charger/rt946x: add Richtek rt946x charger driver

BUG=chromium:736821
BRANCH=none
TEST=
1) add RT9467 config to Scarlet and build the code
2) hook up rt9467 eval board with dummy load
3) verify the i2c traffic: set voltage, set current, and
   get device id

Change-Id: Ie0dc2650711465b89eb4a5fbf69a326d6277b583
Signed-off-by: Philip Chen <philipchen@google.com>
Reviewed-on: https://chromium-review.googlesource.com/565055
Commit-Ready: Philip Chen <philipchen@chromium.org>
Tested-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Shawn N <shawnn@chromium.org>

4 files changed, 959 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index 074fa9e1e9..d4dbd19100 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -50,6 +50,8 @@ driver-$(CONFIG_CHARGER_BQ25892)+=charger/bq2589x.o
 driver-$(CONFIG_CHARGER_BQ25895)+=charger/bq2589x.o
 driver-$(CONFIG_CHARGER_ISL9237)+=charger/isl923x.o
 driver-$(CONFIG_CHARGER_ISL9238)+=charger/isl923x.o
+driver-$(CONFIG_CHARGER_RT9466)+=charger/rt946x.o
+driver-$(CONFIG_CHARGER_RT9467)+=charger/rt946x.o
 
 # I/O expander
 driver-$(CONFIG_IO_EXPANDER_PCA9534)+=ioexpander_pca9534.o
diff --git a/driver/charger/rt946x.c b/driver/charger/rt946x.c
new file mode 100644
index 0000000000..0a630e4ffa
--- /dev/null
+++ b/driver/charger/rt946x.c
@@ -0,0 +1,715 @@
+/* Copyright 2017 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.
+ *
+ * Richtek rt946x battery charger driver.
+ */
+
+#include "battery_smart.h"
+#include "charger.h"
+#include "common.h"
+#include "compile_time_macros.h"
+#include "config.h"
+#include "console.h"
+#include "hooks.h"
+#include "i2c.h"
+#include "printf.h"
+#include "rt946x.h"
+#include "task.h"
+#include "timer.h"
+#include "util.h"
+
+/* Console output macros */
+#define CPRINTF(format, args...) cprintf(CC_CHARGER, format, ## args)
+
+/* Charger parameters */
+static const struct charger_info rt946x_charger_info = {
+	.name         = CHARGER_NAME,
+	.voltage_max  = CHARGE_V_MAX,
+	.voltage_min  = CHARGE_V_MIN,
+	.voltage_step = CHARGE_V_STEP,
+	.current_max  = CHARGE_I_MAX,
+	.current_min  = CHARGE_I_MIN,
+	.current_step = CHARGE_I_STEP,
+	.input_current_max  = INPUT_I_MAX,
+	.input_current_min  = INPUT_I_MIN,
+	.input_current_step = INPUT_I_STEP,
+};
+
+struct charger_init_setting {
+	uint16_t eoc_current;
+	uint16_t mivr;
+	uint16_t ircmp_vclamp;
+	uint16_t ircmp_res;
+	uint16_t boost_voltage;
+	uint16_t boost_current;
+};
+
+static const struct charger_init_setting rt946x_charger_init_setting = {
+	.eoc_current = 250,
+	.mivr = 4400,
+	.ircmp_vclamp = 32,
+	.ircmp_res = 25,
+	.boost_voltage = 5050,
+	.boost_current = 500,
+};
+
+enum rt946x_ilmtsel {
+	RT946X_ILMTSEL_PSEL_OTG,
+	RT946X_ILMTSEL_AICR = 2,
+	RT946X_ILMTSEL_LOWER_LEVEL, /* lower of above two */
+};
+
+enum rt946x_irq {
+	RT946X_IRQ_CHGSTATC = 0,
+	RT946X_IRQ_CHGFAULT,
+	RT946X_IRQ_TSSTATC,
+	RT946X_IRQ_CHGIRQ1,
+	RT946X_IRQ_CHGIRQ2,
+	RT946X_IRQ_CHGIRQ3,
+#ifdef CONFIG_CHARGER_RT9467
+	RT946X_IRQ_DPDMIRQ,
+#endif
+	RT946X_IRQ_COUNT,
+};
+
+static uint8_t rt946x_irqmask[RT946X_IRQ_COUNT] = {
+	0xF0, 0xF0, 0xFF, 0xFF, 0xFF, 0xFF,
+#ifdef CONFIG_CHARGER_RT9467
+	0xFF,
+#endif
+};
+
+static const uint8_t rt946x_irq_maskall[RT946X_IRQ_COUNT] = {
