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

Jesse Barnes
2014-07-29T16:50:58Z

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.

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