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drivers/misc/ti_dac7512.c 2.47 KB
4d00928c1   Daniel Mack   drivers/misc: add...
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  /*
   *  dac7512.c - Linux kernel module for
   * 	Texas Instruments DAC7512
   *
   *  Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/spi/spi.h>
  
  #define DAC7512_DRV_NAME	"dac7512"
  #define DRIVER_VERSION		"1.0"
  
  static ssize_t dac7512_store_val(struct device *dev,
  				 struct device_attribute *attr,
  				 const char *buf, size_t count)
  {
  	struct spi_device *spi = to_spi_device(dev);
  	unsigned char tmp[2];
  	unsigned long val;
  
  	if (strict_strtoul(buf, 10, &val) < 0)
  		return -EINVAL;
  
  	tmp[0] = val >> 8;
  	tmp[1] = val & 0xff;
  	spi_write(spi, tmp, sizeof(tmp));
  	return count;
  }
  
  static DEVICE_ATTR(value, S_IWUSR, NULL, dac7512_store_val);
  
  static struct attribute *dac7512_attributes[] = {
  	&dev_attr_value.attr,
  	NULL
  };
  
  static const struct attribute_group dac7512_attr_group = {
  	.attrs = dac7512_attributes,
  };
  
  static int __devinit dac7512_probe(struct spi_device *spi)
  {
  	int ret;
  
  	spi->bits_per_word = 8;
  	spi->mode = SPI_MODE_0;
  	ret = spi_setup(spi);
  	if (ret < 0)
  		return ret;
  
  	return sysfs_create_group(&spi->dev.kobj, &dac7512_attr_group);
  }
  
  static int __devexit dac7512_remove(struct spi_device *spi)
  {
  	sysfs_remove_group(&spi->dev.kobj, &dac7512_attr_group);
  	return 0;
  }
  
  static struct spi_driver dac7512_driver = {
  	.driver = {
  		.name	= DAC7512_DRV_NAME,
  		.owner	= THIS_MODULE,
  	},
  	.probe	= dac7512_probe,
  	.remove	= __devexit_p(dac7512_remove),
  };
  
  static int __init dac7512_init(void)
  {
  	return spi_register_driver(&dac7512_driver);
  }
  
  static void __exit dac7512_exit(void)
  {
  	spi_unregister_driver(&dac7512_driver);
  }
  
  MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
  MODULE_DESCRIPTION("DAC7512 16-bit DAC");
  MODULE_LICENSE("GPL v2");
  MODULE_VERSION(DRIVER_VERSION);
  
  module_init(dac7512_init);
  module_exit(dac7512_exit);