+	0xF0, 0xF0, 0xFF, 0xFF, 0xFF, 0xFF,
+#ifdef CONFIG_CHARGER_RT9467
+	0xFF,
+#endif
+};
+
+static const uint16_t rt946x_boost_current[] = {
+	500, 700, 1100, 1300, 1800, 2100, 2400, 3000,
+};
+
+static int rt946x_read8(int reg, int *val)
+{
+	return i2c_read8(I2C_PORT_CHARGER, RT946X_ADDR, reg, val);
+}
+
+static int rt946x_write8(int reg, int val)
+{
+	return i2c_write8(I2C_PORT_CHARGER, RT946X_ADDR, reg, val);
+}
+
+static int rt946x_block_read(int reg, uint8_t *val, int len)
+{
+	return i2c_read_string(I2C_PORT_CHARGER, RT946X_ADDR, reg, val, len);
+}
+
+static int rt946x_block_write(int reg, const uint8_t *val, int len)
+{
+	int rv;
+	uint8_t buf[I2C_MAX_HOST_PACKET_SIZE];
+
+	if (len + 1 > I2C_MAX_HOST_PACKET_SIZE)
+		return EC_ERROR_INVAL;
+
+	buf[0] = reg & 0xff;
+	memcpy(&buf[1], val, len);
+
+	i2c_lock(I2C_PORT_CHARGER, 1);
+	rv = i2c_xfer(I2C_PORT_CHARGER, RT946X_ADDR, buf, len + 1, NULL, 0,
+		      I2C_XFER_SINGLE);
+	i2c_lock(I2C_PORT_CHARGER, 0);
+	return rv;
+}
+
+static int rt946x_update_bits(int reg, int mask, int val)
+{
+	int rv;
+	int reg_val = 0;
+
+	rv = rt946x_read8(reg, &reg_val);
+	if (rv)
+		return rv;
+	reg_val &= ~mask;
+	reg_val |= (mask & val);
+	rv = rt946x_write8(reg, reg_val);
+	return rv;
+}
+
+static inline int rt946x_set_bit(int reg, int mask)
+{
+	return rt946x_update_bits(reg, mask, mask);
+}
+
+static inline int rt946x_clr_bit(int reg, int mask)
+{
+	return rt946x_update_bits(reg, mask, 0x00);
+}
+
+static inline uint8_t rt946x_closest_reg(uint16_t min, uint16_t max,
+					 uint16_t step, uint16_t target)
+{
+	if (target < min)
+		return 0;
+	if (target >= max)
+		return ((max - min) / step);
+	return (target - min) / step;
+}
+
+static uint8_t rt946x_closest_reg_via_tbl(const uint16_t *tbl, uint16_t target)
+{
+	int i = 0;
+
+	if (target < tbl[0])
+		return 0;
+	for (i = 0; i < ARRAY_SIZE(tbl) - 1; i++) {
+		if (target >= tbl[i] && target < tbl[i + 1])
+			return i;
+	}
+	return ARRAY_SIZE(tbl) - 1;
+}
+
+static int rt946x_chip_rev(int *chip_rev)
+{
+	int rv;
+
+	rv = rt946x_read8(RT946X_REG_DEVICEID, chip_rev);
+	if (rv == EC_SUCCESS)
+		*chip_rev &= RT946X_MASK_CHIP_REV;
+	return rv;
+}
+
+static inline int rt946x_enable_wdt(int en)
+{
+	return (en ? rt946x_set_bit : rt946x_clr_bit)
+		(RT946X_REG_CHGCTRL13, RT946X_MASK_WDT_EN);
+}
+
+static inline int rt946x_enable_hz(int en)
+{
+	return (en ? rt946x_set_bit : rt946x_clr_bit)
+		(RT946X_REG_CHGCTRL1, RT946X_MASK_HZ_EN);
+}
+
+static int rt946x_por_reset(void)
+{
+	int rv = 0;
+
+	rv = rt946x_enable_hz(0);
+	if (rv)
+		return rv;
+
+	return rt946x_set_bit(RT946X_REG_CORECTRL0, RT946X_MASK_RST);
+}
+
+static int rt946x_reset_to_zero(void)
+{
+	int rv = 0;
+
+	rv = charger_set_current(0);
+	if (rv)
+		return rv;
+
+	rv = charger_set_voltage(0);
+	if (rv)
+		return rv;
+
+	return rt946x_enable_hz(1);
+}
+
+static int rt946x_enable_bc12_detection(int en)
+{
+#ifdef CONFIG_CHARGER_RT9467
+	return (en ? rt946x_set_bit : rt946x_clr_bit)
+		(RT946X_REG_DPDM1, RT946X_MASK_USBCHGEN);
+#endif
+	return 0;
+}
+
+static int rt946x_set_ieoc(unsigned int ieoc)
+{
+	uint8_t reg_ieoc = 0;
+
+	reg_ieoc = rt946x_closest_reg(RT946X_IEOC_MIN, RT946X_IEOC_MAX,
+		RT946X_IEOC_STEP, ieoc);
