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_transfer t[] = { 105 { 106 .tx_buf = &st->data[0], 107 .len = 2, 108 .cs_change = 1, 109 }, { 110 .tx_buf = &st->data[1], 111 .rx_buf = &st->data[1], 112 .len = 2, 113 }, 114 }; 115 116 mutex_lock(&indio_dev->mlock); 117 st->data[0] = cpu_to_be16(addr << 12); 118 st->data[1] = cpu_to_be16(AD5449_CMD_NOOP); 119 120 ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); 121 if (ret < 0) 122 goto out_unlock; 123 124 *val = be16_to_cpu(st->data[1]); 125 126 out_unlock: 127 mutex_unlock(&indio_dev->mlock); 128 return ret; 129 } 130 131 static int ad5449_read_raw(struct iio_dev *indio_dev, 132 struct iio_chan_spec const *chan, int *val, int *val2, long info) 133 { 134 struct ad5449 *st = iio_priv(indio_dev); 135 struct regulator_bulk_data *reg; 136 int scale_uv; 137 int ret; 138 139 switch (info) { 140 case IIO_CHAN_INFO_RAW: 141 if (st->has_sdo) { 142 ret = ad5449_read(indio_dev, 143 AD5449_CMD_READ(chan->address), val); 144 if (ret) 145 return ret; 146 *val &= 0xfff; 147 } else { 148 *val = st->dac_cache[chan->address]; 149 } 150 151 return IIO_VAL_INT; 152 case IIO_CHAN_INFO_SCALE: 153 reg = &st->vref_reg[chan->channel]; 154 scale_uv = regulator_get_voltage(reg->consumer); 155 if (scale_uv < 0) 156 return scale_uv; 157 158 *val = scale_uv / 1000; 159 *val2 = chan->scan_type.realbits; 160 161 return IIO_VAL_FRACTIONAL_LOG2; 162 default: 163 break; 164 } 165 166 return -EINVAL; 167 } 168 169 static int ad5449_write_raw(struct iio_dev *indio_dev, 170 struct iio_chan_spec const *chan, int val, int val2, long info) 171 { 172 struct ad5449 *st = iio_priv(indio_dev); 173 int ret; 174 175 switch (info) { 176 case IIO_CHAN_INFO_RAW: 177 if (val < 0 || val >= (1 << chan->scan_type.realbits)) 178 return -EINVAL; 179 180 ret = ad5449_write(indio_dev, 181 AD5449_CMD_LOAD_AND_UPDATE(chan->address), 182 val << chan->scan_type.shift); 183 if (ret == 0) 184 st->dac_cache[chan->address] = val; 185 break; 186 default: 187 ret = -EINVAL; 188 } 189 190 return ret; 191 } 192 193 static const struct iio_info ad5449_info = { 194 .read_raw = ad5449_read_raw, 195 .write_raw = ad5449_write_raw, 196 .driver_module = THIS_MODULE, 197 }; 198 199 #define AD5449_CHANNEL(chan, bits) { \ 200 .type = IIO_VOLTAGE, \ 201 .indexed = 1, \ 202 .output = 1, \ 203 .channel = (chan), \ 204 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 205 BIT(IIO_CHAN_INFO_SCALE), \ 206 .address = (chan), \ 207 .scan_type = IIO_ST('u', (bits), 16, 12 - (bits)), \ 208 } 209 210 #define DECLARE_AD5449_CHANNELS(name, bits) \ 211 const struct iio_chan_spec name[] = { \ 212 AD5449_CHANNEL(0, bits), \ 213 AD5449_CHANNEL(1, bits), \ 214 } 215 216 static DECLARE_AD5449_CHANNELS(ad5429_channels, 8); 217 static DECLARE_AD5449_CHANNELS(ad5439_channels, 10); 218 static DECLARE_AD5449_CHANNELS(ad5449_channels, 12); 219 220 static const struct ad5449_chip_info ad5449_chip_info[] = { 221 [ID_AD5426] = { 222 .channels = ad5429_channels, 223 .num_channels = 1, 224 .has_ctrl = false, 225 }, 226 [ID_AD5429] = { 227 .channels = ad5429_channels, 228 .num_channels = 2, 229 .has_ctrl = true, 230 }, 231 [ID_AD5432] = { 232 .channels = ad5439_channels, 233 .num_channels = 1, 234 .has_ctrl = false, 235 }, 236 [ID_AD5439] = { 237 .channels = ad5439_channels, 