drm/i915: add PLL enable/disable functions
For pre-ILK only. Saves some code in the CRTC enable/disable functions
and allows us to check for pipe and panel status at enable/disable time.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 491ac56..607bd2f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1110,18 +1110,22 @@
pipe ? 'B' : 'A');
}
-static void assert_pipe_enabled(struct drm_i915_private *dev_priv,
- enum pipe pipe)
+static void assert_pipe(struct drm_i915_private *dev_priv,
+ enum pipe pipe, bool state)
{
int reg;
u32 val;
+ bool cur_state;
reg = PIPECONF(pipe);
val = I915_READ(reg);
- WARN(!(val & PIPECONF_ENABLE),
- "pipe %c assertion failure, should be active but is disabled\n",
- pipe ? 'B' : 'A');
+ cur_state = !!(val & PIPECONF_ENABLE);
+ WARN(cur_state != state,
+ "pipe %c assertion failure (expected %s, current %s)\n",
+ pipe ? 'B' : 'A', state_string(state), state_string(cur_state));
}
+#define assert_pipe_enabled(d, p) assert_pipe(d, p, true)
+#define assert_pipe_disabled(d, p) assert_pipe(d, p, false)
static void assert_plane_enabled(struct drm_i915_private *dev_priv,
enum plane plane)
@@ -1156,6 +1160,73 @@
}
/**
+ * intel_enable_pll - enable a PLL
+ * @dev_priv: i915 private structure
+ * @pipe: pipe PLL to enable
+ *
+ * Enable @pipe's PLL so we can start pumping pixels from a plane. Check to
+ * make sure the PLL reg is writable first though, since the panel write
+ * protect mechanism may be enabled.
+ *
+ * Note! This is for pre-ILK only.
+ */
+static void intel_enable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
+{
+ int reg;
+ u32 val;
+
+ /* No really, not for ILK+ */
+ BUG_ON(dev_priv->info->gen >= 5);
+
+ /* PLL is protected by panel, make sure we can write it */
+ if (IS_MOBILE(dev_priv->dev) && !IS_I830(dev_priv->dev))
+ assert_panel_unlocked(dev_priv, pipe);
+
+ reg = DPLL(pipe);
+ val = I915_READ(reg);
+ val |= DPLL_VCO_ENABLE;
+
+ /* We do this three times for luck */
+ I915_WRITE(reg, val);
+ POSTING_READ(reg);
+ udelay(150); /* wait for warmup */
+ I915_WRITE(reg, val);
+ POSTING_READ(reg);
+ udelay(150); /* wait for warmup */
+ I915_WRITE(reg, val);
+ POSTING_READ(reg);
+ udelay(150); /* wait for warmup */
+}
+
+/**
+ * intel_disable_pll - disable a PLL
+ * @dev_priv: i915 private structure
+ * @pipe: pipe PLL to disable
+ *
+ * Disable the PLL for @pipe, making sure the pipe is off first.
+ *
+ * Note! This is for pre-ILK only.
+ */
+static void intel_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
+{
+ int reg;
+ u32 val;
+
+ /* Don't disable pipe A or pipe A PLLs if needed */
+ if (pipe == PIPE_A && (dev_priv->quirks & QUIRK_PIPEA_FORCE))
+ return;
+
+ /* Make sure the pipe isn't still relying on us */
+ assert_pipe_disabled(dev_priv, pipe);
+
+ reg = DPLL(pipe);
+ val = I915_READ(reg);
+ val &= ~DPLL_VCO_ENABLE;
+ I915_WRITE(reg, val);
+ POSTING_READ(reg);
+}
+
+/**
* intel_enable_pipe - enable a pipe, assertiing requirements
* @dev_priv: i915 private structure
* @pipe: pipe to enable
@@ -2559,7 +2630,6 @@
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
int pipe = intel_crtc->pipe;
int plane = intel_crtc->plane;
- u32 reg, temp;
if (intel_crtc->active)
return;
@@ -2567,29 +2637,7 @@
intel_crtc->active = true;
intel_update_watermarks(dev);
- /* Enable the DPLL */
- reg = DPLL(pipe);
- temp = I915_READ(reg);
- if ((temp & DPLL_VCO_ENABLE) == 0) {
- I915_WRITE(reg, temp);
-
- /* Wait for the clocks to stabilize. */
- POSTING_READ(reg);
- udelay(150);
-
- I915_WRITE(reg, temp | DPLL_VCO_ENABLE);
-
- /* Wait for the clocks to stabilize. */
- POSTING_READ(reg);
- udelay(150);
-
- I915_WRITE(reg, temp | DPLL_VCO_ENABLE);
-
- /* Wait for the clocks to stabilize. */
- POSTING_READ(reg);
- udelay(150);
- }
-
+ intel_enable_pll(dev_priv, pipe);
intel_enable_pipe(dev_priv, pipe);
intel_enable_plane(dev_priv, plane, pipe);
@@ -2608,7 +2656,6 @@
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
int pipe = intel_crtc->pipe;
int plane = intel_crtc->plane;
- u32 reg, temp;
if (!intel_crtc->active)
return;
@@ -2624,24 +2671,9 @@
dev_priv->display.disable_fbc(dev);
intel_disable_plane(dev_priv, plane, pipe);
-
- /* Don't disable pipe A or pipe A PLLs if needed */
- if (pipe == 0 && (dev_priv->quirks & QUIRK_PIPEA_FORCE))
- goto done;
-
intel_disable_pipe(dev_priv, pipe);
+ intel_disable_pll(dev_priv, pipe);
- reg = DPLL(pipe);
- temp = I915_READ(reg);
- if (temp & DPLL_VCO_ENABLE) {
- I915_WRITE(reg, temp & ~DPLL_VCO_ENABLE);
-
- /* Wait for the clocks to turn off. */
- POSTING_READ(reg);
- udelay(150);
- }
-
-done:
intel_crtc->active = false;
intel_update_fbc(dev);
intel_update_watermarks(dev);