1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter 4 * 5 * Copyright 2016 Qtechnology A/S 6 * 2016 Ricardo Ribalda <ricardo.ribalda@gmail.com> 7 */ 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/spi/spi.h> 11 #include <linux/bitops.h> 12 #include <linux/iio/iio.h> 13 #include <linux/iio/sysfs.h> 14 #include <linux/regulator/consumer.h> 15 #include <linux/platform_data/ad5761.h> 16 17 #define AD5761_ADDR(addr) ((addr & 0xf) << 16) 18 #define AD5761_ADDR_NOOP 0x0 19 #define AD5761_ADDR_DAC_WRITE 0x3 20 #define AD5761_ADDR_CTRL_WRITE_REG 0x4 21 #define AD5761_ADDR_SW_DATA_RESET 0x7 22 #define AD5761_ADDR_DAC_READ 0xb 23 #define AD5761_ADDR_CTRL_READ_REG 0xc 24 #define AD5761_ADDR_SW_FULL_RESET 0xf 25 26 #define AD5761_CTRL_USE_INTVREF BIT(5) 27 #define AD5761_CTRL_ETS BIT(6) 28 29 /** 30 * struct ad5761_chip_info - chip specific information 31 * @int_vref: Value of the internal reference voltage in mV - 0 if external 32 * reference voltage is used 33 * @channel: channel specification 34 */ 35 36 struct ad5761_chip_info { 37 unsigned long int_vref; 38 const struct iio_chan_spec channel; 39 }; 40 41 struct ad5761_range_params { 42 int m; 43 int c; 44 }; 45 46 enum ad5761_supported_device_ids { 47 ID_AD5721, 48 ID_AD5721R, 49 ID_AD5761, 50 ID_AD5761R, 51 }; 52 53 /** 54 * struct ad5761_state - driver instance specific data 55 * @spi: spi_device 56 * @vref_reg: reference voltage regulator 57 * @use_intref: true when the internal voltage reference is used 58 * @vref: actual voltage reference in mVolts 59 * @range: output range mode used 60 * @data: cache aligned spi buffer 61 */ 62 struct ad5761_state { 63 struct spi_device *spi; 64 struct regulator *vref_reg; 65 66 bool use_intref; 67 int vref; 68 enum ad5761_voltage_range range; 69 70 /* 71 * DMA (thus cache coherency maintenance) requires the 72 * transfer buffers to live in their own cache lines. 73 */ 74 union { 75 __be32 d32; 76 u8 d8[4]; 77 } data[3] ____cacheline_aligned; 78 }; 79 80 static const struct ad5761_range_params ad5761_range_params[] = { 81 [AD5761_VOLTAGE_RANGE_M10V_10V] = { 82 .m = 80, 83 .c = 40, 84 }, 85 [AD5761_VOLTAGE_RANGE_0V_10V] = { 86 .m = 40, 87 .c = 0, 88 }, 89 [AD5761_VOLTAGE_RANGE_M5V_5V] = { 90 .m = 40, 91 .c = 20, 92 }, 93 [AD5761_VOLTAGE_RANGE_0V_5V] = { 94 .m = 20, 95 .c = 0, 96 }, 97 [AD5761_VOLTAGE_RANGE_M2V5_7V5] = { 98 .m = 40, 99 .c = 10, 100 }, 101 [AD5761_VOLTAGE_RANGE_M3V_3V] = { 102 .m = 24, 103 .c = 12, 104 }, 105 [AD5761_VOLTAGE_RANGE_0V_16V] = { 106 .m = 64, 107 .c = 0, 108 }, 109 [AD5761_VOLTAGE_RANGE_0V_20V] = { 110 .m = 80, 111 .c = 0, 112 }, 113 }; 114 115 static int _ad5761_spi_write(struct ad5761_state *st, u8 addr, u16 val) 116 { 117 st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr) | val); 118 119 return spi_write(st->spi, &st->data[0].d8[1], 3); 120 } 121 122 static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val) 123 { 124 struct ad5761_state *st = iio_priv(indio_dev); 125 int ret; 126 127 mutex_lock(&indio_dev->mlock); 128 ret = _ad5761_spi_write(st, addr, val); 129 mutex_unlock(&indio_dev->mlock); 130 131 return ret; 132 } 133 134 static int _ad5761_spi_read(struct ad5761_state *st, u8 addr, u16 *val) 135 { 136 int ret; 137 struct spi_transfer xfers[] = { 138 { 139 .tx_buf = &st->data[0].d8[1], 140 .bits_per_word = 8, 141 .len = 3, 142 .cs_change = true, 143 }, { 144 .tx_buf = &st->data[1].d8[1], 145 .rx_buf = &st->data[2].d8[1], 146 .bits_per_word = 8, 