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Diffstat (limited to 'drivers/w1/slaves/w1_ds2760.c')
-rw-r--r--drivers/w1/slaves/w1_ds2760.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_ds2760.c b/drivers/w1/slaves/w1_ds2760.c
new file mode 100644
index 000000000000..88a37fbccc3f
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2760.c
@@ -0,0 +1,213 @@
1/*
2 * 1-Wire implementation for the ds2760 chip
3 *
4 * Copyright © 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
5 *
6 * Use consistent with the GNU GPL is permitted,
7 * provided that this copyright notice is
8 * preserved in its entirety in all copies and derived works.
9 *
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 "../w1.h"
21#include "../w1_int.h"
22#include "../w1_family.h"
23#include "w1_ds2760.h"
24
25static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
26 int io)
27{
28 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
29
30 if (!dev)
31 return 0;
32
33 mutex_lock(&sl->master->mutex);
34
35 if (addr > DS2760_DATA_SIZE || addr < 0) {
36 count = 0;
37 goto out;
38 }
39 if (addr + count > DS2760_DATA_SIZE)
40 count = DS2760_DATA_SIZE - addr;
41
42 if (!w1_reset_select_slave(sl)) {
43 if (!io) {
44 w1_write_8(sl->master, W1_DS2760_READ_DATA);
45 w1_write_8(sl->master, addr);
46 count = w1_read_block(sl->master, buf, count);
47 } else {
48 w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
49 w1_write_8(sl->master, addr);
50 w1_write_block(sl->master, buf, count);
51 /* XXX w1_write_block returns void, not n_written */
52 }
53 }
54
55out:
56 mutex_unlock(&sl->master->mutex);
57
58 return count;
59}
60
61int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count)
62{
63 return w1_ds2760_io(dev, buf, addr, count, 0);
64}
65
66int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count)
67{
68 return w1_ds2760_io(dev, buf, addr, count, 1);
69}
70
71static ssize_t w1_ds2760_read_bin(struct kobject *kobj, char *buf, loff_t off,
72 size_t count)
73{
74 struct device *dev = container_of(kobj, struct device, kobj);
75 return w1_ds2760_read(dev, buf, off, count);
76}
77
78static struct bin_attribute w1_ds2760_bin_attr = {
79 .attr = {
80 .name = "w1_slave",
81 .mode = S_IRUGO,
82 .owner = THIS_MODULE,
83 },
84 .size = DS2760_DATA_SIZE,
85 .read = w1_ds2760_read_bin,
86};
87
88static DEFINE_IDR(bat_idr);
89static DEFINE_MUTEX(bat_idr_lock);
90
91static int new_bat_id(void)
92{
93 int ret;
94
95 while (1) {
96 int id;
97
98 ret = idr_pre_get(&bat_idr, GFP_KERNEL);
99 if (ret == 0)
100 return -ENOMEM;
101
102 mutex_lock(&bat_idr_lock);
103 ret = idr_get_new(&bat_idr, NULL, &id);
104 mutex_unlock(&bat_idr_lock);
105
106 if (ret == 0) {
107 ret = id & MAX_ID_MASK;
108 break;
109 } else if (ret == -EAGAIN) {
110 continue;
111 } else {
112 break;
113 }
114 }
115
116 return ret;
117}
118
119static void release_bat_id(int id)
120{
121 mutex_lock(&bat_idr_lock);
122 idr_remove(&bat_idr, id);
123 mutex_unlock(&bat_idr_lock);
124
125 return;
126}
127
128static int w1_ds2760_add_slave(struct w1_slave *sl)
129{
130 int ret;
131 int id;
132 struct platform_device *pdev;
133
134 id = new_bat_id();
135 if (id < 0) {
136 ret = id;
137 goto noid;
138 }
139
140 pdev = platform_device_alloc("ds2760-battery", id);
141 if (!pdev) {
142 ret = -ENOMEM;
143 goto pdev_alloc_failed;
144 }
145 pdev->dev.parent = &sl->dev;
146
147 ret = platform_device_add(pdev);
148 if (ret)
149 goto pdev_add_failed;
150
151 ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
152 if (ret)
153 goto bin_attr_failed;
154
155 dev_set_drvdata(&sl->dev, pdev);
156
157 goto success;
158
159bin_attr_failed:
160pdev_add_failed:
161 platform_device_unregister(pdev);
162pdev_alloc_failed:
163 release_bat_id(id);
164noid:
165success:
166 return ret;
167}
168
169static void w1_ds2760_remove_slave(struct w1_slave *sl)
170{
171 struct platform_device *pdev = dev_get_drvdata(&sl->dev);
172 int id = pdev->id;
173
174 platform_device_unregister(pdev);
175 release_bat_id(id);
176 sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
177
178 return;
179}
180
181static struct w1_family_ops w1_ds2760_fops = {
182 .add_slave = w1_ds2760_add_slave,
183 .remove_slave = w1_ds2760_remove_slave,
184};
185
186static struct w1_family w1_ds2760_family = {
187 .fid = W1_FAMILY_DS2760,
188 .fops = &w1_ds2760_fops,
189};
190
191static int __init w1_ds2760_init(void)
192{
193 printk(KERN_INFO "1-Wire driver for the DS2760 battery monitor "
194 " chip - (c) 2004-2005, Szabolcs Gyurko\n");
195 idr_init(&bat_idr);
196 return w1_register_family(&w1_ds2760_family);
197}
198
199static void __exit w1_ds2760_exit(void)
200{
201 w1_unregister_family(&w1_ds2760_family);
202 idr_destroy(&bat_idr);
203}
204
205EXPORT_SYMBOL(w1_ds2760_read);
206EXPORT_SYMBOL(w1_ds2760_write);
207
208module_init(w1_ds2760_init);
209module_exit(w1_ds2760_exit);
210
211MODULE_LICENSE("GPL");
212MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
213MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");