ISH: IPC: implement generic IPC layer

Introduce new IPC API supporting MNG and HECI protocols.
Currently it supports communication with host(x64)

BUG=b:79676054
BRANCH=none
TEST=Tested on Atlas board.

Change-Id: Iea6d1f96c89228b425861d045618d58f9d146f08
Reviewed-on: https://chromium-review.googlesource.com/1279363
Commit-Ready: Hyungwoo Yang <hyungwoo.yang@intel.com>
Tested-by: Hyungwoo Yang <hyungwoo.yang@intel.com>
Reviewed-by: Hyungwoo Yang <hyungwoo.yang@intel.com>
Reviewed-by: Jett Rink <jettrink@chromium.org>

1 files changed, 83 insertions, 0 deletions

diff --git a/chip/ish/ipc_heci.h b/chip/ish/ipc_heci.h
new file mode 100644
index 0000000000..e7238df83d
--- /dev/null
+++ b/chip/ish/ipc_heci.h
@@ -0,0 +1,83 @@
+/* Copyright 2018 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* IPC module for ISH */
+#ifndef __IPC_HECI_H
+#define __IPC_HECI_H
+
+enum IPC_ERR {
+	IPC_ERR_IPC_IS_NOT_READY	= EC_ERROR_INTERNAL_FIRST + 0,
+	IPC_ERR_TOO_SMALL_BUFFER	= EC_ERROR_INTERNAL_FIRST + 1,
+	IPC_ERR_TX_QUEUE_FULL		= EC_ERROR_INTERNAL_FIRST + 2,
+	IPC_ERR_INVALID_TASK		= EC_ERROR_INTERNAL_FIRST + 3,
+	IPC_ERR_MSG_NOT_AVAILABLE	= EC_ERROR_INTERNAL_FIRST + 4,
+	IPC_ERR_INVALID_MSG		= EC_ERROR_INTERNAL_FIRST + 5,
+};
+
+enum ipc_peer_id {
+	IPC_PEER_ID_HOST	= 0, /* x64 host */
+#if 0 /* other peers are not implemented yet */
+	IPC_PEER_ID_PMC		= 1, /* Power Management Controller */
+	IPC_PEER_ID_CSME	= 2, /* Converged Security Management Engine */
+	IPC_PEER_ID_CAVS    = 3, /* Audio, Voice, and Speech engine */
+	IPC_PEER_ID_ISP 	= 4, /* Image Signal Processor */
+#endif
+	IPC_PEERS_COUNT,
+};
+/*
+ * Currently ipc handle encoding only allows maximum 16 peers which is
+ * enough for ISH3, ISH4, and ISH5. They have 5 peers.
+ */
+BUILD_ASSERT(IPC_PEERS_COUNT <= 0x0F);
+
+enum ipc_protocol {
+	IPC_PROTOCOL_BOOT = 0,	/* Not supported */
+	IPC_PROTOCOL_HECI,	/* Host Embedded Controller Interface */
+	IPC_PROTOCOL_MCTP,	/* not supported */
+	IPC_PROTOCOL_MNG,	/* Management protocol */
+	IPC_PROTOCOL_ECP,	/* EC Protocol. not supported */
+	IPC_PROTOCOL_COUNT
+};
+/*
+ * IPC handle enconding only supports 16 protocols which is the
+ * maximum protocols supported by IPC doorbell encoding.
+ */
+BUILD_ASSERT(IPC_PROTOCOL_COUNT <= 0x0F);
+
+typedef void *				ipc_handle_t;
+
+#define IPC_MAX_PAYLOAD_SIZE		128
+#define IPC_INVALID_HANDLE		NULL
+
+/*
+ * Open ipc channel
+ *
+ * @param peer_id	select peer to communicate.
+ * @param protocol	select protocol
+ * @param event		set event flag
+ *
+ * @return		ipc handle or IPC_INVALID_HANDLE if there's error
+ */
+ipc_handle_t ipc_open(const enum ipc_peer_id peer_id,
+		      const enum ipc_protocol protocol,
+		      const uint32_t event);
+void ipc_close(const ipc_handle_t handle);
+
+/*
+ * Read message from ipc channel.
+ * The function should be call by the same task called ipc_open().
+ * The function waits until message is available.
+ * @param timeout_us	if == -1, wait until message is available.
+ *			if == 0, return immediately.
+ *			if > 0, wait for the specified microsecond duration time
+ */
+int ipc_read(const ipc_handle_t handle, void *buf, const size_t buf_size,
+             int timeout_us);
+
+/* Write message to ipc channel. */
+int ipc_write(const ipc_handle_t handle, const void *buf,
+	      const size_t buf_size);
+
+#endif /* __IPC_HECI_H */