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