Driver for Microchip digital potentiometers

From: Peter Rosin <[email protected]>

Signed-off-by Peter Rosin <[email protected]>

---
 Documentation/ABI/testing/sysfs-bus-iio |    2 ++
 1 file changed, 2 insertions(+)

Documentation/ABI/testing/sysfs-bus-iio +2 -0

index 9398484196c4..2eea468f704d 100644
@@ -1475,6 +1475,8 @@ Description:
 
 What:		/sys/bus/iio/devices/iio:deviceX/in_resistance_raw
 What:		/sys/bus/iio/devices/iio:deviceX/in_resistanceX_raw
+What:		/sys/bus/iio/devices/iio:deviceX/out_resistance_raw
+What:		/sys/bus/iio/devices/iio:deviceX/out_resistanceX_raw
 KernelVersion:	4.3
 Contact:	[email protected]
 Description:

From: Peter Rosin <[email protected]>

Add support for Microchip digital potentiometers and rheostats

	MCP4531, MCP4532, MCP4551, MCP4552
	MCP4631, MCP4632, MCP4651, MCP4652

DEVICE   Wipers  Steps  Resistor Opts (kOhm)  i2c address
MCP4531  1       129    5, 10, 50, 100        010111x
MCP4532  1       129    5, 10, 50, 100        01011xx
MCP4551  1       257    5, 10, 50, 100        010111x
MCP4552  1       257    5, 10, 50, 100        01011xx
MCP4631  2       129    5, 10, 50, 100        0101xxx
MCP4632  2       129    5, 10, 50, 100        01011xx
MCP4651  2       257    5, 10, 50, 100        0101xxx
MCP4652  2       257    5, 10, 50, 100        01011xx

Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf

Signed-off-by Peter Rosin <[email protected]>

---
 MAINTAINERS                         |    6 +
 drivers/iio/Kconfig                 |    1 +
 drivers/iio/Makefile                |    1 +
 drivers/iio/potentiometer/Kconfig   |   20 +++
 drivers/iio/potentiometer/Makefile  |    6 +
 drivers/iio/potentiometer/mcp4531.c |  231 +++++++++++++++++++++++++++++++++++
 6 files changed, 265 insertions(+)
 create mode 100644 drivers/iio/potentiometer/Kconfig
 create mode 100644 drivers/iio/potentiometer/Makefile
 create mode 100644 drivers/iio/potentiometer/mcp4531.c

MAINTAINERS +6 -0

index b60e2b2369d2..27862156c7a7 100644
@@ -6600,6 +6600,12 @@ W:	http://linuxtv.org
 S:	Maintained
 F:	drivers/media/radio/radio-maxiradio*
 
+MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVER
+M:	Peter Rosin <[email protected]>
+L:	[email protected]
+S:	Maintained
+F:	drivers/iio/potentiometer/mcp4531.c
+
 MEDIA DRIVERS FOR RENESAS - VSP1
 M:	Laurent Pinchart <[email protected]>
 L:	[email protected]

drivers/iio/Kconfig +1 -0

index 4011effe4c05..7cc87f322655 100644
@@ -73,6 +73,7 @@ source "drivers/iio/orientation/Kconfig"
 if IIO_TRIGGER
    source "drivers/iio/trigger/Kconfig"
 endif #IIO_TRIGGER
+source "drivers/iio/potentiometer/Kconfig"
 source "drivers/iio/pressure/Kconfig"
 source "drivers/iio/proximity/Kconfig"
 source "drivers/iio/temperature/Kconfig"

drivers/iio/Makefile +1 -0

index 698afc2d17ce..121c814e366b 100644
@@ -23,6 +23,7 @@ obj-y += imu/
 obj-y += light/
 obj-y += magnetometer/
 obj-y += orientation/
+obj-y += potentiometer/
 obj-y += pressure/
 obj-y += proximity/
 obj-y += temperature/

drivers/iio/potentiometer/Kconfig new file +20 -0

new file mode 100644
index 000000000000..fd75db73e582
@@ -0,0 +1,20 @@
+#
+# Potentiometer drivers
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Digital potentiometers"
+
+config MCP4531
+	tristate "Microchip MCP45xx/MCP46xx Digital Potentiometer driver"
+	depends on I2C
+	help
+	  Say yes here to build support for the Microchip
+	  MCP4531, MCP4532, MCP4551, MCP4552,
+	  MCP4631, MCP4632, MCP4651, MCP4652
+	  digital potentiomenter chips.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mcp4531.
+
+endmenu

drivers/iio/potentiometer/Makefile new file +6 -0

new file mode 100644
index 000000000000..8afe49227012
@@ -0,0 +1,6 @@
+#
+# Makefile for industrial I/O potentiometer drivers
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_MCP4531) += mcp4531.o

