i2c: add i2clookup host command

Add a new host command that will allow you to lookup a well known device
on the EC. This is useful for FAFT tests that want to talk directly
with i2c devices but don't know the physical address for each platform.

BRANCH=octopus
BUG=b:119065537
TEST=Used this with new faft test in CL:1601300

Change-Id: I82c2d5462fcb4edbc92ea60765971190fed7ae81
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1601060
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
(cherry picked from commit 45434aed20e695e08fcbb3f74c43e03f6fa19bf2)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1615653
Reviewed-by: Diana Z <dzigterman@chromium.org>

3 files changed, 110 insertions, 1 deletions

diff --git a/common/i2c_master.c b/common/i2c_master.c
index c2cc22f06c..73771f412e 100644
--- a/common/i2c_master.c
+++ b/common/i2c_master.c
@@ -761,6 +761,34 @@ static int i2c_command_passthru(struct host_cmd_handler_args *args)
 }
 DECLARE_HOST_COMMAND(EC_CMD_I2C_PASSTHRU, i2c_command_passthru, EC_VER_MASK(0));
 
+static int i2c_command_lookup(struct host_cmd_handler_args *args)
+{
+	const struct ec_params_i2c_lookup *params = args->params;
+	struct ec_response_i2c_lookup *resp = args->response;
+
+	switch (params->type) {
+	case I2C_LOOKUP_TYPE_CBI_EEPROM:
+#ifdef CONFIG_CROS_BOARD_INFO
+		resp->i2c_port = I2C_PORT_EEPROM;
+		/* Convert from 8-bit address to 7-bit address */
+		resp->i2c_addr = I2C_ADDR_EEPROM >> 1;
+#else
+		/* Lookup type is supported, but not present on system. */
+		return EC_RES_UNAVAILABLE;
+#endif /* CONFIG_CROS_BOARD_INFO */
+		break;
+	default:
+		/* The type was unrecognized */
+		return EC_RES_INVALID_PARAM;
+	}
+
+	args->response_size = sizeof(*resp);
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_I2C_LOOKUP, i2c_command_lookup, EC_VER_MASK(0));
+/* If the params union expands in the future, need to bump EC_VER_MASK */
+BUILD_ASSERT(sizeof(struct ec_params_i2c_lookup) == 4);
+
 void i2c_passthru_protect_port(uint32_t port)
 {
 	if (port < I2C_PORT_COUNT)
diff --git a/include/ec_commands.h b/include/ec_commands.h
index ac7e3ba022..e9100b8a67 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -5148,6 +5148,35 @@ struct ec_response_rollback_info {
 #define EC_CMD_AP_RESET 0x0125
 
 /*****************************************************************************/
+/* I2C lookup command
+ *
+ * Return values:
+ * EC_RES_UNAVAILABLE: Lookup type is supported but not present on system.
+ * EC_RES_INVALID_PARAM: The type was unrecognized.
+ */
+
+#define EC_CMD_I2C_LOOKUP 0x0126
+
+enum i2c_device_type {
+	I2C_LOOKUP_TYPE_CBI_EEPROM = 1,
+	I2C_LOOKUP_TYPE_COUNT,
+	I2C_LOOKUP_TYPE_MAX = 0xFFFF,
+};
+
+struct ec_params_i2c_lookup {
+	uint16_t type;		/* enum i2c_device_type */
+	/* Used for type specific parameters in future */
+	union {
+		uint16_t reseved;
+	};
+} __ec_align2;
+
+struct ec_response_i2c_lookup {
+	uint16_t i2c_port;	/* Physical port for device */
+	uint16_t i2c_addr;	/* 7-bit (or 10-bit) address */
+} __ec_align1;
+
+/*****************************************************************************/
 /* The command range 0x200-0x2FF is reserved for Rotor. */
 
 /*****************************************************************************/
diff --git a/util/ectool.c b/util/ectool.c
index 15d04424af..63c5bad3d9 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -6022,7 +6022,6 @@ int cmd_i2c_write(int argc, char *argv[])
 	return 0;
 }
 
-
 int cmd_i2c_xfer(int argc, char *argv[])
 {
 	unsigned int port, addr;
@@ -6099,6 +6098,58 @@ int cmd_i2c_xfer(int argc, char *argv[])
 	return 0;
 }
 
+static void cmd_i2c_lookup_help(const char *const cmd)
+{
+	fprintf(stderr,
+		"Usage: %s <type>\n"
+		"  <type> is one of:\n"
+		"    1: CBI_EEPROM\n",
+		cmd);
+}
+
+int cmd_i2c_lookup(int argc, char *argv[])
+{
+	struct ec_params_i2c_lookup p;
+	struct ec_response_i2c_lookup r;
+	char *e;
+	int rv;
+
+	if (argc != 2) {
+		cmd_i2c_lookup_help(argv[0]);
+		return -1;
+	}
+
+	p.type = strtol(argv[1], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad type.\n");
+		cmd_i2c_lookup_help(argv[0]);
+		return -1;
+	}
+
+	rv = ec_command(EC_CMD_I2C_LOOKUP, 0, &p, sizeof(p), &r, sizeof(r));
+
+	if (rv == -EC_RES_INVALID_PARAM - EECRESULT) {
+		fprintf(stderr, "Lookup type %d not supported.\n", p.type);
+		return rv;
+	}
+
+	if (rv == -EC_RES_UNAVAILABLE - EECRESULT) {
+		fprintf(stderr, "Device not found\n");
+		return rv;
+	}
+
+	if (rv < 0)
+		return rv;
+
+	/*
+	 * Do not change the format of this print. firmware_ECCbiEeprom FAFT
+	 * test depends on this, and will silently start skipping tests.
+	 */
+	printf("Port: %d; Address: 0x%02x (7-bit format)\n", r.i2c_port,
+	       r.i2c_addr);
+	return 0;
+}
+
 int cmd_lcd_backlight(int argc, char *argv[])
 {
 	struct ec_params_switch_enable_backlight p;
@@ -8464,6 +8515,7 @@ const struct command commands[] = {
 	{"hello", cmd_hello},
 	{"hibdelay", cmd_hibdelay},
 	{"hostsleepstate", cmd_hostsleepstate},
+	{"i2clookup", cmd_i2c_lookup},
 	{"i2cprotect", cmd_i2c_protect},
 	{"i2cread", cmd_i2c_read},
 	{"i2cwrite", cmd_i2c_write},