+
+	CPRINTF("%s ieoc = %d(0x%02X)\n", __func__, ieoc, reg_ieoc);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL9, RT946X_MASK_IEOC,
+		reg_ieoc << RT946X_SHIFT_IEOC);
+}
+
+static int rt946x_set_mivr(unsigned int mivr)
+{
+	uint8_t reg_mivr = 0;
+
+	reg_mivr = rt946x_closest_reg(RT946X_MIVR_MIN, RT946X_MIVR_MAX,
+		RT946X_MIVR_STEP, mivr);
+
+	CPRINTF("%s: mivr = %d(0x%02X)\n", __func__, mivr, reg_mivr);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL6, RT946X_MASK_MIVR,
+		reg_mivr << RT946X_SHIFT_MIVR);
+}
+
+static int rt946x_set_boost_voltage(unsigned int voltage)
+{
+	uint8_t reg_voltage = 0;
+
+	reg_voltage = rt946x_closest_reg(RT946X_BOOST_VOLTAGE_MIN,
+		RT946X_BOOST_VOLTAGE_MAX, RT946X_BOOST_VOLTAGE_STEP, voltage);
+
+	CPRINTF("%s voltage = %d(0x%02X)\n", __func__, voltage, reg_voltage);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL5,
+		RT946X_MASK_BOOST_VOLTAGE,
+		reg_voltage << RT946X_SHIFT_BOOST_VOLTAGE);
+}
+
+static int rt946x_set_boost_current(unsigned int current)
+{
+	uint8_t reg_current = 0;
+
+	reg_current = rt946x_closest_reg_via_tbl(rt946x_boost_current, current);
+
+	CPRINTF("%s current = %d(0x%02X)\n", __func__, current, reg_current);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL10,
+		RT946X_MASK_BOOST_CURRENT,
+		reg_current << RT946X_SHIFT_BOOST_CURRENT);
+}
+
+static int rt946x_set_ircmp_vclamp(unsigned int vclamp)
+{
+	uint8_t reg_vclamp = 0;
+
+	reg_vclamp = rt946x_closest_reg(RT946X_IRCMP_VCLAMP_MIN,
+		RT946X_IRCMP_VCLAMP_MAX, RT946X_IRCMP_VCLAMP_STEP, vclamp);
+
+	CPRINTF("%s: vclamp = %d(0x%02X)\n", __func__, vclamp, reg_vclamp);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL18,
+		RT946X_MASK_IRCMP_VCLAMP,
+		reg_vclamp << RT946X_SHIFT_IRCMP_VCLAMP);
+}
+
+static int rt946x_set_ircmp_res(unsigned int res)
+{
+	uint8_t reg_res = 0;
+
+	reg_res = rt946x_closest_reg(RT946X_IRCMP_RES_MIN, RT946X_IRCMP_RES_MAX,
+		RT946X_IRCMP_RES_STEP, res);
+
+	CPRINTF("%s: res = %d(0x%02X)\n", __func__, res, reg_res);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL18, RT946X_MASK_IRCMP_RES,
+		reg_res << RT946X_SHIFT_IRCMP_RES);
+}
+
+static int rt946x_init_irq(void)
+{
+	int rv = 0;
+	uint8_t dummy[RT946X_IRQ_COUNT] = {0};
+
+	/* Mask all interrupts */
+	rv = rt946x_block_write(RT946X_REG_CHGSTATCCTRL, rt946x_irq_maskall,
+				RT946X_IRQ_COUNT);
+	if (rv)
+		return rv;
+	/* Clear all interrupt flags */
+	rv = rt946x_block_read(RT946X_REG_CHGSTATC, dummy, RT946X_IRQ_COUNT);
+	if (rv)
+		return rv;
+	/* Init interrupt */
+	return rt946x_block_write(RT946X_REG_CHGSTATCCTRL, rt946x_irqmask,
+				  ARRAY_SIZE(rt946x_irqmask));
+}
+
+static int rt946x_init_setting(void)
+{
+	int rv = 0;
+
+	/* Disable BC12 detection */
+	rv = rt946x_enable_bc12_detection(0);
+	if (rv)
+		return rv;
+	/* Disable WDT */
+	rv = rt946x_enable_wdt(0);
+	if (rv)
+		return rv;
+	rv = rt946x_set_mivr(rt946x_charger_init_setting.mivr);
+	if (rv)
+		return rv;
+	rv = rt946x_set_ieoc(rt946x_charger_init_setting.eoc_current);
+	if (rv)
+		return rv;
+	rv = rt946x_set_boost_voltage(
+		rt946x_charger_init_setting.boost_voltage);
+	if (rv)
+		return rv;
+	rv = rt946x_set_boost_current(
+		rt946x_charger_init_setting.boost_current);