drivers/iio/potentiometer/mcp4531.c new file +231 -0

new file mode 100644
index 000000000000..a3f66874ee2e
@@ -0,0 +1,231 @@
+/*
+ * Industrial I/O driver for Microchip digital potentiometers
+ * Copyright (c) 2015  Axentia Technologies AB
+ * Author: Peter Rosin <[email protected]>
+ *
+ * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf
+ *
+ * DEVID	#Wipers	#Positions	Resistor Opts (kOhm)	i2c address
+ * mcp4531	1	129		5, 10, 50, 100          010111x
+ * mcp4532	1	129		5, 10, 50, 100          01011xx
+ * mcp4551	1	257		5, 10, 50, 100          010111x
+ * mcp4552	1	257		5, 10, 50, 100          01011xx
+ * mcp4631	2	129		5, 10, 50, 100          0101xxx
+ * mcp4632	2	129		5, 10, 50, 100          01011xx
+ * mcp4651	2	257		5, 10, 50, 100          0101xxx
+ * mcp4652	2	257		5, 10, 50, 100          01011xx
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+
+#include <linux/iio/iio.h>
+
+struct mcp4531_cfg {
+	int wipers;
+	int max_pos;
+	int kohms;
+};
+
+enum mcp4531_type {
+	MCP453x_502,
+	MCP453x_103,
+	MCP453x_503,
+	MCP453x_104,
+	MCP455x_502,
+	MCP455x_103,
+	MCP455x_503,
+	MCP455x_104,
+	MCP463x_502,
+	MCP463x_103,
+	MCP463x_503,
+	MCP463x_104,
+	MCP465x_502,
+	MCP465x_103,
+	MCP465x_503,
+	MCP465x_104,
+};
+
+static const struct mcp4531_cfg mcp4531_cfg[] = {
+	[MCP453x_502] = { .wipers = 1, .max_pos = 128, .kohms =   5, },
+	[MCP453x_103] = { .wipers = 1, .max_pos = 128, .kohms =  10, },
+	[MCP453x_503] = { .wipers = 1, .max_pos = 128, .kohms =  50, },
+	[MCP453x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, },
+	[MCP455x_502] = { .wipers = 1, .max_pos = 256, .kohms =   5, },
+	[MCP455x_103] = { .wipers = 1, .max_pos = 256, .kohms =  10, },
+	[MCP455x_503] = { .wipers = 1, .max_pos = 256, .kohms =  50, },
+	[MCP455x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, },
+	[MCP463x_502] = { .wipers = 2, .max_pos = 128, .kohms =   5, },
+	[MCP463x_103] = { .wipers = 2, .max_pos = 128, .kohms =  10, },
+	[MCP463x_503] = { .wipers = 2, .max_pos = 128, .kohms =  50, },
+	[MCP463x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, },
+	[MCP465x_502] = { .wipers = 2, .max_pos = 256, .kohms =   5, },
+	[MCP465x_103] = { .wipers = 2, .max_pos = 256, .kohms =  10, },
+	[MCP465x_503] = { .wipers = 2, .max_pos = 256, .kohms =  50, },
+	[MCP465x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, },
+};
+
+#define MCP4531_WRITE (0 << 2)
+#define MCP4531_INCR  (1 << 2)
+#define MCP4531_DECR  (2 << 2)
+#define MCP4531_READ  (3 << 2)
+
+#define MCP4531_WIPER_SHIFT (4)
+
+struct mcp4531_data {
+	struct i2c_client *client;
+	unsigned long devid;
+};
+
+#define MCP4531_CHANNEL(ch) {					\
+	.type = IIO_RESISTANCE,					\
+	.indexed = 1,						\
+	.output = 1,						\
+	.channel = (ch),					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+}
+
+static const struct iio_chan_spec mcp4531_channels[] = {
+	MCP4531_CHANNEL(0),
+	MCP4531_CHANNEL(1),
+};
+
+static int mcp4531_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct mcp4531_data *data = iio_priv(indio_dev);
+	int address = chan->channel << MCP4531_WIPER_SHIFT;
