1 /* 2 * AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog 3 * Converter 4 * 5 * Copyright 2011 Analog Devices Inc. 6 * 7 * Licensed under the GPL-2. 8 */ 9 10 #include <linux/interrupt.h> 11 #include <linux/fs.h> 12 #include <linux/device.h> 13 #include <linux/kernel.h> 14 #include <linux/spi/spi.h> 15 #include <linux/slab.h> 16 #include <linux/sysfs.h> 17 #include <linux/regulator/consumer.h> 18 #include <linux/module.h> 19 20 #include <linux/iio/iio.h> 21 #include <linux/iio/sysfs.h> 22 #include <linux/iio/dac/ad5791.h> 23 24 #define AD5791_RES_MASK(x) ((1 << (x)) - 1) 25 #define AD5791_DAC_MASK AD5791_RES_MASK(20) 26 #define AD5791_DAC_MSB (1 << 19) 27 28 #define AD5791_CMD_READ (1 << 23) 29 #define AD5791_CMD_WRITE (0 << 23) 30 #define AD5791_ADDR(addr) ((addr) << 20) 31 32 /* Registers */ 33 #define AD5791_ADDR_NOOP 0 34 #define AD5791_ADDR_DAC0 1 35 #define AD5791_ADDR_CTRL 2 36 #define AD5791_ADDR_CLRCODE 3 37 #define AD5791_ADDR_SW_CTRL 4 38 39 /* Control Register */ 40 #define AD5791_CTRL_RBUF (1 << 1) 41 #define AD5791_CTRL_OPGND (1 << 2) 42 #define AD5791_CTRL_DACTRI (1 << 3) 43 #define AD5791_CTRL_BIN2SC (1 << 4) 44 #define AD5791_CTRL_SDODIS (1 << 5) 45 #define AD5761_CTRL_LINCOMP(x) ((x) << 6) 46 47 #define AD5791_LINCOMP_0_10 0 48 #define AD5791_LINCOMP_10_12 1 49 #define AD5791_LINCOMP_12_16 2 50 #define AD5791_LINCOMP_16_19 3 51 #define AD5791_LINCOMP_19_20 12 52 53 #define AD5780_LINCOMP_0_10 0 54 #define AD5780_LINCOMP_10_20 12 55 56 /* Software Control Register */ 57 #define AD5791_SWCTRL_LDAC (1 << 0) 58 #define AD5791_SWCTRL_CLR (1 << 1) 59 #define AD5791_SWCTRL_RESET (1 << 2) 60 61 #define AD5791_DAC_PWRDN_6K 0 62 #define AD5791_DAC_PWRDN_3STATE 1 63 64 /** 65 * struct ad5791_chip_info - chip specific information 66 * @get_lin_comp: function pointer to the device specific function 67 */ 68 69 struct ad5791_chip_info { 70 int (*get_lin_comp) (unsigned int span); 71 }; 72 73 /** 74 * struct ad5791_state - driver instance specific data 75 * @us: spi_device 76 * @reg_vdd: positive supply regulator 77 * @reg_vss: negative supply regulator 78 * @chip_info: chip model specific constants 79 * @vref_mv: actual reference voltage used 80 * @vref_neg_mv: voltage of the negative supply 81 * @pwr_down_mode current power down mode 82 */ 83 84 struct ad5791_state { 85 struct spi_device *spi; 86 struct regulator *reg_vdd; 87 struct regulator *reg_vss; 88 const struct ad5791_chip_info *chip_info; 89 unsigned short vref_mv; 90 unsigned int vref_neg_mv; 91 unsigned ctrl; 92 unsigned pwr_down_mode; 93 bool pwr_down; 94 }; 95 96 /** 97 * ad5791_supported_device_ids: 98 */ 99 100 enum ad5791_supported_device_ids { 101 ID_AD5760, 102 ID_AD5780, 103 ID_AD5781, 104 ID_AD5791, 105 }; 106 107 static int ad5791_spi_write(struct spi_device *spi, u8 addr, u32 val) 108 { 109 union { 110 u32 d32; 111 u8 d8[4]; 112 } data; 113 114 data.d32 = cpu_to_be32(AD5791_CMD_WRITE | 115 AD5791_ADDR(addr) | 116 (val & AD5791_DAC_MASK)); 117 118 return spi_write(spi, &data.d8[1], 3); 119 } 120 121 static int ad5791_spi_read(struct spi_device *spi, u8 addr, u32 *val) 122 { 123 union { 124 u32 d32; 125 u8 d8[4]; 126 } data[3]; 127 int ret; 128 struct spi_transfer xfers[] = { 129 { 130 .tx_buf = &data[0].d8[1], 131 .bits_per_word = 8, 132 .len = 3, 133 .cs_change = 1, 134 }, { 135 .tx_buf = &data[1].d8[1], 136 .rx_buf = &data[2].d8[1], 137 .bits_per_word = 8, 138 .len = 3, 139 }, 140 }; 141 142 data[0].d32 = cpu_to_be32(AD5791_CMD_READ | 143 AD5791_ADDR(addr)); 144 data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP)); 145 146 ret = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers)); 147 148 *val = be32_to_cpu(data[2].d32); 149 150 return ret; 151 } 152 153 static const char * const ad5791_powerdown_modes[] = { 154 "6kohm_to_gnd", 155 "three_state", 156 }; 157 158 static int ad5791_get_powerdown_mode(struct iio_dev *indio_dev, 159 const struct iio_chan_spec *chan) 160 { 161 struct ad5791_state *st = iio_priv(indio_dev); 162 163 return st->pwr_down_mode; 164 } 165 166 static int ad5791_set_powerdown_mode(struct iio_dev *indio_dev, 167 const struct iio_chan_spec *chan, unsigned int mode) 168 { 169 struct ad5791_state *st = iio_priv(indio_dev); 170 171 st->pwr_down_mode = mode; 172 173 return 0; 174 } 175 176 static const struct iio_enum ad5791_powerdown_mode_enum = { 177 .items = ad5791_powerdown_modes, 178 .num_items = ARRAY_SIZE(ad5791_powerdown_modes), 179 .get = ad5791_get_powerdown_mode, 180 .set = ad5791_set_powerdown_mode, 181 }; 182 183 static ssize_t ad5791_read_dac_powerdown(struct iio_dev *indio_dev, 184 uintptr_t private, const struct iio_chan_spec *chan, char *buf) 185 { 186 struct ad5791_state *st = iio_priv(indio_dev); 187 188 return sprintf(buf, "%d\n", st->pwr_down); 189 } 190 191 static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev, 192 uintptr_t private, const struct iio_chan_spec *chan, const char *buf, 193 size_t len) 194 { 195 bool pwr_down; 196 int ret; 197 struct ad5791_state *st = iio_priv(indio_dev); 198 199 ret = strtobool(buf, &pwr_down); 200 if (ret) 201 return ret; 202 203 if (!pwr_down) { 204 st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI); 205 } else { 206 if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K) 207 st->ctrl |= AD5791_CTRL_OPGND; 208 else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE) 209 st->ctrl |= AD5791_CTRL_DACTRI; 210 } 211 st->pwr_down = pwr_down; 212 213 ret = ad5791_spi_write(st->spi, AD5791_ADDR_CTRL, st->ctrl); 214 215 return ret ? ret : len; 216 } 217 218 static int ad5791_get_lin_comp(unsigned int span) 219 { 220 if (span <= 10000) 221 return AD5791_LINCOMP_0_10; 222 else if (span <= 12000) 223 return AD5791_LINCOMP_10_12; 224 else if (span <= 16000) 225 return AD5791_LINCOMP_12_16; 226 else if (span <= 19000) 227 return AD5791_LINCOMP_16_19; 228 else 229 return AD5791_LINCOMP_19_20; 230 } 231 232 static int ad5780_get_lin_comp(unsigned int span) 233 { 234 if (span <= 10000) 235 return AD5780_LINCOMP_0_10; 236 else 237 return AD5780_LINCOMP_10_20; 238 } 239 static const struct ad5791_chip_info ad5791_chip_info_tbl[] = { 240 [ID_AD5760] = { 241 .get_lin_comp = ad5780_get_lin_comp, 242 }, 243 [ID_AD5780] = { 244 .get_lin_comp = ad5780_get_lin_comp, 