#define MC_PMG_CMD_MRS2                                 0x2b5c
 #define MC_SEQ_PMG_CMD_MRS2_LP                          0x2b60
 
+#define AUX_CONTROL                                    0x6200
+#define        AUX_EN                                  (1 << 0)
+#define        AUX_LS_READ_EN                          (1 << 8)
+#define        AUX_LS_UPDATE_DISABLE(x)                (((x) & 0x1) << 12)
+#define        AUX_HPD_DISCON(x)                       (((x) & 0x1) << 16)
+#define        AUX_DET_EN                              (1 << 18)
+#define        AUX_HPD_SEL(x)                          (((x) & 0x7) << 20)
+#define        AUX_IMPCAL_REQ_EN                       (1 << 24)
+#define        AUX_TEST_MODE                           (1 << 28)
+#define        AUX_DEGLITCH_EN                         (1 << 29)
+#define AUX_SW_CONTROL                                 0x6204
+#define        AUX_SW_GO                               (1 << 0)
+#define        AUX_LS_READ_TRIG                        (1 << 2)
+#define        AUX_SW_START_DELAY(x)                   (((x) & 0xf) << 4)
+#define        AUX_SW_WR_BYTES(x)                      (((x) & 0x1f) << 16)
+
+#define AUX_SW_INTERRUPT_CONTROL                       0x620c
+#define        AUX_SW_DONE_INT                         (1 << 0)
+#define        AUX_SW_DONE_ACK                         (1 << 1)
+#define        AUX_SW_DONE_MASK                        (1 << 2)
+#define        AUX_SW_LS_DONE_INT                      (1 << 4)
+#define        AUX_SW_LS_DONE_MASK                     (1 << 6)
+#define AUX_SW_STATUS                                  0x6210
+#define        AUX_SW_DONE                             (1 << 0)
+#define        AUX_SW_REQ                              (1 << 1)
+#define        AUX_SW_RX_TIMEOUT_STATE(x)              (((x) & 0x7) << 4)
+#define        AUX_SW_RX_TIMEOUT                       (1 << 7)
+#define        AUX_SW_RX_OVERFLOW                      (1 << 8)
+#define        AUX_SW_RX_HPD_DISCON                    (1 << 9)
+#define        AUX_SW_RX_PARTIAL_BYTE                  (1 << 10)
+#define        AUX_SW_NON_AUX_MODE                     (1 << 11)
+#define        AUX_SW_RX_MIN_COUNT_VIOL                (1 << 12)
+#define        AUX_SW_RX_INVALID_STOP                  (1 << 14)
+#define        AUX_SW_RX_SYNC_INVALID_L                (1 << 17)
+#define        AUX_SW_RX_SYNC_INVALID_H                (1 << 18)
+#define        AUX_SW_RX_INVALID_START                 (1 << 19)
+#define        AUX_SW_RX_RECV_NO_DET                   (1 << 20)
+#define        AUX_SW_RX_RECV_INVALID_H                (1 << 22)
+#define        AUX_SW_RX_RECV_INVALID_V                (1 << 23)
+
+#define AUX_SW_DATA                                    0x6218
+#define AUX_SW_DATA_RW                                 (1 << 0)
+#define AUX_SW_DATA_MASK(x)                            (((x) & 0xff) << 8)
+#define AUX_SW_DATA_INDEX(x)                           (((x) & 0x1f) << 16)
+#define AUX_SW_AUTOINCREMENT_DISABLE                   (1 << 31)
+
 #define        LB_SYNC_RESET_SEL                               0x6b28
 #define                LB_SYNC_RESET_SEL_MASK                  (3 << 0)
 #define                LB_SYNC_RESET_SEL_SHIFT                 0
 
--- /dev/null
+/*
+ * Copyright 2015 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Dave Airlie
+ */
+#include <drm/drmP.h>
+#include <drm/radeon_drm.h>
+#include "radeon.h"
+#include "nid.h"
+
+#define AUX_RX_ERROR_FLAGS (AUX_SW_RX_OVERFLOW |            \
+                           AUX_SW_RX_HPD_DISCON |           \
+                           AUX_SW_RX_PARTIAL_BYTE |         \
+                           AUX_SW_NON_AUX_MODE |            \
+                           AUX_SW_RX_MIN_COUNT_VIOL |       \
+                           AUX_SW_RX_INVALID_STOP |         \
+                           AUX_SW_RX_SYNC_INVALID_L |       \
+                           AUX_SW_RX_SYNC_INVALID_H |       \
+                           AUX_SW_RX_INVALID_START |        \
+                           AUX_SW_RX_RECV_NO_DET |          \
+                           AUX_SW_RX_RECV_INVALID_H |       \
+                           AUX_SW_RX_RECV_INVALID_V)
+
+#define AUX_SW_REPLY_GET_BYTE_COUNT(x) (((x) >> 24) & 0x1f)
+
+#define BARE_ADDRESS_SIZE 3
+
+static const u32 aux_offset[] =
+{
+       0x6200 - 0x6200,
+       0x6250 - 0x6200,
+       0x62a0 - 0x6200,
+       0x6300 - 0x6200,
+       0x6350 - 0x6200,
+       0x63a0 - 0x6200,
+};
+
+ssize_t
+radeon_dp_aux_transfer_native(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
+{
+       struct radeon_i2c_chan *chan =
+               container_of(aux, struct radeon_i2c_chan, aux);
