[PATCH 082/961] Staging: iio: add driver for MAX517/518/519
Greg Kroah-Hartman
gregkh at suse.de
Wed Mar 16 20:55:25 UTC 2011
From: Roland Stigge <stigge at antcom.de>
IIO Driver for Maxim MAX517, MAX518 and MAX519 DAC
Signed-off-by: Roland Stigge <stigge at antcom.de>
Acked-by: Jonathan Cameron <jic23 at cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>
---
drivers/staging/iio/Documentation/dac/max517 | 41 ++++
drivers/staging/iio/dac/Kconfig | 10 +
drivers/staging/iio/dac/Makefile | 1 +
drivers/staging/iio/dac/max517.c | 293 ++++++++++++++++++++++++++
drivers/staging/iio/dac/max517.h | 19 ++
5 files changed, 364 insertions(+), 0 deletions(-)
create mode 100644 drivers/staging/iio/Documentation/dac/max517
create mode 100644 drivers/staging/iio/dac/max517.c
create mode 100644 drivers/staging/iio/dac/max517.h
diff --git a/drivers/staging/iio/Documentation/dac/max517 b/drivers/staging/iio/Documentation/dac/max517
new file mode 100644
index 0000000..e60ec2f
--- /dev/null
+++ b/drivers/staging/iio/Documentation/dac/max517
@@ -0,0 +1,41 @@
+Kernel driver max517
+====================
+
+Supported chips:
+ * Maxim MAX517, MAX518, MAX519
+ Prefix: 'max517'
+ Datasheet: Publicly available at the Maxim website
+ http://www.maxim-ic.com/
+
+Author:
+ Roland Stigge <stigge at antcom.de>
+
+Description
+-----------
+
+The Maxim MAX517/518/519 is an 8-bit DAC on the I2C bus. The following table
+shows the different feature sets of the variants MAX517, MAX518 and MAX519:
+
+Feature MAX517 MAX518 MAX519
+--------------------------------------------------------------------------
+One output channel X
+Two output channels X X
+Simultaneous output updates X X
+Supply voltage as reference X
+Separate reference input X
+Reference input for each DAC X
+
+Via the iio sysfs interface, there are three attributes available: out1_raw,
+out2_raw and out12_raw. With out1_raw and out2_raw, the current output values
+(0..255) of the DACs can be written to the device. out12_raw can be used to set
+both output channel values simultaneously.
+
+With MAX517, only out1_raw is available.
+
+Via out1_scale (and where appropriate, out2_scale), the current scaling factor
+in mV can be read.
+
+When the operating system goes to a power down state, the Power Down function
+of the chip is activated, reducing the supply current to 4uA.
+
+On power-up, the device is in 0V-output state.
diff --git a/drivers/staging/iio/dac/Kconfig b/drivers/staging/iio/dac/Kconfig
index 9191bd2..2120904 100644
--- a/drivers/staging/iio/dac/Kconfig
+++ b/drivers/staging/iio/dac/Kconfig
@@ -19,3 +19,13 @@ config AD5446
To compile this driver as a module, choose M here: the
module will be called ad5446.
+
+config MAX517
+ tristate "Maxim MAX517/518/519 DAC driver"
+ depends on I2C && EXPERIMENTAL
+ help
+ If you say yes here you get support for the Maxim chips MAX517,
+ MAX518 and MAX519 (I2C 8-Bit DACs with rail-to-rail outputs).
+
+ This driver can also be built as a module. If so, the module
+ will be called max517.
