charger: isl923x: Add support for ISL9238

ISL9237 and ISL9238 are almost identical, with few register changes,
let's make the driver generic, to support both chargers.

BRANCH=none
BUG=chrome-os-partner:61166
TEST=make buildall -j

Change-Id: I029894dd62ab7e45897d877289707ee8c1ff1d09
Reviewed-on: https://chromium-review.googlesource.com/422197
Commit-Ready: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

5 files changed, 330 insertions, 300 deletions

diff --git a/driver/build.mk b/driver/build.mk
index aab87ee035..32da5f9686 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -47,7 +47,8 @@ driver-$(CONFIG_CHARGER_BQ24773)+=charger/bq24773.o
 driver-$(CONFIG_CHARGER_BQ25890)+=charger/bq2589x.o
 driver-$(CONFIG_CHARGER_BQ25892)+=charger/bq2589x.o
 driver-$(CONFIG_CHARGER_BQ25895)+=charger/bq2589x.o
-driver-$(CONFIG_CHARGER_ISL9237)+=charger/isl9237.o
+driver-$(CONFIG_CHARGER_ISL9237)+=charger/isl923x.o
+driver-$(CONFIG_CHARGER_ISL9238)+=charger/isl923x.o
 
 # I/O expander
 driver-$(CONFIG_IO_EXPANDER_PCA9534)+=ioexpander_pca9534.o
diff --git a/driver/charger/isl9237.h b/driver/charger/isl9237.h
deleted file mode 100644
index 27a3bab377..0000000000
--- a/driver/charger/isl9237.h
+++ /dev/null
@@ -1,248 +0,0 @@
-/* Copyright 2015 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.
- *
- * Intersil ISL-9237 battery charger driver.
- */
-
-#ifndef __CROS_EC_ISL9237_H
-#define __CROS_EC_ISL9237_H
-
-#define ISL9237_ADDR 0x12 /* 7bit address 0001001 */
-
-/* Registers */
-#define ISL9237_REG_CHG_CURRENT      0x14
-#define ISL9237_REG_ADAPTER_CURRENT1 0x3f
-#define ISL9237_REG_ADAPTER_CURRENT2 0x3b
-#define ISL9237_REG_SYS_VOLTAGE_MAX  0x15
-#define ISL9237_REG_SYS_VOLTAGE_MIN  0x3e
-#define ISL9237_REG_PROCHOT_AC       0x47
-#define ISL9237_REG_PROCHOT_DC       0x48
-#define ISL9237_REG_T1_T2            0x38
-#define ISL9237_REG_CONTROL1         0x3c
-#define ISL9237_REG_CONTROL2         0x3d
-#define ISL9237_REG_INFO             0x3a
-#define ISL9237_REG_OTG_VOLTAGE      0x49
-#define ISL9237_REG_OTG_CURRENT      0x4a
-#define ISL9237_REG_MANUFACTURER_ID  0xfe
-#define ISL9237_REG_DEVICE_ID        0xff
-#define ISL9237_REG_CONTROL0         0x39
-
-/* Sense resistor default values in mOhm */
-#define ISL9237_DEFAULT_SENSE_RESISTOR_AC 20
-#define ISL9237_DEFAULT_SENSE_RESISTOR 10
-
-/* Maximum charging current register value */
-#define ISL9237_CURRENT_REG_MAX 0x17c0 /* bit<12:2> 10111110000 */
-
-/* 2-level adpater current limit duration T1 & T2 in micro seconds */
-#define ISL9237_T1_10000 0x00
-#define ISL9237_T1_20000 0x01
-#define ISL9237_T1_15000 0x02
-#define ISL9237_T1_5000  0x03
-#define ISL9237_T1_1000  0x04
-#define ISL9237_T1_500   0x05
-#define ISL9237_T1_100   0x06
-#define ISL9237_T1_0     0x07
-#define ISL9237_T2_10    (0x00 << 8)
-#define ISL9237_T2_100   (0x01 << 8)
-#define ISL9237_T2_500   (0x02 << 8)
-#define ISL9237_T2_1000  (0x03 << 8)
-#define ISL9237_T2_300   (0x04 << 8)
-#define ISL9237_T2_750   (0x05 << 8)
-#define ISL9237_T2_2000  (0x06 << 8)
-#define ISL9237_T2_10000 (0x07 << 8)
-
-#define ISL9237_SYS_VOLTAGE_REG_MAX 13824
-#define ISL9237_SYS_VOLTAGE_REG_MIN 2048
-
-/* PROCHOT# debounce time and duration time in micro seconds */
-#define ISL9237_PROCHOT_DURATION_10000  (0 << 6)
-#define ISL9237_PROCHOT_DURATION_20000  (1 << 6)
-#define ISL9237_PROCHOT_DURATION_15000  (2 << 6)
-#define ISL9237_PROCHOT_DURATION_5000   (3 << 6)
-#define ISL9237_PROCHOT_DURATION_1000   (4 << 6)
-#define ISL9237_PROCHOT_DURATION_500    (5 << 6)
-#define ISL9237_PROCHOT_DURATION_100000 (6 << 6)
-#define ISL9237_PROCHOT_DURATION_0      (7 << 6)
-#define ISL9237_PROCHOT_DURATION_MASK   (7 << 6)
-
-#define ISL9237_PROCHOT_DEBOUNCE_10   (0 << 9)
-#define ISL9237_PROCHOT_DEBOUNCE_100  (1 << 9)
-#define ISL9237_PROCHOT_DEBOUNCE_500  (2 << 9)
-#define ISL9237_PROCHOT_DEBOUNCE_1000 (3 << 9)
-#define ISL9237_PROCHOT_DEBOUNCE_MASK (3 << 9)
-
-/* Maximum PROCHOT register value */
-#define ISL9237_PROCHOT_AC_REG_MAX 6400
-#define ISL9237_PROCHOT_DC_REG_MAX 12800
-
-/* Control0: adapter voltage regulation reference */
-#define ISL9237_C0_VREG_REF_3900 0
-#define ISL9237_C0_VREG_REF_4200 1
-#define ISL9237_C0_VREG_REF_4500 2
-#define ISL9237_C0_VREG_REF_4800 3
-#define ISL9237_C0_VREG_REF_MASK 0x03
-
-/* Control0: disable adapter voltaqe regulation */
-#define ISL9237_C0_DISABLE_VREG (1 << 2)
-
-/* Control0: battery DCHOT reference for RS2 == 20mOhm */
-#define ISL9237_C0_DCHOT_6A   (0 << 3)
-#define ISL9237_C0_DCHOT_5A   (1 << 3)
-#define ISL9237_C0_DCHOT_4A   (2 << 3)
-#define ISL9237_C0_DCHOT_3A   (3 << 3)
-#define ISL9237_C0_DCHOT_MASK (3 << 3)
-
-/* Control1: general purpose comparator debounce time in micro second */
-#define ISL9237_C1_GP_DEBOUNCE_2       (0 << 14)
-#define ISL9237_C1_GP_DEBOUNCE_12      (1 << 14)
-#define ISL9237_C1_GP_DEBOUNCE_2000    (2 << 14)
-#define ISL9237_C1_GP_DEBOUNCE_5000000 (3 << 14)
-#define ISL9237_C1_GP_DEBOUNCE_MASK    (3 << 14)
-
-/* Control1: learn mode */
