Gregor Boirie | 03b262f | 2016-09-13 14:23:14 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Murata ZPA2326 pressure and temperature sensor IIO driver |
| 3 | * |
| 4 | * Copyright (c) 2016 Parrot S.A. |
| 5 | * |
| 6 | * Author: Gregor Boirie <gregor.boirie@parrot.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify it |
| 9 | * under the terms of the GNU General Public License version 2 as published by |
| 10 | * the Free Software Foundation. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 15 | * more details. |
| 16 | */ |
| 17 | |
| 18 | /** |
| 19 | * DOC: ZPA2326 theory of operations |
| 20 | * |
| 21 | * This driver supports %INDIO_DIRECT_MODE and %INDIO_BUFFER_TRIGGERED IIO |
| 22 | * modes. |
| 23 | * A internal hardware trigger is also implemented to dispatch registered IIO |
| 24 | * trigger consumers upon "sample ready" interrupts. |
| 25 | * |
| 26 | * ZPA2326 hardware supports 2 sampling mode: one shot and continuous. |
| 27 | * |
| 28 | * A complete one shot sampling cycle gets device out of low power mode, |
| 29 | * performs pressure and temperature measurements, then automatically switches |
| 30 | * back to low power mode. It is meant for on demand sampling with optimal power |
| 31 | * saving at the cost of lower sampling rate and higher software overhead. |
| 32 | * This is a natural candidate for IIO read_raw hook implementation |
| 33 | * (%INDIO_DIRECT_MODE). It is also used for triggered buffering support to |
| 34 | * ensure explicit synchronization with external trigger events |
| 35 | * (%INDIO_BUFFER_TRIGGERED). |
| 36 | * |
| 37 | * The continuous mode works according to a periodic hardware measurement |
| 38 | * process continuously pushing samples into an internal hardware FIFO (for |
| 39 | * pressure samples only). Measurement cycle completion may be signaled by a |
| 40 | * "sample ready" interrupt. |
| 41 | * Typical software sequence of operations : |
| 42 | * - get device out of low power mode, |
| 43 | * - setup hardware sampling period, |
| 44 | * - at end of period, upon data ready interrupt: pop pressure samples out of |
| 45 | * hardware FIFO and fetch temperature sample |
| 46 | * - when no longer needed, stop sampling process by putting device into |
| 47 | * low power mode. |
| 48 | * This mode is used to implement %INDIO_BUFFER_TRIGGERED mode if device tree |
| 49 | * declares a valid interrupt line. In this case, the internal hardware trigger |
| 50 | * drives acquisition. |
| 51 | * |
| 52 | * Note that hardware sampling frequency is taken into account only when |
| 53 | * internal hardware trigger is attached as the highest sampling rate seems to |
| 54 | * be the most energy efficient. |
| 55 | * |
| 56 | * TODO: |
| 57 | * preset pressure threshold crossing / IIO events ; |
| 58 | * differential pressure sampling ; |
| 59 | * hardware samples averaging. |
| 60 | */ |
| 61 | |
| 62 | #include <linux/module.h> |
| 63 | #include <linux/kernel.h> |
| 64 | #include <linux/delay.h> |
| 65 | #include <linux/interrupt.h> |
| 66 | #include <linux/regulator/consumer.h> |
| 67 | #include <linux/pm_runtime.h> |
| 68 | #include <linux/regmap.h> |
| 69 | #include <linux/iio/iio.h> |
| 70 | #include <linux/iio/sysfs.h> |
| 71 | #include <linux/iio/buffer.h> |
| 72 | #include <linux/iio/trigger.h> |
| 73 | #include <linux/iio/trigger_consumer.h> |
| 74 | #include <linux/iio/triggered_buffer.h> |
| 75 | #include "zpa2326.h" |
| 76 | |
| 77 | /* 200 ms should be enough for the longest conversion time in one-shot mode. */ |
| 78 | #define ZPA2326_CONVERSION_JIFFIES (HZ / 5) |
| 79 | |
| 80 | /* There should be a 1 ms delay (Tpup) after getting out of reset. */ |
| 81 | #define ZPA2326_TPUP_USEC_MIN (1000) |
| 82 | #define ZPA2326_TPUP_USEC_MAX (2000) |
| 83 | |
| 84 | /** |
| 85 | * struct zpa2326_frequency - Hardware sampling frequency descriptor |
| 86 | * @hz : Frequency in Hertz. |
| 87 | * @odr: Output Data Rate word as expected by %ZPA2326_CTRL_REG3_REG. |
| 88 | */ |
| 89 | struct zpa2326_frequency { |
| 90 | int hz; |
| 91 | u16 odr; |
| 92 | }; |
| 93 | |
| 94 | /* |
| 95 | * Keep these in strict ascending order: last array entry is expected to |
| 96 | * correspond to the highest sampling frequency. |
| 97 | */ |
| 98 | static const struct zpa2326_frequency zpa2326_sampling_frequencies[] = { |
| 99 | { .hz = 1, .odr = 1 << ZPA2326_CTRL_REG3_ODR_SHIFT }, |
| 100 | { .hz = 5, .odr = 5 << ZPA2326_CTRL_REG3_ODR_SHIFT }, |
| 101 | { .hz = 11, .odr = 6 << ZPA2326_CTRL_REG3_ODR_SHIFT }, |
| 102 | { .hz = 23, .odr = 7 << ZPA2326_CTRL_REG3_ODR_SHIFT }, |
| 103 | }; |
| 104 | |
| 105 | /* Return the highest hardware sampling frequency available. */ |
| 106 | static const struct zpa2326_frequency *zpa2326_highest_frequency(void) |
| 107 | { |
| 108 | return &zpa2326_sampling_frequencies[ |
| 109 | ARRAY_SIZE(zpa2326_sampling_frequencies) - 1]; |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * struct zpa_private - Per-device internal private state |
| 114 | * @timestamp: Buffered samples ready datum. |
| 115 | * @regmap: Underlying I2C / SPI bus adapter used to abstract slave register |
| 116 | * accesses. |
| 117 | * @result: Allows sampling logic to get completion status of operations |
| 118 | * that interrupt handlers perform asynchronously. |
| 119 | * @data_ready: Interrupt handler uses this to wake user context up at sampling |
| 120 | * operation completion. |
| 121 | * @trigger: Optional hardware / interrupt driven trigger used to notify |
| 122 | * external devices a new sample is ready. |
| 123 | * @waken: Flag indicating whether or not device has just been powered on. |
| 124 | * @irq: Optional interrupt line: negative or zero if not declared into |
| 125 | * DT, in which case sampling logic keeps polling status register |
| 126 | * to detect completion. |
| 127 | * @frequency: Current hardware sampling frequency. |
| 128 | * @vref: Power / voltage reference. |
| 129 | * @vdd: Power supply. |
| 130 | */ |
| 131 | struct zpa2326_private { |
| 132 | s64 timestamp; |
| 133 | struct regmap *regmap; |
| 134 | int result; |
| 135 | struct completion data_ready; |
| 136 | struct iio_trigger *trigger; |
| 137 | bool waken; |
| 138 | int irq; |
| 139 | const struct zpa2326_frequency *frequency; |
| 140 | struct regulator *vref; |
| 141 | struct regulator *vdd; |
| 142 | }; |
| 143 | |
| 144 | #define zpa2326_err(_idev, _format, _arg...) \ |
| 145 | dev_err(_idev->dev.parent, _format, ##_arg) |
| 146 | |
| 147 | #define zpa2326_warn(_idev, _format, _arg...) \ |
| 148 | dev_warn(_idev->dev.parent, _format, ##_arg) |
| 149 | |
| 150 | #ifdef DEBUG |
| 151 | #define zpa2326_dbg(_idev, _format, _arg...) \ |
| 152 | dev_dbg(_idev->dev.parent, _format, ##_arg) |
| 153 | #else |
| 154 | #define zpa2326_dbg(_idev, _format, _arg...) |
| 155 | #endif |
| 156 | |
| 157 | bool zpa2326_isreg_writeable(struct device *dev, unsigned int reg) |
| 158 | { |
| 159 | switch (reg) { |
| 160 | case ZPA2326_REF_P_XL_REG: |
| 161 | case ZPA2326_REF_P_L_REG: |
| 162 | case ZPA2326_REF_P_H_REG: |
| 163 | case ZPA2326_RES_CONF_REG: |
| 164 | case ZPA2326_CTRL_REG0_REG: |
| 165 | case ZPA2326_CTRL_REG1_REG: |
| 166 | case ZPA2326_CTRL_REG2_REG: |
| 167 | case ZPA2326_CTRL_REG3_REG: |
| 168 | case ZPA2326_THS_P_LOW_REG: |
| 169 | case ZPA2326_THS_P_HIGH_REG: |
| 170 | return true; |
| 171 | |
| 172 | default: |
| 173 | return false; |
| 174 | } |
| 175 | } |
| 176 | EXPORT_SYMBOL_GPL(zpa2326_isreg_writeable); |
| 177 | |
| 178 | bool zpa2326_isreg_readable(struct device *dev, unsigned int reg) |
| 179 | { |
| 180 | switch (reg) { |
| 181 | case ZPA2326_REF_P_XL_REG: |
| 182 | case ZPA2326_REF_P_L_REG: |
| 183 | case ZPA2326_REF_P_H_REG: |
| 184 | case ZPA2326_DEVICE_ID_REG: |
| 185 | case ZPA2326_RES_CONF_REG: |
| 186 | case ZPA2326_CTRL_REG0_REG: |
| 187 | case ZPA2326_CTRL_REG1_REG: |
| 188 | case ZPA2326_CTRL_REG2_REG: |
| 189 | case ZPA2326_CTRL_REG3_REG: |
