Thierry Reding | bc0a409 | 2012-11-23 15:13:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 Avionic Design GmbH |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/err.h> |
| 10 | #include <linux/i2c.h> |
| 11 | #include <linux/module.h> |
| 12 | |
| 13 | #include <linux/iio/iio.h> |
| 14 | #include <linux/regulator/consumer.h> |
| 15 | |
| 16 | struct adc081c { |
| 17 | struct i2c_client *i2c; |
| 18 | struct regulator *ref; |
| 19 | }; |
| 20 | |
| 21 | #define REG_CONV_RES 0x00 |
| 22 | |
| 23 | static int adc081c_read_raw(struct iio_dev *iio, |
| 24 | struct iio_chan_spec const *channel, int *value, |
| 25 | int *shift, long mask) |
| 26 | { |
| 27 | struct adc081c *adc = iio_priv(iio); |
| 28 | int err; |
| 29 | |
| 30 | switch (mask) { |
| 31 | case IIO_CHAN_INFO_RAW: |
| 32 | err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES); |
| 33 | if (err < 0) |
| 34 | return err; |
| 35 | |
| 36 | *value = (err >> 4) & 0xff; |
| 37 | return IIO_VAL_INT; |
| 38 | |
| 39 | case IIO_CHAN_INFO_SCALE: |
| 40 | err = regulator_get_voltage(adc->ref); |
| 41 | if (err < 0) |
| 42 | return err; |
| 43 | |
| 44 | *value = err / 1000; |
| 45 | *shift = 8; |
| 46 | |
| 47 | return IIO_VAL_FRACTIONAL_LOG2; |
| 48 | |
| 49 | default: |
| 50 | break; |
| 51 | } |
| 52 | |
| 53 | return -EINVAL; |
| 54 | } |
| 55 | |
| 56 | static const struct iio_chan_spec adc081c_channel = { |
| 57 | .type = IIO_VOLTAGE, |
Jonathan Cameron | c8fe38a | 2013-02-27 19:06:39 +0000 | [diff] [blame] | 58 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
| 59 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
Thierry Reding | bc0a409 | 2012-11-23 15:13:00 +0000 | [diff] [blame] | 60 | }; |
| 61 | |
| 62 | static const struct iio_info adc081c_info = { |
| 63 | .read_raw = adc081c_read_raw, |
| 64 | .driver_module = THIS_MODULE, |
| 65 | }; |
| 66 | |
| 67 | static int adc081c_probe(struct i2c_client *client, |
| 68 | const struct i2c_device_id *id) |
| 69 | { |
| 70 | struct iio_dev *iio; |
| 71 | struct adc081c *adc; |
| 72 | int err; |
| 73 | |
| 74 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) |
| 75 | return -ENODEV; |
| 76 | |
Sachin Kamat | 99e94b6 | 2013-07-23 09:58:00 +0100 | [diff] [blame] | 77 | iio = devm_iio_device_alloc(&client->dev, sizeof(*adc)); |
Thierry Reding | bc0a409 | 2012-11-23 15:13:00 +0000 | [diff] [blame] | 78 | if (!iio) |
| 79 | return -ENOMEM; |
| 80 | |
| 81 | adc = iio_priv(iio); |
| 82 | adc->i2c = client; |
| 83 | |
Sachin Kamat | 99e94b6 | 2013-07-23 09:58:00 +0100 | [diff] [blame] | 84 | adc->ref = devm_regulator_get(&client->dev, "vref"); |
| 85 | if (IS_ERR(adc->ref)) |
| 86 | return PTR_ERR(adc->ref); |
Thierry Reding | bc0a409 | 2012-11-23 15:13:00 +0000 | [diff] [blame] | 87 | |
| 88 | err = regulator_enable(adc->ref); |
| 89 | if (err < 0) |
Sachin Kamat | 99e94b6 | 2013-07-23 09:58:00 +0100 | [diff] [blame] | 90 | return err; |
Thierry Reding | bc0a409 | 2012-11-23 15:13:00 +0000 | [diff] [blame] | 91 | |
| 92 | iio->dev.parent = &client->dev; |
| 93 | iio->name = dev_name(&client->dev); |
| 94 | iio->modes = INDIO_DIRECT_MODE; |
| 95 | iio->info = &adc081c_info; |
| 96 | |
| 97 | iio->channels = &adc081c_channel; |
| 98 | iio->num_channels = 1; |
| 99 | |
| 100 | err = iio_device_register(iio); |
| 101 | if (err < 0) |
| 102 | goto regulator_disable; |
| 103 | |
| 104 | i2c_set_clientdata(client, iio); |
| 105 | |
| 106 | return 0; |
| 107 | |
| 108 | regulator_disable: |
| 109 | regulator_disable(adc->ref); |
Thierry Reding | bc0a409 | 2012-11-23 15:13:00 +0000 | [diff] [blame] | 110 | |
| 111 | return err; |
| 112 | } |
| 113 | |
| 114 | static int adc081c_remove(struct i2c_client *client) |
| 115 | { |
| 116 | struct iio_dev *iio = i2c_get_clientdata(client); |
| 117 | struct adc081c *adc = iio_priv(iio); |
| 118 | |
| 119 | iio_device_unregister(iio); |
| 120 | regulator_disable(adc->ref); |
Thierry Reding | bc0a409 | 2012-11-23 15:13:00 +0000 | [diff] [blame] | 121 | |
| 122 | return 0; |
| 123 | } |
| 124 | |
| 125 | static const struct i2c_device_id adc081c_id[] = { |
| 126 | { "adc081c", 0 }, |
| 127 | { } |
| 128 | }; |
| 129 | MODULE_DEVICE_TABLE(i2c, adc081c_id); |
| 130 | |
| 131 | #ifdef CONFIG_OF |
| 132 | static const struct of_device_id adc081c_of_match[] = { |
| 133 | { .compatible = "ti,adc081c" }, |
| 134 | { } |
| 135 | }; |
| 136 | MODULE_DEVICE_TABLE(of, adc081c_of_match); |
| 137 | #endif |
| 138 | |
| 139 | static struct i2c_driver adc081c_driver = { |
| 140 | .driver = { |
| 141 | .name = "adc081c", |
| 142 | .owner = THIS_MODULE, |
| 143 | .of_match_table = of_match_ptr(adc081c_of_match), |
| 144 | }, |
| 145 | .probe = adc081c_probe, |
| 146 | .remove = adc081c_remove, |
| 147 | .id_table = adc081c_id, |
| 148 | }; |
| 149 | module_i2c_driver(adc081c_driver); |
| 150 | |
| 151 | MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); |
| 152 | MODULE_DESCRIPTION("Texas Instruments ADC081C021/027 driver"); |
| 153 | MODULE_LICENSE("GPL v2"); |