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 #include <linux/gfp.h>
20
21 #include "../w1.h"
22 #include "../w1_int.h"
23 #include "../w1_family.h"
24 #include "w1_ds2760.h"
25
w1_ds2760_io(struct device * dev,char * buf,int addr,size_t count,int io)26 static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
27 int io)
28 {
29 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
30
31 if (!dev)
32 return 0;
33
34 mutex_lock(&sl->master->bus_mutex);
35
36 if (addr > DS2760_DATA_SIZE || addr < 0) {
37 count = 0;
38 goto out;
39 }
40 if (addr + count > DS2760_DATA_SIZE)
41 count = DS2760_DATA_SIZE - addr;
42
43 if (!w1_reset_select_slave(sl)) {
44 if (!io) {
45 w1_write_8(sl->master, W1_DS2760_READ_DATA);
46 w1_write_8(sl->master, addr);
47 count = w1_read_block(sl->master, buf, count);
48 } else {
49 w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
50 w1_write_8(sl->master, addr);
51 w1_write_block(sl->master, buf, count);
52 /* XXX w1_write_block returns void, not n_written */
53 }
54 }
55
56 out:
57 mutex_unlock(&sl->master->bus_mutex);
58
59 return count;
60 }
61
w1_ds2760_read(struct device * dev,char * buf,int addr,size_t count)62 int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count)
63 {
64 return w1_ds2760_io(dev, buf, addr, count, 0);
65 }
66
w1_ds2760_write(struct device * dev,char * buf,int addr,size_t count)67 int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count)
68 {
69 return w1_ds2760_io(dev, buf, addr, count, 1);
70 }
71
w1_ds2760_eeprom_cmd(struct device * dev,int addr,int cmd)72 static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
73 {
74 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
75
76 if (!dev)
77 return -EINVAL;
78
79 mutex_lock(&sl->master->bus_mutex);
80
81 if (w1_reset_select_slave(sl) == 0) {
82 w1_write_8(sl->master, cmd);
83 w1_write_8(sl->master, addr);
84 }
85
86 mutex_unlock(&sl->master->bus_mutex);
87 return 0;
88 }
89
w1_ds2760_store_eeprom(struct device * dev,int addr)90 int w1_ds2760_store_eeprom(struct device *dev, int addr)
91 {
92 return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
93 }
94
w1_ds2760_recall_eeprom(struct device * dev,int addr)95 int w1_ds2760_recall_eeprom(struct device *dev, int addr)
96 {
97 return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
98 }
99
w1_ds2760_read_bin(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)100 static ssize_t w1_ds2760_read_bin(struct file *filp, struct kobject *kobj,
101 struct bin_attribute *bin_attr,
102 char *buf, loff_t off, size_t count)
103 {
104 struct device *dev = container_of(kobj, struct device, kobj);
105 return w1_ds2760_read(dev, buf, off, count);
106 }
107
108 static struct bin_attribute w1_ds2760_bin_attr = {
109 .attr = {
110 .name = "w1_slave",
111 .mode = S_IRUGO,
112 },
113 .size = DS2760_DATA_SIZE,
114 .read = w1_ds2760_read_bin,
115 };
116
117 static DEFINE_IDA(bat_ida);
118
w1_ds2760_add_slave(struct w1_slave * sl)119 static int w1_ds2760_add_slave(struct w1_slave *sl)
120 {
121 int ret;
122 int id;
123 struct platform_device *pdev;
124
125 id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL);
126 if (id < 0) {
127 ret = id;
128 goto noid;
129 }
130
131 pdev = platform_device_alloc("ds2760-battery", id);
132 if (!pdev) {
133 ret = -ENOMEM;
134 goto pdev_alloc_failed;
135 }
136 pdev->dev.parent = &sl->dev;
137
138 ret = platform_device_add(pdev);
139 if (ret)
140 goto pdev_add_failed;
141
142 ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
143 if (ret)
144 goto bin_attr_failed;
145
146 dev_set_drvdata(&sl->dev, pdev);
147
148 goto success;
149
150 bin_attr_failed:
151 platform_device_del(pdev);
152 pdev_add_failed:
153 platform_device_put(pdev);
154 pdev_alloc_failed:
155 ida_simple_remove(&bat_ida, id);
156 noid:
157 success:
158 return ret;
159 }
160
w1_ds2760_remove_slave(struct w1_slave * sl)161 static void w1_ds2760_remove_slave(struct w1_slave *sl)
162 {
163 struct platform_device *pdev = dev_get_drvdata(&sl->dev);
164 int id = pdev->id;
165
166 platform_device_unregister(pdev);
167 ida_simple_remove(&bat_ida, id);
168 sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
169 }
170
171 static struct w1_family_ops w1_ds2760_fops = {
172 .add_slave = w1_ds2760_add_slave,
173 .remove_slave = w1_ds2760_remove_slave,
174 };
175
176 static struct w1_family w1_ds2760_family = {
177 .fid = W1_FAMILY_DS2760,
178 .fops = &w1_ds2760_fops,
179 };
180
w1_ds2760_init(void)181 static int __init w1_ds2760_init(void)
182 {
183 printk(KERN_INFO "1-Wire driver for the DS2760 battery monitor "
184 " chip - (c) 2004-2005, Szabolcs Gyurko\n");
185 ida_init(&bat_ida);
186 return w1_register_family(&w1_ds2760_family);
187 }
188
w1_ds2760_exit(void)189 static void __exit w1_ds2760_exit(void)
190 {
191 w1_unregister_family(&w1_ds2760_family);
192 ida_destroy(&bat_ida);
193 }
194
195 EXPORT_SYMBOL(w1_ds2760_read);
196 EXPORT_SYMBOL(w1_ds2760_write);
197 EXPORT_SYMBOL(w1_ds2760_store_eeprom);
198 EXPORT_SYMBOL(w1_ds2760_recall_eeprom);
199
200 module_init(w1_ds2760_init);
201 module_exit(w1_ds2760_exit);
202
203 MODULE_LICENSE("GPL");
204 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
205 MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
206