| /* |
| * AD7887 SPI ADC driver |
| * |
| * Copyright 2010 Analog Devices Inc. |
| * |
| * Licensed under the GPL-2 or later. |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/workqueue.h> |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/sysfs.h> |
| #include <linux/list.h> |
| #include <linux/spi/spi.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/err.h> |
| |
| #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 ssize_t ad7887_scan(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct iio_dev *dev_info = dev_get_drvdata(dev); |
| struct ad7887_state *st = dev_info->dev_data; |
| struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); |
| int ret; |
| |
| mutex_lock(&dev_info->mlock); |
| if (iio_ring_enabled(dev_info)) |
| ret = ad7887_scan_from_ring(st, 1 << this_attr->address); |
| else |
| ret = ad7887_scan_direct(st, this_attr->address); |
| mutex_unlock(&dev_info->mlock); |
| |
| if (ret < 0) |
| return ret; |
| |
| return sprintf(buf, "%d\n", (ret >> st->chip_info->left_shift) & |
| RES_MASK(st->chip_info->bits)); |
| } |
| static IIO_DEV_ATTR_IN_RAW(0, ad7887_scan, 0); |
| static IIO_DEV_ATTR_IN_RAW(1, ad7887_scan, 1); |
| |
| static ssize_t ad7887_show_scale(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| /* Driver currently only support internal vref */ |
| struct iio_dev *dev_info = dev_get_drvdata(dev); |
| struct ad7887_state *st = iio_dev_get_devdata(dev_info); |
| /* Corresponds to Vref / 2^(bits) */ |
| unsigned int scale_uv = (st->int_vref_mv * 1000) >> st->chip_info->bits; |
| |
| return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000); |
| } |
| static IIO_DEVICE_ATTR(in_scale, S_IRUGO, ad7887_show_scale, NULL, 0); |
| |
| static ssize_t ad7887_show_name(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct iio_dev *dev_info = dev_get_drvdata(dev); |
| struct ad7887_state *st = iio_dev_get_devdata(dev_info); |
| |
| return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name); |
| } |
| static IIO_DEVICE_ATTR(name, S_IRUGO, ad7887_show_name, NULL, 0); |
| |
| static struct attribute *ad7887_attributes[] = { |
| &iio_dev_attr_in0_raw.dev_attr.attr, |
| &iio_dev_attr_in1_raw.dev_attr.attr, |
| &iio_dev_attr_in_scale.dev_attr.attr, |
| &iio_dev_attr_name.dev_attr.attr, |
| NULL, |
| }; |
| |
| static mode_t ad7887_attr_is_visible(struct kobject *kobj, |
| struct attribute *attr, int n) |
| { |
| struct device *dev = container_of(kobj, struct device, kobj); |
| struct iio_dev *dev_info = dev_get_drvdata(dev); |
| struct ad7887_state *st = iio_dev_get_devdata(dev_info); |
| |
| mode_t mode = attr->mode; |
| |
| if ((attr == &iio_dev_attr_in1_raw.dev_attr.attr) && !st->en_dual) |
| mode = 0; |
| |
| return mode; |
| } |
| |
| static const struct attribute_group ad7887_attribute_group = { |
| .attrs = ad7887_attributes, |
| .is_visible = ad7887_attr_is_visible, |
| }; |
| |
| static const struct ad7887_chip_info ad7887_chip_info_tbl[] = { |
| /* |
| * More devices added in future |
| */ |
| [ID_AD7887] = { |
| .bits = 12, |
| .storagebits = 16, |
| .left_shift = 0, |
| .sign = IIO_SCAN_EL_TYPE_UNSIGNED, |
| .int_vref_mv = 2500, |
| }, |
| }; |
| |
| 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; |
| |
| st = kzalloc(sizeof(*st), GFP_KERNEL); |
| if (st == NULL) { |
| ret = -ENOMEM; |
| goto error_ret; |
| } |
| |
| 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, st); |
| |
| atomic_set(&st->protect_ring, 0); |
| st->spi = spi; |
| |
| st->indio_dev = iio_allocate_device(); |
| if (st->indio_dev == NULL) { |
| ret = -ENOMEM; |
| goto error_disable_reg; |
| } |
| |
| /* Estabilish that the iio_dev is a child of the spi device */ |
| st->indio_dev->dev.parent = &spi->dev; |
| st->indio_dev->attrs = &ad7887_attribute_group; |
| st->indio_dev->dev_data = (void *)(st); |
| st->indio_dev->driver_module = THIS_MODULE; |
| st->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]); |
| |
| st->en_dual = true; |
| |
| 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"); |
| |
| } 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"); |
| } |
| |
| |
| ret = ad7887_register_ring_funcs_and_init(st->indio_dev); |
| if (ret) |
| goto error_free_device; |
| |
| ret = iio_device_register(st->indio_dev); |
| if (ret) |
| goto error_free_device; |
| |
| ret = iio_ring_buffer_register(st->indio_dev->ring, 0); |
| if (ret) |
| goto error_cleanup_ring; |
| return 0; |
| |
| error_cleanup_ring: |
| ad7887_ring_cleanup(st->indio_dev); |
| iio_device_unregister(st->indio_dev); |
| error_free_device: |
| iio_free_device(st->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); |
| kfree(st); |
| error_ret: |
| return ret; |
| } |
| |
| static int ad7887_remove(struct spi_device *spi) |
| { |
| struct ad7887_state *st = spi_get_drvdata(spi); |
| struct iio_dev *indio_dev = st->indio_dev; |
| iio_ring_buffer_unregister(indio_dev->ring); |
| ad7887_ring_cleanup(indio_dev); |
| iio_device_unregister(indio_dev); |
| if (!IS_ERR(st->reg)) { |
| regulator_disable(st->reg); |
| regulator_put(st->reg); |
| } |
| kfree(st); |
| 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"); |