// SPDX-License-Identifier: GPL-2.0-only /* * 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 #include #include #include #include #include #include #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 avail[3]; int kohms; const struct iio_chan_spec *channels; u8 num_channels; int (*read)(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val); }; struct ds1803_data { struct i2c_client *client; const struct ds1803_cfg *cfg; }; #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_WIPER_0), DS1803_CHANNEL(1, DS1803_WIPER_1), }; static const struct iio_chan_spec ds3502_channels[] = { DS1803_CHANNEL(0, DS3502_WR_IVR), }; static int ds1803_read(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val) { struct ds1803_data *data = iio_priv(indio_dev); int ret; u8 result[ARRAY_SIZE(ds1803_channels)]; ret = i2c_master_recv(data->client, result, indio_dev->num_channels); if (ret < 0) return ret; *val = result[chan->channel]; return ret; } static int ds3502_read(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val) { struct ds1803_data *data = iio_priv(indio_dev); int ret; ret = i2c_smbus_read_byte_data(data->client, chan->address); if (ret < 0) return ret; *val = ret; return ret; } 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), .read = ds1803_read, }, [DS1803_050] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 50, .channels = ds1803_channels, .num_channels = ARRAY_SIZE(ds1803_channels), .read = ds1803_read, }, [DS1803_100] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 100, .channels = ds1803_channels, .num_channels = ARRAY_SIZE(ds1803_channels), .read = ds1803_read, }, [DS3502] = { .wipers = 1, .avail = { 0, 1, 127 }, .kohms = 10, .channels = ds3502_channels, .num_channels = ARRAY_SIZE(ds3502_channels), .read = ds3502_read, }, }; static int ds1803_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct ds1803_data *data = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_RAW: ret = data->cfg->read(indio_dev, chan, val); if (ret < 0) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 1000 * data->cfg->kohms; *val2 = data->cfg->avail[2]; /* Max wiper position */ return IIO_VAL_FRACTIONAL; } return -EINVAL; } static int ds1803_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct ds1803_data *data = iio_priv(indio_dev); u8 addr = chan->address; int max_pos = data->cfg->avail[2]; if (val2 != 0) return -EINVAL; switch (mask) { case IIO_CHAN_INFO_RAW: if (val > max_pos || val < 0) return -EINVAL; break; default: return -EINVAL; } 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, const int **vals, int *type, int *length, long mask) { struct ds1803_data *data = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_RAW: *vals = data->cfg->avail; *length = ARRAY_SIZE(data->cfg->avail); *type = IIO_VAL_INT; return IIO_AVAIL_RANGE; } return -EINVAL; } static const struct iio_info ds1803_info = { .read_raw = ds1803_read_raw, .write_raw = ds1803_write_raw, .read_avail = ds1803_read_avail, }; static int ds1803_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct ds1803_data *data; struct iio_dev *indio_dev; indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; i2c_set_clientdata(client, indio_dev); data = iio_priv(indio_dev); data->client = client; data->cfg = i2c_get_match_data(client); indio_dev->info = &ds1803_info; 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,ds3502", .data = &ds1803_cfg[DS3502] }, {} }; MODULE_DEVICE_TABLE(of, ds1803_dt_ids); static const struct i2c_device_id ds1803_id[] = { { "ds1803-010", (kernel_ulong_t)&ds1803_cfg[DS1803_010] }, { "ds1803-050", (kernel_ulong_t)&ds1803_cfg[DS1803_050] }, { "ds1803-100", (kernel_ulong_t)&ds1803_cfg[DS1803_100] }, { "ds3502", (kernel_ulong_t)&ds1803_cfg[DS3502] }, {} }; MODULE_DEVICE_TABLE(i2c, ds1803_id); static struct i2c_driver ds1803_driver = { .driver = { .name = "ds1803", .of_match_table = ds1803_dt_ids, }, .probe = ds1803_probe, .id_table = ds1803_id, }; module_i2c_driver(ds1803_driver); MODULE_AUTHOR("Slawomir Stepien "); MODULE_AUTHOR("Jagath Jog J "); MODULE_DESCRIPTION("DS1803 digital potentiometer"); MODULE_LICENSE("GPL v2");