* [PATCH v5 2/2] power: supply: Add support for Maxim MAX8971 charger
2025-03-20 7:29 [PATCH v5 0/2] power: supply: Add support for Maxim MAX8971 charger Svyatoslav Ryhel
2025-03-20 7:29 ` [PATCH v5 1/2] dt-bindings: power: supply: Document " Svyatoslav Ryhel
@ 2025-03-20 7:29 ` Svyatoslav Ryhel
2025-04-08 5:40 ` Svyatoslav Ryhel
1 sibling, 1 reply; 5+ messages in thread
From: Svyatoslav Ryhel @ 2025-03-20 7:29 UTC (permalink / raw)
To: Sebastian Reichel, Krzysztof Kozlowski, Conor Dooley,
Svyatoslav Ryhel
Cc: linux-pm, devicetree, linux-kernel
The MAX8971 is a compact, high-frequency, high-efficiency switch-mode
charger for a one-cell lithium-ion (Li+) battery.
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
Documentation/ABI/testing/sysfs-class-power | 43 ++
drivers/power/supply/Kconfig | 14 +
drivers/power/supply/Makefile | 1 +
drivers/power/supply/max8971_charger.c | 750 ++++++++++++++++++++
4 files changed, 808 insertions(+)
create mode 100644 drivers/power/supply/max8971_charger.c
diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power
index 45180b62d426..9053431def5f 100644
--- a/Documentation/ABI/testing/sysfs-class-power
+++ b/Documentation/ABI/testing/sysfs-class-power
@@ -793,3 +793,46 @@ Description:
Access: Read
Valid values: 1-31
+
+What: /sys/class/power_supply/max8971-charger/fast_charge_timer
+Date: March 2025
+KernelVersion: 6.14.0
+Contact: Svyatoslav Ryhel <clamor95@gmail.com>
+Description:
+ This entry shows and sets the maximum time the max8971
+ charger operates in fast-charge mode. When the timer expires
+ the device will terminate fast-charge mode (charging current
+ will drop to 0 A) and will trigger interrupt.
+
+ Valid values:
+
+ - 4 - 10 (hours), step by 1
+ - 0: disabled.
+
+What: /sys/class/power_supply/max8971-charger/top_off_threshold_current
+Date: March 2025
+KernelVersion: 6.14.0
+Contact: Svyatoslav Ryhel <clamor95@gmail.com>
+Description:
+ This entry shows and sets the charging current threshold for
+ entering top-off charging mode. When charging current in fast
+ charge mode drops below this value, the charger will trigger
+ interrupt and start top-off charging mode.
+
+ Valid values:
+
+ - 50000 - 200000 (microamps), step by 50000 (rounded down)
+
+What: /sys/class/power_supply/max8971-charger/top_off_timer
+Date: March 2025
+KernelVersion: 6.14.0
+Contact: Svyatoslav Ryhel <clamor95@gmail.com>
+Description:
+ This entry shows and sets the maximum time the max8971
+ charger operates in top-off charge mode. When the timer expires
+ the device will terminate top-off charge mode (charging current
+ will drop to 0 A) and will trigger interrupt.
+
+ Valid values:
+
+ - 0 - 70 (minutes), step by 10 (rounded down)
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 9f2eef6787f7..7c86116c2947 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -595,6 +595,20 @@ config CHARGER_MAX77976
This driver can also be built as a module. If so, the module will be
called max77976_charger.
+config CHARGER_MAX8971
+ tristate "Maxim MAX8971 battery charger driver"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ The MAX8971 is a compact, high-frequency, high-efficiency switch-mode
+ charger for a one-cell lithium-ion (Li+) battery. It delivers up to
+ 1.55A of current to the battery from inputs up to 7.5V and withstands
+ transient inputs up to 22V.
+
+ Say Y to enable support for the Maxim MAX8971 battery charger.
+ This driver can also be built as a module. If so, the module will be
+ called max8971_charger.