| 190 | case ZPA2326_INT_SOURCE_REG: |
| 191 | case ZPA2326_THS_P_LOW_REG: |
| 192 | case ZPA2326_THS_P_HIGH_REG: |
| 193 | case ZPA2326_STATUS_REG: |
| 194 | case ZPA2326_PRESS_OUT_XL_REG: |
| 195 | case ZPA2326_PRESS_OUT_L_REG: |
| 196 | case ZPA2326_PRESS_OUT_H_REG: |
| 197 | case ZPA2326_TEMP_OUT_L_REG: |
| 198 | case ZPA2326_TEMP_OUT_H_REG: |
| 199 | return true; |
| 200 | |
| 201 | default: |
| 202 | return false; |
| 203 | } |
| 204 | } |
| 205 | EXPORT_SYMBOL_GPL(zpa2326_isreg_readable); |
| 206 | |
| 207 | bool zpa2326_isreg_precious(struct device *dev, unsigned int reg) |
| 208 | { |
| 209 | switch (reg) { |
| 210 | case ZPA2326_INT_SOURCE_REG: |
| 211 | case ZPA2326_PRESS_OUT_H_REG: |
| 212 | return true; |
| 213 | |
| 214 | default: |
| 215 | return false; |
| 216 | } |
| 217 | } |
| 218 | EXPORT_SYMBOL_GPL(zpa2326_isreg_precious); |
| 219 | |
| 220 | /** |
| 221 | * zpa2326_enable_device() - Enable device, i.e. get out of low power mode. |
| 222 | * @indio_dev: The IIO device associated with the hardware to enable. |
| 223 | * |
| 224 | * Required to access complete register space and to perform any sampling |
| 225 | * or control operations. |
| 226 | * |
| 227 | * Return: Zero when successful, a negative error code otherwise. |
| 228 | */ |
| 229 | static int zpa2326_enable_device(const struct iio_dev *indio_dev) |
| 230 | { |
| 231 | int err; |
| 232 | |
| 233 | err = regmap_write(((struct zpa2326_private *) |
| 234 | iio_priv(indio_dev))->regmap, |
| 235 | ZPA2326_CTRL_REG0_REG, ZPA2326_CTRL_REG0_ENABLE); |
| 236 | if (err) { |
| 237 | zpa2326_err(indio_dev, "failed to enable device (%d)", err); |
| 238 | return err; |
| 239 | } |
| 240 | |
| 241 | zpa2326_dbg(indio_dev, "enabled"); |
| 242 | |
| 243 | return 0; |
| 244 | } |
| 245 | |
| 246 | /** |
| 247 | * zpa2326_sleep() - Disable device, i.e. switch to low power mode. |
| 248 | * @indio_dev: The IIO device associated with the hardware to disable. |
| 249 | * |
| 250 | * Only %ZPA2326_DEVICE_ID_REG and %ZPA2326_CTRL_REG0_REG registers may be |
| 251 | * accessed once device is in the disabled state. |
| 252 | * |
| 253 | * Return: Zero when successful, a negative error code otherwise. |
| 254 | */ |
| 255 | static int zpa2326_sleep(const struct iio_dev *indio_dev) |
| 256 | { |
| 257 | int err; |
| 258 | |
| 259 | err = regmap_write(((struct zpa2326_private *) |
| 260 | iio_priv(indio_dev))->regmap, |
| 261 | ZPA2326_CTRL_REG0_REG, 0); |
| 262 | if (err) { |
| 263 | zpa2326_err(indio_dev, "failed to sleep (%d)", err); |
| 264 | return err; |
| 265 | } |
| 266 | |
| 267 | zpa2326_dbg(indio_dev, "sleeping"); |
| 268 | |
| 269 | return 0; |
| 270 | } |
| 271 | |
| 272 | /** |
| 273 | * zpa2326_reset_device() - Reset device to default hardware state. |
| 274 | * @indio_dev: The IIO device associated with the hardware to reset. |
| 275 | * |
| 276 | * Disable sampling and empty hardware FIFO. |
| 277 | * Device must be enabled before reset, i.e. not in low power mode. |
| 278 | * |
| 279 | * Return: Zero when successful, a negative error code otherwise. |
| 280 | */ |
| 281 | static int zpa2326_reset_device(const struct iio_dev *indio_dev) |
| 282 | { |
| 283 | int err; |
| 284 | |
| 285 | err = regmap_write(((struct zpa2326_private *) |
| 286 | iio_priv(indio_dev))->regmap, |
| 287 | ZPA2326_CTRL_REG2_REG, ZPA2326_CTRL_REG2_SWRESET); |
| 288 | if (err) { |
| 289 | zpa2326_err(indio_dev, "failed to reset device (%d)", err); |
| 290 | return err; |
| 291 | } |
| 292 | |
| 293 | usleep_range(ZPA2326_TPUP_USEC_MIN, ZPA2326_TPUP_USEC_MAX); |
| 294 | |
| 295 | zpa2326_dbg(indio_dev, "reset"); |
| 296 | |
| 297 | return 0; |
| 298 | } |
| 299 | |
| 300 | /** |
| 301 | * zpa2326_start_oneshot() - Start a single sampling cycle, i.e. in one shot |
| 302 | * mode. |
| 303 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 304 | * |
| 305 | * Device must have been previously enabled and configured for one shot mode. |
| 306 | * Device will be switched back to low power mode at end of cycle. |
| 307 | * |
| 308 | * Return: Zero when successful, a negative error code otherwise. |
| 309 | */ |
| 310 | static int zpa2326_start_oneshot(const struct iio_dev *indio_dev) |
| 311 | { |
| 312 | int err; |
| 313 | |
| 314 | err = regmap_write(((struct zpa2326_private *) |
| 315 | iio_priv(indio_dev))->regmap, |
| 316 | ZPA2326_CTRL_REG0_REG, |
| 317 | ZPA2326_CTRL_REG0_ENABLE | |
| 318 | ZPA2326_CTRL_REG0_ONE_SHOT); |
| 319 | if (err) { |
| 320 | zpa2326_err(indio_dev, "failed to start one shot cycle (%d)", |
| 321 | err); |
| 322 | return err; |
| 323 | } |
| 324 | |
| 325 | zpa2326_dbg(indio_dev, "one shot cycle started"); |
| 326 | |
| 327 | return 0; |
| 328 | } |
| 329 | |
| 330 | /** |
| 331 | * zpa2326_power_on() - Power on device to allow subsequent configuration. |
| 332 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 333 | * @private: Internal private state related to @indio_dev. |
| 334 | * |
| 335 | * Sampling will be disabled, preventing strange things from happening in our |
| 336 | * back. Hardware FIFO content will be cleared. |
| 337 | * When successful, device will be left in the enabled state to allow further |
| 338 | * configuration. |
| 339 | * |
| 340 | * Return: Zero when successful, a negative error code otherwise. |
| 341 | */ |
| 342 | static int zpa2326_power_on(const struct iio_dev *indio_dev, |
| 343 | const struct zpa2326_private *private) |
| 344 | { |
| 345 | int err; |
| 346 | |
| 347 | err = regulator_enable(private->vref); |
| 348 | if (err) |
| 349 | return err; |
| 350 | |
| 351 | err = regulator_enable(private->vdd); |
| 352 | if (err) |
| 353 | goto vref; |
| 354 | |
| 355 | zpa2326_dbg(indio_dev, "powered on"); |
| 356 | |
| 357 | err = zpa2326_enable_device(indio_dev); |
| 358 | if (err) |
| 359 | goto vdd; |
| 360 | |
| 361 | err = zpa2326_reset_device(indio_dev); |
| 362 | if (err) |
| 363 | goto sleep; |
| 364 | |
| 365 | return 0; |
| 366 | |
| 367 | sleep: |
| 368 | zpa2326_sleep(indio_dev); |
| 369 | vdd: |
| 370 | regulator_disable(private->vdd); |
| 371 | vref: |
| 372 | regulator_disable(private->vref); |
| 373 | |
| 374 | zpa2326_dbg(indio_dev, "powered off"); |
| 375 | |
| 376 | return err; |
| 377 | } |
| 378 | |
| 379 | /** |
| 380 | * zpa2326_power_off() - Power off device, i.e. disable attached power |
| 381 | * regulators. |
| 382 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 383 | * @private: Internal private state related to @indio_dev. |
| 384 | * |
| 385 | * Return: Zero when successful, a negative error code otherwise. |
| 386 | */ |
| 387 | static void zpa2326_power_off(const struct iio_dev *indio_dev, |
| 388 | const struct zpa2326_private *private) |
| 389 | { |
| 390 | regulator_disable(private->vdd); |
| 391 | regulator_disable(private->vref); |
| 392 | |
| 393 | zpa2326_dbg(indio_dev, "powered off"); |
| 394 | } |
| 395 | |
| 396 | /** |
| 397 | * zpa2326_config_oneshot() - Setup device for one shot / on demand mode. |
| 398 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 399 | * @irq: Optional interrupt line the hardware uses to notify new data |
| 400 | * samples are ready. Negative or zero values indicate no interrupts |
| 401 | * are available, meaning polling is required. |
| 402 | * |
| 403 | * Output Data Rate is configured for the highest possible rate so that |
| 404 | * conversion time and power consumption are reduced to a minimum. |
| 405 | * Note that hardware internal averaging machinery (not implemented in this |
| 406 | * driver) is not applicable in this mode. |
| 407 | * |
| 408 | * Device must have been previously enabled before calling |
| 409 | * zpa2326_config_oneshot(). |
| 410 | * |
| 411 | * Return: Zero when successful, a negative error code otherwise. |
| 412 | */ |
| 413 | static int zpa2326_config_oneshot(const struct iio_dev *indio_dev, |
| 414 | int irq) |
| 415 | { |
| 416 | struct regmap *regs = ((struct zpa2326_private *) |
