add INA231 driver

Add a driver for INA231 Power/Current monitoring I2C chip.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=chrome-os-partner:28337
TEST=make BOARD=twinkie
and run "ina" command on Twinkie.

Change-Id: Id322aca74cbb6bbf866aed22e7815c0e01951414
Reviewed-on: https://chromium-review.googlesource.com/202205
Reviewed-by: Todd Broch <tbroch@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>

3 files changed, 239 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index ff6bdf6933..74c4bb6e3f 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -28,6 +28,9 @@ driver-$(CONFIG_CHARGER_BQ24735)+=charger/bq24735.o
 driver-$(CONFIG_CHARGER_BQ24738)+=charger/bq24738.o
 driver-$(CONFIG_CHARGER_BQ24773)+=charger/bq24773.o
 
+# Current/Power monitor
+driver-$(CONFIG_INA231)+=ina231.o
+
 # LED drivers
 driver-$(CONFIG_LED_DRIVER_DS2413)+=led/ds2413.o
 driver-$(CONFIG_LED_DRIVER_LP5562)+=led/lp5562.o
diff --git a/driver/ina231.c b/driver/ina231.c
new file mode 100644
index 0000000000..73f03910e2
--- /dev/null
+++ b/driver/ina231.c
@@ -0,0 +1,146 @@
+/* Copyright (c) 2014 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.
+ *
+ * TI INA231 Current/Power monitor driver.
+ */
+
+#include "console.h"
+#include "hooks.h"
+#include "i2c.h"
+#include "system.h"
+#include "timer.h"
+#include "ina231.h"
+#include "uart.h"
+#include "util.h"
+
+/* Console output macros */
+#define CPRINTS(format, args...) cprints(CC_USBCHARGE, format, ## args)
+
+/* 8-bit I2C base address */
+#define INA231_I2C_ADDR (0x40 << 1)
+
+uint16_t ina231_read(uint8_t idx, uint8_t reg)
+{
+	int res;
+	int val;
+	uint8_t addr = INA231_I2C_ADDR | (idx << 1);
+
+	res = i2c_read16(I2C_PORT_MASTER, addr, reg, &val);
+	if (res) {
+		CPRINTS("INA231 I2C read failed");
+		return 0x0bad;
+	}
+	return (val >> 8) | ((val & 0xff) << 8);
+}
+
+int ina231_write(uint8_t idx, uint8_t reg, uint16_t val)
+{
+	int res;
+	uint8_t addr = INA231_I2C_ADDR | (idx << 1);
+	uint16_t be_val = (val >> 8) | ((val & 0xff) << 8);
+
+	res = i2c_write16(I2C_PORT_MASTER, addr, reg, be_val);
+	if (res)
+		CPRINTS("INA231 I2C write failed");
+	return res;
+}
+
+int ina231_init(uint8_t idx, uint16_t config, uint16_t calib)
+{
+	int res;
+
+	res = ina231_write(idx, INA231_REG_CONFIG, config);
+	/* TODO(crosbug.com/p/29730): assume 1mA/LSB, revisit later */
+	res |= ina231_write(idx, INA231_REG_CALIB, calib);
+
+	return res;
+}
+
+int ina231_get_voltage(uint8_t idx)
+{
+	uint16_t bv = ina231_read(idx, INA231_REG_BUS_VOLT);
+	/* Bus voltage LSB : 1.25mV / bit */
+	return INA231_BUS_MV((int)bv);
+}
+
+int ina231_get_current(uint8_t idx)
+{
+	int16_t curr = ina231_read(idx, INA231_REG_CURRENT);
+	/* Current calibration: LSB = 1mA/bit */
+	return (int)curr;
+}
+
+int ina231_get_power(uint8_t idx)
+{
+	uint16_t pow = ina231_read(idx, INA231_REG_POWER);
+	/* When current LSB = 1mA/bit, power LSB is 25mW/bit */
+	return INA231_POW_MW((int)pow);
+}
+
+static void ina231_dump(uint8_t idx)
+{
+	uint16_t cfg = ina231_read(idx, INA231_REG_CONFIG);
+	int16_t sv = ina231_read(idx, INA231_REG_SHUNT_VOLT);
+	uint16_t bv = ina231_read(idx, INA231_REG_BUS_VOLT);
+	uint16_t pow = ina231_read(idx, INA231_REG_POWER);
+	int16_t curr = ina231_read(idx, INA231_REG_CURRENT);
+	uint16_t calib = ina231_read(idx, INA231_REG_CALIB);
+	uint16_t mask = ina231_read(idx, INA231_REG_MASK);
+	uint16_t alert = ina231_read(idx, INA231_REG_ALERT);
+
+	ccprintf("Configuration: %04x\n", cfg);
+	ccprintf("Shunt voltage: %04x => %d uV\n", sv, (int)sv * 25 / 10);
+	ccprintf("Bus voltage  : %04x => %d mV\n", bv, INA231_BUS_MV((int)bv));
+	ccprintf("Power        : %04x => %d mW\n", pow, INA231_POW_MW(pow));
+	ccprintf("Current      : %04x => %d mA\n", curr, curr);
+	ccprintf("Calibration  : %04x\n", calib);
+	ccprintf("Mask/Enable  : %04x\n", mask);
+	ccprintf("Alert limit  : %04x\n", alert);
+}
+
+/*****************************************************************************/
+/* Console commands */
+
+static int command_ina(int argc, char **argv)
+{
+	char *e;
+	int idx;