+
config CHARGER_MAX8997
tristate "Maxim MAX8997/MAX8966 PMIC battery charger driver"
depends on MFD_MAX8997 && REGULATOR_MAX8997
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 59c4a9f40d28..8fa051ff87ff 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_CHARGER_DETECTOR_MAX14656) += max14656_charger_detector.o
obj-$(CONFIG_CHARGER_MAX77650) += max77650-charger.o
obj-$(CONFIG_CHARGER_MAX77693) += max77693_charger.o
obj-$(CONFIG_CHARGER_MAX77976) += max77976_charger.o
+obj-$(CONFIG_CHARGER_MAX8971) += max8971_charger.o
obj-$(CONFIG_CHARGER_MAX8997) += max8997_charger.o
obj-$(CONFIG_CHARGER_MAX8998) += max8998_charger.o
obj-$(CONFIG_CHARGER_MP2629) += mp2629_charger.o
diff --git a/drivers/power/supply/max8971_charger.c b/drivers/power/supply/max8971_charger.c
new file mode 100644
index 000000000000..65ff04bb4c33
--- /dev/null
+++ b/drivers/power/supply/max8971_charger.c
@@ -0,0 +1,750 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/devm-helpers.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/extcon.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of_graph.h>
+#include <linux/property.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#define MAX8971_REG_CHGINT 0x0f
+#define MAX8971_REG_CHG_RST BIT(0)
+#define MAX8971_REG_CHGINT_MASK 0x01
+#define MAX8971_AICL_MASK BIT(7)
+#define MAX8971_REG_CHG_STAT 0x02
+#define MAX8971_CHG_MASK BIT(3)
+#define MAX8971_REG_DETAILS1 0x03
+#define MAX8971_REG_DETAILS2 0x04
+#define MAX8971_REG_CHGCNTL1 0x05
+#define MAX8971_REG_FCHGCRNT 0x06
+#define MAX8971_REG_DCCRNT 0x07
+#define MAX8971_CHGRSTRT_MASK BIT(6)
+#define MAX8971_REG_TOPOFF 0x08
+#define MAX8971_REG_TEMPREG 0x09
+#define MAX8971_REG_PROTCMD 0x0a
+#define MAX8971_CHGPROT_LOCKED 0x00
+#define MAX8971_CHGPROT_UNLOCKED 0x03
+
+#define MAX8971_FCHGT_DEFAULT 2
+#define MAX8971_TOPOFFT_DEFAULT 3
+
+static const char *max8971_manufacturer = "Maxim Integrated";
+static const char *max8971_model = "MAX8971";
+
+enum max8971_charging_state {
+ MAX8971_CHARGING_DEAD_BATTERY,
+ MAX8971_CHARGING_PREQUALIFICATION,
+ MAX8971_CHARGING_FAST_CONST_CURRENT,
+ MAX8971_CHARGING_FAST_CONST_VOLTAGE,
+ MAX8971_CHARGING_TOP_OFF,
+ MAX8971_CHARGING_DONE,
+ MAX8971_CHARGING_TIMER_FAULT,
+ MAX8971_CHARGING_SUSPENDED_THERMAL,
+ MAX8971_CHARGING_OFF,
+ MAX8971_CHARGING_THERMAL_LOOP,
+};
+
+enum max8971_health_state {
+ MAX8971_HEALTH_UNKNOWN,
+ MAX8971_HEALTH_COLD,
+ MAX8971_HEALTH_COOL,
+ MAX8971_HEALTH_WARM,
+ MAX8971_HEALTH_HOT,
+ MAX8971_HEALTH_OVERHEAT,
+};
+
+/* Fast-Charge current limit, 250..1550 mA, 50 mA steps */
+#define MAX8971_CHG_CC_STEP 50000U
+#define MAX8971_CHG_CC_MIN 250000U
+#define MAX8971_CHG_CC_MAX 1550000U
+
+/* Input current limit, 250..1500 mA, 25 mA steps */
+#define MAX8971_DCILMT_STEP 25000U
+#define MAX8971_DCILMT_MIN 250000U
+#define MAX8971_DCILMT_MAX 1500000U
+
+enum max8971_field_idx {
+ THM_DTLS, /* DETAILS1 */
+ BAT_DTLS, CHG_DTLS, /* DETAILS2 */
+ CHG_CC, FCHG_T, /* FCHGCRNT */
+ DCI_LMT, /* DCCRNT */
+ TOPOFF_T, TOPOFF_S, /* TOPOFF */
+ CPROT, /* PROTCMD */
+ MAX8971_N_REGMAP_FIELDS
+};
+
+static const struct reg_field max8971_reg_field[MAX8971_N_REGMAP_FIELDS] = {
+ [THM_DTLS] = REG_FIELD(MAX8971_REG_DETAILS1, 0, 2),
+ [BAT_DTLS] = REG_FIELD(MAX8971_REG_DETAILS2, 4, 5),
+ [CHG_DTLS] = REG_FIELD(MAX8971_REG_DETAILS2, 0, 3),
+ [CHG_CC] = REG_FIELD(MAX8971_REG_FCHGCRNT, 0, 4),
+ [FCHG_T] = REG_FIELD(MAX8971_REG_FCHGCRNT, 5, 7),
