charger: Add Intersil charger ISL9237

ISL9237 is a buck-boost narrow output voltage DC charger. This change
provides interfaces to satisfy external dependencies for
charge_state_v2.

ISL9237's charging voltage control is different from smart battery
chargers. And there's no SBC compatible charging mode and status. So
this CL modified charger_set_voltage() behavior by controlling VSYS
voltage.

BRANCH=none
BUG=none
TEST=ran on reworked glados

Signed-off-by: Rong Chang <rongchang@chromium.org>
Change-Id: Ibbbf805bbbe1ee06f87a41cde3e39acbf2e105b4
Reviewed-on: https://chromium-review.googlesource.com/272882
Reviewed-by: Alec Berg <alecaberg@chromium.org>
Commit-Queue: Aaron Durbin <adurbin@chromium.org>
Trybot-Ready: Aaron Durbin <adurbin@chromium.org>
Tested-by: Aaron Durbin <adurbin@chromium.org>

3 files changed, 484 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index 997726fe24..aff6f45aa1 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -35,6 +35,7 @@ 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
 
 # I/O expander
 driver-$(CONFIG_IO_EXPANDER_PCA9534)+=ioexpander_pca9534.o
diff --git a/driver/charger/isl9237.c b/driver/charger/isl9237.c
new file mode 100644
index 0000000000..29257f85f7
--- /dev/null
+++ b/driver/charger/isl9237.c
@@ -0,0 +1,233 @@
+/* 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 ISL9237 battery charger driver.
+ */
+
+#include "battery.h"
+#include "battery_smart.h"
+#include "charger.h"
+#include "console.h"
+#include "common.h"
+#include "i2c.h"
+#include "isl9237.h"
+#include "util.h"
+
+#define DEFAULT_R_AC 20
+#define DEFAULT_R_SNS 10
+#define R_AC CONFIG_CHARGER_SENSE_RESISTOR_AC
+#define R_SNS CONFIG_CHARGER_SENSE_RESISTOR
+#define REG_TO_CURRENT(REG) ((REG) * DEFAULT_R_SNS / R_SNS)
+#define CURRENT_TO_REG(CUR) ((CUR) * R_SNS / DEFAULT_R_SNS)
+#define AC_REG_TO_CURRENT(REG) ((REG) * DEFAULT_R_AC / R_AC)
+#define AC_CURRENT_TO_REG(CUR) ((CUR) * R_AC / DEFAULT_R_AC)
+
+/* Charger parameters */
+static const struct charger_info isl9237_charger_info = {
+	.name         = CHARGER_NAME,
+	.voltage_max  = CHARGE_V_MAX,
+	.voltage_min  = CHARGE_V_MIN,
+	.voltage_step = CHARGE_V_STEP,
+	.current_max  = REG_TO_CURRENT(CHARGE_I_MAX),
+	.current_min  = REG_TO_CURRENT(CHARGE_I_MIN),
+	.current_step = REG_TO_CURRENT(CHARGE_I_STEP),
+	.input_current_max  = AC_REG_TO_CURRENT(INPUT_I_MAX),
+	.input_current_min  = AC_REG_TO_CURRENT(INPUT_I_MIN),
+	.input_current_step = AC_REG_TO_CURRENT(INPUT_I_STEP),
+};
+
+static inline int raw_read8(int offset, int *value)
+{
+	return i2c_read8(I2C_PORT_CHARGER, I2C_ADDR_CHARGER, offset, value);
+}
+
+static inline int raw_read16(int offset, int *value)
+{
+	return i2c_read16(I2C_PORT_CHARGER, I2C_ADDR_CHARGER, offset, value);
+}
+
+static inline int raw_write16(int offset, int value)
+{
+	return i2c_write16(I2C_PORT_CHARGER, I2C_ADDR_CHARGER, offset, value);
+}
+
+static int isl9237_set_current(uint16_t current)
+{
+	return raw_write16(ISL9237_REG_CHG_CURRENT, CURRENT_TO_REG(current));
+}
+
+static int isl9237_set_voltage(uint16_t voltage)
+{
+	return raw_write16(ISL9237_REG_SYS_VOLTAGE_MAX, voltage);
+}
+
+/* chip specific interfaces */
+
+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);
+	if (rv)
+		return rv;
+