| 417 | iio_priv(indio_dev))->regmap; |
| 418 | const struct zpa2326_frequency *freq = zpa2326_highest_frequency(); |
| 419 | int err; |
| 420 | |
| 421 | /* Setup highest available Output Data Rate for one shot mode. */ |
| 422 | err = regmap_write(regs, ZPA2326_CTRL_REG3_REG, freq->odr); |
| 423 | if (err) |
| 424 | return err; |
| 425 | |
| 426 | if (irq > 0) { |
| 427 | /* Request interrupt when new sample is available. */ |
| 428 | err = regmap_write(regs, ZPA2326_CTRL_REG1_REG, |
| 429 | (u8)~ZPA2326_CTRL_REG1_MASK_DATA_READY); |
| 430 | |
| 431 | if (err) { |
| 432 | dev_err(indio_dev->dev.parent, |
| 433 | "failed to setup one shot mode (%d)", err); |
| 434 | return err; |
| 435 | } |
| 436 | } |
| 437 | |
| 438 | zpa2326_dbg(indio_dev, "one shot mode setup @%dHz", freq->hz); |
| 439 | |
| 440 | return 0; |
| 441 | } |
| 442 | |
| 443 | /** |
| 444 | * zpa2326_clear_fifo() - Clear remaining entries in hardware FIFO. |
| 445 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 446 | * @min_count: Number of samples present within hardware FIFO. |
| 447 | * |
| 448 | * @min_count argument is a hint corresponding to the known minimum number of |
| 449 | * samples currently living in the FIFO. This allows to reduce the number of bus |
| 450 | * accesses by skipping status register read operation as long as we know for |
| 451 | * sure there are still entries left. |
| 452 | * |
| 453 | * Return: Zero when successful, a negative error code otherwise. |
| 454 | */ |
| 455 | static int zpa2326_clear_fifo(const struct iio_dev *indio_dev, |
| 456 | unsigned int min_count) |
| 457 | { |
| 458 | struct regmap *regs = ((struct zpa2326_private *) |
| 459 | iio_priv(indio_dev))->regmap; |
| 460 | int err; |
| 461 | unsigned int val; |
| 462 | |
| 463 | if (!min_count) { |
| 464 | /* |
| 465 | * No hint: read status register to determine whether FIFO is |
| 466 | * empty or not. |
| 467 | */ |
| 468 | err = regmap_read(regs, ZPA2326_STATUS_REG, &val); |
| 469 | |
| 470 | if (err < 0) |
| 471 | goto err; |
| 472 | |
| 473 | if (val & ZPA2326_STATUS_FIFO_E) |
| 474 | /* Fifo is empty: nothing to trash. */ |
| 475 | return 0; |
| 476 | } |
| 477 | |
| 478 | /* Clear FIFO. */ |
| 479 | do { |
| 480 | /* |
| 481 | * A single fetch from pressure MSB register is enough to pop |
| 482 | * values out of FIFO. |
| 483 | */ |
| 484 | err = regmap_read(regs, ZPA2326_PRESS_OUT_H_REG, &val); |
| 485 | if (err < 0) |
| 486 | goto err; |
| 487 | |
| 488 | if (min_count) { |
| 489 | /* |
| 490 | * We know for sure there are at least min_count entries |
| 491 | * left in FIFO. Skip status register read. |
| 492 | */ |
| 493 | min_count--; |
| 494 | continue; |
| 495 | } |
| 496 | |
| 497 | err = regmap_read(regs, ZPA2326_STATUS_REG, &val); |
| 498 | if (err < 0) |
| 499 | goto err; |
| 500 | |
| 501 | } while (!(val & ZPA2326_STATUS_FIFO_E)); |
| 502 | |
| 503 | zpa2326_dbg(indio_dev, "FIFO cleared"); |
| 504 | |
| 505 | return 0; |
| 506 | |
| 507 | err: |
| 508 | zpa2326_err(indio_dev, "failed to clear FIFO (%d)", err); |
| 509 | |
| 510 | return err; |
| 511 | } |
| 512 | |
| 513 | /** |
| 514 | * zpa2326_dequeue_pressure() - Retrieve the most recent pressure sample from |
| 515 | * hardware FIFO. |
| 516 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 517 | * @pressure: Sampled pressure output. |
| 518 | * |
| 519 | * Note that ZPA2326 hardware FIFO stores pressure samples only. |
| 520 | * |
| 521 | * Return: Zero when successful, a negative error code otherwise. |
| 522 | */ |
| 523 | static int zpa2326_dequeue_pressure(const struct iio_dev *indio_dev, |
| 524 | u32 *pressure) |
| 525 | { |
| 526 | struct regmap *regs = ((struct zpa2326_private *) |
| 527 | iio_priv(indio_dev))->regmap; |
| 528 | unsigned int val; |
| 529 | int err; |
| 530 | int cleared = -1; |
| 531 | |
| 532 | err = regmap_read(regs, ZPA2326_STATUS_REG, &val); |
| 533 | if (err < 0) |
| 534 | return err; |
| 535 | |
| 536 | *pressure = 0; |
| 537 | |
| 538 | if (val & ZPA2326_STATUS_P_OR) { |
| 539 | /* |
| 540 | * Fifo overrun : first sample dequeued from FIFO is the |
| 541 | * newest. |
| 542 | */ |
| 543 | zpa2326_warn(indio_dev, "FIFO overflow"); |
| 544 | |
| 545 | err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, pressure, |
| 546 | 3); |
| 547 | if (err) |
| 548 | return err; |
| 549 | |
| 550 | #define ZPA2326_FIFO_DEPTH (16U) |
| 551 | /* Hardware FIFO may hold no more than 16 pressure samples. */ |
| 552 | return zpa2326_clear_fifo(indio_dev, ZPA2326_FIFO_DEPTH - 1); |
| 553 | } |
| 554 | |
| 555 | /* |
| 556 | * Fifo has not overflown : retrieve newest sample. We need to pop |
| 557 | * values out until FIFO is empty : last fetched pressure is the newest. |
| 558 | * In nominal cases, we should find a single queued sample only. |
| 559 | */ |
| 560 | do { |
| 561 | err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, pressure, |
| 562 | 3); |
| 563 | if (err) |
| 564 | return err; |
| 565 | |
| 566 | err = regmap_read(regs, ZPA2326_STATUS_REG, &val); |
| 567 | if (err < 0) |
| 568 | return err; |
| 569 | |
| 570 | cleared++; |
| 571 | } while (!(val & ZPA2326_STATUS_FIFO_E)); |
| 572 | |
| 573 | if (cleared) |
| 574 | /* |
| 575 | * Samples were pushed by hardware during previous rounds but we |
| 576 | * didn't consume them fast enough: inform user. |
| 577 | */ |
| 578 | zpa2326_dbg(indio_dev, "cleared %d FIFO entries", cleared); |
| 579 | |
| 580 | return 0; |
| 581 | } |
| 582 | |
| 583 | /** |
| 584 | * zpa2326_fill_sample_buffer() - Enqueue new channel samples to IIO buffer. |
| 585 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 586 | * @private: Internal private state related to @indio_dev. |
| 587 | * |
| 588 | * Return: Zero when successful, a negative error code otherwise. |
| 589 | */ |
| 590 | static int zpa2326_fill_sample_buffer(struct iio_dev *indio_dev, |
| 591 | const struct zpa2326_private *private) |
| 592 | { |
| 593 | struct { |
| 594 | u32 pressure; |
| 595 | u16 temperature; |
| 596 | u64 timestamp; |
| 597 | } sample; |
| 598 | int err; |
| 599 | |
| 600 | if (test_bit(0, indio_dev->active_scan_mask)) { |
| 601 | /* Get current pressure from hardware FIFO. */ |
| 602 | err = zpa2326_dequeue_pressure(indio_dev, &sample.pressure); |
| 603 | if (err) { |
| 604 | zpa2326_warn(indio_dev, "failed to fetch pressure (%d)", |
| 605 | err); |
| 606 | return err; |
| 607 | } |
| 608 | } |
| 609 | |
| 610 | if (test_bit(1, indio_dev->active_scan_mask)) { |
| 611 | /* Get current temperature. */ |
| 612 | err = regmap_bulk_read(private->regmap, ZPA2326_TEMP_OUT_L_REG, |
| 613 | &sample.temperature, 2); |
| 614 | if (err) { |
| 615 | zpa2326_warn(indio_dev, |
| 616 | "failed to fetch temperature (%d)", err); |
| 617 | return err; |
| 618 | } |
| 619 | } |
| 620 | |
| 621 | /* |
| 622 | * Now push samples using timestamp stored either : |
| 623 | * - by hardware interrupt handler if interrupt is available: see |
| 624 | * zpa2326_handle_irq(), |
| 625 | * - or oneshot completion polling machinery : see |
| 626 | * zpa2326_trigger_handler(). |
| 627 | */ |
| 628 | zpa2326_dbg(indio_dev, "filling raw samples buffer"); |
| 629 | |
| 630 | iio_push_to_buffers_with_timestamp(indio_dev, &sample, |
| 631 | private->timestamp); |
| 632 | |
| 633 | return 0; |
| 634 | } |
| 635 | |
| 636 | #ifdef CONFIG_PM |
| 637 | static int zpa2326_runtime_suspend(struct device *parent) |
| 638 | { |
| 639 | const struct iio_dev *indio_dev = dev_get_drvdata(parent); |
| 640 | |
| 641 | if (pm_runtime_autosuspend_expiration(parent)) |
| 642 | /* Userspace changed autosuspend delay. */ |
| 643 | return -EAGAIN; |
| 644 | |
| 645 | zpa2326_power_off(indio_dev, iio_priv(indio_dev)); |
| 646 | |
| 647 | return 0; |
| 648 | } |
| 649 | |
| 650 | static int zpa2326_runtime_resume(struct device *parent) |
| 651 | { |
| 652 | const struct iio_dev *indio_dev = dev_get_drvdata(parent); |
| 653 | |
| 654 | return zpa2326_power_on(indio_dev, iio_priv(indio_dev)); |
