[Intel-gfx] [PATCH 3/4] drm/i915: add functions to disable and restore LCPLL
Paulo Zanoni
przanoni at gmail.com
Tue Jul 23 16:19:26 CEST 2013
From: Paulo Zanoni <paulo.r.zanoni at intel.com>
For now there are no callers, but these functions are going to be
needed for the code that allows Package C8+. Other future features may
also require this code.
Also merge the commit which introduced assert_can_disable_lcpll and
had the following commit message:
Most of the hardware needs to be disabled before LCPLL is disabled, so
let's add a function to assert some of items listed in the "Display
Sequences for LCPLL disabling" documentation.
The idea is that hsw_disable_lcpll should not disable the hardware,
the callers need to take care of calling hsw_disable_lcpll only once
everything is already disabled.
v2: - Rebase.
- Fix D_COMP wait timeout.
v3: - Use wait_for_atomic_use (Ben)
- Remove/add a useless/needed POSTING_READ (Ben)
- Early return in case LCPLL is already restored (Ben)
- Add ndelay(100) (Ben)
v4: - Merge the commit that added assert_can_disable_lcpll (Ben)
- Add interrupt assertions (Ben)
Reviewed-by: Ben Widawsky <ben at bwidawsk.net>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 15 ++++
drivers/gpu/drm/i915/intel_display.c | 136 +++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_drv.h | 3 +
3 files changed, 154 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0dfcbad..6caa748 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2261,6 +2261,8 @@
#define BLC_PWM_CPU_CTL2 0x48250
#define BLC_PWM_CPU_CTL 0x48254
+#define HSW_BLC_PWM2_CTL 0x48350
+
/* PCH CTL1 is totally different, all but the below bits are reserved. CTL2 is
* like the normal CTL from gen4 and earlier. Hooray for confusing naming. */
#define BLC_PWM_PCH_CTL1 0xc8250
@@ -2269,6 +2271,12 @@
#define BLM_PCH_POLARITY (1 << 29)
#define BLC_PWM_PCH_CTL2 0xc8254
+#define UTIL_PIN_CTL 0x48400
+#define UTIL_PIN_ENABLE (1 << 31)
+
+#define PCH_GTC_CTL 0xe7000
+#define PCH_GTC_ENABLE (1 << 31)
+
/* TV port control */
#define TV_CTL 0x68000
/** Enables the TV encoder */
@@ -5009,7 +5017,14 @@
#define LCPLL_CLK_FREQ_450 (0<<26)
#define LCPLL_CD_CLOCK_DISABLE (1<<25)
#define LCPLL_CD2X_CLOCK_DISABLE (1<<23)
+#define LCPLL_POWER_DOWN_ALLOW (1<<22)
#define LCPLL_CD_SOURCE_FCLK (1<<21)
+#define LCPLL_CD_SOURCE_FCLK_DONE (1<<19)
+
+#define D_COMP (MCHBAR_MIRROR_BASE_SNB + 0x5F0C)
+#define D_COMP_RCOMP_IN_PROGRESS (1<<9)
+#define D_COMP_COMP_FORCE (1<<8)
+#define D_COMP_COMP_DISABLE (1<<0)
/* Pipe WM_LINETIME - watermark line time */
#define PIPE_WM_LINETIME_A 0x45270
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index deee650d..0b0696a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5922,6 +5922,142 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
return true;
}
+static void assert_can_disable_lcpll(struct drm_i915_private *dev_priv)
+{
+ struct drm_device *dev = dev_priv->dev;
+ struct intel_ddi_plls *plls = &dev_priv->ddi_plls;
+ struct intel_crtc *crtc;
+ unsigned long irqflags;
+ uint32_t val, pch_hpd_mask;
+
+ pch_hpd_mask = SDE_PORTB_HOTPLUG_CPT | SDE_PORTC_HOTPLUG_CPT;
+ if (!HAS_LP_PCH(dev_priv))
+ pch_hpd_mask |= SDE_PORTD_HOTPLUG_CPT | SDE_CRT_HOTPLUG_CPT;
+
+ list_for_each_entry(crtc, &dev->mode_config.crtc_list, base.head)
+ WARN(crtc->base.enabled, "CRTC for pipe %c enabled\n",
+ pipe_name(crtc->pipe));
+
+ WARN(I915_READ(HSW_PWR_WELL_DRIVER), "Power well on\n");
+ WARN(plls->spll_refcount, "SPLL enabled\n");
+ WARN(plls->wrpll1_refcount, "WRPLL1 enabled\n");
+ WARN(plls->wrpll2_refcount, "WRPLL2 enabled\n");
+ WARN(I915_READ(PCH_PP_STATUS) & PP_ON, "Panel power on\n");
+ WARN(I915_READ(BLC_PWM_CPU_CTL2) & BLM_PWM_ENABLE,
+ "CPU PWM1 enabled\n");
+ WARN(I915_READ(HSW_BLC_PWM2_CTL) & BLM_PWM_ENABLE,
+ "CPU PWM2 enabled\n");
+ WARN(I915_READ(BLC_PWM_PCH_CTL1) & BLM_PCH_PWM_ENABLE,
+ "PCH PWM1 enabled\n");
+ WARN(I915_READ(UTIL_PIN_CTL) & UTIL_PIN_ENABLE,
+ "Utility pin enabled\n");
+ WARN(I915_READ(PCH_GTC_CTL) & PCH_GTC_ENABLE, "PCH GTC enabled\n");
+
+ spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+ val = I915_READ(DEIMR);
+ WARN((val & ~DE_PCH_EVENT_IVB) != val,
+ "Unexpected DEIMR bits enabled: 0x%x\n", val);
+ val = I915_READ(SDEIMR);
+ WARN((val & ~pch_hpd_mask) != val,
+ "Unexpected SDEIMR bits enabled: 0x%x\n", val);
+ spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+}
+
+/*
+ * This function implements pieces of two sequences from BSpec:
+ * - Sequence for display software to disable LCPLL
+ * - Sequence for display software to allow package C8+
+ * The steps implemented here are just the steps that actually touch the LCPLL
+ * register. Callers should take care of disabling all the display engine
+ * functions, doing the mode unset, fixing interrupts, etc.
