1 /* 2 * AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog 3 * Converter driver. 4 * 5 * Copyright 2012 Analog Devices Inc. 6 * Author: Lars-Peter Clausen <lars@metafoo.de> 7 * 8 * Licensed under the GPL-2. 9 */ 10 11 #include <linux/device.h> 12 #include <linux/err.h> 13 #include <linux/module.h> 14 #include <linux/kernel.h> 15 #include <linux/spi/spi.h> 16 #include <linux/slab.h> 17 #include <linux/sysfs.h> 18 #include <linux/regulator/consumer.h> 19 #include <asm/unaligned.h> 20 21 #include <linux/iio/iio.h> 22 #include <linux/iio/sysfs.h> 23 24 #include <linux/platform_data/ad5449.h> 25 26 #define AD5449_MAX_CHANNELS 2 27 #define AD5449_MAX_VREFS 2 28 29 #define AD5449_CMD_NOOP 0x0 30 #define AD5449_CMD_LOAD_AND_UPDATE(x) (0x1 + (x) * 3) 31 #define AD5449_CMD_READ(x) (0x2 + (x) * 3) 32 #define AD5449_CMD_LOAD(x) (0x3 + (x) * 3) 33 #define AD5449_CMD_CTRL 13 34 35 #define AD5449_CTRL_SDO_OFFSET 10 36 #define AD5449_CTRL_DAISY_CHAIN BIT(9) 37 #define AD5449_CTRL_HCLR_TO_MIDSCALE BIT(8) 38 #define AD5449_CTRL_SAMPLE_RISING BIT(7) 39 40 /** 41 * struct ad5449_chip_info - chip specific information 42 * @channels: Channel specification 43 * @num_channels: Number of channels 44 * @has_ctrl: Chip has a control register 45 */ 46 struct ad5449_chip_info { 47 const struct iio_chan_spec *channels; 48 unsigned int num_channels; 49 bool has_ctrl; 50 }; 51 52 /** 53 * struct ad5449 - driver instance specific data 54 * @spi: the SPI device for this driver instance 55 * @chip_info: chip model specific constants, available modes etc 56 * @vref_reg: vref supply regulators 57 * @has_sdo: whether the SDO line is connected 58 * @dac_cache: Cache for the DAC values 59 * @data: spi transfer buffers 60 */ 61 struct ad5449 { 62 struct spi_device *spi; 63 const struct ad5449_chip_info *chip_info; 64 struct regulator_bulk_data vref_reg[AD5449_MAX_VREFS]; 65 66 bool has_sdo; 67 uint16_t dac_cache[AD5449_MAX_CHANNELS]; 68 69 /* 70 * DMA (thus cache coherency maintenance) requires the 71 * transfer buffers to live in their own cache lines. 72 */ 73 __be16 data[2] ____cacheline_aligned; 74 }; 75 76 enum ad5449_type { 77 ID_AD5426, 78 ID_AD5429, 79 ID_AD5432, 80 ID_AD5439, 81 ID_AD5443, 82 ID_AD5449, 83 }; 84 85 static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr, 86 unsigned int val) 87 { 88 struct ad5449 *st = iio_priv(indio_dev); 89 int ret; 90 91 mutex_lock(&indio_dev->mlock); 92 st->data[0] = cpu_to_be16((addr << 12) | val); 93 ret = spi_write(st->spi, st->data, 2); 94 mutex_unlock(&indio_dev->mlock); 95 96 return ret; 97 } 98 99 static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr, 100 unsigned int *val) 101 { 102 struct ad5449 *st = iio_priv(indio_dev); 103 int ret; 104 struct spi_message msg; 105 struct spi_transfer t[] = { 106 { 107 .tx_buf = &st->data[0], 108 .len = 2, 109 .cs_change = 1, 110 }, { 111 .tx_buf = &st->data[1], 112 .rx_buf = &st->data[1], 113 .len = 2, 114 }, 115 }; 116 117 spi_message_init(&msg); 118 spi_message_add_tail(&t[0], &msg); 119 spi_message_add_tail(&t[1], &msg); 120 121 mutex_lock(&indio_dev->mlock); 122 st->data[0] = cpu_to_be16(addr << 12); 123 st->data[1] = cpu_to_be16(AD5449_CMD_NOOP); 124 125 ret = spi_sync(st->spi, &msg); 