From 203ca94a076a820bd60c4f116e35650e5beffca0 Mon Sep 17 00:00:00 2001
From: Mika Kahola <mika.kahola@intel.com>
Date: Fri, 19 Nov 2021 15:13:47 +0200
Subject: drm/i915/display/dg2: Read CD clock from squasher table
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Git-commit: 77ab3a1ecb1986c17644c48b66d9de0a9a0307c9
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
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
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/display/intel_cdclk.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index 62ed5b73d30e..728263cf40e3 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -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:
/*
--
2.38.1