LXR linux/drivers/misc/ti

   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                .owner  = THIS_MODULE,
  93                .of_match_table = of_match_ptr(dac7512_of_match),
  94        },
  95        .probe  = dac7512_probe,
  96        .remove = dac7512_remove,
  97        .id_table = dac7512_id_table,
  98};
  99
 100module_spi_driver(dac7512_driver);
 101
 102MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
 103MODULE_DESCRIPTION("DAC7512 16-bit DAC");
 104MODULE_LICENSE("GPL v2");
 105