Add driver for TI BQ24773 charger

Add support TI BQ24773 1S/2S/3S NVDC battery charger.

This is not a "Smart Battery" compliant charger IC, it should and cannot
use the sbc_ helpers.

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

BRANCH=none
BUG=none
TEST=on FruitPie, run "charger" command on the EC console,
add the charger task and see the battery charging.

Change-Id: I6f470184f0ce424a05007e493d802dcdb2156477
Reviewed-on: https://chromium-review.googlesource.com/191212
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>

4 files changed, 227 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index f9c31b143b..ab637f03e2 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -24,6 +24,7 @@ driver-$(CONFIG_CHARGER_BQ24707A)+=charger/bq24707a.o
 driver-$(CONFIG_CHARGER_BQ24715)+=charger/bq24715.o
 driver-$(CONFIG_CHARGER_BQ24725)+=charger/bq24725.o
 driver-$(CONFIG_CHARGER_BQ24738)+=charger/bq24738.o
+driver-$(CONFIG_CHARGER_BQ24773)+=charger/bq24773.o
 
 # LED drivers
 driver-$(CONFIG_LED_DRIVER_DS2413)+=led/ds2413.o
diff --git a/driver/charger/bq24773.c b/driver/charger/bq24773.c
new file mode 100644
index 0000000000..854bb6dfb0
--- /dev/null
+++ b/driver/charger/bq24773.c
@@ -0,0 +1,194 @@
+/* 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 bq24773 battery charger driver.
+ */
+
+#include "battery_smart.h"
+#include "bq24773.h"
+#include "charger.h"
+#include "console.h"
+#include "common.h"
+#include "i2c.h"
+#include "util.h"
+
+/*
+ * on the I2C version of the charger,
+ * some registers are 8-bit only (eg input current)
+ * and they are shifted by 6 bits compared to the SMBUS version (bq24770).
+ */
+#define REG8_SHIFT 6
+#define R8 (1 << (REG8_SHIFT))
+/* Sense resistor configurations and macros */
+#define DEFAULT_SENSE_RESISTOR 10
+#define R_SNS CONFIG_CHARGER_SENSE_RESISTOR
+#define R_AC  (CONFIG_CHARGER_SENSE_RESISTOR_AC)
+#define REG_TO_CURRENT(REG, RS) ((REG) * DEFAULT_SENSE_RESISTOR / (RS))
+#define CURRENT_TO_REG(CUR, RS) ((CUR) * (RS) / DEFAULT_SENSE_RESISTOR)
+#define REG8_TO_CURRENT(REG, RS) ((REG) * DEFAULT_SENSE_RESISTOR / (RS) * R8)
+#define CURRENT_TO_REG8(CUR, RS) ((CUR) * (RS) / DEFAULT_SENSE_RESISTOR / R8)
+
+/* Charger parameters */
+static const struct charger_info bq24773_charger_info = {
+	.name         = "bq24773",
+	.voltage_max  = 19200,
+	.voltage_min  = 1024,
+	.voltage_step = 16,
+	.current_max  = REG_TO_CURRENT(0x1FC0, R_SNS),
+	.current_min  = REG_TO_CURRENT(128, R_SNS),
+	.current_step = REG_TO_CURRENT(64, R_SNS),
+	.input_current_max  = REG8_TO_CURRENT(0x7F, R_AC),
+	.input_current_min  = REG8_TO_CURRENT(2, R_AC),
+	.input_current_step = REG8_TO_CURRENT(1, R_AC),
+};
+
+/* bq24773 specific interfaces */
+
+int charger_set_input_current(int input_current)
+{
+	return i2c_write8(I2C_PORT_CHARGER, BQ24773_ADDR,
+			  BQ24773_INPUT_CURRENT,
+			  CURRENT_TO_REG8(input_current, R_AC));
+}
+
+int charger_get_input_current(int *input_current)
+{
+	int rv;
+	int reg;
+
+	rv = i2c_read8(I2C_PORT_CHARGER, BQ24773_ADDR,
+			BQ24773_INPUT_CURRENT, &reg);
+	if (rv)
+		return rv;
+
+	*input_current = REG8_TO_CURRENT(reg, R_AC);
+
+	return EC_SUCCESS;
+}
+
+int charger_manufacturer_id(int *id)
+{
+	*id = 0x40; /* TI */
+	return EC_SUCCESS;
+}
+
+int charger_device_id(int *id)
+{
+	return i2c_read8(I2C_PORT_CHARGER, BQ24773_ADDR,
+			 BQ24773_DEVICE_ADDRESS, id);
+}
+
+int charger_get_option(int *option)
+{
+	return i2c_read16(I2C_PORT_CHARGER, BQ24773_ADDR,
+			 BQ24773_CHARGE_OPTION0, option);
+}
+
