drivers/iio/dac/ad5624r_spi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver
   4  *
   5  * Copyright 2010-2011 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
  18 #include <linux/iio/iio.h>
  19 #include <linux/iio/sysfs.h>
  20
  21 #include <linux/unaligned.h>
  22
  23 #include "ad5624r.h"
  24
  25 static int ad5624r_spi_write(struct spi_device *spi,
  26                              u8 cmd, u8 addr, u16 val, u8 shift)
  27 {
  28         u32 data;
  29         u8 msg[3];
  30
  31         /*
  32          * The input shift register is 24 bits wide. The first two bits are
  33          * don't care bits. The next three are the command bits, C2 to C0,
  34          * followed by the 3-bit DAC address, A2 to A0, and then the
  35          * 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
  36          * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,
  37          * for the AD5664R, AD5644R, and AD5624R, respectively.
  38          */
  39         data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << shift);
  40         put_unaligned_be24(data, &msg[0]);
  41
  42         return spi_write(spi, msg, sizeof(msg));
  43 }
  44
  45 static int ad5624r_read_raw(struct iio_dev *indio_dev,
  46                            struct iio_chan_spec const *chan,
  47                            int *val,
  48                            int *val2,
  49                            long m)
  50 {
  51         struct ad5624r_state *st = iio_priv(indio_dev);
  52
  53         switch (m) {
  54         case IIO_CHAN_INFO_SCALE:
  55                 *val = st->vref_mv;
  56                 *val2 = chan->scan_type.realbits;
  57                 return IIO_VAL_FRACTIONAL_LOG2;
  58         }
  59         return -EINVAL;
  60 }
  61
  62 static int ad5624r_write_raw(struct iio_dev *indio_dev,
  63                                struct iio_chan_spec const *chan,
  64                                int val,
  65                                int val2,
  66                                long mask)
  67 {
  68         struct ad5624r_state *st = iio_priv(indio_dev);
  69
  70         switch (mask) {
  71         case IIO_CHAN_INFO_RAW:
  72                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
  73                         return -EINVAL;
  74
  75                 return ad5624r_spi_write(st->us,
  76                                 AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
  77                                 chan->address, val,
  78                                 chan->scan_type.shift);
  79         default:
  80                 return -EINVAL;
  81         }
  82 }
  83
  84 static const char * const ad5624r_powerdown_modes[] = {
  85         "1kohm_to_gnd",
  86         "100kohm_to_gnd",
  87         "three_state"
  88 };
  89
  90 static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev,
  91         const struct iio_chan_spec *chan)
  92 {
  93         struct ad5624r_state *st = iio_priv(indio_dev);
  94
  95         return st->pwr_down_mode;
  96 }
  97
  98 static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev,
  99         const struct iio_chan_spec *chan, unsigned int mode)
 100 {
 101         struct ad5624r_state *st = iio_priv(indio_dev);
 102
 103         st->pwr_down_mode = mode;
 104
 105         return 0;
 106 }
 107
 108 static const struct iio_enum ad5624r_powerdown_mode_enum = {
 109         .items = ad5624r_powerdown_modes,
 110         .num_items = ARRAY_SIZE(ad5624r_powerdown_modes),
 111         .get = ad5624r_get_powerdown_mode,
 112         .set = ad5624r_set_powerdown_mode,
 113 };
 114
 115 static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev,
 116         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 117 {
 118         struct ad5624r_state *st = iio_priv(indio_dev);
 119
 120         return sysfs_emit(buf, "%d\n",
 121                           !!(st->pwr_down_mask & (1 << chan->channel)));
 122 }
 123
 124 static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev,
 125         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 126         size_t len)
 127 {
 128         bool pwr_down;
 129         int ret;
 130         struct ad5624r_state *st = iio_priv(indio_dev);
 131
 132         ret = kstrtobool(buf, &pwr_down);
 133         if (ret)
 134                 return ret;
 135
 136         if (pwr_down)
 137                 st->pwr_down_mask |= (1 << chan->channel);
 138         else
 139                 st->pwr_down_mask &= ~(1 << chan->channel);
 140
 141         ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
 142                                 (st->pwr_down_mode << 4) |
 143                                 st->pwr_down_mask, 16);
 144
 145         return ret ? ret : len;
 146 }
 147
 148 static const struct iio_info ad5624r_info = {
 149         .write_raw = ad5624r_write_raw,
 150         .read_raw = ad5624r_read_raw,
 151 };
 152
