1 files changed, 287 insertions, 0 deletions

diff --git a/drivers/staging/iio/adc/ad7298_core.c b/drivers/staging/iio/adc/ad7298_core.c
new file mode 100644
index 000000000000..2e9154e7d887
--- /dev/null
+++ b/drivers/staging/iio/adc/ad7298_core.c
@@ -0,0 +1,287 @@
+/*
+ * 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");