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drm/i915/display/dg2: Read CD clock from squasher table

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To calculate CD clock with squasher unit, we set CD clock ratio to fixed value of 34.
The CD clock value is read from CD clock squasher table.

BSpec: 54034

v2: Read ratio from register (Ville)
    Drop unnecessary local variable (Ville)
    Get CD clock from the given table
v3: Calculate CD clock frequency based on waveform bit pattern (Ville)
[v4: vsyrjala: Actually do a proper blind readout from the hardware]
[v5: vsyrjala: Use has_cdclk_squasher()]

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211119131348.725220-5-mika.kahola@intel.com
This commit is contained in:
Mika Kahola 2021-11-19 15:13:47 +02:00 committed by Stanislav Lisovskiy
parent 2060a6895b
commit 77ab3a1ecb
1 changed files with 16 additions and 1 deletions
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17
drivers/gpu/drm/i915/display/intel_cdclk.c
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@ -1466,6 +1466,7 @@ static void bxt_de_pll_readout(struct drm_i915_private *dev_priv,
static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
struct intel_cdclk_config *cdclk_config)
{
u32 squash_ctl = 0;
u32 divider;
int div;
@ -1503,7 +1504,21 @@ static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
return;
}
cdclk_config->cdclk = DIV_ROUND_CLOSEST(cdclk_config->vco, div);
if (has_cdclk_squasher(dev_priv))
squash_ctl = intel_de_read(dev_priv, CDCLK_SQUASH_CTL);
if (squash_ctl & CDCLK_SQUASH_ENABLE) {
u16 waveform;
int size;
size = REG_FIELD_GET(CDCLK_SQUASH_WINDOW_SIZE_MASK, squash_ctl) + 1;
waveform = REG_FIELD_GET(CDCLK_SQUASH_WAVEFORM_MASK, squash_ctl) >> (16 - size);
cdclk_config->cdclk = DIV_ROUND_CLOSEST(hweight16(waveform) *
cdclk_config->vco, size * div);
} else {
cdclk_config->cdclk = DIV_ROUND_CLOSEST(cdclk_config->vco, div);
}
out:
/*