-#define ISL9237_C1_LEARN_MODE_AUTOEXIT (1 << 13)
-#define ISL9237_C1_LEARN_MODE_ENABLE   (1 << 12)
-
-/* Control1: OTG enable */
-#define ISL9237_C1_OTG (1 << 11)
-
-/* Control1: audio filter */
-#define ISL9237_C1_AUDIO_FILTER (1 << 10)
-
-/* Control1: switch frequency */
-#define ISL9237_C1_SWITCH_FREQ_PROG (0 << 7) /* 1000kHz or PROG */
-#define ISL9237_C1_SWITCH_FREQ_913K (1 << 7)
-#define ISL9237_C1_SWITCH_FREQ_839K (2 << 7)
-#define ISL9237_C1_SWITCH_FREQ_777K (3 << 7)
-#define ISL9237_C1_SWITCH_FREQ_723K (4 << 7)
-#define ISL9237_C1_SWITCH_FREQ_676K (5 << 7)
-#define ISL9237_C1_SWITCH_FREQ_635K (6 << 7)
-#define ISL9237_C1_SWITCH_FREQ_599K (7 << 7)
-#define ISL9237_C1_SWITCH_FREQ_MASK (7 << 7)
-
-/* Control1: turbo mode */
-#define ISL9237_C1_TURBO_MODE (1 << 6)
-
-/* Control1: AMON & BMON */
-#define ISL9237_C1_DISABLE_MON (1 << 5)
-#define ISL9237_C1_SELECT_BMON (1 << 4)
-
-/* Control1: PSYS, VSYS, VSYSLO */
-#define ISL9237_C1_ENABLE_PSYS (1 << 3)
-#define ISL9237_C1_ENABLE_VSYS (1 << 2)
-#define ISL9237_C1_VSYSLO_REF_6000 0
-#define ISL9237_C1_VSYSLO_REF_6300 1
-#define ISL9237_C1_VSYSLO_REF_6600 2
-#define ISL9237_C1_VSYSLO_REF_6900 3
-#define ISL9237_C1_VSYSLO_REF_MASK 3
-
-/* Control2: trickle charging current in mA */
-#define ISL9237_C2_TRICKLE_256  (0 << 14)
-#define ISL9237_C2_TRICKLE_128  (1 << 14)
-#define ISL9237_C2_TRICKLE_64   (2 << 14)
-#define ISL9237_C2_TRICKLE_512  (3 << 14)
-#define ISL9237_C2_TRICKLE_MASK (3 << 14)
-
-/* Control2: OTGEN debounce time in ms */
-#define ISL9237_C2_OTG_DEBOUNCE_1300 (0 << 13)
-#define ISL9237_C2_OTG_DEBOUNCE_150  (1 << 13)
-#define ISL9237_C2_OTG_DEBOUNCE_MASK (1 << 13)
-
-/* Control2: 2-level adapter over current */
-#define ISL9237_C2_2LVL_OVERCURRENT (1 << 12)
-
-/* Control2: adapter insertion debounce time in ms */
-#define ISL9237_C2_ADAPTER_DEBOUNCE_1300 (0 << 11)
-#define ISL9237_C2_ADAPTER_DEBOUNCE_150  (1 << 11)
-#define ISL9237_C2_ADAPTER_DEBOUNCE_MASK (1 << 11)
-
-/* Control2: PROCHOT debounce time in uS */
-#define ISL9237_C2_PROCHOT_DEBOUNCE_10   (0 << 9)
-#define ISL9237_C2_PROCHOT_DEBOUNCE_100  (1 << 9)
-#define ISL9237_C2_PROCHOT_DEBOUNCE_500  (2 << 9)
-#define ISL9237_C2_PROCHOT_DEBOUNCE_1000 (3 << 9)
-#define ISL9237_C2_PROCHOT_DEBOUNCE_MASK (3 << 9)
-
-/* Control2: min PROCHOT duration in uS */
-#define ISL9237_C2_PROCHOT_DURATION_10000 (0 << 6)
-#define ISL9237_C2_PROCHOT_DURATION_20000 (1 << 6)
-#define ISL9237_C2_PROCHOT_DURATION_15000 (2 << 6)
-#define ISL9237_C2_PROCHOT_DURATION_5000  (3 << 6)
-#define ISL9237_C2_PROCHOT_DURATION_1000  (4 << 6)
-#define ISL9237_C2_PROCHOT_DURATION_500   (5 << 6)
-#define ISL9237_C2_PROCHOT_DURATION_100   (6 << 6)
-#define ISL9237_C2_PROCHOT_DURATION_0     (7 << 6)
-#define ISL9237_C2_PROCHOT_DURATION_MASK  (7 << 6)
-
-/* Control2: turn off ASGATE in OTG mode */
-#define ISL9237_C2_ASGATE_OFF (1 << 5)
-
-/* Control2: CMIN, general purpose comparator reference in mV */
-#define ISL9237_C2_CMIN_2000 (0 << 4)
-#define ISL9237_C2_CMIN_1200 (1 << 4)
-
-/* Control2: general purpose comparator enable */
-#define ISL9237_C2_COMPARATOR (1 << 3)
-
-/* Control2: invert CMOUT, general purpose comparator output, polarity */
-#define ISL9237_C2_INVERT_CMOUT (1 << 2)
-
-/* Control2: disable WOC, way over current */
-#define ISL9237_C2_WOC_OFF (1 << 1)
-
-/* Control2: PSYS gain in uA/W */
-#define ISL9237_C2_PSYS_GAIN (1 << 0)
-
-/* OTG voltage limit in mV, current limit in mA */
-#define ISL9237_OTG_VOLTAGE_MIN 4864
-#define ISL9237_OTG_VOLTAGE_MAX 5376
-#define ISL9237_OTG_CURRENT_MAX 4096
-
-/* Info register fields */
-#define ISL9237_INFO_PROG_RESISTOR_MASK 0xf
-#define ISL9237_INFO_TRICKLE_ACTIVE_MASK (1 << 4)
-#define ISL9237_INFO_PSTATE_SHIFT 5
-#define ISL9237_INFO_PSTATE_MASK 3
-
-enum isl9237_power_stage {
-	BUCK_MODE,
-	BOOST_MODE,
-	BUCK_BOOST_MODE,
-	REVERSE_BUCK_MODE
-};
-
-#define ISL9237_INFO_FSM_STATE_SHIFT 7
-#define ISL9237_INFO_FSM_STATE_MASK 7
-
-enum isl9237_fsm_state {
-	FSM_OFF,
-	FSM_BAT,
-	FSM_ADPT,
-	FSM_ACOK,
-	FSM_VSYS,
-	FSM_CHRG,
-	FSM_ENTOG,
-	FSM_OTG
-};
-
-#define ISL9237_INFO_VSYSLO (1 << 10)
-#define ISL9237_INFO_DCHOT (1 << 11)
-#define ISL9237_INFO_ACHOT (1 << 12)
-
-
-#define CHARGER_NAME  "isl9237"
-#define CHARGE_V_MAX  ISL9237_SYS_VOLTAGE_REG_MAX
-#define CHARGE_V_MIN  ISL9237_SYS_VOLTAGE_REG_MIN
-#define CHARGE_V_STEP 8
-#define CHARGE_I_MAX  ISL9237_CURRENT_REG_MAX
-#define CHARGE_I_MIN  4
-#define CHARGE_I_OFF  0
-#define CHARGE_I_STEP 4
-#define INPUT_I_MAX   ISL9237_CURRENT_REG_MAX
-#define INPUT_I_MIN   4
-#define INPUT_I_STEP  4
-
-#define I2C_ADDR_CHARGER ISL9237_ADDR
-#endif /* __CROS_EC_ISL9237_H */
diff --git a/driver/charger/isl9237.c b/driver/charger/isl923x.c
index 3be623ff00..81a9dd3582 100644
--- a/driver/charger/isl9237.c
+++ b/driver/charger/isl923x.c
@@ -2,7 +2,7 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
- * Intersil ISL9237 battery charger driver.
+ * Intersil ISL-9237/8 battery charger driver.
  */
 
