blob: 24666d3deb763fc56fd2b9a73f9935010a59e5c9 [file] [log] [blame]
From 6e84b1679e29d0cf5e80f61370af2d4d506f02ef Mon Sep 17 00:00:00 2001
From: Shobhit Kumar <shobhit.kumar@intel.com>
Date: Tue, 27 Aug 2013 15:12:24 +0300
Subject: drm/i915: Band Gap WA
Note: No one seems to have docs for this, so this patch here is just
unreviewed black magic :(
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: ymohanma <yogesh.mohan.marimuthu@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
[danvet: Add note about the doc situation.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit 4ce8c9a720c566a4ce7b782ddd5df90d66f0ba85)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
drivers/gpu/drm/i915/intel_dsi.c | 48 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 263c8d2603b6..674fd4989b45 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -37,6 +37,51 @@
static const struct intel_dsi_device intel_dsi_devices[] = {
};
+
+static void vlv_cck_modify(struct drm_i915_private *dev_priv, u32 reg, u32 val,
+ u32 mask)
+{
+ u32 tmp = vlv_cck_read(dev_priv, reg);
+ tmp &= ~mask;
+ tmp |= val;
+ vlv_cck_write(dev_priv, reg, tmp);
+}
+
+static void band_gap_wa(struct drm_i915_private *dev_priv)
+{
+ mutex_lock(&dev_priv->dpio_lock);
+
+ /* Enable bandgap fix in GOP driver */
+ vlv_cck_modify(dev_priv, 0x6D, 0x00010000, 0x00030000);
+ msleep(20);
+ vlv_cck_modify(dev_priv, 0x6E, 0x00010000, 0x00030000);
+ msleep(20);
+ vlv_cck_modify(dev_priv, 0x6F, 0x00010000, 0x00030000);
+ msleep(20);
+ vlv_cck_modify(dev_priv, 0x00, 0x00008000, 0x00008000);
+ msleep(20);
+ vlv_cck_modify(dev_priv, 0x00, 0x00000000, 0x00008000);
+ msleep(20);
+
+ /* Turn Display Trunk on */
+ vlv_cck_modify(dev_priv, 0x6B, 0x00020000, 0x00030000);
+ msleep(20);
+
+ vlv_cck_modify(dev_priv, 0x6C, 0x00020000, 0x00030000);
+ msleep(20);
+
+ vlv_cck_modify(dev_priv, 0x6D, 0x00020000, 0x00030000);
+ msleep(20);
+ vlv_cck_modify(dev_priv, 0x6E, 0x00020000, 0x00030000);
+ msleep(20);
+ vlv_cck_modify(dev_priv, 0x6F, 0x00020000, 0x00030000);
+
+ mutex_unlock(&dev_priv->dpio_lock);
+
+ /* Need huge delay, otherwise clock is not stable */
+ msleep(100);
+}
+
static struct intel_dsi *intel_attached_dsi(struct drm_connector *connector)
{
return container_of(intel_attached_encoder(connector),
@@ -310,6 +355,9 @@ static void intel_dsi_mode_set(struct intel_encoder *intel_encoder)
/* Update the DSI PLL */
vlv_enable_dsi_pll(intel_encoder);
+ /* XXX: Location of the call */
+ band_gap_wa(dev_priv);
+
/* escape clock divider, 20MHz, shared for A and C. device ready must be
* off when doing this! txclkesc? */
tmp = I915_READ(MIPI_CTRL(0));
--
1.8.5.rc3