2 * AD7887 SPI ADC driver
4 * Copyright 2010-2011 Analog Devices Inc.
6 * Licensed under the GPL-2.
9 #include <linux/device.h>
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/sysfs.h>
13 #include <linux/spi/spi.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/err.h>
16 #include <linux/module.h>
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 #include <linux/iio/buffer.h>
25 static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
27 int ret = spi_sync(st->spi, &st->msg[ch]);
31 return (st->data[(ch * 2)] << 8) | st->data[(ch * 2) + 1];
34 static int ad7887_read_raw(struct iio_dev *indio_dev,
35 struct iio_chan_spec const *chan,
41 struct ad7887_state *st = iio_priv(indio_dev);
42 unsigned int scale_uv;
45 case IIO_CHAN_INFO_RAW:
46 mutex_lock(&indio_dev->mlock);
47 if (iio_buffer_enabled(indio_dev))
50 ret = ad7887_scan_direct(st, chan->address);
51 mutex_unlock(&indio_dev->mlock);
55 *val = (ret >> st->chip_info->channel[0].scan_type.shift) &
56 RES_MASK(st->chip_info->channel[0].scan_type.realbits);
58 case IIO_CHAN_INFO_SCALE:
59 scale_uv = (st->int_vref_mv * 1000)
60 >> st->chip_info->channel[0].scan_type.realbits;
62 *val2 = (scale_uv%1000)*1000;
63 return IIO_VAL_INT_PLUS_MICRO;
69 static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
71 * More devices added in future
78 .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
79 IIO_CHAN_INFO_SCALE_SHARED_BIT,
82 .scan_type = IIO_ST('u', 12, 16, 0),
88 .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
89 IIO_CHAN_INFO_SCALE_SHARED_BIT,
92 .scan_type = IIO_ST('u', 12, 16, 0),
94 .channel[2] = IIO_CHAN_SOFT_TIMESTAMP(2),
99 static const struct iio_info ad7887_info = {
100 .read_raw = &ad7887_read_raw,
101 .driver_module = THIS_MODULE,
104 static int __devinit ad7887_probe(struct spi_device *spi)
106 struct ad7887_platform_data *pdata = spi->dev.platform_data;
107 struct ad7887_state *st;
108 int ret, voltage_uv = 0;
109 struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st));
111 if (indio_dev == NULL)
114 st = iio_priv(indio_dev);
116 st->reg = regulator_get(&spi->dev, "vcc");
117 if (!IS_ERR(st->reg)) {
118 ret = regulator_enable(st->reg);
122 voltage_uv = regulator_get_voltage(st->reg);
126 &ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
128 spi_set_drvdata(spi, indio_dev);
131 /* Estabilish that the iio_dev is a child of the spi device */
132 indio_dev->dev.parent = &spi->dev;
133 indio_dev->name = spi_get_device_id(spi)->name;
134 indio_dev->info = &ad7887_info;
135 indio_dev->modes = INDIO_DIRECT_MODE;
137 /* Setup default message */
139 st->tx_cmd_buf[0] = AD7887_CH_AIN0 | AD7887_PM_MODE4 |
140 ((pdata && pdata->use_onchip_ref) ?
143 st->xfer[0].rx_buf = &st->data[0];
144 st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
147 spi_message_init(&st->msg[AD7887_CH0]);
148 spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);
150 if (pdata && pdata->en_dual) {
151 st->tx_cmd_buf[0] |= AD7887_DUAL | AD7887_REF_DIS;
153 st->tx_cmd_buf[2] = AD7887_CH_AIN1 | AD7887_DUAL |
154 AD7887_REF_DIS | AD7887_PM_MODE4;
155 st->tx_cmd_buf[4] = AD7887_CH_AIN0 | AD7887_DUAL |
156 AD7887_REF_DIS | AD7887_PM_MODE4;
157 st->tx_cmd_buf[6] = AD7887_CH_AIN1 | AD7887_DUAL |
158 AD7887_REF_DIS | AD7887_PM_MODE4;
160 st->xfer[1].rx_buf = &st->data[0];
161 st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
164 st->xfer[2].rx_buf = &st->data[2];
165 st->xfer[2].tx_buf = &st->tx_cmd_buf[4];
168 spi_message_init(&st->msg[AD7887_CH0_CH1]);
169 spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
170 spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);
172 st->xfer[3].rx_buf = &st->data[0];
173 st->xfer[3].tx_buf = &st->tx_cmd_buf[6];
176 spi_message_init(&st->msg[AD7887_CH1]);
177 spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);
179 if (pdata && pdata->vref_mv)
180 st->int_vref_mv = pdata->vref_mv;
182 st->int_vref_mv = voltage_uv / 1000;
184 dev_warn(&spi->dev, "reference voltage unspecified\n");
186 indio_dev->channels = st->chip_info->channel;
187 indio_dev->num_channels = 3;
189 if (pdata && pdata->vref_mv)
190 st->int_vref_mv = pdata->vref_mv;
191 else if (pdata && pdata->use_onchip_ref)
192 st->int_vref_mv = st->chip_info->int_vref_mv;
194 dev_warn(&spi->dev, "reference voltage unspecified\n");
196 indio_dev->channels = &st->chip_info->channel[1];
197 indio_dev->num_channels = 2;
200 ret = ad7887_register_ring_funcs_and_init(indio_dev);
202 goto error_disable_reg;
204 ret = iio_buffer_register(indio_dev,
206 indio_dev->num_channels);
208 goto error_cleanup_ring;
210 ret = iio_device_register(indio_dev);
212 goto error_unregister_ring;
215 error_unregister_ring:
216 iio_buffer_unregister(indio_dev);
218 ad7887_ring_cleanup(indio_dev);
220 if (!IS_ERR(st->reg))
221 regulator_disable(st->reg);
223 if (!IS_ERR(st->reg))
224 regulator_put(st->reg);
225 iio_device_free(indio_dev);
230 static int ad7887_remove(struct spi_device *spi)
232 struct iio_dev *indio_dev = spi_get_drvdata(spi);
233 struct ad7887_state *st = iio_priv(indio_dev);
235 iio_device_unregister(indio_dev);
236 iio_buffer_unregister(indio_dev);
237 ad7887_ring_cleanup(indio_dev);
238 if (!IS_ERR(st->reg)) {
239 regulator_disable(st->reg);
240 regulator_put(st->reg);
242 iio_device_free(indio_dev);
247 static const struct spi_device_id ad7887_id[] = {
248 {"ad7887", ID_AD7887},
251 MODULE_DEVICE_TABLE(spi, ad7887_id);
253 static struct spi_driver ad7887_driver = {
256 .owner = THIS_MODULE,
258 .probe = ad7887_probe,
259 .remove = __devexit_p(ad7887_remove),
260 .id_table = ad7887_id,
262 module_spi_driver(ad7887_driver);
264 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
265 MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
266 MODULE_LICENSE("GPL v2");