drivers/iio/dac/ad5504.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AD5504, AD5501 High Voltage Digital to Analog Converter
   4  *
   5  * Copyright 2011 Analog Devices Inc.
   6  */
   7
   8 #include <linux/interrupt.h>
   9 #include <linux/fs.h>
  10 #include <linux/device.h>
  11 #include <linux/kernel.h>
  12 #include <linux/spi/spi.h>
  13 #include <linux/slab.h>
  14 #include <linux/sysfs.h>
  15 #include <linux/regulator/consumer.h>
  16 #include <linux/module.h>
  17 #include <linux/bitops.h>
  18
  19 #include <linux/iio/iio.h>
  20 #include <linux/iio/sysfs.h>
  21 #include <linux/iio/events.h>
  22 #include <linux/iio/dac/ad5504.h>
  23
  24 #define AD5504_RES_MASK                 GENMASK(11, 0)
  25 #define AD5504_CMD_READ                 BIT(15)
  26 #define AD5504_CMD_WRITE                0
  27 #define AD5504_ADDR(addr)               ((addr) << 12)
  28
  29 /* Registers */
  30 #define AD5504_ADDR_NOOP                0
  31 #define AD5504_ADDR_DAC(x)              ((x) + 1)
  32 #define AD5504_ADDR_ALL_DAC             5
  33 #define AD5504_ADDR_CTRL                7
  34
  35 /* Control Register */
  36 #define AD5504_DAC_PWR(ch)              ((ch) << 2)
  37 #define AD5504_DAC_PWRDWN_MODE(mode)    ((mode) << 6)
  38 #define AD5504_DAC_PWRDN_20K            0
  39 #define AD5504_DAC_PWRDN_3STATE         1
  40
  41 /**
  42  * struct ad5504_state - driver instance specific data
  43  * @spi:                        spi_device
  44  * @reg:                supply regulator
  45  * @vref_mv:            actual reference voltage used
  46  * @pwr_down_mask:      power down mask
  47  * @pwr_down_mode:      current power down mode
  48  * @data:               transfer buffer
  49  */
  50 struct ad5504_state {
  51         struct spi_device               *spi;
  52         struct regulator                *reg;
  53         unsigned short                  vref_mv;
  54         unsigned                        pwr_down_mask;
  55         unsigned                        pwr_down_mode;
  56
  57         __be16                          data[2] ____cacheline_aligned;
  58 };
  59
  60 /*
  61  * ad5504_supported_device_ids:
  62  */
  63 enum ad5504_supported_device_ids {
  64         ID_AD5504,
  65         ID_AD5501,
  66 };
  67
  68 static int ad5504_spi_write(struct ad5504_state *st, u8 addr, u16 val)
  69 {
  70         st->data[0] = cpu_to_be16(AD5504_CMD_WRITE | AD5504_ADDR(addr) |
  71                               (val & AD5504_RES_MASK));
  72
  73         return spi_write(st->spi, &st->data[0], 2);
  74 }
  75
  76 static int ad5504_spi_read(struct ad5504_state *st, u8 addr)
  77 {
  78         int ret;
  79         struct spi_transfer t = {
  80             .tx_buf = &st->data[0],
  81             .rx_buf = &st->data[1],
  82             .len = 2,
  83         };
  84
  85         st->data[0] = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr));
  86         ret = spi_sync_transfer(st->spi, &t, 1);
  87         if (ret < 0)
  88                 return ret;
  89
  90         return be16_to_cpu(st->data[1]) & AD5504_RES_MASK;
  91 }
  92
  93 static int ad5504_read_raw(struct iio_dev *indio_dev,
  94                            struct iio_chan_spec const *chan,
  95                            int *val,
  96                            int *val2,
  97                            long m)
  98 {
  99         struct ad5504_state *st = iio_priv(indio_dev);
 100         int ret;
 101
 102         switch (m) {
 103         case IIO_CHAN_INFO_RAW:
 104                 ret = ad5504_spi_read(st, chan->address);
 105                 if (ret < 0)
 106                         return ret;
 107
 108                 *val = ret;
 109
 110                 return IIO_VAL_INT;
 111         case IIO_CHAN_INFO_SCALE:
 112                 *val = st->vref_mv;
 113                 *val2 = chan->scan_type.realbits;
 114                 return IIO_VAL_FRACTIONAL_LOG2;
 115         }
 116         return -EINVAL;
 117 }
 118
 119 static int ad5504_write_raw(struct iio_dev *indio_dev,
 120                                struct iio_chan_spec const *chan,
 121                                int val,
 122                                int val2,
 123                                long mask)
 124 {
 125         struct ad5504_state *st = iio_priv(indio_dev);
