1 // SPDX-License-Identifier: GPL-2.0 2 /* TI ADS124S0X chip family driver 3 * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/ 4 */ 5 6 #include <linux/err.h> 7 #include <linux/delay.h> 8 #include <linux/device.h> 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/of.h> 12 #include <linux/of_gpio.h> 13 #include <linux/slab.h> 14 #include <linux/sysfs.h> 15 16 #include <linux/gpio/consumer.h> 17 #include <linux/spi/spi.h> 18 19 #include <linux/iio/iio.h> 20 #include <linux/iio/buffer.h> 21 #include <linux/iio/trigger_consumer.h> 22 #include <linux/iio/triggered_buffer.h> 23 #include <linux/iio/sysfs.h> 24 25 /* Commands */ 26 #define ADS124S08_CMD_NOP 0x00 27 #define ADS124S08_CMD_WAKEUP 0x02 28 #define ADS124S08_CMD_PWRDWN 0x04 29 #define ADS124S08_CMD_RESET 0x06 30 #define ADS124S08_CMD_START 0x08 31 #define ADS124S08_CMD_STOP 0x0a 32 #define ADS124S08_CMD_SYOCAL 0x16 33 #define ADS124S08_CMD_SYGCAL 0x17 34 #define ADS124S08_CMD_SFOCAL 0x19 35 #define ADS124S08_CMD_RDATA 0x12 36 #define ADS124S08_CMD_RREG 0x20 37 #define ADS124S08_CMD_WREG 0x40 38 39 /* Registers */ 40 #define ADS124S08_ID_REG 0x00 41 #define ADS124S08_STATUS 0x01 42 #define ADS124S08_INPUT_MUX 0x02 43 #define ADS124S08_PGA 0x03 44 #define ADS124S08_DATA_RATE 0x04 45 #define ADS124S08_REF 0x05 46 #define ADS124S08_IDACMAG 0x06 47 #define ADS124S08_IDACMUX 0x07 48 #define ADS124S08_VBIAS 0x08 49 #define ADS124S08_SYS 0x09 50 #define ADS124S08_OFCAL0 0x0a 51 #define ADS124S08_OFCAL1 0x0b 52 #define ADS124S08_OFCAL2 0x0c 53 #define ADS124S08_FSCAL0 0x0d 54 #define ADS124S08_FSCAL1 0x0e 55 #define ADS124S08_FSCAL2 0x0f 56 #define ADS124S08_GPIODAT 0x10 57 #define ADS124S08_GPIOCON 0x11 58 59 /* ADS124S0x common channels */ 60 #define ADS124S08_AIN0 0x00 61 #define ADS124S08_AIN1 0x01 62 #define ADS124S08_AIN2 0x02 63 #define ADS124S08_AIN3 0x03 64 #define ADS124S08_AIN4 0x04 65 #define ADS124S08_AIN5 0x05 66 #define ADS124S08_AINCOM 0x0c 67 /* ADS124S08 only channels */ 68 #define ADS124S08_AIN6 0x06 69 #define ADS124S08_AIN7 0x07 70 #define ADS124S08_AIN8 0x08 71 #define ADS124S08_AIN9 0x09 72 #define ADS124S08_AIN10 0x0a 73 #define ADS124S08_AIN11 0x0b 74 #define ADS124S08_MAX_CHANNELS 12 75 76 #define ADS124S08_POS_MUX_SHIFT 0x04 77 #define ADS124S08_INT_REF 0x09 78 79 #define ADS124S08_START_REG_MASK 0x1f 80 #define ADS124S08_NUM_BYTES_MASK 0x1f 81 82 #define ADS124S08_START_CONV 0x01 83 #define ADS124S08_STOP_CONV 0x00 84 85 enum ads124s_id { 86 ADS124S08_ID, 87 ADS124S06_ID, 88 }; 89 90 struct ads124s_chip_info { 91 const struct iio_chan_spec *channels; 92 unsigned int num_channels; 93 }; 94 95 struct ads124s_private { 96 const struct ads124s_chip_info *chip_info; 97 struct gpio_desc *reset_gpio; 98 struct spi_device *spi; 99 struct mutex lock; 100 u8 data[5] ____cacheline_aligned; 101 }; 102 103 #define ADS124S08_CHAN(index) \ 104 { \ 105 .type = IIO_VOLTAGE, \ 106 .indexed = 1, \ 107 .channel = index, \ 108 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 109 .scan_index = index, \ 110 .scan_type = { \ 111 .sign = 'u', \ 112 .realbits = 32, \ 113 .storagebits = 32, \ 114 }, \ 115 } 116 117 static const struct iio_chan_spec ads124s06_channels[] = { 118 ADS124S08_CHAN(0), 119 ADS124S08_CHAN(1), 120 ADS124S08_CHAN(2), 121 ADS124S08_CHAN(3), 122 ADS124S08_CHAN(4), 123 ADS124S08_CHAN(5), 124 }; 