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/property.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 /* Ensure natural alignment of buffer elements */ 38 struct { 39 u16 channel; 40 s64 ts __aligned(8); 41 } scan; 42 }; 43 44 #define REG_CONV_RES 0x00 45 46 static int adc081c_read_raw(struct iio_dev *iio, 47 struct iio_chan_spec const *channel, int *value, 48 int *shift, long mask) 49 { 50 struct adc081c *adc = iio_priv(iio); 51 int err; 52 53 switch (mask) { 54 case IIO_CHAN_INFO_RAW: 55 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES); 56 if (err < 0) 57 return err; 58 59 *value = (err & 0xFFF) >> (12 - adc->bits); 60 return IIO_VAL_INT; 61 62 case IIO_CHAN_INFO_SCALE: 63 err = regulator_get_voltage(adc->ref); 64 if (err < 0) 65 return err; 66 67 *value = err / 1000; 68 *shift = adc->bits; 69 70 return IIO_VAL_FRACTIONAL_LOG2; 71 72 default: 73 break; 74 } 75 76 return -EINVAL; 77 } 78 79 #define ADCxx1C_CHAN(_bits) { \ 80 .type = IIO_VOLTAGE, \ 81 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 82 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 83 .scan_type = { \ 84 .sign = 'u', \ 85 .realbits = (_bits), \ 86 .storagebits = 16, \ 87 .shift = 12 - (_bits), \ 88 .endianness = IIO_CPU, \ 89 }, \ 90 } 91 92 #define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \ 93 static const struct iio_chan_spec _name ## _channels[] = { \ 94 ADCxx1C_CHAN((_bits)), \ 95 IIO_CHAN_SOFT_TIMESTAMP(1), \ 96 }; \ 97 98 #define ADC081C_NUM_CHANNELS 2 99 100 struct adcxx1c_model { 101 const struct iio_chan_spec* channels; 102 int bits; 103 }; 104 105 #define ADCxx1C_MODEL(_name, _bits) \ 106 { \ 107 .channels = _name ## _channels, \ 108 .bits = (_bits), \ 109 } 110 111 DEFINE_ADCxx1C_CHANNELS(adc081c, 8); 112 DEFINE_ADCxx1C_CHANNELS(adc101c, 10); 113 DEFINE_ADCxx1C_CHANNELS(adc121c, 12); 114 115 /* Model ids are indexes in _models array */ 116 enum adcxx1c_model_id { 117 ADC081C = 0, 118 ADC101C = 1, 119 ADC121C = 2, 120 }; 121 122 static struct adcxx1c_model adcxx1c_models[] = { 123 ADCxx1C_MODEL(adc081c, 8), 124 ADCxx1C_MODEL(adc101c, 10), 125 ADCxx1C_MODEL(adc121c, 12), 126 }; 127 128 static const struct iio_info adc081c_info = { 129 .read_raw = adc081c_read_raw, 130 }; 131 132 static irqreturn_t adc081c_trigger_handler(int irq, void *p) 133 { 134 struct iio_poll_func *pf = p; 135 struct iio_dev *indio_dev = pf->indio_dev; 136 struct adc081c *data = iio_priv(indio_dev); 137 int ret; 138 139 ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES); 140 if (ret < 0) 141 goto out; 142 data->scan.channel = ret; 143 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 144 iio_get_time_ns(indio_dev)); 145 out: 146 iio_trigger_notify_done(indio_dev->trig); 147 return IRQ_HANDLED; 148 } 149 150 static void adc081c_reg_disable(void *reg) 151 { 152 regulator_disable(reg); 153 } 154 155 static int adc081c_probe(struct i2c_client *client) 156 { 157 const struct i2c_device_id *id = i2c_client_get_device_id(client); 158 struct iio_dev *iio; 159 struct adc081c *adc; 160 const struct adcxx1c_model *model; 161 int err; 162 163 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) 164 return -EOPNOTSUPP; 165 166 if (dev_fwnode(&client->dev)) 167 model = device_get_match_data(&client->dev); 168 else 169 model = &adcxx1c_models[id->driver_data]; 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 err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable, 188 adc->ref); 189 if (err) 190 return err; 191 192 iio->name = dev_name(&client->dev); 193 iio->modes = INDIO_DIRECT_MODE; 194 iio->info = &adc081c_info; 195 196 iio->channels = model->channels; 197 iio->num_channels = ADC081C_NUM_CHANNELS; 198 199 err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL, 200 adc081c_trigger_handler, NULL); 201 if (err < 0) { 202 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 203 return err; 204 } 205 206 return devm_iio_device_register(&client->dev, iio); 207 } 208 209 static const struct i2c_device_id adc081c_id[] = { 210 { "adc081c", ADC081C }, 211 { "adc101c", ADC101C }, 212 { "adc121c", ADC121C }, 213 { } 214 }; 215 MODULE_DEVICE_TABLE(i2c, adc081c_id); 216 217 static const struct acpi_device_id adc081c_acpi_match[] = { 218 /* Used on some AAEON boards */ 219 { "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] }, 220 { } 221 }; 222 MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match); 223 224 static const struct of_device_id adc081c_of_match[] = { 225 { .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] }, 226 { .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] }, 227 { .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] }, 228 { } 229 }; 230 MODULE_DEVICE_TABLE(of, adc081c_of_match); 231 232 static struct i2c_driver adc081c_driver = { 233 .driver = { 234 .name = "adc081c", 235 .of_match_table = adc081c_of_match, 236 .acpi_match_table = adc081c_acpi_match, 237 }, 238 .probe = adc081c_probe, 239 .id_table = adc081c_id, 240 }; 241 module_i2c_driver(adc081c_driver); 242 243 MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); 244 MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver"); 245 MODULE_LICENSE("GPL v2"); 246