179e8a32dSPhil Reid // SPDX-License-Identifier: GPL-2.0+ 279e8a32dSPhil Reid /* 379e8a32dSPhil Reid * Analog Devices AD5272 digital potentiometer driver 479e8a32dSPhil Reid * Copyright (C) 2018 Phil Reid <preid@electromag.com.au> 579e8a32dSPhil Reid * 679e8a32dSPhil Reid * Datasheet: http://www.analog.com/media/en/technical-documentation/data-sheets/AD5272_5274.pdf 779e8a32dSPhil Reid * 879e8a32dSPhil Reid * DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address 979e8a32dSPhil Reid * ad5272 1 1024 20, 50, 100 01011xx 1079e8a32dSPhil Reid * ad5274 1 256 20, 100 01011xx 1179e8a32dSPhil Reid */ 1279e8a32dSPhil Reid 1379e8a32dSPhil Reid #include <linux/delay.h> 1479e8a32dSPhil Reid #include <linux/gpio/consumer.h> 1579e8a32dSPhil Reid #include <linux/i2c.h> 1679e8a32dSPhil Reid #include <linux/iio/iio.h> 1779e8a32dSPhil Reid #include <linux/module.h> 1879e8a32dSPhil Reid 1979e8a32dSPhil Reid #define AD5272_RDAC_WR 1 2079e8a32dSPhil Reid #define AD5272_RDAC_RD 2 2179e8a32dSPhil Reid #define AD5272_RESET 4 2279e8a32dSPhil Reid #define AD5272_CTL 7 2379e8a32dSPhil Reid 2479e8a32dSPhil Reid #define AD5272_RDAC_WR_EN BIT(1) 2579e8a32dSPhil Reid 2679e8a32dSPhil Reid struct ad5272_cfg { 2779e8a32dSPhil Reid int max_pos; 2879e8a32dSPhil Reid int kohms; 2979e8a32dSPhil Reid int shift; 3079e8a32dSPhil Reid }; 3179e8a32dSPhil Reid 3279e8a32dSPhil Reid enum ad5272_type { 3379e8a32dSPhil Reid AD5272_020, 3479e8a32dSPhil Reid AD5272_050, 3579e8a32dSPhil Reid AD5272_100, 3679e8a32dSPhil Reid AD5274_020, 3779e8a32dSPhil Reid AD5274_100, 3879e8a32dSPhil Reid }; 3979e8a32dSPhil Reid 4079e8a32dSPhil Reid static const struct ad5272_cfg ad5272_cfg[] = { 4179e8a32dSPhil Reid [AD5272_020] = { .max_pos = 1024, .kohms = 20 }, 4279e8a32dSPhil Reid [AD5272_050] = { .max_pos = 1024, .kohms = 50 }, 4379e8a32dSPhil Reid [AD5272_100] = { .max_pos = 1024, .kohms = 100 }, 4479e8a32dSPhil Reid [AD5274_020] = { .max_pos = 256, .kohms = 20, .shift = 2 }, 4579e8a32dSPhil Reid [AD5274_100] = { .max_pos = 256, .kohms = 100, .shift = 2 }, 4679e8a32dSPhil Reid }; 4779e8a32dSPhil Reid 4879e8a32dSPhil Reid struct ad5272_data { 4979e8a32dSPhil Reid struct i2c_client *client; 5079e8a32dSPhil Reid struct mutex lock; 5179e8a32dSPhil Reid const struct ad5272_cfg *cfg; 5279e8a32dSPhil Reid u8 buf[2] ____cacheline_aligned; 5379e8a32dSPhil Reid }; 5479e8a32dSPhil Reid 5579e8a32dSPhil Reid static const struct iio_chan_spec ad5272_channel = { 5679e8a32dSPhil Reid .type = IIO_RESISTANCE, 5779e8a32dSPhil Reid .output = 1, 5879e8a32dSPhil Reid .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 5979e8a32dSPhil Reid .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), 6079e8a32dSPhil Reid }; 6179e8a32dSPhil Reid 6279e8a32dSPhil Reid static int ad5272_write(struct ad5272_data *data, int reg, int val) 6379e8a32dSPhil Reid { 6479e8a32dSPhil Reid int ret; 6579e8a32dSPhil Reid 6679e8a32dSPhil Reid data->buf[0] = (reg << 2) | ((val >> 8) & 0x3); 6779e8a32dSPhil Reid data->buf[1] = (u8)val; 6879e8a32dSPhil Reid 6979e8a32dSPhil Reid mutex_lock(&data->lock); 7079e8a32dSPhil Reid ret = i2c_master_send(data->client, data->buf, sizeof(data->buf)); 7179e8a32dSPhil Reid mutex_unlock(&data->lock); 7279e8a32dSPhil Reid return ret < 0 ? ret : 0; 7379e8a32dSPhil Reid } 7479e8a32dSPhil Reid 7579e8a32dSPhil Reid static int ad5272_read(struct ad5272_data *data, int reg, int *val) 7679e8a32dSPhil Reid { 7779e8a32dSPhil Reid int