1 /*
2 * 1-Wire implementation for the ds2780 chip
3 *
4 * Copyright (C) 2010 Indesign, LLC
5 *
6 * Author: Clifton Barnes <cabarnes@indesign-llc.com>
7 *
8 * Based on w1-ds2760 driver
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 #include <linux/types.h>
20 #include <linux/platform_device.h>
21 #include <linux/mutex.h>
22 #include <linux/idr.h>
23
24 #include "../w1.h"
25 #include "../w1_int.h"
26 #include "../w1_family.h"
27 #include "w1_ds2780.h"
28
w1_ds2780_do_io(struct device * dev,char * buf,int addr,size_t count,int io)29 static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,
30 size_t count, int io)
31 {
32 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
33
34 if (addr > DS2780_DATA_SIZE || addr < 0)
35 return 0;
36
37 count = min_t(int, count, DS2780_DATA_SIZE - addr);
38
39 if (w1_reset_select_slave(sl) == 0) {
40 if (io) {
41 w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
42 w1_write_8(sl->master, addr);
43 w1_write_block(sl->master, buf, count);
44 } else {
45 w1_write_8(sl->master, W1_DS2780_READ_DATA);
46 w1_write_8(sl->master, addr);
47 count = w1_read_block(sl->master, buf, count);
48 }
49 }
50
51 return count;
52 }
53
w1_ds2780_io(struct device * dev,char * buf,int addr,size_t count,int io)54 int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
55 int io)
56 {
57 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
58 int ret;
59
60 if (!dev)
61 return -ENODEV;
62
63 mutex_lock(&sl->master->mutex);
64
65 ret = w1_ds2780_do_io(dev, buf, addr, count, io);
66
67 mutex_unlock(&sl->master->mutex);
68
69 return ret;
70 }
71 EXPORT_SYMBOL(w1_ds2780_io);
72
w1_ds2780_io_nolock(struct device * dev,char * buf,int addr,size_t count,int io)73 int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr, size_t count,
74 int io)
75 {
76 int ret;
77
78 if (!dev)
79 return -ENODEV;
80
81 ret = w1_ds2780_do_io(dev, buf, addr, count, io);
82
83 return ret;
84 }
85 EXPORT_SYMBOL(w1_ds2780_io_nolock);
86
w1_ds2780_eeprom_cmd(struct device * dev,int addr,int cmd)87 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
88 {
89 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
90
91 if (!dev)
92 return -EINVAL;
93
94 mutex_lock(&sl->master->mutex);
95
96 if (w1_reset_select_slave(sl) == 0) {
97 w1_write_8(sl->master, cmd);
98 w1_write_8(sl->master, addr);
99 }
100
101 mutex_unlock(&sl->master->mutex);
102 return 0;
103 }
104 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
105
w1_ds2780_read_bin(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)106 static ssize_t w1_ds2780_read_bin(struct file *filp,
107 struct kobject *kobj,
108 struct bin_attribute *bin_attr,
109 char *buf, loff_t off, size_t count)
110 {
111 struct device *dev = container_of(kobj, struct device, kobj);
112 return w1_ds2780_io(dev, buf, off, count, 0);
113 }
114
115 static struct bin_attribute w1_ds2780_bin_attr = {
116 .attr = {
117 .name = "w1_slave",
118 .mode = S_IRUGO,
119 },
120 .size = DS2780_DATA_SIZE,
121 .read = w1_ds2780_read_bin,
122 };
123
124 static DEFINE_IDA(bat_ida);
125
w1_ds2780_add_slave(struct w1_slave * sl)126 static int w1_ds2780_add_slave(struct w1_slave *sl)
127 {
128 int ret;
129 int id;
130 struct platform_device *pdev;
131
132 id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL);
133 if (id < 0) {
134 ret = id;
135 goto noid;
136 }
137
138 pdev = platform_device_alloc("ds2780-battery", id);
139 if (!pdev) {
140 ret = -ENOMEM;
141 goto pdev_alloc_failed;
142 }
143 pdev->dev.parent = &sl->dev;
144
145 ret = platform_device_add(pdev);
146 if (ret)
147 goto pdev_add_failed;
148
149 ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr);
150 if (ret)
151 goto bin_attr_failed;
152
153 dev_set_drvdata(&sl->dev, pdev);
154
155 return 0;
156
157 bin_attr_failed:
158 pdev_add_failed:
159 platform_device_unregister(pdev);
160 pdev_alloc_failed:
161 ida_simple_remove(&bat_ida, id);
162 noid:
163 return ret;
164 }
165
w1_ds2780_remove_slave(struct w1_slave * sl)166 static void w1_ds2780_remove_slave(struct w1_slave *sl)
167 {
168 struct platform_device *pdev = dev_get_drvdata(&sl->dev);
169 int id = pdev->id;
170
171 platform_device_unregister(pdev);
172 ida_simple_remove(&bat_ida, id);
173 sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr);
174 }
175
176 static struct w1_family_ops w1_ds2780_fops = {
177 .add_slave = w1_ds2780_add_slave,
178 .remove_slave = w1_ds2780_remove_slave,
179 };
180
181 static struct w1_family w1_ds2780_family = {
182 .fid = W1_FAMILY_DS2780,
183 .fops = &w1_ds2780_fops,
184 };
185
w1_ds2780_init(void)186 static int __init w1_ds2780_init(void)
187 {
188 ida_init(&bat_ida);
189 return w1_register_family(&w1_ds2780_family);
190 }
191
w1_ds2780_exit(void)192 static void __exit w1_ds2780_exit(void)
193 {
194 w1_unregister_family(&w1_ds2780_family);
195 ida_destroy(&bat_ida);
196 }
197
198 module_init(w1_ds2780_init);
199 module_exit(w1_ds2780_exit);
200
201 MODULE_LICENSE("GPL");
202 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
203 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
204