^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) * ltc2485.c - Driver for Linear Technology LTC2485 ADC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2016 Alison Schofield <amsfield22@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Datasheet: http://cds.linear.com/docs/en/datasheet/2485fd.pdf
^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/delay.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/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^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) /* Power-on configuration: rejects both 50/60Hz, operates at 1x speed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #define LTC2485_CONFIG_DEFAULT 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) struct ltc2485_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) struct i2c_client *client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) ktime_t time_prev; /* last conversion */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static void ltc2485_wait_conv(struct ltc2485_data *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) const unsigned int conv_time = 147; /* conversion time ms */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) unsigned int time_elapsed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /* delay if conversion time not passed since last read or write */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) time_elapsed = ktime_ms_delta(ktime_get(), data->time_prev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) if (time_elapsed < conv_time)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) msleep(conv_time - time_elapsed);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static int ltc2485_read(struct ltc2485_data *data, int *val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) struct i2c_client *client = data->client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) __be32 buf = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) ltc2485_wait_conv(data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) ret = i2c_master_recv(client, (char *)&buf, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) dev_err(&client->dev, "i2c_master_recv failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) data->time_prev = ktime_get();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) *val = sign_extend32(be32_to_cpu(buf) >> 6, 24);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) static int ltc2485_read_raw(struct iio_dev *indio_dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) struct iio_chan_spec const *chan,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) int *val, int *val2, long mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) struct ltc2485_data *data = iio_priv(indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) if (mask == IIO_CHAN_INFO_RAW) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) ret = ltc2485_read(data, val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) return IIO_VAL_INT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) } else if (mask == IIO_CHAN_INFO_SCALE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) *val = 5000; /* on board vref millivolts */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) *val2 = 25; /* 25 (24 + sign) data bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) return IIO_VAL_FRACTIONAL_LOG2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) } else {
^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 ltc2485_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_info ltc2485_info = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) .read_raw = ltc2485_read_raw,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) static int ltc2485_probe(struct i2c_client *client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) const struct i2c_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) struct iio_dev *indio_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) struct ltc2485_data *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) I2C_FUNC_SMBUS_WRITE_BYTE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) return -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) if (!indio_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) data = iio_priv(indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) i2c_set_clientdata(client, indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) data->client = client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) indio_dev->name = id->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) indio_dev->info = <c2485_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) indio_dev->modes = INDIO_DIRECT_MODE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) indio_dev->channels = ltc2485_channel;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) indio_dev->num_channels = ARRAY_SIZE(ltc2485_channel);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) ret = i2c_smbus_write_byte(data->client, LTC2485_CONFIG_DEFAULT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) data->time_prev = ktime_get();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) return devm_iio_device_register(&client->dev, indio_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) static const struct i2c_device_id ltc2485_id[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) { "ltc2485", 0 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) MODULE_DEVICE_TABLE(i2c, ltc2485_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) static struct i2c_driver ltc2485_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) .name = "ltc2485",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) .probe = ltc2485_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) .id_table = ltc2485_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) module_i2c_driver(ltc2485_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) MODULE_AUTHOR("Alison Schofield <amsfield22@gmail.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) MODULE_DESCRIPTION("Linear Technology LTC2485 ADC driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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