+	if (rv)
+		return rv;
+	rv = rt946x_set_ircmp_vclamp(rt946x_charger_init_setting.ircmp_vclamp);
+	if (rv)
+		return rv;
+	rv = rt946x_set_ircmp_res(rt946x_charger_init_setting.ircmp_res);
+	if (rv)
+		return rv;
+	return rt946x_init_irq();
+}
+
+int charger_enable_otg_power(int enabled)
+{
+	return (enabled ? rt946x_set_bit : rt946x_clr_bit)
+		(RT946X_REG_CHGCTRL1, RT946X_MASK_OPA_MODE);
+}
+
+int charger_set_input_current(int input_current)
+{
+	uint8_t reg_iin = 0;
+	const struct charger_info * const info = charger_get_info();
+
+	reg_iin = rt946x_closest_reg(info->input_current_min,
+		info->input_current_max, info->input_current_step,
+		input_current);
+
+	CPRINTF("%s iin = %d(0x%02X)\n", __func__, input_current, reg_iin);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL3, RT946X_MASK_AICR,
+		reg_iin << RT946X_SHIFT_AICR);
+}
+
+int charger_get_input_current(int *input_current)
+{
+	int rv;
+	int val = 0;
+	const struct charger_info * const info = charger_get_info();
+
+	rv = rt946x_read8(RT946X_REG_CHGCTRL3, &val);
+	if (rv)
+		return rv;
+
+	val = (val & RT946X_MASK_AICR) >> RT946X_SHIFT_AICR;
+	*input_current = val * info->input_current_step
+		+ info->input_current_min;
+
+	return EC_SUCCESS;
+}
+
+int charger_manufacturer_id(int *id)
+{
+	return EC_ERROR_UNIMPLEMENTED;
+}
+
+int charger_device_id(int *id)
+{
+	int rv;
+
+	rv = rt946x_read8(RT946X_REG_DEVICEID, id);
+	if (rv == EC_SUCCESS)
+		*id &= RT946X_MASK_VENDOR_ID;
+	return rv;
+}
+
+int charger_get_option(int *option)
+{
+	/* Ignored: does not exist */
+	*option = 0;
+	return EC_SUCCESS;
+}
+
+int charger_set_option(int option)
+{
+	/* Ignored: does not exist */
+	return EC_SUCCESS;
+}
+
+const struct charger_info *charger_get_info(void)
+{
+	return &rt946x_charger_info;
+}
+
+int charger_get_status(int *status)
+{
+	int rv;
+	int val = 0;
+
+	rv = rt946x_read8(RT946X_REG_CHGCTRL2, &val);
+	if (rv)
+		return rv;
+	val = (val & RT946X_MASK_CHG_EN) >> RT946X_SHIFT_CHG_EN;
+	if (!val)
+		*status |= CHARGER_CHARGE_INHIBITED;
+
+	rv = rt946x_read8(RT946X_REG_CHGFAULT, &val);
+	if (rv)
+		return rv;
+	if (val & RT946X_MASK_CHG_VBATOV)
+		*status |= CHARGER_VOLTAGE_OR;
+
+
+	rv = rt946x_read8(RT946X_REG_CHGNTC, &val);
+	if (rv)
+		return rv;
+	val = (val & RT946X_MASK_BATNTC_FAULT) >> RT946X_SHIFT_BATNTC_FAULT;
+
+	switch (val) {
+	case RT946X_BATTEMP_WARM:
+		*status |= CHARGER_RES_HOT;
+		break;
+	case RT946X_BATTEMP_COOL:
+		*status |= CHARGER_RES_COLD;
+		break;
+	case RT946X_BATTEMP_COLD:
+		*status |= CHARGER_RES_COLD;
+		*status |= CHARGER_RES_UR;
+		break;
+	case RT946X_BATTEMP_HOT:
+		*status |= CHARGER_RES_HOT;
+		*status |= CHARGER_RES_OR;
+		break;
+	default:
+		break;
+	}
+
+	return EC_SUCCESS;
+}
+
+int charger_set_mode(int mode)
+{
+	int rv;
+
+	if (mode & CHARGE_FLAG_POR_RESET) {
+		rv = rt946x_por_reset();
+		if (rv)
+			return rv;
+	}
+
+	if (mode & CHARGE_FLAG_RESET_TO_ZERO) {
+		rv = rt946x_reset_to_zero();
+		if (rv)
+			return rv;
+	}
+
+	return EC_SUCCESS;
+}
+
+int charger_get_current(int *current)
+{
+	int rv;
+	int val = 0;
+	const struct charger_info * const info = charger_get_info();
+
+	rv = rt946x_read8(RT946X_REG_CHGCTRL7, &val);
+	if (rv)
