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");