samus: Add host command to store USB PD device id & rw_hash entry.

PD accessories that are RW update-able will broadcast their rw_hash
SHA1 digest upon connection and remain in RO briefly for a response.

In order to speed-up the response and decouple common case of
accessory is up-to-date, the PD MCU will keep a small 4 entry table of
PD accessory device ids and their corresponding RW hashes for quick
lookup.

The AP will be the source of new updates and their corresponding
device id's and RW hashes and therefore needs a method to update the
PD MCU table.

This CL creates the table, host command & ectool command to facilitate
future driver / daemon to update the RW hash entries.

BRANCH=none
BUG=chrome-os-partner:31361
TEST=manual,

  # from AP
  for i in `seq 1 8` ; do
    ectool --dev=1 --interface=lpc rwhashpd $i $i $i $i $i $i
  done

  # from samus_pd console
  pd rwhash
  Device:5 Hash: 0x00000005 0x00000005 0x00000005 0x00000005 0x00000005
  Device:6 Hash: 0x00000006 0x00000006 0x00000006 0x00000006 0x00000006
  Device:7 Hash: 0x00000007 0x00000007 0x00000007 0x00000007 0x00000007
  Device:8 Hash: 0x00000008 0x00000008 0x00000008 0x00000008 0x00000008

Change-Id: Ibe87b3594793cd5215eba42160489b26974aadbc
Signed-off-by: Todd Broch <tbroch@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/214366
Reviewed-by: Alec Berg <alecaberg@chromium.org>

3 files changed, 102 insertions, 1 deletions

diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index c4882892ac..ed358dbc56 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -266,6 +266,14 @@ static uint8_t pd_comm_enabled = CONFIG_USB_PD_COMM_ENABLED;
 
 struct mutex pd_crc_lock;
 
+/*
+ * 4 entry rw_hash table of type-C devices that AP has firmware updates for.
+ */
+#ifdef CONFIG_COMMON_RUNTIME
+#define RW_HASH_ENTRIES 4
+static struct ec_params_usb_pd_rw_hash_entry rw_hash_table[RW_HASH_ENTRIES];
+#endif
+
 static inline void set_state_timeout(int port,
 				     uint64_t timeout,
 				     enum pd_states timeout_state)
@@ -1633,10 +1641,24 @@ static int command_pd(int argc, char **argv)
 	int port;
 	char *e;
 
-	if (argc < 3)
+	if (argc < 2)
 		return EC_ERROR_PARAM_COUNT;
 
+	if (!strncasecmp(argv[1], "rwhashtable", 3)) {
+		int i, j;
+		struct ec_params_usb_pd_rw_hash_entry *p;
+		for (i = 0; i < RW_HASH_ENTRIES; i++) {
+			p = &rw_hash_table[i];
+			ccprintf("Device:%d Hash:", p->dev_id);
+			for (j = 0; j < SHA1_DIGEST_SIZE/4; j++)
+				ccprintf(" 0x%08x", p->dev_rw_hash.w[j]);
+			ccprintf("\n");
+		}
+		return EC_SUCCESS;
+	}
 	port = strtoi(argv[1], &e, 10);
+	if (argc < 3)
+		return EC_ERROR_PARAM_COUNT;
 	if (*e || port >= PD_PORT_COUNT)
 		return EC_ERROR_PARAM2;
 
@@ -1966,4 +1988,38 @@ DECLARE_HOST_COMMAND(EC_CMD_USB_PD_FW_UPDATE,
 		     hc_remote_flash,
 		     EC_VER_MASK(0));
 
