--- /dev/null
+/*
+ * 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");
projects / mv-sheeva.git / blobdiff