| /* |
| * AD7298 SPI ADC driver |
| * |
| * Copyright 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/delay.h> |
| #include <linux/module.h> |
| |
| #include <linux/iio/iio.h> |
| #include <linux/iio/sysfs.h> |
| #include <linux/iio/buffer.h> |
| |
| #include "ad7298.h" |
| |
| #define AD7298_V_CHAN(index) \ |
| { \ |
| .type = IIO_VOLTAGE, \ |
| .indexed = 1, \ |
| .channel = index, \ |
| .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ |
| IIO_CHAN_INFO_SCALE_SHARED_BIT, \ |
| .address = index, \ |
| .scan_index = index, \ |
| .scan_type = { \ |
| .sign = 'u', \ |
| .realbits = 12, \ |
| .storagebits = 16, \ |
| }, \ |
| } |
| |
| static const struct iio_chan_spec ad7298_channels[] = { |
| { |
| .type = IIO_TEMP, |
| .indexed = 1, |
| .channel = 0, |
| .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | |
| IIO_CHAN_INFO_SCALE_SEPARATE_BIT, |
| .address = AD7298_CH_TEMP, |
| .scan_index = -1, |
| .scan_type = { |
| .sign = 's', |
| .realbits = 32, |
| .storagebits = 32, |
| }, |
| }, |
| AD7298_V_CHAN(0), |
| AD7298_V_CHAN(1), |
| AD7298_V_CHAN(2), |
| AD7298_V_CHAN(3), |
| AD7298_V_CHAN(4), |
| AD7298_V_CHAN(5), |
| AD7298_V_CHAN(6), |
| AD7298_V_CHAN(7), |
| IIO_CHAN_SOFT_TIMESTAMP(8), |
| }; |
| |
| static int ad7298_scan_direct(struct ad7298_state *st, unsigned ch) |
| { |
| int ret; |
| st->tx_buf[0] = cpu_to_be16(AD7298_WRITE | st->ext_ref | |
| (AD7298_CH(0) >> ch)); |
| |
| ret = spi_sync(st->spi, &st->scan_single_msg); |
| if (ret) |
| return ret; |
| |
| return be16_to_cpu(st->rx_buf[0]); |
| } |
| |
| static int ad7298_scan_temp(struct ad7298_state *st, int *val) |
| { |
| int tmp, ret; |
| __be16 buf; |
| |
| buf = cpu_to_be16(AD7298_WRITE | AD7298_TSENSE | |
| AD7298_TAVG | st->ext_ref); |
| |
| ret = spi_write(st->spi, (u8 *)&buf, 2); |
| if (ret) |
| return ret; |
| |
| buf = cpu_to_be16(0); |
| |
| ret = spi_write(st->spi, (u8 *)&buf, 2); |
| if (ret) |
| return ret; |
| |
| usleep_range(101, 1000); /* sleep > 100us */ |
| |
| ret = spi_read(st->spi, (u8 *)&buf, 2); |
| if (ret) |
| return ret; |
| |
| tmp = be16_to_cpu(buf) & RES_MASK(AD7298_BITS); |
| |
| /* |
| * One LSB of the ADC corresponds to 0.25 deg C. |
| * The temperature reading is in 12-bit twos complement format |
| */ |
| |
| if (tmp & (1 << (AD7298_BITS - 1))) { |
| tmp = (4096 - tmp) * 250; |
| tmp -= (2 * tmp); |
| |
| } else { |
| tmp *= 250; /* temperature in milli degrees Celsius */ |
| } |
| |
| *val = tmp; |
| |
| return 0; |
| } |
| |
| static int ad7298_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, |
| int *val2, |
| long m) |
| { |
| int ret; |
| struct ad7298_state *st = iio_priv(indio_dev); |
| unsigned int scale_uv; |
| |
| switch (m) { |
| case IIO_CHAN_INFO_RAW: |
| mutex_lock(&indio_dev->mlock); |
| if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) { |
| ret = -EBUSY; |
| } else { |
| if (chan->address == AD7298_CH_TEMP) |
| ret = ad7298_scan_temp(st, val); |
| else |
| ret = ad7298_scan_direct(st, chan->address); |
| } |
| mutex_unlock(&indio_dev->mlock); |
| |
| if (ret < 0) |
| return ret; |
| |
| if (chan->address != AD7298_CH_TEMP) |
| *val = ret & RES_MASK(AD7298_BITS); |
| |
| return IIO_VAL_INT; |
| case IIO_CHAN_INFO_SCALE: |
| switch (chan->type) { |