+		return rv;
+
+	val = (val & RT946X_MASK_ICHG) >> RT946X_SHIFT_ICHG;
+	*current = val * info->current_step + info->current_min;
+
+	return EC_SUCCESS;
+}
+
+int charger_set_current(int current)
+{
+	uint8_t reg_icc = 0;
+	const struct charger_info * const info = charger_get_info();
+
+	reg_icc = rt946x_closest_reg(info->current_min, info->current_max,
+		info->current_step, current);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL7, RT946X_MASK_ICHG,
+		reg_icc << RT946X_SHIFT_ICHG);
+}
+
+int charger_get_voltage(int *voltage)
+{
+	int rv;
+	int val = 0;
+	const struct charger_info * const info = charger_get_info();
+
+	rv = rt946x_read8(RT946X_REG_CHGCTRL4, &val);
+	if (rv)
+		return rv;
+
+	val = (val & RT946X_MASK_CV) >> RT946X_SHIFT_CV;
+	*voltage = val * info->voltage_step + info->voltage_min;
+
+	return EC_SUCCESS;
+}
+
+int charger_set_voltage(int voltage)
+{
+	uint8_t reg_cv = 0;
+	const struct charger_info * const info = charger_get_info();
+
+	reg_cv = rt946x_closest_reg(info->voltage_min, info->voltage_max,
+		info->voltage_step, voltage);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL4, RT946X_MASK_CV,
+		reg_cv << RT946X_SHIFT_CV);
+}
+
+int charger_discharge_on_ac(int enable)
+{
+	return rt946x_enable_hz(enable);
+}
+
+int charger_get_vbus_voltage(int port)
+{
+	return EC_ERROR_UNIMPLEMENTED;
+}
+
+/* Setup sourcing current to prevent overload */
+#ifdef CONFIG_CHARGER_ILIM_PIN_DISABLED
+static int rt946x_enable_ilim_pin(int en)
+{
+	int ret;
+
+	ret = (en ? rt946x_set_bit : rt946x_clr_bit)
+		(RT946X_REG_CHGCTRL3, RT946X_MASK_ILIMEN);
+
+	return ret;
+}
+
+static int rt946x_select_ilmt(enum rt946x_ilmtsel sel)
+{
+	int ret;
+
+	ret = rt946x_update_bits(RT946X_REG_CHGCTRL2, RT946X_MASK_ILMTSEL,
+		sel << RT946X_SHIFT_ILMTSEL);
+
+	return ret;
+}
+#endif /* CONFIG_CHARGER_ILIM_PIN_DISABLED */
+
+/* Charging power state initialization */
+int charger_post_init(void)
+{
+#ifdef CONFIG_CHARGER_ILIM_PIN_DISABLED
+	int rv;
+
+	rv = rt946x_select_ilmt(RT946X_ILMTSEL_AICR);
+	if (rv)
+		return rv;
+	/* Disable ILIM pin */
+	rv = rt946x_enable_ilim(0);
+	if (rv)
+		return rv;
+#endif
+	return EC_SUCCESS;
+}
+
+/* Hardware current ramping (aka AICL: Average Input Current Level) */
+#ifdef CONFIG_CHARGE_RAMP_HW
+static int rt946x_get_mivr(int *mivr)
+{
+	int rv;
+	int val = 0;
+
+	rv = rt946x_read8(RT946X_REG_CHGCTRL6, &val);
+	if (rv)
+		return rv;
+
+	val = (val & RT946X_MASK_MIVR) >> RT946X_SHIFT_MIVR;
+	*mivr = val * RT946X_MIVR_STEP + RT946X_MIVR_MIN;
+
+	return EC_SUCCESS;
+}
+
+static int rt946x_set_aicl_vth(uint8_t aicl_vth)
+{
+	uint8_t reg_aicl_vth = 0;
+
+	reg_aicl_vth = rt946x_closest_reg(RT946X_AICLVTH_MIN,
+		RT946X_AICLVTH_MAX, RT946X_AICLVTH_STEP, aicl_vth);
+
+	return rt946x_update_bits(RT946X_REG_CHGCTRL14, RT946X_MASK_AICLVTH,
+		reg_aicl_vth << RT946X_SHIFT_AICLVTH);
+}
+
+int charger_set_hw_ramp(int enable)
+{
+	int rv;
+	unsigned int mivr = 0;
+
+	if (!enable) {
+		rv = rt946x_clr_bit(RT946X_REG_CHGCTRL14, RT946X_MASK_AICLMEAS);
+		return rv;
+	}
+
+	rv = rt946x_get_mivr(&mivr);
+	if (rv < 0)
+		return rv;
+
+	/*
+	 * Check if there's a suitable AICL_VTH.
+	 * The vendor suggests setting AICL_VTH as (MIVR + 200mV).