 126
 127         switch (mask) {
 128         case IIO_CHAN_INFO_RAW:
 129                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
 130                         return -EINVAL;
 131
 132                 return ad5504_spi_write(st, chan->address, val);
 133         default:
 134                 return -EINVAL;
 135         }
 136 }
 137
 138 static const char * const ad5504_powerdown_modes[] = {
 139         "20kohm_to_gnd",
 140         "three_state",
 141 };
 142
 143 static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
 144         const struct iio_chan_spec *chan)
 145 {
 146         struct ad5504_state *st = iio_priv(indio_dev);
 147
 148         return st->pwr_down_mode;
 149 }
 150
 151 static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
 152         const struct iio_chan_spec *chan, unsigned int mode)
 153 {
 154         struct ad5504_state *st = iio_priv(indio_dev);
 155
 156         st->pwr_down_mode = mode;
 157
 158         return 0;
 159 }
 160
 161 static const struct iio_enum ad5504_powerdown_mode_enum = {
 162         .items = ad5504_powerdown_modes,
 163         .num_items = ARRAY_SIZE(ad5504_powerdown_modes),
 164         .get = ad5504_get_powerdown_mode,
 165         .set = ad5504_set_powerdown_mode,
 166 };
 167
 168 static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
 169         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 170 {
 171         struct ad5504_state *st = iio_priv(indio_dev);
 172
 173         return sysfs_emit(buf, "%d\n",
 174                           !(st->pwr_down_mask & (1 << chan->channel)));
 175 }
 176
 177 static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
 178         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 179         size_t len)
 180 {
 181         bool pwr_down;
 182         int ret;
 183         struct ad5504_state *st = iio_priv(indio_dev);
 184
 185         ret = kstrtobool(buf, &pwr_down);
 186         if (ret)
 187                 return ret;
 188
 189         if (pwr_down)
 190                 st->pwr_down_mask &= ~(1 << chan->channel);
 191         else
 192                 st->pwr_down_mask |= (1 << chan->channel);
 193
 194         ret = ad5504_spi_write(st, AD5504_ADDR_CTRL,
 195                                 AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) |
 196                                 AD5504_DAC_PWR(st->pwr_down_mask));
 197
 198         /* writes to the CTRL register must be followed by a NOOP */
 199         ad5504_spi_write(st, AD5504_ADDR_NOOP, 0);
 200
 201         return ret ? ret : len;
 202 }
 203
 204 static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
 205 static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
 206
 207 static struct attribute *ad5504_ev_attributes[] = {
 208         &iio_const_attr_temp0_thresh_rising_value.dev_attr.attr,
 209         &iio_const_attr_temp0_thresh_rising_en.dev_attr.attr,
 210         NULL,
 211 };
 212
 213 static const struct attribute_group ad5504_ev_attribute_group = {
 214         .attrs = ad5504_ev_attributes,
 215 };
 216
 217 static irqreturn_t ad5504_event_handler(int irq, void *private)
 218 {
 219         iio_push_event(private,
 220                        IIO_UNMOD_EVENT_CODE(IIO_TEMP,
 221                                             0,
 222                                             IIO_EV_TYPE_THRESH,
 223                                             IIO_EV_DIR_RISING),
 224                        iio_get_time_ns(private));
 225
 226         return IRQ_HANDLED;
 227 }
 228
 229 static const struct iio_info ad5504_info = {
 230         .write_raw = ad5504_write_raw,
 231         .read_raw = ad5504_read_raw,
 232         .event_attrs = &ad5504_ev_attribute_group,
 233 };
 234
 235 static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
 236         {
 237                 .name = "powerdown",
 238                 .read = ad5504_read_dac_powerdown,
 239                 .write = ad5504_write_dac_powerdown,
 240                 .shared = IIO_SEPARATE,
 241         },
 242         IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
 243                  &ad5504_powerdown_mode_enum),
 244         IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5504_powerdown_mode_enum),
 245         { },
