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..5d85efab658c
--- /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.%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");