adis.c 9.74 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440
/*
 * Common library for ADIS16XXX devices
 *
 * Copyright 2012 Analog Devices Inc.
 *   Author: Lars-Peter Clausen <lars@metafoo.de>
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <asm/unaligned.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/imu/adis.h>

#define ADIS_MSC_CTRL_DATA_RDY_EN	BIT(2)
#define ADIS_MSC_CTRL_DATA_RDY_POL_HIGH	BIT(1)
#define ADIS_MSC_CTRL_DATA_RDY_DIO2	BIT(0)
#define ADIS_GLOB_CMD_SW_RESET		BIT(7)

int adis_write_reg(struct adis *adis, unsigned int reg,
	unsigned int value, unsigned int size)
{
	unsigned int page = reg / ADIS_PAGE_SIZE;
	int ret, i;
	struct spi_message msg;
	struct spi_transfer xfers[] = {
		{
			.tx_buf = adis->tx,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay_usecs = adis->data->write_delay,
		}, {
			.tx_buf = adis->tx + 2,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay_usecs = adis->data->write_delay,
		}, {
			.tx_buf = adis->tx + 4,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay_usecs = adis->data->write_delay,
		}, {
			.tx_buf = adis->tx + 6,
			.bits_per_word = 8,
			.len = 2,
			.delay_usecs = adis->data->write_delay,
		}, {
			.tx_buf = adis->tx + 8,
			.bits_per_word = 8,
			.len = 2,
			.delay_usecs = adis->data->write_delay,
		},
	};

	mutex_lock(&adis->txrx_lock);

	spi_message_init(&msg);

	if (adis->current_page != page) {
		adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
		adis->tx[1] = page;
		spi_message_add_tail(&xfers[0], &msg);
	}

	switch (size) {
	case 4:
		adis->tx[8] = ADIS_WRITE_REG(reg + 3);
		adis->tx[9] = (value >> 24) & 0xff;
		adis->tx[6] = ADIS_WRITE_REG(reg + 2);
		adis->tx[7] = (value >> 16) & 0xff;
	case 2:
		adis->tx[4] = ADIS_WRITE_REG(reg + 1);
		adis->tx[5] = (value >> 8) & 0xff;
	case 1:
		adis->tx[2] = ADIS_WRITE_REG(reg);
		adis->tx[3] = value & 0xff;
		break;
	default:
		ret = -EINVAL;
		goto out_unlock;
	}

	xfers[size].cs_change = 0;

	for (i = 1; i <= size; i++)
		spi_message_add_tail(&xfers[i], &msg);

	ret = spi_sync(adis->spi, &msg);
	if (ret) {
		dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n",
				reg, ret);
	} else {
		adis->current_page = page;
	}

out_unlock:
	mutex_unlock(&adis->txrx_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(adis_write_reg);

/**
 * adis_read_reg() - read 2 bytes from a 16-bit register
 * @adis: The adis device
 * @reg: The address of the lower of the two registers
 * @val: The value read back from the device
 */
int adis_read_reg(struct adis *adis, unsigned int reg,
	unsigned int *val, unsigned int size)
{
	unsigned int page = reg / ADIS_PAGE_SIZE;
	struct spi_message msg;
	int ret;
	struct spi_transfer xfers[] = {
		{
			.tx_buf = adis->tx,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay_usecs = adis->data->write_delay,
		}, {
			.tx_buf = adis->tx + 2,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay_usecs = adis->data->read_delay,
		}, {
			.tx_buf = adis->tx + 4,
			.rx_buf = adis->rx,
			.bits_per_word = 8,
			.len = 2,
			.cs_change = 1,
			.delay_usecs = adis->data->read_delay,
		}, {
			.rx_buf = adis->rx + 2,
			.bits_per_word = 8,
			.len = 2,
			.delay_usecs = adis->data->read_delay,
		},
	};

	mutex_lock(&adis->txrx_lock);
	spi_message_init(&msg);

	if (adis->current_page != page) {
		adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
		adis->tx[1] = page;
		spi_message_add_tail(&xfers[0], &msg);
	}

	switch (size) {
	case 4:
		adis->tx[2] = ADIS_READ_REG(reg + 2);
		adis->tx[3] = 0;
		spi_message_add_tail(&xfers[1], &msg);
	case 2:
		adis->tx[4] = ADIS_READ_REG(reg);
		adis->tx[5] = 0;
		spi_message_add_tail(&xfers[2], &msg);
		spi_message_add_tail(&xfers[3], &msg);
		break;
	default:
		ret = -EINVAL;
		goto out_unlock;
	}

	ret = spi_sync(adis->spi, &msg);
	if (ret) {
		dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
				reg, ret);
		goto out_unlock;
	} else {
		adis->current_page = page;
	}

	switch (size) {
	case 4:
		*val = get_unaligned_be32(adis->rx);
		break;
	case 2:
		*val = get_unaligned_be16(adis->rx + 2);
		break;
	}

out_unlock:
	mutex_unlock(&adis->txrx_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(adis_read_reg);

#ifdef CONFIG_DEBUG_FS

int adis_debugfs_reg_access(struct iio_dev *indio_dev,
	unsigned int reg, unsigned int writeval, unsigned int *readval)
{
	struct adis *adis = iio_device_get_drvdata(indio_dev);

	if (readval) {
		uint16_t val16;
		int ret;

		ret = adis_read_reg_16(adis, reg, &val16);
		*readval = val16;

		return ret;
	} else {
		return adis_write_reg_16(adis, reg, writeval);
	}
}
EXPORT_SYMBOL(adis_debugfs_reg_access);

