--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * max77976_charger.c - Driver for the Maxim MAX77976 battery charger
+ *
+ * Copyright (C) 2021 Luca Ceresoli
+ * Author: Luca Ceresoli <luca@lucaceresoli.net>
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+
+#define MAX77976_DRIVER_NAME "max77976-charger"
+#define MAX77976_CHIP_ID 0x76
+
+static const char *max77976_manufacturer = "Maxim Integrated";
+static const char *max77976_model = "MAX77976";
+
+/* --------------------------------------------------------------------------
+ * Register map
+ */
+
+#define MAX77976_REG_CHIP_ID 0x00
+#define MAX77976_REG_CHIP_REVISION 0x01
+#define MAX77976_REG_CHG_INT_OK 0x12
+#define MAX77976_REG_CHG_DETAILS_01 0x14
+#define MAX77976_REG_CHG_CNFG_00 0x16
+#define MAX77976_REG_CHG_CNFG_02 0x18
+#define MAX77976_REG_CHG_CNFG_06 0x1c
+#define MAX77976_REG_CHG_CNFG_09 0x1f
+
+/* CHG_DETAILS_01.CHG_DTLS values */
+enum max77976_charging_state {
+ MAX77976_CHARGING_PREQUALIFICATION = 0x0,
+ MAX77976_CHARGING_FAST_CONST_CURRENT,
+ MAX77976_CHARGING_FAST_CONST_VOLTAGE,
+ MAX77976_CHARGING_TOP_OFF,
+ MAX77976_CHARGING_DONE,
+ MAX77976_CHARGING_RESERVED_05,
+ MAX77976_CHARGING_TIMER_FAULT,
+ MAX77976_CHARGING_SUSPENDED_QBATT_OFF,
+ MAX77976_CHARGING_OFF,
+ MAX77976_CHARGING_RESERVED_09,
+ MAX77976_CHARGING_THERMAL_SHUTDOWN,
+ MAX77976_CHARGING_WATCHDOG_EXPIRED,
+ MAX77976_CHARGING_SUSPENDED_JEITA,
+ MAX77976_CHARGING_SUSPENDED_THM_REMOVAL,
+ MAX77976_CHARGING_SUSPENDED_PIN,
+ MAX77976_CHARGING_RESERVED_0F,
+};
+
+/* CHG_DETAILS_01.BAT_DTLS values */
+enum max77976_battery_state {
+ MAX77976_BATTERY_BATTERY_REMOVAL = 0x0,
+ MAX77976_BATTERY_PREQUALIFICATION,
+ MAX77976_BATTERY_TIMER_FAULT,
+ MAX77976_BATTERY_REGULAR_VOLTAGE,
+ MAX77976_BATTERY_LOW_VOLTAGE,
+ MAX77976_BATTERY_OVERVOLTAGE,
+ MAX77976_BATTERY_RESERVED,
+ MAX77976_BATTERY_BATTERY_ONLY, // No valid adapter is present
+};
+
+/* CHG_CNFG_00.MODE values */
+enum max77976_mode {
+ MAX77976_MODE_CHARGER_BUCK = 0x5,
+ MAX77976_MODE_BOOST = 0x9,
+};
+
+/* CHG_CNFG_02.CHG_CC: charge current limit, 100..5500 mA, 50 mA steps */
+#define MAX77976_CHG_CC_STEP 50000U
+#define MAX77976_CHG_CC_MIN 100000U
+#define MAX77976_CHG_CC_MAX 5500000U
+
+/* CHG_CNFG_09.CHGIN_ILIM: input current limit, 100..3200 mA, 100 mA steps */
+#define MAX77976_CHGIN_ILIM_STEP 100000U
+#define MAX77976_CHGIN_ILIM_MIN 100000U
+#define MAX77976_CHGIN_ILIM_MAX 3200000U
+
+enum max77976_field_idx {
+ VERSION, REVISION, /* CHIP_REVISION */
+ CHGIN_OK, /* CHG_INT_OK */
+ BAT_DTLS, CHG_DTLS, /* CHG_DETAILS_01 */
+ MODE, /* CHG_CNFG_00 */
+ CHG_CC, /* CHG_CNFG_02 */
+ CHGPROT, /* CHG_CNFG_06 */
+ CHGIN_ILIM, /* CHG_CNFG_09 */
+ MAX77976_N_REGMAP_FIELDS
+};
+
+static const struct reg_field max77976_reg_field[MAX77976_N_REGMAP_FIELDS] = {
+ [VERSION] = REG_FIELD(MAX77976_REG_CHIP_REVISION, 4, 7),
+ [REVISION] = REG_FIELD(MAX77976_REG_CHIP_REVISION, 0, 3),
+ [CHGIN_OK] = REG_FIELD(MAX77976_REG_CHG_INT_OK, 6, 6),
+ [CHG_DTLS] = REG_FIELD(MAX77976_REG_CHG_DETAILS_01, 0, 3),
+ [BAT_DTLS] = REG_FIELD(MAX77976_REG_CHG_DETAILS_01, 4, 6),
+ [MODE] = REG_FIELD(MAX77976_REG_CHG_CNFG_00, 0, 3),
+ [CHG_CC] = REG_FIELD(MAX77976_REG_CHG_CNFG_02, 0, 6),
+ [CHGPROT] = REG_FIELD(MAX77976_REG_CHG_CNFG_06, 2, 3),
+ [CHGIN_ILIM] = REG_FIELD(MAX77976_REG_CHG_CNFG_09, 0, 5),
