IOC mediator: Send open channel command to activate CBC signal channel by default

To send open channel command after opening CBC signal channel successfully.
For the latest IOC firmware, the IOC mediator needs to send open channel command
to activate CBC signal channel. Otherwise, there will be no any signal data will
be received.

The open channel command is forward compatible that it would not impact for
older IOC firmware.

Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Yu Wang <yu1.wang@intel.com>
Reviewed-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

Author: yliu80

devicemodel/hw/platform/ioc.c

@@ -124,6 +124,16 @@ typedef void* (*ioc_work)(void *arg);
  */
 static char virtual_uart_path[32];
 
+/*
+ * To activate CBC signal channel(/dev/cbc-signals).
+ * Need to send open channel command to CBC signal char device before receive
+ * signal data.
+ * NOTE: Only send open channel command, no need to send close channel since
+ * close channel command would deactivate the signal channel for all UOS, so
+ * there will be a SOS service to deactivate signal channel in the future.
+ */
+static uint8_t cbc_open_channel_command[] = {0xFD, 0x00, 0x00, 0x00};
+
 /* IOC boot reason(for S5)
  * comes from DM command line parameters.
  */
@@ -1365,6 +1375,16 @@ ioc_init(struct vmctx *ctx)
 	if (ioc_ch_init(ioc) != 0)
 		goto chl_err;
 
+	/*
+	 * Make sure the CBC signal channel is activated after channel
+	 * initialization is successful.
+	 * TODO: Check firmware version before sending open channel command
+	 * since the old IOC firmware needs not use open channel command to
+	 * activate signal channel that is activated by default.
+	 */
+	if (ioc_ch_xmit(IOC_NATIVE_SIGNAL, cbc_open_channel_command,
+				sizeof(cbc_open_channel_command)) <= 0)
+		DPRINTF("%s", "ioc sends CBC open channel command failed\r\n");
 
 	/* Initlialize CBC rx/tx signal and group whitelists */
 	wlist_init_signal(cbc_rx_signal_table, ARRAY_SIZE(cbc_rx_signal_table),