| 655 | } |
| 656 | |
| 657 | const struct dev_pm_ops zpa2326_pm_ops = { |
| 658 | SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, |
| 659 | pm_runtime_force_resume) |
| 660 | SET_RUNTIME_PM_OPS(zpa2326_runtime_suspend, zpa2326_runtime_resume, |
| 661 | NULL) |
| 662 | }; |
| 663 | EXPORT_SYMBOL_GPL(zpa2326_pm_ops); |
| 664 | |
| 665 | /** |
| 666 | * zpa2326_resume() - Request the PM layer to power supply the device. |
| 667 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 668 | * |
| 669 | * Return: |
| 670 | * < 0 - a negative error code meaning failure ; |
| 671 | * 0 - success, device has just been powered up ; |
| 672 | * 1 - success, device was already powered. |
| 673 | */ |
| 674 | static int zpa2326_resume(const struct iio_dev *indio_dev) |
| 675 | { |
| 676 | int err; |
| 677 | |
| 678 | err = pm_runtime_get_sync(indio_dev->dev.parent); |
| 679 | if (err < 0) |
| 680 | return err; |
| 681 | |
| 682 | if (err > 0) { |
| 683 | /* |
| 684 | * Device was already power supplied: get it out of low power |
| 685 | * mode and inform caller. |
| 686 | */ |
| 687 | zpa2326_enable_device(indio_dev); |
| 688 | return 1; |
| 689 | } |
| 690 | |
| 691 | /* Inform caller device has just been brought back to life. */ |
| 692 | return 0; |
| 693 | } |
| 694 | |
| 695 | /** |
| 696 | * zpa2326_suspend() - Schedule a power down using autosuspend feature of PM |
| 697 | * layer. |
| 698 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 699 | * |
| 700 | * Device is switched to low power mode at first to save power even when |
| 701 | * attached regulator is a "dummy" one. |
| 702 | */ |
| 703 | static void zpa2326_suspend(struct iio_dev *indio_dev) |
| 704 | { |
| 705 | struct device *parent = indio_dev->dev.parent; |
| 706 | |
| 707 | zpa2326_sleep(indio_dev); |
| 708 | |
| 709 | pm_runtime_mark_last_busy(parent); |
| 710 | pm_runtime_put_autosuspend(parent); |
| 711 | } |
| 712 | |
| 713 | static void zpa2326_init_runtime(struct device *parent) |
| 714 | { |
| 715 | pm_runtime_get_noresume(parent); |
| 716 | pm_runtime_set_active(parent); |
| 717 | pm_runtime_enable(parent); |
| 718 | pm_runtime_set_autosuspend_delay(parent, 1000); |
| 719 | pm_runtime_use_autosuspend(parent); |
| 720 | pm_runtime_mark_last_busy(parent); |
| 721 | pm_runtime_put_autosuspend(parent); |
| 722 | } |
| 723 | |
| 724 | static void zpa2326_fini_runtime(struct device *parent) |
| 725 | { |
| 726 | pm_runtime_disable(parent); |
| 727 | pm_runtime_set_suspended(parent); |
| 728 | } |
| 729 | #else /* !CONFIG_PM */ |
| 730 | static int zpa2326_resume(const struct iio_dev *indio_dev) |
| 731 | { |
| 732 | zpa2326_enable_device(indio_dev); |
| 733 | |
| 734 | return 0; |
| 735 | } |
| 736 | |
| 737 | static void zpa2326_suspend(struct iio_dev *indio_dev) |
| 738 | { |
| 739 | zpa2326_sleep(indio_dev); |
| 740 | } |
| 741 | |
| 742 | #define zpa2326_init_runtime(_parent) |
| 743 | #define zpa2326_fini_runtime(_parent) |
| 744 | #endif /* !CONFIG_PM */ |
| 745 | |
| 746 | /** |
| 747 | * zpa2326_handle_irq() - Process hardware interrupts. |
| 748 | * @irq: Interrupt line the hardware uses to notify new data has arrived. |
| 749 | * @data: The IIO device associated with the sampling hardware. |
| 750 | * |
| 751 | * Timestamp buffered samples as soon as possible then schedule threaded bottom |
| 752 | * half. |
| 753 | * |
| 754 | * Return: Always successful. |
| 755 | */ |
| 756 | static irqreturn_t zpa2326_handle_irq(int irq, void *data) |
| 757 | { |
| 758 | struct iio_dev *indio_dev = (struct iio_dev *)data; |
| 759 | |
| 760 | if (iio_buffer_enabled(indio_dev)) { |
| 761 | /* Timestamping needed for buffered sampling only. */ |
| 762 | ((struct zpa2326_private *) |
| 763 | iio_priv(indio_dev))->timestamp = iio_get_time_ns(indio_dev); |
| 764 | } |
| 765 | |
| 766 | return IRQ_WAKE_THREAD; |
| 767 | } |
| 768 | |
| 769 | /** |
| 770 | * zpa2326_handle_threaded_irq() - Interrupt bottom-half handler. |
| 771 | * @irq: Interrupt line the hardware uses to notify new data has arrived. |
| 772 | * @data: The IIO device associated with the sampling hardware. |
| 773 | * |
| 774 | * Mainly ensures interrupt is caused by a real "new sample available" |
| 775 | * condition. This relies upon the ability to perform blocking / sleeping bus |
| 776 | * accesses to slave's registers. This is why zpa2326_handle_threaded_irq() is |
| 777 | * called from within a thread, i.e. not called from hard interrupt context. |
| 778 | * |
| 779 | * When device is using its own internal hardware trigger in continuous sampling |
| 780 | * mode, data are available into hardware FIFO once interrupt has occurred. All |
| 781 | * we have to do is to dispatch the trigger, which in turn will fetch data and |
| 782 | * fill IIO buffer. |
| 783 | * |
| 784 | * When not using its own internal hardware trigger, the device has been |
| 785 | * configured in one-shot mode either by an external trigger or the IIO read_raw |
| 786 | * hook. This means one of the latter is currently waiting for sampling |
| 787 | * completion, in which case we must simply wake it up. |
| 788 | * |
| 789 | * See zpa2326_trigger_handler(). |
| 790 | * |
| 791 | * Return: |
| 792 | * %IRQ_NONE - no consistent interrupt happened ; |
| 793 | * %IRQ_HANDLED - there was new samples available. |
| 794 | */ |
| 795 | static irqreturn_t zpa2326_handle_threaded_irq(int irq, void *data) |
| 796 | { |
| 797 | struct iio_dev *indio_dev = (struct iio_dev *)data; |
| 798 | struct zpa2326_private *priv = iio_priv(indio_dev); |
| 799 | unsigned int val; |
| 800 | bool cont; |
| 801 | irqreturn_t ret = IRQ_NONE; |
| 802 | |
| 803 | /* |
| 804 | * Are we using our own internal trigger in triggered buffer mode, i.e., |
| 805 | * currently working in continuous sampling mode ? |
| 806 | */ |
| 807 | cont = (iio_buffer_enabled(indio_dev) && |
| 808 | iio_trigger_using_own(indio_dev)); |
| 809 | |
| 810 | /* |
| 811 | * Device works according to a level interrupt scheme: reading interrupt |
| 812 | * status de-asserts interrupt line. |
| 813 | */ |
| 814 | priv->result = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val); |
| 815 | if (priv->result < 0) { |
| 816 | if (cont) |
| 817 | return IRQ_NONE; |
| 818 | |
| 819 | goto complete; |
| 820 | } |
| 821 | |
| 822 | /* Data ready is the only interrupt source we requested. */ |
| 823 | if (!(val & ZPA2326_INT_SOURCE_DATA_READY)) { |
| 824 | /* |
| 825 | * Interrupt happened but no new sample available: likely caused |
| 826 | * by spurious interrupts, in which case, returning IRQ_NONE |
| 827 | * allows to benefit from the generic spurious interrupts |
| 828 | * handling. |
| 829 | */ |
| 830 | zpa2326_warn(indio_dev, "unexpected interrupt status %02x", |
| 831 | val); |
| 832 | |
| 833 | if (cont) |
| 834 | return IRQ_NONE; |
| 835 | |
| 836 | priv->result = -ENODATA; |
| 837 | goto complete; |
| 838 | } |
| 839 | |
| 840 | /* New sample available: dispatch internal trigger consumers. */ |
| 841 | iio_trigger_poll_chained(priv->trigger); |
| 842 | |
| 843 | if (cont) |
| 844 | /* |
| 845 | * Internal hardware trigger has been scheduled above : it will |
| 846 | * fetch data on its own. |
| 847 | */ |
| 848 | return IRQ_HANDLED; |
| 849 | |
| 850 | ret = IRQ_HANDLED; |
| 851 | |
| 852 | complete: |
| 853 | /* |
| 854 | * Wake up direct or externaly triggered buffer mode waiters: see |
| 855 | * zpa2326_sample_oneshot() and zpa2326_trigger_handler(). |
| 856 | */ |
| 857 | complete(&priv->data_ready); |
| 858 | |
| 859 | return ret; |
| 860 | } |
| 861 | |
| 862 | /** |
| 863 | * zpa2326_wait_oneshot_completion() - Wait for oneshot data ready interrupt. |
| 864 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 865 | * @private: Internal private state related to @indio_dev. |
| 866 | * |
| 867 | * Return: Zero when successful, a negative error code otherwise. |
| 868 | */ |
