/* * AD7887 SPI ADC driver * * Copyright 2010-2011 Analog Devices Inc. * * Licensed under the GPL-2. */ #include #include #include #include #include #include #include #include "../iio.h" #include "../sysfs.h" #include "../ring_generic.h" #include "adc.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 *dev_info, struct iio_chan_spec const *chan, int *val, int *val2, long m) { int ret; struct ad7887_state *st = iio_priv(dev_info); unsigned int scale_uv; switch (m) { case 0: mutex_lock(&dev_info->mlock); if (iio_ring_enabled(dev_info)) ret = ad7887_scan_from_ring(st, 1 << chan->address); else ret = ad7887_scan_direct(st, chan->address); mutex_unlock(&dev_info->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] = IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 1, 0, (1 << IIO_CHAN_INFO_SCALE_SHARED), 1, 1, IIO_ST('u', 12, 16, 0), 0), .channel[1] = IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 0, 0, (1 << IIO_CHAN_INFO_SCALE_SHARED), 0, 0, IIO_ST('u', 12, 16, 0), 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, regdone = 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_device_register(indio_dev); if (ret) goto error_disable_reg; regdone = 1; ret = iio_ring_buffer_register_ex(indio_dev->ring, 0, indio_dev->channels, indio_dev->num_channels); if (ret) goto error_cleanup_ring; return 0; 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); if (regdone) iio_device_unregister(indio_dev); else 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_ring_buffer_unregister(indio_dev->ring); ad7887_ring_cleanup(indio_dev); if (!IS_ERR(st->reg)) { regulator_disable(st->reg); regulator_put(st->reg); } iio_device_unregister(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 "); MODULE_DESCRIPTION("Analog Devices AD7887 ADC"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("spi:ad7887");