/*
  * H2M_MAILBOX_CSR: Host-to-MCU Mailbox.
+ * CMD_TOKEN: Command id, 0xff disable status reporting.
  */
 #define H2M_MAILBOX_CSR                        0x7010
 #define H2M_MAILBOX_CSR_ARG0           FIELD32(0x000000ff)
 
 /*
  * H2M_MAILBOX_CID:
+ * Free slots contain 0xff. MCU will store command's token to lowest free slot.
+ * If all slots are occupied status will be dropped.
  */
 #define H2M_MAILBOX_CID                        0x7014
 #define H2M_MAILBOX_CID_CMD0           FIELD32(0x000000ff)
 
 /*
  * H2M_MAILBOX_STATUS:
+ * Command status will be saved to same slot as command id.
  */
 #define H2M_MAILBOX_STATUS             0x701c
 
 
 /*
  * MCU mailbox commands.
+ * MCU_SLEEP - go to power-save mode.
+ *             arg1: 1: save as much power as possible, 0: save less power.
+ *             status: 1: success, 2: already asleep,
+ *                     3: maybe MAC is busy so can't finish this task.
+ * MCU_RADIO_OFF
+ *             arg0: 0: do power-saving, NOT turn off radio.
  */
 #define MCU_SLEEP                      0x30
 #define MCU_WAKEUP                     0x31
 /*
  * MCU mailbox tokens
  */
-#define TOKEN_WAKUP                    3
+#define TOKEN_SLEEP                    1
+#define TOKEN_RADIO_OFF                        2
+#define TOKEN_WAKEUP                   3
+
 
 /*
  * DMA descriptor defines.
 
                               enum dev_state state)
 {
        if (state == STATE_AWAKE) {
-               rt2800_mcu_request(rt2x00dev, MCU_WAKEUP, TOKEN_WAKUP, 0, 0x02);
-               rt2800pci_mcu_status(rt2x00dev, TOKEN_WAKUP);
+               rt2800_mcu_request(rt2x00dev, MCU_WAKEUP, TOKEN_WAKEUP,
+                                  0, 0x02);
+               rt2800pci_mcu_status(rt2x00dev, TOKEN_WAKEUP);
        } else if (state == STATE_SLEEP) {
                rt2x00pci_register_write(rt2x00dev, H2M_MAILBOX_STATUS,
                                         0xffffffff);
                rt2x00pci_register_write(rt2x00dev, H2M_MAILBOX_CID,
                                         0xffffffff);
-               rt2800_mcu_request(rt2x00dev, MCU_SLEEP, 0x01, 0xff, 0x01);
+               rt2800_mcu_request(rt2x00dev, MCU_SLEEP, TOKEN_SLEEP,
+                                  0xff, 0x01);
        }
 
        return 0;