+	uint16_t val;
+
+	if (argc < 2)
+		return EC_ERROR_PARAM_COUNT;
+
+	idx = strtoi(argv[1], &e, 10);
+	if (*e)
+		return EC_ERROR_PARAM1;
+
+	if (2 == argc) { /* dump all registers */
+		ina231_dump(idx);
+		return EC_SUCCESS;
+	} else if (4 == argc) {
+		val = strtoi(argv[3], &e, 16);
+		if (*e)
+			return EC_ERROR_PARAM3;
+
+		if (!strcasecmp(argv[2], "config")) {
+			ina231_write(idx, INA231_REG_CONFIG, val);
+		} else if (!strcasecmp(argv[2], "calib")) {
+			ina231_write(idx, INA231_REG_CALIB, val);
+		} else if (!strcasecmp(argv[2], "mask")) {
+			ina231_write(idx, INA231_REG_MASK, val);
+		} else if (!strcasecmp(argv[2], "alert")) {
+			ina231_write(idx, INA231_REG_ALERT, val);
+		} else { /* read one register */
+			ccprintf("Invalid register: %s\n", argv[1]);
+			return EC_ERROR_INVAL;
+		}
+		return EC_SUCCESS;
+	}
+
+	return EC_ERROR_INVAL;
+}
+DECLARE_CONSOLE_COMMAND(ina, command_ina,
+			"[config|calib|mask|alert <val>]",
+			"INA231 power/current sensing",
+			NULL);
diff --git a/driver/ina231.h b/driver/ina231.h
new file mode 100644
index 0000000000..56ccb27d4e
--- /dev/null
+++ b/driver/ina231.h
@@ -0,0 +1,90 @@
+/* Copyright (c) 2014 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.
+ *
+ * TI INA231 Current/Power monitor driver.
+ */
+
+#ifndef INA231_H
+#define INA231_H
+
+#define INA231_REG_CONFIG     0x00
+#define INA231_REG_SHUNT_VOLT 0x01
+#define INA231_REG_BUS_VOLT   0x02
+#define INA231_REG_POWER      0x03
+#define INA231_REG_CURRENT    0x04
+#define INA231_REG_CALIB      0x05
+#define INA231_REG_MASK       0x06
+#define INA231_REG_ALERT      0x07
+
+#define INA231_CONFIG_MODE_MASK     (7 << 0)
+#define INA231_CONFIG_MODE_PWRDWN   (0 << 0)
+#define INA231_CONFIG_MODE_SHUNT    (1 << 0)
+#define INA231_CONFIG_MODE_BUS      (1 << 1)
+#define INA231_CONFIG_MODE_TRG      (0 << 2)
+#define INA231_CONFIG_MODE_CONT     (1 << 2)
+
+/* Conversion time for bus and shunt in micro-seconds */
+enum ina231_conv_time {
+	INA231_CONV_TIME_140  = 0x00,
+	INA231_CONV_TIME_204  = 0x01,
+	INA231_CONV_TIME_332  = 0x02,
+	INA231_CONV_TIME_588  = 0x03,
+	INA231_CONV_TIME_1100 = 0x04,
+	INA231_CONV_TIME_2116 = 0x05,
+	INA231_CONV_TIME_4156 = 0x06,
+	INA231_CONV_TIME_8244 = 0x07,
+};
+#define INA231_CONV_TIME_MASK 0x7
+#define INA231_CONFIG_SHUNT_CONV_TIME(t) ((t) << 3)
+#define INA231_CONFIG_BUS_CONV_TIME(t)   ((t) << 6)
+
+#define INA231_CONFIG_AVG_1        (0 << 9)
+#define INA231_CONFIG_AVG_4        (1 << 9)
+#define INA231_CONFIG_AVG_16       (2 << 9)
+#define INA231_CONFIG_AVG_64       (3 << 9)
+#define INA231_CONFIG_AVG_128      (4 << 9)
+#define INA231_CONFIG_AVG_256      (5 << 9)
+#define INA231_CONFIG_AVG_512      (6 << 9)
+#define INA231_CONFIG_AVG_1024     (7 << 9)
+
+#define INA231_MASK_EN_LEN         (1 << 0)
+#define INA231_MASK_EN_APOL        (1 << 1)
+#define INA231_MASK_EN_OVF         (1 << 2)
+#define INA231_MASK_EN_CVRF        (1 << 3)
+#define INA231_MASK_EN_AFF         (1 << 4)
+#define INA231_MASK_EN_CNVR        (1 << 10)
+#define INA231_MASK_EN_POL         (1 << 11)
+#define INA231_MASK_EN_BUL         (1 << 12)
+#define INA231_MASK_EN_BOL         (1 << 13)
+#define INA231_MASK_EN_SUL         (1 << 14)
+#define INA231_MASK_EN_SOL        (1 << 15)
+
+/* Calibration value to get current LSB = 1mA */
+#define INA231_CALIB_1MA(rsense_mohm) (5120/(rsense_mohm))
+
+/* Bus voltage LSB : 1.25mV / bit */
+#define INA231_BUS_MV(reg) ((reg) * 125 / 100)
+
+/* Power LSB : 25mW / current_lsb */
+#define INA231_POW_MW(reg) ((reg) * 25 * 1/*Current mA/LSB*/)
+
+/* Read INA231 register. */
+uint16_t ina231_read(uint8_t idx, uint8_t reg);
+
+/* Write INA231 register. */
+int ina231_write(uint8_t idx, uint8_t reg, uint16_t val);
+
+/* Set measurement parameters */
+int ina231_init(uint8_t idx, uint16_t config, uint16_t calib);
+
+/* Return bus voltage in milliVolts */
+int ina231_get_voltage(uint8_t idx);
+
+/* Return current in milliAmps */
+int ina231_get_current(uint8_t idx);
+
+/* Return power in milliWatts */
+int ina231_get_power(uint8_t idx);
+
+#endif /* INA231_H */