+       struct drm_device *dev = chan->dev;
+       struct radeon_device *rdev = dev->dev_private;
+       int ret = 0, i;
+       uint32_t tmp, ack = 0;
+       int instance = chan->rec.i2c_id & 0xf;
+       u8 byte;
+       u8 *buf = msg->buffer;
+       int retry_count = 0;
+       int bytes;
+       int msize;
+       bool is_write = false;
+
+       if (WARN_ON(msg->size > 16))
+               return -E2BIG;
+
+       switch (msg->request & ~DP_AUX_I2C_MOT) {
+       case DP_AUX_NATIVE_WRITE:
+       case DP_AUX_I2C_WRITE:
+               is_write = true;
+               break;
+       case DP_AUX_NATIVE_READ:
+       case DP_AUX_I2C_READ:
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       /* work out two sizes required */
+       msize = 0;
+       bytes = BARE_ADDRESS_SIZE;
+       if (msg->size) {
+               msize = msg->size - 1;
+               bytes++;
+               if (is_write)
+                       bytes += msg->size;
+       }
+
+       mutex_lock(&chan->mutex);
+
+       /* switch the pad to aux mode */
+       tmp = RREG32(chan->rec.mask_clk_reg);
+       tmp |= (1 << 16);
+       WREG32(chan->rec.mask_clk_reg, tmp);
+
+       /* setup AUX control register with correct HPD pin */
+       tmp = RREG32(AUX_CONTROL + aux_offset[instance]);
+
+       tmp &= AUX_HPD_SEL(0x7);
+       tmp |= AUX_HPD_SEL(chan->rec.hpd);
+       tmp |= AUX_EN | AUX_LS_READ_EN;
+
+       WREG32(AUX_CONTROL + aux_offset[instance], tmp);
+
+       /* atombios appears to write this twice lets copy it */
+       WREG32(AUX_SW_CONTROL + aux_offset[instance],
+              AUX_SW_WR_BYTES(bytes));
+       WREG32(AUX_SW_CONTROL + aux_offset[instance],
+              AUX_SW_WR_BYTES(bytes));
+
+       /* write the data header into the registers */
+       /* request, addres, msg size */
+       byte = (msg->request << 4);
+       WREG32(AUX_SW_DATA + aux_offset[instance],
+              AUX_SW_DATA_MASK(byte) | AUX_SW_AUTOINCREMENT_DISABLE);
+
+       byte = (msg->address >> 8) & 0xff;
+       WREG32(AUX_SW_DATA + aux_offset[instance],
+              AUX_SW_DATA_MASK(byte));
+
+       byte = msg->address & 0xff;
+       WREG32(AUX_SW_DATA + aux_offset[instance],
+              AUX_SW_DATA_MASK(byte));
+
+       byte = msize;
+       WREG32(AUX_SW_DATA + aux_offset[instance],
+              AUX_SW_DATA_MASK(byte));
+
+       /* if we are writing - write the msg buffer */
+       if (is_write) {
+               for (i = 0; i < msg->size; i++) {
+                       WREG32(AUX_SW_DATA + aux_offset[instance],
+                              AUX_SW_DATA_MASK(buf[i]));
+               }
+       }
+
+       /* clear the ACK */
+       WREG32(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
+
+       /* write the size and GO bits */
+       WREG32(AUX_SW_CONTROL + aux_offset[instance],
+              AUX_SW_WR_BYTES(bytes) | AUX_SW_GO);
+
+       /* poll the status registers - TODO irq support */
+       do {
+               tmp = RREG32(AUX_SW_STATUS + aux_offset[instance]);
+               if (tmp & AUX_SW_DONE) {
+                       break;
+               }
+               usleep_range(100, 200);
+       } while (retry_count++ < 1000);
+
+       if (retry_count >= 1000) {
+               DRM_ERROR("auxch hw never signalled completion, error %08x\n", tmp);
+               ret = -EIO;
+               goto done;
+       }
+
+       if (tmp & AUX_SW_RX_TIMEOUT) {
+               DRM_DEBUG_KMS("dp_aux_ch timed out\n");
+               ret = -ETIMEDOUT;
+               goto done;
+       }
+       if (tmp & AUX_RX_ERROR_FLAGS) {
+               DRM_DEBUG_KMS("dp_aux_ch flags not zero: %08x\n", tmp);
+               ret = -EIO;
+               goto done;
+       }
+
+       bytes = AUX_SW_REPLY_GET_BYTE_COUNT(tmp);
+       if (bytes) {
+               WREG32(AUX_SW_DATA + aux_offset[instance],
+                      AUX_SW_DATA_RW | AUX_SW_AUTOINCREMENT_DISABLE);
+
+               tmp = RREG32(AUX_SW_DATA + aux_offset[instance]);
+               ack = (tmp >> 8) & 0xff;
+
+               for (i = 0; i < bytes - 1; i++) {
+                       tmp = RREG32(AUX_SW_DATA + aux_offset[instance]);
+                       if (buf)
+                               buf[i] = (tmp >> 8) & 0xff;
+               }
+               if (buf)
+                       ret = bytes - 1;
+       }
+
+       WREG32(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
+
+       if (is_write)
+               ret = msg->size;
+done:
+       mutex_unlock(&chan->mutex);
+
+       if (ret >= 0)
+               msg->reply = ack >> 4;
+       return ret;
+}