+ [DCI_LMT] = REG_FIELD(MAX8971_REG_DCCRNT, 0, 5),
+ [TOPOFF_T] = REG_FIELD(MAX8971_REG_TOPOFF, 5, 7),
+ [TOPOFF_S] = REG_FIELD(MAX8971_REG_TOPOFF, 2, 3),
+ [CPROT] = REG_FIELD(MAX8971_REG_PROTCMD, 2, 3),
+};
+
+static const struct regmap_config max8971_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = MAX8971_REG_CHGINT,
+};
+
+struct max8971_data {
+ struct device *dev;
+ struct power_supply *psy_mains;
+
+ struct extcon_dev *edev;
+ struct notifier_block extcon_nb;
+ struct delayed_work extcon_work;
+
+ struct regmap *regmap;
+ struct regmap_field *rfield[MAX8971_N_REGMAP_FIELDS];
+
+ enum power_supply_usb_type usb_type;
+
+ u32 fchgt;
+ u32 tofft;
+ u32 toffs;
+
+ bool present;
+};
+
+static int max8971_get_status(struct max8971_data *priv, int *val)
+{
+ u32 regval;
+ int err;
+
+ err = regmap_field_read(priv->rfield[CHG_DTLS], ®val);
+ if (err)
+ return err;
+
+ switch (regval) {
+ case MAX8971_CHARGING_DEAD_BATTERY:
+ case MAX8971_CHARGING_PREQUALIFICATION:
+ case MAX8971_CHARGING_FAST_CONST_CURRENT:
+ case MAX8971_CHARGING_FAST_CONST_VOLTAGE:
+ case MAX8971_CHARGING_TOP_OFF:
+ case MAX8971_CHARGING_THERMAL_LOOP:
+ *val = POWER_SUPPLY_STATUS_CHARGING;
+ break;
+ case MAX8971_CHARGING_DONE:
+ *val = POWER_SUPPLY_STATUS_FULL;
+ break;
+ case MAX8971_CHARGING_TIMER_FAULT:
+ *val = POWER_SUPPLY_STATUS_NOT_CHARGING;
+ break;
+ case MAX8971_CHARGING_OFF:
+ case MAX8971_CHARGING_SUSPENDED_THERMAL:
+ *val = POWER_SUPPLY_STATUS_DISCHARGING;
+ break;
+ default:
+ *val = POWER_SUPPLY_STATUS_UNKNOWN;
+ }
+
+ return 0;
+}
+
+static int max8971_get_charge_type(struct max8971_data *priv, int *val)
+{
+ u32 regval;
+ int err;
+
+ err = regmap_field_read(priv->rfield[CHG_DTLS], ®val);
+ if (err)
+ return err;
+
+ switch (regval) {
+ case MAX8971_CHARGING_DEAD_BATTERY:
+ case MAX8971_CHARGING_PREQUALIFICATION:
+ *val = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+ break;
+ case MAX8971_CHARGING_FAST_CONST_CURRENT:
+ case MAX8971_CHARGING_FAST_CONST_VOLTAGE:
+ *val = POWER_SUPPLY_CHARGE_TYPE_FAST;
+ break;
+ case MAX8971_CHARGING_TOP_OFF:
+ case MAX8971_CHARGING_THERMAL_LOOP:
+ *val = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
+ break;
+ case MAX8971_CHARGING_DONE:
+ case MAX8971_CHARGING_TIMER_FAULT:
+ case MAX8971_CHARGING_SUSPENDED_THERMAL:
+ case MAX8971_CHARGING_OFF:
+ *val = POWER_SUPPLY_CHARGE_TYPE_NONE;
+ break;
+ default:
+ *val = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+ }
+
+ return 0;
+}
+
+static int max8971_get_health(struct max8971_data *priv, int *val)
+{
+ u32 regval;
+ int err;
+
+ err = regmap_field_read(priv->rfield[THM_DTLS], ®val);
+ if (err)
+ return err;
+
+ switch (regval) {
+ case MAX8971_HEALTH_COLD:
+ *val = POWER_SUPPLY_HEALTH_COLD;
+ break;
+ case MAX8971_HEALTH_COOL:
+ *val = POWER_SUPPLY_HEALTH_COOL;
+ break;
+ case MAX8971_HEALTH_WARM:
+ *val = POWER_SUPPLY_HEALTH_GOOD;
+ break;
+ case MAX8971_HEALTH_HOT:
+ *val = POWER_SUPPLY_HEALTH_HOT;
+ break;
+ case MAX8971_HEALTH_OVERHEAT:
+ *val = POWER_SUPPLY_HEALTH_OVERHEAT;
+ break;
+ case MAX8971_HEALTH_UNKNOWN:
+ default:
+ *val = POWER_SUPPLY_HEALTH_UNKNOWN;
+ }
+
+ return 0;
+}
+
+static int max8971_get_online(struct max8971_data *priv, int *val)
+{
+ u32 regval;
+ int err;
+
+ err = regmap_read(priv->regmap, MAX8971_REG_CHG_STAT, ®val);
+ if (err)
+ return err;
+
+ if (priv->present)
+ /* CHG_OK bit is 0 when charger is online */