 153 static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
 154         {
 155                 .name = "powerdown",
 156                 .read = ad5624r_read_dac_powerdown,
 157                 .write = ad5624r_write_dac_powerdown,
 158                 .shared = IIO_SEPARATE,
 159         },
 160         IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
 161                  &ad5624r_powerdown_mode_enum),
 162         IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5624r_powerdown_mode_enum),
 163         { },
 164 };
 165
 166 #define AD5624R_CHANNEL(_chan, _bits) { \
 167         .type = IIO_VOLTAGE, \
 168         .indexed = 1, \
 169         .output = 1, \
 170         .channel = (_chan), \
 171         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 172         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 173         .address = (_chan), \
 174         .scan_type = { \
 175                 .sign = 'u', \
 176                 .realbits = (_bits), \
 177                 .storagebits = 16, \
 178                 .shift = 16 - (_bits), \
 179         }, \
 180         .ext_info = ad5624r_ext_info, \
 181 }
 182
 183 #define DECLARE_AD5624R_CHANNELS(_name, _bits) \
 184         const struct iio_chan_spec _name##_channels[] = { \
 185                 AD5624R_CHANNEL(0, _bits), \
 186                 AD5624R_CHANNEL(1, _bits), \
 187                 AD5624R_CHANNEL(2, _bits), \
 188                 AD5624R_CHANNEL(3, _bits), \
 189 }
 190
 191 static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
 192 static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
 193 static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
 194
 195 static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
 196         [ID_AD5624R3] = {
 197                 .channels = ad5624r_channels,
 198                 .int_vref_mv = 1250,
 199         },
 200         [ID_AD5624R5] = {
 201                 .channels = ad5624r_channels,
 202                 .int_vref_mv = 2500,
 203         },
 204         [ID_AD5644R3] = {
 205                 .channels = ad5644r_channels,
 206                 .int_vref_mv = 1250,
 207         },
 208         [ID_AD5644R5] = {
 209                 .channels = ad5644r_channels,
 210                 .int_vref_mv = 2500,
 211         },
 212         [ID_AD5664R3] = {
 213                 .channels = ad5664r_channels,
 214                 .int_vref_mv = 1250,
 215         },
 216         [ID_AD5664R5] = {
 217                 .channels = ad5664r_channels,
 218                 .int_vref_mv = 2500,
 219         },
 220 };
 221
 222 static int ad5624r_probe(struct spi_device *spi)
 223 {
 224         struct ad5624r_state *st;
 225         struct iio_dev *indio_dev;
 226         bool external_vref;
 227         int ret;
 228
 229         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 230         if (!indio_dev)
 231                 return -ENOMEM;
 232         st = iio_priv(indio_dev);
 233         ret = devm_regulator_get_enable_read_voltage(&spi->dev, "vref");
 234         if (ret == -ENODEV)
 235                 /* Backwards compatibility. This naming is not correct */
 236                 ret = devm_regulator_get_enable_read_voltage(&spi->dev, "vcc");
 237         if (ret < 0 && ret != -ENODEV)
 238                 return ret;
 239
 240         external_vref = ret != -ENODEV;
 241         st->vref_mv = external_vref ? ret / 1000 : st->chip_info->int_vref_mv;
 242
 243         st->chip_info =
 244                 &ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
 245
 246         st->us = spi;
 247
 248         indio_dev->name = spi_get_device_id(spi)->name;
 249         indio_dev->info = &ad5624r_info;
 250         indio_dev->modes = INDIO_DIRECT_MODE;
 251         indio_dev->channels = st->chip_info->channels;
 252         indio_dev->num_channels = AD5624R_DAC_CHANNELS;
 253
 254         ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
 255                                 external_vref, 16);
 256         if (ret)
 257                 return ret;
 258
 259         return devm_iio_device_register(&spi->dev, indio_dev);
 260 }
 261
 262 static const struct spi_device_id ad5624r_id[] = {
 263         {"ad5624r3", ID_AD5624R3},
 264         {"ad5644r3", ID_AD5644R3},
 265         {"ad5664r3", ID_AD5664R3},
 266         {"ad5624r5", ID_AD5624R5},
 267         {"ad5644r5", ID_AD5644R5},
 268         {"ad5664r5", ID_AD5664R5},
 269         {}
 270 };
 271 MODULE_DEVICE_TABLE(spi, ad5624r_id);
 272
 273 static struct spi_driver ad5624r_driver = {
 274         .driver = {
 275                    .name = "ad5624r",
 276                    },
 277         .probe = ad5624r_probe,
 278         .id_table = ad5624r_id,
 279 };
 280 module_spi_driver(ad5624r_driver);
 281
 282 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 283 MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
 284 MODULE_LICENSE("GPL v2");