245 }, 246 [ID_AD5781] = { 247 .get_lin_comp = ad5791_get_lin_comp, 248 }, 249 [ID_AD5791] = { 250 .get_lin_comp = ad5791_get_lin_comp, 251 }, 252 }; 253 254 static int ad5791_read_raw(struct iio_dev *indio_dev, 255 struct iio_chan_spec const *chan, 256 int *val, 257 int *val2, 258 long m) 259 { 260 struct ad5791_state *st = iio_priv(indio_dev); 261 u64 val64; 262 int ret; 263 264 switch (m) { 265 case IIO_CHAN_INFO_RAW: 266 ret = ad5791_spi_read(st->spi, chan->address, val); 267 if (ret) 268 return ret; 269 *val &= AD5791_DAC_MASK; 270 *val >>= chan->scan_type.shift; 271 return IIO_VAL_INT; 272 case IIO_CHAN_INFO_SCALE: 273 *val = st->vref_mv; 274 *val2 = (1 << chan->scan_type.realbits) - 1; 275 return IIO_VAL_FRACTIONAL; 276 case IIO_CHAN_INFO_OFFSET: 277 val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits); 278 do_div(val64, st->vref_mv); 279 *val = -val64; 280 return IIO_VAL_INT; 281 default: 282 return -EINVAL; 283 } 284 285 }; 286 287 static const struct iio_chan_spec_ext_info ad5791_ext_info[] = { 288 { 289 .name = "powerdown", 290 .shared = IIO_SHARED_BY_TYPE, 291 .read = ad5791_read_dac_powerdown, 292 .write = ad5791_write_dac_powerdown, 293 }, 294 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, 295 &ad5791_powerdown_mode_enum), 296 IIO_ENUM_AVAILABLE("powerdown_mode", &ad5791_powerdown_mode_enum), 297 { }, 298 }; 299 300 #define AD5791_CHAN(bits, shift) { \ 301 .type = IIO_VOLTAGE, \ 302 .output = 1, \ 303 .indexed = 1, \ 304 .address = AD5791_ADDR_DAC0, \ 305 .channel = 0, \ 306 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 307 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ 308 BIT(IIO_CHAN_INFO_OFFSET), \ 309 .scan_type = IIO_ST('u', bits, 24, shift), \ 310 .ext_info = ad5791_ext_info, \ 311 } 312 313 static const struct iio_chan_spec ad5791_channels[] = { 314 [ID_AD5760] = AD5791_CHAN(16, 4), 315 [ID_AD5780] = AD5791_CHAN(18, 2), 316 [ID_AD5781] = AD5791_CHAN(18, 2), 317 [ID_AD5791] = AD5791_CHAN(20, 0) 318 }; 319 320 static int ad5791_write_raw(struct iio_dev *indio_dev, 321 struct iio_chan_spec const *chan, 322 int val, 323 int val2, 324 long mask) 325 { 326 struct ad5791_state *st = iio_priv(indio_dev); 327 328 switch (mask) { 329 case IIO_CHAN_INFO_RAW: 330 val &= AD5791_RES_MASK(chan->scan_type.realbits); 331 val <<= chan->scan_type.shift; 332 333 return ad5791_spi_write(st->spi, chan->address, val); 334 335 default: 336 return -EINVAL; 337 } 338 } 339 340 static const struct iio_info ad5791_info = { 341 .read_raw = &ad5791_read_raw, 342 .write_raw = &ad5791_write_raw, 343 .driver_module = THIS_MODULE, 344 }; 345 346 static int ad5791_probe(struct spi_device *spi) 347 { 348 struct ad5791_platform_data *pdata = spi->dev.platform_data; 349 struct iio_dev *indio_dev; 350 struct ad5791_state *st; 351 int ret, pos_voltage_uv = 0, neg_voltage_uv = 0; 352 353 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 354 if (!indio_dev) 355 return -ENOMEM; 356 st = iio_priv(indio_dev); 357 st->reg_vdd = devm_regulator_get(&spi->dev, "vdd"); 358 if (!IS_ERR(st->reg_vdd)) { 359 ret = regulator_enable(st->reg_vdd); 360 if (ret) 361 