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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * sca3000_core.c -- support VTI sca3000 series accelerometers via SPI4 *5 * Copyright (c) 2009 Jonathan Cameron <jic23@kernel.org>6 *7 * See industrialio/accels/sca3000.h for comments.8 */9 10#include <linux/interrupt.h>11#include <linux/fs.h>12#include <linux/device.h>13#include <linux/slab.h>14#include <linux/kernel.h>15#include <linux/spi/spi.h>16#include <linux/sysfs.h>17#include <linux/module.h>18#include <linux/uaccess.h>19#include <linux/iio/iio.h>20#include <linux/iio/sysfs.h>21#include <linux/iio/events.h>22#include <linux/iio/buffer.h>23#include <linux/iio/kfifo_buf.h>24 25#define SCA3000_WRITE_REG(a) (((a) << 2) | 0x02)26#define SCA3000_READ_REG(a) ((a) << 2)27 28#define SCA3000_REG_REVID_ADDR				0x0029#define   SCA3000_REG_REVID_MAJOR_MASK			GENMASK(8, 4)30#define   SCA3000_REG_REVID_MINOR_MASK			GENMASK(3, 0)31 32#define SCA3000_REG_STATUS_ADDR				0x0233#define   SCA3000_LOCKED				BIT(5)34#define   SCA3000_EEPROM_CS_ERROR			BIT(1)35#define   SCA3000_SPI_FRAME_ERROR			BIT(0)36 37/* All reads done using register decrement so no need to directly access LSBs */38#define SCA3000_REG_X_MSB_ADDR				0x0539#define SCA3000_REG_Y_MSB_ADDR				0x0740#define SCA3000_REG_Z_MSB_ADDR				0x0941 42#define SCA3000_REG_RING_OUT_ADDR			0x0f43 44/* Temp read untested - the e05 doesn't have the sensor */45#define SCA3000_REG_TEMP_MSB_ADDR			0x1346 47#define SCA3000_REG_MODE_ADDR				0x1448#define SCA3000_MODE_PROT_MASK				0x2849#define   SCA3000_REG_MODE_RING_BUF_ENABLE		BIT(7)50#define   SCA3000_REG_MODE_RING_BUF_8BIT		BIT(6)51 52/*53 * Free fall detection triggers an interrupt if the acceleration54 * is below a threshold for equivalent of 25cm drop55 */56#define   SCA3000_REG_MODE_FREE_FALL_DETECT		BIT(4)57#define   SCA3000_REG_MODE_MEAS_MODE_NORMAL		0x0058#define   SCA3000_REG_MODE_MEAS_MODE_OP_1		0x0159#define   SCA3000_REG_MODE_MEAS_MODE_OP_2		0x0260 61/*62 * In motion detection mode the accelerations are band pass filtered63 * (approx 1 - 25Hz) and then a programmable threshold used to trigger64 * and interrupt.65 */66#define   SCA3000_REG_MODE_MEAS_MODE_MOT_DET		0x0367#define   SCA3000_REG_MODE_MODE_MASK			0x0368 69#define SCA3000_REG_BUF_COUNT_ADDR			0x1570 71#define SCA3000_REG_INT_STATUS_ADDR			0x1672#define   SCA3000_REG_INT_STATUS_THREE_QUARTERS		BIT(7)73#define   SCA3000_REG_INT_STATUS_HALF			BIT(6)74 75#define SCA3000_INT_STATUS_FREE_FALL			BIT(3)76#define SCA3000_INT_STATUS_Y_TRIGGER			BIT(2)77#define SCA3000_INT_STATUS_X_TRIGGER			BIT(1)78#define SCA3000_INT_STATUS_Z_TRIGGER			BIT(0)79 80/* Used to allow access to multiplexed registers */81#define SCA3000_REG_CTRL_SEL_ADDR			0x1882/* Only available for SCA3000-D03 and SCA3000-D01 */83#define   SCA3000_REG_CTRL_SEL_I2C_DISABLE		0x0184#define   SCA3000_REG_CTRL_SEL_MD_CTRL			0x0285#define   SCA3000_REG_CTRL_SEL_MD_Y_TH			0x0386#define   SCA3000_REG_CTRL_SEL_MD_X_TH			0x0487#define   SCA3000_REG_CTRL_SEL_MD_Z_TH			0x0588/*89 * BE VERY CAREFUL WITH THIS, IF 3 BITS ARE NOT SET the device90 * will not function91 */92#define   SCA3000_REG_CTRL_SEL_OUT_CTRL			0x0B93 94#define     SCA3000_REG_OUT_CTRL_PROT_MASK		0xE095#define     SCA3000_REG_OUT_CTRL_BUF_X_EN		0x1096#define     SCA3000_REG_OUT_CTRL_BUF_Y_EN		0x0897#define     SCA3000_REG_OUT_CTRL_BUF_Z_EN		0x0498#define     SCA3000_REG_OUT_CTRL_BUF_DIV_MASK		0x0399#define     SCA3000_REG_OUT_CTRL_BUF_DIV_4		0x02100#define     SCA3000_REG_OUT_CTRL_BUF_DIV_2		0x01101 102 103/*104 * Control which motion detector interrupts are on.105 * For now only OR combinations are supported.106 */107#define SCA3000_MD_CTRL_PROT_MASK			0xC0108#define SCA3000_MD_CTRL_OR_Y				BIT(0)109#define SCA3000_MD_CTRL_OR_X				BIT(1)110#define SCA3000_MD_CTRL_OR_Z				BIT(2)111/* Currently unsupported */112#define SCA3000_MD_CTRL_AND_Y				BIT(3)113#define SCA3000_MD_CTRL_AND_X				BIT(4)114#define SCA3000_MD_CTRL_AND_Z				BIT(5)115 116/*117 * Some control registers of complex access methods requiring this register to118 * be used to remove a lock.119 */120#define SCA3000_REG_UNLOCK_ADDR				0x1e121 122#define SCA3000_REG_INT_MASK_ADDR			0x21123#define   SCA3000_REG_INT_MASK_PROT_MASK		0x1C124 125#define   SCA3000_REG_INT_MASK_RING_THREE_QUARTER	BIT(7)126#define   SCA3000_REG_INT_MASK_RING_HALF		BIT(6)127 128#define SCA3000_REG_INT_MASK_ALL_INTS			0x02129#define SCA3000_REG_INT_MASK_ACTIVE_HIGH		0x01130#define SCA3000_REG_INT_MASK_ACTIVE_LOW			0x00131/* Values of multiplexed registers (write to ctrl_data after select) */132#define SCA3000_REG_CTRL_DATA_ADDR			0x22133 134/*135 * Measurement modes available on some sca3000 series chips. Code assumes others136 * may become available in the future.137 *138 * Bypass - Bypass the low-pass filter in the signal channel so as to increase139 *          signal bandwidth.140 *141 * Narrow - Narrow low-pass filtering of the signal channel and half output142 *          data rate by decimation.143 *144 * Wide - Widen low-pass filtering of signal channel to increase bandwidth145 */146#define SCA3000_OP_MODE_BYPASS				0x01147#define SCA3000_OP_MODE_NARROW				0x02148#define SCA3000_OP_MODE_WIDE				0x04149#define SCA3000_MAX_TX 6150#define SCA3000_MAX_RX 2151 152/**153 * struct sca3000_state - device instance state information154 * @us:			the associated spi device155 * @info:			chip variant information156 * @last_timestamp:		the timestamp of the last event157 * @mo_det_use_count:		reference counter for the motion detection unit158 * @lock:			lock used to protect elements of sca3000_state159 *				and the underlying device state.160 * @tx:			dma-able transmit buffer161 * @rx:			dma-able receive buffer162 **/163struct sca3000_state {164	struct spi_device		*us;165	const struct sca3000_chip_info	*info;166	s64				last_timestamp;167	int				mo_det_use_count;168	struct mutex			lock;169	/* Can these share a cacheline ? */170	u8				rx[384] __aligned(IIO_DMA_MINALIGN);171	u8				tx[6] __aligned(IIO_DMA_MINALIGN);172};173 174/**175 * struct sca3000_chip_info - model dependent parameters176 * @scale:			scale * 10^-6177 * @temp_output:		some devices have temperature sensors.178 * @measurement_mode_freq:	normal mode sampling frequency179 * @measurement_mode_3db_freq:	3db cutoff frequency of the low pass filter for180 * the normal measurement mode.181 * @option_mode_1:		first optional mode. Not all models have one182 * @option_mode_1_freq:		option mode 1 sampling frequency183 * @option_mode_1_3db_freq:	3db cutoff frequency of the low pass filter for184 * the first option mode.185 * @option_mode_2:		second optional mode. Not all chips have one186 * @option_mode_2_freq:		option mode 2 sampling frequency187 * @option_mode_2_3db_freq:	3db cutoff frequency of the low pass filter for188 * the second option mode.189 * @mot_det_mult_xz:		Bit wise multipliers to calculate the threshold190 * for motion detection in the x and z axis.191 * @mot_det_mult_y:		Bit wise multipliers to calculate the threshold192 * for motion detection in the y axis.193 *194 * This structure is used