root/drivers/power/supply/bq27xxx_battery_i2c.c
// SPDX-License-Identifier: GPL-2.0
/*
 * BQ27xxx battery monitor I2C driver
 *
 * Copyright (C) 2015 Texas Instruments Incorporated - https://www.ti.com/
 *      Andrew F. Davis <afd@ti.com>
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/unaligned.h>

#include <linux/power/bq27xxx_battery.h>

static DEFINE_IDA(battery_id);

static irqreturn_t bq27xxx_battery_irq_handler_thread(int irq, void *data)
{
        struct bq27xxx_device_info *di = data;

        bq27xxx_battery_update(di);

        return IRQ_HANDLED;
}

static int bq27xxx_battery_i2c_read(struct bq27xxx_device_info *di, u8 reg,
                                    bool single)
{
        struct i2c_client *client = to_i2c_client(di->dev);
        struct i2c_msg msg[2];
        u8 data[2];
        int ret;
        int retry = 0;

        if (!client->adapter)
                return -ENODEV;

        msg[0].addr = client->addr;
        msg[0].flags = 0;
        msg[0].buf = &reg;
        msg[0].len = sizeof(reg);
        msg[1].addr = client->addr;
        msg[1].flags = I2C_M_RD;
        msg[1].buf = data;
        if (single)
                msg[1].len = 1;
        else
                msg[1].len = 2;

        do {
                ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
                if (ret == -EBUSY && ++retry < 3) {
                        /* sleep 10 milliseconds when busy */
                        usleep_range(10000, 11000);
                        continue;
                }
                break;
        } while (1);

        if (ret < 0)
                return ret;

        if (!single)
                ret = get_unaligned_le16(data);
        else
                ret = data[0];

        return ret;
}

static int bq27xxx_battery_i2c_write(struct bq27xxx_device_info *di, u8 reg,
                                     int value, bool single)
{
        struct i2c_client *client = to_i2c_client(di->dev);
        struct i2c_msg msg;
        u8 data[4];
        int ret;

        if (!client->adapter)
                return -ENODEV;

        data[0] = reg;
        if (single) {
                data[1] = (u8) value;
                msg.len = 2;
        } else {
                put_unaligned_le16(value, &data[1]);
                msg.len = 3;
        }

        msg.buf = data;
        msg.addr = client->addr;
        msg.flags = 0;

        ret = i2c_transfer(client->adapter, &msg, 1);
        if (ret < 0)
                return ret;
        if (ret != 1)
                return -EINVAL;
        return 0;
}

static int bq27xxx_battery_i2c_bulk_read(struct bq27xxx_device_info *di, u8 reg,
                                         u8 *data, int len)
{
        struct i2c_client *client = to_i2c_client(di->dev);
        int ret;

        if (!client->adapter)
                return -ENODEV;

        ret = i2c_smbus_read_i2c_block_data(client, reg, len, data);
        if (ret < 0)
                return ret;
        if (ret != len)
                return -EINVAL;
        return 0;
}

static int bq27xxx_battery_i2c_bulk_write(struct bq27xxx_device_info *di,
                                          u8 reg, u8 *data, int len)
{
        struct i2c_client *client = to_i2c_client(di->dev);
        struct i2c_msg msg;
        u8 buf[33];
        int ret;

        if (!client->adapter)
                return -ENODEV;

        buf[0] = reg;
        memcpy(&buf[1], data, len);

        msg.buf = buf;
        msg.addr = client->addr;
        msg.flags = 0;
        msg.len = len + 1;

        ret = i2c_transfer(client->adapter, &msg, 1);
        if (ret < 0)
                return ret;
        if (ret != 1)
                return -EINVAL;
        return 0;
}

static void bq27xxx_battery_i2c_devm_ida_free(void *data)
{
        int num = (long)data;

        ida_free(&battery_id, num);
}

static int bq27xxx_battery_i2c_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        struct bq27xxx_device_info *di;
        int ret;
        char *name;
        long num;

        /* Get new ID for the new battery device */
        num = ida_alloc(&battery_id, GFP_KERNEL);
        if (num < 0)
                return num;
        ret = devm_add_action_or_reset(&client->dev,
                                       bq27xxx_battery_i2c_devm_ida_free,
                                       (void *)num);
        if (ret)
                return ret;

        name = devm_kasprintf(&client->dev, GFP_KERNEL, "%s-%ld", id->name, num);
        if (!name)
                return -ENOMEM;

        di = devm_kzalloc(&client->dev, sizeof(*di), GFP_KERNEL);
        if (!di)
                return -ENOMEM;

        di->dev = &client->dev;
        di->chip = id->driver_data;
        di->name = name;

        di->bus.read = bq27xxx_battery_i2c_read;
        di->bus.write = bq27xxx_battery_i2c_write;
        di->bus.read_bulk = bq27xxx_battery_i2c_bulk_read;
        di->bus.write_bulk = bq27xxx_battery_i2c_bulk_write;

        ret = bq27xxx_battery_setup(di);
        if (ret)
                return ret;

