ish: add cros_ec command interface over heci

Implement the cros_ec host command V3 interface using the
HECI (and ISHTP client) transport layer with the host. To work, the
kernel needs a cros_ec over heci implementation (which is also under
development)

BRANCH=none
BUG=b:123075957,b:120295222
TEST=using this CL and draft kernel client implementation, AP can
     communicate with ISH via cros_ec interface including transferring
     sensor data from ISH to AP

Change-Id: I1d9801ddf31ef6bdbfe44ccfca435884e2cf4da6
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/1460084
Commit-Queue: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Edward Hill <ecgh@chromium.org>
Reviewed-by: Rushikesh S Kadam <rushikesh.s.kadam@intel.com>

3 files changed, 115 insertions, 0 deletions

diff --git a/chip/ish/build.mk b/chip/ish/build.mk
index c938df70fd..e2fc4872de 100644
--- a/chip/ish/build.mk
+++ b/chip/ish/build.mk
@@ -24,6 +24,7 @@ chip-$(CONFIG_ISH_IPC)+=ipc_heci.o
 chip-$(CONFIG_HECI)+=heci.o system_state_subsys.o
 chip-$(CONFIG_HID_SUBSYS)+=hid_subsys.o
 chip-$(CONFIG_WATCHDOG)+=watchdog.o
+chip-$(CONFIG_HOSTCMD_HECI)+=host_command_heci.o
 
 # location of the scripts and keys used to pack the SPI flash image
 SCRIPTDIR:=./chip/${CHIP}/util
diff --git a/chip/ish/host_command_heci.c b/chip/ish/host_command_heci.c
new file mode 100644
index 0000000000..a110bca605
--- /dev/null
+++ b/chip/ish/host_command_heci.c
@@ -0,0 +1,111 @@
+/* Copyright 2019 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.
+ */
+
+#include "common.h"
+#include "console.h"
+#include "heci_client.h"
+#include "host_command.h"
+#include "ipc_heci.h"
+#include "util.h"
+
+#define CPUTS(outstr) cputs(CC_LPC, outstr)
+#define CPRINTS(format, args...) cprints(CC_LPC, format, ## args)
+#define CPRINTF(format, args...) cprintf(CC_LPC, format, ## args)
+
+#define HECI_CLIENT_CROS_EC_ISH_GUID { 0x7b7154d0, 0x56f4, 0x4bdc,\
+			 { 0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0 } }
+
+/* Handle for all heci cros_ec interactions */
+static heci_handle_t heci_cros_ec_handle = HECI_INVALID_HANDLE;
+
+/*
+ * If we hit response buffer size issues, we can increase this. This is the
+ * current size of a single HECI packet.
+ *
+ * Aligning with other assumptions in host command stack, only a single host
+ * command can be processed at a given time.
+ */
+static uint8_t response_buffer[IPC_MAX_PAYLOAD_SIZE] __aligned(4);
+static struct host_packet heci_packet;
+
+#define HECI_CROS_EC_RESPONSE_MAX sizeof(response_buffer)
+
+static void heci_send_response_packet(struct host_packet *pkt)
+{
+	heci_send_msg(heci_cros_ec_handle, pkt->response, pkt->response_size);
+}
+
+static void cros_ec_ishtp_subsys_new_msg_received(const heci_handle_t handle,
+					uint8_t *msg, const size_t msg_size)
+{
+	memset(&heci_packet, 0, sizeof(heci_packet));
+
+	heci_packet.send_response = heci_send_response_packet;
+
+	heci_packet.request = msg;
+	heci_packet.request_max = HECI_MAX_MSG_SIZE;
+	heci_packet.request_size = msg_size;
+
+	heci_packet.response = &response_buffer;
+	heci_packet.response_max = HECI_CROS_EC_RESPONSE_MAX;
+	heci_packet.response_size = 0;
+
+	heci_packet.driver_result = EC_RES_SUCCESS;
+	host_packet_receive(&heci_packet);
+}
+
+/*
+ * IPC transfer max is actual 4K, but we don't need kernel buffers that big
+ *
+ * Basing size off of existing cros_ec implementations ranging from 128 to 512
+ */
+#define HECI_CROS_EC_LIMIT_PACKET_SIZE 256
+
+/**
+ * Get protocol information
+ */
+static int heci_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 = HECI_CROS_EC_LIMIT_PACKET_SIZE;
+	r->max_response_packet_size = HECI_CROS_EC_RESPONSE_MAX;
+
+	args->response_size = sizeof(*r);
+
+	return EC_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_GET_PROTOCOL_INFO, heci_get_protocol_info,
+EC_VER_MASK(0));
+
+static int cros_ec_ishtp_subsys_initialize(const heci_handle_t heci_handle)
+{
+	heci_cros_ec_handle = heci_handle;
+	return EC_SUCCESS;
+}
+
+static int cros_ec_ishtp_no_op(const heci_handle_t heci_handle)
+{
+	return EC_SUCCESS;
+}
+
+static const struct heci_client_callbacks cros_ec_ishtp_subsys_heci_cbs = {
+	.initialize = cros_ec_ishtp_subsys_initialize,
+	.new_msg_received = cros_ec_ishtp_subsys_new_msg_received,
+	.suspend = cros_ec_ishtp_no_op,
+	.resume = cros_ec_ishtp_no_op,
+};
+
+static const struct heci_client cros_ec_ishtp_heci_client = {
+	.protocol_id = HECI_CLIENT_CROS_EC_ISH_GUID,
+	.max_msg_size = HECI_MAX_MSG_SIZE,
+	.protocol_ver = 1,
+	.max_n_of_connections = 1,
+	.cbs = &cros_ec_ishtp_subsys_heci_cbs,
+};
+
+HECI_CLIENT_ENTRY(cros_ec_ishtp_heci_client);
diff --git a/include/config.h b/include/config.h
index 8baea11ff9..ca698e5b6e 100644
--- a/include/config.h
+++ b/include/config.h
@@ -2406,6 +2406,9 @@
  */
 #undef CONFIG_ISH_IPC
 
+/* Support host command interface over HECI */
+#undef CONFIG_HOSTCMD_HECI
+
 /*
  * EC supports x86 host communication with AP. This can either be through LPC
  * or eSPI. The CONFIG_HOSTCMD_X86 will get automatically defined if either