drivers/staging/iio/dac/ad5446.c

   1 /*
   2  * AD5446 SPI DAC driver
   3  *
   4  * Copyright 2010 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8
   9 #include <linux/interrupt.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/device.h>
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/sysfs.h>
  15 #include <linux/list.h>
  16 #include <linux/spi/spi.h>
  17 #include <linux/regulator/consumer.h>
  18 #include <linux/err.h>
  19
  20 #include "../iio.h"
  21 #include "../sysfs.h"
  22 #include "dac.h"
  23
  24 #include "ad5446.h"
  25
  26 static void ad5446_store_sample(struct ad5446_state *st, unsigned val)
  27 {
  28         st->data.d16 = cpu_to_be16(AD5446_LOAD |
  29                                         (val << st->chip_info->left_shift));
  30 }
  31
  32 static void ad5542_store_sample(struct ad5446_state *st, unsigned val)
  33 {
  34         st->data.d16 = cpu_to_be16(val << st->chip_info->left_shift);
  35 }
  36
  37 static void ad5620_store_sample(struct ad5446_state *st, unsigned val)
  38 {
  39         st->data.d16 = cpu_to_be16(AD5620_LOAD |
  40                                         (val << st->chip_info->left_shift));
  41 }
  42
  43 static void ad5660_store_sample(struct ad5446_state *st, unsigned val)
  44 {
  45         val |= AD5660_LOAD;
  46         st->data.d24[0] = (val >> 16) & 0xFF;
  47         st->data.d24[1] = (val >> 8) & 0xFF;
  48         st->data.d24[2] = val & 0xFF;
  49 }
  50
  51 static ssize_t ad5446_write(struct device *dev,
  52                 struct device_attribute *attr,
  53                 const char *buf,
  54                 size_t len)
  55 {
  56         struct iio_dev *dev_info = dev_get_drvdata(dev);
  57         struct ad5446_state *st = dev_info->dev_data;
  58         int ret;
  59         long val;
  60
  61         ret = strict_strtol(buf, 10, &val);
  62         if (ret)
  63                 goto error_ret;
  64
  65         if (val > RES_MASK(st->chip_info->bits)) {
  66                 ret = -EINVAL;
  67                 goto error_ret;
  68         }
  69
  70         mutex_lock(&dev_info->mlock);
  71         st->chip_info->store_sample(st, val);
  72         ret = spi_sync(st->spi, &st->msg);
  73         mutex_unlock(&dev_info->mlock);
  74
  75 error_ret:
  76         return ret ? ret : len;
  77 }
  78
  79 static IIO_DEV_ATTR_OUT_RAW(0, ad5446_write, 0);
  80
  81 static ssize_t ad5446_show_scale(struct device *dev,
  82                                 struct device_attribute *attr,
  83                                 char *buf)
  84 {
  85         struct iio_dev *dev_info = dev_get_drvdata(dev);
  86         struct ad5446_state *st = iio_dev_get_devdata(dev_info);
  87         /* Corresponds to Vref / 2^(bits) */
  88         unsigned int scale_uv = (st->vref_mv * 1000) >> st->chip_info->bits;
  89
  90         return sprintf(buf, "%d.%d\n", scale_uv / 1000, scale_uv % 1000);
  91 }
  92 static IIO_DEVICE_ATTR(out_scale, S_IRUGO, ad5446_show_scale, NULL, 0);
  93
  94 static ssize_t ad5446_show_name(struct device *dev,
  95                                  struct device_attribute *attr,
  96                                  char *buf)
  97 {
  98         struct iio_dev *dev_info = dev_get_drvdata(dev);
  99         struct ad5446_state *st = iio_dev_get_devdata(dev_info);
 100
 101         return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
 102 }
 103 static IIO_DEVICE_ATTR(name, S_IRUGO, ad5446_show_name, NULL, 0);
 104
 105 static struct attribute *ad5446_attributes[] = {
 106         &iio_dev_attr_out0_raw.dev_attr.attr,
 107         &iio_dev_attr_out_scale.dev_attr.attr,
 108         &iio_dev_attr_name.dev_attr.attr,