 #include "adc.h"
@@ -13,7 +13,7 @@
 #include "common.h"
 #include "hooks.h"
 #include "i2c.h"
-#include "isl9237.h"
+#include "isl923x.h"
 #include "timer.h"
 #include "util.h"
 
@@ -62,12 +62,12 @@ static inline int raw_write16(int offset, int value)
 
 static int isl9237_set_current(uint16_t current)
 {
-	return raw_write16(ISL9237_REG_CHG_CURRENT, CURRENT_TO_REG(current));
+	return raw_write16(ISL923X_REG_CHG_CURRENT, CURRENT_TO_REG(current));
 }
 
 static int isl9237_set_voltage(uint16_t voltage)
 {
-	return raw_write16(ISL9237_REG_SYS_VOLTAGE_MAX, voltage);
+	return raw_write16(ISL923X_REG_SYS_VOLTAGE_MAX, voltage);
 }
 
 /* chip specific interfaces */
@@ -77,11 +77,11 @@ int charger_set_input_current(int input_current)
 	int rv;
 	uint16_t reg = AC_CURRENT_TO_REG(input_current);
 
-	rv = raw_write16(ISL9237_REG_ADAPTER_CURRENT1, reg);
+	rv = raw_write16(ISL923X_REG_ADAPTER_CURRENT1, reg);
 	if (rv)
 		return rv;
 