to hold information about the functionality of a given195 * sca3000 variant.196 **/197struct sca3000_chip_info {198	unsigned int		scale;199	bool			temp_output;200	int			measurement_mode_freq;201	int			measurement_mode_3db_freq;202	int			option_mode_1;203	int			option_mode_1_freq;204	int			option_mode_1_3db_freq;205	int			option_mode_2;206	int			option_mode_2_freq;207	int			option_mode_2_3db_freq;208	int			mot_det_mult_xz[6];209	int			mot_det_mult_y[7];210};211 212enum sca3000_variant {213	d01,214	e02,215	e04,216	e05,217};218 219/*220 * Note where option modes are not defined, the chip simply does not221 * support any.222 * Other chips in the sca3000 series use i2c and are not included here.223 *224 * Some of these devices are only listed in the family data sheet and225 * do not actually appear to be available.226 */227static const struct sca3000_chip_info sca3000_spi_chip_info_tbl[] = {228	[d01] = {229		.scale = 7357,230		.temp_output = true,231		.measurement_mode_freq = 250,232		.measurement_mode_3db_freq = 45,233		.option_mode_1 = SCA3000_OP_MODE_BYPASS,234		.option_mode_1_freq = 250,235		.option_mode_1_3db_freq = 70,236		.mot_det_mult_xz = {50, 100, 200, 350, 650, 1300},237		.mot_det_mult_y = {50, 100, 150, 250, 450, 850, 1750},238	},239	[e02] = {240		.scale = 9810,241		.measurement_mode_freq = 125,242		.measurement_mode_3db_freq = 40,243		.option_mode_1 = SCA3000_OP_MODE_NARROW,244		.option_mode_1_freq = 63,245		.option_mode_1_3db_freq = 11,246		.mot_det_mult_xz = {100, 150, 300, 550, 1050, 2050},247		.mot_det_mult_y = {50, 100, 200, 350, 700, 1350, 2700},248	},249	[e04] = {250		.scale = 19620,251		.measurement_mode_freq = 100,252		.measurement_mode_3db_freq = 38,253		.option_mode_1 = SCA3000_OP_MODE_NARROW,254		.option_mode_1_freq = 50,255		.option_mode_1_3db_freq = 9,256		.option_mode_2 = SCA3000_OP_MODE_WIDE,257		.option_mode_2_freq = 400,258		.option_mode_2_3db_freq = 70,259		.mot_det_mult_xz = {200, 300, 600, 1100, 2100, 4100},260		.mot_det_mult_y = {100, 200, 400, 7000, 1400, 2700, 54000},261	},262	[e05] = {263		.scale = 61313,264		.measurement_mode_freq = 200,265		.measurement_mode_3db_freq = 60,266		.option_mode_1 = SCA3000_OP_MODE_NARROW,267		.option_mode_1_freq = 50,268		.option_mode_1_3db_freq = 9,269		.option_mode_2 = SCA3000_OP_MODE_WIDE,270		.option_mode_2_freq = 400,271		.option_mode_2_3db_freq = 75,272		.mot_det_mult_xz = {600, 900, 1700, 3200, 6100, 11900},273		.mot_det_mult_y = {300, 600, 1200, 2000, 4100, 7800, 15600},274	},275};276 277static int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val)278{279	st->tx[0] = SCA3000_WRITE_REG(address);280	st->tx[1] = val;281	return spi_write(st->us, st->tx, 2);282}283 284static int sca3000_read_data_short(struct sca3000_state *st,285				   u8 reg_address_high,286				   int len)287{288	struct spi_transfer xfer[2] = {289		{290			.len = 1,291			.tx_buf = st->tx,292		}, {293			.len = len,294			.rx_buf = st->rx,295		}296	};297	st->tx[0] = SCA3000_READ_REG(reg_address_high);298 299	return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));300}301 302/**303 * sca3000_reg_lock_on() - test if the ctrl register lock is on304 * @st: Driver specific device instance data.305 *306 * Lock must be held.307 **/308static int sca3000_reg_lock_on(struct sca3000_state *st)309{310	int ret;311 312	ret = sca3000_read_data_short(st, SCA3000_REG_STATUS_ADDR, 1);313	if (ret < 0)314		return ret;315 316	return !