1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * BQ27xxx battery monitor HDQ/1-wire driver
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2007-2017 Texas Instruments Incorporated - https://www.ti.com/
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/kernel.h>
10*4882a593Smuzhiyun #include <linux/module.h>
11*4882a593Smuzhiyun #include <linux/device.h>
12*4882a593Smuzhiyun #include <linux/types.h>
13*4882a593Smuzhiyun #include <linux/platform_device.h>
14*4882a593Smuzhiyun #include <linux/mutex.h>
15*4882a593Smuzhiyun #include <linux/power/bq27xxx_battery.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun #include <linux/w1.h>
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun #define W1_FAMILY_BQ27000 0x01
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #define HDQ_CMD_READ (0 << 7)
22*4882a593Smuzhiyun #define HDQ_CMD_WRITE (1 << 7)
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun static int F_ID;
25*4882a593Smuzhiyun module_param(F_ID, int, S_IRUSR);
26*4882a593Smuzhiyun MODULE_PARM_DESC(F_ID, "1-wire slave FID for BQ27xxx device");
27*4882a593Smuzhiyun
w1_bq27000_read(struct w1_slave * sl,unsigned int reg)28*4882a593Smuzhiyun static int w1_bq27000_read(struct w1_slave *sl, unsigned int reg)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun u8 val;
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun mutex_lock(&sl->master->bus_mutex);
33*4882a593Smuzhiyun w1_write_8(sl->master, HDQ_CMD_READ | reg);
34*4882a593Smuzhiyun val = w1_read_8(sl->master);
35*4882a593Smuzhiyun mutex_unlock(&sl->master->bus_mutex);
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun return val;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun
bq27xxx_battery_hdq_read(struct bq27xxx_device_info * di,u8 reg,bool single)40*4882a593Smuzhiyun static int bq27xxx_battery_hdq_read(struct bq27xxx_device_info *di, u8 reg,
41*4882a593Smuzhiyun bool single)
42*4882a593Smuzhiyun {
43*4882a593Smuzhiyun struct w1_slave *sl = dev_to_w1_slave(di->dev);
44*4882a593Smuzhiyun unsigned int timeout = 3;
45*4882a593Smuzhiyun int upper, lower;
46*4882a593Smuzhiyun int temp;
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun if (!single) {
49*4882a593Smuzhiyun /*
50*4882a593Smuzhiyun * Make sure the value has not changed in between reading the
51*4882a593Smuzhiyun * lower and the upper part
52*4882a593Smuzhiyun */
53*4882a593Smuzhiyun upper = w1_bq27000_read(sl, reg + 1);
54*4882a593Smuzhiyun do {
55*4882a593Smuzhiyun temp = upper;
56*4882a593Smuzhiyun if (upper < 0)
57*4882a593Smuzhiyun return upper;
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun lower = w1_bq27000_read(sl, reg);
60*4882a593Smuzhiyun if (lower < 0)
61*4882a593Smuzhiyun return lower;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun upper = w1_bq27000_read(sl, reg + 1);
64*4882a593Smuzhiyun } while (temp != upper && --timeout);
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun if (timeout == 0)
67*4882a593Smuzhiyun return -EIO;
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun return (upper << 8) | lower;
70*4882a593Smuzhiyun }
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun return w1_bq27000_read(sl, reg);
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun
bq27xxx_battery_hdq_add_slave(struct w1_slave * sl)75*4882a593Smuzhiyun static int bq27xxx_battery_hdq_add_slave(struct w1_slave *sl)
76*4882a593Smuzhiyun {
77*4882a593Smuzhiyun struct bq27xxx_device_info *di;
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun di = devm_kzalloc(&sl->dev, sizeof(*di), GFP_KERNEL);
80*4882a593Smuzhiyun if (!di)
81*4882a593Smuzhiyun return -ENOMEM;
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun dev_set_drvdata(&sl->dev, di);
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun di->dev = &sl->dev;
86*4882a593Smuzhiyun di->chip = BQ27000;
87*4882a593Smuzhiyun di->name = "bq27000-battery";
88*4882a593Smuzhiyun di->bus.read = bq27xxx_battery_hdq_read;
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun return bq27xxx_battery_setup(di);
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun
bq27xxx_battery_hdq_remove_slave(struct w1_slave * sl)93*4882a593Smuzhiyun static void bq27xxx_battery_hdq_remove_slave(struct w1_slave *sl)
94*4882a593Smuzhiyun {
95*4882a593Smuzhiyun struct bq27xxx_device_info *di = dev_get_drvdata(&sl->dev);
96*4882a593Smuzhiyun
97*4882a593Smuzhiyun bq27xxx_battery_teardown(di);
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun static const struct w1_family_ops bq27xxx_battery_hdq_fops = {
101*4882a593Smuzhiyun .add_slave = bq27xxx_battery_hdq_add_slave,
102*4882a593Smuzhiyun .remove_slave = bq27xxx_battery_hdq_remove_slave,
103*4882a593Smuzhiyun };
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun static struct w1_family bq27xxx_battery_hdq_family = {
106*4882a593Smuzhiyun .fid = W1_FAMILY_BQ27000,
107*4882a593Smuzhiyun .fops = &bq27xxx_battery_hdq_fops,
108*4882a593Smuzhiyun };
109*4882a593Smuzhiyun
bq27xxx_battery_hdq_init(void)110*4882a593Smuzhiyun static int __init bq27xxx_battery_hdq_init(void)
111*4882a593Smuzhiyun {
112*4882a593Smuzhiyun if (F_ID)
113*4882a593Smuzhiyun bq27xxx_battery_hdq_family.fid = F_ID;
114*4882a593Smuzhiyun
115*4882a593Smuzhiyun return w1_register_family(&bq27xxx_battery_hdq_family);
116*4882a593Smuzhiyun }
117*4882a593Smuzhiyun module_init(bq27xxx_battery_hdq_init);
118*4882a593Smuzhiyun
bq27xxx_battery_hdq_exit(void)119*4882a593Smuzhiyun static void __exit bq27xxx_battery_hdq_exit(void)
120*4882a593Smuzhiyun {
121*4882a593Smuzhiyun w1_unregister_family(&bq27xxx_battery_hdq_family);
122*4882a593Smuzhiyun }
123*4882a593Smuzhiyun module_exit(bq27xxx_battery_hdq_exit);
124*4882a593Smuzhiyun
125*4882a593Smuzhiyun MODULE_AUTHOR("Texas Instruments Ltd");
126*4882a593Smuzhiyun MODULE_DESCRIPTION("BQ27xxx battery monitor HDQ/1-wire driver");
127*4882a593Smuzhiyun MODULE_LICENSE("GPL");
128*4882a593Smuzhiyun MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_BQ27000));
129