1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver 4 * 5 * Copyright (C) 2012 Avionic Design GmbH 6 * Copyright (C) 2016 Intel 7 * 8 * Datasheets: 9 * https://www.ti.com/lit/ds/symlink/adc081c021.pdf 10 * https://www.ti.com/lit/ds/symlink/adc101c021.pdf 11 * https://www.ti.com/lit/ds/symlink/adc121c021.pdf 12 * 13 * The devices have a very similar interface and differ mostly in the number of 14 * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2 15 * bits of value registers are reserved. 16 */ 17 18 #include <linux/err.h> 19 #include <linux/i2c.h> 20 #include <linux/module.h> 21 #include <linux/mod_devicetable.h> 22 #include <linux/acpi.h> 23 24 #include <linux/iio/iio.h> 25 #include <linux/iio/buffer.h> 26 #include <linux/iio/trigger_consumer.h> 27 #include <linux/iio/triggered_buffer.h> 28 #include <linux/regulator/consumer.h> 29 30 struct adc081c { 31 struct i2c_client *i2c; 32 struct regulator *ref; 33 34 /* 8, 10 or 12 */ 35 int bits; 36 }; 37 38 #define REG_CONV_RES 0x00 39 40 static int adc081c_read_raw(struct iio_dev *iio, 41 struct iio_chan_spec const *channel, int *value, 42 int *shift, long mask) 43 { 44 struct adc081c *adc = iio_priv(iio); 45 int err; 46 47 switch (mask) { 48 case IIO_CHAN_INFO_RAW: 49 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES); 50 if (err < 0) 51 return err; 52 53 *value = (err & 0xFFF) >> (12 - adc->bits); 54 return IIO_VAL_INT; 55 56 case IIO_CHAN_INFO_SCALE: 57 err = regulator_get_voltage(adc->ref); 58 if (err < 0) 59 return err; 60 61 *value = err / 1000; 62 *shift = adc->bits; 63 64 return IIO_VAL_FRACTIONAL_LOG2; 65 66 default: 67 break; 68 } 69 70 return -EINVAL; 71 } 72 73 #define ADCxx1C_CHAN(_bits) { \ 74 .type = IIO_VOLTAGE, \ 75 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 76 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 77 .scan_type = { \ 78 .sign = 'u', \ 79 .realbits = (_bits), \ 80 .storagebits = 16, \ 81 .shift = 12 - (_bits), \ 82 .endianness = IIO_CPU, \ 83 }, \ 84 } 85 86 #define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \ 87 static const struct iio_chan_spec _name ## _channels[] = { \ 88 ADCxx1C_CHAN((_bits)), \ 89 IIO_CHAN_SOFT_TIMESTAMP(1), \ 90 }; \ 91 92 #define ADC081C_NUM_CHANNELS 2 93 94 struct adcxx1c_model { 95 const struct iio_chan_spec* channels; 96 int bits; 97 }; 98 99 #define ADCxx1C_MODEL(_name, _bits) \ 100 { \ 101 .channels = _name ## _channels, \ 102 .bits = (_bits), \ 103 } 104 105 DEFINE_ADCxx1C_CHANNELS(adc081c, 8); 106 DEFINE_ADCxx1C_CHANNELS(adc101c, 10); 107 DEFINE_ADCxx1C_CHANNELS(adc121c, 12); 108 109 /* Model ids are indexes in _models array */ 110 enum adcxx1c_model_id { 111 ADC081C = 0, 112 ADC101C = 1, 113 ADC121C = 2, 114 }; 115 116 static struct adcxx1c_model adcxx1c_models[] = { 117 ADCxx1C_MODEL(adc081c, 8), 118 ADCxx1C_MODEL(adc101c, 10), 119 ADCxx1C_MODEL(adc121c, 12), 120 }; 121 122 static const struct iio_info adc081c_info = { 123 .read_raw = adc081c_read_raw, 124 }; 125 126 static irqreturn_t adc081c_trigger_handler(int irq, void *p) 127 { 128 struct iio_poll_func *pf = p; 129 struct iio_dev *indio_dev = pf->indio_dev; 130 struct adc081c *data = iio_priv(indio_dev); 131 u16 buf[8]; /* 2 bytes data + 6 bytes padding + 8 bytes timestamp */ 132 int ret; 133 134 ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES); 135 if (ret < 0) 136 goto out; 