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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 | ||
29 | int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count, | |
30 | int io) | |
31 | { | |
32 | struct w1_slave *sl = container_of(dev, struct w1_slave, dev); | |
33 | ||
34 | if (!dev) | |
35 | return -ENODEV; | |
36 | ||
37 | mutex_lock(&sl->master->mutex); | |
38 | ||
39 | if (addr > DS2780_DATA_SIZE || addr < 0) { | |
40 | count = 0; | |
41 | goto out; | |
42 | } | |
43 | count = min_t(int, count, DS2780_DATA_SIZE - addr); | |
44 | ||
45 | if (w1_reset_select_slave(sl) == 0) { | |
46 | if (io) { | |
47 | w1_write_8(sl->master, W1_DS2780_WRITE_DATA); | |
48 | w1_write_8(sl->master, addr); | |
49 | w1_write_block(sl->master, buf, count); | |
50 | /* XXX w1_write_block returns void, not n_written */ | |
51 | } else { | |
52 | w1_write_8(sl->master, W1_DS2780_READ_DATA); | |
53 | w1_write_8(sl->master, addr); | |
54 | count = w1_read_block(sl->master, buf, count); | |
55 | } | |
56 | } | |
57 | ||
58 | out: | |
59 | mutex_unlock(&sl->master->mutex); | |
60 | ||
61 | return count; | |
62 | } | |
63 | EXPORT_SYMBOL(w1_ds2780_io); | |
64 | ||
65 | int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd) | |
66 | { | |
67 | struct w1_slave *sl = container_of(dev, struct w1_slave, dev); | |
68 | ||
69 | if (!dev) | |
70 | return -EINVAL; | |
71 | ||
72 | mutex_lock(&sl->master->mutex); | |
73 | ||
74 | if (w1_reset_select_slave(sl) == 0) { | |
75 | w1_write_8(sl->master, cmd); | |
76 | w1_write_8(sl->master, addr); | |
77 | } | |
78 | ||
79 | mutex_unlock(&sl->master->mutex); | |
80 | return 0; | |
81 | } | |
82 | EXPORT_SYMBOL(w1_ds2780_eeprom_cmd); | |
83 | ||
84 | static ssize_t w1_ds2780_read_bin(struct file *filp, | |
85 | struct kobject *kobj, | |
86 | struct bin_attribute *bin_attr, | |
87 | char *buf, loff_t off, size_t count) | |
88 | { | |
89 | struct device *dev = container_of(kobj, struct device, kobj); | |
90 | return w1_ds2780_io(dev, buf, off, count, 0); | |
91 | } | |
92 | ||
93 | static struct bin_attribute w1_ds2780_bin_attr = { | |
94 | .attr = { | |
95 | .name = "w1_slave", | |
96 | .mode = S_IRUGO, | |
97 | }, | |
98 | .size = DS2780_DATA_SIZE, | |
99 | .read = w1_ds2780_read_bin, | |
100 | }; | |
101 | ||
102 | static DEFINE_IDR(bat_idr); | |
103 | static DEFINE_MUTEX(bat_idr_lock); | |
104 | ||
105 | static int new_bat_id(void) | |
106 | { | |
107 | int ret; | |
108 | ||
109 | while (1) { | |
110 | int id; | |
111 | ||
112 | ret = idr_pre_get(&bat_idr, GFP_KERNEL); | |
113 | if (ret == 0) | |
114 | return -ENOMEM; | |
115 | ||
116 | mutex_lock(&bat_idr_lock); | |
117 | ret = idr_get_new(&bat_idr, NULL, &id); | |
118 | mutex_unlock(&bat_idr_lock); | |
119 | ||
120 | if (ret == 0) { | |
121 | ret = id & MAX_ID_MASK; | |
122 | break; | |
123 | } else if (ret == -EAGAIN) { | |
124 | continue; | |
125 | } else { | |
126 | break; | |
127 | } | |
128 | } | |
129 | ||
130 | return ret; | |
131 | } | |
132 | ||
133 | static void release_bat_id(int id) | |
134 | { | |
135 | mutex_lock(&bat_idr_lock); | |
136 | idr_remove(&bat_idr, id); | |
137 | mutex_unlock(&bat_idr_lock); | |
138 | } | |
139 | ||
140 | static int w1_ds2780_add_slave(struct w1_slave *sl) | |
141 | { | |
142 | int ret; | |
143 | int id; | |
144 | struct platform_device *pdev; | |
145 | ||
146 | id = new_bat_id(); | |
147 | if (id < 0) { | |
148 | ret = id; | |
149 | goto noid; | |
150 | } | |
151 | ||
152 | pdev = platform_device_alloc("ds2780-battery", id); | |
153 | if (!pdev) { | |
154 | ret = -ENOMEM; | |
155 | goto pdev_alloc_failed; | |
156 | } | |
157 | pdev->dev.parent = &sl->dev; | |
158 | ||
159 | ret = platform_device_add(pdev); | |
160 | if (ret) | |
161 | goto pdev_add_failed; | |
162 | ||
163 | ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr); | |
164 | if (ret) | |
165 | goto bin_attr_failed; | |
166 | ||
167 | dev_set_drvdata(&sl->dev, pdev); | |
168 | ||
169 | return 0; | |
170 | ||
171 | bin_attr_failed: | |
172 | pdev_add_failed: | |
173 | platform_device_unregister(pdev); | |
174 | pdev_alloc_failed: | |
175 | release_bat_id(id); | |
176 | noid: | |
177 | return ret; | |
178 | } | |
179 | ||
180 | static void w1_ds2780_remove_slave(struct w1_slave *sl) | |
181 | { | |
182 | struct platform_device *pdev = dev_get_drvdata(&sl->dev); | |
183 | int id = pdev->id; | |
184 | ||
185 | platform_device_unregister(pdev); | |
186 | release_bat_id(id); | |
187 | sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr); | |
188 | } | |
189 | ||
190 | static struct w1_family_ops w1_ds2780_fops = { | |
191 | .add_slave = w1_ds2780_add_slave, | |
192 | .remove_slave = w1_ds2780_remove_slave, | |
193 | }; | |
194 | ||
195 | static struct w1_family w1_ds2780_family = { | |
196 | .fid = W1_FAMILY_DS2780, | |
197 | .fops = &w1_ds2780_fops, | |
198 | }; | |
199 | ||
200 | static int __init w1_ds2780_init(void) | |
201 | { | |
202 | idr_init(&bat_idr); | |
203 | return w1_register_family(&w1_ds2780_family); | |
204 | } | |
205 | ||
206 | static void __exit w1_ds2780_exit(void) | |
207 | { | |
208 | w1_unregister_family(&w1_ds2780_family); | |
209 | idr_destroy(&bat_idr); | |
210 | } | |
211 | ||
212 | module_init(w1_ds2780_init); | |
213 | module_exit(w1_ds2780_exit); | |
214 | ||
215 | MODULE_LICENSE("GPL"); | |
216 | MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>"); | |
217 | MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC"); |