- unsigned retry;
-
- msg[0] = address;
- msg[1] = address >> 8;
- msg[2] = DP_AUX_NATIVE_READ << 4;
- msg[3] = (msg_bytes << 4) | (recv_bytes - 1);
-
- for (retry = 0; retry < 7; retry++) {
- ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
- msg, msg_bytes, recv, recv_bytes, delay, &ack);
- if (ret == -EBUSY)
- continue;
- else if (ret < 0)
- return ret;
- ack >>= 4;
- if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_ACK)
- return ret;
- else if ((ack & DP_AUX_NATIVE_REPLY_MASK) == DP_AUX_NATIVE_REPLY_DEFER)
- usleep_range(400, 500);
- else if (ret == 0)
- return -EPROTO;
- else
- return -EIO;
+ u8 tx_buf[20];
+ size_t tx_size;
+ u8 ack, delay = 0;
+
+ if (WARN_ON(msg->size > 16))
+ return -E2BIG;
+
+ tx_buf[0] = msg->address & 0xff;
+ tx_buf[1] = msg->address >> 8;
+ tx_buf[2] = msg->request << 4;
+ tx_buf[3] = msg->size - 1;
+
+ switch (msg->request & ~DP_AUX_I2C_MOT) {
+ case DP_AUX_NATIVE_WRITE:
+ case DP_AUX_I2C_WRITE:
+ tx_size = HEADER_SIZE + msg->size;
+ tx_buf[3] |= tx_size << 4;
+ memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
+ ret = radeon_process_aux_ch(chan,
+ tx_buf, tx_size, NULL, 0, delay, &ack);
+ if (ret >= 0)
+ /* Return payload size. */
+ ret = msg->size;
+ break;
+ case DP_AUX_NATIVE_READ:
+ case DP_AUX_I2C_READ:
+ tx_size = HEADER_SIZE;
+ tx_buf[3] |= tx_size << 4;
+ ret = radeon_process_aux_ch(chan,
+ tx_buf, tx_size, msg->buffer, msg->size, delay, &ack);
+ break;
+ default:
+ ret = -EINVAL;
+ break;