+	s32 ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = i2c_smbus_read_word_swapped(data->client,
+						  MCP4531_READ | address);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 1000 * mcp4531_cfg[data->devid].kohms;
+		*val2 = mcp4531_cfg[data->devid].max_pos;
+		return IIO_VAL_FRACTIONAL;
+	}
+
+	return -EINVAL;
+}
+
+static int mcp4531_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	struct mcp4531_data *data = iio_priv(indio_dev);
+	int address = chan->channel << MCP4531_WIPER_SHIFT;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (val > mcp4531_cfg[data->devid].max_pos || val < 0)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return i2c_smbus_write_byte_data(data->client,
+					 MCP4531_WRITE | address | (val >> 8),
+					 val & 0xff);
+}
+
+static const struct iio_info mcp4531_info = {
+	.read_raw = mcp4531_read_raw,
+	.write_raw = mcp4531_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int mcp4531_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	unsigned long devid = id->driver_data;
+	struct mcp4531_data *data;
+	struct iio_dev *indio_dev;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_WORD_DATA)) {
+		dev_err(dev, "SMBUS Word Data not supported\n");
+		return -EIO;
+	}
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	data->devid = devid;
+
+	indio_dev->dev.parent = dev;
+	indio_dev->info = &mcp4531_info;
+	indio_dev->channels = mcp4531_channels;
+	indio_dev->num_channels = mcp4531_cfg[devid].wipers;
+	indio_dev->name = client->name;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct i2c_device_id mcp4531_id[] = {
+	{ "mcp4531-502", MCP453x_502 },
+	{ "mcp4531-103", MCP453x_103 },
+	{ "mcp4531-503", MCP453x_503 },
+	{ "mcp4531-104", MCP453x_104 },
+	{ "mcp4532-502", MCP453x_502 },
+	{ "mcp4532-103", MCP453x_103 },
+	{ "mcp4532-503", MCP453x_503 },
+	{ "mcp4532-104", MCP453x_104 },
+	{ "mcp4551-502", MCP455x_502 },
+	{ "mcp4551-103", MCP455x_103 },
+	{ "mcp4551-503", MCP455x_503 },
+	{ "mcp4551-104", MCP455x_104 },
+	{ "mcp4552-502", MCP455x_502 },
+	{ "mcp4552-103", MCP455x_103 },
+	{ "mcp4552-503", MCP455x_503 },
+	{ "mcp4552-104", MCP455x_104 },
+	{ "mcp4631-502", MCP463x_502 },
+	{ "mcp4631-103", MCP463x_103 },
+	{ "mcp4631-503", MCP463x_503 },
+	{ "mcp4631-104", MCP463x_104 },
+	{ "mcp4632-502", MCP463x_502 },
+	{ "mcp4632-103", MCP463x_103 },
+	{ "mcp4632-503", MCP463x_503 },
+	{ "mcp4632-104", MCP463x_104 },
+	{ "mcp4651-502", MCP465x_502 },
+	{ "mcp4651-103", MCP465x_103 },
+	{ "mcp4651-503", MCP465x_503 },
+	{ "mcp4651-104", MCP465x_104 },
+	{ "mcp4652-502", MCP465x_502 },
+	{ "mcp4652-103", MCP465x_103 },
+	{ "mcp4652-503", MCP465x_503 },
+	{ "mcp4652-104", MCP465x_104 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, mcp4531_id);
+
+static struct i2c_driver mcp4531_driver = {
+	.driver = {
+		.name	= "mcp4531",
+	},
+	.probe		= mcp4531_probe,
+	.id_table	= mcp4531_id,
+};
+
+module_i2c_driver(mcp4531_driver);
+
+MODULE_AUTHOR("Peter Rosin <[email protected]>");
+MODULE_DESCRIPTION("MCP4531 digital potentiometer");
+MODULE_LICENSE("GPL");

