[PATCH v2 3/4] iio: potentiometer: Add support for Maxim DS3502
From: Jagath Jog J
Date: Sun Feb 13 2022 - 22:36:39 EST
The DS3502 is a 7-bit, nonvolatile digital potentiometer featuring
an output voltage range of up to 15.5V.
DS3502 support is implemented into existing ds1803 driver
Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3502.pdf
Signed-off-by: Jagath Jog J <jagathjog1996@xxxxxxxxx>
---
drivers/iio/potentiometer/Kconfig | 6 +-
drivers/iio/potentiometer/ds1803.c | 101 ++++++++++++++++++++---------
2 files changed, 75 insertions(+), 32 deletions(-)
diff --git a/drivers/iio/potentiometer/Kconfig b/drivers/iio/potentiometer/Kconfig
index 832df8da2bc6..cd9aaceb15fe 100644
--- a/drivers/iio/potentiometer/Kconfig
+++ b/drivers/iio/potentiometer/Kconfig
@@ -27,11 +27,11 @@ config AD5272
module will be called ad5272.
config DS1803
- tristate "Maxim Integrated DS1803 Digital Potentiometer driver"
+ tristate "Maxim Integrated DS1803 and similar Digital Potentiometer driver"
depends on I2C
help
- Say yes here to build support for the Maxim Integrated DS1803
- digital potentiometer chip.
+ Say yes here to build support for the Maxim Integrated DS1803 and
+ similar digital potentiometer chip.
To compile this driver as a module, choose M here: the
module will be called ds1803.
diff --git a/drivers/iio/potentiometer/ds1803.c b/drivers/iio/potentiometer/ds1803.c
index bccb9ccac931..0990536e7f36 100644
--- a/drivers/iio/potentiometer/ds1803.c
+++ b/drivers/iio/potentiometer/ds1803.c
@@ -1,12 +1,15 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Maxim Integrated DS1803 digital potentiometer driver
+ * Maxim Integrated DS1803 and similar digital potentiometer driver
* Copyright (c) 2016 Slawomir Stepien
+ * Copyright (c) 2022 Jagath Jog J
*
* Datasheet: https://datasheets.maximintegrated.com/en/ds/DS1803.pdf
+ * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3502.pdf
*
* DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address
* ds1803 2 256 10, 50, 100 0101xxx
+ * ds3502 1 128 10 01010xx
*/
#include <linux/err.h>
@@ -16,44 +19,64 @@
#include <linux/module.h>
#include <linux/mod_devicetable.h>
-#define DS1803_MAX_POS 255
-#define DS1803_WRITE(chan) (0xa8 | ((chan) + 1))
+#define DS1803_WIPER_0 0xA9
+#define DS1803_WIPER_1 0xAA
+#define DS3502_WR_IVR 0x00
enum ds1803_type {
DS1803_010,
DS1803_050,
DS1803_100,
+ DS3502,
};
struct ds1803_cfg {
+ int wipers;
int kohms;
int avail[3];
-};
-
-static const struct ds1803_cfg ds1803_cfg[] = {
- [DS1803_010] = { .avail = { 0, 1, 255 }, .kohms = 10, },
- [DS1803_050] = { .avail = { 0, 1, 255 }, .kohms = 50, },
- [DS1803_100] = { .avail = { 0, 1, 255 }, .kohms = 100, },
+ const struct iio_chan_spec *channels;
+ u8 num_channels;
};
struct ds1803_data {
struct i2c_client *client;
const struct ds1803_cfg *cfg;
+ enum ds1803_type chip_type;
};
-#define DS1803_CHANNEL(ch) { \
+#define DS1803_CHANNEL(ch, addr) { \
.type = IIO_RESISTANCE, \
.indexed = 1, \
.output = 1, \
.channel = (ch), \
+ .address = (addr), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW), \
}
static const struct iio_chan_spec ds1803_channels[] = {
- DS1803_CHANNEL(0),
- DS1803_CHANNEL(1),
+ DS1803_CHANNEL(0, DS1803_WIPER_0),
+ DS1803_CHANNEL(1, DS1803_WIPER_1),
+};
+
+static const struct iio_chan_spec ds3502_channels[] = {
+ DS1803_CHANNEL(0, DS3502_WR_IVR),
+};
+
+static const struct ds1803_cfg ds1803_cfg[] = {
+ [DS1803_010] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 10,
+ .channels = ds1803_channels,
+ .num_channels = ARRAY_SIZE(ds1803_channels) },
+ [DS1803_050] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 50,
+ .channels = ds1803_channels,