diff --git a/drivers/staging/iio/dac/Makefile b/drivers/staging/iio/dac/Makefile
index 7cf331b..1197aef 100644
--- a/drivers/staging/iio/dac/Makefile
+++ b/drivers/staging/iio/dac/Makefile
@@ -4,3 +4,4 @@
obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
obj-$(CONFIG_AD5446) += ad5446.o
+obj-$(CONFIG_MAX517) += max517.o
diff --git a/drivers/staging/iio/dac/max517.c b/drivers/staging/iio/dac/max517.c
new file mode 100644
index 0000000..4974e70
--- /dev/null
+++ b/drivers/staging/iio/dac/max517.c
@@ -0,0 +1,293 @@
+/*
+ * max517.c - Support for Maxim MAX517, MAX518 and MAX519
+ *
+ * Copyright (C) 2010, 2011 Roland Stigge <stigge at 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/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+
+#include "../iio.h"
+#include "dac.h"
+
+#include "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,
+};
+
+struct max517_data {
+ struct iio_dev *indio_dev;
+ unsigned short vref_mv[2];
+};
+
+/*
+ * channel: bit 0: channel 1
+ * bit 1: channel 2
+ * (this way, it's possible to set both channels at once)
+ */
+static ssize_t max517_set_value(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count, int channel)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ u8 outbuf[4]; /* 1x or 2x command + value */
+ int outbuf_size = 0;
+ int res;
+ long val;
+
+ res = strict_strtol(buf, 10, &val);
+
+ if (res)
+ return res;
+
+ if (val < 0 || val > 255)
+ return -EINVAL;
+
+ if (channel & 1) {
+ outbuf[outbuf_size++] = COMMAND_CHANNEL0;
+ outbuf[outbuf_size++] = val;
+ }
+ if (channel & 2) {
+ outbuf[outbuf_size++] = COMMAND_CHANNEL1;
+ outbuf[outbuf_size++] = val;
+ }
+
+ /*
+ * At this point, there are always 1 or 2 two-byte commands in
+ * outbuf. With 2 commands, the device can set two outputs
+ * simultaneously, latching the values upon the end of the I2C
+ * transfer.
+ */
+
+ res = i2c_master_send(client, outbuf, outbuf_size);
+ if (res < 0)
+ return res;
+
+ return count;
+}
+
+static ssize_t max517_set_value_1(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return max517_set_value(dev, attr, buf, count, 1);
+}
+static IIO_DEV_ATTR_OUT_RAW(1, max517_set_value_1, 0);
+
+static ssize_t max517_set_value_2(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return max517_set_value(dev, attr, buf, count, 2);
+}
+static IIO_DEV_ATTR_OUT_RAW(2, max517_set_value_2, 1);
+
+static ssize_t max517_set_value_both(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return max517_set_value(dev, attr, buf, count, 3);
+}
+static IIO_DEVICE_ATTR_NAMED(out1and2_raw, out1&2_raw, S_IWUSR, NULL,
+ max517_set_value_both, -1);
+
+static ssize_t max517_show_scale(struct device *dev,
+ struct device_attribute *attr,
+ char *buf, int channel)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct max517_data *data = iio_dev_get_devdata(dev_info);
+ /* Corresponds to Vref / 2^(bits) */
+ unsigned int scale_uv = (data->vref_mv[channel - 1] * 1000) >> 8;
+
+ return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000);
+}
+
+static ssize_t max517_show_scale1(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return max517_show_scale(dev, attr, buf, 1);
+}
+static IIO_DEVICE_ATTR(out1_scale, S_IRUGO, max517_show_scale1, NULL, 0);
+
+static ssize_t max517_show_scale2(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return max517_show_scale(dev, attr, buf, 2);
+}
+static IIO_DEVICE_ATTR(out2_scale, S_IRUGO, max517_show_scale2, NULL, 0);
+
+/* On MAX517 variant, we have two outputs */
+static struct attribute *max517_attributes[] = {
+ &iio_dev_attr_out1_raw.dev_attr.attr,
+ &iio_dev_attr_out1_scale.dev_attr.attr,
+ NULL
+};
+
+static struct attribute_group max517_attribute_group = {
+ .attrs = max517_attributes,
+};
+
+/* On MAX518 and MAX518 variant, we have two outputs */
+static struct attribute *max518_attributes[] = {
+ &iio_dev_attr_out1_raw.dev_attr.attr,
+ &iio_dev_attr_out1_scale.dev_attr.attr,
+ &iio_dev_attr_out2_raw.dev_attr.attr,
+ &iio_dev_attr_out2_scale.dev_attr.attr,
+ &iio_dev_attr_out1and2_raw.dev_attr.attr,
+ NULL
+};
+
+static struct attribute_group max518_attribute_group = {
+ .attrs = max518_attributes,
+};
+
+static int max517_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+ u8 outbuf = COMMAND_PD;
+
+ return i2c_master_send(client, &outbuf, 1);
+}
+
+static int max517_resume(struct i2c_client *client)
+{
+ u8 outbuf = 0;
+
+ return i2c_master_send(client, &outbuf, 1);
+}
+
+static int max517_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct max517_data *data;
+ struct max517_platform_data *platform_data = client->dev.platform_data;
+ int err;
+
+ data = kzalloc(sizeof(struct max517_data), GFP_KERNEL);
+ if (!data) {
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ i2c_set_clientdata(client, data);
+
+ data->indio_dev = iio_allocate_device();
+ if (data->indio_dev == NULL) {
+ err = -ENOMEM;
+ goto exit_free_data;
+ }
+
+ /* establish that the iio_dev is a child of the i2c device */
+ data->indio_dev->dev.parent = &client->dev;
+
+ /* reduced attribute set for MAX517 */
+ if (id->driver_data == ID_MAX517)
+ data->indio_dev->attrs = &max517_attribute_group;
+ else
+ data->indio_dev->attrs = &max518_attribute_group;
+ data->indio_dev->dev_data = (void *)(data);
+ data->indio_dev->driver_module = THIS_MODULE;
+ data->indio_dev->modes = INDIO_DIRECT_MODE;
+
+ /*
+ * Reference voltage on MAX518 and default is 5V, else take vref_mv
+ * from platform_data
+ */
+ if (id->driver_data == ID_MAX518 || !platform_data) {
+ data->vref_mv[0] = data->vref_mv[1] = 5000; /* mV */
+ } else {
+ data->vref_mv[0] = platform_data->vref_mv[0];
+ data->vref_mv[1] = platform_data->vref_mv[1];
+ }
+
+ err = iio_device_register(data->indio_dev);
+ if (err)
+ goto exit_free_device;
+
+ dev_info(&client->dev, "DAC registered\n");
+
+ return 0;
+
+exit_free_device:
+ iio_free_device(data->indio_dev);
+exit_free_data:
+ kfree(data);
+exit:
+ return err;
+}
+
+static int max517_remove(struct i2c_client *client)
+{
+ struct max517_data *data = i2c_get_clientdata(client);
+
+ iio_free_device(data->indio_dev);
+ kfree(data);
+
+ return 0;
+}
+
+static const struct i2c_device_id max517_id[] = {
+ { "max517", ID_MAX517 },
+ { "max518", ID_MAX518 },
+ { "max519", ID_MAX519 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max517_id);
+
+static struct i2c_driver max517_driver = {
+ .driver = {
+ .name = MAX517_DRV_NAME,
+ },
+ .probe = max517_probe,
+ .remove = max517_remove,
+ .suspend = max517_suspend,
+ .resume = max517_resume,
+ .id_table = max517_id,
+};
+
+static int __init max517_init(void)
+{
+ return i2c_add_driver(&max517_driver);
+}
+
+static void __exit max517_exit(void)
+{
+ i2c_del_driver(&max517_driver);
+}
+
+MODULE_AUTHOR("Roland Stigge <stigge at antcom.de>");
+MODULE_DESCRIPTION("MAX517/MAX518/MAX519 8-bit DAC");
+MODULE_LICENSE("GPL");
+
+module_init(max517_init);
+module_exit(max517_exit);
diff --git a/drivers/staging/iio/dac/max517.h b/drivers/staging/iio/dac/max517.h
new file mode 100644
index 0000000..8106cf2
--- /dev/null
+++ b/drivers/staging/iio/dac/max517.h
@@ -0,0 +1,19 @@
+/*
+ * MAX517 DAC driver
+ *
+ * Copyright 2011 Roland Stigge <stigge at antcom.de>
+ *
+ * Licensed under the GPL-2 or later.
+ */
+#ifndef IIO_DAC_MAX517_H_
+#define IIO_DAC_MAX517_H_
+
+/*
+ * TODO: struct max517_platform_data needs to go into include/linux/iio
+ */
+
+struct max517_platform_data {
+ u16 vref_mv[2];
+};
+
+#endif /* IIO_DAC_MAX517_H_ */
--
1.7.4.1
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