Quoted 16 lines · Peter Rosin

From: Peter Rosin <[email protected]>

Add support for Microchip digital potentiometers and rheostats

	MCP4531, MCP4532, MCP4551, MCP4552
	MCP4631, MCP4632, MCP4651, MCP4652

DEVICE   Wipers  Steps  Resistor Opts (kOhm)  i2c address
MCP4531  1       129    5, 10, 50, 100        010111x
MCP4532  1       129    5, 10, 50, 100        01011xx
MCP4551  1       257    5, 10, 50, 100        010111x
MCP4552  1       257    5, 10, 50, 100        01011xx
MCP4631  2       129    5, 10, 50, 100        0101xxx
MCP4632  2       129    5, 10, 50, 100        01011xx
MCP4651  2       257    5, 10, 50, 100        0101xxx
MCP4652  2       257    5, 10, 50, 100        01011xx

Quoted 1 line

Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf

Applied to the togreg branch of iio.git - initially pushed out as testing for the autobuilders to play with it.

If anyone wants to add reviewed-by / acked-by then as I'll be rebasing sometime in next few days anyway there is still time!

Quoted 17 lines · Jonathan Cameron

Quoted 16 lines · Peter Rosin

From: Peter Rosin <[email protected]>

Add support for Microchip digital potentiometers and rheostats

     MCP4531, MCP4532, MCP4551, MCP4552
     MCP4631, MCP4632, MCP4651, MCP4652

DEVICE   Wipers  Steps  Resistor Opts (kOhm)  i2c address
MCP4531  1       129    5, 10, 50, 100        010111x
MCP4532  1       129    5, 10, 50, 100        01011xx
MCP4551  1       257    5, 10, 50, 100        010111x
MCP4552  1       257    5, 10, 50, 100        01011xx
MCP4631  2       129    5, 10, 50, 100        0101xxx
MCP4632  2       129    5, 10, 50, 100        01011xx
MCP4651  2       257    5, 10, 50, 100        0101xxx
MCP4652  2       257    5, 10, 50, 100        01011xx

Quoted 6 lines

Quoted 1 line

Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf

Applied to the togreg branch of iio.git - initially pushed out as testing for the autobuilders to play with it.

If anyone wants to add reviewed-by / acked-by then as I'll be rebasing sometime in next few days anyway there is still time!

Great, thanks,

but I don't see this where I expected it[1]. So, the question is if I'm too impatient, if am I looking in the wrong place or if you perhaps forgot to actually push it out? Or if something went totally wrong and the patches got lost...

Quoted 18 lines · Peter Rosin

Quoted 17 lines · Jonathan Cameron

Quoted 16 lines · Peter Rosin

From: Peter Rosin <[email protected]>

Add support for Microchip digital potentiometers and rheostats

     MCP4531, MCP4532, MCP4551, MCP4552
     MCP4631, MCP4632, MCP4651, MCP4652

DEVICE   Wipers  Steps  Resistor Opts (kOhm)  i2c address
MCP4531  1       129    5, 10, 50, 100        010111x
MCP4532  1       129    5, 10, 50, 100        01011xx
MCP4551  1       257    5, 10, 50, 100        010111x
MCP4552  1       257    5, 10, 50, 100        01011xx
MCP4631  2       129    5, 10, 50, 100        0101xxx
MCP4632  2       129    5, 10, 50, 100        01011xx
MCP4651  2       257    5, 10, 50, 100        0101xxx
MCP4652  2       257    5, 10, 50, 100        01011xx

Quoted 1 line

Quoted 1 line

Quoted 1 line

Datasheet:

http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf

Quoted 9 lines

Quoted 5 lines

Applied to the togreg branch of iio.git - initially pushed out as testing for the autobuilders to play with it.

If anyone wants to add reviewed-by / acked-by then as I'll be rebasing sometime in next few days anyway there is still time!

Great, thanks,

but I don't see this where I expected it[1]. So, the question is if

I'm

Quoted 1 line

too impatient, if am I looking in the wrong place or if you perhaps

forgot

Quoted 1 line

to actually push it out? Or if something went totally wrong and the

patches

Quoted 1 line

got lost...

Make sure you look for the testing branch. Also, do not worry about this.

Sometimes, Jonathan pushes the patches locally to his setup and later syncs with the remote repo.

On 28 September 2015 09:11:09 BST, Daniel Baluta <[email protected]> wrote:

    On Mon, Sep 28, 2015 at 10:59 AM, Peter Rosin <[email protected]> wrote:

        On 2015-09-27 17:50, Jonathan Cameron wrote:

            On 23/09/15 15:26, Peter Rosin wrote:

                From: Peter Rosin <[email protected]>

                Add support for Microchip digital potentiometers and rheostats
                MCP4531, MCP4532, MCP4551, MCP4552
                MCP4631, MCP4632, MCP4651, MCP4652

                DEVICE Wipers Steps Resistor Opts (kOhm) i2c address
                MCP4531 1 129 5, 10, 50, 100 010111x
                MCP4532 1 129 5, 10, 50, 100 01011xx
                MCP4551 1 257 5, 10 , 50, 100 010111x
                MCP4552 1 257 5, 10, 50, 100 01011xx
                MCP4631 2 129 5, 10, 50, 100 0101xxx
                MCP4632 2 129 5, 10, 50, 100 01011xx
                MCP4651 2 257 5, 10, 50, 100 0101xxx
                MCP4652 2 257 5, 10, 50, 100 01011xx

                Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf

            Applied to the togreg branch of iio.git - initially pushed out as
            testing for the autobuilders to play with it.

            If anyone wants to add reviewed-by / acked-by then as I'll be
            rebasing sometime in next few days anyway there is still time!


        Great, thanks,

        but I don't see this where I expected it[1]. So, the question is if I'm
        too impatient, if am I looking in the wrong place or if you perhaps forgot
        to actually push it out? Or if something went totally wrong and the patches
        got lost...


    Make sure you look for the testing branch. Also, do not worry about this.

    Sometimes, Jonathan  pushes the patches locally to his setup and later
    syncs with the remote repo.

What Daniel is politely saying is sometimes I forget to push them out! Oops. Machine is at home and powered down so should push testing branch this evening if I remember.

Signature · 2 lines

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