-	return raw_write16(ISL9237_REG_ADAPTER_CURRENT2, reg);
+	return raw_write16(ISL923X_REG_ADAPTER_CURRENT2, reg);
 }
 
 int charger_get_input_current(int *input_current)
@@ -89,7 +89,7 @@ int charger_get_input_current(int *input_current)
 	int rv;
 	int reg;
 
-	rv = raw_read16(ISL9237_REG_ADAPTER_CURRENT1, &reg);
+	rv = raw_read16(ISL923X_REG_ADAPTER_CURRENT1, &reg);
 	if (rv)
 		return rv;
 
@@ -102,7 +102,7 @@ int charger_manufacturer_id(int *id)
 	int rv;
 	int reg;
 
-	rv = raw_read16(ISL9237_REG_MANUFACTURER_ID, &reg);
+	rv = raw_read16(ISL923X_REG_MANUFACTURER_ID, &reg);
 	if (rv)
 		return rv;
 
@@ -115,7 +115,7 @@ int charger_device_id(int *id)
 	int rv;
 	int reg;
 
-	rv = raw_read16(ISL9237_REG_DEVICE_ID, &reg);
+	rv = raw_read16(ISL923X_REG_DEVICE_ID, &reg);
 	if (rv)
 		return rv;
 
@@ -129,12 +129,12 @@ int charger_get_option(int *option)
 	uint32_t controls;
 	int reg;
 
-	rv = raw_read8(ISL9237_REG_CONTROL0, &reg);
+	rv = raw_read8(ISL923X_REG_CONTROL0, &reg);
 	if (rv)
 		return rv;
 
 	controls = reg;
-	rv = raw_read16(ISL9237_REG_CONTROL1, &reg);
+	rv = raw_read16(ISL923X_REG_CONTROL1, &reg);
 	if (rv)
 		return rv;
 
@@ -149,13 +149,13 @@ int charger_set_option(int option)
 	uint16_t reg;
 
 	reg = option & 0xffff;
-	rv = raw_write16(ISL9237_REG_CONTROL0, reg);
+	rv = raw_write16(ISL923X_REG_CONTROL0, reg);
 
 	if (rv)
 		return rv;
 
 	reg = (option >> 16) & 0xffff;
-	return raw_write16(ISL9237_REG_CONTROL1, reg);
+	return raw_write16(ISL923X_REG_CONTROL1, reg);
 }
 
 /* Charger interfaces */
@@ -183,7 +183,7 @@ int charger_set_mode(int mode)
 	if (!learn_mode)
 		rv = charger_discharge_on_ac(0);
 
-	/* ISL9237 does not support inhibit mode setting. */
+	/* ISL923X does not support inhibit mode setting. */
 	return rv;
 }
 
@@ -192,7 +192,7 @@ int charger_get_current(int *current)
 	int rv;
 	int reg;
 
-	rv = raw_read16(ISL9237_REG_CHG_CURRENT, &reg);
+	rv = raw_read16(ISL923X_REG_CHG_CURRENT, &reg);
 	if (rv)
 		return rv;
 
@@ -207,14 +207,14 @@ int charger_set_current(int current)
 
 int charger_get_voltage(int *voltage)
 {
-	return raw_read16(ISL9237_REG_SYS_VOLTAGE_MAX, voltage);
+	return raw_read16(ISL923X_REG_SYS_VOLTAGE_MAX, voltage);
 }
 
 int charger_set_voltage(int voltage)
 {
-	/* The ISL9237 will drop voltage to as low as requested. As the
+	/* The ISL923X will drop voltage to as low as requested. As the
 	 * charger state machine will pass in 0 voltage, protect the system
-	 * voltage by capping to the minimum. The reason is that the ISL9237
+	 * voltage by capping to the minimum. The reason is that the ISL923X
 	 * only can regulate the system voltage which will kill the board's
 	 * power if below 0. */
 	if (voltage == 0) {
@@ -232,7 +232,7 @@ int charger_post_init(void)
 #ifdef CONFIG_TRICKLE_CHARGING
 	const struct battery_info *bi = battery_get_info();
 
-	rv = raw_write16(ISL9237_REG_SYS_VOLTAGE_MIN, bi->voltage_min);
+	rv = raw_write16(ISL923X_REG_SYS_VOLTAGE_MIN, bi->voltage_min);
 	if (rv)
 		return rv;
 #endif
@@ -241,31 +241,42 @@ int charger_post_init(void)
 	 * [10:9]: Prochot# Debounce time
 	 *         11b: 1ms
 	 */
-	rv = raw_read16(ISL9237_REG_CONTROL2, &reg);
+	rv = raw_read16(ISL923X_REG_CONTROL2, &reg);
 	if (rv)
 		return rv;
 
-	rv = raw_write16(ISL9237_REG_CONTROL2,
+	rv = raw_write16(ISL923X_REG_CONTROL2,
 			reg |
-			ISL9237_C2_PROCHOT_DEBOUNCE_1000 |
-			ISL9237_C2_ADAPTER_DEBOUNCE_150);
+			ISL923X_C2_PROCHOT_DEBOUNCE_1000 |
+			ISL923X_C2_ADAPTER_DEBOUNCE_150);
 	if (rv)
 		return rv;
 
+#ifdef CONFIG_CHARGE_RAMP_HW
+#ifdef CONFIG_ISL9237
 	rv = charger_get_option(&reg);
 	if (rv)
 		return rv;
 