        /* Schedule a polling after about 1 min */
        schedule_delayed_work(&di->work, 60 * HZ);

        i2c_set_clientdata(client, di);

        if (client->irq) {
                ret = request_threaded_irq(client->irq,
                                NULL, bq27xxx_battery_irq_handler_thread,
                                IRQF_ONESHOT,
                                di->name, di);
                if (ret) {
                        dev_err(&client->dev,
                                "Unable to register IRQ %d error %d\n",
                                client->irq, ret);
                        bq27xxx_battery_teardown(di);
                        return ret;
                }
        }

        return 0;
}

static void bq27xxx_battery_i2c_remove(struct i2c_client *client)
{
        struct bq27xxx_device_info *di = i2c_get_clientdata(client);

        if (client->irq)
                free_irq(client->irq, di);

        bq27xxx_battery_teardown(di);
}

static const struct i2c_device_id bq27xxx_i2c_id_table[] = {
        { "bq27200", BQ27000 },
        { "bq27210", BQ27010 },
        { "bq27500", BQ2750X },
        { "bq27510", BQ2751X },
        { "bq27520", BQ2752X },
        { "bq27500-1", BQ27500 },
        { "bq27510g1", BQ27510G1 },
        { "bq27510g2", BQ27510G2 },
        { "bq27510g3", BQ27510G3 },
        { "bq27520g1", BQ27520G1 },
        { "bq27520g2", BQ27520G2 },
        { "bq27520g3", BQ27520G3 },
        { "bq27520g4", BQ27520G4 },
        { "bq27521", BQ27521 },
        { "bq27530", BQ27530 },
        { "bq27531", BQ27531 },
        { "bq27541", BQ27541 },
        { "bq27542", BQ27542 },
        { "bq27546", BQ27546 },
        { "bq27742", BQ27742 },
        { "bq27545", BQ27545 },
        { "bq27411", BQ27411 },
        { "bq27421", BQ27421 },
        { "bq27425", BQ27425 },
        { "bq27426", BQ27426 },
        { "bq27441", BQ27441 },
        { "bq27621", BQ27621 },
        { "bq27z561", BQ27Z561 },
        { "bq28z610", BQ28Z610 },
        { "bq34z100", BQ34Z100 },
        { "bq78z100", BQ78Z100 },
        {},
};
MODULE_DEVICE_TABLE(i2c, bq27xxx_i2c_id_table);

#ifdef CONFIG_OF
static const struct of_device_id bq27xxx_battery_i2c_of_match_table[] = {
        { .compatible = "ti,bq27200" },
        { .compatible = "ti,bq27210" },
        { .compatible = "ti,bq27500" },
        { .compatible = "ti,bq27510" },
        { .compatible = "ti,bq27520" },
        { .compatible = "ti,bq27500-1" },
        { .compatible = "ti,bq27510g1" },
        { .compatible = "ti,bq27510g2" },
        { .compatible = "ti,bq27510g3" },
        { .compatible = "ti,bq27520g1" },
        { .compatible = "ti,bq27520g2" },
        { .compatible = "ti,bq27520g3" },
        { .compatible = "ti,bq27520g4" },
        { .compatible = "ti,bq27521" },
        { .compatible = "ti,bq27530" },
        { .compatible = "ti,bq27531" },
        { .compatible = "ti,bq27541" },
        { .compatible = "ti,bq27542" },
        { .compatible = "ti,bq27546" },
        { .compatible = "ti,bq27742" },
        { .compatible = "ti,bq27545" },
        { .compatible = "ti,bq27411" },
        { .compatible = "ti,bq27421" },
        { .compatible = "ti,bq27425" },
        { .compatible = "ti,bq27426" },
        { .compatible = "ti,bq27441" },
        { .compatible = "ti,bq27621" },
        { .compatible = "ti,bq27z561" },
        { .compatible = "ti,bq28z610" },
        { .compatible = "ti,bq34z100" },
        { .compatible = "ti,bq78z100" },
        {},
};
MODULE_DEVICE_TABLE(of, bq27xxx_battery_i2c_of_match_table);
#endif

static struct i2c_driver bq27xxx_battery_i2c_driver = {
        .driver = {
                .name = "bq27xxx-battery",
                .of_match_table = of_match_ptr(bq27xxx_battery_i2c_of_match_table),
                .pm = &bq27xxx_battery_battery_pm_ops,
        },
        .probe = bq27xxx_battery_i2c_probe,
        .remove = bq27xxx_battery_i2c_remove,
        .id_table = bq27xxx_i2c_id_table,
};
module_i2c_driver(bq27xxx_battery_i2c_driver);

MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_DESCRIPTION("BQ27xxx battery monitor i2c driver");
MODULE_LICENSE("GPL");