+int charger_set_option(int option)
+{
+	return i2c_write16(I2C_PORT_CHARGER, BQ24773_ADDR,
+			  BQ24773_CHARGE_OPTION0, option);
+}
+
+/* Charger interfaces */
+
+const struct charger_info *charger_get_info(void)
+{
+	return &bq24773_charger_info;
+}
+
+int charger_get_status(int *status)
+{
+	int rv;
+	int option;
+
+	rv = charger_get_option(&option);
+	if (rv)
+		return rv;
+
+	/* Default status */
+	*status = CHARGER_LEVEL_2;
+
+	if (option & OPTION0_CHARGE_INHIBIT)
+		*status |= CHARGER_CHARGE_INHIBITED;
+
+	return EC_SUCCESS;
+}
+
+int charger_set_mode(int mode)
+{
+	int rv;
+	int option;
+
+	rv = charger_get_option(&option);
+	if (rv)
+		return rv;
+
+	if (mode & CHARGE_FLAG_INHIBIT_CHARGE)
+		option |= OPTION0_CHARGE_INHIBIT;
+	else
+		option &= ~OPTION0_CHARGE_INHIBIT;
+	return charger_set_option(option);
+}
+
+int charger_get_current(int *current)
+{
+	int rv;
+	int reg;
+
+	rv = i2c_read16(I2C_PORT_CHARGER, BQ24773_ADDR,
+			BQ24773_CHARGE_CURRENT, &reg);
+	if (rv)
+		return rv;
+
+	*current = REG_TO_CURRENT(reg, R_SNS);
+	return EC_SUCCESS;
+}
+
+int charger_set_current(int current)
+{
+	current = charger_closest_current(current);
+
+	return i2c_write16(I2C_PORT_CHARGER, BQ24773_ADDR,
+		BQ24773_CHARGE_CURRENT, CURRENT_TO_REG(current, R_SNS));
+}
+
+int charger_get_voltage(int *voltage)
+{
+	return i2c_read16(I2C_PORT_CHARGER, BQ24773_ADDR,
+			  BQ24773_MAX_CHARGE_VOLTAGE, voltage);
+}
+
+int charger_set_voltage(int voltage)
+{
+	return i2c_write16(I2C_PORT_CHARGER, BQ24773_ADDR,
+			   BQ24773_MAX_CHARGE_VOLTAGE, voltage);
+}
+
+/* Charging power state initialization */
+int charger_post_init(void)
+{
+	int rv;
+
+	/* Set charger input current limit */
+	rv = charger_set_input_current(CONFIG_CHARGER_INPUT_CURRENT);
+	return rv;
+}
+
+int charger_discharge_on_ac(int enable)
+{
+	int rv;
+	int option;
+
+	rv = charger_get_option(&option);
+	if (rv)
+		return rv;
+
+	if (enable)
+		rv = charger_set_option(option | OPTION0_LEARN_ENABLE);
+	else
+		rv = charger_set_option(option & ~OPTION0_LEARN_ENABLE);
+
+	return rv;
+}
diff --git a/driver/charger/bq24773.h b/driver/charger/bq24773.h
new file mode 100644
index 0000000000..cce3e7e902
--- /dev/null
+++ b/driver/charger/bq24773.h
@@ -0,0 +1,31 @@
+/* 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 bq24773 battery charger driver.
+ */
+
+#ifndef __CROS_EC_CHARGER_BQ24773_H
+#define __CROS_EC_CHARGER_BQ24773_H
+
+/* I2C address */
+#define BQ24773_ADDR (0x6a << 1)
+
+/* Chip specific commands */
+#define BQ24773_CHARGE_OPTION0          0x00
+#define BQ24773_CHARGE_OPTION1          0x02
+#define BQ24773_PROTECT_OPTION0         0x04
+#define BQ24773_PROTECT_OPTION1         0x06
+#define BQ24773_PROTECT_STATUS          0x08
+#define BQ24773_DEVICE_ADDRESS          0x09
+#define BQ24773_CHARGE_CURRENT          0x0A
+#define BQ24773_MAX_CHARGE_VOLTAGE      0x0C
+#define BQ24773_MIN_SYSTEM_VOLTAGE      0x0E
+#define BQ24773_INPUT_CURRENT           0x0F
+#define BQ24773_CHARGE_OPTION2          0x10
+
+/* Option bits */
+#define OPTION0_CHARGE_INHIBIT          (1 << 0)
+#define OPTION0_LEARN_ENABLE            (1 << 5)
+
+#endif /* __CROS_EC_CHARGER_BQ24773_H */
diff --git a/include/config.h b/include/config.h
index bd0f2be9dd..7a882c3fcb 100644
--- a/include/config.h
+++ b/include/config.h
@@ -172,6 +172,7 @@
 #undef CONFIG_CHARGER_BQ24715
 #undef CONFIG_CHARGER_BQ24725
 #undef CONFIG_CHARGER_BQ24738
+#undef CONFIG_CHARGER_BQ24773
 #undef CONFIG_CHARGER_TPS65090  /* Note: does not use CONFIG_CHARGER */
 
 /*