drm/radeon: atombios hw i2c fixes
These fixes make writes work properly. Previously
only reads worked. Note that this feature is off
by default.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c b/drivers/gpu/drm/radeon/atombios_i2c.c
index 2ca389d..deaf98c 100644
--- a/drivers/gpu/drm/radeon/atombios_i2c.c
+++ b/drivers/gpu/drm/radeon/atombios_i2c.c
@@ -32,7 +32,7 @@
#define TARGET_HW_I2C_CLOCK 50
/* these are a limitation of ProcessI2cChannelTransaction not the hw */
-#define ATOM_MAX_HW_I2C_WRITE 2
+#define ATOM_MAX_HW_I2C_WRITE 3
#define ATOM_MAX_HW_I2C_READ 255
static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
@@ -52,20 +52,24 @@
if (flags & HW_I2C_WRITE) {
if (num > ATOM_MAX_HW_I2C_WRITE) {
- DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 2)\n", num);
+ DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);
return -EINVAL;
}
- memcpy(&out, buf, num);
+ args.ucRegIndex = buf[0];
+ if (num > 1)
+ memcpy(&out, &buf[1], num - 1);
args.lpI2CDataOut = cpu_to_le16(out);
} else {
if (num > ATOM_MAX_HW_I2C_READ) {
DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
return -EINVAL;
}
+ args.ucRegIndex = 0;
+ args.lpI2CDataOut = 0;
}
+ args.ucFlag = flags;
args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
- args.ucRegIndex = 0;
args.ucTransBytes = num;
args.ucSlaveAddr = slave_addr << 1;
args.ucLineNumber = chan->rec.i2c_id;