Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 1 | /* |
| 2 | * Industrial I/O driver for Microchip digital potentiometers |
| 3 | * Copyright (c) 2015 Axentia Technologies AB |
| 4 | * Author: Peter Rosin <peda@axentia.se> |
| 5 | * |
| 6 | * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22096b.pdf |
| 7 | * |
| 8 | * DEVID #Wipers #Positions Resistor Opts (kOhm) i2c address |
| 9 | * mcp4531 1 129 5, 10, 50, 100 010111x |
| 10 | * mcp4532 1 129 5, 10, 50, 100 01011xx |
| 11 | * mcp4551 1 257 5, 10, 50, 100 010111x |
| 12 | * mcp4552 1 257 5, 10, 50, 100 01011xx |
| 13 | * mcp4631 2 129 5, 10, 50, 100 0101xxx |
| 14 | * mcp4632 2 129 5, 10, 50, 100 01011xx |
| 15 | * mcp4651 2 257 5, 10, 50, 100 0101xxx |
| 16 | * mcp4652 2 257 5, 10, 50, 100 01011xx |
| 17 | * |
| 18 | * This program is free software; you can redistribute it and/or modify it |
| 19 | * under the terms of the GNU General Public License version 2 as published by |
| 20 | * the Free Software Foundation. |
| 21 | */ |
| 22 | |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/i2c.h> |
| 25 | #include <linux/err.h> |
| 26 | |
| 27 | #include <linux/iio/iio.h> |
| 28 | |
| 29 | struct mcp4531_cfg { |
| 30 | int wipers; |
| 31 | int max_pos; |
| 32 | int kohms; |
| 33 | }; |
| 34 | |
| 35 | enum mcp4531_type { |
| 36 | MCP453x_502, |
| 37 | MCP453x_103, |
| 38 | MCP453x_503, |
| 39 | MCP453x_104, |
| 40 | MCP455x_502, |
| 41 | MCP455x_103, |
| 42 | MCP455x_503, |
| 43 | MCP455x_104, |
| 44 | MCP463x_502, |
| 45 | MCP463x_103, |
| 46 | MCP463x_503, |
| 47 | MCP463x_104, |
| 48 | MCP465x_502, |
| 49 | MCP465x_103, |
| 50 | MCP465x_503, |
| 51 | MCP465x_104, |
| 52 | }; |
| 53 | |
| 54 | static const struct mcp4531_cfg mcp4531_cfg[] = { |
| 55 | [MCP453x_502] = { .wipers = 1, .max_pos = 128, .kohms = 5, }, |
| 56 | [MCP453x_103] = { .wipers = 1, .max_pos = 128, .kohms = 10, }, |
| 57 | [MCP453x_503] = { .wipers = 1, .max_pos = 128, .kohms = 50, }, |
| 58 | [MCP453x_104] = { .wipers = 1, .max_pos = 128, .kohms = 100, }, |
| 59 | [MCP455x_502] = { .wipers = 1, .max_pos = 256, .kohms = 5, }, |
| 60 | [MCP455x_103] = { .wipers = 1, .max_pos = 256, .kohms = 10, }, |
| 61 | [MCP455x_503] = { .wipers = 1, .max_pos = 256, .kohms = 50, }, |
| 62 | [MCP455x_104] = { .wipers = 1, .max_pos = 256, .kohms = 100, }, |
| 63 | [MCP463x_502] = { .wipers = 2, .max_pos = 128, .kohms = 5, }, |
| 64 | [MCP463x_103] = { .wipers = 2, .max_pos = 128, .kohms = 10, }, |
| 65 | [MCP463x_503] = { .wipers = 2, .max_pos = 128, .kohms = 50, }, |
| 66 | [MCP463x_104] = { .wipers = 2, .max_pos = 128, .kohms = 100, }, |
| 67 | [MCP465x_502] = { .wipers = 2, .max_pos = 256, .kohms = 5, }, |
| 68 | [MCP465x_103] = { .wipers = 2, .max_pos = 256, .kohms = 10, }, |
| 69 | [MCP465x_503] = { .wipers = 2, .max_pos = 256, .kohms = 50, }, |
