268 lines
6.4 KiB
C
268 lines
6.4 KiB
C
/*
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* AD7887 SPI ADC driver
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*
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* Copyright 2010-2011 Analog Devices Inc.
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*
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* Licensed under the GPL-2.
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*/
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include <linux/spi/spi.h>
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#include <linux/regulator/consumer.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include "../iio.h"
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#include "../sysfs.h"
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#include "../ring_generic.h"
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#include "ad7887.h"
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static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
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{
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int ret = spi_sync(st->spi, &st->msg[ch]);
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if (ret)
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return ret;
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return (st->data[(ch * 2)] << 8) | st->data[(ch * 2) + 1];
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}
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static int ad7887_read_raw(struct iio_dev *dev_info,
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struct iio_chan_spec const *chan,
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int *val,
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int *val2,
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long m)
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{
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int ret;
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struct ad7887_state *st = iio_priv(dev_info);
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unsigned int scale_uv;
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switch (m) {
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case 0:
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mutex_lock(&dev_info->mlock);
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if (iio_ring_enabled(dev_info))
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ret = ad7887_scan_from_ring(st, 1 << chan->address);
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else
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ret = ad7887_scan_direct(st, chan->address);
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mutex_unlock(&dev_info->mlock);
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if (ret < 0)
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return ret;
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*val = (ret >> st->chip_info->channel[0].scan_type.shift) &
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RES_MASK(st->chip_info->channel[0].scan_type.realbits);
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return IIO_VAL_INT;
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case (1 << IIO_CHAN_INFO_SCALE_SHARED):
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scale_uv = (st->int_vref_mv * 1000)
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>> st->chip_info->channel[0].scan_type.realbits;
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*val = scale_uv/1000;
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*val2 = (scale_uv%1000)*1000;
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return IIO_VAL_INT_PLUS_MICRO;
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}
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return -EINVAL;
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}
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static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
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/*
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* More devices added in future
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*/
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[ID_AD7887] = {
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.channel[0] = IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 1, 0,
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(1 << IIO_CHAN_INFO_SCALE_SHARED),
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1, 1, IIO_ST('u', 12, 16, 0), 0),
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.channel[1] = IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 0, 0,
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(1 << IIO_CHAN_INFO_SCALE_SHARED),
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0, 0, IIO_ST('u', 12, 16, 0), 0),
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.channel[2] = IIO_CHAN_SOFT_TIMESTAMP(2),
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.int_vref_mv = 2500,
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},
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};
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static const struct iio_info ad7887_info = {
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.read_raw = &ad7887_read_raw,
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.driver_module = THIS_MODULE,
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};
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static int __devinit ad7887_probe(struct spi_device *spi)
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{
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struct ad7887_platform_data *pdata = spi->dev.platform_data;
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struct ad7887_state *st;
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int ret, voltage_uv = 0, regdone = 0;
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struct iio_dev *indio_dev = iio_allocate_device(sizeof(*st));
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if (indio_dev == NULL)
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return -ENOMEM;
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st = iio_priv(indio_dev);
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st->reg = regulator_get(&spi->dev, "vcc");
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if (!IS_ERR(st->reg)) {
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ret = regulator_enable(st->reg);
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if (ret)
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goto error_put_reg;
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voltage_uv = regulator_get_voltage(st->reg);
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}
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st->chip_info =
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&ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
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spi_set_drvdata(spi, indio_dev);
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st->spi = spi;
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/* Estabilish that the iio_dev is a child of the spi device */
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indio_dev->dev.parent = &spi->dev;
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indio_dev->name = spi_get_device_id(spi)->name;
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indio_dev->info = &ad7887_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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/* Setup default message */
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st->tx_cmd_buf[0] = AD7887_CH_AIN0 | AD7887_PM_MODE4 |
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((pdata && pdata->use_onchip_ref) ?
