[Intel-gfx] [PATCH 3/4] drm/i915/display/dg2: Sanitize CD clock

Mika Kahola
2021-11-18T08:55:13Z

In case of CD clock squashing the divider is always 1. We don't
need to calculate the divider in use so let's skip that for DG2.

v2: Drop unnecessary local variable (Ville)
v3: Avoid if-else structure (Ville)
[v4: vsyrjala: Fix cd2x divider calculation (Uma),
Introduce has_cdclk_squasher()]

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/display/intel_cdclk.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index 630a53d4f882..e8c58779c2a8 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -1212,6 +1212,11 @@ static void skl_cdclk_uninit_hw(struct drm_i915_private *dev_priv)
skl_set_cdclk(dev_priv, &cdclk_config, INVALID_PIPE);
}

+static bool has_cdclk_squasher(struct drm_i915_private *i915)
+{
+ return IS_DG2(i915);
+}
+
static const struct intel_cdclk_vals bxt_cdclk_table[] = {
{ .refclk = 19200, .cdclk = 144000, .divider = 8, .ratio = 60 },
{ .refclk = 19200, .cdclk = 288000, .divider = 4, .ratio = 60 },
@@ -1750,7 +1755,7 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
static void bxt_sanitize_cdclk(struct drm_i915_private *dev_priv)
{
u32 cdctl, expected;
- int cdclk, vco;
+ int cdclk, clock, vco;

intel_update_cdclk(dev_priv);
intel_dump_cdclk_config(&dev_priv->cdclk.hw, "Current CDCLK");
@@ -1786,8 +1791,12 @@ static void bxt_sanitize_cdclk(struct drm_i915_private *dev_priv)
expected = skl_cdclk_decimal(cdclk);

/* Figure out what CD2X divider we should be using for this cdclk */
- expected |= bxt_cdclk_cd2x_div_sel(dev_priv,
- dev_priv->cdclk.hw.cdclk,
+ if (has_cdclk_squasher(dev_priv))
+ clock = dev_priv->cdclk.hw.vco / 2;
+ else
+ clock = dev_priv->cdclk.hw.cdclk;
+
+ expected |= bxt_cdclk_cd2x_div_sel(dev_priv, clock,
dev_priv->cdclk.hw.vco);

/*
--
2.27.0