Re: [PATCH 60/89] drm/i915/skl: CD clock back calculation for SKL

M, Satheeshakrishna
2014-10-01T10:51:46Z

On 9/23/2014 12:49 AM, Paulo Zanoni wrote:
> 2014-09-04 8:27 GMT-03:00 Damien Lespiau<damien.lespiau@intel.com>:
>> From: Satheeshakrishna M<satheeshakrishna.m@intel.com>
>>
>> Determine programmed cd clock for SKL.
>>
>> v2: Fix the LCPLL1 enable warning logic
>>
>> v3: Rebase over the hsw pll rework.
>>
>> v4: Rebase on top of the per-platform split (Damien)
>>
>> Signed-off-by: Satheeshakrishna M<satheeshakrishna.m@intel.com>
>> Signed-off-by: Damien Lespiau<damien.lespiau@intel.com>
>> ---
>> drivers/gpu/drm/i915/intel_ddi.c | 76 +++++++++++++++++++++++++++++++++++-----
>> 1 file changed, 67 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
>> index ba1103f..e7a5428 100644
>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>> @@ -1260,6 +1260,55 @@ static void intel_disable_ddi(struct intel_encoder *intel_encoder)
>> }
>> }
>>
>> +static int skl_get_cdclk_freq(struct drm_i915_private *dev_priv)
>> +{
>> + uint32_t lcpll1 = I915_READ(LCPLL1_CTL);
>> + uint32_t cdctl = I915_READ(CDCLK_CTL);
>> + uint32_t linkrate;
>> +
>> + if (!(lcpll1 & LCPLL_PLL_ENABLE)) {
>> + WARN(1, "LCPLL1 not enabled\n");
>> + return 24000; /* 24MHz is the cd freq with NSSC ref */
>> + }
>> +
>> + if ((cdctl & CDCLK_FREQ_SEL_MASK) == CDCLK_FREQ_540)
>> + return 540000;
>> +
>> + linkrate = (I915_READ(DPLL_CTRL1) &
>> + DPLL_CRTL1_LINK_RATE_MASK(SKL_DPLL0)) >> 1;
>> +
>> + if (linkrate == DPLL_CRTL1_LINK_RATE_2160 ||
>> + linkrate == DPLL_CRTL1_LINK_RATE_1080) {
>> + /* vco 8640 */
>> + switch (cdctl & CDCLK_FREQ_SEL_MASK) {
>> + case CDCLK_FREQ_450_432:
>> + return 432000;
>> + case CDCLK_FREQ_337_308:
>> + return 308570;
>> + case CDCLK_FREQ_675_617:
>> + return 617140;
>> + break;
> This is the only line with a "break" after a return :)
oops.. will remove it
>
>> + default:
>> + WARN(1, "Unknown cd freq selection\n");
>> + }
>> + } else {
>> + /* vco 8100 */
>> + switch (cdctl & CDCLK_FREQ_SEL_MASK) {
>> + case CDCLK_FREQ_450_432:
>> + return 450000;
>> + case CDCLK_FREQ_337_308:
>> + return 337500;
>> + case CDCLK_FREQ_675_617:
>> + return 675000;
>> + default:
>> + WARN(1, "Unknown cd freq selection\n");
>> + }
>> + }
>> +
>> + /* error case, do as if DPLL0 isn't enabled */
>> + return 24000;
>> +}
>> +
>> static int bdw_get_cdclk_freq(struct drm_i915_private *dev_priv)
>> {
>> uint32_t lcpll = I915_READ(LCPLL_CTL);
>> @@ -1301,6 +1350,9 @@ int intel_ddi_get_cdclk_freq(struct drm_i915_private *dev_priv)
>> {
>> struct drm_device *dev = dev_priv->dev;
>>
>> + if (IS_SKYLAKE(dev))
>> + return skl_get_cdclk_freq(dev_priv);
>> +
> I hope someone will replace this with a "switch (INTEL_INFO(gen))"
> before Gen 15 :)
>
> With or without changes: Reviewed-by: Paulo Zanoni<paulo.r.zanoni@intel.com>
>
>
>> if (IS_BROADWELL(dev))
>> return bdw_get_cdclk_freq(dev_priv);
>>
>> @@ -1369,19 +1421,25 @@ void intel_ddi_pll_init(struct drm_device *dev)
>>
>> hsw_shared_dplls_init(dev_priv);
>>
>> - /* The LCPLL register should be turned on by the BIOS. For now let's
>> - * just check its state and print errors in case something is wrong.
>> - * Don't even try to turn it on.
>> - */
>> -
>> DRM_DEBUG_KMS("CDCLK running at %dKHz\n",
>> intel_ddi_get_cdclk_freq(dev_priv));
>>
>> - if (val & LCPLL_CD_SOURCE_FCLK)
>> - DRM_ERROR("CDCLK source is not LCPLL\n");
>> + if (IS_SKYLAKE(dev)) {
>> + if (!(I915_READ(LCPLL1_CTL) & LCPLL_PLL_ENABLE))
>> + DRM_ERROR("LCPLL1 is disabled\n");
>> + } else {
>> + /*
>> + * The LCPLL register should be turned on by the BIOS. For now
>> + * let's just check its state and print errors in case
>> + * something is wrong. Don't even try to turn it on.
>> + */
>> +
>> + if (val & LCPLL_CD_SOURCE_FCLK)
>> + DRM_ERROR("CDCLK source is not LCPLL\n");
>>
>> - if (val & LCPLL_PLL_DISABLE)
>> - DRM_ERROR("LCPLL is disabled\n");
>> + if (val & LCPLL_PLL_DISABLE)
>> + DRM_ERROR("LCPLL is disabled\n");
>> + }
>> }
>>
>> void intel_ddi_prepare_link_retrain(struct drm_encoder *encoder)
>> --
>> 1.8.3.1
>>
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>