| 869 | static int zpa2326_wait_oneshot_completion(const struct iio_dev *indio_dev, |
| 870 | struct zpa2326_private *private) |
| 871 | { |
Gregor Boirie | 03b262f | 2016-09-13 14:23:14 +0200 | [diff] [blame] | 872 | unsigned int val; |
Nicholas Mc Guire | c5eb48c | 2017-05-14 10:43:55 +0200 | [diff] [blame] | 873 | long timeout; |
Gregor Boirie | 03b262f | 2016-09-13 14:23:14 +0200 | [diff] [blame] | 874 | |
| 875 | zpa2326_dbg(indio_dev, "waiting for one shot completion interrupt"); |
| 876 | |
Nicholas Mc Guire | c5eb48c | 2017-05-14 10:43:55 +0200 | [diff] [blame] | 877 | timeout = wait_for_completion_interruptible_timeout( |
Gregor Boirie | 03b262f | 2016-09-13 14:23:14 +0200 | [diff] [blame] | 878 | &private->data_ready, ZPA2326_CONVERSION_JIFFIES); |
Nicholas Mc Guire | c5eb48c | 2017-05-14 10:43:55 +0200 | [diff] [blame] | 879 | if (timeout > 0) |
Gregor Boirie | 03b262f | 2016-09-13 14:23:14 +0200 | [diff] [blame] | 880 | /* |
| 881 | * Interrupt handler completed before timeout: return operation |
| 882 | * status. |
| 883 | */ |
| 884 | return private->result; |
| 885 | |
| 886 | /* Clear all interrupts just to be sure. */ |
| 887 | regmap_read(private->regmap, ZPA2326_INT_SOURCE_REG, &val); |
| 888 | |
Nicholas Mc Guire | c5eb48c | 2017-05-14 10:43:55 +0200 | [diff] [blame] | 889 | if (!timeout) { |
Gregor Boirie | 03b262f | 2016-09-13 14:23:14 +0200 | [diff] [blame] | 890 | /* Timed out. */ |
Nicholas Mc Guire | c5eb48c | 2017-05-14 10:43:55 +0200 | [diff] [blame] | 891 | zpa2326_warn(indio_dev, "no one shot interrupt occurred (%ld)", |
| 892 | timeout); |
Geert Uytterhoeven | 1680ca3 | 2017-07-05 10:14:59 +0200 | [diff] [blame] | 893 | return -ETIME; |
Nicholas Mc Guire | c5eb48c | 2017-05-14 10:43:55 +0200 | [diff] [blame] | 894 | } |
Gregor Boirie | 03b262f | 2016-09-13 14:23:14 +0200 | [diff] [blame] | 895 | |
Geert Uytterhoeven | 1680ca3 | 2017-07-05 10:14:59 +0200 | [diff] [blame] | 896 | zpa2326_warn(indio_dev, "wait for one shot interrupt cancelled"); |
| 897 | return -ERESTARTSYS; |
Gregor Boirie | 03b262f | 2016-09-13 14:23:14 +0200 | [diff] [blame] | 898 | } |
| 899 | |
| 900 | static int zpa2326_init_managed_irq(struct device *parent, |
| 901 | struct iio_dev *indio_dev, |
| 902 | struct zpa2326_private *private, |
| 903 | int irq) |
| 904 | { |
| 905 | int err; |
| 906 | |
| 907 | private->irq = irq; |
| 908 | |
| 909 | if (irq <= 0) { |
| 910 | /* |
| 911 | * Platform declared no interrupt line: device will be polled |
| 912 | * for data availability. |
| 913 | */ |
| 914 | dev_info(parent, "no interrupt found, running in polling mode"); |
| 915 | return 0; |
| 916 | } |
| 917 | |
| 918 | init_completion(&private->data_ready); |
| 919 | |
| 920 | /* Request handler to be scheduled into threaded interrupt context. */ |
| 921 | err = devm_request_threaded_irq(parent, irq, zpa2326_handle_irq, |
| 922 | zpa2326_handle_threaded_irq, |
| 923 | IRQF_TRIGGER_RISING | IRQF_ONESHOT, |
| 924 | dev_name(parent), indio_dev); |
| 925 | if (err) { |
| 926 | dev_err(parent, "failed to request interrupt %d (%d)", irq, |
| 927 | err); |
| 928 | return err; |
| 929 | } |
| 930 | |
| 931 | dev_info(parent, "using interrupt %d", irq); |
| 932 | |
| 933 | return 0; |
| 934 | } |
| 935 | |
| 936 | /** |
| 937 | * zpa2326_poll_oneshot_completion() - Actively poll for one shot data ready. |
| 938 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 939 | * |
| 940 | * Loop over registers content to detect end of sampling cycle. Used when DT |
| 941 | * declared no valid interrupt lines. |
| 942 | * |
| 943 | * Return: Zero when successful, a negative error code otherwise. |
| 944 | */ |
| 945 | static int zpa2326_poll_oneshot_completion(const struct iio_dev *indio_dev) |
| 946 | { |
| 947 | unsigned long tmout = jiffies + ZPA2326_CONVERSION_JIFFIES; |
| 948 | struct regmap *regs = ((struct zpa2326_private *) |
| 949 | iio_priv(indio_dev))->regmap; |
| 950 | unsigned int val; |
| 951 | int err; |
| 952 | |
| 953 | zpa2326_dbg(indio_dev, "polling for one shot completion"); |
| 954 | |
| 955 | /* |
| 956 | * At least, 100 ms is needed for the device to complete its one-shot |
| 957 | * cycle. |
| 958 | */ |
| 959 | if (msleep_interruptible(100)) |
| 960 | return -ERESTARTSYS; |
| 961 | |
| 962 | /* Poll for conversion completion in hardware. */ |
| 963 | while (true) { |
| 964 | err = regmap_read(regs, ZPA2326_CTRL_REG0_REG, &val); |
| 965 | if (err < 0) |
| 966 | goto err; |
| 967 | |
| 968 | if (!(val & ZPA2326_CTRL_REG0_ONE_SHOT)) |
| 969 | /* One-shot bit self clears at conversion end. */ |
| 970 | break; |
| 971 | |
| 972 | if (time_after(jiffies, tmout)) { |
| 973 | /* Prevent from waiting forever : let's time out. */ |
| 974 | err = -ETIME; |
| 975 | goto err; |
| 976 | } |
| 977 | |
| 978 | usleep_range(10000, 20000); |
| 979 | } |
| 980 | |
| 981 | /* |
| 982 | * In oneshot mode, pressure sample availability guarantees that |
| 983 | * temperature conversion has also completed : just check pressure |
| 984 | * status bit to keep things simple. |
| 985 | */ |
| 986 | err = regmap_read(regs, ZPA2326_STATUS_REG, &val); |
| 987 | if (err < 0) |
| 988 | goto err; |
| 989 | |
| 990 | if (!(val & ZPA2326_STATUS_P_DA)) { |
| 991 | /* No sample available. */ |
| 992 | err = -ENODATA; |
| 993 | goto err; |
| 994 | } |
| 995 | |
| 996 | return 0; |
| 997 | |
| 998 | err: |
| 999 | zpa2326_warn(indio_dev, "failed to poll one shot completion (%d)", err); |
| 1000 | |
| 1001 | return err; |
| 1002 | } |
| 1003 | |
| 1004 | /** |
| 1005 | * zpa2326_fetch_raw_sample() - Retrieve a raw sample and convert it to CPU |
| 1006 | * endianness. |
| 1007 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 1008 | * @type: Type of measurement / channel to fetch from. |
| 1009 | * @value: Sample output. |
| 1010 | * |
| 1011 | * Return: Zero when successful, a negative error code otherwise. |
| 1012 | */ |
| 1013 | static int zpa2326_fetch_raw_sample(const struct iio_dev *indio_dev, |
| 1014 | enum iio_chan_type type, |
| 1015 | int *value) |
| 1016 | { |
| 1017 | struct regmap *regs = ((struct zpa2326_private *) |
| 1018 | iio_priv(indio_dev))->regmap; |
| 1019 | int err; |
| 1020 | |
| 1021 | switch (type) { |
| 1022 | case IIO_PRESSURE: |
| 1023 | zpa2326_dbg(indio_dev, "fetching raw pressure sample"); |
| 1024 | |
| 1025 | err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, value, |
| 1026 | 3); |
| 1027 | if (err) { |
| 1028 | zpa2326_warn(indio_dev, "failed to fetch pressure (%d)", |
| 1029 | err); |
| 1030 | return err; |
| 1031 | } |
| 1032 | |
| 1033 | /* Pressure is a 24 bits wide little-endian unsigned int. */ |
| 1034 | *value = (((u8 *)value)[2] << 16) | (((u8 *)value)[1] << 8) | |
| 1035 | ((u8 *)value)[0]; |
| 1036 | |
| 1037 | return IIO_VAL_INT; |
| 1038 | |
| 1039 | case IIO_TEMP: |
| 1040 | zpa2326_dbg(indio_dev, "fetching raw temperature sample"); |
| 1041 | |
| 1042 | err = regmap_bulk_read(regs, ZPA2326_TEMP_OUT_L_REG, value, 2); |
| 1043 | if (err) { |
| 1044 | zpa2326_warn(indio_dev, |
| 1045 | "failed to fetch temperature (%d)", err); |
| 1046 | return err; |
| 1047 | } |
| 1048 | |
| 1049 | /* Temperature is a 16 bits wide little-endian signed int. */ |
| 1050 | *value = (int)le16_to_cpup((__le16 *)value); |
| 1051 | |
| 1052 | return IIO_VAL_INT; |
| 1053 | |
| 1054 | default: |
| 1055 | return -EINVAL; |
| 1056 | } |
| 1057 | } |
| 1058 | |
| 1059 | /** |
| 1060 | * zpa2326_sample_oneshot() - Perform a complete one shot sampling cycle. |
| 1061 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 1062 | * @type: Type of measurement / channel to fetch from. |
| 1063 | * @value: Sample output. |
| 1064 | * |
| 1065 | * Return: Zero when successful, a negative error code otherwise. |
| 1066 | */ |
| 1067 | static int zpa2326_sample_oneshot(struct iio_dev *indio_dev, |
| 1068 | enum iio_chan_type type, |
| 1069 | int *value) |
| 1070 | { |
| 1071 | int ret; |
| 1072 | struct zpa2326_private *priv; |