#endif

/**
 * adis_enable_irq() - Enable or disable data ready IRQ
 * @adis: The adis device
 * @enable: Whether to enable the IRQ
 *
 * Returns 0 on success, negative error code otherwise
 */
int adis_enable_irq(struct adis *adis, bool enable)
{
	int ret = 0;
	uint16_t msc;

	if (adis->data->enable_irq)
		return adis->data->enable_irq(adis, enable);

	ret = adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
	if (ret)
		goto error_ret;

	msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH;
	msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2;
	if (enable)
		msc |= ADIS_MSC_CTRL_DATA_RDY_EN;
	else
		msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;

	ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);

error_ret:
	return ret;
}
EXPORT_SYMBOL(adis_enable_irq);

/**
 * adis_check_status() - Check the device for error conditions
 * @adis: The adis device
 *
 * Returns 0 on success, a negative error code otherwise
 */
int adis_check_status(struct adis *adis)
{
	uint16_t status;
	int ret;
	int i;

	ret = adis_read_reg_16(adis, adis->data->diag_stat_reg, &status);
	if (ret < 0)
		return ret;

	status &= adis->data->status_error_mask;

	if (status == 0)
		return 0;

	for (i = 0; i < 16; ++i) {
		if (status & BIT(i)) {
			dev_err(&adis->spi->dev, "%s.\n",
				adis->data->status_error_msgs[i]);
		}
	}

	return -EIO;
}
EXPORT_SYMBOL_GPL(adis_check_status);

/**
 * adis_reset() - Reset the device
 * @adis: The adis device
 *
 * Returns 0 on success, a negative error code otherwise
 */
int adis_reset(struct adis *adis)
{
	int ret;

	ret = adis_write_reg_8(adis, adis->data->glob_cmd_reg,
			ADIS_GLOB_CMD_SW_RESET);
	if (ret)
		dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret);

	return ret;
}
EXPORT_SYMBOL_GPL(adis_reset);

static int adis_self_test(struct adis *adis)
{
	int ret;

	ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg,
			adis->data->self_test_mask);
	if (ret) {
		dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n",
			ret);
		return ret;
	}

	msleep(adis->data->startup_delay);

	return adis_check_status(adis);
}

/**
 * adis_inital_startup() - Performs device self-test
 * @adis: The adis device
 *
 * Returns 0 if the device is operational, a negative error code otherwise.
 *
 * This function should be called early on in the device initialization sequence
 * to ensure that the device is in a sane and known state and that it is usable.
 */
int adis_initial_startup(struct adis *adis)
{
	int ret;

	ret = adis_self_test(adis);
	if (ret) {
		dev_err(&adis->spi->dev, "Self-test failed, trying reset.\n");
		adis_reset(adis);
		msleep(adis->data->startup_delay);
		ret = adis_self_test(adis);
		if (ret) {
			dev_err(&adis->spi->dev, "Second self-test failed, giving up.\n");
			return ret;
		}
	}

	return 0;
}
EXPORT_SYMBOL_GPL(adis_initial_startup);

/**
 * adis_single_conversion() - Performs a single sample conversion
 * @indio_dev: The IIO device
 * @chan: The IIO channel
 * @error_mask: Mask for the error bit
 * @val: Result of the conversion
 *
 * Returns IIO_VAL_INT on success, a negative error code otherwise.
 *
 * The function performs a single conversion on a given channel and post
 * processes the value accordingly to the channel spec. If a error_mask is given
 * the function will check if the mask is set in the returned raw value. If it
 * is set the function will perform a self-check. If the device does not report
 * a error bit in the channels raw value set error_mask to 0.
 */
int adis_single_conversion(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan, unsigned int error_mask, int *val)
{
	struct adis *adis = iio_device_get_drvdata(indio_dev);
	unsigned int uval;
	int ret;

	mutex_lock(&indio_dev->mlock);

	ret = adis_read_reg(adis, chan->address, &uval,
			chan->scan_type.storagebits / 8);
	if (ret)
		goto err_unlock;

	if (uval & error_mask) {
		ret = adis_check_status(adis);
		if (ret)
			goto err_unlock;
	}

	if (chan->scan_type.sign == 's')
		*val = sign_extend32(uval, chan->scan_type.realbits - 1);
	else
		*val = uval & ((1 << chan->scan_type.realbits) - 1);

	ret = IIO_VAL_INT;
err_unlock:
	mutex_unlock(&indio_dev->mlock);
	return ret;
}
EXPORT_SYMBOL_GPL(adis_single_conversion);

/**
 * adis_init() - Initialize adis device structure
 * @adis:	The adis device
 * @indio_dev:	The iio device
 * @spi:	The spi device
 * @data:	Chip specific data
 *
 * Returns 0 on success, a negative error code otherwise.
 *
 * This function must be called, before any other adis helper function may be
 * called.
 */
int adis_init(struct adis *adis, struct iio_dev *indio_dev,
	struct spi_device *spi, const struct adis_data *data)
{
	mutex_init(&adis->txrx_lock);
	adis->spi = spi;
	adis->data = data;
	iio_device_set_drvdata(indio_dev, adis);

	if (data->has_paging) {
		/* Need to set the page before first read/write */
		adis->current_page = -1;
	} else {
		/* Page will always be 0 */
		adis->current_page = 0;
	}

	return adis_enable_irq(adis, false);
}
EXPORT_SYMBOL_GPL(adis_init);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Common library code for ADIS16XXX devices");