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0 : AD7887_REF_DIS);
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st->xfer[0].rx_buf = &st->data[0];
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st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
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st->xfer[0].len = 2;
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spi_message_init(&st->msg[AD7887_CH0]);
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spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);
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if (pdata && pdata->en_dual) {
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st->tx_cmd_buf[0] |= AD7887_DUAL | AD7887_REF_DIS;
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st->tx_cmd_buf[2] = AD7887_CH_AIN1 | AD7887_DUAL |
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AD7887_REF_DIS | AD7887_PM_MODE4;
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st->tx_cmd_buf[4] = AD7887_CH_AIN0 | AD7887_DUAL |
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AD7887_REF_DIS | AD7887_PM_MODE4;
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st->tx_cmd_buf[6] = AD7887_CH_AIN1 | AD7887_DUAL |
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AD7887_REF_DIS | AD7887_PM_MODE4;
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st->xfer[1].rx_buf = &st->data[0];
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st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
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st->xfer[1].len = 2;
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st->xfer[2].rx_buf = &st->data[2];
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st->xfer[2].tx_buf = &st->tx_cmd_buf[4];
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st->xfer[2].len = 2;
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spi_message_init(&st->msg[AD7887_CH0_CH1]);
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spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
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spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);
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st->xfer[3].rx_buf = &st->data[0];
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st->xfer[3].tx_buf = &st->tx_cmd_buf[6];
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st->xfer[3].len = 2;
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spi_message_init(&st->msg[AD7887_CH1]);
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spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);
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if (pdata && pdata->vref_mv)
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st->int_vref_mv = pdata->vref_mv;
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else if (voltage_uv)
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st->int_vref_mv = voltage_uv / 1000;
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else
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dev_warn(&spi->dev, "reference voltage unspecified\n");
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indio_dev->channels = st->chip_info->channel;
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indio_dev->num_channels = 3;
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} else {
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if (pdata && pdata->vref_mv)
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st->int_vref_mv = pdata->vref_mv;
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else if (pdata && pdata->use_onchip_ref)
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st->int_vref_mv = st->chip_info->int_vref_mv;
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else
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dev_warn(&spi->dev, "reference voltage unspecified\n");
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indio_dev->channels = &st->chip_info->channel[1];
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indio_dev->num_channels = 2;
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}
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ret = ad7887_register_ring_funcs_and_init(indio_dev);
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if (ret)
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goto error_disable_reg;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_disable_reg;
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regdone = 1;
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ret = iio_ring_buffer_register(indio_dev,
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indio_dev->channels,
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indio_dev->num_channels);
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if (ret)
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goto error_cleanup_ring;
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return 0;
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error_cleanup_ring:
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ad7887_ring_cleanup(indio_dev);
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error_disable_reg:
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if (!IS_ERR(st->reg))
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regulator_disable(st->reg);
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error_put_reg:
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if (!IS_ERR(st->reg))
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regulator_put(st->reg);
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if (regdone)
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iio_device_unregister(indio_dev);
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else
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iio_free_device(indio_dev);
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return ret;
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}
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static int ad7887_remove(struct spi_device *spi)
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{
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struct iio_dev *indio_dev = spi_get_drvdata(spi);
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struct ad7887_state *st = iio_priv(indio_dev);
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iio_ring_buffer_unregister(indio_dev);
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ad7887_ring_cleanup(indio_dev);
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if (!IS_ERR(st->reg)) {
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regulator_disable(st->reg);
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regulator_put(st->reg);
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}
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iio_device_unregister(indio_dev);
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return 0;
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}
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static const struct spi_device_id ad7887_id[] = {
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{"ad7887", ID_AD7887},
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{}
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};
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static struct spi_driver ad7887_driver = {
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.driver = {
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.name = "ad7887",
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.bus = &spi_bus_type,
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.owner = THIS_MODULE,
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},
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.probe = ad7887_probe,
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.remove = __devexit_p(ad7887_remove),
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.id_table = ad7887_id,
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};
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static int __init ad7887_init(void)
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{
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return spi_register_driver(&ad7887_driver);
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}
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module_init(ad7887_init);
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static void __exit ad7887_exit(void)
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{
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spi_unregister_driver(&ad7887_driver);
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}
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module_exit(ad7887_exit);
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MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
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MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("spi:ad7887");
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