125 126 static const struct iio_chan_spec ads124s08_channels[] = { 127 ADS124S08_CHAN(0), 128 ADS124S08_CHAN(1), 129 ADS124S08_CHAN(2), 130 ADS124S08_CHAN(3), 131 ADS124S08_CHAN(4), 132 ADS124S08_CHAN(5), 133 ADS124S08_CHAN(6), 134 ADS124S08_CHAN(7), 135 ADS124S08_CHAN(8), 136 ADS124S08_CHAN(9), 137 ADS124S08_CHAN(10), 138 ADS124S08_CHAN(11), 139 }; 140 141 static const struct ads124s_chip_info ads124s_chip_info_tbl[] = { 142 [ADS124S08_ID] = { 143 .channels = ads124s08_channels, 144 .num_channels = ARRAY_SIZE(ads124s08_channels), 145 }, 146 [ADS124S06_ID] = { 147 .channels = ads124s06_channels, 148 .num_channels = ARRAY_SIZE(ads124s06_channels), 149 }, 150 }; 151 152 static int ads124s_write_cmd(struct iio_dev *indio_dev, u8 command) 153 { 154 struct ads124s_private *priv = iio_priv(indio_dev); 155 156 priv->data[0] = command; 157 158 return spi_write(priv->spi, &priv->data[0], 1); 159 } 160 161 static int ads124s_write_reg(struct iio_dev *indio_dev, u8 reg, u8 data) 162 { 163 struct ads124s_private *priv = iio_priv(indio_dev); 164 165 priv->data[0] = ADS124S08_CMD_WREG | reg; 166 priv->data[1] = 0x0; 167 priv->data[2] = data; 168 169 return spi_write(priv->spi, &priv->data[0], 3); 170 } 171 172 static int ads124s_reset(struct iio_dev *indio_dev) 173 { 174 struct ads124s_private *priv = iio_priv(indio_dev); 175 176 if (priv->reset_gpio) { 177 gpiod_set_value(priv->reset_gpio, 0); 178 udelay(200); 179 gpiod_set_value(priv->reset_gpio, 1); 180 } else { 181 return ads124s_write_cmd(indio_dev, ADS124S08_CMD_RESET); 182 } 183 184 return 0; 185 }; 186 187 static int ads124s_read(struct iio_dev *indio_dev, unsigned int chan) 188 { 189 struct ads124s_private *priv = iio_priv(indio_dev); 190 int ret; 191 u32 tmp; 192 struct spi_transfer t[] = { 193 { 194 .tx_buf = &priv->data[0], 195 .len = 4, 196 .cs_change = 1, 197 }, { 198 .tx_buf = &priv->data[1], 199 .rx_buf = &priv->data[1], 200 .len = 4, 201 }, 202 }; 203 204 priv->data[0] = ADS124S08_CMD_RDATA; 205 memset(&priv->data[1], ADS124S08_CMD_NOP, sizeof(priv->data)); 206 207 ret = spi_sync_transfer(priv->spi, t, ARRAY_SIZE(t)); 208 if (ret < 0) 209 return ret; 210 211 tmp = priv->data[2] << 16 | priv->data[3] << 8 | priv->data[4]; 212 213 return tmp; 214 } 215 216 static int ads124s_read_raw(struct iio_dev *indio_dev, 217 struct iio_chan_spec const *chan, 218 int *val, int *val2, long m) 219 { 220 struct ads124s_private *priv = iio_priv(indio_dev); 221 int ret; 222 223 mutex_lock(&priv->lock); 224 switch (m) { 225 case IIO_CHAN_INFO_RAW: 226 ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX, 227 chan->channel); 228 if (ret) { 229 dev_err(&priv->spi->dev, "Set ADC CH failed\n"); 230 goto out; 231 } 232 233 ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV); 234 if (ret) { 235 dev_err(&priv->spi->dev, "Start conversions failed\n"); 236 goto out; 237 } 238 239 ret = ads124s_read(indio_dev, chan->channel); 240 if (ret < 0) { 241 dev_err(&priv->spi->dev, "Read ADC failed\n"); 242 goto out; 243 } 244 245 *val = ret; 246 247 ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV); 248 if (ret) { 249 dev_err(&priv->spi->dev, "Stop conversions failed\n"); 250 goto out; 251 } 252 253 ret = IIO_VAL_INT; 254 break; 255 default: 256 ret = -EINVAL; 257 break; 258 } 259 out: 260 mutex_unlock(&priv->lock); 261 return ret; 262 } 263 264 