bus: mhi: core: Allow sending the STOP channel command

Add support to allow sending the STOP channel command. If a
client driver would like to STOP a channel and have the device
retain the channel context instead of issuing a RESET to it and
clearing the context, this would provide support for it after
the ability to send this command is exposed to clients.
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1617311778-1254-2-git-send-email-bbhatt@codeaurora.orgSigned-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

drivers/bus/mhi/core/main.c

@@ -1216,6 +1216,11 @@ int mhi_send_cmd(struct mhi_controller *mhi_cntrl,
 		cmd_tre->dword[0] = MHI_TRE_CMD_RESET_DWORD0;
 		cmd_tre->dword[1] = MHI_TRE_CMD_RESET_DWORD1(chan);
 		break;
+	case MHI_CMD_STOP_CHAN:
+		cmd_tre->ptr = MHI_TRE_CMD_STOP_PTR;
+		cmd_tre->dword[0] = MHI_TRE_CMD_STOP_DWORD0;
+		cmd_tre->dword[1] = MHI_TRE_CMD_STOP_DWORD1(chan);
+		break;
 	case MHI_CMD_START_CHAN:
 		cmd_tre->ptr = MHI_TRE_CMD_START_PTR;
 		cmd_tre->dword[0] = MHI_TRE_CMD_START_DWORD0;