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"); 365