 246 };
 247
 248 #define AD5504_CHANNEL(_chan) { \
 249         .type = IIO_VOLTAGE, \
 250         .indexed = 1, \
 251         .output = 1, \
 252         .channel = (_chan), \
 253         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 254         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 255         .address = AD5504_ADDR_DAC(_chan), \
 256         .scan_type = { \
 257                 .sign = 'u', \
 258                 .realbits = 12, \
 259                 .storagebits = 16, \
 260         }, \
 261         .ext_info = ad5504_ext_info, \
 262 }
 263
 264 static const struct iio_chan_spec ad5504_channels[] = {
 265         AD5504_CHANNEL(0),
 266         AD5504_CHANNEL(1),
 267         AD5504_CHANNEL(2),
 268         AD5504_CHANNEL(3),
 269 };
 270
 271 static int ad5504_probe(struct spi_device *spi)
 272 {
 273         struct ad5504_platform_data *pdata = spi->dev.platform_data;
 274         struct iio_dev *indio_dev;
 275         struct ad5504_state *st;
 276         struct regulator *reg;
 277         int ret, voltage_uv = 0;
 278
 279         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 280         if (!indio_dev)
 281                 return -ENOMEM;
 282         reg = devm_regulator_get(&spi->dev, "vcc");
 283         if (!IS_ERR(reg)) {
 284                 ret = regulator_enable(reg);
 285                 if (ret)
 286                         return ret;
 287
 288                 ret = regulator_get_voltage(reg);
 289                 if (ret < 0)
 290                         goto error_disable_reg;
 291
 292                 voltage_uv = ret;
 293         }
 294
 295         spi_set_drvdata(spi, indio_dev);
 296         st = iio_priv(indio_dev);
 297         if (voltage_uv)
 298                 st->vref_mv = voltage_uv / 1000;
 299         else if (pdata)
 300                 st->vref_mv = pdata->vref_mv;
 301         else
 302                 dev_warn(&spi->dev, "reference voltage unspecified\n");
 303
 304         st->reg = reg;
 305         st->spi = spi;
 306         indio_dev->name = spi_get_device_id(st->spi)->name;
 307         indio_dev->info = &ad5504_info;
 308         if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
 309                 indio_dev->num_channels = 1;
 310         else
 311                 indio_dev->num_channels = 4;
 312         indio_dev->channels = ad5504_channels;
 313         indio_dev->modes = INDIO_DIRECT_MODE;
 314
 315         if (spi->irq) {
 316                 ret = devm_request_threaded_irq(&spi->dev, spi->irq,
 317                                            NULL,
 318                                            &ad5504_event_handler,
 319                                            IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 320                                            spi_get_device_id(st->spi)->name,
 321                                            indio_dev);
 322                 if (ret)
 323                         goto error_disable_reg;
 324         }
 325
 326         ret = iio_device_register(indio_dev);
 327         if (ret)
 328                 goto error_disable_reg;
 329
 330         return 0;
 331
 332 error_disable_reg:
 333         if (!IS_ERR(reg))
 334                 regulator_disable(reg);
 335
 336         return ret;
 337 }
 338
 339 static void ad5504_remove(struct spi_device *spi)
 340 {
 341         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 342         struct ad5504_state *st = iio_priv(indio_dev);
 343
 344         iio_device_unregister(indio_dev);
 345
 346         if (!IS_ERR(st->reg))
 347                 regulator_disable(st->reg);
 348 }
 349
 350 static const struct spi_device_id ad5504_id[] = {
 351         {"ad5504", ID_AD5504},
 352         {"ad5501", ID_AD5501},
 353         {}
 354 };
 355 MODULE_DEVICE_TABLE(spi, ad5504_id);
 356
 357 static struct spi_driver ad5504_driver = {
 358         .driver = {
 359                    .name = "ad5504",
 360                    },
 361         .probe = ad5504_probe,
 362         .remove = ad5504_remove,
 363         .id_table = ad5504_id,
 364 };
 365 module_spi_driver(ad5504_driver);
 366
 367 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 368 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
 369 MODULE_LICENSE("GPL v2");