diff options
Diffstat (limited to 'drivers/staging/iio/adc/ad7887_core.c')
-rw-r--r-- | drivers/staging/iio/adc/ad7887_core.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/drivers/staging/iio/adc/ad7887_core.c b/drivers/staging/iio/adc/ad7887_core.c new file mode 100644 index 000000000000..685908995d49 --- /dev/null +++ b/drivers/staging/iio/adc/ad7887_core.c @@ -0,0 +1,305 @@ +/* + * 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.%d\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"); |