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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | // SPDX-License-Identifier: GPL-2.0 /* * Industrial I/O driver for Microchip digital potentiometers * Copyright (c) 2018 Axentia Technologies AB * Author: Peter Rosin <peda@axentia.se> * * Datasheet: http://www.microchip.com/downloads/en/DeviceDoc/22147a.pdf * * DEVID #Wipers #Positions Resistor Opts (kOhm) * mcp4017 1 128 5, 10, 50, 100 * mcp4018 1 128 5, 10, 50, 100 * mcp4019 1 128 5, 10, 50, 100 */ #include <linux/err.h> #include <linux/i2c.h> #include <linux/iio/iio.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #define MCP4018_WIPER_MAX 127 struct mcp4018_cfg { int kohms; }; enum mcp4018_type { MCP4018_502, MCP4018_103, MCP4018_503, MCP4018_104, }; static const struct mcp4018_cfg mcp4018_cfg[] = { [MCP4018_502] = { .kohms = 5, }, [MCP4018_103] = { .kohms = 10, }, [MCP4018_503] = { .kohms = 50, }, [MCP4018_104] = { .kohms = 100, }, }; struct mcp4018_data { struct i2c_client *client; const struct mcp4018_cfg *cfg; }; static const struct iio_chan_spec mcp4018_channel = { .type = IIO_RESISTANCE, .indexed = 1, .output = 1, .channel = 0, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), }; static int mcp4018_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct mcp4018_data *data = iio_priv(indio_dev); s32 ret; switch (mask) { case IIO_CHAN_INFO_RAW: ret = i2c_smbus_read_byte(data->client); if (ret < 0) return ret; *val = ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 1000 * data->cfg->kohms; *val2 = MCP4018_WIPER_MAX; return IIO_VAL_FRACTIONAL; } return -EINVAL; } static int mcp4018_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct mcp4018_data *data = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_RAW: if (val > MCP4018_WIPER_MAX || val < 0) return -EINVAL; break; default: return -EINVAL; } return i2c_smbus_write_byte(data->client, val); } static const struct iio_info mcp4018_info = { .read_raw = mcp4018_read_raw, .write_raw = mcp4018_write_raw, }; static const struct i2c_device_id mcp4018_id[] = { { "mcp4017-502", MCP4018_502 }, { "mcp4017-103", MCP4018_103 }, { "mcp4017-503", MCP4018_503 }, { "mcp4017-104", MCP4018_104 }, { "mcp4018-502", MCP4018_502 }, { "mcp4018-103", MCP4018_103 }, { "mcp4018-503", MCP4018_503 }, { "mcp4018-104", MCP4018_104 }, { "mcp4019-502", MCP4018_502 }, { "mcp4019-103", MCP4018_103 }, { "mcp4019-503", MCP4018_503 }, { "mcp4019-104", MCP4018_104 }, {} }; MODULE_DEVICE_TABLE(i2c, mcp4018_id); #ifdef CONFIG_OF #define MCP4018_COMPATIBLE(of_compatible, cfg) { \ .compatible = of_compatible, \ .data = &mcp4018_cfg[cfg], \ } static const struct of_device_id mcp4018_of_match[] = { MCP4018_COMPATIBLE("microchip,mcp4017-502", MCP4018_502), MCP4018_COMPATIBLE("microchip,mcp4017-103", MCP4018_103), MCP4018_COMPATIBLE("microchip,mcp4017-503", MCP4018_503), MCP4018_COMPATIBLE("microchip,mcp4017-104", MCP4018_104), MCP4018_COMPATIBLE("microchip,mcp4018-502", MCP4018_502), MCP4018_COMPATIBLE("microchip,mcp4018-103", MCP4018_103), MCP4018_COMPATIBLE("microchip,mcp4018-503", MCP4018_503), MCP4018_COMPATIBLE("microchip,mcp4018-104", MCP4018_104), MCP4018_COMPATIBLE("microchip,mcp4019-502", MCP4018_502), MCP4018_COMPATIBLE("microchip,mcp4019-103", MCP4018_103), MCP4018_COMPATIBLE("microchip,mcp4019-503", MCP4018_503), MCP4018_COMPATIBLE("microchip,mcp4019-104", MCP4018_104), { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, mcp4018_of_match); #endif static int mcp4018_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct mcp4018_data *data; struct iio_dev *indio_dev; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) { dev_err(dev, "SMBUS Byte transfers not supported\n"); return -EOPNOTSUPP; } indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; data = iio_priv(indio_dev); i2c_set_clientdata(client, indio_dev); data->client = client; data->cfg = of_device_get_match_data(dev); if (!data->cfg) data->cfg = &mcp4018_cfg[i2c_match_id(mcp4018_id, client)->driver_data]; indio_dev->dev.parent = dev; indio_dev->info = &mcp4018_info; indio_dev->channels = &mcp4018_channel; indio_dev->num_channels = 1; indio_dev->name = client->name; return devm_iio_device_register(dev, indio_dev); } static struct i2c_driver mcp4018_driver = { .driver = { .name = "mcp4018", .of_match_table = of_match_ptr(mcp4018_of_match), }, .probe_new = mcp4018_probe, .id_table = mcp4018_id, }; module_i2c_driver(mcp4018_driver); MODULE_AUTHOR("Peter Rosin <peda@axentia.se>"); MODULE_DESCRIPTION("MCP4018 digital potentiometer"); MODULE_LICENSE("GPL v2"); |