[PATCH v3 12/15] drm/i915: Band Gap WA

Jani Nikula
2013-08-27T12:11:28Z

From: Shobhit Kumar <shobhit.kumar@intel.com>

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>
---
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 263c8d2..674fd49 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));
--
1.7.9.5