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
26static 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
56out:
57	mutex_unlock(&sl->master->bus_mutex);
58
59	return count;
60}
61
62int 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
67int 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
72static 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
90int w1_ds2760_store_eeprom(struct device *dev, int addr)
91{
92	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
93}
94
95int w1_ds2760_recall_eeprom(struct device *dev, int addr)
96{
97	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
98}
99
100static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
101			     struct bin_attribute *bin_attr, char *buf,
102			     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
108static BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE);
109
110static struct bin_attribute *w1_ds2760_bin_attrs[] = {
111	&bin_attr_w1_slave,
112	NULL,
113};
114
115static const struct attribute_group w1_ds2760_group = {
116	.bin_attrs = w1_ds2760_bin_attrs,
117};
118
119static const struct attribute_group *w1_ds2760_groups[] = {
120	&w1_ds2760_group,
121	NULL,
122};
123
124static DEFINE_IDA(bat_ida);
125
126static int w1_ds2760_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("ds2760-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	dev_set_drvdata(&sl->dev, pdev);
150
151	goto success;
152
153pdev_add_failed:
154	platform_device_put(pdev);
155pdev_alloc_failed:
156	ida_simple_remove(&bat_ida, id);
157noid:
158success:
159	return ret;
160}
161
162static void w1_ds2760_remove_slave(struct w1_slave *sl)
163{
164	struct platform_device *pdev = dev_get_drvdata(&sl->dev);
165	int id = pdev->id;
166
167	platform_device_unregister(pdev);
168	ida_simple_remove(&bat_ida, id);
169}
170
171static struct w1_family_ops w1_ds2760_fops = {
172	.add_slave    = w1_ds2760_add_slave,
173	.remove_slave = w1_ds2760_remove_slave,
174	.groups       = w1_ds2760_groups,
175};
176
177static struct w1_family w1_ds2760_family = {
178	.fid = W1_FAMILY_DS2760,
179	.fops = &w1_ds2760_fops,
180};
181
182static int __init w1_ds2760_init(void)
183{
184	pr_info("1-Wire driver for the DS2760 battery monitor chip - (c) 2004-2005, Szabolcs Gyurko\n");
185	ida_init(&bat_ida);
186	return w1_register_family(&w1_ds2760_family);
187}
188
189static void __exit w1_ds2760_exit(void)
190{
191	w1_unregister_family(&w1_ds2760_family);
192	ida_destroy(&bat_ida);
193}
194
195EXPORT_SYMBOL(w1_ds2760_read);
196EXPORT_SYMBOL(w1_ds2760_write);
197EXPORT_SYMBOL(w1_ds2760_store_eeprom);
198EXPORT_SYMBOL(w1_ds2760_recall_eeprom);
199
200module_init(w1_ds2760_init);
201module_exit(w1_ds2760_exit);
202
203MODULE_LICENSE("GPL");
204MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
205MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
206MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));
207