1 /* 2 * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver 3 * 4 * Copyright (C) 2012 Avionic Design GmbH 5 * Copyright (C) 2016 Intel 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * Datasheets: 12 * http://www.ti.com/lit/ds/symlink/adc081c021.pdf 13 * http://www.ti.com/lit/ds/symlink/adc101c021.pdf 14 * http://www.ti.com/lit/ds/symlink/adc121c021.pdf 15 * 16 * The devices have a very similar interface and differ mostly in the number of 17 * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2 18 * bits of value registers are reserved. 19 */ 20 21 #include <linux/err.h> 22 #include <linux/i2c.h> 23 #include <linux/module.h> 24 #include <linux/of.h> 25 #include <linux/acpi.h> 26 27 #include <linux/iio/iio.h> 28 #include <linux/iio/buffer.h> 29 #include <linux/iio/trigger_consumer.h> 30 #include <linux/iio/triggered_buffer.h> 31 #include <linux/regulator/consumer.h> 32 33 struct adc081c { 34 struct i2c_client *i2c; 35 struct regulator *ref; 36 37 /* 8, 10 or 12 */ 38 int bits; 39 }; 40 41 #define REG_CONV_RES 0x00 42 43 static int adc081c_read_raw(struct iio_dev *iio, 44 struct iio_chan_spec const *channel, int *value, 45 int *shift, long mask) 46 { 47 struct adc081c *adc = iio_priv(iio); 48 int err; 49 50 switch (mask) { 51 case IIO_CHAN_INFO_RAW: 52 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES); 53 if (err < 0) 54 return err; 55 56 *value = (err & 0xFFF) >> (12 - adc->bits); 57 return IIO_VAL_INT; 58 59 case IIO_CHAN_INFO_SCALE: 60 err = regulator_get_voltage(adc->ref); 61 if (err < 0) 62 return err; 63 64 *value = err / 1000; 65 *shift = adc->bits; 66 67 return IIO_VAL_FRACTIONAL_LOG2; 68 69 default: 70 break; 71 } 72 73 return -EINVAL; 74 } 75 76 #define ADCxx1C_CHAN(_bits) { \ 77 .type = IIO_VOLTAGE, \ 78 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 79 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 80 .scan_type = { \ 81 .sign = 'u', \ 82 .realbits = (_bits), \ 83 .storagebits = 16, \ 84 .shift = 12 - (_bits), \ 85 .endianness = IIO_CPU, \ 86 }, \ 87 } 88 89 #define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \ 90 static const struct iio_chan_spec _name ## _channels[] = { \ 91 ADCxx1C_CHAN((_bits)), \ 92 IIO_CHAN_SOFT_TIMESTAMP(1), \ 93 }; \ 94 95 #define ADC081C_NUM_CHANNELS 2 96 97 struct adcxx1c_model { 98 const struct iio_chan_spec* channels; 99 int bits; 100 }; 101 102 #define ADCxx1C_MODEL(_name, _bits) \ 103 { \ 104 .channels = _name ## _channels, \ 105 .bits = (_bits), \ 106 } 107 108 DEFINE_ADCxx1C_CHANNELS(adc081c, 8); 109 DEFINE_ADCxx1C_CHANNELS(adc101c, 10); 110 DEFINE_ADCxx1C_CHANNELS(adc121c, 12); 111 112 /* Model ids are indexes in _models array */ 113 enum adcxx1c_model_id { 114 ADC081C = 0, 115 ADC101C = 1, 116 ADC121C = 2, 117 }; 118 119 static struct adcxx1c_model adcxx1c_models[] = { 120 ADCxx1C_MODEL(adc081c, 8), 121 ADCxx1C_MODEL(adc101c, 10), 122 ADCxx1C_MODEL(adc121c, 12), 123 }; 124 125 static const struct iio_info adc081c_info = { 126 .read_raw = adc081c_read_raw, 127 }; 128 129 static irqreturn_t adc081c_trigger_handler(int irq, void *p) 130 { 131 struct iio_poll_func *pf = p; 132 struct iio_dev *indio_dev = pf->indio_dev; 133 struct adc081c *data = iio_priv(indio_dev); 134 u16 buf[8]; /* 2 bytes data + 6 bytes padding + 8 bytes timestamp */ 135 int ret; 136 137 ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES); 138 if (ret < 0) 139 goto out; 140 buf[0] = ret; 141 