| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (c) 2016, Prodys S.L. |
| * |
| * This adds support for sbs-charger compilant chips as defined here: |
| * http://sbs-forum.org/specs/sbc110.pdf |
| * |
| * Implemetation based on sbs-battery.c |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/err.h> |
| #include <linux/power_supply.h> |
| #include <linux/i2c.h> |
| #include <linux/slab.h> |
| #include <linux/interrupt.h> |
| #include <linux/regmap.h> |
| #include <linux/bitops.h> |
| #include <linux/devm-helpers.h> |
| |
| #define SBS_CHARGER_REG_SPEC_INFO 0x11 |
| #define SBS_CHARGER_REG_STATUS 0x13 |
| #define SBS_CHARGER_REG_ALARM_WARNING 0x16 |
| |
| #define SBS_CHARGER_STATUS_CHARGE_INHIBITED BIT(1) |
| #define SBS_CHARGER_STATUS_RES_COLD BIT(9) |
| #define SBS_CHARGER_STATUS_RES_HOT BIT(10) |
| #define SBS_CHARGER_STATUS_BATTERY_PRESENT BIT(14) |
| #define SBS_CHARGER_STATUS_AC_PRESENT BIT(15) |
| |
| #define SBS_CHARGER_POLL_TIME 500 |
| |
| struct sbs_info { |
| struct i2c_client *client; |
| struct power_supply *power_supply; |
| struct regmap *regmap; |
| struct delayed_work work; |
| unsigned int last_state; |
| }; |
| |
| static int sbs_get_property(struct power_supply *psy, |
| enum power_supply_property psp, |
| union power_supply_propval *val) |
| { |
| struct sbs_info *chip = power_supply_get_drvdata(psy); |
| unsigned int reg; |
| |
| reg = chip->last_state; |
| |
| switch (psp) { |
| case POWER_SUPPLY_PROP_PRESENT: |
| val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT); |
| break; |
| |
| case POWER_SUPPLY_PROP_ONLINE: |
| val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT); |
| break; |
| |
| case POWER_SUPPLY_PROP_STATUS: |
| val->intval = POWER_SUPPLY_STATUS_UNKNOWN; |
| |
| if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT)) |
| val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; |
| else if (reg & SBS_CHARGER_STATUS_AC_PRESENT && |
| !(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED)) |
| val->intval = POWER_SUPPLY_STATUS_CHARGING; |
| else |
| val->intval = POWER_SUPPLY_STATUS_DISCHARGING; |
| |
| break; |
| |
| case POWER_SUPPLY_PROP_HEALTH: |
| if (reg & SBS_CHARGER_STATUS_RES_COLD) |
| val->intval = POWER_SUPPLY_HEALTH_COLD; |
| if (reg & SBS_CHARGER_STATUS_RES_HOT) |
| val->intval = POWER_SUPPLY_HEALTH_OVERHEAT; |
| else |
| val->intval = POWER_SUPPLY_HEALTH_GOOD; |
| |
| break; |
| |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int sbs_check_state(struct sbs_info *chip) |
| { |
| unsigned int reg; |
| int ret; |
| |
| ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, ®); |
| if (!ret && reg != chip->last_state) { |
| chip->last_state = reg; |
| power_supply_changed(chip->power_supply); |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| static void sbs_delayed_work(struct work_struct *work) |
| { |
| struct sbs_info *chip = container_of(work, struct sbs_info, work.work); |
| |
| sbs_check_state(chip); |
| |
| schedule_delayed_work(&chip->work, |
| msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); |
| } |
| |
| static irqreturn_t sbs_irq_thread(int irq, void *data) |
| { |
| struct sbs_info *chip = data; |
| int ret; |
| |
| ret = sbs_check_state(chip); |
| |
| return ret ? IRQ_HANDLED : IRQ_NONE; |
| } |
| |
| static enum power_supply_property sbs_properties[] = { |
| POWER_SUPPLY_PROP_STATUS, |
| POWER_SUPPLY_PROP_PRESENT, |
| POWER_SUPPLY_PROP_ONLINE, |
| POWER_SUPPLY_PROP_HEALTH, |
| }; |
| |
| static bool sbs_readable_reg(struct device *dev, unsigned int reg) |
