1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Analog Devices AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver 4 * TI ADC081S/ADC101S/ADC121S 8/10/12-bit SPI ADC driver 5 * 6 * Copyright 2010 Analog Devices Inc. 7 */ 8 9 #include <linux/device.h> 10 #include <linux/kernel.h> 11 #include <linux/slab.h> 12 #include <linux/sysfs.h> 13 #include <linux/spi/spi.h> 14 #include <linux/regulator/consumer.h> 15 #include <linux/err.h> 16 #include <linux/module.h> 17 #include <linux/bitops.h> 18 19 #include <linux/iio/iio.h> 20 #include <linux/iio/sysfs.h> 21 #include <linux/iio/buffer.h> 22 #include <linux/iio/trigger_consumer.h> 23 #include <linux/iio/triggered_buffer.h> 24 25 struct ad7476_state; 26 27 struct ad7476_chip_info { 28 unsigned int int_vref_uv; 29 struct iio_chan_spec channel[2]; 30 void (*reset)(struct ad7476_state *); 31 }; 32 33 struct ad7476_state { 34 struct spi_device *spi; 35 const struct ad7476_chip_info *chip_info; 36 struct regulator *reg; 37 struct spi_transfer xfer; 38 struct spi_message msg; 39 /* 40 * DMA (thus cache coherency maintenance) requires the 41 * transfer buffers to live in their own cache lines. 42 * Make the buffer large enough for one 16 bit sample and one 64 bit 43 * aligned 64 bit timestamp. 44 */ 45 unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)] 46 ____cacheline_aligned; 47 }; 48 49 enum ad7476_supported_device_ids { 50 ID_AD7091R, 51 ID_AD7276, 52 ID_AD7277, 53 ID_AD7278, 54 ID_AD7466, 55 ID_AD7467, 56 ID_AD7468, 57 ID_AD7495, 58 ID_AD7940, 59 ID_ADC081S, 60 ID_ADC101S, 61 ID_ADC121S, 62 }; 63 64 static irqreturn_t ad7476_trigger_handler(int irq, void *p) 65 { 66 struct iio_poll_func *pf = p; 67 struct iio_dev *indio_dev = pf->indio_dev; 68 struct ad7476_state *st = iio_priv(indio_dev); 69 int b_sent; 70 71 b_sent = spi_sync(st->spi, &st->msg); 72 if (b_sent < 0) 73 goto done; 74 75 iio_push_to_buffers_with_timestamp(indio_dev, st->data, 76 iio_get_time_ns(indio_dev)); 77 done: 78 iio_trigger_notify_done(indio_dev->trig); 79 80 return IRQ_HANDLED; 81 } 82 83 static void ad7091_reset(struct ad7476_state *st) 84 { 85 /* Any transfers with 8 scl cycles will reset the device */ 86 spi_read(st->spi, st->data, 1); 87 } 88 89 static int ad7476_scan_direct(struct ad7476_state *st) 90 { 91 int ret; 92 93 ret = spi_sync(st->spi, &st->msg); 94 if (ret) 95 return ret; 96 97 return be16_to_cpup((__be16 *)st->data); 98 } 99 100 static int ad7476_read_raw(struct iio_dev *indio_dev, 101 struct iio_chan_spec const *chan, 102 int *val, 103 int *val2, 104 long m) 105 { 106 int ret; 107 struct ad7476_state *st = iio_priv(indio_dev); 108 int scale_uv; 109 110 switch (m) { 111 case IIO_CHAN_INFO_RAW: 112 ret = iio_device_claim_direct_mode(indio_dev); 113 if (ret) 114 return ret; 115 ret = ad7476_scan_direct(st); 116 iio_device_release_direct_mode(indio_dev); 117 118 if (ret < 0) 119 return ret; 120 *val = (ret >> st->chip_info->channel[0].scan_type.shift) & 121 GENMASK(st->chip_info->channel[0].scan_type.realbits - 1, 0); 122 return IIO_VAL_INT; 123 case IIO_CHAN_INFO_SCALE: 124 if (!st->chip_info->int_vref_uv) { 125 scale_uv = regulator_get_voltage(st->reg); 126 if (scale_uv < 0) 127 return scale_uv; 128 } else { 129 scale_uv = st->chip_info->int_vref_uv; 130 } 131 *val = scale_uv / 1000; 132 *val2 = chan->scan_type.realbits; 133 return IIO_VAL_FRACTIONAL_LOG2; 134 } 135 return -EINVAL; 136 } 137 138 #define _AD7476_CHAN(bits, _shift, _info_mask_sep) \ 139 { \ 140 .type = IIO_VOLTAGE, \ 141 .indexed = 1, \ 142 .info_mask_separate = _info_mask_sep, \ 143 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 144 .scan_type = { \ 145 .sign = 'u', \ 146 .realbits = (bits), \ 147 .storagebits = 16, \ 148 .shift = (_shift), \ 149 .endianness = IIO_BE, \ 150 }, \ 151 } 152 153 #define ADC081S_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \ 154 BIT(IIO_CHAN_INFO_RAW)) 155 #define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \ 156 BIT(IIO_CHAN_INFO_RAW)) 157 #define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \ 158 BIT(IIO_CHAN_INFO_RAW)) 159 #define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0) 160 161 static const struct ad7476_chip_info ad7476_chip_info_tbl[] = { 162 [ID_AD7091R] = { 163 .channel[0] = AD7091R_CHAN(12), 164 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 165 .reset = ad7091_reset, 166 }, 167 [ID_AD7276] = { 168 .channel[0] = AD7940_CHAN(12), 169 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 