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>
This commit is contained in:
Chris Wilson
2010-07-20 15:44:45 -07:00
부모 373a3cf744
커밋 f899fc64cd
21개의 변경된 파일444개의 추가작업 그리고 422개의 파일을 삭제

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@@ -94,7 +94,6 @@ static bool tfp410_readb(struct intel_dvo_device *dvo, int addr, uint8_t *ch)
{
struct tfp410_priv *tfp = 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[2];
u8 in_buf[2];
@@ -116,14 +115,14 @@ static bool tfp410_readb(struct intel_dvo_device *dvo, int addr, uint8_t *ch)
out_buf[0] = addr;
out_buf[1] = 0;
if (i2c_transfer(&i2cbus->adapter, msgs, 2) == 2) {
if (i2c_transfer(adapter, msgs, 2) == 2) {
*ch = in_buf[0];
return true;
};
if (!tfp->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;
}
@@ -132,7 +131,6 @@ static bool tfp410_writeb(struct intel_dvo_device *dvo, int addr, uint8_t ch)
{
struct tfp410_priv *tfp = dvo->dev_priv;
struct i2c_adapter *adapter = dvo->i2c_bus;
struct intel_i2c_chan *i2cbus = container_of(adapter, struct intel_i2c_chan, adapter);
uint8_t out_buf[2];
struct i2c_msg msg = {
.addr = dvo->slave_addr,
@@ -144,12 +142,12 @@ static bool tfp410_writeb(struct intel_dvo_device *dvo, int addr, uint8_t ch)
out_buf[0] = addr;
out_buf[1] = ch;
if (i2c_transfer(&i2cbus->adapter, &msg, 1) == 1)
if (i2c_transfer(adapter, &msg, 1) == 1)
return true;
if (!tfp->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;