137 buf[0] = ret; 138 iio_push_to_buffers_with_timestamp(indio_dev, buf, 139 iio_get_time_ns(indio_dev)); 140 out: 141 iio_trigger_notify_done(indio_dev->trig); 142 return IRQ_HANDLED; 143 } 144 145 static int adc081c_probe(struct i2c_client *client, 146 const struct i2c_device_id *id) 147 { 148 struct iio_dev *iio; 149 struct adc081c *adc; 150 struct adcxx1c_model *model; 151 int err; 152 153 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) 154 return -EOPNOTSUPP; 155 156 if (ACPI_COMPANION(&client->dev)) { 157 const struct acpi_device_id *ad_id; 158 159 ad_id = acpi_match_device(client->dev.driver->acpi_match_table, 160 &client->dev); 161 if (!ad_id) 162 return -ENODEV; 163 model = &adcxx1c_models[ad_id->driver_data]; 164 } else { 165 model = &adcxx1c_models[id->driver_data]; 166 } 167 168 iio = devm_iio_device_alloc(&client->dev, sizeof(*adc)); 169 if (!iio) 170 return -ENOMEM; 171 172 adc = iio_priv(iio); 173 adc->i2c = client; 174 adc->bits = model->bits; 175 176 adc->ref = devm_regulator_get(&client->dev, "vref"); 177 if (IS_ERR(adc->ref)) 178 return PTR_ERR(adc->ref); 179 180 err = regulator_enable(adc->ref); 181 if (err < 0) 182 return err; 183 184 iio->name = dev_name(&client->dev); 185 iio->modes = INDIO_DIRECT_MODE; 186 iio->info = &adc081c_info; 187 188 iio->channels = model->channels; 189 iio->num_channels = ADC081C_NUM_CHANNELS; 190 191 err = iio_triggered_buffer_setup(iio, NULL, adc081c_trigger_handler, NULL); 192 if (err < 0) { 193 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 194 goto err_regulator_disable; 195 } 196 197 err = iio_device_register(iio); 198 if (err < 0) 199 goto err_buffer_cleanup; 200 201 i2c_set_clientdata(client, iio); 202 203 return 0; 204 205 err_buffer_cleanup: 206 iio_triggered_buffer_cleanup(iio); 207 err_regulator_disable: 208 regulator_disable(adc->ref); 209 210 return err; 211 } 212 213 static int adc081c_remove(struct i2c_client *client) 214 { 215 struct iio_dev *iio = i2c_get_clientdata(client); 216 struct adc081c *adc = iio_priv(iio); 217 218 iio_device_unregister(iio); 219 iio_triggered_buffer_cleanup(iio); 220 regulator_disable(adc->ref); 221 222 return 0; 223 } 224 225 static const struct i2c_device_id adc081c_id[] = { 226 { "adc081c", ADC081C }, 227 { "adc101c", ADC101C }, 228 { "adc121c", ADC121C }, 229 { } 230 }; 231 MODULE_DEVICE_TABLE(i2c, adc081c_id); 232 233 static const struct of_device_id adc081c_of_match[] = { 234 { .compatible = "ti,adc081c" }, 235 { .compatible = "ti,adc101c" }, 236 { .compatible = "ti,adc121c" }, 237 { } 238 }; 239 MODULE_DEVICE_TABLE(of, adc081c_of_match); 240 241 #ifdef CONFIG_ACPI 242 static const struct acpi_device_id adc081c_acpi_match[] = { 243 { "ADC081C", ADC081C }, 244 { "ADC101C", ADC101C }, 245 { "ADC121C", ADC121C }, 246 { } 247 }; 248 MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match); 249 #endif 250 251 static struct i2c_driver adc081c_driver = { 252 .driver = { 253 .name = "adc081c", 254 .of_match_table = adc081c_of_match, 255 .acpi_match_table = ACPI_PTR(adc081c_acpi_match), 256 }, 257 .probe = adc081c_probe, 258 .remove = adc081c_remove, 259 .id_table = adc081c_id, 260 }; 261 module_i2c_driver(adc081c_driver); 262 263 MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); 264 MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver"); 265 MODULE_LICENSE("GPL v2"); 266