+	return raw_write16(ISL9237_REG_ADAPTER_CURRENT2, reg);
+}
+
+int charger_get_input_current(int *input_current)
+{
+	int rv;
+	int reg;
+
+	rv = raw_read16(ISL9237_REG_ADAPTER_CURRENT1, &reg);
+	if (rv)
+		return rv;
+
+	*input_current = AC_REG_TO_CURRENT(reg);
+	return EC_SUCCESS;
+}
+
+int charger_manufacturer_id(int *id)
+{
+	int rv;
+	int reg;
+
+	rv = raw_read16(ISL9237_REG_MANUFACTURER_ID, &reg);
+	if (rv)
+		return rv;
+
+	*id = reg;
+	return EC_SUCCESS;
+}
+
+int charger_device_id(int *id)
+{
+	int rv;
+	int reg;
+
+	rv = raw_read16(ISL9237_REG_DEVICE_ID, &reg);
+	if (rv)
+		return rv;
+
+	*id = reg;
+	return EC_SUCCESS;
+}
+
+int charger_get_option(int *option)
+{
+	int rv;
+	uint32_t controls;
+	int reg;
+
+	rv = raw_read8(ISL9237_REG_CONTROL0, &reg);
+	if (rv)
+		return rv;
+
+	controls = reg;
+	rv = raw_read16(ISL9237_REG_CONTROL1, &reg);
+	if (rv)
+		return rv;
+
+	controls |= reg << 16;
+	*option = controls;
+	return EC_SUCCESS;
+}
+
+int charger_set_option(int option)
+{
+	int rv;
+	uint16_t reg;
+
+	reg = option & 0xffff;
+	rv = raw_write16(ISL9237_REG_CONTROL0, reg);
+
+	if (rv)
+		return rv;
+
+	reg = (option >> 16) & 0xffff;
+	return raw_write16(ISL9237_REG_CONTROL1, reg);
+}
+
+/* Charger interfaces */
+
+const struct charger_info *charger_get_info(void)
+{
+	return &isl9237_charger_info;
+}
+
+int charger_get_status(int *status)
+{
+	*status = CHARGER_LEVEL_2;
+
+	return EC_SUCCESS;
+}
+
+int charger_set_mode(int mode)
+{
+	/* ISL9237 does not support inhibit mode setting. */
+	return EC_SUCCESS;
+}
+
+int charger_get_current(int *current)
+{
+	int rv;
+	int reg;
+
+	rv = raw_read16(ISL9237_REG_CHG_CURRENT, &reg);
+	if (rv)
+		return rv;
+
+	*current = REG_TO_CURRENT(reg);
+	return EC_SUCCESS;
+}
+
+int charger_set_current(int current)
+{
+	return isl9237_set_current(current);
+}
+
+int charger_get_voltage(int *voltage)
+{
+	return raw_read16(ISL9237_REG_SYS_VOLTAGE_MAX, voltage);
+}
+
+int charger_set_voltage(int voltage)
+{
+	/* The ISL9237 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
+	 * only can regulate the system voltage which will kill the board's
+	 * power if below 0. */
+	if (voltage == 0) {
+		const struct battery_info *bi = battery_get_info();
+		voltage = bi->voltage_min;
+	}
+
+	return isl9237_set_voltage(voltage);
+}
+
+int charger_post_init(void)
+{
+	return EC_SUCCESS;
+}
+
+int charger_discharge_on_ac(int enable)
+{
+	int rv;
+	int control1;
+
+	rv = raw_read16(ISL9237_REG_CONTROL1, &control1);
+	if (rv)
+		return rv;
+
+	control1 &= ~ISL9237_C1_LEARN_MODE_AUTOEXIT;
+	if (enable)
+		control1 |= ISL9237_C1_LEARN_MODE_ENABLE;
+	else
+		control1 &= ~ISL9237_C1_LEARN_MODE_ENABLE;
+
+	return raw_write16(ISL9237_REG_CONTROL1, control1);
+}
+
diff --git a/driver/charger/isl9237.h b/driver/charger/isl9237.h
new file mode 100644
index 0000000000..30e5ed970d
--- /dev/null
+++ b/driver/charger/isl9237.h
@@ -0,0 +1,250 @@
+/* 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_CHARGER_ISL9237_H
+#define __CROS_EC_CHARGER_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_PROCHOT_TIME     0x39
+#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_44 0
+#define ISL9237_C2_PSYS_GAIN_0_36 1
+
+/* 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_CHARGER_ISL9237_H */