| 1073 | |
| 1074 | ret = iio_device_claim_direct_mode(indio_dev); |
| 1075 | if (ret) |
| 1076 | return ret; |
| 1077 | |
| 1078 | ret = zpa2326_resume(indio_dev); |
| 1079 | if (ret < 0) |
| 1080 | goto release; |
| 1081 | |
| 1082 | priv = iio_priv(indio_dev); |
| 1083 | |
| 1084 | if (ret > 0) { |
| 1085 | /* |
| 1086 | * We were already power supplied. Just clear hardware FIFO to |
| 1087 | * get rid of samples acquired during previous rounds (if any). |
| 1088 | * Sampling operation always generates both temperature and |
| 1089 | * pressure samples. The latter are always enqueued into |
| 1090 | * hardware FIFO. This may lead to situations were pressure |
| 1091 | * samples still sit into FIFO when previous cycle(s) fetched |
| 1092 | * temperature data only. |
| 1093 | * Hence, we need to clear hardware FIFO content to prevent from |
| 1094 | * getting outdated values at the end of current cycle. |
| 1095 | */ |
| 1096 | if (type == IIO_PRESSURE) { |
| 1097 | ret = zpa2326_clear_fifo(indio_dev, 0); |
| 1098 | if (ret) |
| 1099 | goto suspend; |
| 1100 | } |
| 1101 | } else { |
| 1102 | /* |
| 1103 | * We have just been power supplied, i.e. device is in default |
| 1104 | * "out of reset" state, meaning we need to reconfigure it |
| 1105 | * entirely. |
| 1106 | */ |
| 1107 | ret = zpa2326_config_oneshot(indio_dev, priv->irq); |
| 1108 | if (ret) |
| 1109 | goto suspend; |
| 1110 | } |
| 1111 | |
| 1112 | /* Start a sampling cycle in oneshot mode. */ |
| 1113 | ret = zpa2326_start_oneshot(indio_dev); |
| 1114 | if (ret) |
| 1115 | goto suspend; |
| 1116 | |
| 1117 | /* Wait for sampling cycle to complete. */ |
| 1118 | if (priv->irq > 0) |
| 1119 | ret = zpa2326_wait_oneshot_completion(indio_dev, priv); |
| 1120 | else |
| 1121 | ret = zpa2326_poll_oneshot_completion(indio_dev); |
| 1122 | |
| 1123 | if (ret) |
| 1124 | goto suspend; |
| 1125 | |
| 1126 | /* Retrieve raw sample value and convert it to CPU endianness. */ |
| 1127 | ret = zpa2326_fetch_raw_sample(indio_dev, type, value); |
| 1128 | |
| 1129 | suspend: |
| 1130 | zpa2326_suspend(indio_dev); |
| 1131 | release: |
| 1132 | iio_device_release_direct_mode(indio_dev); |
| 1133 | |
| 1134 | return ret; |
| 1135 | } |
| 1136 | |
| 1137 | /** |
| 1138 | * zpa2326_trigger_handler() - Perform an IIO buffered sampling round in one |
| 1139 | * shot mode. |
| 1140 | * @irq: The software interrupt assigned to @data |
| 1141 | * @data: The IIO poll function dispatched by external trigger our device is |
| 1142 | * attached to. |
| 1143 | * |
| 1144 | * Bottom-half handler called by the IIO trigger to which our device is |
| 1145 | * currently attached. Allows us to synchronize this device buffered sampling |
| 1146 | * either with external events (such as timer expiration, external device sample |
| 1147 | * ready, etc...) or with its own interrupt (internal hardware trigger). |
| 1148 | * |
| 1149 | * When using an external trigger, basically run the same sequence of operations |
| 1150 | * as for zpa2326_sample_oneshot() with the following hereafter. Hardware FIFO |
| 1151 | * is not cleared since already done at buffering enable time and samples |
| 1152 | * dequeueing always retrieves the most recent value. |
| 1153 | * |
| 1154 | * Otherwise, when internal hardware trigger has dispatched us, just fetch data |
| 1155 | * from hardware FIFO. |
| 1156 | * |
| 1157 | * Fetched data will pushed unprocessed to IIO buffer since samples conversion |
| 1158 | * is delegated to userspace in buffered mode (endianness, etc...). |
| 1159 | * |
| 1160 | * Return: |
| 1161 | * %IRQ_NONE - no consistent interrupt happened ; |
| 1162 | * %IRQ_HANDLED - there was new samples available. |
| 1163 | */ |
| 1164 | static irqreturn_t zpa2326_trigger_handler(int irq, void *data) |
| 1165 | { |
| 1166 | struct iio_dev *indio_dev = ((struct iio_poll_func *) |
| 1167 | data)->indio_dev; |
| 1168 | struct zpa2326_private *priv = iio_priv(indio_dev); |
| 1169 | bool cont; |
| 1170 | |
| 1171 | /* |
| 1172 | * We have been dispatched, meaning we are in triggered buffer mode. |
| 1173 | * Using our own internal trigger implies we are currently in continuous |
| 1174 | * hardware sampling mode. |
| 1175 | */ |
| 1176 | cont = iio_trigger_using_own(indio_dev); |
| 1177 | |
| 1178 | if (!cont) { |
| 1179 | /* On demand sampling : start a one shot cycle. */ |
| 1180 | if (zpa2326_start_oneshot(indio_dev)) |
| 1181 | goto out; |
| 1182 | |
| 1183 | /* Wait for sampling cycle to complete. */ |
| 1184 | if (priv->irq <= 0) { |
| 1185 | /* No interrupt available: poll for completion. */ |
| 1186 | if (zpa2326_poll_oneshot_completion(indio_dev)) |
| 1187 | goto out; |
| 1188 | |
| 1189 | /* Only timestamp sample once it is ready. */ |
| 1190 | priv->timestamp = iio_get_time_ns(indio_dev); |
| 1191 | } else { |
| 1192 | /* Interrupt handlers will timestamp for us. */ |
| 1193 | if (zpa2326_wait_oneshot_completion(indio_dev, priv)) |
| 1194 | goto out; |
| 1195 | } |
| 1196 | } |
| 1197 | |
| 1198 | /* Enqueue to IIO buffer / userspace. */ |
| 1199 | zpa2326_fill_sample_buffer(indio_dev, priv); |
| 1200 | |
| 1201 | out: |
| 1202 | if (!cont) |
| 1203 | /* Don't switch to low power if sampling continuously. */ |
| 1204 | zpa2326_sleep(indio_dev); |
| 1205 | |
| 1206 | /* Inform attached trigger we are done. */ |
| 1207 | iio_trigger_notify_done(indio_dev->trig); |
| 1208 | |
| 1209 | return IRQ_HANDLED; |
| 1210 | } |
| 1211 | |
| 1212 | /** |
| 1213 | * zpa2326_preenable_buffer() - Prepare device for configuring triggered |
| 1214 | * sampling |
| 1215 | * modes. |
| 1216 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 1217 | * |
| 1218 | * Basically power up device. |
| 1219 | * Called with IIO device's lock held. |
| 1220 | * |
| 1221 | * Return: Zero when successful, a negative error code otherwise. |
| 1222 | */ |
| 1223 | static int zpa2326_preenable_buffer(struct iio_dev *indio_dev) |
| 1224 | { |
| 1225 | int ret = zpa2326_resume(indio_dev); |
| 1226 | |
| 1227 | if (ret < 0) |
| 1228 | return ret; |
| 1229 | |
| 1230 | /* Tell zpa2326_postenable_buffer() if we have just been powered on. */ |
| 1231 | ((struct zpa2326_private *) |
| 1232 | iio_priv(indio_dev))->waken = iio_priv(indio_dev); |
| 1233 | |
| 1234 | return 0; |
| 1235 | } |
| 1236 | |
| 1237 | /** |
| 1238 | * zpa2326_postenable_buffer() - Configure device for triggered sampling. |
| 1239 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 1240 | * |
| 1241 | * Basically setup one-shot mode if plugging external trigger. |
| 1242 | * Otherwise, let internal trigger configure continuous sampling : |
| 1243 | * see zpa2326_set_trigger_state(). |
| 1244 | * |
| 1245 | * If an error is returned, IIO layer will call our postdisable hook for us, |
| 1246 | * i.e. no need to explicitly power device off here. |
| 1247 | * Called with IIO device's lock held. |
| 1248 | * |
| 1249 | * Called with IIO device's lock held. |
| 1250 | * |
| 1251 | * Return: Zero when successful, a negative error code otherwise. |
| 1252 | */ |
| 1253 | static int zpa2326_postenable_buffer(struct iio_dev *indio_dev) |
| 1254 | { |
| 1255 | const struct zpa2326_private *priv = iio_priv(indio_dev); |
| 1256 | int err; |
| 1257 | |
| 1258 | if (!priv->waken) { |
| 1259 | /* |
| 1260 | * We were already power supplied. Just clear hardware FIFO to |
| 1261 | * get rid of samples acquired during previous rounds (if any). |
| 1262 | */ |
| 1263 | err = zpa2326_clear_fifo(indio_dev, 0); |
| 1264 | if (err) |
| 1265 | goto err; |
| 1266 | } |
| 1267 | |
| 1268 | if (!iio_trigger_using_own(indio_dev) && priv->waken) { |
| 1269 | /* |
| 1270 | * We are using an external trigger and we have just been |
| 1271 | * powered up: reconfigure one-shot mode. |
| 1272 | */ |
| 1273 | err = zpa2326_config_oneshot(indio_dev, priv->irq); |
| 1274 | if (err) |
| 1275 | goto err; |
| 1276 | } |
| 1277 | |
| 1278 | /* Plug our own trigger event handler. */ |