ret; 7879e8a32dSPhil Reid 7979e8a32dSPhil Reid data->buf[0] = reg << 2; 8079e8a32dSPhil Reid data->buf[1] = 0; 8179e8a32dSPhil Reid 8279e8a32dSPhil Reid mutex_lock(&data->lock); 8379e8a32dSPhil Reid ret = i2c_master_send(data->client, data->buf, sizeof(data->buf)); 8479e8a32dSPhil Reid if (ret < 0) 8579e8a32dSPhil Reid goto error; 8679e8a32dSPhil Reid 8779e8a32dSPhil Reid ret = i2c_master_recv(data->client, data->buf, sizeof(data->buf)); 8879e8a32dSPhil Reid if (ret < 0) 8979e8a32dSPhil Reid goto error; 9079e8a32dSPhil Reid 9179e8a32dSPhil Reid *val = ((data->buf[0] & 0x3) << 8) | data->buf[1]; 9279e8a32dSPhil Reid ret = 0; 9379e8a32dSPhil Reid error: 9479e8a32dSPhil Reid mutex_unlock(&data->lock); 9579e8a32dSPhil Reid return ret; 9679e8a32dSPhil Reid } 9779e8a32dSPhil Reid 9879e8a32dSPhil Reid static int ad5272_read_raw(struct iio_dev *indio_dev, 9979e8a32dSPhil Reid struct iio_chan_spec const *chan, 10079e8a32dSPhil Reid int *val, int *val2, long mask) 10179e8a32dSPhil Reid { 10279e8a32dSPhil Reid struct ad5272_data *data = iio_priv(indio_dev); 10379e8a32dSPhil Reid int ret; 10479e8a32dSPhil Reid 10579e8a32dSPhil Reid switch (mask) { 10679e8a32dSPhil Reid case IIO_CHAN_INFO_RAW: { 10779e8a32dSPhil Reid ret = ad5272_read(data, AD5272_RDAC_RD, val); 10879e8a32dSPhil Reid *val = *val >> data->cfg->shift; 10979e8a32dSPhil Reid return ret ? ret : IIO_VAL_INT; 11079e8a32dSPhil Reid } 11179e8a32dSPhil Reid case IIO_CHAN_INFO_SCALE: 11279e8a32dSPhil Reid *val = 1000 * data->cfg->kohms; 11379e8a32dSPhil Reid *val2 = data->cfg->max_pos; 11479e8a32dSPhil Reid return IIO_VAL_FRACTIONAL; 11579e8a32dSPhil Reid } 11679e8a32dSPhil Reid 11779e8a32dSPhil Reid return -EINVAL; 11879e8a32dSPhil Reid } 11979e8a32dSPhil Reid 12079e8a32dSPhil Reid static int ad5272_write_raw(struct iio_dev *indio_dev, 12179e8a32dSPhil Reid struct iio_chan_spec const *chan, 12279e8a32dSPhil Reid int val, int val2, long mask) 12379e8a32dSPhil Reid { 12479e8a32dSPhil Reid struct ad5272_data *data = iio_priv(indio_dev); 12579e8a32dSPhil Reid 12679e8a32dSPhil Reid if (mask != IIO_CHAN_INFO_RAW) 12779e8a32dSPhil Reid return -EINVAL; 12879e8a32dSPhil Reid 12979e8a32dSPhil Reid if (val >= data->cfg->max_pos || val < 0 || val2) 13079e8a32dSPhil Reid return -EINVAL; 13179e8a32dSPhil Reid 13279e8a32dSPhil Reid return ad5272_write(data, AD5272_RDAC_WR, val << data->cfg->shift); 13379e8a32dSPhil Reid } 13479e8a32dSPhil Reid 13579e8a32dSPhil Reid static const struct iio_info ad5272_info = { 13679e8a32dSPhil Reid .read_raw = ad5272_read_raw, 13779e8a32dSPhil Reid .write_raw = ad5272_write_raw, 13879e8a32dSPhil Reid }; 13979e8a32dSPhil Reid 14079e8a32dSPhil Reid static int ad5272_reset(struct ad5272_data *data) 14179e8a32dSPhil Reid { 14279e8a32dSPhil Reid struct gpio_desc *reset_gpio; 14379e8a32dSPhil Reid 14479e8a32dSPhil Reid reset_gpio = devm_gpiod_get_optional(&data->client->dev, "reset", 14579e8a32dSPhil Reid GPIOD_OUT_LOW); 14679e8a32dSPhil Reid if (IS_ERR(reset_gpio)) 14779e8a32dSPhil Reid return PTR_ERR(reset_gpio); 14879e8a32dSPhil Reid 14979e8a32dSPhil Reid if (reset_gpio) { 15079e8a32dSPhil Reid udelay(1); 15179e8a32dSPhil Reid gpiod_set_value(reset_gpio, 1); 15279e8a32dSPhil Reid } else { 15379e8a32dSPhil Reid ad5272_write(data, AD5272_RESET, 0); 15479e8a32dSPhil Reid } 15579e8a32dSPhil Reid usleep_range(1000, 2000); 15679e8a32dSPhil Reid 15779e8a32dSPhil Reid return 0; 15879e8a32dSPhil Reid } 