+};
+
+static const struct regmap_config max77976_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0x24,
+};
+
+/* --------------------------------------------------------------------------
+ * Data structures
+ */
+
+struct max77976 {
+ struct i2c_client *client;
+ struct regmap *regmap;
+ struct regmap_field *rfield[MAX77976_N_REGMAP_FIELDS];
+};
+
+/* --------------------------------------------------------------------------
+ * power_supply properties
+ */
+
+static int max77976_get_status(struct max77976 *chg, int *val)
+{
+ unsigned int regval;
+ int err;
+
+ err = regmap_field_read(chg->rfield[CHG_DTLS], ®val);
+ if (err < 0)
+ return err;
+
+ switch (regval) {
+ case MAX77976_CHARGING_PREQUALIFICATION:
+ case MAX77976_CHARGING_FAST_CONST_CURRENT:
+ case MAX77976_CHARGING_FAST_CONST_VOLTAGE:
+ case MAX77976_CHARGING_TOP_OFF:
+ *val = POWER_SUPPLY_STATUS_CHARGING;
+ break;
+ case MAX77976_CHARGING_DONE:
+ *val = POWER_SUPPLY_STATUS_FULL;
+ break;
+ case MAX77976_CHARGING_TIMER_FAULT:
+ case MAX77976_CHARGING_SUSPENDED_QBATT_OFF:
+ case MAX77976_CHARGING_SUSPENDED_JEITA:
+ case MAX77976_CHARGING_SUSPENDED_THM_REMOVAL:
+ case MAX77976_CHARGING_SUSPENDED_PIN:
+ *val = POWER_SUPPLY_STATUS_NOT_CHARGING;
+ break;
+ case MAX77976_CHARGING_OFF:
+ case MAX77976_CHARGING_THERMAL_SHUTDOWN:
+ case MAX77976_CHARGING_WATCHDOG_EXPIRED:
+ *val = POWER_SUPPLY_STATUS_DISCHARGING;
+ break;
+ default:
+ *val = POWER_SUPPLY_STATUS_UNKNOWN;
+ }
+
+ return 0;
+}
+
+static int max77976_get_charge_type(struct max77976 *chg, int *val)
+{
+ unsigned int regval;
+ int err;
+
+ err = regmap_field_read(chg->rfield[CHG_DTLS], ®val);
+ if (err < 0)
+ return err;
+
+ switch (regval) {
+ case MAX77976_CHARGING_PREQUALIFICATION:
+ *val = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+ break;
+ case MAX77976_CHARGING_FAST_CONST_CURRENT:
+ case MAX77976_CHARGING_FAST_CONST_VOLTAGE:
+ *val = POWER_SUPPLY_CHARGE_TYPE_FAST;
+ break;
+ case MAX77976_CHARGING_TOP_OFF:
+ *val = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
+ break;
+ case MAX77976_CHARGING_DONE:
+ case MAX77976_CHARGING_TIMER_FAULT:
+ case MAX77976_CHARGING_SUSPENDED_QBATT_OFF:
+ case MAX77976_CHARGING_OFF:
+ case MAX77976_CHARGING_THERMAL_SHUTDOWN:
+ case MAX77976_CHARGING_WATCHDOG_EXPIRED:
+ case MAX77976_CHARGING_SUSPENDED_JEITA:
+ case MAX77976_CHARGING_SUSPENDED_THM_REMOVAL:
+ case MAX77976_CHARGING_SUSPENDED_PIN:
+ *val = POWER_SUPPLY_CHARGE_TYPE_NONE;
+ break;
+ default:
+ *val = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+ }
+
+ return 0;
+}
+
+static int max77976_get_health(struct max77976 *chg, int *val)
+{
+ unsigned int regval;
+ int err;
+
+ err = regmap_field_read(chg->rfield[BAT_DTLS], ®val);
+ if (err < 0)
+ return err;
+
+ switch (regval) {
+ case MAX77976_BATTERY_BATTERY_REMOVAL:
+ *val = POWER_SUPPLY_HEALTH_NO_BATTERY;
+ break;
+ case MAX77976_BATTERY_LOW_VOLTAGE:
+ case MAX77976_BATTERY_REGULAR_VOLTAGE:
+ *val = POWER_SUPPLY_HEALTH_GOOD;
+ break;
+ case MAX77976_BATTERY_TIMER_FAULT:
+ *val = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+ break;
+ case MAX77976_BATTERY_OVERVOLTAGE:
+ *val = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+ break;
+ case MAX77976_BATTERY_PREQUALIFICATION:
+ case MAX77976_BATTERY_BATTERY_ONLY:
