blob: 877daf74159c98b7c8a77284d6ce31105b6fb9d3 [file] [log] [blame]
Renata Sayakhovafef37e92012-02-29 14:58:53 +01001/*
2 * 1-Wire implementation for the ds2781 chip
3 *
4 * Author: Renata Sayakhova <renata@oktetlabs.ru>
5 *
6 * Based on w1-ds2780 driver
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/device.h>
17#include <linux/types.h>
18#include <linux/platform_device.h>
19#include <linux/mutex.h>
20#include <linux/idr.h>
21
22#include "../w1.h"
23#include "../w1_int.h"
24#include "../w1_family.h"
25#include "w1_ds2781.h"
26
27static int w1_ds2781_do_io(struct device *dev, char *buf, int addr,
28 size_t count, int io)
29{
30 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
31
32 if (addr > DS2781_DATA_SIZE || addr < 0)
33 return 0;
34
35 count = min_t(int, count, DS2781_DATA_SIZE - addr);
36
37 if (w1_reset_select_slave(sl) == 0) {
38 if (io) {
39 w1_write_8(sl->master, W1_DS2781_WRITE_DATA);
40 w1_write_8(sl->master, addr);
41 w1_write_block(sl->master, buf, count);
42 } else {
43 w1_write_8(sl->master, W1_DS2781_READ_DATA);
44 w1_write_8(sl->master, addr);
45 count = w1_read_block(sl->master, buf, count);
46 }
47 }
48
49 return count;
50}
51
52int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
53 int io)
54{
55 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
56 int ret;
57
58 if (!dev)
59 return -ENODEV;
60
NeilBrownb02f8be2012-05-18 15:59:52 +100061 mutex_lock(&sl->master->bus_mutex);
Renata Sayakhovafef37e92012-02-29 14:58:53 +010062
63 ret = w1_ds2781_do_io(dev, buf, addr, count, io);
64
NeilBrownb02f8be2012-05-18 15:59:52 +100065 mutex_unlock(&sl->master->bus_mutex);
Renata Sayakhovafef37e92012-02-29 14:58:53 +010066
67 return ret;
68}
69EXPORT_SYMBOL(w1_ds2781_io);
70
Renata Sayakhovafef37e92012-02-29 14:58:53 +010071int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
72{
73 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
74
75 if (!dev)
76 return -EINVAL;
77
NeilBrownb02f8be2012-05-18 15:59:52 +100078 mutex_lock(&sl->master->bus_mutex);
Renata Sayakhovafef37e92012-02-29 14:58:53 +010079
80 if (w1_reset_select_slave(sl) == 0) {
81 w1_write_8(sl->master, cmd);
82 w1_write_8(sl->master, addr);
83 }
84
NeilBrownb02f8be2012-05-18 15:59:52 +100085 mutex_unlock(&sl->master->bus_mutex);
Renata Sayakhovafef37e92012-02-29 14:58:53 +010086 return 0;
87}
88EXPORT_SYMBOL(w1_ds2781_eeprom_cmd);
89
90static ssize_t w1_ds2781_read_bin(struct file *filp,
91 struct kobject *kobj,
92 struct bin_attribute *bin_attr,
93 char *buf, loff_t off, size_t count)
94{
95 struct device *dev = container_of(kobj, struct device, kobj);
96 return w1_ds2781_io(dev, buf, off, count, 0);
97}
98
99static struct bin_attribute w1_ds2781_bin_attr = {
100 .attr = {
101 .name = "w1_slave",
102 .mode = S_IRUGO,
103 },
104 .size = DS2781_DATA_SIZE,
105 .read = w1_ds2781_read_bin,
106};
107
108static DEFINE_IDA(bat_ida);
109
110static int w1_ds2781_add_slave(struct w1_slave *sl)
111{
112 int ret;
113 int id;
114 struct platform_device *pdev;
115
116 id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL);
117 if (id < 0) {
118 ret = id;
119 goto noid;
120 }
121
122 pdev = platform_device_alloc("ds2781-battery", id);
123 if (!pdev) {
124 ret = -ENOMEM;
125 goto pdev_alloc_failed;
126 }
127 pdev->dev.parent = &sl->dev;
128
129 ret = platform_device_add(pdev);
130 if (ret)
131 goto pdev_add_failed;
132
133 ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2781_bin_attr);
134 if (ret)
135 goto bin_attr_failed;
136
137 dev_set_drvdata(&sl->dev, pdev);
138
139 return 0;
140
141bin_attr_failed:
142pdev_add_failed:
143 platform_device_unregister(pdev);
144pdev_alloc_failed:
145 ida_simple_remove(&bat_ida, id);
146noid:
147 return ret;
148}
149
150static void w1_ds2781_remove_slave(struct w1_slave *sl)
151{
152 struct platform_device *pdev = dev_get_drvdata(&sl->dev);
153 int id = pdev->id;
154
155 platform_device_unregister(pdev);
156 ida_simple_remove(&bat_ida, id);
157 sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2781_bin_attr);
158}
159
160static struct w1_family_ops w1_ds2781_fops = {
161 .add_slave = w1_ds2781_add_slave,
162 .remove_slave = w1_ds2781_remove_slave,
163};
164
165static struct w1_family w1_ds2781_family = {
166 .fid = W1_FAMILY_DS2781,
167 .fops = &w1_ds2781_fops,
168};
169
170static int __init w1_ds2781_init(void)
171{
172 ida_init(&bat_ida);
173 return w1_register_family(&w1_ds2781_family);
174}
175
176static void __exit w1_ds2781_exit(void)
177{
178 w1_unregister_family(&w1_ds2781_family);
179 ida_destroy(&bat_ida);
180}
181
182module_init(w1_ds2781_init);
183module_exit(w1_ds2781_exit);
184
185MODULE_LICENSE("GPL");
186MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
187MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC");