFT	4
> +#define   SBI_SSCAUXDIV_FINALDIV2SEL_MASK	(1<<4)
>  #define   SBI_SSCAUXDIV_FINALDIV2SEL(x)		((x)<<4)
>  #define  SBI_DBUFF0				0x2a00
>  #define  SBI_GEN0				0x1f00
> diff --git a/drivers/gpu/drm/i915/intel_crt.c
> b/drivers/gpu/drm/i915/intel_crt.c
> index f4c88d93a164..08964bbd7c82 100644
> --- a/drivers/gpu/drm/i915/intel_crt.c
> +++ b/drivers/gpu/drm/i915/intel_crt.c
> @@ -128,6 +128,8 @@ static void intel_crt_get_config(struct
> intel_encoder *encoder,
>  static void hsw_crt_get_config(struct intel_encoder *encoder,
>  			       struct intel_crtc_state *pipe_config)
>  {
> +	struct drm_i915_private *dev_priv = to_i915(encoder-
> >base.dev);
> +
>  	intel_ddi_get_config(encoder, pipe_config);
>  
>  	pipe_config->base.adjusted_mode.flags &=
> ~(DRM_MODE_FLAG_PHSYNC |
> @@ -135,6 +137,8 @@ static void hsw_crt_get_config(struct
> intel_encoder *encoder,
>  					      DRM_MODE_FLAG_PVSYNC |
>  					      DRM_MODE_FLAG_NVSYNC);
>  	pipe_config->base.adjusted_mode.flags |=
> intel_crt_get_flags(encoder);
> +
> +	pipe_config->base.adjusted_mode.crtc_clock =
> lpt_get_iclkip(dev_priv);
>  }
>  
>  /* Note: The caller is required to filter out dpms modes not
> supported by the
> diff --git a/drivers/gpu/drm/i915/intel_display.c
> b/drivers/gpu/drm/i915/intel_display.c
> index 5e7b22a31098..43cae2f8016d 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4032,6 +4032,43 @@ static void lpt_program_iclkip(struct drm_crtc
> *crtc)
>  	I915_WRITE(PIXCLK_GATE, PIXCLK_GATE_UNGATE);
>  }
>  
> +int lpt_get_iclkip(struct drm_i915_private *dev_priv)
> +{
> +	u32 divsel, phaseinc, auxdiv;
> +	u32 iclk_virtual_root_freq = 172800 * 1000;
> +	u32 iclk_pi_range = 64;
> +	u32 desired_divisor;
> +	u32 temp;
> +
> +	if ((I915_READ(PIXCLK_GATE) & PIXCLK_GATE_UNGATE) == 0)
> +		return 0;
> +
> +	mutex_lock(&dev_priv->sb_lock);
> +
> +	temp = intel_sbi_read(dev_priv, SBI_SSCCTL6, SBI_ICLK);
> +	if (temp & SBI_SSCCTL_DISABLE) {
> +		mutex_unlock(&dev_priv->sb_lock);
> +		return 0;
> +	}
> +
> +	temp = intel_sbi_read(dev_priv, SBI_SSCDIVINTPHASE6,
> SBI_ICLK);
> +	divsel = (temp & SBI_SSCDIVINTPHASE_DIVSEL_MASK) >>
> +		SBI_SSCDIVINTPHASE_DIVSEL_SHIFT;
> +	phaseinc = (temp & SBI_SSCDIVINTPHASE_INCVAL_MASK) >>
> +		SBI_SSCDIVINTPHASE_INCVAL_SHIFT;
> +
> +	temp = intel_sbi_read(dev_priv, SBI_SSCAUXDIV6, SBI_ICLK);
> +	auxdiv = (temp & SBI_SSCAUXDIV_FINALDIV2SEL_MASK) >>
> +		SBI_SSCAUXDIV_FINALDIV2SEL_SHIFT;
> +
> +	mutex_unlock(&dev_priv->sb_lock);
> +
> +	desired_divisor = (divsel + 2) * iclk_pi_range + phaseinc;
> +
> +	return DIV_ROUND_CLOSEST(iclk_virtual_root_freq,
> +				 desired_divisor << auxdiv);
> +}
> +
>  static void ironlake_pch_transcoder_set_timings(struct intel_crtc
> *crtc,
>  						enum pipe
> pch_transcoder)
>  {
> diff --git a/drivers/gpu/drm/i915/intel_drv.h
> b/drivers/gpu/drm/i915/intel_drv.h
> index c25a8880b4e8..3b64c9b002a8 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1158,6 +1158,7 @@ struct intel_shared_dpll
> *intel_get_shared_dpll(struct intel_crtc *crtc,
>  int vlv_force_pll_on(struct drm_device *dev, enum pipe pipe,
>  		     const struct dpll *dpll);
>  void vlv_force_pll_off(struct drm_device *dev, enum pipe pipe);
> +int lpt_get_iclkip(struct drm_i915_private *dev_priv);
>  
>  /* modesetting asserts */
>  void assert_panel_unlocked(struct drm_i915_private *dev_priv,