126 if (ret < 0) 127 goto out_unlock; 128 129 *val = be16_to_cpu(st->data[1]); 130 131 out_unlock: 132 mutex_unlock(&indio_dev->mlock); 133 return ret; 134 } 135 136 static int ad5449_read_raw(struct iio_dev *indio_dev, 137 struct iio_chan_spec const *chan, int *val, int *val2, long info) 138 { 139 struct ad5449 *st = iio_priv(indio_dev); 140 struct regulator_bulk_data *reg; 141 int scale_uv; 142 int ret; 143 144 switch (info) { 145 case IIO_CHAN_INFO_RAW: 146 if (st->has_sdo) { 147 ret = ad5449_read(indio_dev, 148 AD5449_CMD_READ(chan->address), val); 149 if (ret) 150 return ret; 151 *val &= 0xfff; 152 } else { 153 *val = st->dac_cache[chan->address]; 154 } 155 156 return IIO_VAL_INT; 157 case IIO_CHAN_INFO_SCALE: 158 reg = &st->vref_reg[chan->channel]; 159 scale_uv = regulator_get_voltage(reg->consumer); 160 if (scale_uv < 0) 161 return scale_uv; 162 163 *val = scale_uv / 1000; 164 *val2 = chan->scan_type.realbits; 165 166 return IIO_VAL_FRACTIONAL_LOG2; 167 default: 168 break; 169 } 170 171 return -EINVAL; 172 } 173 174 static int ad5449_write_raw(struct iio_dev *indio_dev, 175 struct iio_chan_spec const *chan, int val, int val2, long info) 176 { 177 struct ad5449 *st = iio_priv(indio_dev); 178 int ret; 179 180 switch (info) { 181 case IIO_CHAN_INFO_RAW: 182 if (val < 0 || val >= (1 << chan->scan_type.realbits)) 183 return -EINVAL; 184 185 ret = ad5449_write(indio_dev, 186 AD5449_CMD_LOAD_AND_UPDATE(chan->address), 187 val << chan->scan_type.shift); 188 if (ret == 0) 189 st->dac_cache[chan->address] = val; 190 break; 191 default: 192 ret = -EINVAL; 193 } 194 195 return ret; 196 } 197 198 static const struct iio_info ad5449_info = { 199 .read_raw = ad5449_read_raw, 200 .write_raw = ad5449_write_raw, 201 .driver_module = THIS_MODULE, 202 }; 203 204 #define AD5449_CHANNEL(chan, bits) { \ 205 .type = IIO_VOLTAGE, \ 206 .indexed = 1, \ 207 .output = 1, \ 208 .channel = (chan), \ 209 .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ 210 IIO_CHAN_INFO_SCALE_SEPARATE_BIT, \ 211 .address = (chan), \ 212 .scan_type = IIO_ST('u', (bits), 16, 12 - (bits)), \ 213 } 214 215 #define DECLARE_AD5449_CHANNELS(name, bits) \ 216 const struct iio_chan_spec name[] = { \ 217 AD5449_CHANNEL(0, bits), \ 218 AD5449_CHANNEL(1, bits), \ 219 } 220 221 static DECLARE_AD5449_CHANNELS(ad5429_channels, 8); 222 static DECLARE_AD5449_CHANNELS(ad5439_channels, 10); 223 static DECLARE_AD5449_CHANNELS(ad5449_channels, 12); 224 225 static const struct ad5449_chip_info ad5449_chip_info[] = { 226 [ID_AD5426] = { 227 .channels = ad5429_channels, 228 .num_channels = 1, 229 .has_ctrl = false, 230 }, 231 [ID_AD5429] = { 232 .channels = ad5429_channels, 233 .num_channels = 2, 234 .has_ctrl = true, 235 }, 236 [ID_AD5432] = { 237 .channels = ad5439_channels, 238 .num_channels = 1, 239 .has_ctrl = false, 240 }, 241 [ID_AD5439] = { 242 .channels = ad5439_channels, 243 .num_channels = 2, 244 .has_ctrl = true, 245 }, 246 [ID_AD5443] = { 247 .channels = ad5449_channels, 248 .num_channels = 1, 249 .has_ctrl = false, 250 }, 251 [ID_AD5449] = { 252 .channels = ad5449_channels, 253 .num_channels = 2, 254 .has_ctrl = true, 255 }, 256 }; 257 258 static const char *ad5449_vref_name(struct ad5449 *st, int