+ *val = POWER_SUPPLY_HEALTH_UNKNOWN;
+ break;
+ default:
+ *val = POWER_SUPPLY_HEALTH_UNKNOWN;
+ }
+
+ return 0;
+}
+
+static int max77976_get_online(struct max77976 *chg, int *val)
+{
+ unsigned int regval;
+ int err;
+
+ err = regmap_field_read(chg->rfield[CHGIN_OK], ®val);
+ if (err < 0)
+ return err;
+
+ *val = (regval ? 1 : 0);
+
+ return 0;
+}
+
+static int max77976_get_integer(struct max77976 *chg, enum max77976_field_idx fidx,
+ unsigned int clamp_min, unsigned int clamp_max,
+ unsigned int mult, int *val)
+{
+ unsigned int regval;
+ int err;
+
+ err = regmap_field_read(chg->rfield[fidx], ®val);
+ if (err < 0)
+ return err;
+
+ *val = clamp_val(regval * mult, clamp_min, clamp_max);
+
+ return 0;
+}
+
+static int max77976_set_integer(struct max77976 *chg, enum max77976_field_idx fidx,
+ unsigned int clamp_min, unsigned int clamp_max,
+ unsigned int div, int val)
+{
+ unsigned int regval;
+
+ regval = clamp_val(val, clamp_min, clamp_max) / div;
+
+ return regmap_field_write(chg->rfield[fidx], regval);
+}
+
+static int max77976_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct max77976 *chg = power_supply_get_drvdata(psy);
+ int err = 0;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ err = max77976_get_status(chg, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ err = max77976_get_charge_type(chg, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_HEALTH:
+ err = max77976_get_health(chg, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_ONLINE:
+ err = max77976_get_online(chg, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
+ val->intval = MAX77976_CHG_CC_MAX;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+ err = max77976_get_integer(chg, CHG_CC,
+ MAX77976_CHG_CC_MIN,
+ MAX77976_CHG_CC_MAX,
+ MAX77976_CHG_CC_STEP,
+ &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ err = max77976_get_integer(chg, CHGIN_ILIM,
+ MAX77976_CHGIN_ILIM_MIN,
+ MAX77976_CHGIN_ILIM_MAX,
+ MAX77976_CHGIN_ILIM_STEP,
+ &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_MODEL_NAME:
+ val->strval = max77976_model;
+ break;
+ case POWER_SUPPLY_PROP_MANUFACTURER:
+ val->strval = max77976_manufacturer;
+ break;
+ default:
+ err = -EINVAL;
+ }
+
+ return err;
+}
+
+static int max77976_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct max77976 *chg = power_supply_get_drvdata(psy);
+ int err = 0;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+ err = max77976_set_integer(chg, CHG_CC,
+ MAX77976_CHG_CC_MIN,
+ MAX77976_CHG_CC_MAX,
+ MAX77976_CHG_CC_STEP,
+ val->intval);
+ break;
+ case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+ err = max77976_set_integer(chg, CHGIN_ILIM,
+ MAX77976_CHGIN_ILIM_MIN,
+ MAX77976_CHGIN_ILIM_MAX,
+ MAX77976_CHGIN_ILIM_STEP,
+ val->intval);
+ break;
+ default:
+ err = -EINVAL;
+ }
+
+ return err;
+};
+
+static int max77976_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 max77976_psy_props[] = {
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_CHARGE_TYPE,
+ POWER_SUPPLY_PROP_HEALTH,
+ POWER_SUPPLY_PROP_ONLINE,
+ 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 max77976_psy_desc = {
+ .name = MAX77976_DRIVER_NAME,
+ .type = POWER_SUPPLY_TYPE_USB,
+ .properties = max77976_psy_props,
+ .num_properties = ARRAY_SIZE(max77976_psy_props),
+ .get_property = max77976_get_property,
