drm/i915: use GMBUS to manage i2c links
Use the GMBUS interface rather than direct bit banging to grab the EDID
over DDC (and for other forms of auxiliary communication with external
display controllers). The hope is that this method will be much faster
and more reliable than bit banging for fetching EDIDs from buggy monitors
or through switches, though we still preserve the bit banging as a
fallback in case GMBUS fails.
Based on an original patch by Jesse Barnes.
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/dvo_ivch.c b/drivers/gpu/drm/i915/dvo_ivch.c
index a2ec3f4..a12ed94 100644
--- a/drivers/gpu/drm/i915/dvo_ivch.c
+++ b/drivers/gpu/drm/i915/dvo_ivch.c
@@ -167,7 +167,6 @@
{
struct ivch_priv *priv = dvo->dev_priv;
struct i2c_adapter *adapter = dvo->i2c_bus;
- struct intel_i2c_chan *i2cbus = container_of(adapter, struct intel_i2c_chan, adapter);
u8 out_buf[1];
u8 in_buf[2];
@@ -193,7 +192,7 @@
out_buf[0] = addr;
- if (i2c_transfer(&i2cbus->adapter, msgs, 3) == 3) {
+ if (i2c_transfer(adapter, msgs, 3) == 3) {
*data = (in_buf[1] << 8) | in_buf[0];
return true;
};
@@ -201,7 +200,7 @@
if (!priv->quiet) {
DRM_DEBUG_KMS("Unable to read register 0x%02x from "
"%s:%02x.\n",
- addr, i2cbus->adapter.name, dvo->slave_addr);
+ addr, adapter->name, dvo->slave_addr);
}
return false;
}
@@ -211,7 +210,6 @@
{
struct ivch_priv *priv = dvo->dev_priv;
struct i2c_adapter *adapter = dvo->i2c_bus;
- struct intel_i2c_chan *i2cbus = container_of(adapter, struct intel_i2c_chan, adapter);
u8 out_buf[3];
struct i2c_msg msg = {
.addr = dvo->slave_addr,
@@ -224,12 +222,12 @@
out_buf[1] = data & 0xff;
out_buf[2] = data >> 8;
- if (i2c_transfer(&i2cbus->adapter, &msg, 1) == 1)
+ if (i2c_transfer(adapter, &msg, 1) == 1)
return true;
if (!priv->quiet) {
DRM_DEBUG_KMS("Unable to write register 0x%02x to %s:%d.\n",
- addr, i2cbus->adapter.name, dvo->slave_addr);
+ addr, adapter->name, dvo->slave_addr);
}
return false;