 109         NULL,
 110 };
 111
 112 static const struct attribute_group ad5446_attribute_group = {
 113         .attrs = ad5446_attributes,
 114 };
 115
 116 static const struct ad5446_chip_info ad5446_chip_info_tbl[] = {
 117         [ID_AD5444] = {
 118                 .bits = 12,
 119                 .storagebits = 16,
 120                 .left_shift = 2,
 121                 .store_sample = ad5446_store_sample,
 122         },
 123         [ID_AD5446] = {
 124                 .bits = 14,
 125                 .storagebits = 16,
 126                 .left_shift = 0,
 127                 .store_sample = ad5446_store_sample,
 128         },
 129         [ID_AD5542A] = {
 130                 .bits = 16,
 131                 .storagebits = 16,
 132                 .left_shift = 0,
 133                 .store_sample = ad5542_store_sample,
 134         },
 135         [ID_AD5512A] = {
 136                 .bits = 12,
 137                 .storagebits = 16,
 138                 .left_shift = 4,
 139                 .store_sample = ad5542_store_sample,
 140         },
 141         [ID_AD5620_2500] = {
 142                 .bits = 12,
 143                 .storagebits = 16,
 144                 .left_shift = 2,
 145                 .int_vref_mv = 2500,
 146                 .store_sample = ad5620_store_sample,
 147         },
 148         [ID_AD5620_1250] = {
 149                 .bits = 12,
 150                 .storagebits = 16,
 151                 .left_shift = 2,
 152                 .int_vref_mv = 1250,
 153                 .store_sample = ad5620_store_sample,
 154         },
 155         [ID_AD5640_2500] = {
 156                 .bits = 14,
 157                 .storagebits = 16,
 158                 .left_shift = 0,
 159                 .int_vref_mv = 2500,
 160                 .store_sample = ad5620_store_sample,
 161         },
 162         [ID_AD5640_1250] = {
 163                 .bits = 14,
 164                 .storagebits = 16,
 165                 .left_shift = 0,
 166                 .int_vref_mv = 1250,
 167                 .store_sample = ad5620_store_sample,
 168         },
 169         [ID_AD5660_2500] = {
 170                 .bits = 16,
 171                 .storagebits = 24,
 172                 .left_shift = 0,
 173                 .int_vref_mv = 2500,
 174                 .store_sample = ad5660_store_sample,
 175         },
 176         [ID_AD5660_1250] = {
 177                 .bits = 16,
 178                 .storagebits = 24,
 179                 .left_shift = 0,
 180                 .int_vref_mv = 1250,
 181                 .store_sample = ad5660_store_sample,
 182         },
 183 };
 184
 185 static int __devinit ad5446_probe(struct spi_device *spi)
 186 {
 187         struct ad5446_state *st;
 188         int ret, voltage_uv = 0;
 189
 190         st = kzalloc(sizeof(*st), GFP_KERNEL);
 191         if (st == NULL) {
 192                 ret = -ENOMEM;
 193                 goto error_ret;
 194         }
 195
 196         st->reg = regulator_get(&spi->dev, "vcc");
 197         if (!IS_ERR(st->reg)) {
 198                 ret = regulator_enable(st->reg);
 199                 if (ret)
 200                         goto error_put_reg;
 201
 202                 voltage_uv = regulator_get_voltage(st->reg);
 203         }
 204
 205         st->chip_info =
 206                 &ad5446_chip_info_tbl[spi_get_device_id(spi)->driver_data];
 207
 208         spi_set_drvdata(spi, st);
 209
 210         st->spi = spi;
 211
 212         st->indio_dev = iio_allocate_device();
 213         if (st->indio_dev == NULL) {
 214                 ret = -ENOMEM;
 215                 goto error_disable_reg;
 216         }
 217