+ .num_channels = ARRAY_SIZE(ds1803_channels) },
+ [DS1803_100] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 100,
+ .channels = ds1803_channels,
+ .num_channels = ARRAY_SIZE(ds1803_channels) },
+ [DS3502] = { .wipers = 1, .avail = { 0, 1, 127 }, .kohms = 10,
+ .channels = ds3502_channels,
+ .num_channels = ARRAY_SIZE(ds3502_channels) },
};
static int ds1803_read_raw(struct iio_dev *indio_dev,
@@ -67,17 +90,30 @@ static int ds1803_read_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_RAW:
- ret = i2c_master_recv(data->client, result,
- indio_dev->num_channels);
- if (ret < 0)
- return ret;
-
- *val = result[pot];
- return IIO_VAL_INT;
+ switch (data->chip_type) {
+ case DS1803_010:
+ case DS1803_050:
+ case DS1803_100:
+ ret = i2c_master_recv(data->client, result,
+ indio_dev->num_channels);
+ if (ret < 0)
+ return ret;
+ *val = result[pot];
+ return IIO_VAL_INT;
+ case DS3502:
+ ret = i2c_smbus_read_byte_data(data->client,
+ chan->address);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
case IIO_CHAN_INFO_SCALE:
*val = 1000 * data->cfg->kohms;
- *val2 = DS1803_MAX_POS;
+ *val2 = data->cfg->avail[2]; /* Max wiper position */
return IIO_VAL_FRACTIONAL;
}
@@ -89,21 +125,22 @@ static int ds1803_write_raw(struct iio_dev *indio_dev,
int val, int val2, long mask)
{
struct ds1803_data *data = iio_priv(indio_dev);
- int pot = chan->channel;
+ int max_pos = data->cfg->avail[2];
+ u8 addr = chan->address;
if (val2 != 0)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
- if (val > DS1803_MAX_POS || val < 0)
+ if (val > max_pos || val < 0)
return -EINVAL;
break;
default:
return -EINVAL;
}
- return i2c_smbus_write_byte_data(data->client, DS1803_WRITE(pot), val);
+ return i2c_smbus_write_byte_data(data->client, addr, val);
}
static int ds1803_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
@@ -142,20 +179,24 @@ static int ds1803_probe(struct i2c_client *client,
data = iio_priv(indio_dev);
data->client = client;
- data->cfg = &ds1803_cfg[id->driver_data];
+ data->chip_type = (uintptr_t)device_get_match_data(dev);
+ if (data->chip_type < DS1803_010 || data->chip_type > DS3502)
+ data->chip_type = id->driver_data;
+ data->cfg = &ds1803_cfg[data->chip_type];
indio_dev->info = &ds1803_info;
- indio_dev->channels = ds1803_channels;
- indio_dev->num_channels = ARRAY_SIZE(ds1803_channels);
+ indio_dev->channels = data->cfg->channels;
+ indio_dev->num_channels = data->cfg->num_channels;
indio_dev->name = client->name;
return devm_iio_device_register(dev, indio_dev);
}
static const struct of_device_id ds1803_dt_ids[] = {
- { .compatible = "maxim,ds1803-010", .data = &ds1803_cfg[DS1803_010] },
- { .compatible = "maxim,ds1803-050", .data = &ds1803_cfg[DS1803_050] },
- { .compatible = "maxim,ds1803-100", .data = &ds1803_cfg[DS1803_100] },
+ { .compatible = "maxim,ds1803-010", .data = (void *)DS1803_010 },
+ { .compatible = "maxim,ds1803-050", .data = (void *)DS1803_050 },
+ { .compatible = "maxim,ds1803-100", .data = (void *)DS1803_100 },
+ { .compatible = "maxim,ds3502", .data = (void *)DS3502 },
{}
};
MODULE_DEVICE_TABLE(of, ds1803_dt_ids);
@@ -164,6 +205,7 @@ static const struct i2c_device_id ds1803_id[] = {
{ "ds1803-010", DS1803_010 },
{ "ds1803-050", DS1803_050 },
{ "ds1803-100", DS1803_100 },
+ { "ds3502", DS3502 },
{}
};
MODULE_DEVICE_TABLE(i2c, ds1803_id);
@@ -180,5 +222,6 @@ static struct i2c_driver ds1803_driver = {
module_i2c_driver(ds1803_driver);
MODULE_AUTHOR("Slawomir Stepien <sst@xxxxxxxxx>");
+MODULE_AUTHOR("Jagath Jog J <jagathjog1996@xxxxxxxxx>");
MODULE_DESCRIPTION("DS1803 digital potentiometer");
MODULE_LICENSE("GPL v2");
--
2.17.1