1/*
2 *  dac7512.c - Linux kernel module for
3 * 	Texas Instruments DAC7512
4 *
5 *  Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
6 *
7 *  This program is free software; you can redistribute it and/or modify
8 *  it under the terms of the GNU General Public License as published by
9 *  the Free Software Foundation; either version 2 of the License, or
10 *  (at your option) any later version.
11 *
12 *  This program is distributed in the hope that it will be useful,
13 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 *  GNU General Public License for more details.
16 *
17 *  You should have received a copy of the GNU General Public License
18 *  along with this program; if not, write to the Free Software
19 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <linux/module.h>
23#include <linux/spi/spi.h>
24#include <linux/of.h>
25
26static ssize_t dac7512_store_val(struct device *dev,
27				 struct device_attribute *attr,
28				 const char *buf, size_t count)
29{
30	struct spi_device *spi = to_spi_device(dev);
31	unsigned char tmp[2];
32	unsigned long val;
33	int ret;
34
35	ret = kstrtoul(buf, 10, &val);
36	if (ret)
37		return ret;
38
39	tmp[0] = val >> 8;
40	tmp[1] = val & 0xff;
41	spi_write(spi, tmp, sizeof(tmp));
42	return count;
43}
44
45static DEVICE_ATTR(value, S_IWUSR, NULL, dac7512_store_val);
46
47static struct attribute *dac7512_attributes[] = {
48	&dev_attr_value.attr,
49	NULL
50};
51
52static const struct attribute_group dac7512_attr_group = {
53	.attrs = dac7512_attributes,
54};
55
56static int dac7512_probe(struct spi_device *spi)
57{
58	int ret;
59
60	spi->bits_per_word = 8;
61	spi->mode = SPI_MODE_0;
62	ret = spi_setup(spi);
63	if (ret < 0)
64		return ret;
65
66	return sysfs_create_group(&spi->dev.kobj, &dac7512_attr_group);
67}
68
69static int dac7512_remove(struct spi_device *spi)
70{
71	sysfs_remove_group(&spi->dev.kobj, &dac7512_attr_group);
72	return 0;
73}
74
75static const struct spi_device_id dac7512_id_table[] = {
76	{ "dac7512", 0 },
77	{ }
78};
79MODULE_DEVICE_TABLE(spi, dac7512_id_table);
80
81#ifdef CONFIG_OF
82static const struct of_device_id dac7512_of_match[] = {
83	{ .compatible = "ti,dac7512", },
84	{ }
85};
86MODULE_DEVICE_TABLE(of, dac7512_of_match);
87#endif
88
89static struct spi_driver dac7512_driver = {
90	.driver = {
91		.name	= "dac7512",
92		.of_match_table = of_match_ptr(dac7512_of_match),
93	},
94	.probe	= dac7512_probe,
95	.remove	= dac7512_remove,
96	.id_table = dac7512_id_table,
97};
98
99module_spi_driver(dac7512_driver);
100
101MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
102MODULE_DESCRIPTION("DAC7512 16-bit DAC");
103MODULE_LICENSE("GPL v2");
104