mt_scp/ipi: Support host command.

mt_scp is the first chip which uses IPI to do host command communication.
This CL implements the host command over IPI.

TEST=Run ec.RW.bin on kukui by "echo start >
/sys/class/remoteproc/remoteproc0/state" and see that there are HC logs
from SCP uart
[0.000385 hostcmd init 0x0000000000002000]
[0.049958 HC 0x0b]
[0.050061 HC 0x400b]
[0.050108 HC 0x400b err 1]
[0.050204 HC 0x08]
[0.050240 HC 0x08 err 3]
[0.050370 HC 0x8d]
[0.050406 HC 0x8d err 1]
[0.050821 HC 0x0d]
BUG=b:117917141, b:120953723
BRANCH=None

Change-Id: I2c2b701d92504a74cc2ee90ab05912e99378acde
Signed-off-by: Yilun Lin <yllin@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1379410
Commit-Ready: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Yilun Lin <yllin@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

1 files changed, 72 insertions, 0 deletions

diff --git a/chip/mt_scp/ipi.c b/chip/mt_scp/ipi.c
index 91e46740c9..a8bfce0a11 100644
--- a/chip/mt_scp/ipi.c
+++ b/chip/mt_scp/ipi.c
@@ -41,6 +41,9 @@ static struct ipc_shared_obj *const scp_send_obj =
 static struct ipc_shared_obj *const scp_recv_obj =
 	(struct ipc_shared_obj *)(CONFIG_IPC_SHARED_OBJ_ADDR +
 				  sizeof(struct ipc_shared_obj));
+#ifdef HAS_TASK_HOSTCMD
+static struct host_packet ipi_packet;
+#endif
 
 /* Check if SCP to AP IPI is in use. */
 static inline int is_ipi_busy(void)
@@ -141,6 +144,75 @@ void ipi_inform_ap(void)
 		ccprintf("Failed to send initialization IPC messages.\n");
 }
 
+#ifdef HAS_TASK_HOSTCMD
+static void ipi_send_response_packet(struct host_packet *pkt)
+{
+	int ret;
+
+	ret = ipi_send(IPI_HOST_COMMAND, pkt->response, pkt->response_size, 0);
+	if (ret)
+		CPRINTS("#ERR IPI HOSTCMD %d", ret);
+}
+
+static void ipi_hostcmd_handler(int32_t id, void *buf, uint32_t len)
+{
+	uint8_t *in_msg = buf;
+	struct ec_host_request *r = (struct ec_host_request *)in_msg;
+	int i;
+
+	if (in_msg[0] != EC_HOST_REQUEST_VERSION) {
+		CPRINTS("ERROR: Protocol V2 is not supported!");
+		CPRINTF("in_msg=[");
+		for (i = 0; i < len; i++)
+			CPRINTF("%02x ", in_msg[i]);
+		CPRINTF("]\n");
+		return;
+	}
+
+	/* Protocol version 3 */
+
+	ipi_packet.send_response = ipi_send_response_packet;
+
+	/*
+	 * Just assign the buffer to request, host_packet_receive
+	 * handles the buffer copy.
+	 */
+	ipi_packet.request = (void *)r;
+	ipi_packet.request_temp = NULL;
+	ipi_packet.request_max = IPI_MAX_REQUEST_SIZE;
+	ipi_packet.request_size = host_request_expected_size(r);
+
+	ipi_packet.response = scp_send_obj->buffer;
+	/* Reserve space for the preamble and trailing byte */
+	ipi_packet.response_max = IPI_MAX_RESPONSE_SIZE;
+	ipi_packet.response_size = 0;
+
+	ipi_packet.driver_result = EC_RES_SUCCESS;
+
+	host_packet_receive(&ipi_packet);
+}
+DECLARE_IPI(IPI_HOST_COMMAND, ipi_hostcmd_handler, 0);
+
+/*
+ * Get protocol information
+ */
+static int ipi_get_protocol_info(struct host_cmd_handler_args *args)
+{
+	struct ec_response_get_protocol_info *r = args->response;
+
+	memset(r, 0, sizeof(*r));
+	r->protocol_versions |= (1 << 3);
+	r->max_request_packet_size = IPI_MAX_REQUEST_SIZE;
+	r->max_response_packet_size = IPI_MAX_RESPONSE_SIZE;
+
+	args->response_size = sizeof(*r);
+
+	return EC_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_GET_PROTOCOL_INFO, ipi_get_protocol_info,
+		     EC_VER_MASK(0));
+#endif
+
 static void ipi_enable_ipc0_deferred(void)
 {
 	/* Clear IPC0 IRQs. */