1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * 1-Wire implementation for the ds2780 chip
4 *
5 * Copyright (C) 2010 Indesign, LLC
6 *
7 * Author: Clifton Barnes <cabarnes@indesign-llc.com>
8 *
9 * Based on w1-ds2760 driver
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/device.h>
15 #include <linux/types.h>
16 #include <linux/platform_device.h>
17 #include <linux/mutex.h>
18 #include <linux/idr.h>
19
20 #include <linux/w1.h>
21
22 #include "w1_ds2780.h"
23
24 #define W1_FAMILY_DS2780 0x32
25
w1_ds2780_do_io(struct device * dev,char * buf,int addr,size_t count,int io)26 static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,
27 size_t count, int io)
28 {
29 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
30
31 if (addr > DS2780_DATA_SIZE || addr < 0)
32 return 0;
33
34 count = min_t(int, count, DS2780_DATA_SIZE - addr);
35
36 if (w1_reset_select_slave(sl) == 0) {
37 if (io) {
38 w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
39 w1_write_8(sl->master, addr);
40 w1_write_block(sl->master, buf, count);
41 } else {
42 w1_write_8(sl->master, W1_DS2780_READ_DATA);
43 w1_write_8(sl->master, addr);
44 count = w1_read_block(sl->master, buf, count);
45 }
46 }
47
48 return count;
49 }
50
w1_ds2780_io(struct device * dev,char * buf,int addr,size_t count,int io)51 int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
52 int io)
53 {
54 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
55 int ret;
56
57 if (!dev)
58 return -ENODEV;
59
60 mutex_lock(&sl->master->bus_mutex);
61
62 ret = w1_ds2780_do_io(dev, buf, addr, count, io);
63
64 mutex_unlock(&sl->master->bus_mutex);
65
66 return ret;
67 }
68 EXPORT_SYMBOL(w1_ds2780_io);
69
w1_ds2780_eeprom_cmd(struct device * dev,int addr,int cmd)70 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
71 {
72 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
73
74 if (!dev)
75 return -EINVAL;
76
77 mutex_lock(&sl->master->bus_mutex);
78
79 if (w1_reset_select_slave(sl) == 0) {
80 w1_write_8(sl->master, cmd);
81 w1_write_8(sl->master, addr);
82 }
83
84 mutex_unlock(&sl->master->bus_mutex);
85 return 0;
86 }
87 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
88
w1_slave_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)89 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
90 struct bin_attribute *bin_attr, char *buf,
91 loff_t off, size_t count)
92 {
93 struct device *dev = kobj_to_dev(kobj);
94 return w1_ds2780_io(dev, buf, off, count, 0);
95 }
96
97 static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
98
99 static struct bin_attribute *w1_ds2780_bin_attrs[] = {
100 &bin_attr_w1_slave,
101 NULL,
102 };
103
104 static const struct attribute_group w1_ds2780_group = {
105 .bin_attrs = w1_ds2780_bin_attrs,
106 };
107
108 static const struct attribute_group *w1_ds2780_groups[] = {
109 &w1_ds2780_group,
110 NULL,
111 };
112
w1_ds2780_add_slave(struct w1_slave * sl)113 static int w1_ds2780_add_slave(struct w1_slave *sl)
114 {
115 int ret;
116 struct platform_device *pdev;
117
118 pdev = platform_device_alloc("ds2780-battery", PLATFORM_DEVID_AUTO);
119 if (!pdev)
120 return -ENOMEM;
121 pdev->dev.parent = &sl->dev;
122
123 ret = platform_device_add(pdev);
124 if (ret)
125 goto pdev_add_failed;
126
127 dev_set_drvdata(&sl->dev, pdev);
128
129 return 0;
130
131 pdev_add_failed:
132 platform_device_put(pdev);
133
134 return ret;
135 }
136
w1_ds2780_remove_slave(struct w1_slave * sl)137 static void w1_ds2780_remove_slave(struct w1_slave *sl)
138 {
139 struct platform_device *pdev = dev_get_drvdata(&sl->dev);
140
141 platform_device_unregister(pdev);
142 }
143
144 static const struct w1_family_ops w1_ds2780_fops = {
145 .add_slave = w1_ds2780_add_slave,
146 .remove_slave = w1_ds2780_remove_slave,
147 .groups = w1_ds2780_groups,
148 };
149
150 static struct w1_family w1_ds2780_family = {
151 .fid = W1_FAMILY_DS2780,
152 .fops = &w1_ds2780_fops,
153 };
154 module_w1_family(w1_ds2780_family);
155
156 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
157 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
158 MODULE_LICENSE("GPL");
159 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));
160