| 70 | [MCP465x_104] = { .wipers = 2, .max_pos = 256, .kohms = 100, }, |
| 71 | }; |
| 72 | |
| 73 | #define MCP4531_WRITE (0 << 2) |
| 74 | #define MCP4531_INCR (1 << 2) |
| 75 | #define MCP4531_DECR (2 << 2) |
| 76 | #define MCP4531_READ (3 << 2) |
| 77 | |
| 78 | #define MCP4531_WIPER_SHIFT (4) |
| 79 | |
| 80 | struct mcp4531_data { |
| 81 | struct i2c_client *client; |
| 82 | unsigned long devid; |
| 83 | }; |
| 84 | |
| 85 | #define MCP4531_CHANNEL(ch) { \ |
| 86 | .type = IIO_RESISTANCE, \ |
| 87 | .indexed = 1, \ |
| 88 | .output = 1, \ |
| 89 | .channel = (ch), \ |
| 90 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
| 91 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
| 92 | } |
| 93 | |
| 94 | static const struct iio_chan_spec mcp4531_channels[] = { |
| 95 | MCP4531_CHANNEL(0), |
| 96 | MCP4531_CHANNEL(1), |
| 97 | }; |
| 98 | |
| 99 | static int mcp4531_read_raw(struct iio_dev *indio_dev, |
| 100 | struct iio_chan_spec const *chan, |
| 101 | int *val, int *val2, long mask) |
| 102 | { |
| 103 | struct mcp4531_data *data = iio_priv(indio_dev); |
| 104 | int address = chan->channel << MCP4531_WIPER_SHIFT; |
| 105 | s32 ret; |
| 106 | |
| 107 | switch (mask) { |
| 108 | case IIO_CHAN_INFO_RAW: |
| 109 | ret = i2c_smbus_read_word_swapped(data->client, |
| 110 | MCP4531_READ | address); |
| 111 | if (ret < 0) |
| 112 | return ret; |
| 113 | *val = ret; |
| 114 | return IIO_VAL_INT; |
| 115 | case IIO_CHAN_INFO_SCALE: |
| 116 | *val = 1000 * mcp4531_cfg[data->devid].kohms; |
| 117 | *val2 = mcp4531_cfg[data->devid].max_pos; |
| 118 | return IIO_VAL_FRACTIONAL; |
| 119 | } |
| 120 | |
| 121 | return -EINVAL; |
| 122 | } |
| 123 | |
| 124 | static int mcp4531_write_raw(struct iio_dev *indio_dev, |
| 125 | struct iio_chan_spec const *chan, |
| 126 | int val, int val2, long mask) |
| 127 | { |
| 128 | struct mcp4531_data *data = iio_priv(indio_dev); |
| 129 | int address = chan->channel << MCP4531_WIPER_SHIFT; |
| 130 | |
| 131 | switch (mask) { |
| 132 | case IIO_CHAN_INFO_RAW: |
| 133 | if (val > mcp4531_cfg[data->devid].max_pos || val < 0) |
| 134 | return -EINVAL; |
| 135 | break; |
| 136 | default: |
| 137 | return -EINVAL; |
| 138 | } |
| 139 | |
| 140 | return i2c_smbus_write_byte_data(data->client, |
| 141 | MCP4531_WRITE | address | (val >> 8), |
| 142 | val & 0xff); |
| 143 | } |
| 144 | |
| 145 | static const struct iio_info mcp4531_info = { |
| 146 | .read_raw = mcp4531_read_raw, |
| 147 | .write_raw = mcp4531_write_raw, |
| 148 | .driver_module = THIS_MODULE, |
| 149 | }; |
| 150 | |
| 151 | static int mcp4531_probe(struct i2c_client *client, |
| 152 | const struct i2c_device_id *id) |
| 153 | { |
| 154 | struct device *dev = &client->dev; |
| 155 | unsigned long devid = id->driver_data; |