+ .set_property = max77976_set_property,
+ .property_is_writeable = max77976_property_is_writeable,
+};
+
+/* --------------------------------------------------------------------------
+ * Entry point
+ */
+
+static int max77976_detect(struct max77976 *chg)
+{
+ struct device *dev = &chg->client->dev;
+ unsigned int id, ver, rev;
+ int err;
+
+ err = regmap_read(chg->regmap, MAX77976_REG_CHIP_ID, &id);
+ if (err)
+ return dev_err_probe(dev, err, "cannot read chip ID\n");
+
+ if (id != MAX77976_CHIP_ID)
+ return dev_err_probe(dev, -ENXIO, "unknown model ID 0x%02x\n", id);
+
+ err = regmap_field_read(chg->rfield[VERSION], &ver);
+ if (!err)
+ err = regmap_field_read(chg->rfield[REVISION], &rev);
+ if (err)
+ return dev_err_probe(dev, -ENXIO, "cannot read version/revision\n");
+
+ dev_info(dev, "detected model MAX779%02x ver %u rev %u", id, ver, rev);
+
+ return 0;
+}
+
+static int max77976_configure(struct max77976 *chg)
+{
+ struct device *dev = &chg->client->dev;
+ int err;
+
+ /* Magic value to unlock writing to some registers */
+ err = regmap_field_write(chg->rfield[CHGPROT], 0x3);
+ if (err)
+ goto err;
+
+ /*
+ * Mode 5 = Charger ON, OTG OFF, buck ON, boost OFF.
+ * Other modes are not implemented by this driver.
+ */
+ err = regmap_field_write(chg->rfield[MODE], MAX77976_MODE_CHARGER_BUCK);
+ if (err)
+ goto err;
+
+ return 0;
+
+err:
+ return dev_err_probe(dev, err, "error while configuring");
+}
+
+static int max77976_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct power_supply_config psy_cfg = {};
+ struct power_supply *psy;
+ struct max77976 *chg;
+ int err;
+ int i;
+
+ chg = devm_kzalloc(dev, sizeof(*chg), GFP_KERNEL);
+ if (!chg)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, chg);
+ psy_cfg.drv_data = chg;
+ chg->client = client;
+
+ chg->regmap = devm_regmap_init_i2c(client, &max77976_regmap_config);
+ if (IS_ERR(chg->regmap))
+ return dev_err_probe(dev, PTR_ERR(chg->regmap),
+ "cannot allocate regmap\n");
+
+ for (i = 0; i < MAX77976_N_REGMAP_FIELDS; i++) {
+ chg->rfield[i] = devm_regmap_field_alloc(dev, chg->regmap,
+ max77976_reg_field[i]);
+ if (IS_ERR(chg->rfield[i]))
+ return dev_err_probe(dev, PTR_ERR(chg->rfield[i]),
+ "cannot allocate regmap field\n");
+ }
+
+ err = max77976_detect(chg);
+ if (err)
+ return err;
+
+ err = max77976_configure(chg);
+ if (err)
+ return err;
+
+ psy = devm_power_supply_register_no_ws(dev, &max77976_psy_desc, &psy_cfg);
+ if (IS_ERR(psy))
+ return dev_err_probe(dev, PTR_ERR(psy), "cannot register\n");
+
+ return 0;
+}
+
+static const struct i2c_device_id max77976_i2c_id[] = {
+ { MAX77976_DRIVER_NAME, 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, max77976_i2c_id);
+
+static const struct of_device_id max77976_of_id[] = {
+ { .compatible = "maxim,max77976" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, max77976_of_id);
+
+static struct i2c_driver max77976_driver = {
+ .driver = {
+ .name = MAX77976_DRIVER_NAME,
+ .of_match_table = max77976_of_id,
+ },
+ .probe_new = max77976_probe,
+ .id_table = max77976_i2c_id,
+};
+module_i2c_driver(max77976_driver);
+
+MODULE_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>");
+MODULE_DESCRIPTION("Maxim MAX77976 charger driver");
+MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-starfive.git / commitdiff