-#ifdef CONFIG_CHARGE_RAMP_HW
 	/* Set input voltage regulation reference voltage for charge ramp */
-	reg &= ~ISL9237_C0_VREG_REF_MASK;
-	reg |= ISL9237_C0_VREG_REF_4200;
+	reg &= ~ISL923X_C0_VREG_REF_MASK;
+	reg |= ISL923X_C0_VREG_REF_4200;
+
+	return charger_set_option(reg);
 #else
-	/* Disable voltage regulation loop to disable charge ramp */
-	reg |= ISL9237_C0_DISABLE_VREG;
+	/* ISL9238 default input voltage regulation is 4096 mV. */
+	return EC_SUCCESS;
 #endif
+#else
+	rv = charger_get_option(&reg);
+	if (rv)
+		return rv;
+
+	/* Disable voltage regulation loop to disable charge ramp */
+	reg |= ISL923X_C0_DISABLE_VREG;
 
 	return charger_set_option(reg);
+#endif
 }
 
 int charger_discharge_on_ac(int enable)
@@ -273,17 +284,17 @@ int charger_discharge_on_ac(int enable)
 	int rv;
 	int control1;
 
-	rv = raw_read16(ISL9237_REG_CONTROL1, &control1);
+	rv = raw_read16(ISL923X_REG_CONTROL1, &control1);
 	if (rv)
 		return rv;
 
-	control1 &= ~ISL9237_C1_LEARN_MODE_AUTOEXIT;
+	control1 &= ~ISL923X_C1_LEARN_MODE_AUTOEXIT;
 	if (enable)
-		control1 |= ISL9237_C1_LEARN_MODE_ENABLE;
+		control1 |= ISL923X_C1_LEARN_MODE_ENABLE;
 	else
-		control1 &= ~ISL9237_C1_LEARN_MODE_ENABLE;
+		control1 &= ~ISL923X_C1_LEARN_MODE_ENABLE;
 
-	rv = raw_write16(ISL9237_REG_CONTROL1, control1);
+	rv = raw_write16(ISL923X_REG_CONTROL1, control1);
 
 	learn_mode = !rv && enable;
 	return rv;
@@ -303,9 +314,9 @@ int charger_set_hw_ramp(int enable)
 
 	/* HW ramp is controlled by input voltage regulation reference bits */
 	if (enable)
-		reg &= ~ISL9237_C0_DISABLE_VREG;
+		reg &= ~ISL923X_C0_DISABLE_VREG;
 	else
-		reg |= ISL9237_C0_DISABLE_VREG;
+		reg |= ISL923X_C0_DISABLE_VREG;
 
 	return charger_set_option(reg);
 }
@@ -348,9 +359,9 @@ static void charger_enable_psys(void)
 	/*
 	 * enable system power monitor PSYS function
 	 */
-	if (!raw_read16(ISL9237_REG_CONTROL1, &val)) {
-		val |= ISL9237_C1_ENABLE_PSYS;
-		raw_write16(ISL9237_REG_CONTROL1, val);
+	if (!raw_read16(ISL923X_REG_CONTROL1, &val)) {
+		val |= ISL923X_C1_ENABLE_PSYS;
+		raw_write16(ISL923X_REG_CONTROL1, val);
 	}
 }
 DECLARE_HOOK(HOOK_CHIPSET_STARTUP, charger_enable_psys, HOOK_PRIO_DEFAULT);
@@ -362,14 +373,15 @@ static void charger_disable_psys(void)
 	/*
 	 * disable system power monitor PSYS function
 	 */
-	if (!raw_read16(ISL9237_REG_CONTROL1, &val)) {
-		val &= ~ISL9237_C1_ENABLE_PSYS;
-		raw_write16(ISL9237_REG_CONTROL1, val);
+	if (!raw_read16(ISL923X_REG_CONTROL1, &val)) {
+		val &= ~ISL923X_C1_ENABLE_PSYS;
+		raw_write16(ISL923X_REG_CONTROL1, val);
 	}
 }
 DECLARE_HOOK(HOOK_CHIPSET_SHUTDOWN, charger_disable_psys, HOOK_PRIO_DEFAULT);
 
 #ifdef CONFIG_CMD_CHARGER_PSYS
+/* TODO(crosbug.com/p/61166): This dead code is ISL9237-specific. */
 #define PSYS_ADC_READ_COUNT 100
 static int charger_get_system_power(void)
 {
@@ -378,7 +390,7 @@ static int charger_get_system_power(void)
 	int ret;
 	int val;
 
-	ret = raw_read16(ISL9237_REG_CONTROL2, &val);
+	ret = raw_read16(ISL923X_REG_CONTROL2, &val);
 	if (ret)
 		return ret;
 
@@ -397,11 +409,11 @@ static int charger_get_system_power(void)
 	 *
 	 * Do not divide the constants first to ensure precision is not lost.
 	 */
-	if (val & ISL9237_C2_PSYS_GAIN)
-		return ((adc * ISL9237_C2_PSYS_GAIN_0_36) /
+	if (val & ISL923X_C2_PSYS_GAIN)
+		return ((adc * ISL923X_C2_PSYS_GAIN_0_36) /
 				PSYS_ADC_READ_COUNT);
 	else
-		return ((adc * ISL9237_C2_PSYS_GAIN_1_44) /
+		return ((adc * ISL923X_C2_PSYS_GAIN_1_44) /
 				PSYS_ADC_READ_COUNT);
 }
 
@@ -425,17 +437,17 @@ static int console_command_amon_bmon(int argc, char **argv)
 	int adc, curr, val, ret;
 
 	ret = i2c_read16(I2C_PORT_CHARGER, I2C_ADDR_CHARGER,
-			 ISL9237_REG_CONTROL1, &val);
+			 ISL923X_REG_CONTROL1, &val);
 	if (ret)
 		return ret;
 