+ *val = !(regval & MAX8971_CHG_MASK);
+ else
+ *val = priv->present;
+
+ return 0;
+}
+
+static int max8971_get_integer(struct max8971_data *priv, enum max8971_field_idx fidx,
+ u32 clamp_min, u32 clamp_max, u32 mult, int *val)
+{
+ u32 regval;
+ int err;
+
+ err = regmap_field_read(priv->rfield[fidx], ®val);
+ if (err)
+ return err;
+
+ *val = clamp_val(regval * mult, clamp_min, clamp_max);
+
+ return 0;
+}
+
+static int max8971_set_integer(struct max8971_data *priv, enum max8971_field_idx fidx,
+ u32 clamp_min, u32 clamp_max, u32 div, int val)
+{
+ u32 regval;
+
+ regval = clamp_val(val, clamp_min, clamp_max) / div;
+
+ return regmap_field_write(priv->rfield[fidx], regval);
+}
+
+static int max8971_get_property(struct power_supply *psy, enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct max8971_data *priv = power_supply_get_drvdata(psy);
+ int err = 0;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ err = max8971_get_status(priv, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ err = max8971_get_charge_type(priv, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_USB_TYPE:
+ val->intval = priv->usb_type;
+ break;
+ case POWER_SUPPLY_PROP_HEALTH:
+ err = max8971_get_health(priv, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_ONLINE:
+ err = max8971_get_online(priv, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_PRESENT:
+ val->intval = priv->present;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+ val->intval = MAX8971_CHG_CC_MAX;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+ err = max8971_get_integer(priv, CHG_CC, MAX8971_CHG_CC_MIN, MAX8971_CHG_CC_MAX,
+ MAX8971_CHG_CC_STEP, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ err = max8971_get_integer(priv, DCI_LMT, MAX8971_DCILMT_MIN, MAX8971_DCILMT_MAX,
+ MAX8971_DCILMT_STEP, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_MODEL_NAME:
+ val->strval = max8971_model;
+ break;
+ case POWER_SUPPLY_PROP_MANUFACTURER:
+ val->strval = max8971_manufacturer;
+ break;
+ default:
+ err = -EINVAL;
+ }
+
+ return err;
+}
+
+static int max8971_set_property(struct power_supply *psy, enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct max8971_data *priv = power_supply_get_drvdata(psy);
+ int err = 0;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+ err = max8971_set_integer(priv, CHG_CC, MAX8971_CHG_CC_MIN, MAX8971_CHG_CC_MAX,
+ MAX8971_CHG_CC_STEP, val->intval);
+ break;
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ err = max8971_set_integer(priv, DCI_LMT, MAX8971_DCILMT_MIN, MAX8971_DCILMT_MAX,
+ MAX8971_DCILMT_STEP, val->intval);
+ break;
+ default:
+ err = -EINVAL;
+ }
+
+ return err;
+};
+
+static int max8971_property_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static enum power_supply_property max8971_properties[] = {
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_CHARGE_TYPE,
+ POWER_SUPPLY_PROP_USB_TYPE,
+ POWER_SUPPLY_PROP_HEALTH,
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_PRESENT,
+ POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
+ POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
+ POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+ POWER_SUPPLY_PROP_MODEL_NAME,
+ POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static const struct power_supply_desc max8971_charger_desc = {
+ .name = "max8971-charger",
+ .type = POWER_SUPPLY_TYPE_USB,
+ .usb_types = BIT(POWER_SUPPLY_USB_TYPE_UNKNOWN) |
