// SPDX-License-Identifier: GPL-2.0 /* * BQ27xxx battery monitor HDQ/1-wire driver * * Copyright (C) 2007-2017 Texas Instruments Incorporated - https://www.ti.com/ * */ #include #include #include #include #include #include #include #include #define W1_FAMILY_BQ27000 0x01 #define HDQ_CMD_READ (0 << 7) #define HDQ_CMD_WRITE (1 << 7) static int F_ID; module_param(F_ID, int, S_IRUSR); MODULE_PARM_DESC(F_ID, "1-wire slave FID for BQ27xxx device"); static int w1_bq27000_read(struct w1_slave *sl, unsigned int reg) { u8 val; mutex_lock(&sl->master->bus_mutex); w1_write_8(sl->master, HDQ_CMD_READ | reg); val = w1_read_8(sl->master); mutex_unlock(&sl->master->bus_mutex); return val; } static int bq27xxx_battery_hdq_read(struct bq27xxx_device_info *di, u8 reg, bool single) { struct w1_slave *sl = dev_to_w1_slave(di->dev); unsigned int timeout = 3; int upper, lower; int temp; if (!single) { /* * Make sure the value has not changed in between reading the * lower and the upper part */ upper = w1_bq27000_read(sl, reg + 1); do { temp = upper; if (upper < 0) return upper; lower = w1_bq27000_read(sl, reg); if (lower < 0) return lower; upper = w1_bq27000_read(sl, reg + 1); } while (temp != upper && --timeout); if (timeout == 0) return -EIO; return (upper << 8) | lower; } return w1_bq27000_read(sl, reg); } static int bq27xxx_battery_hdq_add_slave(struct w1_slave *sl) { struct bq27xxx_device_info *di; di = devm_kzalloc(&sl->dev, sizeof(*di), GFP_KERNEL); if (!di) return -ENOMEM; dev_set_drvdata(&sl->dev, di); di->dev = &sl->dev; di->chip = BQ27000; di->name = "bq27000-battery"; di->bus.read = bq27xxx_battery_hdq_read; return bq27xxx_battery_setup(di); } static void bq27xxx_battery_hdq_remove_slave(struct w1_slave *sl) { struct bq27xxx_device_info *di = dev_get_drvdata(&sl->dev); bq27xxx_battery_teardown(di); } static const struct w1_family_ops bq27xxx_battery_hdq_fops = { .add_slave = bq27xxx_battery_hdq_add_slave, .remove_slave = bq27xxx_battery_hdq_remove_slave, }; static struct w1_family bq27xxx_battery_hdq_family = { .fid = W1_FAMILY_BQ27000, .fops = &bq27xxx_battery_hdq_fops, }; static int __init bq27xxx_battery_hdq_init(void) { if (F_ID) bq27xxx_battery_hdq_family.fid = F_ID; return w1_register_family(&bq27xxx_battery_hdq_family); } module_init(bq27xxx_battery_hdq_init); static void __exit bq27xxx_battery_hdq_exit(void) { w1_unregister_family(&bq27xxx_battery_hdq_family); } module_exit(bq27xxx_battery_hdq_exit); MODULE_AUTHOR("Texas Instruments Ltd"); MODULE_DESCRIPTION("BQ27xxx battery monitor HDQ/1-wire driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_BQ27000));