return ret; 362 363 ret = regulator_get_voltage(st->reg_vdd); 364 if (ret < 0) 365 goto error_disable_reg_pos; 366 367 pos_voltage_uv = ret; 368 } 369 370 st->reg_vss = devm_regulator_get(&spi->dev, "vss"); 371 if (!IS_ERR(st->reg_vss)) { 372 ret = regulator_enable(st->reg_vss); 373 if (ret) 374 goto error_disable_reg_pos; 375 376 ret = regulator_get_voltage(st->reg_vss); 377 if (ret < 0) 378 goto error_disable_reg_neg; 379 380 neg_voltage_uv = ret; 381 } 382 383 st->pwr_down = true; 384 st->spi = spi; 385 386 if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) { 387 st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000; 388 st->vref_neg_mv = neg_voltage_uv / 1000; 389 } else if (pdata) { 390 st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv; 391 st->vref_neg_mv = pdata->vref_neg_mv; 392 } else { 393 dev_warn(&spi->dev, "reference voltage unspecified\n"); 394 } 395 396 ret = ad5791_spi_write(spi, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET); 397 if (ret) 398 goto error_disable_reg_neg; 399 400 st->chip_info = &ad5791_chip_info_tbl[spi_get_device_id(spi) 401 ->driver_data]; 402 403 404 st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv)) 405 | ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) | 406 AD5791_CTRL_BIN2SC; 407 408 ret = ad5791_spi_write(spi, AD5791_ADDR_CTRL, st->ctrl | 409 AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI); 410 if (ret) 411 goto error_disable_reg_neg; 412 413 spi_set_drvdata(spi, indio_dev); 414 indio_dev->dev.parent = &spi->dev; 415 indio_dev->info = &ad5791_info; 416 indio_dev->modes = INDIO_DIRECT_MODE; 417 indio_dev->channels 418 = &ad5791_channels[spi_get_device_id(spi)->driver_data]; 419 indio_dev->num_channels = 1; 420 indio_dev->name = spi_get_device_id(st->spi)->name; 421 ret = iio_device_register(indio_dev); 422 if (ret) 423 goto error_disable_reg_neg; 424 425 return 0; 426 427 error_disable_reg_neg: 428 if (!IS_ERR(st->reg_vss)) 429 regulator_disable(st->reg_vss); 430 error_disable_reg_pos: 431 if (!IS_ERR(st->reg_vdd)) 432 regulator_disable(st->reg_vdd); 433 return ret; 434 } 435 436 static int ad5791_remove(struct spi_device *spi) 437 { 438 struct iio_dev *indio_dev = spi_get_drvdata(spi); 439 struct ad5791_state *st = iio_priv(indio_dev); 440 441 iio_device_unregister(indio_dev); 442 if (!IS_ERR(st->reg_vdd)) 443 regulator_disable(st->reg_vdd); 444 445 if (!IS_ERR(st->reg_vss)) 446 regulator_disable(st->reg_vss); 447 448 return 0; 449 } 450 451 static const struct spi_device_id ad5791_id[] = { 452 {"ad5760", ID_AD5760}, 453 {"ad5780", ID_AD5780}, 454 {"ad5781", ID_AD5781}, 455 {"ad5790", ID_AD5791}, 456 {"ad5791", ID_AD5791}, 457 {} 458 }; 459 MODULE_DEVICE_TABLE(spi, ad5791_id); 460 461 static struct spi_driver ad5791_driver = { 462 .driver = { 463 .name = "ad5791", 464 .owner = THIS_MODULE, 465 }, 466 .probe = ad5791_probe, 467 .remove = ad5791_remove, 468 .id_table = ad5791_id, 469 }; 470 module_spi_driver(ad5791_driver); 471 472 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 473 MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC"); 474 MODULE_LICENSE("GPL v2"); 475