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 23 #include <linux/iio/iio.h> 24 #include <linux/iio/buffer.h> 25 #include <linux/iio/trigger_consumer.h> 26 #include <linux/iio/triggered_buffer.h> 27 #include <linux/regulator/consumer.h> 28 29 struct adc081c { 30 struct i2c_client *i2c; 31 struct regulator *ref; 32 33 /* 8, 10 or 12 */ 34 int bits; 35 36 /* Ensure natural alignment of buffer elements */ 37 struct { 38 u16 channel; 39 s64 ts __aligned(8); 40 } scan; 41 }; 42 43 #define REG_CONV_RES 0x00 44 45 static int adc081c_read_raw(struct iio_dev *iio, 46 struct iio_chan_spec const *channel, int *value, 47 int *shift, long mask) 48 { 49 struct adc081c *adc = iio_priv(iio); 50 int err; 51 52 switch (mask) { 53 case IIO_CHAN_INFO_RAW: 54 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES); 55 if (err < 0) 56 return err; 57 58 *value = (err & 0xFFF) >> (12 - adc->bits); 59 return IIO_VAL_INT; 60 61 case IIO_CHAN_INFO_SCALE: 62 err = regulator_get_voltage(adc->ref); 63 if (err < 0) 64 return err; 65 66 *value = err / 1000; 67 *shift = adc->bits; 68 69 return IIO_VAL_FRACTIONAL_LOG2; 70 71 default: 72 break; 73 } 74 75 return -EINVAL; 76 } 77 78 #define ADCxx1C_CHAN(_bits) { \ 79 .type = IIO_VOLTAGE, \ 80 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 81 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 82 .scan_type = { \ 83 .sign = 'u', \ 84 .realbits = (_bits), \ 85 .storagebits = 16, \ 86 .shift = 12 - (_bits), \ 87 .endianness = IIO_CPU, \ 88 }, \ 89 } 90 91 #define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \ 92 static const struct iio_chan_spec _name ## _channels[] = { \ 93 ADCxx1C_CHAN((_bits)), \ 94 IIO_CHAN_SOFT_TIMESTAMP(1), \ 95 }; \ 96 97 #define ADC081C_NUM_CHANNELS 2 98 99 struct adcxx1c_model { 100 const struct iio_chan_spec* channels; 101 int bits; 102 }; 103 104 #define ADCxx1C_MODEL(_name, _bits) \ 105 { \ 106 .channels = _name ## _channels, \ 107 .bits = (_bits), \ 108 } 109 110 DEFINE_ADCxx1C_CHANNELS(adc081c, 8); 111 DEFINE_ADCxx1C_CHANNELS(adc101c, 10); 112 DEFINE_ADCxx1C_CHANNELS(adc121c, 12); 113 114 /* Model ids are indexes in _models array */ 115 enum adcxx1c_model_id { 116 ADC081C = 0, 117 ADC101C = 1, 118 ADC121C = 2, 119 }; 120 121 static struct adcxx1c_model adcxx1c_models[] = { 122 ADCxx1C_MODEL(adc081c, 8), 123 ADCxx1C_MODEL(adc101c, 10), 124 ADCxx1C_MODEL(adc121c, 12), 125 }; 126 127 static const struct iio_info adc081c_info = { 128 .read_raw = adc081c_read_raw, 129 }; 130 131 static irqreturn_t adc081c_trigger_handler(int irq, void *p) 132 { 133 struct iio_poll_func *pf = p; 134 struct iio_dev *indio_dev = pf->indio_dev; 135 struct adc081c *data = iio_priv(indio_dev); 136 int ret; 137 138 ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES); 139 if (ret < 0) 140 goto out; 141 data->scan.channel = ret; 142 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 143 iio_get_time_ns(indio_dev)); 144 out: 145 iio_trigger_notify_done(indio_dev->trig); 146 return IRQ_HANDLED; 147 } 148 149 static void adc081c_reg_disable(void *reg) 150 { 151 regulator_disable(reg); 152 } 153 154 static int adc081c_probe(struct i2c_client *client, 155 const struct i2c_device_id *id) 156 { 157 struct iio_dev *iio; 158 struct adc081c *adc; 159 struct adcxx1c_model *model; 160 int err; 161 162 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) 163 return -EOPNOTSUPP; 164 165 model = &adcxx1c_models[id->driver_data]; 166 167 iio = devm_iio_device_alloc(&client->dev, sizeof(*adc)); 168 if (!iio) 169 return -ENOMEM; 170 171 adc = iio_priv(iio); 172 adc->i2c = client; 173 adc->bits = model->bits; 174 175 adc->ref = devm_regulator_get(&client->dev, "vref"); 176 if (IS_ERR(adc->ref)) 177 return PTR_ERR(adc->ref); 178 179 err = regulator_enable(adc->ref); 180 if (err < 0) 181 return err; 182 183 err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable, 184 adc->ref); 185 if (err) 186 return err; 187 188 iio->name = dev_name(&client->dev); 189 iio->modes = INDIO_DIRECT_MODE; 190 iio->info = &adc081c_info; 191 192 iio->channels = model->channels; 193 iio->num_channels = ADC081C_NUM_CHANNELS; 194 195 err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL, 196 adc081c_trigger_handler, NULL); 197 if (err < 0) { 198 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 199 return err; 200 } 201 202 return devm_iio_device_register(&client->dev, iio); 203 } 204 205 static const struct i2c_device_id adc081c_id[] = { 206 { "adc081c", ADC081C }, 207 { "adc101c", ADC101C }, 208 { "adc121c", ADC121C }, 209 { } 210 }; 211 MODULE_DEVICE_TABLE(i2c, adc081c_id); 212 213 static const struct of_device_id adc081c_of_match[] = { 214 { .compatible = "ti,adc081c" }, 215 { .compatible = "ti,adc101c" }, 216 { .compatible = "ti,adc121c" }, 217 { } 218 }; 219 MODULE_DEVICE_TABLE(of, adc081c_of_match); 220 221 static struct i2c_driver adc081c_driver = { 222 .driver = { 223 .name = "adc081c", 224 .of_match_table = adc081c_of_match, 225 }, 226 .probe = adc081c_probe, 227 .id_table = adc081c_id, 228 }; 229 module_i2c_driver(adc081c_driver); 230 231 MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); 232 MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver"); 233 MODULE_LICENSE("GPL v2"); 234