Add I2C read/write host command

These commands are only available when system is unlocked.

BUG=chrome-os-partner:9716
TEST=When system is unlocked, check we can read/write I2C bus.
     When system is locked, check the commands return error.

Change-Id: I8c4a8a42ab13d62c7e47bf33e2a7abc6f61e43fa
Reviewed-on: https://gerrit.chromium.org/gerrit/27254
Reviewed-by: Rong Chang <rongchang@chromium.org>
Commit-Ready: Vic Yang <victoryang@chromium.org>
Tested-by: Vic Yang <victoryang@chromium.org>

4 files changed, 191 insertions, 0 deletions

diff --git a/common/build.mk b/common/build.mk
index bfdeb11058..f20e968933 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -14,6 +14,7 @@ common-$(CONFIG_CHARGER_BQ24725)+=charger_bq24725.o
 common-$(CONFIG_PMU_TPS65090)+=pmu_tps65090.o pmu_tps65090_charger.o
 common-$(CONFIG_EOPTION)+=eoption.o
 common-$(CONFIG_FLASH)+=flash_common.o flash_commands.o fmap.o
+common-$(CONFIG_I2C)+=i2c_commands.o
 common-$(CONFIG_IR357x)+=ir357x.o
 common-$(CONFIG_LPC)+=port80.o
 common-$(CONFIG_POWER_LED)+=power_led.o
diff --git a/common/i2c_commands.c b/common/i2c_commands.c
new file mode 100644
index 0000000000..6111b8ac7b
--- /dev/null
+++ b/common/i2c_commands.c
@@ -0,0 +1,55 @@
+/* Copyright (c) 2012 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.
+ */
+
+/* I2C host commands for Chrome EC */
+
+#include "host_command.h"
+#include "i2c.h"
+#include "system.h"
+
+int i2c_command_read(struct host_cmd_handler_args *args)
+{
+	const struct ec_params_i2c_read *p =
+		(const struct ec_params_i2c_read *)args->params;
+	struct ec_response_i2c_read *r =
+		(struct ec_response_i2c_read *)args->response;
+	int data, rv = -1;
+
+	if (system_is_locked())
+		return EC_RES_ACCESS_DENIED;
+
+	if  (p->read_size == 16)
+		rv = i2c_read16(p->port, p->addr, p->offset, &data);
+	else if (p->read_size == 8)
+		rv = i2c_read8(p->port, p->addr, p->offset, &data);
+
+	if (rv)
+		return EC_RES_ERROR;
+	r->data = data;
+
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_I2C_READ, i2c_command_read, EC_VER_MASK(0));
+
+int i2c_command_write(struct host_cmd_handler_args *args)
+{
+	const struct ec_params_i2c_write *p =
+		(const struct ec_params_i2c_write *)args->params;
+	int rv = -1;
+
+	if (system_is_locked())
+		return EC_RES_ACCESS_DENIED;
+
+	if (p->write_size == 16)
+		rv = i2c_write16(p->port, p->addr, p->offset, p->data);
+	else if (p->write_size == 8)
+		rv = i2c_write8(p->port, p->addr, p->offset, p->data);
+
+	if (rv)
+		return EC_RES_ERROR;
+
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_I2C_WRITE, i2c_command_write, EC_VER_MASK(0));
diff --git a/include/ec_commands.h b/include/ec_commands.h
index fb9bdc7d82..417e0a021a 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -741,6 +741,33 @@ struct ec_params_switch_enable_wireless {
 } __packed;
 
 /*****************************************************************************/
+/* I2C commands. Only available when flash write protect is unlocked. */
+
+/* Read I2C bus */
+#define EC_CMD_I2C_READ 0x94
+
+struct ec_params_i2c_read {
+	uint16_t addr;
+	uint8_t read_size; /* Either 8 or 16. */
+	uint8_t port;
+	uint8_t offset;
+} __packed;
+struct ec_response_i2c_read {
+	uint16_t data;
+} __packed;
+
+/* Write I2C bus */
+#define EC_CMD_I2C_WRITE 0x95
+
+struct ec_params_i2c_write {
+	uint16_t data;
+	uint16_t addr;
+	uint8_t write_size; /* Either 8 or 16. */
+	uint8_t port;
+	uint8_t offset;
+} __packed;
+
+/*****************************************************************************/
 /* System commands */
 
