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
29static 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
54int 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}
71EXPORT_SYMBOL(w1_ds2780_io);
72
73int 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}
90EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
91
92static 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
100static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
101
102static struct bin_attribute *w1_ds2780_bin_attrs[] = {
103	&bin_attr_w1_slave,
104	NULL,
105};
106
107static const struct attribute_group w1_ds2780_group = {
108	.bin_attrs = w1_ds2780_bin_attrs,
109};
110
111static const struct attribute_group *w1_ds2780_groups[] = {
112	&w1_ds2780_group,
113	NULL,
114};
115
116static DEFINE_IDA(bat_ida);
117
118static 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
145pdev_add_failed:
146	platform_device_put(pdev);
147pdev_alloc_failed:
148	ida_simple_remove(&bat_ida, id);
149noid:
150	return ret;
151}
152
153static 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
162static 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
168static struct w1_family w1_ds2780_family = {
169	.fid = W1_FAMILY_DS2780,
170	.fops = &w1_ds2780_fops,
171};
172
173static int __init w1_ds2780_init(void)
174{
175	ida_init(&bat_ida);
176	return w1_register_family(&w1_ds2780_family);
177}
178
179static void __exit w1_ds2780_exit(void)
180{
181	w1_unregister_family(&w1_ds2780_family);
182	ida_destroy(&bat_ida);
183}
184
185module_init(w1_ds2780_init);
186module_exit(w1_ds2780_exit);
187
188MODULE_LICENSE("GPL");
189MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
190MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
191MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));
192