+	 */
+	if ((mivr + 200) > RT946X_AICLVTH_MAX) {
+		CPRINTF("%s: no suitable vth, mivr = %d\n", __func__, mivr);
+		return EC_ERROR_INVAL;
+	}
+
+	rv = rt946x_set_aicl_vth(mivr + 200);
+	if (rv < 0)
+		return rv;
+
+	return rt946x_set_bit(RT946X_REG_CHGCTRL14, RT946X_MASK_AICLMEAS);
+}
+
+int chg_ramp_is_stable(void)
+{
+	int rv;
+	int val = 0;
+
+	rv = rt946x_read8(RT946X_REG_CHGCTRL14, &val);
+	val = (val & RT946X_MASK_AICLMEAS) >> RT946X_SHIFT_AICLMEAS;
+
+	return (!rv && !val);
+}
+
+int chg_ramp_is_detected(void)
+{
+	return 1;
+}
+
+int chg_ramp_get_current_limit(void)
+{
+	int rv;
+	int input_current = 0;
+
+	rv = charger_get_input_current(&input_current);
+
+	return rv ? -1 : input_current;
+}
+#endif /* CONFIG_CHARGE_RAMP_HW */
+
+static void rt946x_init(void)
+{
+	int reg = 0xFFFFFFFF;
+
+	/* Check device id */
+	if (charger_device_id(&reg) || reg != RT946X_VENDOR_ID) {
+		CPRINTF("RT946X incorrect ID: 0x%02x\n", reg);
+		return;
+	}
+	CPRINTF("Device ID(0x%02X) found\n", RT946X_VENDOR_ID);
+
+
+	/* Check revision id */
+	if (rt946x_chip_rev(&reg) || reg < RT946X_CHIP_REV) {
+		CPRINTF("RT946X incorrect CHIP REV: 0x%02x\n", reg);
+		return;
+	}
+
+	if (rt946x_init_setting())
+		return;
+
+	CPRINTF("Device ID(0x%02X) initialized\n", RT946X_VENDOR_ID);
+}
+DECLARE_HOOK(HOOK_INIT, rt946x_init, HOOK_PRIO_LAST);
diff --git a/driver/charger/rt946x.h b/driver/charger/rt946x.h
new file mode 100644
index 0000000000..0a18ac7acc
--- /dev/null
+++ b/driver/charger/rt946x.h
@@ -0,0 +1,240 @@
+/* Copyright 2017 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.
+ *
+ * Richtek rt9466/rt9467 battery charger driver.
+ */
+
+#ifndef __CROS_EC_RT946X_H
+#define __CROS_EC_RT946X_H
+
+/* Charger parameters */
+#define CHARGER_NAME	RT946X_CHARGER_NAME
+#define CHARGE_V_MAX	4710
+#define CHARGE_V_MIN	3900
+#define CHARGE_V_STEP	10
+#define CHARGE_I_MAX	5000
+#define CHARGE_I_MIN	100
+#define CHARGE_I_OFF	0
+#define CHARGE_I_STEP	100
+#define INPUT_I_MAX	3250
+#define INPUT_I_MIN	100
+#define INPUT_I_STEP	50
+
+/* Registers */
+#define RT946X_REG_CORECTRL0		0x00
+#define RT946X_REG_CHGCTRL1		0x01
+#define RT946X_REG_CHGCTRL2		0x02
+#define RT946X_REG_CHGCTRL3		0x03
+#define RT946X_REG_CHGCTRL4		0x04
+#define RT946X_REG_CHGCTRL5		0x05
+#define RT946X_REG_CHGCTRL6		0x06
+#define RT946X_REG_CHGCTRL7		0x07
+#define RT946X_REG_CHGCTRL8		0x08
+#define RT946X_REG_CHGCTRL9		0x09
+#define RT946X_REG_CHGCTRL10		0x0A
+#define RT946X_REG_CHGCTRL11		0x0B
+#define RT946X_REG_CHGCTRL12		0x0C
+#define RT946X_REG_CHGCTRL13		0x0D
+#define RT946X_REG_CHGCTRL14		0x0E
+#define RT946X_REG_CHGCTRL15		0x0F
+#define RT946X_REG_CHGCTRL16		0x10
+#define RT946X_REG_CHGADC		0x11
+
+#ifdef CONFIG_CHARGER_RT9467
+#define RT946X_REG_DPDM1		0x12
+#define RT946X_REG_DPDM2		0x13
+#define RT946X_REG_DPDM3		0x14
+#endif
+
+#define RT946X_REG_CHGCTRL19		0x18
+#define RT946X_REG_CHGCTRL17		0x19
