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->bus_mutex);
64
65 ret = w1_ds2780_do_io(dev, buf, addr, count, io);
66
67 mutex_unlock(&sl->master->bus_mutex);
68
69 return ret;
70 }
71 EXPORT_SYMBOL(w1_ds2780_io);
72
w1_ds2780_eeprom_cmd(struct device * dev,int addr,int cmd)73 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
74 {
75 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
76
77 if (!dev)
78 return -EINVAL;
79
80 mutex_lock(&sl->master->bus_mutex);
81
82 if (w1_reset_select_slave(sl) == 0) {
83 w1_write_8(sl->master, cmd);
84 w1_write_8(sl->master, addr);
85 }
86
87 mutex_unlock(&sl->master->bus_mutex);
88 return 0;
89 }
90 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
91
w1_slave_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)92 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
93 struct bin_attribute *bin_attr, char *buf,
94 loff_t off, size_t count)
95 {
96 struct device *dev = container_of(kobj, struct device, kobj);
97 return w1_ds2780_io(dev, buf, off, count, 0);
98 }
99
100 static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
101
102 static struct bin_attribute *w1_ds2780_bin_attrs[] = {
103 &bin_attr_w1_slave,
104 NULL,
105 };
106
107 static const struct attribute_group w1_ds2780_group = {
108 .bin_attrs = w1_ds2780_bin_attrs,
109 };
110
111 static const struct attribute_group *w1_ds2780_groups[] = {
112 &w1_ds2780_group,
113 NULL,
114 };
115
116 static DEFINE_IDA(bat_ida);
117
w1_ds2780_add_slave(struct w1_slave * sl)118 static int w1_ds2780_add_slave(struct w1_slave *sl)
119 {
120 int ret;
121 int id;
122 struct platform_device *pdev;
123
124 id = ida_simple_get(&bat_ida, 0, 0, GFP_KERNEL);
125 if (id < 0) {
126 ret = id;
127 goto noid;
128 }
129
130 pdev = platform_device_alloc("ds2780-battery", id);
131 if (!pdev) {
132 ret = -ENOMEM;
133 goto pdev_alloc_failed;
134 }
135 pdev->dev.parent = &sl->dev;
136
137 ret = platform_device_add(pdev);
138 if (ret)
139 goto pdev_add_failed;
140
141 dev_set_drvdata(&sl->dev, pdev);
142
143 return 0;
144
145 pdev_add_failed:
146 platform_device_put(pdev);
147 pdev_alloc_failed:
148 ida_simple_remove(&bat_ida, id);
149 noid:
150 return ret;
151 }
152
w1_ds2780_remove_slave(struct w1_slave * sl)153 static void w1_ds2780_remove_slave(struct w1_slave *sl)
154 {
155 struct platform_device *pdev = dev_get_drvdata(&sl->dev);
156 int id = pdev->id;
157
158 platform_device_unregister(pdev);
159 ida_simple_remove(&bat_ida, id);
160 }
161
162 static struct w1_family_ops w1_ds2780_fops = {
163 .add_slave = w1_ds2780_add_slave,
164 .remove_slave = w1_ds2780_remove_slave,
165 .groups = w1_ds2780_groups,
166 };
167
168 static struct w1_family w1_ds2780_family = {
169 .fid = W1_FAMILY_DS2780,
170 .fops = &w1_ds2780_fops,
171 };
172
w1_ds2780_init(void)173 static int __init w1_ds2780_init(void)
174 {
175 ida_init(&bat_ida);
176 return w1_register_family(&w1_ds2780_family);
177 }
178
w1_ds2780_exit(void)179 static void __exit w1_ds2780_exit(void)
180 {
181 w1_unregister_family(&w1_ds2780_family);
182 ida_destroy(&bat_ida);
183 }
184
185 module_init(w1_ds2780_init);
186 module_exit(w1_ds2780_exit);
187
188 MODULE_LICENSE("GPL");
189 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
190 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
191 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));
192