2 * AD7887 SPI ADC driver
4 * Copyright 2010 Analog Devices Inc.
6 * Licensed under the GPL-2 or later.
9 #include <linux/interrupt.h>
10 #include <linux/workqueue.h>
11 #include <linux/device.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/sysfs.h>
15 #include <linux/list.h>
16 #include <linux/spi/spi.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/err.h>
22 #include "../ring_generic.h"
27 static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
29 int ret = spi_sync(st->spi, &st->msg[ch]);
33 return (st->data[(ch * 2)] << 8) | st->data[(ch * 2) + 1];
36 static ssize_t ad7887_scan(struct device *dev,
37 struct device_attribute *attr,
40 struct iio_dev *dev_info = dev_get_drvdata(dev);
41 struct ad7887_state *st = dev_info->dev_data;
42 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
45 mutex_lock(&dev_info->mlock);
46 if (iio_ring_enabled(dev_info))
47 ret = ad7887_scan_from_ring(st, 1 << this_attr->address);
49 ret = ad7887_scan_direct(st, this_attr->address);
50 mutex_unlock(&dev_info->mlock);
55 return sprintf(buf, "%d\n", (ret >> st->chip_info->left_shift) &
56 RES_MASK(st->chip_info->bits));
58 static IIO_DEV_ATTR_IN_RAW(0, ad7887_scan, 0);
59 static IIO_DEV_ATTR_IN_RAW(1, ad7887_scan, 1);
61 static ssize_t ad7887_show_scale(struct device *dev,
62 struct device_attribute *attr,
65 /* Driver currently only support internal vref */
66 struct iio_dev *dev_info = dev_get_drvdata(dev);
67 struct ad7887_state *st = iio_dev_get_devdata(dev_info);
68 /* Corresponds to Vref / 2^(bits) */
69 unsigned int scale_uv = (st->int_vref_mv * 1000) >> st->chip_info->bits;
71 return sprintf(buf, "%d.%d\n", scale_uv / 1000, scale_uv % 1000);
73 static IIO_DEVICE_ATTR(in_scale, S_IRUGO, ad7887_show_scale, NULL, 0);
75 static ssize_t ad7887_show_name(struct device *dev,
76 struct device_attribute *attr,
79 struct iio_dev *dev_info = dev_get_drvdata(dev);
80 struct ad7887_state *st = iio_dev_get_devdata(dev_info);
82 return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
84 static IIO_DEVICE_ATTR(name, S_IRUGO, ad7887_show_name, NULL, 0);
86 static struct attribute *ad7887_attributes[] = {
87 &iio_dev_attr_in0_raw.dev_attr.attr,
88 &iio_dev_attr_in1_raw.dev_attr.attr,
89 &iio_dev_attr_in_scale.dev_attr.attr,
90 &iio_dev_attr_name.dev_attr.attr,
94 static mode_t ad7887_attr_is_visible(struct kobject *kobj,
95 struct attribute *attr, int n)
97 struct device *dev = container_of(kobj, struct device, kobj);
98 struct iio_dev *dev_info = dev_get_drvdata(dev);
99 struct ad7887_state *st = iio_dev_get_devdata(dev_info);
101 mode_t mode = attr->mode;
103 if ((attr == &iio_dev_attr_in1_raw.dev_attr.attr) && !st->en_dual)
109 static const struct attribute_group ad7887_attribute_group = {
110 .attrs = ad7887_attributes,
111 .is_visible = ad7887_attr_is_visible,
114 static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
116 * More devices added in future
122 .sign = IIO_SCAN_EL_TYPE_UNSIGNED,
127 static int __devinit ad7887_probe(struct spi_device *spi)
129 struct ad7887_platform_data *pdata = spi->dev.platform_data;
130 struct ad7887_state *st;
131 int ret, voltage_uv = 0;
133 st = kzalloc(sizeof(*st), GFP_KERNEL);
139 st->reg = regulator_get(&spi->dev, "vcc");
140 if (!IS_ERR(st->reg)) {
141 ret = regulator_enable(st->reg);
145 voltage_uv = regulator_get_voltage(st->reg);
149 &ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
151 spi_set_drvdata(spi, st);
153 atomic_set(&st->protect_ring, 0);
156 st->indio_dev = iio_allocate_device();
157 if (st->indio_dev == NULL) {
159 goto error_disable_reg;
162 /* Estabilish that the iio_dev is a child of the spi device */
163 st->indio_dev->dev.parent = &spi->dev;
164 st->indio_dev->attrs = &ad7887_attribute_group;
165 st->indio_dev->dev_data = (void *)(st);
166 st->indio_dev->driver_module = THIS_MODULE;
167 st->indio_dev->modes = INDIO_DIRECT_MODE;
169 /* Setup default message */
171 st->tx_cmd_buf[0] = AD7887_CH_AIN0 | AD7887_PM_MODE4 |
172 ((pdata && pdata->use_onchip_ref) ?
