1/* 2 * Driver for ADI Direct Digital Synthesis ad9850 3 * 4 * Copyright (c) 2010-2010 Analog Devices Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 */ 11#include <linux/types.h> 12#include <linux/mutex.h> 13#include <linux/device.h> 14#include <linux/spi/spi.h> 15#include <linux/slab.h> 16#include <linux/sysfs.h> 17#include <linux/module.h> 18 19#include "../iio.h" 20#include "../sysfs.h" 21 22#define DRV_NAME "ad9850" 23 24#define value_mask (u16)0xf000 25#define addr_shift 12 26 27/* Register format: 4 bits addr + 12 bits value */ 28struct ad9850_config { 29 u8 control[5]; 30}; 31 32struct ad9850_state { 33 struct mutex lock; 34 struct spi_device *sdev; 35}; 36 37static ssize_t ad9850_set_parameter(struct device *dev, 38 struct device_attribute *attr, 39 const char *buf, 40 size_t len) 41{ 42 struct spi_message msg; 43 struct spi_transfer xfer; 44 int ret; 45 struct ad9850_config *config = (struct ad9850_config *)buf; 46 struct iio_dev *idev = dev_get_drvdata(dev); 47 struct ad9850_state *st = iio_priv(idev); 48 49 xfer.len = len; 50 xfer.tx_buf = config; 51 mutex_lock(&st->lock); 52 53 spi_message_init(&msg); 54 spi_message_add_tail(&xfer, &msg); 55 ret = spi_sync(st->sdev, &msg); 56 if (ret) 57 goto error_ret; 58error_ret: 59 mutex_unlock(&st->lock); 60 61 return ret ? ret : len; 62} 63 64static IIO_DEVICE_ATTR(dds, S_IWUSR, NULL, ad9850_set_parameter, 0); 65 66static struct attribute *ad9850_attributes[] = { 67 &iio_dev_attr_dds.dev_attr.attr, 68 NULL, 69}; 70 71static const struct attribute_group ad9850_attribute_group = { 72 .attrs = ad9850_attributes, 73}; 74 75static const struct iio_info ad9850_info = { 76 .attrs = &ad9850_attribute_group, 77 .driver_module = THIS_MODULE, 78}; 79 80static int __devinit ad9850_probe(struct spi_device *spi) 81{ 82 struct ad9850_state *st; 83 struct iio_dev *idev; 84 int ret = 0; 85 86 idev = iio_allocate_device(sizeof(*st)); 87 if (idev == NULL) { 88 ret = -ENOMEM; 89 goto error_ret; 90 } 91 spi_set_drvdata(spi, idev); 92 st = iio_priv(idev); 93 mutex_init(&st->lock); 94 st->sdev = spi; 95 96 idev->dev.parent = &spi->dev; 97 idev->info = &ad9850_info; 98 idev->modes = INDIO_DIRECT_MODE; 99 100 ret = iio_device_register(idev); 101 if (ret) 102 goto error_free_dev; 103 spi->max_speed_hz = 2000000; 104 spi->mode = SPI_MODE_3; 105 spi->bits_per_word = 16; 106 spi_setup(spi); 107 108 return 0; 109 110error_free_dev: 111 iio_free_device(idev); 112error_ret: 113 return ret; 114} 115 116static int __devexit ad9850_remove(struct spi_device *spi) 117{ 118 iio_device_unregister(spi_get_drvdata(spi)); 119 iio_free_device(spi_get_drvdata(spi)); 120 121 return 0; 122} 123 124static struct spi_driver ad9850_driver = { 125 .driver = { 126 .name = DRV_NAME, 127 .owner = THIS_MODULE, 128 }, 129 .probe = ad9850_probe, 130 .remove = __devexit_p(ad9850_remove), 131}; 132module_spi_driver(ad9850_driver); 133 134MODULE_AUTHOR("Cliff Cai"); 135MODULE_DESCRIPTION("Analog Devices ad9850 driver"); 136MODULE_LICENSE("GPL v2"); 137MODULE_ALIAS("spi:" DRV_NAME); 138