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1// SPDX-License-Identifier: GPL-2.02/*3 * BQ27xxx battery monitor HDQ/1-wire driver4 *5 * Copyright (C) 2007-2017 Texas Instruments Incorporated - https://www.ti.com/6 *7 */8 9#include <linux/kernel.h>10#include <linux/module.h>11#include <linux/device.h>12#include <linux/types.h>13#include <linux/platform_device.h>14#include <linux/mutex.h>15#include <linux/power/bq27xxx_battery.h>16 17#include <linux/w1.h>18 19#define W1_FAMILY_BQ27000 0x0120 21#define HDQ_CMD_READ (0 << 7)22#define HDQ_CMD_WRITE (1 << 7)23 24static int F_ID;25module_param(F_ID, int, S_IRUSR);26MODULE_PARM_DESC(F_ID, "1-wire slave FID for BQ27xxx device");27 28static int w1_bq27000_read(struct w1_slave *sl, unsigned int reg)29{30 u8 val;31 32 mutex_lock(&sl->master->bus_mutex);33 w1_write_8(sl->master, HDQ_CMD_READ | reg);34 val = w1_read_8(sl->master);35 mutex_unlock(&sl->master->bus_mutex);36 37 return val;38}39 40static int bq27xxx_battery_hdq_read(struct bq27xxx_device_info *di, u8 reg,41 bool single)42{43 struct w1_slave *sl = dev_to_w1_slave(di->dev);44 unsigned int timeout = 3;45 int upper, lower;46 int temp;47 48 if (!single) {49 /*50 * Make sure the value has not changed in between reading the51 * lower and the upper part52 */53 upper = w1_bq27000_read(sl, reg + 1);54 do {55 temp = upper;56 if (upper < 0)57 return upper;58 59 lower = w1_bq27000_read(sl, reg);60 if (lower < 0)61 return lower;62 63 upper = w1_bq27000_read(sl, reg + 1);64 } while (temp != upper && --timeout);65 66 if (timeout == 0)67 return -EIO;68 69 return (upper << 8) | lower;70 }71 72 return w1_bq27000_read(sl, reg);73}74 75static int bq27xxx_battery_hdq_add_slave(struct w1_slave *sl)76{77 struct bq27xxx_device_info *di;78 79 di = devm_kzalloc(&sl->dev, sizeof(*di), GFP_KERNEL);80 if (!di)81 return -ENOMEM;82 83 dev_set_drvdata(&sl->dev, di);84 85 di->dev = &sl->dev;86 di->chip = BQ27000;87 di->name = "bq27000-battery";88 di->bus.read = bq27xxx_battery_hdq_read;89 90 return bq27xxx_battery_setup(di);91}92 93static void bq27xxx_battery_hdq_remove_slave(struct w1_slave *sl)94{95 struct bq27xxx_device_info *di = dev_get_drvdata(&sl->dev);96 97 bq27xxx_battery_teardown(di);98}99 100static const struct w1_family_ops bq27xxx_battery_hdq_fops = {101 .add_slave = bq27xxx_battery_hdq_add_slave,102 .remove_slave = bq27xxx_battery_hdq_remove_slave,103};104 105static struct w1_family bq27xxx_battery_hdq_family = {106 .fid = W1_FAMILY_BQ27000,107 .fops = &bq27xxx_battery_hdq_fops,108};109 110static int __init bq27xxx_battery_hdq_init(void)111{112 if (F_ID)113 bq27xxx_battery_hdq_family.fid = F_ID;114 115 return w1_register_family(&bq27xxx_battery_hdq_family);116}117module_init(bq27xxx_battery_hdq_init);118 119static void __exit bq27xxx_battery_hdq_exit(void)120{121 w1_unregister_family(&bq27xxx_battery_hdq_family);122}123module_exit(bq27xxx_battery_hdq_exit);124 125MODULE_AUTHOR("Texas Instruments Ltd");126MODULE_DESCRIPTION("BQ27xxx battery monitor HDQ/1-wire driver");127MODULE_LICENSE("GPL");128MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_BQ27000));129