| 1279 | err = iio_triggered_buffer_postenable(indio_dev); |
| 1280 | if (err) |
| 1281 | goto err; |
| 1282 | |
| 1283 | return 0; |
| 1284 | |
| 1285 | err: |
| 1286 | zpa2326_err(indio_dev, "failed to enable buffering (%d)", err); |
| 1287 | |
| 1288 | return err; |
| 1289 | } |
| 1290 | |
| 1291 | static int zpa2326_postdisable_buffer(struct iio_dev *indio_dev) |
| 1292 | { |
| 1293 | zpa2326_suspend(indio_dev); |
| 1294 | |
| 1295 | return 0; |
| 1296 | } |
| 1297 | |
| 1298 | static const struct iio_buffer_setup_ops zpa2326_buffer_setup_ops = { |
| 1299 | .preenable = zpa2326_preenable_buffer, |
| 1300 | .postenable = zpa2326_postenable_buffer, |
| 1301 | .predisable = iio_triggered_buffer_predisable, |
| 1302 | .postdisable = zpa2326_postdisable_buffer |
| 1303 | }; |
| 1304 | |
| 1305 | /** |
| 1306 | * zpa2326_set_trigger_state() - Start / stop continuous sampling. |
| 1307 | * @trig: The trigger being attached to IIO device associated with the sampling |
| 1308 | * hardware. |
| 1309 | * @state: Tell whether to start (true) or stop (false) |
| 1310 | * |
| 1311 | * Basically enable / disable hardware continuous sampling mode. |
| 1312 | * |
| 1313 | * Called with IIO device's lock held at postenable() or predisable() time. |
| 1314 | * |
| 1315 | * Return: Zero when successful, a negative error code otherwise. |
| 1316 | */ |
| 1317 | static int zpa2326_set_trigger_state(struct iio_trigger *trig, bool state) |
| 1318 | { |
| 1319 | const struct iio_dev *indio_dev = dev_get_drvdata( |
| 1320 | trig->dev.parent); |
| 1321 | const struct zpa2326_private *priv = iio_priv(indio_dev); |
| 1322 | int err; |
| 1323 | |
| 1324 | if (!state) { |
| 1325 | /* |
| 1326 | * Switch trigger off : in case of failure, interrupt is left |
| 1327 | * disabled in order to prevent handler from accessing released |
| 1328 | * resources. |
| 1329 | */ |
| 1330 | unsigned int val; |
| 1331 | |
| 1332 | /* |
| 1333 | * As device is working in continuous mode, handlers may be |
| 1334 | * accessing resources we are currently freeing... |
| 1335 | * Prevent this by disabling interrupt handlers and ensure |
| 1336 | * the device will generate no more interrupts unless explicitly |
| 1337 | * required to, i.e. by restoring back to default one shot mode. |
| 1338 | */ |
| 1339 | disable_irq(priv->irq); |
| 1340 | |
| 1341 | /* |
| 1342 | * Disable continuous sampling mode to restore settings for |
| 1343 | * one shot / direct sampling operations. |
| 1344 | */ |
| 1345 | err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG, |
| 1346 | zpa2326_highest_frequency()->odr); |
| 1347 | if (err) |
| 1348 | return err; |
| 1349 | |
| 1350 | /* |
| 1351 | * Now that device won't generate interrupts on its own, |
| 1352 | * acknowledge any currently active interrupts (may happen on |
| 1353 | * rare occasions while stopping continuous mode). |
| 1354 | */ |
| 1355 | err = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val); |
| 1356 | if (err < 0) |
| 1357 | return err; |
| 1358 | |
| 1359 | /* |
| 1360 | * Re-enable interrupts only if we can guarantee the device will |
| 1361 | * generate no more interrupts to prevent handlers from |
| 1362 | * accessing released resources. |
| 1363 | */ |
| 1364 | enable_irq(priv->irq); |
| 1365 | |
| 1366 | zpa2326_dbg(indio_dev, "continuous mode stopped"); |
| 1367 | } else { |
| 1368 | /* |
| 1369 | * Switch trigger on : start continuous sampling at required |
| 1370 | * frequency. |
| 1371 | */ |
| 1372 | |
| 1373 | if (priv->waken) { |
| 1374 | /* Enable interrupt if getting out of reset. */ |
| 1375 | err = regmap_write(priv->regmap, ZPA2326_CTRL_REG1_REG, |
| 1376 | (u8) |
| 1377 | ~ZPA2326_CTRL_REG1_MASK_DATA_READY); |
| 1378 | if (err) |
| 1379 | return err; |
| 1380 | } |
| 1381 | |
| 1382 | /* Enable continuous sampling at specified frequency. */ |
| 1383 | err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG, |
| 1384 | ZPA2326_CTRL_REG3_ENABLE_MEAS | |
| 1385 | priv->frequency->odr); |
| 1386 | if (err) |
| 1387 | return err; |
| 1388 | |
| 1389 | zpa2326_dbg(indio_dev, "continuous mode setup @%dHz", |
| 1390 | priv->frequency->hz); |
| 1391 | } |
| 1392 | |
| 1393 | return 0; |
| 1394 | } |
| 1395 | |
| 1396 | static const struct iio_trigger_ops zpa2326_trigger_ops = { |
| 1397 | .owner = THIS_MODULE, |
| 1398 | .set_trigger_state = zpa2326_set_trigger_state, |
| 1399 | }; |
| 1400 | |
| 1401 | /** |
| 1402 | * zpa2326_init_trigger() - Create an interrupt driven / hardware trigger |
| 1403 | * allowing to notify external devices a new sample is |
| 1404 | * ready. |
| 1405 | * @parent: Hardware sampling device @indio_dev is a child of. |
| 1406 | * @indio_dev: The IIO device associated with the sampling hardware. |
| 1407 | * @private: Internal private state related to @indio_dev. |
| 1408 | * @irq: Optional interrupt line the hardware uses to notify new data |
| 1409 | * samples are ready. Negative or zero values indicate no interrupts |
| 1410 | * are available, meaning polling is required. |
| 1411 | * |
| 1412 | * Only relevant when DT declares a valid interrupt line. |
| 1413 | * |
| 1414 | * Return: Zero when successful, a negative error code otherwise. |
| 1415 | */ |
| 1416 | static int zpa2326_init_managed_trigger(struct device *parent, |
| 1417 | struct iio_dev *indio_dev, |
| 1418 | struct zpa2326_private *private, |
| 1419 | int irq) |
| 1420 | { |
| 1421 | struct iio_trigger *trigger; |
| 1422 | int ret; |
| 1423 | |
| 1424 | if (irq <= 0) |
| 1425 | return 0; |
| 1426 | |
| 1427 | trigger = devm_iio_trigger_alloc(parent, "%s-dev%d", |
| 1428 | indio_dev->name, indio_dev->id); |
| 1429 | if (!trigger) |
| 1430 | return -ENOMEM; |
| 1431 | |
| 1432 | /* Basic setup. */ |
| 1433 | trigger->dev.parent = parent; |
| 1434 | trigger->ops = &zpa2326_trigger_ops; |
| 1435 | |
| 1436 | private->trigger = trigger; |
| 1437 | |
| 1438 | /* Register to triggers space. */ |
| 1439 | ret = devm_iio_trigger_register(parent, trigger); |
| 1440 | if (ret) |
| 1441 | dev_err(parent, "failed to register hardware trigger (%d)", |
| 1442 | ret); |
| 1443 | |
| 1444 | return ret; |
| 1445 | } |
| 1446 | |
| 1447 | static int zpa2326_get_frequency(const struct iio_dev *indio_dev) |
| 1448 | { |
| 1449 | return ((struct zpa2326_private *)iio_priv(indio_dev))->frequency->hz; |
| 1450 | } |
| 1451 | |
| 1452 | static int zpa2326_set_frequency(struct iio_dev *indio_dev, int hz) |
| 1453 | { |
| 1454 | struct zpa2326_private *priv = iio_priv(indio_dev); |
| 1455 | int freq; |
| 1456 | int err; |
| 1457 | |
| 1458 | /* Check if requested frequency is supported. */ |
| 1459 | for (freq = 0; freq < ARRAY_SIZE(zpa2326_sampling_frequencies); freq++) |
| 1460 | if (zpa2326_sampling_frequencies[freq].hz == hz) |
| 1461 | break; |
| 1462 | if (freq == ARRAY_SIZE(zpa2326_sampling_frequencies)) |
| 1463 | return -EINVAL; |
| 1464 | |
| 1465 | /* Don't allow changing frequency if buffered sampling is ongoing. */ |
| 1466 | err = iio_device_claim_direct_mode(indio_dev); |
| 1467 | if (err) |
| 1468 | return err; |
| 1469 | |
| 1470 | priv->frequency = &zpa2326_sampling_frequencies[freq]; |
| 1471 | |
| 1472 | iio_device_release_direct_mode(indio_dev); |
| 1473 | |
| 1474 | return 0; |
| 1475 | } |
| 1476 | |
| 1477 | /* Expose supported hardware sampling frequencies (Hz) through sysfs. */ |
| 1478 | static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1 5 11 23"); |
| 1479 | |
| 1480 | static struct attribute *zpa2326_attributes[] = { |
| 1481 | &iio_const_attr_sampling_frequency_available.dev_attr.attr, |
| 1482 | NULL |
| 1483 | }; |
| 1484 | |
| 1485 | static const struct attribute_group zpa2326_attribute_group = { |
| 1486 | .attrs = zpa2326_attributes, |
| 1487 | }; |
| 1488 | |
| 1489 | static int zpa2326_read_raw(struct iio_dev *indio_dev, |
| 1490 | struct iio_chan_spec const *chan, |
| 1491 | int *val, |
| 1492 | int *val2, |
| 1493 | long mask) |
| 1494 | { |