| case IIO_VOLTAGE: |
| scale_uv = (st->int_vref_mv * 1000) >> AD7298_BITS; |
| *val = scale_uv / 1000; |
| *val2 = (scale_uv % 1000) * 1000; |
| return IIO_VAL_INT_PLUS_MICRO; |
| case IIO_TEMP: |
| *val = 1; |
| *val2 = 0; |
| return IIO_VAL_INT_PLUS_MICRO; |
| default: |
| return -EINVAL; |
| } |
| } |
| return -EINVAL; |
| } |
| |
| static const struct iio_info ad7298_info = { |
| .read_raw = &ad7298_read_raw, |
| .update_scan_mode = ad7298_update_scan_mode, |
| .driver_module = THIS_MODULE, |
| }; |
| |
| static int __devinit ad7298_probe(struct spi_device *spi) |
| { |
| struct ad7298_platform_data *pdata = spi->dev.platform_data; |
| struct ad7298_state *st; |
| int ret; |
| struct iio_dev *indio_dev = iio_device_alloc(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; |
| } |
| |
| spi_set_drvdata(spi, indio_dev); |
| |
| st->spi = spi; |
| |
| indio_dev->name = spi_get_device_id(spi)->name; |
| indio_dev->dev.parent = &spi->dev; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->channels = ad7298_channels; |
| indio_dev->num_channels = ARRAY_SIZE(ad7298_channels); |
| indio_dev->info = &ad7298_info; |
| |
| /* Setup default message */ |
| |
| st->scan_single_xfer[0].tx_buf = &st->tx_buf[0]; |
| st->scan_single_xfer[0].len = 2; |
| st->scan_single_xfer[0].cs_change = 1; |
| st->scan_single_xfer[1].tx_buf = &st->tx_buf[1]; |
| st->scan_single_xfer[1].len = 2; |
| st->scan_single_xfer[1].cs_change = 1; |
| st->scan_single_xfer[2].rx_buf = &st->rx_buf[0]; |
| st->scan_single_xfer[2].len = 2; |
| |
| spi_message_init(&st->scan_single_msg); |
| spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg); |
| spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg); |
| spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg); |
| |
| if (pdata && pdata->vref_mv) { |
| st->int_vref_mv = pdata->vref_mv; |
| st->ext_ref = AD7298_EXTREF; |
| } else { |
| st->int_vref_mv = AD7298_INTREF_mV; |
| } |
| |
| ret = ad7298_register_ring_funcs_and_init(indio_dev); |
| if (ret) |
| goto error_disable_reg; |
| |
| ret = iio_device_register(indio_dev); |
| if (ret) |
| goto error_cleanup_ring; |
| |
| return 0; |
| |
| error_cleanup_ring: |
| ad7298_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_device_free(indio_dev); |
| |
| return ret; |
| } |
| |
| static int __devexit ad7298_remove(struct spi_device *spi) |
| { |
| struct iio_dev *indio_dev = spi_get_drvdata(spi); |
| struct ad7298_state *st = iio_priv(indio_dev); |
| |
| iio_device_unregister(indio_dev); |
| ad7298_ring_cleanup(indio_dev); |
| if (!IS_ERR(st->reg)) { |
| regulator_disable(st->reg); |
| regulator_put(st->reg); |
| } |
| iio_device_free(indio_dev); |
| |
| return 0; |
| } |
| |
| static const struct spi_device_id ad7298_id[] = { |
| {"ad7298", 0}, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(spi, ad7298_id); |
| |
| static struct spi_driver ad7298_driver = { |
| .driver = { |
| .name = "ad7298", |
| .owner = THIS_MODULE, |
| }, |
| .probe = ad7298_probe, |
| .remove = __devexit_p(ad7298_remove), |
| .id_table = ad7298_id, |
| }; |
| module_spi_driver(ad7298_driver); |
| |
| MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); |
| MODULE_DESCRIPTION("Analog Devices AD7298 ADC"); |
| MODULE_LICENSE("GPL v2"); |