 	/* Enable monitor */
-	val &= ~ISL9237_C1_DISABLE_MON;
+	val &= ~ISL923X_C1_DISABLE_MON;
 	if (argc == 1 || (argc >= 2 && argv[1][0] == 'a')) {
 		/* Switch to AMON */
-		val &= ~ISL9237_C1_SELECT_BMON;
+		val &= ~ISL923X_C1_SELECT_BMON;
 		ret = i2c_write16(I2C_PORT_CHARGER, I2C_ADDR_CHARGER,
-				  ISL9237_REG_CONTROL1, val);
+				  ISL923X_REG_CONTROL1, val);
 		if (ret)
 			return ret;
 
@@ -446,9 +458,9 @@ static int console_command_amon_bmon(int argc, char **argv)
 
 	if (argc == 1 || (argc >= 2 && argv[1][0] == 'b')) {
 		/* Switch to BMON */
-		val |= ISL9237_C1_SELECT_BMON;
+		val |= ISL923X_C1_SELECT_BMON;
 		ret = i2c_write16(I2C_PORT_CHARGER, I2C_ADDR_CHARGER,
-				  ISL9237_REG_CONTROL1, val);
+				  ISL923X_REG_CONTROL1, val);
 		if (ret)
 			return ret;
 
diff --git a/driver/charger/isl923x.h b/driver/charger/isl923x.h
new file mode 100644
index 0000000000..ba018e766c
--- /dev/null
+++ b/driver/charger/isl923x.h
@@ -0,0 +1,264 @@
+/* Copyright 2015 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.
+ *
+ * Intersil ISL-9237/8 battery charger driver.
+ */
+
+#ifndef __CROS_EC_ISL923X_H
+#define __CROS_EC_ISL923X_H
+
+#define ISL923X_ADDR 0x12 /* 7bit address 0001001 */
+
+/* Registers */
+#define ISL923X_REG_CHG_CURRENT      0x14
+#define ISL923X_REG_ADAPTER_CURRENT1 0x3f
+#define ISL923X_REG_ADAPTER_CURRENT2 0x3b
+#define ISL923X_REG_SYS_VOLTAGE_MAX  0x15
+#define ISL923X_REG_SYS_VOLTAGE_MIN  0x3e
+#define ISL923X_REG_PROCHOT_AC       0x47
+#define ISL923X_REG_PROCHOT_DC       0x48
+#define ISL923X_REG_T1_T2            0x38
+#define ISL923X_REG_CONTROL0         0x39
+#define ISL923X_REG_CONTROL1         0x3c
+#define ISL923X_REG_CONTROL2         0x3d
+#define ISL9238_REG_CONTROL3         0x4c
+#define ISL9238_REG_CONTROL4         0x4e
+#define ISL923X_REG_INFO             0x3a
+#define ISL9238_REG_INFO2            0x4d
+#define ISL923X_REG_OTG_VOLTAGE      0x49
+#define ISL923X_REG_OTG_CURRENT      0x4a
+#define ISL9238_REG_INPUT_VOLTAGE    0x4b
+#define ISL923X_REG_MANUFACTURER_ID  0xfe
+#define ISL923X_REG_DEVICE_ID        0xff
+
+/* Sense resistor default values in mOhm */
+#define ISL923X_DEFAULT_SENSE_RESISTOR_AC 20
+#define ISL923X_DEFAULT_SENSE_RESISTOR 10
+
+/* Maximum charging current register value */
+#define ISL923X_CURRENT_REG_MAX 0x17c0 /* bit<12:2> 10111110000 */
+
+/* 2-level adpater current limit duration T1 & T2 in micro seconds */
+#define ISL923X_T1_10000 0x00
+#define ISL923X_T1_20000 0x01
+#define ISL923X_T1_15000 0x02
+#define ISL923X_T1_5000  0x03
+#define ISL923X_T1_1000  0x04
+#define ISL923X_T1_500   0x05
+#define ISL923X_T1_100   0x06
+#define ISL923X_T1_0     0x07
+#define ISL923X_T2_10    (0x00 << 8)
+#define ISL923X_T2_100   (0x01 << 8)
+#define ISL923X_T2_500   (0x02 << 8)
+#define ISL923X_T2_1000  (0x03 << 8)
+#define ISL923X_T2_300   (0x04 << 8)
+#define ISL923X_T2_750   (0x05 << 8)
+#define ISL923X_T2_2000  (0x06 << 8)
+#define ISL923X_T2_10000 (0x07 << 8)
+
+#define ISL9237_SYS_VOLTAGE_REG_MAX 13824
+#define ISL9238_SYS_VOLTAGE_REG_MAX 18304
+#define ISL923X_SYS_VOLTAGE_REG_MIN 2048
+
+/* PROCHOT# debounce time and duration time in micro seconds */
+#define ISL923X_PROCHOT_DURATION_10000  (0 << 6)
+#define ISL923X_PROCHOT_DURATION_20000  (1 << 6)
+#define ISL923X_PROCHOT_DURATION_15000  (2 << 6)
+#define ISL923X_PROCHOT_DURATION_5000   (3 << 6)
+#define ISL923X_PROCHOT_DURATION_1000   (4 << 6)
+#define ISL923X_PROCHOT_DURATION_500    (5 << 6)