+#define RT946X_REG_CHGCTRL18		0x1A
+#define RT946X_REG_CHGHIDDENCTRL2	0x21
+#define RT946X_REG_CHGHIDDENCTRL4	0x23
+#define RT946X_REG_CHGHIDDENCTRL6	0x25
+#define RT946X_REG_CHGHIDDENCTRL7	0x26
+#define RT946X_REG_CHGHIDDENCTRL8	0x27
+#define RT946X_REG_CHGHIDDENCTRL9	0x28
+#define RT946X_REG_CHGHIDDENCTRL15	0x2E
+#define RT946X_REG_DEVICEID		0x40
+#define RT946X_REG_CHGSTAT		0x42
+#define RT946X_REG_CHGNTC		0x43
+#define RT946X_REG_ADCDATAH		0x44
+#define RT946X_REG_ADCDATAL		0x45
+#define RT946X_REG_CHGSTATC		0x50
+#define RT946X_REG_CHGFAULT		0x51
+#define RT946X_REG_TSSTATC		0x52
+#define RT946X_REG_CHGIRQ1		0x53
+#define RT946X_REG_CHGIRQ2		0x54
+#define RT946X_REG_CHGIRQ3		0x55
+
+#ifdef CONFIG_CHARGER_RT9467
+#define RT946X_REG_DPDMIRQ		0x56
+#endif
+
+#define RT946X_REG_CHGSTATCCTRL		0x60
+#define RT946X_REG_CHGFAULTCTRL		0x61
+#define RT946X_REG_TSSTATCCTRL		0x62
+#define RT946X_REG_CHGIRQ1CTRL		0x63
+#define RT946X_REG_CHGIRQ2CTRL		0x64
+#define RT946X_REG_CHGIRQ3CTRL		0x65
+
+#ifdef CONFIG_CHARGER_RT9467
+#define RT946X_REG_DPDMIRQCTRL		0x66
+#endif
+
+/* EOC current */
+#define RT946X_IEOC_MIN		100
+#define RT946X_IEOC_MAX		850
+#define RT946X_IEOC_STEP	50
+
+/* Minimum Input Voltage Regulator */
+#define RT946X_MIVR_MIN		3900
+#define RT946X_MIVR_MAX		13400
+#define RT946X_MIVR_STEP	100
+
+/* Boost voltage */
+#define RT946X_BOOST_VOLTAGE_MIN	4425
+#define RT946X_BOOST_VOLTAGE_MAX	5825
+#define RT946X_BOOST_VOLTAGE_STEP	25
+
+/* IR compensation resistor */
+#define RT946X_IRCMP_RES_MIN	0
+#define RT946X_IRCMP_RES_MAX	175
+#define RT946X_IRCMP_RES_STEP	25
+
+/* IR compensation voltage clamp */
+#define RT946X_IRCMP_VCLAMP_MIN		0
+#define RT946X_IRCMP_VCLAMP_MAX		224
+#define RT946X_IRCMP_VCLAMP_STEP	32
+
+/* AICLVTH */
+#define RT946X_AICLVTH_MIN	4100
+#define RT946X_AICLVTH_MAX	4800
+#define RT946X_AICLVTH_STEP	100
+
+/* NTC */
+#define RT946X_BATTEMP_NORMAL	0x00
+#define RT946X_BATTEMP_WARM	0x02
+#define RT946X_BATTEMP_COOL	0x03
+#define RT946X_BATTEMP_COLD	0x05
+#define RT946X_BATTEMP_HOT	0x06
+
+/* ========== CORECTRL0 0x00 ============ */
+#define RT946X_SHIFT_RST	7
+
+#define RT946X_MASK_RST		(1 << RT946X_SHIFT_RST)
+
+/* ========== CHGCTRL1 0x01 ============ */
+#define RT946X_SHIFT_OPA_MODE   0
+#define RT946X_SHIFT_HZ_EN      2
+
+#define RT946X_MASK_OPA_MODE	(1 << RT946X_SHIFT_OPA_MODE)
+#define RT946X_MASK_HZ_EN	(1 << RT946X_SHIFT_HZ_EN)
+
+/* ========== CHGCTRL2 0x02 ============ */
+#define RT946X_SHIFT_ILMTSEL	2
+#define RT946X_SHIFT_CHG_EN	0
+
+#define RT946X_MASK_ILMTSEL	0x0C
+#define RT946X_MASK_CHG_EN	(1 << RT946X_SHIFT_CHG_EN)
+
+/* ========== CHGCTRL3 0x03 ============ */
+#define RT946X_SHIFT_AICR	2
+#define RT946X_SHIFT_ILIMEN	0
+
+#define RT946X_MASK_AICR	0xFC
+#define RT946X_MASK_ILIMEN	(1 << RT946X_SHIFT_ILIMEN)
+
+/* ========== CHGCTRL4 0x04 ============ */
+#define RT946X_SHIFT_CV	1
