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->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}
71EXPORT_SYMBOL(w1_ds2780_io);
72
73int 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}
85EXPORT_SYMBOL(w1_ds2780_io_nolock);
86
87int 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}
104EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
105
106static 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
115static 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
124static DEFINE_IDA(bat_ida);
125
126static 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
157bin_attr_failed:
158pdev_add_failed:
159	platform_device_unregister(pdev);
160pdev_alloc_failed:
161	ida_simple_remove(&bat_ida, id);
162noid:
163	return ret;
164}
165
166static 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
176static struct w1_family_ops w1_ds2780_fops = {
177	.add_slave    = w1_ds2780_add_slave,
178	.remove_slave = w1_ds2780_remove_slave,
179};
180
181static struct w1_family w1_ds2780_family = {
182	.fid = W1_FAMILY_DS2780,
183	.fops = &w1_ds2780_fops,
184};
185
186static int __init w1_ds2780_init(void)
187{
188	ida_init(&bat_ida);
189	return w1_register_family(&w1_ds2780_family);
190}
191
192static void __exit w1_ds2780_exit(void)
193{
194	w1_unregister_family(&w1_ds2780_family);
195	ida_destroy(&bat_ida);
196}
197
198module_init(w1_ds2780_init);
199module_exit(w1_ds2780_exit);
200
201MODULE_LICENSE("GPL");
202MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
203MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
204