samus: add options for device passthru and interface

This allows sending host commands to the PD chip through the EC.

The --interface option allows forcing a particular host interface.
This is necessary at present because the crosec device driver doesn't
support host protocol v3 so only has 8-bit command numbers.

BUG=chrome-os-partner:30079
BRANCH=none
TEST=from EC console,
   ectool version -> prints EC version
   ectool --interface=lpc --dev=0 version -> prints EC version
   ectool --interface=lpc --dev=1 version -> prints PD version
   ectool --interface=lpc --dev=2 version -> prints error
   ectool --interface=i2c version -> can't find EC
   ectool --interface=dev version -> prints EC version

Change-Id: I9dd10578dac77e3e104d19e2f37759814eec6ca2
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/207948

util/burn_my_ec.c

@@ -130,7 +130,7 @@ int main(int argc, char *argv[])
 {
 	extern uint8_t data[] asm("_payload_start");
 
-	if (comm_init() < 0)
+	if (comm_init(COMM_ALL) < 0)
 		return -3;
 
 	flash_partition(EC_IMAGE_RW, data + CONFIG_FW_RW_OFF,

util/comm-dev.c

@@ -102,7 +102,7 @@ int comm_init_dev(void)
 		return 3;
 	}
 
-	ec_command = ec_command_dev;
+	ec_command_proto = ec_command_dev;
 	if (ec_readmem_dev(EC_MEMMAP_ID, 2, version) == 2 &&
 	    version[0] == 'E' && version[1] == 'C')
 		ec_readmem = ec_readmem_dev;

util/comm-host.c

@@ -11,15 +11,16 @@
 #include "comm-host.h"
 #include "ec_commands.h"
 
-int (*ec_command)(int command, int version,
-		  const void *outdata, int outsize,
-		  void *indata, int insize);
+int (*ec_command_proto)(int command, int version,
+			const void *outdata, int outsize,
+			void *indata, int insize);
 
 int (*ec_readmem)(int offset, int bytes, void *dest);
 
 int ec_max_outsize, ec_max_insize;
 void *ec_outbuf;
 void *ec_inbuf;
+static int command_offset;
 
 int comm_init_dev(void) __attribute__((weak));
 int comm_init_lpc(void) __attribute__((weak));
@@ -58,21 +59,36 @@ static int fake_readmem(int offset, int bytes, void *dest)
 	return EC_MEMMAP_TEXT_MAX - 1;
 }
 
-int comm_init(void)
+void set_command_offset(int offset)
+{
+	command_offset = offset;
+}
+
+int ec_command(int command, int version,
+	       const void *outdata, int outsize,
+	       void *indata, int insize)
+{
+	/* Offset command code to support sub-devices */
+	return ec_command_proto(command_offset + command, version,
+				outdata, outsize,
+				indata, insize);
+}
+
+int comm_init(int interfaces)
 {
 	/* Default memmap access */
 	ec_readmem = fake_readmem;
 
 	/* Prefer new /dev method */
-	if (comm_init_dev && !comm_init_dev())
+	if ((interfaces & COMM_DEV) && comm_init_dev && !comm_init_dev())
 		goto init_ok;
 
 	/* Fallback to direct LPC on x86 */
-	if (comm_init_lpc && !comm_init_lpc())
+	if ((interfaces & COMM_LPC) && comm_init_lpc && !comm_init_lpc())
 		goto init_ok;
 
 	/* Fallback to direct i2c on ARM */
-	if (comm_init_i2c && !comm_init_i2c())
+	if ((interfaces & COMM_I2C) && comm_init_i2c && !comm_init_i2c())
 		goto init_ok;
 
 	/* Give up */

util/comm-host.h

@@ -25,19 +25,45 @@ extern int ec_max_outsize, ec_max_insize;
 extern void *ec_outbuf;
 extern void *ec_inbuf;
 
+/* Interfaces to allow for comm_init() */
+enum comm_interface {
+	COMM_DEV = (1 << 0),
+	COMM_LPC = (1 << 1),
+	COMM_I2C = (1 << 2),
+	COMM_ALL = -1
+};
+
 /**
  * Perform initializations needed for subsequent requests
  *
- * returns 0 in case of success or error code. */
-int comm_init(void);
+ * @param interfaces	Interfaces to try; use COMM_ALL to try all of them.
+ * @return 0 in case of success, or error code.
+ */
+int comm_init(int interfaces);
 
 /**
  * Send a command to the EC.  Returns the length of output data returned (0 if
  * none), or negative on error.
  */
-extern int (*ec_command)(int command, int version,
-			 const void *outdata, int outsize, /* to the EC */
-			 void *indata, int insize);	   /* from the EC */
+int ec_command(int command, int version,
+	       const void *outdata, int outsize,   /* to the EC */
+	       void *indata, int insize);	   /* from the EC */
+
+/**
+ * Set the offset to be applied to the command number when ec_command() calls
+ * ec_command_proto().
+ */
+void set_command_offset(int offset);
+
+/**
+ * Send a command to the EC.  Returns the length of output data returned (0 if
+ * none), or negative on error.  This is the low-level interface implemented
+ * by the protocol-specific driver.  DO NOT call this version directly from
+ * anywhere but ec_command(), or the --device option will not work.
+ */
+extern int (*ec_command_proto)(int command, int version,
+			       const void *outdata, int outsize, /* to EC */
+			       void *indata, int insize);        /* from EC */
 
