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Diffstat (limited to 'drivers/iio/dac/max517.c')
-rw-r--r--drivers/iio/dac/max517.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/iio/dac/max517.c b/drivers/iio/dac/max517.c
new file mode 100644
index 0000000000..685980184d
--- /dev/null
+++ b/drivers/iio/dac/max517.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * max517.c - Support for Maxim MAX517, MAX518 and MAX519
+ *
+ * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
+ */
+
+#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;
+}
+
+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 DEFINE_SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume);
+
+static const struct iio_info max517_info = {
+ .read_raw = max517_read_raw,
+ .write_raw = max517_write_raw,
+};
+
+#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 = i2c_client_get_device_id(client);
+ 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);
+ data->client = client;
+
+ 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 devm_iio_device_register(&client->dev, indio_dev);
+}
+
+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 = pm_sleep_ptr(&max517_pm_ops),
+ },
+ .probe = max517_probe,
+ .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");