238 .num_channels = 2, 239 .has_ctrl = true, 240 }, 241 [ID_AD5443] = { 242 .channels = ad5449_channels, 243 .num_channels = 1, 244 .has_ctrl = false, 245 }, 246 [ID_AD5449] = { 247 .channels = ad5449_channels, 248 .num_channels = 2, 249 .has_ctrl = true, 250 }, 251 }; 252 253 static const char *ad5449_vref_name(struct ad5449 *st, int n) 254 { 255 if (st->chip_info->num_channels == 1) 256 return "VREF"; 257 258 if (n == 0) 259 return "VREFA"; 260 else 261 return "VREFB"; 262 } 263 264 static int ad5449_spi_probe(struct spi_device *spi) 265 { 266 struct ad5449_platform_data *pdata = spi->dev.platform_data; 267 const struct spi_device_id *id = spi_get_device_id(spi); 268 struct iio_dev *indio_dev; 269 struct ad5449 *st; 270 unsigned int i; 271 int ret; 272 273 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 274 if (indio_dev == NULL) 275 return -ENOMEM; 276 277 st = iio_priv(indio_dev); 278 spi_set_drvdata(spi, indio_dev); 279 280 st->chip_info = &ad5449_chip_info[id->driver_data]; 281 st->spi = spi; 282 283 for (i = 0; i < st->chip_info->num_channels; ++i) 284 st->vref_reg[i].supply = ad5449_vref_name(st, i); 285 286 ret = devm_regulator_bulk_get(&spi->dev, st->chip_info->num_channels, 287 st->vref_reg); 288 if (ret) 289 return ret; 290 291 ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg); 292 if (ret) 293 return ret; 294 295 indio_dev->dev.parent = &spi->dev; 296 indio_dev->name = id->name; 297 indio_dev->info = &ad5449_info; 298 indio_dev->modes = INDIO_DIRECT_MODE; 299 indio_dev->channels = st->chip_info->channels; 300 indio_dev->num_channels = st->chip_info->num_channels; 301 302 if (st->chip_info->has_ctrl) { 303 unsigned int ctrl = 0x00; 304 if (pdata) { 305 if (pdata->hardware_clear_to_midscale) 306 ctrl |= AD5449_CTRL_HCLR_TO_MIDSCALE; 307 ctrl |= pdata->sdo_mode << AD5449_CTRL_SDO_OFFSET; 308 st->has_sdo = pdata->sdo_mode != AD5449_SDO_DISABLED; 309 } else { 310 st->has_sdo = true; 311 } 312 ad5449_write(indio_dev, AD5449_CMD_CTRL, ctrl); 313 } 314 315 ret = iio_device_register(indio_dev); 316 if (ret) 317 goto error_disable_reg; 318 319 return 0; 320 321 error_disable_reg: 322 regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg); 323 324 return ret; 325 } 326 327 static int ad5449_spi_remove(struct spi_device *spi) 328 { 329 struct iio_dev *indio_dev = spi_get_drvdata(spi); 330 struct ad5449 *st = iio_priv(indio_dev); 331 332 iio_device_unregister(indio_dev); 333 334 regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg); 335 336 return 0; 337 } 338 339 static const struct spi_device_id ad5449_spi_ids[] = { 340 { "ad5415", ID_AD5449 }, 341 { "ad5426", ID_AD5426 }, 342 { "ad5429", ID_AD5429 }, 343 { "ad5432", ID_AD5432 }, 344 { "ad5439", ID_AD5439 }, 345 { "ad5443", ID_AD5443 }, 346 { "ad5449", ID_AD5449 }, 347 {} 348 }; 349 MODULE_DEVICE_TABLE(spi, ad5449_spi_ids); 350 351 static struct spi_driver ad5449_spi_driver = { 352 .driver = { 353 .name = "ad5449", 354 .owner = THIS_MODULE, 355 }, 356 .probe = ad5449_spi_probe, 357 .remove = ad5449_spi_remove, 358 .id_table = ad5449_spi_ids, 359 }; 360 module_spi_driver(ad5449_spi_driver); 361 362 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 363 MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs"); 364 MODULE_LICENSE("GPL v2"); 365