 218         /* Estabilish that the iio_dev is a child of the spi device */
 219         st->indio_dev->dev.parent = &spi->dev;
 220         st->indio_dev->attrs = &ad5446_attribute_group;
 221         st->indio_dev->dev_data = (void *)(st);
 222         st->indio_dev->driver_module = THIS_MODULE;
 223         st->indio_dev->modes = INDIO_DIRECT_MODE;
 224
 225         /* Setup default message */
 226
 227         st->xfer.tx_buf = &st->data;
 228         st->xfer.len = st->chip_info->storagebits / 8;
 229
 230         spi_message_init(&st->msg);
 231         spi_message_add_tail(&st->xfer, &st->msg);
 232
 233         switch (spi_get_device_id(spi)->driver_data) {
 234                 case ID_AD5620_2500:
 235                 case ID_AD5620_1250:
 236                 case ID_AD5640_2500:
 237                 case ID_AD5640_1250:
 238                 case ID_AD5660_2500:
 239                 case ID_AD5660_1250:
 240                         st->vref_mv = st->chip_info->int_vref_mv;
 241                         break;
 242                 default:
 243                         if (voltage_uv)
 244                                 st->vref_mv = voltage_uv / 1000;
 245                         else
 246                                 dev_warn(&spi->dev,
 247                                          "reference voltage unspecified\n");
 248         }
 249
 250         ret = iio_device_register(st->indio_dev);
 251         if (ret)
 252                 goto error_free_device;
 253
 254         return 0;
 255
 256 error_free_device:
 257         iio_free_device(st->indio_dev);
 258 error_disable_reg:
 259         if (!IS_ERR(st->reg))
 260                 regulator_disable(st->reg);
 261 error_put_reg:
 262         if (!IS_ERR(st->reg))
 263                 regulator_put(st->reg);
 264         kfree(st);
 265 error_ret:
 266         return ret;
 267 }
 268
 269 static int ad5446_remove(struct spi_device *spi)
 270 {
 271         struct ad5446_state *st = spi_get_drvdata(spi);
 272         struct iio_dev *indio_dev = st->indio_dev;
 273
 274         iio_device_unregister(indio_dev);
 275         if (!IS_ERR(st->reg)) {
 276                 regulator_disable(st->reg);
 277                 regulator_put(st->reg);
 278         }
 279         kfree(st);
 280         return 0;
 281 }
 282
 283 static const struct spi_device_id ad5446_id[] = {
 284         {"ad5444", ID_AD5444},
 285         {"ad5446", ID_AD5446},
 286         {"ad5542a", ID_AD5542A},
 287         {"ad5512a", ID_AD5512A},
 288         {"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
 289         {"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
 290         {"ad5640-2500", ID_AD5640_2500},
 291         {"ad5640-1250", ID_AD5640_1250},
 292         {"ad5660-2500", ID_AD5660_2500},
 293         {"ad5660-1250", ID_AD5660_1250},
 294         {}
 295 };
 296
 297 static struct spi_driver ad5446_driver = {
 298         .driver = {
 299                 .name   = "ad5446",
 300                 .bus    = &spi_bus_type,
 301                 .owner  = THIS_MODULE,
 302         },
 303         .probe          = ad5446_probe,
 304         .remove         = __devexit_p(ad5446_remove),
 305         .id_table       = ad5446_id,
 306 };
 307
 308 static int __init ad5446_init(void)
 309 {
 310         return spi_register_driver(&ad5446_driver);
 311 }
 312 module_init(ad5446_init);
 313
 314 static void __exit ad5446_exit(void)
 315 {
 316         spi_unregister_driver(&ad5446_driver);
 317 }
 318 module_exit(ad5446_exit);
 319
 320 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 321 MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
 322 MODULE_LICENSE("GPL v2");
 323 MODULE_ALIAS("spi:ad5446");