104 lines
2.5 KiB
C
104 lines
2.5 KiB
C
/*
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* dac7512.c - Linux kernel module for
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* Texas Instruments DAC7512
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*
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* Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/spi/spi.h>
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#include <linux/of.h>
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static ssize_t dac7512_store_val(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct spi_device *spi = to_spi_device(dev);
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unsigned char tmp[2];
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unsigned long val;
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int ret;
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ret = kstrtoul(buf, 10, &val);
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if (ret)
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return ret;
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tmp[0] = val >> 8;
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tmp[1] = val & 0xff;
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spi_write(spi, tmp, sizeof(tmp));
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return count;
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}
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static DEVICE_ATTR(value, S_IWUSR, NULL, dac7512_store_val);
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static struct attribute *dac7512_attributes[] = {
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&dev_attr_value.attr,
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NULL
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};
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static const struct attribute_group dac7512_attr_group = {
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.attrs = dac7512_attributes,
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};
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static int dac7512_probe(struct spi_device *spi)
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{
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int ret;
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spi->bits_per_word = 8;
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spi->mode = SPI_MODE_0;
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ret = spi_setup(spi);
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if (ret < 0)
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return ret;
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return sysfs_create_group(&spi->dev.kobj, &dac7512_attr_group);
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}
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static int dac7512_remove(struct spi_device *spi)
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{
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sysfs_remove_group(&spi->dev.kobj, &dac7512_attr_group);
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return 0;
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}
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static const struct spi_device_id dac7512_id_table[] = {
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{ "dac7512", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(spi, dac7512_id_table);
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#ifdef CONFIG_OF
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static const struct of_device_id dac7512_of_match[] = {
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{ .compatible = "ti,dac7512", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, dac7512_of_match);
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#endif
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static struct spi_driver dac7512_driver = {
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.driver = {
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.name = "dac7512",
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.of_match_table = of_match_ptr(dac7512_of_match),
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},
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.probe = dac7512_probe,
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.remove = dac7512_remove,
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.id_table = dac7512_id_table,
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};
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module_spi_driver(dac7512_driver);
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MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
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MODULE_DESCRIPTION("DAC7512 16-bit DAC");
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MODULE_LICENSE("GPL v2");
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