+ BIT(POWER_SUPPLY_USB_TYPE_SDP) |
+ BIT(POWER_SUPPLY_USB_TYPE_DCP) |
+ BIT(POWER_SUPPLY_USB_TYPE_CDP) |
+ BIT(POWER_SUPPLY_USB_TYPE_ACA),
+ .properties = max8971_properties,
+ .num_properties = ARRAY_SIZE(max8971_properties),
+ .get_property = max8971_get_property,
+ .set_property = max8971_set_property,
+ .property_is_writeable = max8971_property_is_writeable,
+};
+
+static void max8971_update_config(struct max8971_data *priv)
+{
+ regmap_field_write(priv->rfield[CPROT], MAX8971_CHGPROT_UNLOCKED);
+
+ if (priv->fchgt != MAX8971_FCHGT_DEFAULT)
+ regmap_field_write(priv->rfield[FCHG_T], priv->fchgt);
+
+ regmap_write_bits(priv->regmap, MAX8971_REG_DCCRNT, MAX8971_CHGRSTRT_MASK,
+ MAX8971_CHGRSTRT_MASK);
+
+ if (priv->tofft != MAX8971_TOPOFFT_DEFAULT)
+ regmap_field_write(priv->rfield[TOPOFF_T], priv->tofft);
+
+ if (priv->toffs)
+ regmap_field_write(priv->rfield[TOPOFF_S], priv->toffs);
+
+ regmap_field_write(priv->rfield[CPROT], MAX8971_CHGPROT_LOCKED);
+}
+
+static ssize_t fast_charge_timer_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct max8971_data *priv = power_supply_get_drvdata(psy);
+ u32 regval;
+ int err;
+
+ err = regmap_field_read(priv->rfield[FCHG_T], ®val);
+ if (err)
+ return err;
+
+ switch (regval) {
+ case 0x1 ... 0x7:
+ /* Time is off by 3 hours comparing to value */
+ regval += 3;
+ break;
+ case 0x0:
+ default:
+ regval = 0;
+ break;
+ }
+
+ return sysfs_emit(buf, "%u\n", regval);
+}
+
+static ssize_t fast_charge_timer_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct max8971_data *priv = power_supply_get_drvdata(psy);
+ unsigned long hours;
+ int val, err;
+
+ err = kstrtoul(buf, 10, &hours);
+ if (err)
+ return err;
+
+ val = hours - 3;
+ if (val <= 0 || val > 7)
+ priv->fchgt = 0;
+ else
+ priv->fchgt = val;
+
+ max8971_update_config(priv);
+
+ return count;
+}
+
+static ssize_t top_off_threshold_current_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct max8971_data *priv = power_supply_get_drvdata(psy);
+ u32 regval, val;
+ int err;
+
+ err = regmap_field_read(priv->rfield[TOPOFF_S], ®val);
+ if (err)
+ return err;
+
+ /* 50uA start with 50uA step */
+ val = regval * 50 + 50;
+ val *= 1000;
+
+ return sysfs_emit(buf, "%u\n", val);
+}
+
+static ssize_t top_off_threshold_current_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct max8971_data *priv = power_supply_get_drvdata(psy);
+ unsigned long uamp;
+ int err;
+
+ err = kstrtoul(buf, 10, &uamp);
+ if (err)
+ return err;
+
+ if (uamp < 50000 || uamp > 200000)
+ return -EINVAL;
+
+ priv->toffs = uamp / 50000 - 1;
+
+ max8971_update_config(priv);
+
+ return count;
+}
+
+static ssize_t top_off_timer_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct max8971_data *priv = power_supply_get_drvdata(psy);
+ u32 regval;
+ int err;
+
+ err = regmap_field_read(priv->rfield[TOPOFF_T], ®val);
+ if (err)
+ return err;
+
+ /* 10 min intervals */
+ regval *= 10;
+
+ return sysfs_emit(buf, "%u\n", regval);
+}
+
+static ssize_t top_off_timer_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct power_supply *psy = to_power_supply(dev);
+ struct max8971_data *priv = power_supply_get_drvdata(psy);
+ unsigned long minutes;
+ int err;
+
+ err = kstrtoul(buf, 10, &minutes);
+ if (err)
+ return err;
+
+ if (minutes > 70)
+ return -EINVAL;
+
+ priv->tofft = minutes / 10;
+
+ max8971_update_config(priv);
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(fast_charge_timer);