| { |
| return reg >= SBS_CHARGER_REG_SPEC_INFO; |
| } |
| |
| static bool sbs_volatile_reg(struct device *dev, unsigned int reg) |
| { |
| switch (reg) { |
| case SBS_CHARGER_REG_STATUS: |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static const struct regmap_config sbs_regmap = { |
| .reg_bits = 8, |
| .val_bits = 16, |
| .max_register = SBS_CHARGER_REG_ALARM_WARNING, |
| .readable_reg = sbs_readable_reg, |
| .volatile_reg = sbs_volatile_reg, |
| .val_format_endian = REGMAP_ENDIAN_LITTLE, /* since based on SMBus */ |
| }; |
| |
| static const struct power_supply_desc sbs_desc = { |
| .name = "sbs-charger", |
| .type = POWER_SUPPLY_TYPE_MAINS, |
| .properties = sbs_properties, |
| .num_properties = ARRAY_SIZE(sbs_properties), |
| .get_property = sbs_get_property, |
| }; |
| |
| static int sbs_probe(struct i2c_client *client) |
| { |
| struct power_supply_config psy_cfg = {}; |
| struct sbs_info *chip; |
| int ret, val; |
| |
| chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL); |
| if (!chip) |
| return -ENOMEM; |
| |
| chip->client = client; |
| psy_cfg.of_node = client->dev.of_node; |
| psy_cfg.drv_data = chip; |
| |
| i2c_set_clientdata(client, chip); |
| |
| chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap); |
| if (IS_ERR(chip->regmap)) |
| return PTR_ERR(chip->regmap); |
| |
| /* |
| * Before we register, we need to make sure we can actually talk |
| * to the battery. |
| */ |
| ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &val); |
| if (ret) |
| return dev_err_probe(&client->dev, ret, "Failed to get device status\n"); |
| chip->last_state = val; |
| |
| chip->power_supply = devm_power_supply_register(&client->dev, &sbs_desc, &psy_cfg); |
| if (IS_ERR(chip->power_supply)) |
| return dev_err_probe(&client->dev, PTR_ERR(chip->power_supply), |
| "Failed to register power supply\n"); |
| |
| /* |
| * The sbs-charger spec doesn't impose the use of an interrupt. So in |
| * the case it wasn't provided we use polling in order get the charger's |
| * status. |
| */ |
| if (client->irq) { |
| ret = devm_request_threaded_irq(&client->dev, client->irq, |
| NULL, sbs_irq_thread, |
| IRQF_TRIGGER_FALLING | IRQF_ONESHOT, |
| dev_name(&client->dev), chip); |
| if (ret) |
| return dev_err_probe(&client->dev, ret, "Failed to request irq\n"); |
| } else { |
| ret = devm_delayed_work_autocancel(&client->dev, &chip->work, |
| sbs_delayed_work); |
| if (ret) |
| return dev_err_probe(&client->dev, ret, |
| "Failed to init work for polling\n"); |
| |
| schedule_delayed_work(&chip->work, |
| msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); |
| } |
| |
| dev_info(&client->dev, |
| "%s: smart charger device registered\n", client->name); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_OF |
| static const struct of_device_id sbs_dt_ids[] = { |
| { .compatible = "sbs,sbs-charger" }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(of, sbs_dt_ids); |
| #endif |
| |
| static const struct i2c_device_id sbs_id[] = { |
| { "sbs-charger", 0 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, sbs_id); |
| |
| static struct i2c_driver sbs_driver = { |
| .probe_new = sbs_probe, |
| .id_table = sbs_id, |
| .driver = { |
| .name = "sbs-charger", |
| .of_match_table = of_match_ptr(sbs_dt_ids), |
| }, |
| }; |
| module_i2c_driver(sbs_driver); |
| |
| MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>"); |
| MODULE_DESCRIPTION("SBS smart charger driver"); |
| MODULE_LICENSE("GPL v2"); |