From: Gwan-gyeong Mun <gwan-gyeong.mun@xxxxxxxxx>
CDCLK crawl feature allows to change CDCLK frequency
without disabling the actual PLL and doesn't require
a full modeset.
Cc: Mika Kahola <mika.kahola@xxxxxxxxx>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@xxxxxxxxx>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_cdclk.c | 72 +++++++++++++++++++---
drivers/gpu/drm/i915/i915_reg.h | 2 +
2 files changed, 65 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
index 618a9e1e2b0c..b9abed82328c 100644
--- a/drivers/gpu/drm/i915/display/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
@@ -1548,6 +1548,35 @@ static void cnl_cdclk_pll_enable(struct drm_i915_private *dev_priv, int vco)
dev_priv->cdclk.hw.vco = vco;
}
+static bool has_cdclk_crawl(struct drm_i915_private *i915)
+{
+ return IS_ALDERLAKE_P(i915);
+}
+
+static void gen13_cdclk_pll_crawl(struct drm_i915_private *dev_priv, int vco)
+{
+ int ratio = DIV_ROUND_CLOSEST(vco, dev_priv->cdclk.hw.ref);
+ u32 val;
+
+ /* Write PLL ratio without disabling */
+ val = CNL_CDCLK_PLL_RATIO(ratio) | BXT_DE_PLL_PLL_ENABLE;
+ intel_de_write(dev_priv, BXT_DE_PLL_ENABLE, val);
+
+ /* Submit freq change request */
+ val |= BXT_DE_PLL_FREQ_REQ;
+ intel_de_write(dev_priv, BXT_DE_PLL_ENABLE, val);
+
+ /* Timeout 200us */
+ if (intel_de_wait_for_set(dev_priv, BXT_DE_PLL_ENABLE,
+ BXT_DE_PLL_LOCK | BXT_DE_PLL_FREQ_REQ_ACK, 1))
+ DRM_ERROR("timeout waiting for FREQ change request ack\n");
+
+ val &= ~BXT_DE_PLL_FREQ_REQ;
+ intel_de_write(dev_priv, BXT_DE_PLL_ENABLE, val);
+
+ dev_priv->cdclk.hw.vco = vco;
+}
+
static u32 bxt_cdclk_cd2x_pipe(struct drm_i915_private *dev_priv, enum pipe pipe)
{
if (DISPLAY_VER(dev_priv) >= 12) {
@@ -1620,14 +1649,16 @@ static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
return;
}
- if (DISPLAY_VER(dev_priv) >= 11 || IS_CANNONLAKE(dev_priv)) {
+ if (has_cdclk_crawl(dev_priv) && dev_priv->cdclk.hw.vco > 0 && vco > 0) {
+ if (dev_priv->cdclk.hw.vco != vco)
+ gen13_cdclk_pll_crawl(dev_priv, vco);
+ } else if (DISPLAY_VER(dev_priv) >= 11 || IS_CANNONLAKE(dev_priv)) {
if (dev_priv->cdclk.hw.vco != 0 &&
dev_priv->cdclk.hw.vco != vco)
cnl_cdclk_pll_disable(dev_priv);
if (dev_priv->cdclk.hw.vco != vco)
cnl_cdclk_pll_enable(dev_priv, vco);
-
} else {
if (dev_priv->cdclk.hw.vco != 0 &&
dev_priv->cdclk.hw.vco != vco)
@@ -1820,6 +1851,28 @@ void intel_cdclk_uninit_hw(struct drm_i915_private *i915)
skl_cdclk_uninit_hw(i915);
}
+static bool intel_cdclk_can_crawl(struct drm_i915_private *dev_priv,
+ const struct intel_cdclk_config *a,
+ const struct intel_cdclk_config *b)
+{
+ int a_div, b_div;
+
+ if (!has_cdclk_crawl(dev_priv))
+ return false;
+
+ /*
+ * The vco and cd2x divider will change independently
+ * from each, so we disallow cd2x change when crawling.
+ */
+ a_div = DIV_ROUND_CLOSEST(a->vco, a->cdclk);
+ b_div = DIV_ROUND_CLOSEST(b->vco, b->cdclk);
+
+ return a->vco != 0 && b->vco != 0 &&
+ a->vco != b->vco &&
+ a_div == b_div &&
+ a->ref == b->ref;
+}
+
/**
* intel_cdclk_needs_modeset - Determine if changong between the CDCLK
* configurations requires a modeset on all pipes
@@ -2475,7 +2528,7 @@ int intel_modeset_calc_cdclk(struct intel_atomic_state *state)
struct drm_i915_private *dev_priv = to_i915(state->base.dev);
const struct intel_cdclk_state *old_cdclk_state;
struct intel_cdclk_state *new_cdclk_state;
- enum pipe pipe;
+ enum pipe pipe = INVALID_PIPE;
int ret;
new_cdclk_state = intel_atomic_get_cdclk_state(state);
@@ -2527,15 +2580,18 @@ int intel_modeset_calc_cdclk(struct intel_atomic_state *state)
if (drm_atomic_crtc_needs_modeset(&crtc_state->uapi))
pipe = INVALID_PIPE;
- } else {
- pipe = INVALID_PIPE;
}
- if (pipe != INVALID_PIPE) {
+ if (intel_cdclk_can_crawl(dev_priv,
+ &old_cdclk_state->actual,
+ &new_cdclk_state->actual)) {
+ drm_dbg_kms(&dev_priv->drm,
+ "Can change cdclk via crawl\n");
+ } else if (pipe != INVALID_PIPE) {
new_cdclk_state->pipe = pipe;
drm_dbg_kms(&dev_priv->drm,
- "Can change cdclk with pipe %c active\n",
+ "Can change cdclk cd2x divider with pipe %c active\n",
pipe_name(pipe));
} else if (intel_cdclk_needs_modeset(&old_cdclk_state->actual,
&new_cdclk_state->actual)) {
@@ -2544,8 +2600,6 @@ int intel_modeset_calc_cdclk(struct intel_atomic_state *state)
if (ret)
return ret;
- new_cdclk_state->pipe = INVALID_PIPE;
-
drm_dbg_kms(&dev_priv->drm,
"Modeset required for cdclk change\n");
}
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 3b58067a873c..1d1176d1799d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -11157,6 +11157,8 @@ enum skl_power_gate {
#define BXT_DE_PLL_ENABLE _MMIO(0x46070)
#define BXT_DE_PLL_PLL_ENABLE (1 << 31)
#define BXT_DE_PLL_LOCK (1 << 30)
+#define BXT_DE_PLL_FREQ_REQ (1 << 23)
+#define BXT_DE_PLL_FREQ_REQ_ACK (1 << 22)
#define CNL_CDCLK_PLL_RATIO(x) (x)
#define CNL_CDCLK_PLL_RATIO_MASK 0xff
--
2.24.1.485.gad05a3d8e5
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