drm/radeon/kms: add support for external tmds on legacy boards

[karo-tx-linux.git] / drivers / gpu / drm / radeon / radeon_i2c.c

diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
index e97a3912d99f3626414ef2a9a8dad336f28b0d11..6c645fb4dad87b56aaf155ff1980b443b1ba7a42 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_i2c.c
+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
@@ -212,3 +212,59 @@ struct drm_encoder *radeon_best_encoder(struct drm_connector *connector)
 {
        return NULL;
 }
+
+void radeon_i2c_sw_get_byte(struct radeon_i2c_chan *i2c_bus,
+                           u8 slave_addr,
+                           u8 addr,
+                           u8 *val)
+{
+       u8 out_buf[2];
+       u8 in_buf[2];
+       struct i2c_msg msgs[] = {
+               {
+                       .addr = slave_addr,
+                       .flags = 0,
+                       .len = 1,
+                       .buf = out_buf,
+               },
+               {
+                       .addr = slave_addr,
+                       .flags = I2C_M_RD,
+                       .len = 1,
+                       .buf = in_buf,
+               }
+       };
+
+       out_buf[0] = addr;
+       out_buf[1] = 0;
+
+       if (i2c_transfer(&i2c_bus->adapter, msgs, 2) == 2) {
+               *val = in_buf[0];
+               DRM_DEBUG("val = 0x%02x\n", *val);
+       } else {
+               DRM_ERROR("i2c 0x%02x 0x%02x read failed\n",
+                         addr, *val);
+       }
+}
+
+void radeon_i2c_sw_put_byte(struct radeon_i2c_chan *i2c_bus,
+                           u8 slave_addr,
+                           u8 addr,
+                           u8 val)
+{
+       uint8_t out_buf[2];
+       struct i2c_msg msg = {
+               .addr = slave_addr,
+               .flags = 0,
+               .len = 2,
+               .buf = out_buf,
+       };
+
+       out_buf[0] = addr;
+       out_buf[1] = val;
+
+       if (i2c_transfer(&i2c_bus->adapter, &msg, 1) != 1)
+               DRM_ERROR("i2c 0x%02x 0x%02x write failed\n",
+                         addr, val);
+}
+