 /*
diff --git a/util/ectool.c b/util/ectool.c
index dc358ae8b9..9e3efec836 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -67,6 +67,10 @@ const char help_str[] =
 	"      Checks for basic communication with EC\n"
 	"  kbpress\n"
 	"      Simulate key press\n"
+	"  i2cread\n"
+	"      Read I2C bus\n"
+	"  i2cwrite\n"
+	"      Write I2C bus\n"
 	"  lightbar [CMDS]\n"
 	"      Various lightbar control commands\n"
 	"  pstoreinfo\n"
@@ -1471,6 +1475,108 @@ int cmd_wireless(int argc, char *argv[])
 }
 
 
+int cmd_i2c_read(int argc, char *argv[])
+{
+	struct ec_params_i2c_read p;
+	struct ec_response_i2c_read r;
+	char *e;
+	int rv;
+
+	if (argc != 5) {
+		fprintf(stderr, "Usage: %s <8 | 16> <port> <addr> <offset>\n",
+				argv[0]);
+		return -1;
+	}
+
+	p.read_size = strtol(argv[1], &e, 0);
+	if ((e && *e) || (p.read_size != 8 && p.read_size != 16)) {
+		fprintf(stderr, "Bad read size.\n");
+		return -1;
+	}
+
+	p.port = strtol(argv[2], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad port.\n");
+		return -1;
+	}
+
+	p.addr = strtol(argv[3], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad address.\n");
+		return -1;
+	}
+
+	p.offset = strtol(argv[4], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad offset.\n");
+		return -1;
+	}
+
+	rv = ec_command(EC_CMD_I2C_READ, &p, sizeof(p), &r, sizeof(r));
+
+	if (rv < 0)
+		return rv;
+
+	printf("Read from I2C port %d at 0x%x offset 0x%x = 0x%x\n",
+	       p.port, p.addr, p.offset, r.data);
+	return 0;
+}
+
+
+int cmd_i2c_write(int argc, char *argv[])
+{
+	struct ec_params_i2c_write p;
+	char *e;
+	int rv;
+
+	if (argc != 6) {
+		fprintf(stderr,
+			"Usage: %s <8 | 16> <port> <addr> <offset> <data>\n",
+			argv[0]);
+		return -1;
+	}
+
+	p.write_size = strtol(argv[1], &e, 0);
+	if ((e && *e) || (p.write_size != 8 && p.write_size != 16)) {
+		fprintf(stderr, "Bad write size.\n");
+		return -1;
+	}
+
+	p.port = strtol(argv[2], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad port.\n");
+		return -1;
+	}
+
+	p.addr = strtol(argv[3], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad address.\n");
+		return -1;
+	}
+
+	p.offset = strtol(argv[4], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad offset.\n");
+		return -1;
+	}
+
+	p.data = strtol(argv[5], &e, 0);
+	if (e && *e) {
+		fprintf(stderr, "Bad data.\n");
+		return -1;
+	}
+
+	rv = ec_command(EC_CMD_I2C_WRITE, &p, sizeof(p), NULL, 0);
+
+	if (rv < 0)
+		return rv;
+
+	printf("Wrote 0x%x to I2C port %d at 0x%x offset 0x%x.\n",
+	       p.data, p.port, p.addr, p.offset);
+	return 0;
+}
+
+
 int cmd_lcd_backlight(int argc, char *argv[])
 {
 	struct ec_params_switch_enable_backlight p;
@@ -1723,6 +1829,8 @@ const struct command commands[] = {
 	{"flashinfo", cmd_flash_info},
 	{"hello", cmd_hello},
 	{"kbpress", cmd_kbpress},
+	{"i2cread", cmd_i2c_read},
+	{"i2cwrite", cmd_i2c_write},
 	{"lightbar", cmd_lightbar},
 	{"vboot", cmd_vboot},
 	{"pstoreinfo", cmd_pstore_info},