n) 259 { 260 if (st->chip_info->num_channels == 1) 261 return "VREF"; 262 263 if (n == 0) 264 return "VREFA"; 265 else 266 return "VREFB"; 267 } 268 269 static int __devinit ad5449_spi_probe(struct spi_device *spi) 270 { 271 struct ad5449_platform_data *pdata = spi->dev.platform_data; 272 const struct spi_device_id *id = spi_get_device_id(spi); 273 struct iio_dev *indio_dev; 274 struct ad5449 *st; 275 unsigned int i; 276 int ret; 277 278 indio_dev = iio_device_alloc(sizeof(*st)); 279 if (indio_dev == NULL) 280 return -ENOMEM; 281 282 st = iio_priv(indio_dev); 283 spi_set_drvdata(spi, indio_dev); 284 285 st->chip_info = &ad5449_chip_info[id->driver_data]; 286 st->spi = spi; 287 288 for (i = 0; i < st->chip_info->num_channels; ++i) 289 st->vref_reg[i].supply = ad5449_vref_name(st, i); 290 291 ret = regulator_bulk_get(&spi->dev, st->chip_info->num_channels, 292 st->vref_reg); 293 if (ret) 294 goto error_free; 295 296 ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg); 297 if (ret) 298 goto error_free_reg; 299 300 indio_dev->dev.parent = &spi->dev; 301 indio_dev->name = id->name; 302 indio_dev->info = &ad5449_info; 303 indio_dev->modes = INDIO_DIRECT_MODE; 304 indio_dev->channels = st->chip_info->channels; 305 indio_dev->num_channels = st->chip_info->num_channels; 306 307 if (st->chip_info->has_ctrl) { 308 unsigned int ctrl = 0x00; 309 if (pdata) { 310 if (pdata->hardware_clear_to_midscale) 311 ctrl |= AD5449_CTRL_HCLR_TO_MIDSCALE; 312 ctrl |= pdata->sdo_mode << AD5449_CTRL_SDO_OFFSET; 313 st->has_sdo = pdata->sdo_mode != AD5449_SDO_DISABLED; 314 } else { 315 st->has_sdo = true; 316 } 317 ad5449_write(indio_dev, AD5449_CMD_CTRL, ctrl); 318 } 319 320 ret = iio_device_register(indio_dev); 321 if (ret) 322 goto error_disable_reg; 323 324 return 0; 325 326 error_disable_reg: 327 regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg); 328 error_free_reg: 329 regulator_bulk_free(st->chip_info->num_channels, st->vref_reg); 330 error_free: 331 iio_device_free(indio_dev); 332 333 return ret; 334 } 335 336 static int __devexit ad5449_spi_remove(struct spi_device *spi) 337 { 338 struct iio_dev *indio_dev = spi_get_drvdata(spi); 339 struct ad5449 *st = iio_priv(indio_dev); 340 341 iio_device_unregister(indio_dev); 342 343 regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg); 344 regulator_bulk_free(st->chip_info->num_channels, st->vref_reg); 345 346 iio_device_free(indio_dev); 347 348 return 0; 349 } 350 351 static const struct spi_device_id ad5449_spi_ids[] = { 352 { "ad5415", ID_AD5449 }, 353 { "ad5426", ID_AD5426 }, 354 { "ad5429", ID_AD5429 }, 355 { "ad5432", ID_AD5432 }, 356 { "ad5439", ID_AD5439 }, 357 { "ad5443", ID_AD5443 }, 358 { "ad5449", ID_AD5449 }, 359 {} 360 }; 361 MODULE_DEVICE_TABLE(spi, ad5449_spi_ids); 362 363 static struct spi_driver ad5449_spi_driver = { 364 .driver = { 365 .name = "ad5449", 366 .owner = THIS_MODULE, 367 }, 368 .probe = ad5449_spi_probe, 369 .remove = __devexit_p(ad5449_spi_remove), 370 .id_table = ad5449_spi_ids, 371 }; 372 module_spi_driver(ad5449_spi_driver); 373 374 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 375 MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs"); 376 MODULE_LICENSE("GPL v2"); 377