| 156 | struct mcp4531_data *data; |
| 157 | struct iio_dev *indio_dev; |
| 158 | |
| 159 | if (!i2c_check_functionality(client->adapter, |
| 160 | I2C_FUNC_SMBUS_WORD_DATA)) { |
| 161 | dev_err(dev, "SMBUS Word Data not supported\n"); |
| 162 | return -EIO; |
| 163 | } |
| 164 | |
| 165 | indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); |
| 166 | if (!indio_dev) |
| 167 | return -ENOMEM; |
| 168 | data = iio_priv(indio_dev); |
| 169 | i2c_set_clientdata(client, indio_dev); |
| 170 | data->client = client; |
| 171 | data->devid = devid; |
| 172 | |
| 173 | indio_dev->dev.parent = dev; |
| 174 | indio_dev->info = &mcp4531_info; |
| 175 | indio_dev->channels = mcp4531_channels; |
| 176 | indio_dev->num_channels = mcp4531_cfg[devid].wipers; |
| 177 | indio_dev->name = client->name; |
| 178 | |
| 179 | return devm_iio_device_register(dev, indio_dev); |
| 180 | } |
| 181 | |
| 182 | static const struct i2c_device_id mcp4531_id[] = { |
| 183 | { "mcp4531-502", MCP453x_502 }, |
| 184 | { "mcp4531-103", MCP453x_103 }, |
| 185 | { "mcp4531-503", MCP453x_503 }, |
| 186 | { "mcp4531-104", MCP453x_104 }, |
| 187 | { "mcp4532-502", MCP453x_502 }, |
| 188 | { "mcp4532-103", MCP453x_103 }, |
| 189 | { "mcp4532-503", MCP453x_503 }, |
| 190 | { "mcp4532-104", MCP453x_104 }, |
| 191 | { "mcp4551-502", MCP455x_502 }, |
| 192 | { "mcp4551-103", MCP455x_103 }, |
| 193 | { "mcp4551-503", MCP455x_503 }, |
| 194 | { "mcp4551-104", MCP455x_104 }, |
| 195 | { "mcp4552-502", MCP455x_502 }, |
| 196 | { "mcp4552-103", MCP455x_103 }, |
| 197 | { "mcp4552-503", MCP455x_503 }, |
| 198 | { "mcp4552-104", MCP455x_104 }, |
| 199 | { "mcp4631-502", MCP463x_502 }, |
| 200 | { "mcp4631-103", MCP463x_103 }, |
| 201 | { "mcp4631-503", MCP463x_503 }, |
| 202 | { "mcp4631-104", MCP463x_104 }, |
| 203 | { "mcp4632-502", MCP463x_502 }, |
| 204 | { "mcp4632-103", MCP463x_103 }, |
| 205 | { "mcp4632-503", MCP463x_503 }, |
| 206 | { "mcp4632-104", MCP463x_104 }, |
| 207 | { "mcp4651-502", MCP465x_502 }, |
| 208 | { "mcp4651-103", MCP465x_103 }, |
| 209 | { "mcp4651-503", MCP465x_503 }, |
| 210 | { "mcp4651-104", MCP465x_104 }, |
| 211 | { "mcp4652-502", MCP465x_502 }, |
| 212 | { "mcp4652-103", MCP465x_103 }, |
| 213 | { "mcp4652-503", MCP465x_503 }, |
| 214 | { "mcp4652-104", MCP465x_104 }, |
| 215 | {} |
| 216 | }; |
| 217 | MODULE_DEVICE_TABLE(i2c, mcp4531_id); |
| 218 | |
| 219 | static struct i2c_driver mcp4531_driver = { |
| 220 | .driver = { |
| 221 | .name = "mcp4531", |
| 222 | }, |
| 223 | .probe = mcp4531_probe, |
| 224 | .id_table = mcp4531_id, |
| 225 | }; |
| 226 | |
| 227 | module_i2c_driver(mcp4531_driver); |
| 228 | |
| 229 | MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); |
| 230 | MODULE_DESCRIPTION("MCP4531 digital potentiometer"); |
| 231 | MODULE_LICENSE("GPL"); |