Re: [PATCH 04/14] drm/i915: Clean up the .get_cdclk() assignment if ladder

[Ander Conselvan De Oliveira <conselvan2@gmail.com>]

On Mon, 2016-12-19 at 19:35 +0200, Jani Nikula wrote:
> On Mon, 19 Dec 2016, ville.syrjala@linux.intel.com wrote:
> > 
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Let's clean up the mess we have in the if ladder that assigns the
> > .get_cdclk() hooks. The grouping of the platforms by the function
> > results in a thing that's not really legible, so let's do it the
> > other way around and order the if ladder by platform and duplicate
> > whatever assignments we need.
> > 
> > To further avoid confusion with the function names let's rename
> > them to just fixed_<freq>_get_cdclk(). The other option would
> > be to duplicate the functions entirely but it seems quite
> > pointless to do that since each one just returns a fixed value.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_display.c | 41 +++++++++++++++++++++----------
> > -----
> >  1 file changed, 24 insertions(+), 17 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c
> > b/drivers/gpu/drm/i915/intel_display.c
> > index bbfef348783b..29f91e799272 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -7379,22 +7379,22 @@ static int valleyview_get_cdclk(struct
> > drm_i915_private *dev_priv)
> >  				      CCK_DISPLAY_CLOCK_CONTROL);
> >  }
> >  
> > -static int ilk_get_cdclk(struct drm_i915_private *dev_priv)
> > +static int fixed_450mhz_get_cdclk(struct drm_i915_private *dev_priv)
> >  {
> >  	return 450000;
> >  }
> >  
> > -static int i945_get_cdclk(struct drm_i915_private *dev_priv)
> > +static int fixed_400mhz_get_cdclk(struct drm_i915_private *dev_priv)
> >  {
> >  	return 400000;
> >  }
> >  
> > -static int i915_get_cdclk(struct drm_i915_private *dev_priv)
> > +static int fixed_333mhz_get_cdclk(struct drm_i915_private *dev_priv)
> >  {
> >  	return 333333;
> >  }
> >  
> > -static int i9xx_misc_get_cdclk(struct drm_i915_private *dev_priv)
> > +static int fixed_200mhz_get_cdclk(struct drm_i915_private *dev_priv)
> >  {
> >  	return 200000;
> >  }
> > @@ -7444,7 +7444,7 @@ static int i915gm_get_cdclk(struct drm_i915_private
> > *dev_priv)
> >  	}
> >  }
> >  
> > -static int i865_get_cdclk(struct drm_i915_private *dev_priv)
> > +static int fixed_266mhz_get_cdclk(struct drm_i915_private *dev_priv)
> >  {
> >  	return 266667;
> >  }
> > @@ -7487,7 +7487,7 @@ static int i85x_get_cdclk(struct drm_i915_private
> > *dev_priv)
> >  	return 0;
> >  }
> >  
> > -static int i830_get_cdclk(struct drm_i915_private *dev_priv)
> > +static int fixed_133mhz_get_cdclk(struct drm_i915_private *dev_priv)
> >  {
> >  	return 133333;
> >  }
> > @@ -16098,32 +16098,39 @@ void intel_init_display_hooks(struct
> > drm_i915_private *dev_priv)
> >  		dev_priv->display.get_cdclk = haswell_get_cdclk;
> >  	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> >  		dev_priv->display.get_cdclk = valleyview_get_cdclk;
> > +	else if (IS_GEN6(dev_priv) || IS_IVYBRIDGE(dev_priv))
> > +		dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
> >  	else if (IS_GEN5(dev_priv))
> > -		dev_priv->display.get_cdclk = ilk_get_cdclk;
> > -	else if (IS_I945G(dev_priv) || IS_I965G(dev_priv) ||
> > -		 IS_GEN6(dev_priv) || IS_IVYBRIDGE(dev_priv))
> > -		dev_priv->display.get_cdclk = i945_get_cdclk;
> > +		dev_priv->display.get_cdclk = fixed_450mhz_get_cdclk;
> >  	else if (IS_GM45(dev_priv))
> >  		dev_priv->display.get_cdclk = gm45_get_cdclk;
> > +	else if (IS_G4X(dev_priv))
> > +		dev_priv->display.get_cdclk = g33_get_cdclk;
> >  	else if (IS_I965GM(dev_priv))
> >  		dev_priv->display.get_cdclk = i965gm_get_cdclk;
> > +	else if (IS_I965G(dev_priv))
> > +		dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
> >  	else if (IS_PINEVIEW(dev_priv))
> >  		dev_priv->display.get_cdclk = pnv_get_cdclk;
> > -	else if (IS_G33(dev_priv) || IS_G4X(dev_priv))
> > +	else if (IS_G33(dev_priv))
> >  		dev_priv->display.get_cdclk = g33_get_cdclk;
> > -	else if (IS_I915G(dev_priv))
> > -		dev_priv->display.get_cdclk = i915_get_cdclk;
> > -	else if (IS_I945GM(dev_priv) || IS_I845G(dev_priv))
> > -		dev_priv->display.get_cdclk = i9xx_misc_get_cdclk;
> > +	else if (IS_I945GM(dev_priv))
> > +		dev_priv->display.get_cdclk = fixed_200mhz_get_cdclk;
> > +	else if (IS_I945G(dev_priv))
> > +		dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
> >  	else if (IS_I915GM(dev_priv))
> >  		dev_priv->display.get_cdclk = i915gm_get_cdclk;
> > +	else if (IS_I915G(dev_priv))
> > +		dev_priv->display.get_cdclk = fixed_333mhz_get_cdclk;
> >  	else if (IS_I865G(dev_priv))
> > -		dev_priv->display.get_cdclk = i865_get_cdclk;
> > +		dev_priv->display.get_cdclk = fixed_266mhz_get_cdclk;
> >  	else if (IS_I85X(dev_priv))
> >  		dev_priv->display.get_cdclk = i85x_get_cdclk;
> > +	else  if (IS_I845G(dev_priv))
> > +		dev_priv->display.get_cdclk = fixed_200mhz_get_cdclk;
> >  	else { /* 830 */
> >  		WARN(!IS_I830(dev_priv), "Unknown platform. Assuming 133
> > MHz CDCLK\n");
> > -		dev_priv->display.get_cdclk = i830_get_cdclk;
> > +		dev_priv->display.get_cdclk = fixed_133mhz_get_cdclk;
> >  	}
> I wonder if "switch (dev_priv->info.platform)" is a viable alternative
> to some of the worst if ladders we have, like this one.

How about something like this?

struct cdclk_iface {
	int (*get)(...);
	void (*set)(...);
	int (*calc)(...);

	int fixed;
};

static int fixed_cdclk_get(struct drm_i915_private *dev_priv)
{
	return INTEL_INFO(dev_priv)->cdclk.fixed;
}

#define FIXED_CDCLK(value)	\
	{ .get = fixed_cdclk_get, .fixed = value }

struct cdclk_iface skl_cdclk = {
	.get = skl_get_cdclk,
	.set = skl_set_cdclk,
	.calc = skl_get_cdclk,
};

...

And then in device info we just do either

  .cdclk = FIXED_CDCLK(value),

or 

  .cdclk = skl_cdclk,

Ander

> 
> BR,
> Jani.
> 
> 
> > 
> >  
> >  	if (IS_GEN5(dev_priv)) {
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