147 .len = 3, 148 }, 149 }; 150 151 st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr)); 152 st->data[1].d32 = cpu_to_be32(AD5761_ADDR(AD5761_ADDR_NOOP)); 153 154 ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers)); 155 156 *val = be32_to_cpu(st->data[2].d32); 157 158 return ret; 159 } 160 161 static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val) 162 { 163 struct ad5761_state *st = iio_priv(indio_dev); 164 int ret; 165 166 mutex_lock(&indio_dev->mlock); 167 ret = _ad5761_spi_read(st, addr, val); 168 mutex_unlock(&indio_dev->mlock); 169 170 return ret; 171 } 172 173 static int ad5761_spi_set_range(struct ad5761_state *st, 174 enum ad5761_voltage_range range) 175 { 176 u16 aux; 177 int ret; 178 179 aux = (range & 0x7) | AD5761_CTRL_ETS; 180 181 if (st->use_intref) 182 aux |= AD5761_CTRL_USE_INTVREF; 183 184 ret = _ad5761_spi_write(st, AD5761_ADDR_SW_FULL_RESET, 0); 185 if (ret) 186 return ret; 187 188 ret = _ad5761_spi_write(st, AD5761_ADDR_CTRL_WRITE_REG, aux); 189 if (ret) 190 return ret; 191 192 st->range = range; 193 194 return 0; 195 } 196 197 static int ad5761_read_raw(struct iio_dev *indio_dev, 198 struct iio_chan_spec const *chan, 199 int *val, 200 int *val2, 201 long mask) 202 { 203 struct ad5761_state *st; 204 int ret; 205 u16 aux; 206 207 switch (mask) { 208 case IIO_CHAN_INFO_RAW: 209 ret = ad5761_spi_read(indio_dev, AD5761_ADDR_DAC_READ, &aux); 210 if (ret) 211 return ret; 212 *val = aux >> chan->scan_type.shift; 213 return IIO_VAL_INT; 214 case IIO_CHAN_INFO_SCALE: 215 st = iio_priv(indio_dev); 216 *val = st->vref * ad5761_range_params[st->range].m; 217 *val /= 10; 218 *val2 = chan->scan_type.realbits; 219 return IIO_VAL_FRACTIONAL_LOG2; 220 case IIO_CHAN_INFO_OFFSET: 221 st = iio_priv(indio_dev); 222 *val = -(1 << chan->scan_type.realbits); 223 *val *= ad5761_range_params[st->range].c; 224 *val /= ad5761_range_params[st->range].m; 225 return IIO_VAL_INT; 226 default: 227 return -EINVAL; 228 } 229 } 230 231 static int ad5761_write_raw(struct iio_dev *indio_dev, 232 struct iio_chan_spec const *chan, 233 int val, 234 int val2, 235 long mask) 236 { 237 u16 aux; 238 239 if (mask != IIO_CHAN_INFO_RAW) 240 return -EINVAL; 241 242 if (val2 || (val << chan->scan_type.shift) > 0xffff || val < 0) 243 return -EINVAL; 244 245 aux = val << chan->scan_type.shift; 246 247 return ad5761_spi_write(indio_dev, AD5761_ADDR_DAC_WRITE, aux); 248 } 249 250 static const struct iio_info ad5761_info = { 251 .read_raw = &ad5761_read_raw, 252 .write_raw = &ad5761_write_raw, 253 }; 254 255 #define AD5761_CHAN(_bits) { \ 256 .type = IIO_VOLTAGE, \ 257 .output = 1, \ 258 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 259 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ 260 BIT(IIO_CHAN_INFO_OFFSET), \ 261 .scan_type = { \ 262 .sign = 'u', \ 263 .realbits = (_bits), \ 264 .storagebits = 16, \ 265 .shift = 16 - (_bits), \ 266 }, \ 267 } 268 269 static const struct ad5761_chip_info ad5761_chip_infos[] = { 270 [ID_AD5721] = { 271 .int_vref = 0, 272 .channel = AD5761_CHAN(12), 273 }, 274 [ID_AD5721R] = { 275 .int_vref = 2500, 276 .channel = AD5761_CHAN(12), 277 }, 278 [ID_AD5761] = { 279 .int_vref = 0, 280 .channel = AD5761_CHAN(16), 281 }, 282 [ID_AD5761R] = { 283 .int_vref = 2500, 284 .channel = AD5761_CHAN(16), 285 }, 286 }; 287 288 static int ad5761_get_vref(struct ad5761_state *st, 289 const struct ad5761_chip_info *chip_info) 290 { 291 int ret; 292 293 st->vref_reg = devm_regulator_get_optional(&st->spi->dev, "vref"); 294 if (PTR_ERR(st->vref_reg) == -ENODEV) { 295 /* Use Internal regulator */ 296 if (!chip_info->int_vref) { 297 dev_err(&st->spi->dev, 298 "Voltage reference not found\n"); 299 return -EIO; 300 } 301 302 st->use_intref = true; 303 st->vref = chip_info->int_vref; 304 return 0; 305 } 306 307 if (IS_ERR(st->vref_reg)) { 308 dev_err(&st->spi->dev, 309 "Error getting voltage reference regulator\n"); 310 return PTR_ERR(st->vref_reg); 311 } 312 313 ret = regulator_enable(st->vref_reg); 314 if (ret) { 315 dev_err(&st->spi->dev, 316 "Failed to enable voltage reference\n"); 317 return ret; 318 } 319 320 ret = regulator_get_voltage(st->vref_reg); 321 if (ret < 0) { 322 dev_err(&st->spi->dev, 323 "Failed to get voltage reference value\n"); 324 goto disable_regulator_vref; 325 } 326 327 if (ret < 2000000 || ret > 3000000) { 328 dev_warn(&st->spi->dev, 329 "Invalid external voltage ref. value %d uV\n", ret); 330 ret = -EIO; 331 goto disable_regulator_vref; 332 } 333 334 st->vref = ret / 1000; 335 st->use_intref = false; 336 337 return 0; 338 339 disable_regulator_vref: 340 regulator_disable(st->vref_reg); 341 st->vref_reg = NULL; 342 return ret; 343 } 344 345 static int ad5761_probe(struct spi_device *spi) 346 { 347 struct iio_dev *iio_dev; 348 struct ad5761_state *st; 349 int ret; 350 const struct ad5761_chip_info *chip_info = 351 &ad5761_chip_infos[spi_get_device_id(spi)->driver_data]; 352 enum ad5761_voltage_range voltage_range = AD5761_VOLTAGE_RANGE_0V_5V; 353 struct ad5761_platform_data *pdata = dev_get_platdata(&spi->dev); 354 355 iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 356 if (!iio_dev) 357 return -ENOMEM; 358 359 st = iio_priv(iio_dev); 360 361 st->spi = spi; 362 spi_set_drvdata(spi, iio_dev); 363 364 ret = ad5761_get_vref(st, chip_info); 365 if (ret) 366 return ret; 367 368 if (pdata) 369 voltage_range = pdata->voltage_range; 370 371 ret = ad5761_spi_set_range(st, voltage_range); 372 if (ret) 373 goto disable_regulator_err; 374 375 iio_dev->dev.parent = &spi->dev; 376 iio_dev->info = &ad5761_info; 377 iio_dev->modes = INDIO_DIRECT_MODE; 378 iio_dev->channels = &chip_info->channel; 379 iio_dev->num_channels = 1; 380 iio_dev->name = spi_get_device_id(st->spi)->name; 381 ret = iio_device_register(iio_dev); 382 if (ret) 383 goto disable_regulator_err; 384 385 return 0; 386 387 disable_regulator_err: 388 if (!IS_ERR_OR_NULL(st->vref_reg)) 389 regulator_disable(st->vref_reg); 390 391 return ret; 392 } 393 394 static int ad5761_remove(struct spi_device *spi) 395 { 396 struct iio_dev *iio_dev = spi_get_drvdata(spi); 397 struct ad5761_state *st = iio_priv(iio_dev); 398 399 iio_device_unregister(iio_dev); 400 401 if (!IS_ERR_OR_NULL(st->vref_reg)) 402 regulator_disable(st->vref_reg); 403 404 return 0; 405 } 406 407 static const struct spi_device_id ad5761_id[] = { 408 {"ad5721", ID_AD5721}, 409 {"ad5721r", ID_AD5721R}, 410 {"ad5761", ID_AD5761}, 411 {"ad5761r", ID_AD5761R}, 412 {} 413 }; 414 MODULE_DEVICE_TABLE(spi, ad5761_id); 415 416 static struct spi_driver ad5761_driver = { 417 .driver = { 418 .name = "ad5761", 419 }, 420 .probe = ad5761_probe, 421 .remove = ad5761_remove, 422 .id_table = ad5761_id, 423 }; 424 module_spi_driver(ad5761_driver); 425 426 MODULE_AUTHOR("Ricardo Ribalda <ricardo.ribalda@gmail.com>"); 427 MODULE_DESCRIPTION("Analog Devices AD5721, AD5721R, AD5761, AD5761R driver"); 428 MODULE_LICENSE("GPL v2"); 429