15979e8a32dSPhil Reid 16079e8a32dSPhil Reid static int ad5272_probe(struct i2c_client *client, 16179e8a32dSPhil Reid const struct i2c_device_id *id) 16279e8a32dSPhil Reid { 16379e8a32dSPhil Reid struct device *dev = &client->dev; 16479e8a32dSPhil Reid struct iio_dev *indio_dev; 16579e8a32dSPhil Reid struct ad5272_data *data; 16679e8a32dSPhil Reid int ret; 16779e8a32dSPhil Reid 16879e8a32dSPhil Reid indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 16979e8a32dSPhil Reid if (!indio_dev) 17079e8a32dSPhil Reid return -ENOMEM; 17179e8a32dSPhil Reid 17279e8a32dSPhil Reid i2c_set_clientdata(client, indio_dev); 17379e8a32dSPhil Reid 17479e8a32dSPhil Reid data = iio_priv(indio_dev); 17579e8a32dSPhil Reid data->client = client; 17679e8a32dSPhil Reid mutex_init(&data->lock); 17779e8a32dSPhil Reid data->cfg = &ad5272_cfg[id->driver_data]; 17879e8a32dSPhil Reid 17979e8a32dSPhil Reid ret = ad5272_reset(data); 18079e8a32dSPhil Reid if (ret) 18179e8a32dSPhil Reid return ret; 18279e8a32dSPhil Reid 18379e8a32dSPhil Reid ret = ad5272_write(data, AD5272_CTL, AD5272_RDAC_WR_EN); 18479e8a32dSPhil Reid if (ret < 0) 18579e8a32dSPhil Reid return -ENODEV; 18679e8a32dSPhil Reid 18779e8a32dSPhil Reid indio_dev->dev.parent = dev; 18879e8a32dSPhil Reid indio_dev->info = &ad5272_info; 18979e8a32dSPhil Reid indio_dev->channels = &ad5272_channel; 19079e8a32dSPhil Reid indio_dev->num_channels = 1; 19179e8a32dSPhil Reid indio_dev->name = client->name; 19279e8a32dSPhil Reid 19379e8a32dSPhil Reid return devm_iio_device_register(dev, indio_dev); 19479e8a32dSPhil Reid } 19579e8a32dSPhil Reid 19679e8a32dSPhil Reid #if defined(CONFIG_OF) 19779e8a32dSPhil Reid static const struct of_device_id ad5272_dt_ids[] = { 19879e8a32dSPhil Reid { .compatible = "adi,ad5272-020", .data = (void *)AD5272_020 }, 19979e8a32dSPhil Reid { .compatible = "adi,ad5272-050", .data = (void *)AD5272_050 }, 20079e8a32dSPhil Reid { .compatible = "adi,ad5272-100", .data = (void *)AD5272_100 }, 20179e8a32dSPhil Reid { .compatible = "adi,ad5274-020", .data = (void *)AD5274_020 }, 20279e8a32dSPhil Reid { .compatible = "adi,ad5274-100", .data = (void *)AD5274_100 }, 20379e8a32dSPhil Reid {} 20479e8a32dSPhil Reid }; 20579e8a32dSPhil Reid MODULE_DEVICE_TABLE(of, ad5272_dt_ids); 20679e8a32dSPhil Reid #endif /* CONFIG_OF */ 20779e8a32dSPhil Reid 20879e8a32dSPhil Reid static const struct i2c_device_id ad5272_id[] = { 20979e8a32dSPhil Reid { "ad5272-020", AD5272_020 }, 21079e8a32dSPhil Reid { "ad5272-050", AD5272_050 }, 21179e8a32dSPhil Reid { "ad5272-100", AD5272_100 }, 21279e8a32dSPhil Reid { "ad5274-020", AD5274_020 }, 21379e8a32dSPhil Reid { "ad5274-100", AD5274_100 }, 21479e8a32dSPhil Reid {} 21579e8a32dSPhil Reid }; 21679e8a32dSPhil Reid MODULE_DEVICE_TABLE(i2c, ad5272_id); 21779e8a32dSPhil Reid 21879e8a32dSPhil Reid static struct i2c_driver ad5272_driver = { 21979e8a32dSPhil Reid .driver = { 22079e8a32dSPhil Reid .name = "ad5272", 22179e8a32dSPhil Reid .of_match_table = of_match_ptr(ad5272_dt_ids), 22279e8a32dSPhil Reid }, 22379e8a32dSPhil Reid .probe = ad5272_probe, 22479e8a32dSPhil Reid .id_table = ad5272_id, 22579e8a32dSPhil Reid }; 22679e8a32dSPhil Reid 22779e8a32dSPhil Reid module_i2c_driver(ad5272_driver); 22879e8a32dSPhil Reid 22979e8a32dSPhil Reid MODULE_AUTHOR("Phil Reid <preid@eletromag.com.au>"); 23079e8a32dSPhil Reid MODULE_DESCRIPTION("AD5272 digital potentiometer"); 23179e8a32dSPhil Reid MODULE_LICENSE("GPL v2"); 232