iio_push_to_buffers_with_timestamp(indio_dev, buf, 142 iio_get_time_ns(indio_dev)); 143 out: 144 iio_trigger_notify_done(indio_dev->trig); 145 return IRQ_HANDLED; 146 } 147 148 static int adc081c_probe(struct i2c_client *client, 149 const struct i2c_device_id *id) 150 { 151 struct iio_dev *iio; 152 struct adc081c *adc; 153 struct adcxx1c_model *model; 154 int err; 155 156 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) 157 return -EOPNOTSUPP; 158 159 if (ACPI_COMPANION(&client->dev)) { 160 const struct acpi_device_id *ad_id; 161 162 ad_id = acpi_match_device(client->dev.driver->acpi_match_table, 163 &client->dev); 164 if (!ad_id) 165 return -ENODEV; 166 model = &adcxx1c_models[ad_id->driver_data]; 167 } else { 168 model = &adcxx1c_models[id->driver_data]; 169 } 170 171 iio = devm_iio_device_alloc(&client->dev, sizeof(*adc)); 172 if (!iio) 173 return -ENOMEM; 174 175 adc = iio_priv(iio); 176 adc->i2c = client; 177 adc->bits = model->bits; 178 179 adc->ref = devm_regulator_get(&client->dev, "vref"); 180 if (IS_ERR(adc->ref)) 181 return PTR_ERR(adc->ref); 182 183 err = regulator_enable(adc->ref); 184 if (err < 0) 185 return err; 186 187 iio->dev.parent = &client->dev; 188 iio->dev.of_node = client->dev.of_node; 189 iio->name = dev_name(&client->dev); 190 iio->modes = INDIO_DIRECT_MODE; 191 iio->info = &adc081c_info; 192 193 iio->channels = model->channels; 194 iio->num_channels = ADC081C_NUM_CHANNELS; 195 196 err = iio_triggered_buffer_setup(iio, NULL, adc081c_trigger_handler, NULL); 197 if (err < 0) { 198 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 199 goto err_regulator_disable; 200 } 201 202 err = iio_device_register(iio); 203 if (err < 0) 204 goto err_buffer_cleanup; 205 206 i2c_set_clientdata(client, iio); 207 208 return 0; 209 210 err_buffer_cleanup: 211 iio_triggered_buffer_cleanup(iio); 212 err_regulator_disable: 213 regulator_disable(adc->ref); 214 215 return err; 216 } 217 218 static int adc081c_remove(struct i2c_client *client) 219 { 220 struct iio_dev *iio = i2c_get_clientdata(client); 221 struct adc081c *adc = iio_priv(iio); 222 223 iio_device_unregister(iio); 224 iio_triggered_buffer_cleanup(iio); 225 regulator_disable(adc->ref); 226 227 return 0; 228 } 229 230 static const struct i2c_device_id adc081c_id[] = { 231 { "adc081c", ADC081C }, 232 { "adc101c", ADC101C }, 233 { "adc121c", ADC121C }, 234 { } 235 }; 236 MODULE_DEVICE_TABLE(i2c, adc081c_id); 237 238 #ifdef CONFIG_OF 239 static const struct of_device_id adc081c_of_match[] = { 240 { .compatible = "ti,adc081c" }, 241 { .compatible = "ti,adc101c" }, 242 { .compatible = "ti,adc121c" }, 243 { } 244 }; 245 MODULE_DEVICE_TABLE(of, adc081c_of_match); 246 #endif 247 248 #ifdef CONFIG_ACPI 249 static const struct acpi_device_id adc081c_acpi_match[] = { 250 { "ADC081C", ADC081C }, 251 { "ADC101C", ADC101C }, 252 { "ADC121C", ADC121C }, 253 { } 254 }; 255 MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match); 256 #endif 257 258 static struct i2c_driver adc081c_driver = { 259 .driver = { 260 .name = "adc081c", 261 .of_match_table = of_match_ptr(adc081c_of_match), 262 .acpi_match_table = ACPI_PTR(adc081c_acpi_match), 263 }, 264 .probe = adc081c_probe, 265 .remove = adc081c_remove, 266 .id_table = adc081c_id, 267 }; 268 module_i2c_driver(adc081c_driver); 269 270 MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); 271 MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver"); 272 MODULE_LICENSE("GPL v2"); 273