175 st->xfer[0].rx_buf = &st->data[0];
176 st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
179 spi_message_init(&st->msg[AD7887_CH0]);
180 spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);
182 if (pdata && pdata->en_dual) {
183 st->tx_cmd_buf[0] |= AD7887_DUAL | AD7887_REF_DIS;
185 st->tx_cmd_buf[2] = AD7887_CH_AIN1 | AD7887_DUAL |
186 AD7887_REF_DIS | AD7887_PM_MODE4;
187 st->tx_cmd_buf[4] = AD7887_CH_AIN0 | AD7887_DUAL |
188 AD7887_REF_DIS | AD7887_PM_MODE4;
189 st->tx_cmd_buf[6] = AD7887_CH_AIN1 | AD7887_DUAL |
190 AD7887_REF_DIS | AD7887_PM_MODE4;
192 st->xfer[1].rx_buf = &st->data[0];
193 st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
196 st->xfer[2].rx_buf = &st->data[2];
197 st->xfer[2].tx_buf = &st->tx_cmd_buf[4];
200 spi_message_init(&st->msg[AD7887_CH0_CH1]);
201 spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
202 spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);
204 st->xfer[3].rx_buf = &st->data[0];
205 st->xfer[3].tx_buf = &st->tx_cmd_buf[6];
208 spi_message_init(&st->msg[AD7887_CH1]);
209 spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);
213 if (pdata && pdata->vref_mv)
214 st->int_vref_mv = pdata->vref_mv;
216 st->int_vref_mv = voltage_uv / 1000;
218 dev_warn(&spi->dev, "reference voltage unspecified\n");
221 if (pdata && pdata->vref_mv)
222 st->int_vref_mv = pdata->vref_mv;
223 else if (pdata && pdata->use_onchip_ref)
224 st->int_vref_mv = st->chip_info->int_vref_mv;
226 dev_warn(&spi->dev, "reference voltage unspecified\n");
230 ret = ad7887_register_ring_funcs_and_init(st->indio_dev);
232 goto error_free_device;
234 ret = iio_device_register(st->indio_dev);
236 goto error_free_device;
238 ret = iio_ring_buffer_register(st->indio_dev->ring, 0);
240 goto error_cleanup_ring;
244 ad7887_ring_cleanup(st->indio_dev);
245 iio_device_unregister(st->indio_dev);
247 iio_free_device(st->indio_dev);
249 if (!IS_ERR(st->reg))
250 regulator_disable(st->reg);
252 if (!IS_ERR(st->reg))
253 regulator_put(st->reg);
259 static int ad7887_remove(struct spi_device *spi)
261 struct ad7887_state *st = spi_get_drvdata(spi);
262 struct iio_dev *indio_dev = st->indio_dev;
263 iio_ring_buffer_unregister(indio_dev->ring);
264 ad7887_ring_cleanup(indio_dev);
265 iio_device_unregister(indio_dev);
266 if (!IS_ERR(st->reg)) {
267 regulator_disable(st->reg);
268 regulator_put(st->reg);
274 static const struct spi_device_id ad7887_id[] = {
275 {"ad7887", ID_AD7887},
279 static struct spi_driver ad7887_driver = {
282 .bus = &spi_bus_type,
283 .owner = THIS_MODULE,
285 .probe = ad7887_probe,
286 .remove = __devexit_p(ad7887_remove),
287 .id_table = ad7887_id,
290 static int __init ad7887_init(void)
292 return spi_register_driver(&ad7887_driver);
294 module_init(ad7887_init);
296 static void __exit ad7887_exit(void)
298 spi_unregister_driver(&ad7887_driver);
300 module_exit(ad7887_exit);
302 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
303 MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
304 MODULE_LICENSE("GPL v2");
305 MODULE_ALIAS("spi:ad7887");