diff options
Diffstat (limited to 'drivers/power/supply/sbs-charger.c')
| -rw-r--r-- | drivers/power/supply/sbs-charger.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/power/supply/sbs-charger.c b/drivers/power/supply/sbs-charger.c new file mode 100644 index 000000000000..353765a5f44c --- /dev/null +++ b/drivers/power/supply/sbs-charger.c @@ -0,0 +1,274 @@ +/* + * Copyright (c) 2016, Prodys S.L. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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/gpio.h> +#include <linux/regmap.h> +#include <linux/of_gpio.h> +#include <linux/bitops.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) +{ + if (reg < SBS_CHARGER_REG_SPEC_INFO) + return false; + else + return true; +} + +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, + const struct i2c_device_id *id) +{ + 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) { + dev_err(&client->dev, "Failed to get device status\n"); + return ret; + } + chip->last_state = val; + + chip->power_supply = devm_power_supply_register(&client->dev, &sbs_desc, + &psy_cfg); + if (IS_ERR(chip->power_supply)) { + dev_err(&client->dev, "Failed to register power supply\n"); + return PTR_ERR(chip->power_supply); + } + + /* + * 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) { + dev_err(&client->dev, "Failed to request irq, %d\n", ret); + return ret; + } + } else { + INIT_DELAYED_WORK(&chip->work, sbs_delayed_work); + 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; +} + +static int sbs_remove(struct i2c_client *client) +{ + struct sbs_info *chip = i2c_get_clientdata(client); + + cancel_delayed_work_sync(&chip->work); + + 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 = sbs_probe, + .remove = sbs_remove, + .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"); |