 /**
  * Return the content of the EC information area mapped as "memory".

util/comm-i2c.c

@@ -206,7 +206,7 @@ int comm_init_i2c(void)
 
 	free(file_path);
 
-	ec_command = ec_command_i2c;
+	ec_command_proto = ec_command_i2c;
 	ec_max_outsize = ec_max_insize = EC_PROTO2_MAX_PARAM_SIZE;
 
 	return 0;

util/comm-lpc.c

@@ -289,7 +289,7 @@ int comm_init_lpc(void)
 
 	if (i & EC_HOST_CMD_FLAG_VERSION_3) {
 		/* Protocol version 3 */
-		ec_command = ec_command_lpc_3;
+		ec_command_proto = ec_command_lpc_3;
 		ec_max_outsize = EC_LPC_HOST_PACKET_SIZE -
 			sizeof(struct ec_host_request);
 		ec_max_insize = EC_LPC_HOST_PACKET_SIZE -
@@ -297,7 +297,7 @@ int comm_init_lpc(void)
 
 	} else if (i & EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED) {
 		/* Protocol version 2 */
-		ec_command = ec_command_lpc;
+		ec_command_proto = ec_command_lpc;
 		ec_max_outsize = ec_max_insize = EC_PROTO2_MAX_PARAM_SIZE;
 
 	} else {

util/comm-mec1322.c

@@ -342,7 +342,7 @@ int comm_init_lpc(void)
 
 	if (i & EC_HOST_CMD_FLAG_VERSION_3) {
 		/* Protocol version 3 */
-		ec_command = ec_command_lpc_3;
+		ec_command_proto = ec_command_lpc_3;
 		ec_max_outsize = EC_LPC_HOST_PACKET_SIZE -
 			sizeof(struct ec_host_request);
 		ec_max_insize = EC_LPC_HOST_PACKET_SIZE -
@@ -350,7 +350,7 @@ int comm_init_lpc(void)
 
 	} else if (i & EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED) {
 		/* Protocol version 2 */
-		ec_command = ec_command_lpc;
+		ec_command_proto = ec_command_lpc;
 		ec_max_outsize = ec_max_insize = EC_PROTO2_MAX_PARAM_SIZE;
 
 	} else {

util/ectool.c

@@ -25,12 +25,13 @@
 
 /* Command line options */
 enum {
-	OPT_HELP = '?',
 	OPT_DEV = 1000,
+	OPT_INTERFACE,
 };
 
 static struct option long_opts[] = {
 	{"dev", 1, 0, OPT_DEV},
+	{"interface", 1, 0, OPT_INTERFACE},
 	{NULL, 0, 0, 0}
 };
 
@@ -216,7 +217,8 @@ int parse_bool(const char *s, int *dest)
 
 void print_help(const char *prog, int print_cmds)
 {
-	printf("Usage: %s [--dev=n] <command> [params]\n\n",
+	printf("Usage: %s [--dev=n] [--interface=dev|lpc|i2c] <command> "
+	       "[params]\n\n",
 	       prog);
 	if (print_cmds)
 		puts(help_str);
@@ -4540,6 +4542,7 @@ int main(int argc, char *argv[])
 {
 	const struct command *cmd;
 	int dev = 0;
+	int interfaces = COMM_ALL;
 	int rv = 1;
 	int parse_error = 0;
 	char *e;
@@ -4561,6 +4564,19 @@ int main(int argc, char *argv[])
 				parse_error = 1;
 			}
 			break;
+
+		case OPT_INTERFACE:
+			if (!strcasecmp(optarg, "dev")) {
+				interfaces = COMM_DEV;
+			} else if (!strcasecmp(optarg, "lpc")) {
+				interfaces = COMM_LPC;
+			} else if (!strcasecmp(optarg, "i2c")) {
+				interfaces = COMM_I2C;
+			} else {
+				fprintf(stderr, "Invalid --interface\n");
+				parse_error = 1;
+			}
+			break;
 		}
 	}
 
@@ -4574,11 +4590,10 @@ int main(int argc, char *argv[])
 		exit(1);
 	}
 
-	/*
-	 * --dev support is coming in the next patch.  For now this is a
-	 * placeholder used in testing getopt_long()
-	 */
-	if (dev != 0) {
+	/* Handle sub-devices command offset */
+	if (dev > 0 && dev < 4) {
+		set_command_offset(EC_CMD_PASSTHRU_OFFSET(dev));
+	} else if (dev != 0) {
 		fprintf(stderr, "Bad device number %d\n", dev);
 		parse_error = 1;
 	}
@@ -4593,7 +4608,7 @@ int main(int argc, char *argv[])
 		exit(1);
 	}
 
-	if (comm_init()) {
+	if (comm_init(interfaces)) {
 		fprintf(stderr, "Couldn't find EC\n");
 		goto out;
 	}