+
+#define RT946X_MASK_CV	0xFE
+
+/* ========== CHGCTRL5 0x05 ============ */
+#define RT946X_SHIFT_BOOST_VOLTAGE	2
+
+#define RT946X_MASK_BOOST_VOLTAGE	0xFC
+
+/* ========== CHGCTRL6 0x06 ============ */
+#define RT946X_SHIFT_MIVR	1
+
+#define RT946X_MASK_MIVR	0xFE
+
+/* ========== CHGCTRL7 0x07 ============ */
+#define RT946X_SHIFT_ICHG	2
+
+#define RT946X_MASK_ICHG	0xFC
+
+/* ========== CHGCTRL9 0x09 ============ */
+#define RT946X_SHIFT_IEOC	4
+
+#define RT946X_MASK_IEOC	0xF0
+
+/* ========== CHGCTRL10 0x0A ============ */
+#define RT946X_SHIFT_BOOST_CURRENT	0
+
+#define RT946X_MASK_BOOST_CURRENT	0x07
+
+/* ========== CHGCTRL13 0x0D ============ */
+#define RT946X_SHIFT_WDT_EN	7
+
+#define RT946X_MASK_WDT_EN	(1 << RT946X_SHIFT_WDT_EN)
+
+/* ========== CHGCTRL14 0x0E ============ */
+#define RT946X_SHIFT_AICLMEAS	7
+#define RT946X_SHIFT_AICLVTH	0
+
+#define RT946X_MASK_AICLMEAS	(1 << RT946X_SHIFT_AICLMEAS)
+#define RT946X_MASK_AICLVTH	0x07
+
+/* ========== CHGDPDM1 0x12 ============ */
+#define RT946X_MASK_USBCHGEN	(1 << 7)
+
+/* ========== CHGCTRL18 0x1A ============ */
+#define RT946X_SHIFT_IRCMP_RES		3
+#define RT946X_SHIFT_IRCMP_VCLAMP	0
+
+#define RT946X_MASK_IRCMP_RES		0x38
+#define RT946X_MASK_IRCMP_VCLAMP	0x07
+
+/* ========== DEVICE_ID 0x40 ============ */
+#define RT946X_MASK_VENDOR_ID	0xF0
+#define RT946X_MASK_CHIP_REV	0x0F
+
+/* ========== CHGSTAT 0x42 ============ */
+#define RT946X_SHIFT_CHG_STAT	6
+
+#define RT946X_MASK_CHG_STAT	0xC0
+
+/* ========== CHGNTC 0x43 ============ */
+#define RT946X_SHIFT_BATNTC_FAULT	4
+
+#define RT946X_MASK_BATNTC_FAULT	0x70
+
+/* ========== CHGFAULT 0x51 ============ */
+#define RT946X_SHIFT_CHG_VSYSUV	4
+#define RT946X_SHIFT_CHG_VSYSOV	5
+#define RT946X_SHIFT_CHG_VBATOV	6
+#define RT946X_SHIFT_CHG_VBUSOV	7
+
+#define RT946X_MASK_CHG_VSYSUV	(1 << RT946X_SHIFT_CHG_VSYSUV)
+#define RT946X_MASK_CHG_VSYSOV	(1 << RT946X_SHIFT_CHG_VSYSOV)
+#define RT946X_MASK_CHG_VBATOV	(1 << RT946X_SHIFT_CHG_VBATOV)
+#define RT946X_MASK_CHG_VBUSOV	(1 << RT946X_SHIFT_CHG_VBUSOV)
+
+/* ========== Variant-specific configuration ============ */
+#if defined(CONFIG_CHARGER_RT9466)
+	#define RT946X_CHARGER_NAME	"rt9466"
+	#define RT946X_VENDOR_ID	0x80
+	#define RT946X_CHIP_REV		0x05
+	#define RT946X_ADDR		(0x53 << 1)
+#elif defined(CONFIG_CHARGER_RT9467)
+	#define RT946X_CHARGER_NAME	"rt9467"
+	#define RT946X_VENDOR_ID	0x90
+	#define RT946X_CHIP_REV		0x05
+	#define RT946X_ADDR		(0x5B << 1)
+#endif
+
+#endif /* __CROS_EC_RT946X_H */
diff --git a/include/config.h b/include/config.h
index 9421cb4a81..6f8cf1bf77 100644
--- a/include/config.h
+++ b/include/config.h
@@ -433,6 +433,8 @@
 #undef CONFIG_CHARGER_BQ25895
 #undef CONFIG_CHARGER_ISL9237
 #undef CONFIG_CHARGER_ISL9238
+#undef CONFIG_CHARGER_RT9466
+#undef CONFIG_CHARGER_RT9467
 
 /*
  * Enable the CHG_EN at initialization to turn-on the BGATE which allows voltage