| Daniel Mack | 4d00928 | 2009-12-14 18:00:17 -0800 | [diff] [blame] | 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/init.h> |
| 24 | #include <linux/spi/spi.h> |
| 25 | |
| 26 | #define DAC7512_DRV_NAME "dac7512" |
| 27 | #define DRIVER_VERSION "1.0" |
| 28 | |
| 29 | static ssize_t dac7512_store_val(struct device *dev, |
| 30 | struct device_attribute *attr, |
| 31 | const char *buf, size_t count) |
| 32 | { |
| 33 | struct spi_device *spi = to_spi_device(dev); |
| 34 | unsigned char tmp[2]; |
| 35 | unsigned long val; |
| 36 | |
| 37 | if (strict_strtoul(buf, 10, &val) < 0) |
| 38 | return -EINVAL; |
| 39 | |
| 40 | tmp[0] = val >> 8; |
| 41 | tmp[1] = val & 0xff; |
| 42 | spi_write(spi, tmp, sizeof(tmp)); |
| 43 | return count; |
| 44 | } |
| 45 | |
| 46 | static DEVICE_ATTR(value, S_IWUSR, NULL, dac7512_store_val); |
| 47 | |
| 48 | static struct attribute *dac7512_attributes[] = { |
| 49 | &dev_attr_value.attr, |
| 50 | NULL |
| 51 | }; |
| 52 | |
| 53 | static const struct attribute_group dac7512_attr_group = { |
| 54 | .attrs = dac7512_attributes, |
| 55 | }; |
| 56 | |
| 57 | static int __devinit dac7512_probe(struct spi_device *spi) |
| 58 | { |
| 59 | int ret; |
| 60 | |
| 61 | spi->bits_per_word = 8; |
| 62 | spi->mode = SPI_MODE_0; |
| 63 | ret = spi_setup(spi); |
| 64 | if (ret < 0) |
| 65 | return ret; |
| 66 | |
| 67 | return sysfs_create_group(&spi->dev.kobj, &dac7512_attr_group); |
| 68 | } |
| 69 | |
| 70 | static int __devexit dac7512_remove(struct spi_device *spi) |
| 71 | { |
| 72 | sysfs_remove_group(&spi->dev.kobj, &dac7512_attr_group); |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | static struct spi_driver dac7512_driver = { |
| 77 | .driver = { |
| 78 | .name = DAC7512_DRV_NAME, |
| 79 | .owner = THIS_MODULE, |
| 80 | }, |
| 81 | .probe = dac7512_probe, |
| 82 | .remove = __devexit_p(dac7512_remove), |
| 83 | }; |
| 84 | |
| 85 | static int __init dac7512_init(void) |
| 86 | { |
| 87 | return spi_register_driver(&dac7512_driver); |
| 88 | } |
| 89 | |
| 90 | static void __exit dac7512_exit(void) |
| 91 | { |
| 92 | spi_unregister_driver(&dac7512_driver); |
| 93 | } |
| 94 | |
| 95 | MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); |
| 96 | MODULE_DESCRIPTION("DAC7512 16-bit DAC"); |
| 97 | MODULE_LICENSE("GPL v2"); |
| 98 | MODULE_VERSION(DRIVER_VERSION); |
| 99 | |
| 100 | module_init(dac7512_init); |
| 101 | module_exit(dac7512_exit); |