+#define ISL923X_PROCHOT_DURATION_100000 (6 << 6)
+#define ISL923X_PROCHOT_DURATION_0      (7 << 6)
+#define ISL923X_PROCHOT_DURATION_MASK   (7 << 6)
+
+#define ISL923X_PROCHOT_DEBOUNCE_10   (0 << 9)
+#define ISL923X_PROCHOT_DEBOUNCE_100  (1 << 9)
+#define ISL923X_PROCHOT_DEBOUNCE_500  (2 << 9)
+#define ISL923X_PROCHOT_DEBOUNCE_1000 (3 << 9)
+#define ISL923X_PROCHOT_DEBOUNCE_MASK (3 << 9)
+
+/* Maximum PROCHOT register value */
+#define ISL923X_PROCHOT_AC_REG_MAX 6400
+#define ISL923X_PROCHOT_DC_REG_MAX 12800
+
+/* Control0: adapter voltage regulation reference */
+#define ISL9237_C0_VREG_REF_3900 0
+#define ISL9237_C0_VREG_REF_4200 1
+#define ISL9237_C0_VREG_REF_4500 2
+#define ISL9237_C0_VREG_REF_4800 3
+#define ISL9237_C0_VREG_REF_MASK 0x03
+
+/* Control0: disable adapter voltaqe regulation */
+#define ISL923X_C0_DISABLE_VREG (1 << 2)
+
+/* Control0: battery DCHOT reference for RS2 == 20mOhm */
+#define ISL923X_C0_DCHOT_6A   (0 << 3)
+#define ISL923X_C0_DCHOT_5A   (1 << 3)
+#define ISL923X_C0_DCHOT_4A   (2 << 3)
+#define ISL923X_C0_DCHOT_3A   (3 << 3)
+#define ISL923X_C0_DCHOT_MASK (3 << 3)
+
+/* Control1: general purpose comparator debounce time in micro second */
+#define ISL923X_C1_GP_DEBOUNCE_2       (0 << 14)
+#define ISL923X_C1_GP_DEBOUNCE_12      (1 << 14)
+#define ISL923X_C1_GP_DEBOUNCE_2000    (2 << 14)
+#define ISL923X_C1_GP_DEBOUNCE_5000000 (3 << 14)
+#define ISL923X_C1_GP_DEBOUNCE_MASK    (3 << 14)
+
+/* Control1: learn mode */
+#define ISL923X_C1_LEARN_MODE_AUTOEXIT (1 << 13)
+#define ISL923X_C1_LEARN_MODE_ENABLE   (1 << 12)
+
+/* Control1: OTG enable */
+#define ISL923X_C1_OTG (1 << 11)
+
+/* Control1: audio filter */
+#define ISL923X_C1_AUDIO_FILTER (1 << 10)
+
+/* Control1: switch frequency, ISL9238 defines bit 7 as unused */
+#define ISL923X_C1_SWITCH_FREQ_PROG (0 << 7) /* 1000kHz or PROG */
+#define ISL9237_C1_SWITCH_FREQ_913K (1 << 7)
+#define ISL923X_C1_SWITCH_FREQ_839K (2 << 7)
+#define ISL9237_C1_SWITCH_FREQ_777K (3 << 7)
+#define ISL923X_C1_SWITCH_FREQ_723K (4 << 7)
+#define ISL9237_C1_SWITCH_FREQ_676K (5 << 7)
+#define ISL923X_C1_SWITCH_FREQ_635K (6 << 7)
+#define ISL9237_C1_SWITCH_FREQ_599K (7 << 7)
+#define ISL923X_C1_SWITCH_FREQ_MASK (7 << 7)
+
+/* Control1: turbo mode */
+#define ISL923X_C1_TURBO_MODE (1 << 6)
+
+/* Control1: AMON & BMON */
+#define ISL923X_C1_DISABLE_MON (1 << 5)
+#define ISL923X_C1_SELECT_BMON (1 << 4)
+
+/* Control1: PSYS, VSYS, VSYSLO */
+#define ISL923X_C1_ENABLE_PSYS (1 << 3)
+#define ISL923X_C1_ENABLE_VSYS (1 << 2)
+#define ISL923X_C1_VSYSLO_REF_6000 0
+#define ISL923X_C1_VSYSLO_REF_6300 1
+#define ISL923X_C1_VSYSLO_REF_6600 2
+#define ISL923X_C1_VSYSLO_REF_6900 3
+#define ISL923X_C1_VSYSLO_REF_MASK 3
+
+/* Control2: trickle charging current in mA */
+#define ISL923X_C2_TRICKLE_256  (0 << 14)
+#define ISL923X_C2_TRICKLE_128  (1 << 14)
+#define ISL923X_C2_TRICKLE_64   (2 << 14)
+#define ISL923X_C2_TRICKLE_512  (3 << 14)
+#define ISL923X_C2_TRICKLE_MASK (3 << 14)
+
+/* Control2: OTGEN debounce time in ms */
+#define ISL923X_C2_OTG_DEBOUNCE_1300 (0 << 13)
+#define ISL923X_C2_OTG_DEBOUNCE_150  (1 << 13)
+#define ISL923X_C2_OTG_DEBOUNCE_MASK (1 << 13)
+
+/* Control2: 2-level adapter over current */
+#define ISL923X_C2_2LVL_OVERCURRENT (1 << 12)
+
+/* Control2: adapter insertion debounce time in ms */
+#define ISL923X_C2_ADAPTER_DEBOUNCE_1300 (0 << 11)
+#define ISL923X_C2_ADAPTER_DEBOUNCE_150  (1 << 11)