+static DEVICE_ATTR_RW(top_off_threshold_current);
+static DEVICE_ATTR_RW(top_off_timer);
+
+static struct attribute *max8971_attrs[] = {
+ &dev_attr_fast_charge_timer.attr,
+ &dev_attr_top_off_threshold_current.attr,
+ &dev_attr_top_off_timer.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(max8971);
+
+static void max8971_extcon_evt_worker(struct work_struct *work)
+{
+ struct max8971_data *priv =
+ container_of(work, struct max8971_data, extcon_work.work);
+ struct device *dev = priv->dev;
+ struct extcon_dev *edev = priv->edev;
+ u32 chgcc, dcilmt;
+
+ if (extcon_get_state(edev, EXTCON_CHG_USB_SDP) > 0) {
+ dev_dbg(dev, "USB SDP charger is connected\n");
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_SDP;
+ chgcc = 500000;
+ dcilmt = 500000;
+ } else if (extcon_get_state(edev, EXTCON_USB) > 0) {
+ dev_dbg(dev, "USB charger is connected\n");
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_SDP;
+ chgcc = 500000;
+ dcilmt = 500000;
+ } else if (extcon_get_state(edev, EXTCON_DISP_MHL) > 0) {
+ dev_dbg(dev, "MHL plug is connected\n");
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_SDP;
+ chgcc = 500000;
+ dcilmt = 500000;
+ } else if (extcon_get_state(edev, EXTCON_CHG_USB_DCP) > 0) {
+ dev_dbg(dev, "USB DCP charger is connected\n");
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_DCP;
+ chgcc = 900000;
+ dcilmt = 1200000;
+ } else if (extcon_get_state(edev, EXTCON_CHG_USB_FAST) > 0) {
+ dev_dbg(dev, "USB FAST charger is connected\n");
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_ACA;
+ chgcc = 900000;
+ dcilmt = 1200000;
+ } else if (extcon_get_state(edev, EXTCON_CHG_USB_SLOW) > 0) {
+ dev_dbg(dev, "USB SLOW charger is connected\n");
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_ACA;
+ chgcc = 900000;
+ dcilmt = 1200000;
+ } else if (extcon_get_state(edev, EXTCON_CHG_USB_CDP) > 0) {
+ dev_dbg(dev, "USB CDP charger is connected\n");
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_CDP;
+ chgcc = 900000;
+ dcilmt = 1200000;
+ } else {
+ dev_dbg(dev, "USB state is unknown\n");
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_UNKNOWN;
+ return;
+ }
+
+ regmap_field_write(priv->rfield[CPROT], MAX8971_CHGPROT_UNLOCKED);
+
+ max8971_set_integer(priv, CHG_CC, MAX8971_CHG_CC_MIN, MAX8971_CHG_CC_MAX,
+ MAX8971_CHG_CC_STEP, chgcc);
+ max8971_set_integer(priv, DCI_LMT, MAX8971_DCILMT_MIN, MAX8971_DCILMT_MAX,
+ MAX8971_DCILMT_STEP, dcilmt);
+
+ regmap_field_write(priv->rfield[CPROT], MAX8971_CHGPROT_LOCKED);
+}
+
+static int extcon_get_charger_type(struct notifier_block *nb,
+ unsigned long state, void *data)
+{
+ struct max8971_data *priv =
+ container_of(nb, struct max8971_data, extcon_nb);
+ schedule_delayed_work(&priv->extcon_work, 0);
+ return NOTIFY_OK;
+}
+
+static irqreturn_t max8971_interrupt(int irq, void *dev_id)
+{
+ struct max8971_data *priv = dev_id;
+ struct device *dev = priv->dev;
+ int err, state;
+
+ err = regmap_read(priv->regmap, MAX8971_REG_CHGINT, &state);
+ if (err)
+ dev_err(dev, "interrupt reg read failed %d\n", err);
+
+ err = regmap_write_bits(priv->regmap, MAX8971_REG_CHGINT_MASK,
+ MAX8971_AICL_MASK, MAX8971_AICL_MASK);
+ if (err)
+ dev_err(dev, "failed to mask IRQ\n");
+
+ /* set presence prop */
+ priv->present = state & MAX8971_REG_CHG_RST;
+
+ /* on every plug chip resets to default */
+ if (priv->present)
+ max8971_update_config(priv);
