| /* |
| * AD7298 SPI ADC driver |
| * |
| * Copyright 2011 Analog Devices Inc. |
| * |
| * Licensed under the GPL-2. |
| */ |
| |
| #include <linux/workqueue.h> |
| #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 "../iio.h" |
| #include "../sysfs.h" |
| #include "../ring_generic.h" |
| #include "adc.h" |
| |
| #include "ad7298.h" |
| |
| 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 ssize_t ad7298_scan(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct iio_dev *dev_info = dev_get_drvdata(dev); |
| struct ad7298_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 = ad7298_scan_from_ring(st, this_attr->address); |
| else |
| ret = ad7298_scan_direct(st, this_attr->address); |
| mutex_unlock(&dev_info->mlock); |
| |
| if (ret < 0) |
| return ret; |
| |
| return sprintf(buf, "%d\n", ret & RES_MASK(AD7298_BITS)); |
| } |
| |
| static IIO_DEV_ATTR_IN_RAW(0, ad7298_scan, 0); |
| static IIO_DEV_ATTR_IN_RAW(1, ad7298_scan, 1); |
| static IIO_DEV_ATTR_IN_RAW(2, ad7298_scan, 2); |
| static IIO_DEV_ATTR_IN_RAW(3, ad7298_scan, 3); |
| static IIO_DEV_ATTR_IN_RAW(4, ad7298_scan, 4); |
| static IIO_DEV_ATTR_IN_RAW(5, ad7298_scan, 5); |
| static IIO_DEV_ATTR_IN_RAW(6, ad7298_scan, 6); |
| static IIO_DEV_ATTR_IN_RAW(7, ad7298_scan, 7); |
| |
| static ssize_t ad7298_show_temp(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct iio_dev *dev_info = dev_get_drvdata(dev); |
| struct ad7298_state *st = iio_dev_get_devdata(dev_info); |
| int tmp; |
| |
| tmp = cpu_to_be16(AD7298_WRITE | AD7298_TSENSE | |
| AD7298_TAVG | st->ext_ref); |
| |
| mutex_lock(&dev_info->mlock); |
| spi_write(st->spi, (u8 *)&tmp, 2); |
| tmp = 0; |
| spi_write(st->spi, (u8 *)&tmp, 2); |
| usleep_range(101, 1000); /* sleep > 100us */ |
| spi_read(st->spi, (u8 *)&tmp, 2); |
| mutex_unlock(&dev_info->mlock); |
| |
| tmp = be16_to_cpu(tmp) & 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 */ |
| } |
| |
| return sprintf(buf, "%d\n", tmp); |
| } |
| |
| static IIO_DEVICE_ATTR(temp0_input, S_IRUGO, ad7298_show_temp, NULL, 0); |
| |
| static ssize_t ad7298_show_scale(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct iio_dev *dev_info = dev_get_drvdata(dev); |
| struct ad7298_state *st = iio_dev_get_devdata(dev_info); |
| /* Corresponds to Vref / 2^(bits) */ |
| unsigned int scale_uv = (st->int_vref_mv * 1000) >> AD7298_BITS; |
| |
| return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000); |
| } |
| static IIO_DEVICE_ATTR(in_scale, S_IRUGO, ad7298_show_scale, NULL, 0); |
| |
| static ssize_t ad7298_show_name(struct device *dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct iio_dev *dev_info = dev_get_drvdata(dev); |
| struct ad7298_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, ad7298_show_name, NULL, 0); |
| |
| static struct attribute *ad7298_attributes[] = { |
| &iio_dev_attr_in0_raw.dev_attr.attr, |
| &iio_dev_attr_in1_raw.dev_attr.attr, |
| &iio_dev_attr_in2_raw.dev_attr.attr, |
| &iio_dev_attr_in3_raw.dev_attr.attr, |
| &iio_dev_attr_in4_raw.dev_attr.attr, |
| &iio_dev_attr_in5_raw.dev_attr.attr, |
| &iio_dev_attr_in6_raw.dev_attr.attr, |
| &iio_dev_attr_in7_raw.dev_attr.attr, |
| &iio_dev_attr_in_scale.dev_attr.attr, |
| &iio_dev_attr_temp0_input.dev_attr.attr, |
| &iio_dev_attr_name.dev_attr.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group ad7298_attribute_group = { |
| .attrs = ad7298_attributes, |
| }; |
| |
| static int __devinit ad7298_probe(struct spi_device *spi) |
| { |
| struct ad7298_platform_data *pdata = spi->dev.platform_data; |
| struct ad7298_state *st; |
| int ret; |
| |
| 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; |
| } |
| |
| 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; |
| } |
| |
| st->indio_dev->dev.parent = &spi->dev; |
| st->indio_dev->attrs = &ad7298_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->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(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: |
| ad7298_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 __devexit ad7298_remove(struct spi_device *spi) |
| { |
| struct ad7298_state *st = spi_get_drvdata(spi); |
| struct iio_dev *indio_dev = st->indio_dev; |
| |
| iio_ring_buffer_unregister(indio_dev->ring); |
| ad7298_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 ad7298_id[] = { |
| {"ad7298", 0}, |
| {} |
| }; |
| |
| static struct spi_driver ad7298_driver = { |
| .driver = { |
| .name = "ad7298", |
| .bus = &spi_bus_type, |
| .owner = THIS_MODULE, |
| }, |
| .probe = ad7298_probe, |
| .remove = __devexit_p(ad7298_remove), |
| .id_table = ad7298_id, |
| }; |
| |
| static int __init ad7298_init(void) |
| { |
| return spi_register_driver(&ad7298_driver); |
| } |
| module_init(ad7298_init); |
| |
| static void __exit ad7298_exit(void) |
| { |
| spi_unregister_driver(&ad7298_driver); |
| } |
| module_exit(ad7298_exit); |
| |
| MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); |
| MODULE_DESCRIPTION("Analog Devices AD7298 ADC"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_ALIAS("spi:ad7298"); |