+#define ISL923X_C2_ADAPTER_DEBOUNCE_MASK (1 << 11)
+
+/* Control2: PROCHOT debounce time in uS */
+#define ISL9238_C2_PROCHOT_DEBOUNCE_7    (0 << 9)
+#define ISL9237_C2_PROCHOT_DEBOUNCE_10   (0 << 9)
+#define ISL923X_C2_PROCHOT_DEBOUNCE_100  (1 << 9)
+#define ISL923X_C2_PROCHOT_DEBOUNCE_500  (2 << 9)
+#define ISL923X_C2_PROCHOT_DEBOUNCE_1000 (3 << 9)
+#define ISL923X_C2_PROCHOT_DEBOUNCE_MASK (3 << 9)
+
+/* Control2: min PROCHOT duration in uS */
+#define ISL923X_C2_PROCHOT_DURATION_10000 (0 << 6)
+#define ISL923X_C2_PROCHOT_DURATION_20000 (1 << 6)
+#define ISL923X_C2_PROCHOT_DURATION_15000 (2 << 6)
+#define ISL923X_C2_PROCHOT_DURATION_5000  (3 << 6)
+#define ISL923X_C2_PROCHOT_DURATION_1000  (4 << 6)
+#define ISL923X_C2_PROCHOT_DURATION_500   (5 << 6)
+#define ISL923X_C2_PROCHOT_DURATION_100   (6 << 6)
+#define ISL923X_C2_PROCHOT_DURATION_0     (7 << 6)
+#define ISL923X_C2_PROCHOT_DURATION_MASK  (7 << 6)
+
+/* Control2: turn off ASGATE in OTG mode */
+#define ISL923X_C2_ASGATE_OFF (1 << 5)
+
+/* Control2: CMIN, general purpose comparator reference in mV */
+#define ISL923X_C2_CMIN_2000 (0 << 4)
+#define ISL923X_C2_CMIN_1200 (1 << 4)
+
+/* Control2: general purpose comparator enable */
+#define ISL923X_C2_COMPARATOR (1 << 3)
+
+/* Control2: invert CMOUT, general purpose comparator output, polarity */
+#define ISL923X_C2_INVERT_CMOUT (1 << 2)
+
+/* Control2: disable WOC, way over current */
+#define ISL923X_C2_WOC_OFF (1 << 1)
+
+/* Control2: PSYS gain in uA/W (ISL9237 only) */
+#define ISL9237_C2_PSYS_GAIN (1 << 0)
+
+/* Control2: PSYS gain in uA/W (ISL9238 only) */
+#define ISL9238_C3_PSYS_GAIN (1 << 9)
+
+/* OTG voltage limit in mV, current limit in mA */
+#define ISL923X_OTG_VOLTAGE_MIN 4864
+#define ISL923X_OTG_VOLTAGE_MAX 5376
+#define ISL923X_OTG_CURRENT_MAX 4096
+
+/* Info register fields */
+#define ISL9237_INFO_PROG_RESISTOR_MASK 0xf
+#define ISL923X_INFO_TRICKLE_ACTIVE_MASK (1 << 4)
+#define ISL9237_INFO_PSTATE_SHIFT 5
+#define ISL9237_INFO_PSTATE_MASK 3
+
+enum isl9237_power_stage {
+	BUCK_MODE,
+	BOOST_MODE,
+	BUCK_BOOST_MODE,
+	REVERSE_BUCK_MODE
+};
+
+#define ISL9237_INFO_FSM_STATE_SHIFT 7
+#define ISL9237_INFO_FSM_STATE_MASK 7
+
+enum isl9237_fsm_state {
+	FSM_OFF,
+	FSM_BAT,
+	FSM_ADPT,
+	FSM_ACOK,
+	FSM_VSYS,
+	FSM_CHRG,
+	FSM_ENTOG,
+	FSM_OTG
+};
+
+#define ISL923X_INFO_VSYSLO (1 << 10)
+#define ISL923X_INFO_DCHOT (1 << 11)
+#define ISL9237_INFO_ACHOT (1 << 12)
+
+#if defined(CONFIG_CHARGER_ISL9237)
+#define CHARGER_NAME  "isl9237"
+#define CHARGE_V_MAX  ISL9237_SYS_VOLTAGE_REG_MAX
+#define CHARGE_V_MIN  ISL923X_SYS_VOLTAGE_REG_MIN
+#define CHARGE_V_STEP 8
+#elif defined(CONFIG_CHARGER_ISL9238)
+#define CHARGER_NAME  "isl9238"
+#define CHARGE_V_MAX  ISL9238_SYS_VOLTAGE_REG_MAX
+#define CHARGE_V_MIN  ISL923X_SYS_VOLTAGE_REG_MIN
+#define CHARGE_V_STEP 8
+#endif
+
+#define CHARGE_I_MAX  ISL923X_CURRENT_REG_MAX
+#define CHARGE_I_MIN  4
+#define CHARGE_I_OFF  0
+#define CHARGE_I_STEP 4
+#define INPUT_I_MAX   ISL923X_CURRENT_REG_MAX
+#define INPUT_I_MIN   4
+#define INPUT_I_STEP  4
+
+#define I2C_ADDR_CHARGER ISL923X_ADDR
+#endif /* __CROS_EC_ISL923X_H */
diff --git a/include/config.h b/include/config.h
index 15679582f8..ff23a7ec4e 100644
--- a/include/config.h
+++ b/include/config.h
@@ -390,6 +390,7 @@
 #undef CONFIG_CHARGER_BQ25892
 #undef CONFIG_CHARGER_BQ25895
 #undef CONFIG_CHARGER_ISL9237
+#undef CONFIG_CHARGER_ISL9238
 #undef CONFIG_CHARGER_TPS65090  /* Note: does not use CONFIG_CHARGER */
 
 /*