| 1495 | switch (mask) { |
| 1496 | case IIO_CHAN_INFO_RAW: |
| 1497 | return zpa2326_sample_oneshot(indio_dev, chan->type, val); |
| 1498 | |
| 1499 | case IIO_CHAN_INFO_SCALE: |
| 1500 | switch (chan->type) { |
| 1501 | case IIO_PRESSURE: |
| 1502 | /* |
| 1503 | * Pressure resolution is 1/64 Pascal. Scale to kPascal |
| 1504 | * as required by IIO ABI. |
| 1505 | */ |
| 1506 | *val = 1; |
| 1507 | *val2 = 64000; |
| 1508 | return IIO_VAL_FRACTIONAL; |
| 1509 | |
| 1510 | case IIO_TEMP: |
| 1511 | /* |
| 1512 | * Temperature follows the equation: |
| 1513 | * Temp[degC] = Tempcode * 0.00649 - 176.83 |
| 1514 | * where: |
| 1515 | * Tempcode is composed the raw sampled 16 bits. |
| 1516 | * |
| 1517 | * Hence, to produce a temperature in milli-degrees |
| 1518 | * Celsius according to IIO ABI, we need to apply the |
| 1519 | * following equation to raw samples: |
| 1520 | * Temp[milli degC] = (Tempcode + Offset) * Scale |
| 1521 | * where: |
| 1522 | * Offset = -176.83 / 0.00649 |
| 1523 | * Scale = 0.00649 * 1000 |
| 1524 | */ |
| 1525 | *val = 6; |
| 1526 | *val2 = 490000; |
| 1527 | return IIO_VAL_INT_PLUS_MICRO; |
| 1528 | |
| 1529 | default: |
| 1530 | return -EINVAL; |
| 1531 | } |
| 1532 | |
| 1533 | case IIO_CHAN_INFO_OFFSET: |
| 1534 | switch (chan->type) { |
| 1535 | case IIO_TEMP: |
| 1536 | *val = -17683000; |
| 1537 | *val2 = 649; |
| 1538 | return IIO_VAL_FRACTIONAL; |
| 1539 | |
| 1540 | default: |
| 1541 | return -EINVAL; |
| 1542 | } |
| 1543 | |
| 1544 | case IIO_CHAN_INFO_SAMP_FREQ: |
| 1545 | *val = zpa2326_get_frequency(indio_dev); |
| 1546 | return IIO_VAL_INT; |
| 1547 | |
| 1548 | default: |
| 1549 | return -EINVAL; |
| 1550 | } |
| 1551 | } |
| 1552 | |
| 1553 | static int zpa2326_write_raw(struct iio_dev *indio_dev, |
| 1554 | const struct iio_chan_spec *chan, |
| 1555 | int val, |
| 1556 | int val2, |
| 1557 | long mask) |
| 1558 | { |
| 1559 | if ((mask != IIO_CHAN_INFO_SAMP_FREQ) || val2) |
| 1560 | return -EINVAL; |
| 1561 | |
| 1562 | return zpa2326_set_frequency(indio_dev, val); |
| 1563 | } |
| 1564 | |
| 1565 | static const struct iio_chan_spec zpa2326_channels[] = { |
| 1566 | [0] = { |
| 1567 | .type = IIO_PRESSURE, |
| 1568 | .scan_index = 0, |
| 1569 | .scan_type = { |
| 1570 | .sign = 'u', |
| 1571 | .realbits = 24, |
| 1572 | .storagebits = 32, |
| 1573 | .endianness = IIO_LE, |
| 1574 | }, |
| 1575 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
| 1576 | BIT(IIO_CHAN_INFO_SCALE), |
| 1577 | .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), |
| 1578 | }, |
| 1579 | [1] = { |
| 1580 | .type = IIO_TEMP, |
| 1581 | .scan_index = 1, |
| 1582 | .scan_type = { |
| 1583 | .sign = 's', |
| 1584 | .realbits = 16, |
| 1585 | .storagebits = 16, |
| 1586 | .endianness = IIO_LE, |
| 1587 | }, |
| 1588 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
| 1589 | BIT(IIO_CHAN_INFO_SCALE) | |
| 1590 | BIT(IIO_CHAN_INFO_OFFSET), |
| 1591 | .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), |
| 1592 | }, |
| 1593 | [2] = IIO_CHAN_SOFT_TIMESTAMP(2), |
| 1594 | }; |
| 1595 | |
| 1596 | static const struct iio_info zpa2326_info = { |
| 1597 | .driver_module = THIS_MODULE, |
| 1598 | .attrs = &zpa2326_attribute_group, |
| 1599 | .read_raw = zpa2326_read_raw, |
| 1600 | .write_raw = zpa2326_write_raw, |
| 1601 | }; |
| 1602 | |
| 1603 | static struct iio_dev *zpa2326_create_managed_iiodev(struct device *device, |
| 1604 | const char *name, |
| 1605 | struct regmap *regmap) |
| 1606 | { |
| 1607 | struct iio_dev *indio_dev; |
| 1608 | |
| 1609 | /* Allocate space to hold IIO device internal state. */ |
| 1610 | indio_dev = devm_iio_device_alloc(device, |
| 1611 | sizeof(struct zpa2326_private)); |
| 1612 | if (!indio_dev) |
| 1613 | return NULL; |
| 1614 | |
| 1615 | /* Setup for userspace synchronous on demand sampling. */ |
| 1616 | indio_dev->modes = INDIO_DIRECT_MODE; |
| 1617 | indio_dev->dev.parent = device; |
| 1618 | indio_dev->channels = zpa2326_channels; |
| 1619 | indio_dev->num_channels = ARRAY_SIZE(zpa2326_channels); |
| 1620 | indio_dev->name = name; |
| 1621 | indio_dev->info = &zpa2326_info; |
| 1622 | |
| 1623 | return indio_dev; |
| 1624 | } |
| 1625 | |
| 1626 | int zpa2326_probe(struct device *parent, |
| 1627 | const char *name, |
| 1628 | int irq, |
| 1629 | unsigned int hwid, |
| 1630 | struct regmap *regmap) |
| 1631 | { |
| 1632 | struct iio_dev *indio_dev; |
| 1633 | struct zpa2326_private *priv; |
| 1634 | int err; |
| 1635 | unsigned int id; |
| 1636 | |
| 1637 | indio_dev = zpa2326_create_managed_iiodev(parent, name, regmap); |
| 1638 | if (!indio_dev) |
| 1639 | return -ENOMEM; |
| 1640 | |
| 1641 | priv = iio_priv(indio_dev); |
| 1642 | |
| 1643 | priv->vref = devm_regulator_get(parent, "vref"); |
| 1644 | if (IS_ERR(priv->vref)) |
| 1645 | return PTR_ERR(priv->vref); |
| 1646 | |
| 1647 | priv->vdd = devm_regulator_get(parent, "vdd"); |
| 1648 | if (IS_ERR(priv->vdd)) |
| 1649 | return PTR_ERR(priv->vdd); |
| 1650 | |
| 1651 | /* Set default hardware sampling frequency to highest rate supported. */ |
| 1652 | priv->frequency = zpa2326_highest_frequency(); |
| 1653 | |
| 1654 | /* |
| 1655 | * Plug device's underlying bus abstraction : this MUST be set before |
| 1656 | * registering interrupt handlers since an interrupt might happen if |
| 1657 | * power up sequence is not properly applied. |
| 1658 | */ |
| 1659 | priv->regmap = regmap; |
| 1660 | |
| 1661 | err = devm_iio_triggered_buffer_setup(parent, indio_dev, NULL, |
| 1662 | zpa2326_trigger_handler, |
| 1663 | &zpa2326_buffer_setup_ops); |
| 1664 | if (err) |
| 1665 | return err; |
| 1666 | |
| 1667 | err = zpa2326_init_managed_trigger(parent, indio_dev, priv, irq); |
| 1668 | if (err) |
| 1669 | return err; |
| 1670 | |
| 1671 | err = zpa2326_init_managed_irq(parent, indio_dev, priv, irq); |
| 1672 | if (err) |
| 1673 | return err; |
| 1674 | |
| 1675 | /* Power up to check device ID and perform initial hardware setup. */ |
| 1676 | err = zpa2326_power_on(indio_dev, priv); |
| 1677 | if (err) |
| 1678 | return err; |
| 1679 | |
| 1680 | /* Read id register to check we are talking to the right slave. */ |
| 1681 | err = regmap_read(regmap, ZPA2326_DEVICE_ID_REG, &id); |
| 1682 | if (err) |
| 1683 | goto sleep; |
| 1684 | |
| 1685 | if (id != hwid) { |
| 1686 | dev_err(parent, "found device with unexpected id %02x", id); |
| 1687 | err = -ENODEV; |
| 1688 | goto sleep; |
| 1689 | } |
| 1690 | |
| 1691 | err = zpa2326_config_oneshot(indio_dev, irq); |
| 1692 | if (err) |
| 1693 | goto sleep; |
| 1694 | |
| 1695 | /* Setup done : go sleeping. Device will be awaken upon user request. */ |
| 1696 | err = zpa2326_sleep(indio_dev); |
| 1697 | if (err) |
| 1698 | goto poweroff; |
| 1699 | |
| 1700 | dev_set_drvdata(parent, indio_dev); |
| 1701 | |
| 1702 | zpa2326_init_runtime(parent); |
| 1703 | |
| 1704 | err = iio_device_register(indio_dev); |
| 1705 | if (err) { |
| 1706 | zpa2326_fini_runtime(parent); |
| 1707 | goto poweroff; |
| 1708 | } |
| 1709 | |
| 1710 | return 0; |
| 1711 | |
| 1712 | sleep: |
| 1713 | /* Put to sleep just in case power regulators are "dummy" ones. */ |
| 1714 | zpa2326_sleep(indio_dev); |
| 1715 | poweroff: |
| 1716 | zpa2326_power_off(indio_dev, priv); |
| 1717 | |
| 1718 | return err; |
| 1719 | } |
| 1720 | EXPORT_SYMBOL_GPL(zpa2326_probe); |
| 1721 | |
| 1722 | void zpa2326_remove(const struct device *parent) |
| 1723 | { |
| 1724 | struct iio_dev *indio_dev = dev_get_drvdata(parent); |
| 1725 | |
| 1726 | iio_device_unregister(indio_dev); |
| 1727 | zpa2326_fini_runtime(indio_dev->dev.parent); |
| 1728 | zpa2326_sleep(indio_dev); |
| 1729 | zpa2326_power_off(indio_dev, iio_priv(indio_dev)); |
| 1730 | } |
| 1731 | EXPORT_SYMBOL_GPL(zpa2326_remove); |
| 1732 | |
| 1733 | MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>"); |
| 1734 | MODULE_DESCRIPTION("Core driver for Murata ZPA2326 pressure sensor"); |
| 1735 | MODULE_LICENSE("GPL v2"); |