+
+ /* update supply status */
+ power_supply_changed(priv->psy_mains);
+
+ return IRQ_HANDLED;
+}
+
+static int max8971_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct max8971_data *priv;
+ struct device_node *extcon;
+ struct power_supply_config cfg = { };
+ int err, i;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+ priv->usb_type = POWER_SUPPLY_USB_TYPE_UNKNOWN;
+
+ i2c_set_clientdata(client, priv);
+
+ priv->regmap = devm_regmap_init_i2c(client, &max8971_regmap_config);
+ if (IS_ERR(priv->regmap))
+ return dev_err_probe(dev, PTR_ERR(priv->regmap), "cannot allocate regmap\n");
+
+ for (i = 0; i < MAX8971_N_REGMAP_FIELDS; i++) {
+ priv->rfield[i] = devm_regmap_field_alloc(dev, priv->regmap, max8971_reg_field[i]);
+ if (IS_ERR(priv->rfield[i]))
+ return dev_err_probe(dev, PTR_ERR(priv->rfield[i]),
+ "cannot allocate regmap field\n");
+ }
+
+ cfg.attr_grp = max8971_groups;
+ cfg.drv_data = priv;
+ cfg.fwnode = dev_fwnode(dev);
+
+ priv->psy_mains = devm_power_supply_register(dev, &max8971_charger_desc, &cfg);
+ if (IS_ERR(priv->psy_mains))
+ return dev_err_probe(dev, PTR_ERR(priv->psy_mains),
+ "failed to register mains supply\n");
+
+ err = regmap_write_bits(priv->regmap, MAX8971_REG_CHGINT_MASK, MAX8971_AICL_MASK,
+ MAX8971_AICL_MASK);
+ if (err)
+ return dev_err_probe(dev, err, "failed to mask IRQ\n");
+
+ err = devm_request_threaded_irq(dev, client->irq, NULL, &max8971_interrupt,
+ IRQF_ONESHOT | IRQF_SHARED, client->name, priv);
+ if (err)
+ return dev_err_probe(dev, err, "failed to register IRQ %d\n", client->irq);
+
+ extcon = of_graph_get_remote_node(dev->of_node, -1, -1);
+ if (!extcon)
+ return 0;
+
+ priv->edev = extcon_find_edev_by_node(extcon);
+ of_node_put(extcon);
+ if (IS_ERR(priv->edev))
+ return dev_err_probe(dev, PTR_ERR(priv->edev), "failed to find extcon\n");
+
+ err = devm_delayed_work_autocancel(dev, &priv->extcon_work,
+ max8971_extcon_evt_worker);
+ if (err)
+ return dev_err_probe(dev, err, "failed to add extcon evt stop action\n");
+
+ priv->extcon_nb.notifier_call = extcon_get_charger_type;
+
+ err = devm_extcon_register_notifier_all(dev, priv->edev, &priv->extcon_nb);
+ if (err)
+ return dev_err_probe(dev, err, "failed to register notifier\n");
+
+ /* Initial configuration work with 1 sec delay */
+ schedule_delayed_work(&priv->extcon_work, msecs_to_jiffies(1000));
+
+ return 0;
+}
+
+static int __maybe_unused max8971_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct max8971_data *priv = i2c_get_clientdata(client);
+
+ irq_wake_thread(client->irq, priv);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(max8971_pm_ops, NULL, max8971_resume);
+
+static const struct of_device_id max8971_match_ids[] = {
+ { .compatible = "maxim,max8971" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, max8971_match_ids);
+
+static const struct i2c_device_id max8971_i2c_id[] = {
+ { "max8971" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max8971_i2c_id);
+
+static struct i2c_driver max8971_driver = {
+ .driver = {
+ .name = "max8971-charger",
+ .of_match_table = max8971_match_ids,
+ .pm = &max8971_pm_ops,
+ },
+ .probe = max8971_probe,
+ .id_table = max8971_i2c_id,
+};
+module_i2c_driver(max8971_driver);
+
+MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
+MODULE_DESCRIPTION("MAX8971 Charger Driver");
+MODULE_LICENSE("GPL");
--
2.43.0
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