From 4ce8c9a720c566a4ce7b782ddd5df90d66f0ba85 Mon Sep 17 00:00:00 2001 From: Shobhit Kumar Date: Tue, 27 Aug 2013 15:12:24 +0300 Subject: [PATCH] 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 Signed-off-by: ymohanma Signed-off-by: Jani Nikula [danvet: Add note about the doc situation.] Signed-off-by: Daniel Vetter --- 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)); -- 2.34.1