drivers/iio/adc/ad7606_spi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * AD7606 SPI ADC driver
   4  *
   5  * Copyright 2011 Analog Devices Inc.
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/spi/spi.h>
  10 #include <linux/types.h>
  11 #include <linux/err.h>
  12
  13 #include <linux/iio/iio.h>
  14 #include "ad7606.h"
  15
  16 #define MAX_SPI_FREQ_HZ         23500000        /* VDRIVE above 4.75 V */
  17
  18 #define AD7616_CONFIGURATION_REGISTER   0x02
  19 #define AD7616_OS_MASK                  GENMASK(4, 2)
  20 #define AD7616_BURST_MODE               BIT(6)
  21 #define AD7616_SEQEN_MODE               BIT(5)
  22 #define AD7616_RANGE_CH_A_ADDR_OFF      0x04
  23 #define AD7616_RANGE_CH_B_ADDR_OFF      0x06
  24 /*
  25  * Range of channels from a group are stored in 2 registers.
  26  * 0, 1, 2, 3 in a register followed by 4, 5, 6, 7 in second register.
  27  * For channels from second group(8-15) the order is the same, only with
  28  * an offset of 2 for register address.
  29  */
  30 #define AD7616_RANGE_CH_ADDR(ch)        ((ch) >> 2)
  31 /* The range of the channel is stored in 2 bits */
  32 #define AD7616_RANGE_CH_MSK(ch)         (0b11 << (((ch) & 0b11) * 2))
  33 #define AD7616_RANGE_CH_MODE(ch, mode)  ((mode) << ((((ch) & 0b11)) * 2))
  34
  35 #define AD7606_CONFIGURATION_REGISTER   0x02
  36 #define AD7606_SINGLE_DOUT              0x00
  37
  38 /*
  39  * Range for AD7606B channels are stored in registers starting with address 0x3.
  40  * Each register stores range for 2 channels(4 bits per channel).
  41  */
  42 #define AD7606_RANGE_CH_MSK(ch)         (GENMASK(3, 0) << (4 * ((ch) & 0x1)))
  43 #define AD7606_RANGE_CH_MODE(ch, mode)  \
  44         ((GENMASK(3, 0) & mode) << (4 * ((ch) & 0x1)))
  45 #define AD7606_RANGE_CH_ADDR(ch)        (0x03 + ((ch) >> 1))
  46 #define AD7606_OS_MODE                  0x08
  47
  48 static const struct iio_chan_spec ad7616_sw_channels[] = {
  49         IIO_CHAN_SOFT_TIMESTAMP(16),
  50         AD7616_CHANNEL(0),
  51         AD7616_CHANNEL(1),
  52         AD7616_CHANNEL(2),
  53         AD7616_CHANNEL(3),
  54         AD7616_CHANNEL(4),
  55         AD7616_CHANNEL(5),
  56         AD7616_CHANNEL(6),
  57         AD7616_CHANNEL(7),
  58         AD7616_CHANNEL(8),
  59         AD7616_CHANNEL(9),
  60         AD7616_CHANNEL(10),
  61         AD7616_CHANNEL(11),
  62         AD7616_CHANNEL(12),
  63         AD7616_CHANNEL(13),
  64         AD7616_CHANNEL(14),
  65         AD7616_CHANNEL(15),
  66 };
  67
  68 static const struct iio_chan_spec ad7606b_sw_channels[] = {
  69         IIO_CHAN_SOFT_TIMESTAMP(8),
  70         AD7616_CHANNEL(0),
  71         AD7616_CHANNEL(1),
  72         AD7616_CHANNEL(2),
  73         AD7616_CHANNEL(3),
  74         AD7616_CHANNEL(4),
  75         AD7616_CHANNEL(5),
  76         AD7616_CHANNEL(6),
  77         AD7616_CHANNEL(7),
  78 };
  79
  80 static const unsigned int ad7606B_oversampling_avail[9] = {
  81         1, 2, 4, 8, 16, 32, 64, 128, 256
  82 };
  83
  84 static u16 ad7616_spi_rd_wr_cmd(int addr, char isWriteOp)
  85 {
  86         /*
  87          * The address of register consist of one w/r bit
  88          * 6 bits of address followed by one reserved bit.
  89          */
  90         return ((addr & 0x7F) << 1) | ((isWriteOp & 0x1) << 7);
  91 }
  92
  93 static u16 ad7606B_spi_rd_wr_cmd(int addr, char is_write_op)
  94 {
  95         /*
  96          * The address of register consists of one bit which
  97          * specifies a read command placed in bit 6, followed by
  98          * 6 bits of address.