170 }, 171 [ID_AD7277] = { 172 .channel[0] = AD7940_CHAN(10), 173 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 174 }, 175 [ID_AD7278] = { 176 .channel[0] = AD7940_CHAN(8), 177 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 178 }, 179 [ID_AD7466] = { 180 .channel[0] = AD7476_CHAN(12), 181 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 182 }, 183 [ID_AD7467] = { 184 .channel[0] = AD7476_CHAN(10), 185 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 186 }, 187 [ID_AD7468] = { 188 .channel[0] = AD7476_CHAN(8), 189 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 190 }, 191 [ID_AD7495] = { 192 .channel[0] = AD7476_CHAN(12), 193 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 194 .int_vref_uv = 2500000, 195 }, 196 [ID_AD7940] = { 197 .channel[0] = AD7940_CHAN(14), 198 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 199 }, 200 [ID_ADC081S] = { 201 .channel[0] = ADC081S_CHAN(8), 202 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 203 }, 204 [ID_ADC101S] = { 205 .channel[0] = ADC081S_CHAN(10), 206 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 207 }, 208 [ID_ADC121S] = { 209 .channel[0] = ADC081S_CHAN(12), 210 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 211 }, 212 }; 213 214 static const struct iio_info ad7476_info = { 215 .read_raw = &ad7476_read_raw, 216 }; 217 218 static int ad7476_probe(struct spi_device *spi) 219 { 220 struct ad7476_state *st; 221 struct iio_dev *indio_dev; 222 int ret; 223 224 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 225 if (!indio_dev) 226 return -ENOMEM; 227 228 st = iio_priv(indio_dev); 229 st->chip_info = 230 &ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data]; 231 232 st->reg = devm_regulator_get(&spi->dev, "vcc"); 233 if (IS_ERR(st->reg)) 234 return PTR_ERR(st->reg); 235 236 ret = regulator_enable(st->reg); 237 if (ret) 238 return ret; 239 240 spi_set_drvdata(spi, indio_dev); 241 242 st->spi = spi; 243 244 /* Establish that the iio_dev is a child of the spi device */ 245 indio_dev->dev.parent = &spi->dev; 246 indio_dev->dev.of_node = spi->dev.of_node; 247 indio_dev->name = spi_get_device_id(spi)->name; 248 indio_dev->modes = INDIO_DIRECT_MODE; 249 indio_dev->channels = st->chip_info->channel; 250 indio_dev->num_channels = 2; 251 indio_dev->info = &ad7476_info; 252 /* Setup default message */ 253 254 st->xfer.rx_buf = &st->data; 255 st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8; 256 257 spi_message_init(&st->msg); 258 spi_message_add_tail(&st->xfer, &st->msg); 259 260 ret = iio_triggered_buffer_setup(indio_dev, NULL, 261 &ad7476_trigger_handler, NULL); 262 if (ret) 263 goto error_disable_reg; 264 265 if (st->chip_info->reset) 266 st->chip_info->reset(st); 267 268 ret = iio_device_register(indio_dev); 269 if (ret) 270 goto error_ring_unregister; 271 return 0; 272 273 error_ring_unregister: 274 iio_triggered_buffer_cleanup(indio_dev); 275 error_disable_reg: 276 regulator_disable(st->reg); 277 278 return ret; 279 } 280 281 static int ad7476_remove(struct spi_device *spi) 282 { 283 struct iio_dev *indio_dev = spi_get_drvdata(spi); 284 struct ad7476_state *st = iio_priv(indio_dev); 285 286 iio_device_unregister(indio_dev); 287 iio_triggered_buffer_cleanup(indio_dev); 288 regulator_disable(st->reg); 289 290 return 0; 291 } 292 293 static const struct spi_device_id ad7476_id[] = { 294 {"ad7091r", ID_AD7091R}, 295 {"ad7273", ID_AD7277}, 296 {"ad7274", ID_AD7276}, 297 {"ad7276", ID_AD7276}, 298 {"ad7277", ID_AD7277}, 299 {"ad7278", ID_AD7278}, 300 {"ad7466", ID_AD7466}, 301 {"ad7467", ID_AD7467}, 302 {"ad7468", ID_AD7468}, 303 {"ad7475", ID_AD7466}, 304 {"ad7476", ID_AD7466}, 305 {"ad7476a", ID_AD7466}, 306 {"ad7477", ID_AD7467}, 307 {"ad7477a", ID_AD7467}, 308 {"ad7478", ID_AD7468}, 309 {"ad7478a", ID_AD7468}, 310 {"ad7495", ID_AD7495}, 311 {"ad7910", ID_AD7467}, 312 {"ad7920", ID_AD7466}, 313 {"ad7940", ID_AD7940}, 314 {"adc081s", ID_ADC081S}, 315 {"adc101s", ID_ADC101S}, 316 {"adc121s", ID_ADC121S}, 317 {} 318 }; 319 MODULE_DEVICE_TABLE(spi, ad7476_id); 320 321 static struct spi_driver ad7476_driver = { 322 .driver = { 323 .name = "ad7476", 324 }, 325 .probe = ad7476_probe, 326 .remove = ad7476_remove, 327 .id_table = ad7476_id, 328 }; 329 module_spi_driver(ad7476_driver); 330 331 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 332 MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs"); 333 MODULE_LICENSE("GPL v2"); 334