+static int hc_remote_rw_hash_entry(struct host_cmd_handler_args *args)
+{
+	int i, idx = 0, found = 0;
+	const struct ec_params_usb_pd_rw_hash_entry *p = args->params;
+	static int rw_hash_next_idx;
+
+	if (!p->dev_id) {
+		ccprintf("PD RW_HASH - 0 is not a valid device id");
+		return EC_RES_INVALID_PARAM;
+	}
+
+	for (i = 0; i < RW_HASH_ENTRIES; i++) {
+		if (p->dev_id == rw_hash_table[i].dev_id) {
+			idx = i;
+			found = 1;
+			break;
+		}
+	}
+	if (!found) {
+		idx = rw_hash_next_idx;
+		rw_hash_next_idx = rw_hash_next_idx + 1;
+		if (rw_hash_next_idx == RW_HASH_ENTRIES)
+			rw_hash_next_idx = 0;
+	}
+	memcpy(&rw_hash_table[idx], p, sizeof(*p));
+	ccprintf("PD RW_HASH - stored dev_id:%d at index:%d\n",
+		 rw_hash_table[idx].dev_id, idx);
+
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_USB_PD_RW_HASH_ENTRY,
+		     hc_remote_rw_hash_entry,
+		     EC_VER_MASK(0));
+
 #endif /* CONFIG_COMMON_RUNTIME */
diff --git a/include/ec_commands.h b/include/ec_commands.h
index 64b70909b4..27b3107c16 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -2,6 +2,7 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+#include "sha1.h"
 
 /* Host communication command constants for Chrome EC */
 
@@ -2626,7 +2627,16 @@ struct ec_params_usb_pd_fw_update {
 	/* Followed by data to write */
 } __packed;
 
+/* Write USB-PD Accessory RW_HASH table entry */
+#define EC_CMD_USB_PD_RW_HASH_ENTRY 0x111
 
+struct ec_params_usb_pd_rw_hash_entry {
+	uint8_t dev_id;
+	union {
+		uint8_t b[SHA1_DIGEST_SIZE];
+		uint32_t w[DIV_ROUND_UP(SHA1_DIGEST_SIZE, sizeof(uint32_t))];
+	} dev_rw_hash;
+} __packed;
 /*****************************************************************************/
 /*
  * Passthru commands
diff --git a/util/ectool.c b/util/ectool.c
index 8f722f974d..0d380c0e78 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -160,6 +160,8 @@ const char help_str[] =
 	"      Print real-time clock\n"
 	"  rtcset <time>\n"
 	"      Set real-time clock\n"
+	"  rwhashpd <dev_id> <SHA1[0] ... <SHA1[4]>\n"
+	"      Set entry in PD MCU's device rw_hash table.\n"
 	"  sertest\n"
 	"      Serial output test for COM2\n"
 	"  switches\n"
@@ -778,6 +780,38 @@ int cmd_flash_protect(int argc, char *argv[])
 	return 0;
 }
 
+int cmd_rw_hash_pd(int argc, char *argv[])
+{
+	struct ec_params_usb_pd_rw_hash_entry *p =
+		(struct ec_params_usb_pd_rw_hash_entry *)ec_outbuf;
+	int i, rv;
+	char *e;
+
+	if (argc < 7) {
+		fprintf(stderr, "Usage: %s <dev_id> <SHA1[0]> ... <SHA1[4]>\n",
+			argv[0]);
+		return -1;
+	}
+
+	p->dev_id = strtol(argv[1], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad device ID\n");
+		return -1;
+	}
+
+	for (i = 2; i < 7; i++) {
+		p->dev_rw_hash.w[i - 2] = strtol(argv[i], &e, 0);
+		if (e && *e) {
+			fprintf(stderr, "Bad SHA1 digest\n");
+			return -1;
+		}
+	}
+	rv = ec_command(EC_CMD_USB_PD_RW_HASH_ENTRY, 0, p, sizeof(*p), NULL, 0);
+
+	return rv;
+}
+
+
 /* PD image size is 16k minus 32 bits for the RW hash */
 #define PD_RW_IMAGE_SIZE (16 * 1024 - 32)
 static struct sha1_ctx ctx;
@@ -4729,6 +4763,7 @@ const struct command commands[] = {
 	{"reboot_ec", cmd_reboot_ec},
 	{"rtcget", cmd_rtc_get},
 	{"rtcset", cmd_rtc_set},
+	{"rwhashpd", cmd_rw_hash_pd},
 	{"sertest", cmd_serial_test},
 	{"port80flood", cmd_port_80_flood},
 	{"switches", cmd_switches},