  99          */
 100         return (addr & 0x3F) | (((~is_write_op) & 0x1) << 6);
 101 }
 102
 103 static int ad7606_spi_read_block(struct device *dev,
 104                                  int count, void *buf)
 105 {
 106         struct spi_device *spi = to_spi_device(dev);
 107         int i, ret;
 108         unsigned short *data = buf;
 109         __be16 *bdata = buf;
 110
 111         ret = spi_read(spi, buf, count * 2);
 112         if (ret < 0) {
 113                 dev_err(&spi->dev, "SPI read error\n");
 114                 return ret;
 115         }
 116
 117         for (i = 0; i < count; i++)
 118                 data[i] = be16_to_cpu(bdata[i]);
 119
 120         return 0;
 121 }
 122
 123 static int ad7606_spi_reg_read(struct ad7606_state *st, unsigned int addr)
 124 {
 125         struct spi_device *spi = to_spi_device(st->dev);
 126         struct spi_transfer t[] = {
 127                 {
 128                         .tx_buf = &st->d16[0],
 129                         .len = 2,
 130                         .cs_change = 0,
 131                 }, {
 132                         .rx_buf = &st->d16[1],
 133                         .len = 2,
 134                 },
 135         };
 136         int ret;
 137
 138         st->d16[0] = cpu_to_be16(st->bops->rd_wr_cmd(addr, 0) << 8);
 139
 140         ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t));
 141         if (ret < 0)
 142                 return ret;
 143
 144         return be16_to_cpu(st->d16[1]);
 145 }
 146
 147 static int ad7606_spi_reg_write(struct ad7606_state *st,
 148                                 unsigned int addr,
 149                                 unsigned int val)
 150 {
 151         struct spi_device *spi = to_spi_device(st->dev);
 152
 153         st->d16[0] = cpu_to_be16((st->bops->rd_wr_cmd(addr, 1) << 8) |
 154                                   (val & 0x1FF));
 155
 156         return spi_write(spi, &st->d16[0], sizeof(st->d16[0]));
 157 }
 158
 159 static int ad7606_spi_write_mask(struct ad7606_state *st,
 160                                  unsigned int addr,
 161                                  unsigned long mask,
 162                                  unsigned int val)
 163 {
 164         int readval;
 165
 166         readval = st->bops->reg_read(st, addr);
 167         if (readval < 0)
 168                 return readval;
 169
 170         readval &= ~mask;
 171         readval |= val;
 172
 173         return st->bops->reg_write(st, addr, readval);
 174 }
 175
 176 static int ad7616_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
 177 {
 178         struct ad7606_state *st = iio_priv(indio_dev);
 179         unsigned int ch_addr, mode, ch_index;
 180
 181
 182         /*
 183          * Ad7616 has 16 channels divided in group A and group B.
 184          * The range of channels from A are stored in registers with address 4
 185          * while channels from B are stored in register with address 6.
 186          * The last bit from channels determines if it is from group A or B
 187          * because the order of channels in iio is 0A, 0B, 1A, 1B...
 188          */
 189         ch_index = ch >> 1;
 190
 191         ch_addr = AD7616_RANGE_CH_ADDR(ch_index);
 192
 193         if ((ch & 0x1) == 0) /* channel A */
 194                 ch_addr += AD7616_RANGE_CH_A_ADDR_OFF;
 195         else    /* channel B */
 196                 ch_addr += AD7616_RANGE_CH_B_ADDR_OFF;
 197
 198         /* 0b01 for 2.5v, 0b10 for 5v and 0b11 for 10v */
 199         mode = AD7616_RANGE_CH_MODE(ch_index, ((val + 1) & 0b11));
 200         return st->bops->write_mask(st, ch_addr, AD7616_RANGE_CH_MSK(ch_index),
 201                                      mode);
 202 }
 203
 204 static int ad7616_write_os_sw(struct iio_dev *indio_dev, int val)
 205 {
 206         struct ad7606_state *st = iio_priv(indio_dev);
 207
 208         return st->bops->write_mask(st, AD7616_CONFIGURATION_REGISTER,
 209                                      AD7616_OS_MASK, val << 2);
 210 }
 211
 212 static int ad7606_write_scale_sw(struct iio_dev *indio_dev, int ch, int val)
 213 {
 214         struct ad7606_state *st = iio_priv(indio_dev);
 215
 216         return ad7606_spi_write_mask(st,
 217                                      AD7606_RANGE_CH_ADDR(ch),
 218                                      AD7606_RANGE_CH_MSK(ch),
 219                                      AD7606_RANGE_CH_MODE(ch, val));
 220 }
 221
 222 static int ad7606_write_os_sw(struct iio_dev *indio_dev, int val)
 223 {
 224         struct ad7606_state *st = iio_priv(indio_dev);
 225
 226         return ad7606_spi_reg_write(st, AD7606_OS_MODE, val);
 227 }
 228
 229 static int ad7616_sw_mode_config(struct iio_dev *indio_dev)
 230 {
 231         struct ad7606_state *st = iio_priv(indio_dev);
 232
 233         /*
 234          * Scale can be configured individually for each channel
 235          * in software mode.
