Initial import

1 files changed, 243 insertions, 0 deletions

diff --git a/drivers/iio/dac/max517.c b/drivers/iio/dac/max517.c
new file mode 100644
index 000000000..5507b3970
--- /dev/null
+++ b/drivers/iio/dac/max517.c
@@ -0,0 +1,243 @@
+/*
+ *  max517.c - Support for Maxim MAX517, MAX518 and MAX519
+ *
+ *  Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/dac/max517.h>
+
+#define MAX517_DRV_NAME	"max517"
+
+/* Commands */
+#define COMMAND_CHANNEL0	0x00
+#define COMMAND_CHANNEL1	0x01 /* for MAX518 and MAX519 */
+#define COMMAND_PD		0x08 /* Power Down */
+
+enum max517_device_ids {
+	ID_MAX517,
+	ID_MAX518,
+	ID_MAX519,
+	ID_MAX520,
+	ID_MAX521,
+};
+
+struct max517_data {
+	struct i2c_client	*client;
+	unsigned short		vref_mv[8];
+};
+
+/*
+ * channel: bit 0: channel 1
+ *          bit 1: channel 2
+ * (this way, it's possible to set both channels at once)
+ */
+static int max517_set_value(struct iio_dev *indio_dev,
+	long val, int channel)
+{
+	struct max517_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+	u8 outbuf[2];
+	int res;
+
+	if (val < 0 || val > 255)
+		return -EINVAL;
+
+	outbuf[0] = channel;
+	outbuf[1] = val;
+
+	res = i2c_master_send(client, outbuf, 2);
+	if (res < 0)
+		return res;
+	else if (res != 2)
+		return -EIO;
+	else
+		return 0;
+}
+
+static int max517_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct max517_data *data = iio_priv(indio_dev);
+
+	switch (m) {
+	case IIO_CHAN_INFO_SCALE:
+		/* Corresponds to Vref / 2^(bits) */
+		*val = data->vref_mv[chan->channel];
+		*val2 = 8;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+static int max517_write_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int val, int val2, long mask)
+{
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = max517_set_value(indio_dev, val, chan->channel);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max517_suspend(struct device *dev)
+{
+	u8 outbuf = COMMAND_PD;
+
+	return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
+}
+
+static int max517_resume(struct device *dev)
+{
+	u8 outbuf = 0;
+
+	return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
+}
+
+static SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume);
+#define MAX517_PM_OPS (&max517_pm_ops)
+#else
+#define MAX517_PM_OPS NULL
+#endif
+
+static const struct iio_info max517_info = {
+	.read_raw = max517_read_raw,
+	.write_raw = max517_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+#define MAX517_CHANNEL(chan) {				\
+	.type = IIO_VOLTAGE,				\
+	.indexed = 1,					\
+	.output = 1,					\
+	.channel = (chan),				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+	BIT(IIO_CHAN_INFO_SCALE),			\
+}
+
+static const struct iio_chan_spec max517_channels[] = {
+	MAX517_CHANNEL(0),
+	MAX517_CHANNEL(1),
+	MAX517_CHANNEL(2),
+	MAX517_CHANNEL(3),
+	MAX517_CHANNEL(4),
+	MAX517_CHANNEL(5),
+	MAX517_CHANNEL(6),
+	MAX517_CHANNEL(7),
+};
+
+static int max517_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct max517_data *data;
+	struct iio_dev *indio_dev;
+	struct max517_platform_data *platform_data = client->dev.platform_data;
+	int chan;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	/* establish that the iio_dev is a child of the i2c device */
+	indio_dev->dev.parent = &client->dev;
+
+	switch (id->driver_data) {
+	case ID_MAX521:
+		indio_dev->num_channels = 8;
+		break;
+	case ID_MAX520:
+		indio_dev->num_channels = 4;
+		break;
+	case ID_MAX519:
+	case ID_MAX518:
+		indio_dev->num_channels = 2;
+		break;
+	default:  /* single channel for MAX517 */
+		indio_dev->num_channels = 1;
+		break;
+	}
+	indio_dev->channels = max517_channels;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &max517_info;
+
+	/*
+	 * Reference voltage on MAX518 and default is 5V, else take vref_mv
+	 * from platform_data
+	 */
+	for (chan = 0; chan < indio_dev->num_channels; chan++) {
+		if (id->driver_data == ID_MAX518 || !platform_data)
+			data->vref_mv[chan] = 5000; /* mV */
+		else
+			data->vref_mv[chan] = platform_data->vref_mv[chan];
+	}
+
+	return iio_device_register(indio_dev);
+}
+
+static int max517_remove(struct i2c_client *client)
+{
+	iio_device_unregister(i2c_get_clientdata(client));
+	return 0;
+}
+
+static const struct i2c_device_id max517_id[] = {
+	{ "max517", ID_MAX517 },
+	{ "max518", ID_MAX518 },
+	{ "max519", ID_MAX519 },
+	{ "max520", ID_MAX520 },
+	{ "max521", ID_MAX521 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max517_id);
+
+static struct i2c_driver max517_driver = {
+	.driver = {
+		.name	= MAX517_DRV_NAME,
+		.pm		= MAX517_PM_OPS,
+	},
+	.probe		= max517_probe,
+	.remove		= max517_remove,
+	.id_table	= max517_id,
+};
+module_i2c_driver(max517_driver);
+
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("MAX517/518/519/520/521 8-bit DAC");
+MODULE_LICENSE("GPL");