+ */
+void hsw_disable_lcpll(struct drm_i915_private *dev_priv,
+ bool switch_to_fclk, bool allow_power_down)
+{
+ uint32_t val;
+
+ assert_can_disable_lcpll(dev_priv);
+
+ val = I915_READ(LCPLL_CTL);
+
+ if (switch_to_fclk) {
+ val |= LCPLL_CD_SOURCE_FCLK;
+ I915_WRITE(LCPLL_CTL, val);
+
+ if (wait_for_atomic_us(I915_READ(LCPLL_CTL) &
+ LCPLL_CD_SOURCE_FCLK_DONE, 1))
+ DRM_ERROR("Switching to FCLK failed\n");
+
+ val = I915_READ(LCPLL_CTL);
+ }
+
+ val |= LCPLL_PLL_DISABLE;
+ I915_WRITE(LCPLL_CTL, val);
+ POSTING_READ(LCPLL_CTL);
+
+ if (wait_for((I915_READ(LCPLL_CTL) & LCPLL_PLL_LOCK) == 0, 1))
+ DRM_ERROR("LCPLL still locked\n");
+
+ val = I915_READ(D_COMP);
+ val |= D_COMP_COMP_DISABLE;
+ I915_WRITE(D_COMP, val);
+ POSTING_READ(D_COMP);
+ ndelay(100);
+
+ if (wait_for((I915_READ(D_COMP) & D_COMP_RCOMP_IN_PROGRESS) == 0, 1))
+ DRM_ERROR("D_COMP RCOMP still in progress\n");
+
+ if (allow_power_down) {
+ val = I915_READ(LCPLL_CTL);
+ val |= LCPLL_POWER_DOWN_ALLOW;
+ I915_WRITE(LCPLL_CTL, val);
+ POSTING_READ(LCPLL_CTL);
+ }
+}
+
+/*
+ * Fully restores LCPLL, disallowing power down and switching back to LCPLL
+ * source.
+ */
+void hsw_restore_lcpll(struct drm_i915_private *dev_priv)
+{
+ uint32_t val;
+
+ val = I915_READ(LCPLL_CTL);
+
+ if ((val & (LCPLL_PLL_LOCK | LCPLL_PLL_DISABLE | LCPLL_CD_SOURCE_FCLK |
+ LCPLL_POWER_DOWN_ALLOW)) == LCPLL_PLL_LOCK)
+ return;
+
+ if (val & LCPLL_POWER_DOWN_ALLOW) {
+ val &= ~LCPLL_POWER_DOWN_ALLOW;
+ I915_WRITE(LCPLL_CTL, val);
+ }
+
+ val = I915_READ(D_COMP);
+ val |= D_COMP_COMP_FORCE;
+ val &= ~D_COMP_COMP_DISABLE;
+ I915_WRITE(D_COMP, val);
+ I915_READ(D_COMP);
+
+ val = I915_READ(LCPLL_CTL);
+ val &= ~LCPLL_PLL_DISABLE;
+ I915_WRITE(LCPLL_CTL, val);
+
+ if (wait_for(I915_READ(LCPLL_CTL) & LCPLL_PLL_LOCK, 5))
+ DRM_ERROR("LCPLL not locked yet\n");
+
+ if (val & LCPLL_CD_SOURCE_FCLK) {
+ val = I915_READ(LCPLL_CTL);
+ val &= ~LCPLL_CD_SOURCE_FCLK;
+ I915_WRITE(LCPLL_CTL, val);
+
+ if (wait_for_atomic_us((I915_READ(LCPLL_CTL) &
+ LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1))
+ DRM_ERROR("Switching back to LCPLL failed\n");
+ }
+}
+
static void haswell_modeset_global_resources(struct drm_device *dev)
{
bool enable = false;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 31087ff..3fbe80b 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -838,5 +838,8 @@ extern bool intel_set_pch_fifo_underrun_reporting(struct drm_device *dev,
extern void intel_edp_psr_enable(struct intel_dp *intel_dp);
extern void intel_edp_psr_disable(struct intel_dp *intel_dp);
extern void intel_edp_psr_update(struct drm_device *dev);
+extern void hsw_disable_lcpll(struct drm_i915_private *dev_priv,
+ bool switch_to_fclk, bool allow_power_down);
+extern void hsw_restore_lcpll(struct drm_i915_private *dev_priv);
#endif /* __INTEL_DRV_H__ */
--
1.8.1.2
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