 236          */
 237         indio_dev->channels = ad7616_sw_channels;
 238
 239         st->write_scale = ad7616_write_scale_sw;
 240         st->write_os = &ad7616_write_os_sw;
 241
 242         /* Activate Burst mode and SEQEN MODE */
 243         return st->bops->write_mask(st,
 244                               AD7616_CONFIGURATION_REGISTER,
 245                               AD7616_BURST_MODE | AD7616_SEQEN_MODE,
 246                               AD7616_BURST_MODE | AD7616_SEQEN_MODE);
 247 }
 248
 249 static int ad7606B_sw_mode_config(struct iio_dev *indio_dev)
 250 {
 251         struct ad7606_state *st = iio_priv(indio_dev);
 252         unsigned long os[3] = {1};
 253
 254         /*
 255          * Software mode is enabled when all three oversampling
 256          * pins are set to high. If oversampling gpios are defined
 257          * in the device tree, then they need to be set to high,
 258          * otherwise, they must be hardwired to VDD
 259          */
 260         if (st->gpio_os) {
 261                 gpiod_set_array_value(ARRAY_SIZE(os),
 262                                       st->gpio_os->desc, st->gpio_os->info, os);
 263         }
 264         /* OS of 128 and 256 are available only in software mode */
 265         st->oversampling_avail = ad7606B_oversampling_avail;
 266         st->num_os_ratios = ARRAY_SIZE(ad7606B_oversampling_avail);
 267
 268         st->write_scale = ad7606_write_scale_sw;
 269         st->write_os = &ad7606_write_os_sw;
 270
 271         /* Configure device spi to output on a single channel */
 272         st->bops->reg_write(st,
 273                             AD7606_CONFIGURATION_REGISTER,
 274                             AD7606_SINGLE_DOUT);
 275
 276         /*
 277          * Scale can be configured individually for each channel
 278          * in software mode.
 279          */
 280         indio_dev->channels = ad7606b_sw_channels;
 281
 282         return 0;
 283 }
 284
 285 static const struct ad7606_bus_ops ad7606_spi_bops = {
 286         .read_block = ad7606_spi_read_block,
 287 };
 288
 289 static const struct ad7606_bus_ops ad7616_spi_bops = {
 290         .read_block = ad7606_spi_read_block,
 291         .reg_read = ad7606_spi_reg_read,
 292         .reg_write = ad7606_spi_reg_write,
 293         .write_mask = ad7606_spi_write_mask,
 294         .rd_wr_cmd = ad7616_spi_rd_wr_cmd,
 295         .sw_mode_config = ad7616_sw_mode_config,
 296 };
 297
 298 static const struct ad7606_bus_ops ad7606B_spi_bops = {
 299         .read_block = ad7606_spi_read_block,
 300         .reg_read = ad7606_spi_reg_read,
 301         .reg_write = ad7606_spi_reg_write,
 302         .write_mask = ad7606_spi_write_mask,
 303         .rd_wr_cmd = ad7606B_spi_rd_wr_cmd,
 304         .sw_mode_config = ad7606B_sw_mode_config,
 305 };
 306
 307 static int ad7606_spi_probe(struct spi_device *spi)
 308 {
 309         const struct spi_device_id *id = spi_get_device_id(spi);
 310         const struct ad7606_bus_ops *bops;
 311
 312         switch (id->driver_data) {
 313         case ID_AD7616:
 314                 bops = &ad7616_spi_bops;
 315                 break;
 316         case ID_AD7606B:
 317                 bops = &ad7606B_spi_bops;
 318                 break;
 319         default:
 320                 bops = &ad7606_spi_bops;
 321                 break;
 322         }
 323
 324         return ad7606_probe(&spi->dev, spi->irq, NULL,
 325                             id->name, id->driver_data,
 326                             bops);
 327 }
 328
 329 static const struct spi_device_id ad7606_id_table[] = {
 330         { "ad7605-4", ID_AD7605_4 },
 331         { "ad7606-4", ID_AD7606_4 },
 332         { "ad7606-6", ID_AD7606_6 },
 333         { "ad7606-8", ID_AD7606_8 },
 334         { "ad7606b",  ID_AD7606B },
 335         { "ad7616",   ID_AD7616 },
 336         {}
 337 };
 338 MODULE_DEVICE_TABLE(spi, ad7606_id_table);
 339
 340 static const struct of_device_id ad7606_of_match[] = {
 341         { .compatible = "adi,ad7605-4" },
 342         { .compatible = "adi,ad7606-4" },
 343         { .compatible = "adi,ad7606-6" },
 344         { .compatible = "adi,ad7606-8" },
 345         { .compatible = "adi,ad7606b" },
 346         { .compatible = "adi,ad7616" },
 347         { },
 348 };
 349 MODULE_DEVICE_TABLE(of, ad7606_of_match);
 350
 351 static struct spi_driver ad7606_driver = {
 352         .driver = {
 353                 .name = "ad7606",
 354                 .of_match_table = ad7606_of_match,
 355                 .pm = AD7606_PM_OPS,
 356         },
 357         .probe = ad7606_spi_probe,
 358         .id_table = ad7606_id_table,
 359 };
 360 module_spi_driver(ad7606_driver);
 361
 362 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 363 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
 364 MODULE_LICENSE("GPL v2");