^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Driver for Linear Technology LTC2471 and LTC2473 voltage monitors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * The LTC2473 is identical to the 2471, but reports a differential signal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Copyright (C) 2017 Topic Embedded Products
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Author: Mike Looijmans <mike.looijmans@topic.nl>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/iio/iio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/iio/sysfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) enum ltc2471_chips {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) ltc2471,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) ltc2473,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) struct ltc2471_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) struct i2c_client *client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) /* Reference voltage is 1.25V */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #define LTC2471_VREF 1250
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) /* Read two bytes from the I2C bus to obtain the ADC result */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) static int ltc2471_get_value(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) __be16 buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) ret = i2c_master_recv(client, (char *)&buf, sizeof(buf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) if (ret != sizeof(buf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) /* MSB first */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) return be16_to_cpu(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) static int ltc2471_read_raw(struct iio_dev *indio_dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) struct iio_chan_spec const *chan,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) int *val, int *val2, long info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) struct ltc2471_data *data = iio_priv(indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) switch (info) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) case IIO_CHAN_INFO_RAW:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) ret = ltc2471_get_value(data->client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) *val = ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) return IIO_VAL_INT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) case IIO_CHAN_INFO_SCALE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) if (chan->differential)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) /* Output ranges from -VREF to +VREF */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) *val = 2 * LTC2471_VREF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) /* Output ranges from 0 to VREF */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) *val = LTC2471_VREF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) *val2 = 16; /* 16 data bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) return IIO_VAL_FRACTIONAL_LOG2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) case IIO_CHAN_INFO_OFFSET:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) /* Only differential chip has this property */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) *val = -LTC2471_VREF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) return IIO_VAL_INT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) static const struct iio_chan_spec ltc2471_channel[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) .type = IIO_VOLTAGE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) static const struct iio_chan_spec ltc2473_channel[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) .type = IIO_VOLTAGE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) BIT(IIO_CHAN_INFO_OFFSET),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) .differential = 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) static const struct iio_info ltc2471_info = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) .read_raw = ltc2471_read_raw,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) static int ltc2471_i2c_probe(struct i2c_client *client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) const struct i2c_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) struct iio_dev *indio_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) struct ltc2471_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) return -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (!indio_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) data = iio_priv(indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) data->client = client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) indio_dev->name = id->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) indio_dev->info = <c2471_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) indio_dev->modes = INDIO_DIRECT_MODE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (id->driver_data == ltc2473)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) indio_dev->channels = ltc2473_channel;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) indio_dev->channels = ltc2471_channel;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) indio_dev->num_channels = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) /* Trigger once to start conversion and check if chip is there */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) ret = ltc2471_get_value(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) dev_err(&client->dev, "Cannot read from device.\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) return devm_iio_device_register(&client->dev, indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) static const struct i2c_device_id ltc2471_i2c_id[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) { "ltc2471", ltc2471 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) { "ltc2473", ltc2473 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) {}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) MODULE_DEVICE_TABLE(i2c, ltc2471_i2c_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) static struct i2c_driver ltc2471_i2c_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) .name = "ltc2471",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) .probe = ltc2471_i2c_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) .id_table = ltc2471_i2c_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) module_i2c_driver(ltc2471_i2c_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) MODULE_DESCRIPTION("LTC2471/LTC2473 ADC driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) MODULE_AUTHOR("Topic Embedded Products");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags