[PATCH] drm/i915: Enable digital port hotplug on PCH systems

From: Keith Packard
Date: Tue Sep 20 2011 - 11:47:29 EST


We were relying on the BIOS to set these bits, which doesn't always
happen.

Signed-off-by: Keith Packard <keithp@xxxxxxxxxx>
---

v2: set the hotplug bits in the irq post-install hook, just
like we do for pre-PCH hardware.

drivers/gpu/drm/i915/i915_irq.c | 24 ++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_reg.h | 5 ++++-
2 files changed, 28 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 9cbb0cd..c22823b 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1777,6 +1777,26 @@ static void ironlake_irq_preinstall(struct drm_device *dev)
POSTING_READ(SDEIER);
}

+/*
+ * Enable digital hotplug on the PCH, and configure the DP short pulse
+ * duration to 2ms (which is the minimum in the Display Port spec)
+ *
+ * This register is the same on all known PCH chips.
+ */
+
+static void ironlake_enable_pch_hotplug(struct drm_device *dev)
+{
+ drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+ u32 hotplug;
+
+ hotplug = I915_READ(PCH_PORT_HOTPLUG);
+ hotplug &= ~(PORTD_PULSE_DURATION_MASK|PORTC_PULSE_DURATION_MASK|PORTB_PULSE_DURATION_MASK);
+ hotplug |= PORTD_HOTPLUG_ENABLE | PORTD_PULSE_DURATION_2ms;
+ hotplug |= PORTC_HOTPLUG_ENABLE | PORTC_PULSE_DURATION_2ms;
+ hotplug |= PORTB_HOTPLUG_ENABLE | PORTB_PULSE_DURATION_2ms;
+ I915_WRITE(PCH_PORT_HOTPLUG, hotplug);
+}
+
static int ironlake_irq_postinstall(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
@@ -1839,6 +1859,8 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
I915_WRITE(SDEIER, hotplug_mask);
POSTING_READ(SDEIER);

+ ironlake_enable_pch_hotplug(dev);
+
if (IS_IRONLAKE_M(dev)) {
/* Clear & enable PCU event interrupts */
I915_WRITE(DEIIR, DE_PCU_EVENT);
@@ -1896,6 +1918,8 @@ static int ivybridge_irq_postinstall(struct drm_device *dev)
I915_WRITE(SDEIER, hotplug_mask);
POSTING_READ(SDEIER);

+ ironlake_enable_pch_hotplug(dev);
+
return 0;
}

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 542453f..b7fbb74 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2903,12 +2903,13 @@
#define SDEIER 0xc400c

/* digital port hotplug */
-#define PCH_PORT_HOTPLUG 0xc4030
+#define PCH_PORT_HOTPLUG 0xc4030 /* SHOTPLUG_CTL */
#define PORTD_HOTPLUG_ENABLE (1 << 20)
#define PORTD_PULSE_DURATION_2ms (0)
#define PORTD_PULSE_DURATION_4_5ms (1 << 18)
#define PORTD_PULSE_DURATION_6ms (2 << 18)
#define PORTD_PULSE_DURATION_100ms (3 << 18)
+#define PORTD_PULSE_DURATION_MASK (3 << 18)
#define PORTD_HOTPLUG_NO_DETECT (0)
#define PORTD_HOTPLUG_SHORT_DETECT (1 << 16)
#define PORTD_HOTPLUG_LONG_DETECT (1 << 17)
@@ -2917,6 +2918,7 @@
#define PORTC_PULSE_DURATION_4_5ms (1 << 10)
#define PORTC_PULSE_DURATION_6ms (2 << 10)
#define PORTC_PULSE_DURATION_100ms (3 << 10)
+#define PORTC_PULSE_DURATION_MASK (3 << 10)
#define PORTC_HOTPLUG_NO_DETECT (0)
#define PORTC_HOTPLUG_SHORT_DETECT (1 << 8)
#define PORTC_HOTPLUG_LONG_DETECT (1 << 9)
@@ -2925,6 +2927,7 @@
#define PORTB_PULSE_DURATION_4_5ms (1 << 2)
#define PORTB_PULSE_DURATION_6ms (2 << 2)
#define PORTB_PULSE_DURATION_100ms (3 << 2)
+#define PORTB_PULSE_DURATION_MASK (3 << 2)
#define PORTB_HOTPLUG_NO_DETECT (0)
#define PORTB_HOTPLUG_SHORT_DETECT (1 << 0)
#define PORTB_HOTPLUG_LONG_DETECT (1 << 1)
--
1.7.6.3

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