static const struct iio_info ads124s_info = { 265 .read_raw = &ads124s_read_raw, 266 }; 267 268 static irqreturn_t ads124s_trigger_handler(int irq, void *p) 269 { 270 struct iio_poll_func *pf = p; 271 struct iio_dev *indio_dev = pf->indio_dev; 272 struct ads124s_private *priv = iio_priv(indio_dev); 273 u32 buffer[ADS124S08_MAX_CHANNELS + sizeof(s64)/sizeof(u16)]; 274 int scan_index, j = 0; 275 int ret; 276 277 for_each_set_bit(scan_index, indio_dev->active_scan_mask, 278 indio_dev->masklength) { 279 ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX, 280 scan_index); 281 if (ret) 282 dev_err(&priv->spi->dev, "Set ADC CH failed\n"); 283 284 ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV); 285 if (ret) 286 dev_err(&priv->spi->dev, "Start ADC conversions failed\n"); 287 288 buffer[j] = ads124s_read(indio_dev, scan_index); 289 ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV); 290 if (ret) 291 dev_err(&priv->spi->dev, "Stop ADC conversions failed\n"); 292 293 j++; 294 } 295 296 iio_push_to_buffers_with_timestamp(indio_dev, buffer, 297 pf->timestamp); 298 299 iio_trigger_notify_done(indio_dev->trig); 300 301 return IRQ_HANDLED; 302 } 303 304 static int ads124s_probe(struct spi_device *spi) 305 { 306 struct ads124s_private *ads124s_priv; 307 struct iio_dev *indio_dev; 308 const struct spi_device_id *spi_id = spi_get_device_id(spi); 309 int ret; 310 311 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ads124s_priv)); 312 if (indio_dev == NULL) 313 return -ENOMEM; 314 315 ads124s_priv = iio_priv(indio_dev); 316 317 ads124s_priv->reset_gpio = devm_gpiod_get_optional(&spi->dev, 318 "reset", GPIOD_OUT_LOW); 319 if (IS_ERR(ads124s_priv->reset_gpio)) 320 dev_info(&spi->dev, "Reset GPIO not defined\n"); 321 322 ads124s_priv->chip_info = &ads124s_chip_info_tbl[spi_id->driver_data]; 323 324 spi_set_drvdata(spi, indio_dev); 325 326 ads124s_priv->spi = spi; 327 328 indio_dev->name = spi_id->name; 329 indio_dev->dev.parent = &spi->dev; 330 indio_dev->dev.of_node = spi->dev.of_node; 331 indio_dev->modes = INDIO_DIRECT_MODE; 332 indio_dev->channels = ads124s_priv->chip_info->channels; 333 indio_dev->num_channels = ads124s_priv->chip_info->num_channels; 334 indio_dev->info = &ads124s_info; 335 336 mutex_init(&ads124s_priv->lock); 337 338 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL, 339 ads124s_trigger_handler, NULL); 340 if (ret) { 341 dev_err(&spi->dev, "iio triggered buffer setup failed\n"); 342 return ret; 343 } 344 345 ads124s_reset(indio_dev); 346 347 return devm_iio_device_register(&spi->dev, indio_dev); 348 } 349 350 static const struct spi_device_id ads124s_id[] = { 351 { "ads124s06", ADS124S06_ID }, 352 { "ads124s08", ADS124S08_ID }, 353 { } 354 }; 355 MODULE_DEVICE_TABLE(spi, ads124s_id); 356 357 static const struct of_device_id ads124s_of_table[] = { 358 { .compatible = "ti,ads124s06" }, 359 { .compatible = "ti,ads124s08" }, 360 { }, 361 }; 362 MODULE_DEVICE_TABLE(of, ads124s_of_table); 363 364 static struct spi_driver ads124s_driver = { 365 .driver = { 366 .name = "ads124s08", 367 .of_match_table = ads124s_of_table, 368 }, 369 .probe = ads124s_probe, 370 .id_table = ads124s_id, 371 }; 372 module_spi_driver(ads124s_driver); 373 374 MODULE_AUTHOR("Dan Murphy <dmuprhy@ti.com>"); 375 MODULE_DESCRIPTION("TI TI_ADS12S0X ADC"); 376 MODULE_LICENSE("GPL v2"); 377