Re: [PATCH 06/40] drm/i915: Add cdclk change support for chv

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, Jul 29, 2014 at 09:51:03AM -0700, Jesse Barnes wrote:
> On Sat, 28 Jun 2014 02:03:57 +0300
> ville.syrjala@linux.intel.com wrote:
> 
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Looks like the Punit is supposed to support the 400MHz cdclk directly on
> > chv, so we don't need the vlv tricks.
> > 
> > FIXME: Punit doesn't seem ready for this yet on current hw
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h      |  4 +++
> >  drivers/gpu/drm/i915/intel_display.c | 50 ++++++++++++++++++++++++++++++++++--
> >  2 files changed, 52 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index f156591..e296312 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -491,6 +491,10 @@
> >  #define BUNIT_REG_BISOC				0x11
> >  
> >  #define PUNIT_REG_DSPFREQ			0x36
> > +#define   DSPFREQSTAT_SHIFT_CHV			24
> > +#define   DSPFREQSTAT_MASK_CHV			(0x1f << DSPFREQSTAT_SHIFT_CHV)
> > +#define   DSPFREQGUAR_SHIFT_CHV			8
> > +#define   DSPFREQGUAR_MASK_CHV			(0x1f << DSPFREQGUAR_SHIFT_CHV)
> >  #define   DSPFREQSTAT_SHIFT			30
> >  #define   DSPFREQSTAT_MASK			(0x3 << DSPFREQSTAT_SHIFT)
> >  #define   DSPFREQGUAR_SHIFT			14
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 99c10d1..9af1d13 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -4529,6 +4529,47 @@ static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
> >  	vlv_update_cdclk(dev);
> >  }
> >  
> > +static void cherryview_set_cdclk(struct drm_device *dev, int cdclk)
> > +{
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	u32 val, cmd;
> > +
> > +	WARN_ON(dev_priv->display.get_display_clock_speed(dev) != dev_priv->vlv_cdclk_freq);
> > +
> > +	switch (cdclk) {
> > +	case 400000:
> > +		cmd = 3;
> > +		break;
> > +	case 333333:
> > +	case 320000:
> > +		cmd = 2;
> > +		break;
> > +	case 266667:
> > +		cmd = 1;
> > +		break;
> > +	case 200000:
> > +		cmd = 0;
> > +		break;
> > +	default:
> > +		WARN_ON(1);
> > +		return;
> > +	}
> > +
> > +	mutex_lock(&dev_priv->rps.hw_lock);
> > +	val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
> > +	val &= ~DSPFREQGUAR_MASK_CHV;
> > +	val |= (cmd << DSPFREQGUAR_SHIFT_CHV);
> > +	vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, val);
> > +	if (wait_for((vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ) &
> > +		      DSPFREQSTAT_MASK_CHV) == (cmd << DSPFREQSTAT_SHIFT_CHV),
> > +		     50)) {
> > +		DRM_ERROR("timed out waiting for CDclk change\n");
> > +	}
> > +	mutex_unlock(&dev_priv->rps.hw_lock);
> > +
> > +	vlv_update_cdclk(dev);
> > +}
> > +
> >  static int valleyview_calc_cdclk(struct drm_i915_private *dev_priv,
> >  				 int max_pixclk)
> >  {
> > @@ -4597,8 +4638,13 @@ static void valleyview_modeset_global_resources(struct drm_device *dev)
> >  	int max_pixclk = intel_mode_max_pixclk(dev_priv);
> >  	int req_cdclk = valleyview_calc_cdclk(dev_priv, max_pixclk);
> >  
> > -	if (req_cdclk != dev_priv->vlv_cdclk_freq)
> > -		valleyview_set_cdclk(dev, req_cdclk);
> > +	if (req_cdclk != dev_priv->vlv_cdclk_freq) {
> > +		if (IS_CHERRYVIEW(dev))
> > +			cherryview_set_cdclk(dev, req_cdclk);
> > +		else
> > +			valleyview_set_cdclk(dev, req_cdclk);
> > +	}
> > +
> >  	modeset_update_crtc_power_domains(dev);
> >  }
> >  
> 
> Which doc has these Punit commands?  I'm assuming you have them
> correct, but a ref would be good if we don't already have one.

These were in the punit has. The display cluster has still had the old
vlv information last I looked.

> 
> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
> 
> There should probably be a JIRA for this too so QA can verify once we
> have updated punit support.
> 
> -- 
> Jesse Barnes, Intel Open Source Technology Center

-- 
Ville Syrjälä
Intel OTC