(st->rx[0] & SCA3000_LOCKED);317}318 319/**320 * __sca3000_unlock_reg_lock() - unlock the control registers321 * @st: Driver specific device instance data.322 *323 * Note the device does not appear to support doing this in a single transfer.324 * This should only ever be used as part of ctrl reg read.325 * Lock must be held before calling this326 */327static int __sca3000_unlock_reg_lock(struct sca3000_state *st)328{329	struct spi_transfer xfer[3] = {330		{331			.len = 2,332			.cs_change = 1,333			.tx_buf = st->tx,334		}, {335			.len = 2,336			.cs_change = 1,337			.tx_buf = st->tx + 2,338		}, {339			.len = 2,340			.tx_buf = st->tx + 4,341		},342	};343	st->tx[0] = SCA3000_WRITE_REG(SCA3000_REG_UNLOCK_ADDR);344	st->tx[1] = 0x00;345	st->tx[2] = SCA3000_WRITE_REG(SCA3000_REG_UNLOCK_ADDR);346	st->tx[3] = 0x50;347	st->tx[4] = SCA3000_WRITE_REG(SCA3000_REG_UNLOCK_ADDR);348	st->tx[5] = 0xA0;349 350	return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));351}352 353/**354 * sca3000_write_ctrl_reg() - write to a lock protect ctrl register355 * @st: Driver specific device instance data.356 * @sel: selects which registers we wish to write to357 * @val: the value to be written358 *359 * Certain control registers are protected against overwriting by the lock360 * register and use a shared write address. This function allows writing of361 * these registers.362 * Lock must be held.363 */364static int sca3000_write_ctrl_reg(struct sca3000_state *st,365				  u8 sel,366				  uint8_t val)367{368	int ret;369 370	ret = sca3000_reg_lock_on(st);371	if (ret < 0)372		goto error_ret;373	if (ret) {374		ret = __sca3000_unlock_reg_lock(st);375		if (ret)376			goto error_ret;377	}378 379	/* Set the control select register */380	ret = sca3000_write_reg(st, SCA3000_REG_CTRL_SEL_ADDR, sel);381	if (ret)382		goto error_ret;383 384	/* Write the actual value into the register */385	ret = sca3000_write_reg(st, SCA3000_REG_CTRL_DATA_ADDR, val);386 387error_ret:388	return ret;389}390 391/**392 * sca3000_read_ctrl_reg() - read from lock protected control register.393 * @st: Driver specific device instance data.394 * @ctrl_reg: Which ctrl register do we want to read.395 *396 * Lock must be held.397 */398static int sca3000_read_ctrl_reg(struct sca3000_state *st,399				 u8 ctrl_reg)400{401	int ret;402 403	ret = sca3000_reg_lock_on(st);404	if (ret < 0)405		goto error_ret;406	if (ret) {407		ret = __sca3000_unlock_reg_lock(st);408		if (ret)409			goto error_ret;410	}411	/* Set the control select register */412	ret = sca3000_write_reg(st, SCA3000_REG_CTRL_SEL_ADDR, ctrl_reg);413	if (ret)414		goto error_ret;415	ret = sca3000_read_data_short(st, SCA3000_REG_CTRL_DATA_ADDR, 1);416	if (ret)417		goto error_ret;418	return st->rx[0];419error_ret:420	return ret;421}422 423/**424 * sca3000_print_rev() - sysfs interface to read the chip revision number425 * @indio_dev: Device instance specific generic IIO data.426 * Driver specific device instance data can be obtained via427 * iio_priv(indio_dev)428 */429static int sca3000_print_rev(struct iio_dev *indio_dev)430{431	int ret;432	struct sca3000_state *st = iio_priv(indio_dev);433 434	mutex_lock(&st->lock);435	ret = sca3000_read_data_short(st, SCA3000_REG_REVID_ADDR, 1);436	if (ret < 0)437		goto error_ret;438	dev_info(&indio_dev->dev,439		 "sca3000 revision major=%lu, minor=%lu\n",440		 st->rx[0] & SCA3000_REG_REVID_MAJOR_MASK,441		 st->rx[0] & SCA3000_REG_REVID_MINOR_MASK);442error_ret:443	mutex_unlock(&st->lock);444 445	return ret;446}447 448static ssize_t449sca3000_show_available_3db_freqs(struct device *dev,450				 struct device_attribute *attr,451				 char *buf)452{453	struct iio_dev *indio_dev = dev_to_iio_dev(dev);454	struct sca3000_state *st = iio_priv(indio_dev);455	int len;456 457	len = sprintf(buf, "%d", st->info->measurement_mode_3db_freq);458	if (st->info->option_mode_1)459		len += sprintf(buf + len, " %d",460			       st->info->option_mode_1_3db_freq);461	if (st->info->option_mode_2)462		len += sprintf(buf + len, " %d",463			       st->info->option_mode_2_3db_freq);464	len += sprintf(buf + len, "\n");465 466	return len;467}468 469static IIO_DEVICE_ATTR(in_accel_filter_low_pass_3db_frequency_available,470		       S_IRUGO, sca3000_show_available_3db_freqs,471		       NULL, 0);472 473static const struct iio_event_spec sca3000_event = {474	.type = IIO_EV_TYPE_MAG,475	.dir = IIO_EV_DIR_RISING,476	.mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),477};478 479/*480 * Note the hack in the number of bits to pretend we have 2 more than481 * we do in the fifo.482 */483#define SCA3000_CHAN(index, mod)				\484	{							\485		.type = IIO_ACCEL,				\486		.modified = 1,					\487		.channel2 = mod,				\488		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\489		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |\490			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),\491		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\492		.address = index,				\493		.scan_index = index,				\494		.scan_type = {					\495			.sign = 's',				\496			.realbits = 13,				\497			.storagebits = 16,			\498			.shift = 3,				\499			.endianness = IIO_BE,			\500		},						\501		.event_spec = &sca3000_event,			\502		.num_event_specs = 1,				\503	}504 505static const struct iio_event_spec sca3000_freefall_event_spec = {506	.type = IIO_EV_TYPE_MAG,507	.dir = IIO_EV_DIR_FALLING,508	.mask_separate = BIT(IIO_EV_INFO_ENABLE) |509		BIT(IIO_EV_INFO_PERIOD),510};511 512static const struct iio_chan_spec sca3000_channels[] = {513	SCA3000_CHAN(0, IIO_MOD_X),514	SCA3000_CHAN(1, IIO_MOD_Y),515	SCA3000_CHAN(2, IIO_MOD_Z),516	{517		.type = IIO_ACCEL,518		.modified = 1,519		.channel2 = IIO_MOD_X_AND_Y_AND_Z,520		.scan_index = -1, /* Fake channel */521		.event_spec = &sca3000_freefall_event_spec,522		.num_event_specs = 1,523	},524};525 526static const struct iio_chan_spec sca3000_channels_with_temp[] = {527	SCA3000_CHAN(0, IIO_MOD_X),528	SCA3000_CHAN(1, IIO_MOD_Y),529	SCA3000_CHAN(2, IIO_MOD_Z),530	{531		.type = IIO_TEMP,532		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),533		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |534			BIT(IIO_CHAN_INFO_OFFSET),535		/* No buffer support */536		.scan_index = -1,537		.scan_type = {538			.sign = 'u',539			.realbits = 9,540			.storagebits = 16,541			.shift = 5,542			.endianness = IIO_BE,543		},544	},545	{546		.type = IIO_ACCEL,547		.modified = 1,548		.channel2 = IIO_MOD_X_AND_Y_AND_Z,549		.scan_index = -1, /* Fake channel */550		.event_spec = &sca3000_freefall_event_spec,551		.num_event_specs = 1,552	},553};554 555static u8 sca3000_addresses[3][3] = {556	[0] = {SCA3000_REG_X_MSB_ADDR, SCA3000_REG_CTRL_SEL_MD_X_TH,557	       SCA3000_MD_CTRL_OR_X},558	[1] = {SCA3000_REG_Y_MSB_ADDR, SCA3000_REG_CTRL_SEL_MD_Y_TH,559	       SCA3000_MD_CTRL_OR_Y},560	[2] = {SCA3000_REG_Z_MSB_ADDR, SCA3000_REG_CTRL_SEL_MD_Z_TH,561	       SCA3000_MD_CTRL_OR_Z},562};563 564/**565 * __sca3000_get_base_freq() - obtain mode specific base frequency566 * @st: Private driver specific device instance specific state.567 * @info: chip type specific information.568 * @base_freq: Base frequency for the current measurement mode.569 *570 * lock must be held571 */572static inline int __sca3000_get_base_freq(struct sca3000_state *st,573					  const struct sca3000_chip_info *info,574					  int *base_freq)575{576	int ret;577 578	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);579	if (ret)580		goto error_ret;581	switch (SCA3000_REG_MODE_MODE_MASK & st->rx[0]) {582	case SCA3000_REG_MODE_MEAS_MODE_NORMAL:583		*base_freq = info->measurement_mode_freq;584		break;585	case SCA3000_REG_MODE_MEAS_MODE_OP_1:586		*base_freq = info->option_mode_1_freq;587		break;588	case SCA3000_REG_MODE_MEAS_MODE_OP_2:589		*base_freq = info->option_mode_2_freq;590		break;591	default:592		ret = -EINVAL;593	}594error_ret:595	return ret;596}597 598/**599 * sca3000_read_raw_samp_freq() - read_raw handler for IIO_CHAN_INFO_SAMP_FREQ600 * @st: Private driver specific device instance specific state.601 * @val: The frequency read back.602 *603 * lock must be held604 **/605static int sca3000_read_raw_samp_freq(struct sca3000_state *st, int *val)606{607	int ret;608 609	ret = __sca3000_get_base_freq(st, st->info, val);610	if (ret)611		return ret;612 613	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);614	if (ret < 0)615		return ret;616 617	if (*val > 0) {618		ret &= SCA3000_REG_OUT_CTRL_BUF_DIV_MASK;619		switch (ret) {620		case SCA3000_REG_OUT_CTRL_BUF_DIV_2:621			*val /= 2;622			break;623		case SCA3000_REG_OUT_CTRL_BUF_DIV_4:624			*val /= 4;625			break;626		}627	}628 629	return 0;630}631 632/**633 * sca3000_write_raw_samp_freq() - write_raw handler for IIO_CHAN_INFO_SAMP_FREQ634 * @st: Private driver specific device instance specific state.635 * @val: The frequency desired.636 *637 * lock must be held638 */639static int sca3000_write_raw_samp_freq(struct sca3000_state *st, int val)640{641	int ret, base_freq, ctrlval;642 643	ret = __sca3000_get_base_freq(st, st->info, &base_freq);644	if (ret)645		return ret;646 647	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);648	if (ret < 0)649		return ret;650 651	ctrlval = ret & ~SCA3000_REG_OUT_CTRL_BUF_DIV_MASK;652 653	if (val == base_freq / 2)654		ctrlval |= SCA3000_REG_OUT_CTRL_BUF_DIV_2;655	if (val == base_freq / 4)656		ctrlval |= SCA3000_REG_OUT_CTRL_BUF_DIV_4;657	else if (val != base_freq)658		return -EINVAL;659 660	return sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL,661				     ctrlval);662}663 664static int sca3000_read_3db_freq(struct sca3000_state *st, int *val)665{666	int ret;667 668	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);669	if (ret)670		return ret;671 672	/* mask bottom 2 bits - only ones that are relevant */673	st->rx[0] &= SCA3000_REG_MODE_MODE_MASK;674	switch (st->rx[0]) {675	case SCA3000_REG_MODE_MEAS_MODE_NORMAL:676		*val = st->info->measurement_mode_3db_freq;677		return IIO_VAL_INT;678	case SCA3000_REG_MODE_MEAS_MODE_MOT_DET:679		return -EBUSY;680	case SCA3000_REG_MODE_MEAS_MODE_OP_1:681		*val = st->info->option_mode_1_3db_freq;682		return IIO_VAL_INT;683	case SCA3000_REG_MODE_MEAS_MODE_OP_2:684		*val = st->info->option_mode_2_3db_freq;685		return IIO_VAL_INT;686	default:687		return -EINVAL;688	}689}690 691static int sca3000_write_3db_freq(struct sca3000_state *st, int val)692{693	int ret;694	int mode;695 696	if (val == st->info->measurement_mode_3db_freq)697		mode = SCA3000_REG_MODE_MEAS_MODE_NORMAL;698	else if (st->info->option_mode_1 &&699		 (val == st->info->option_mode_1_3db_freq))700		mode = SCA3000_REG_MODE_MEAS_MODE_OP_1;701	else if (st->info->option_mode_2 &&702		 (val == st->info->option_mode_2_3db_freq))703		mode = SCA3000_REG_MODE_MEAS_MODE_OP_2;704	else705		return -EINVAL;706	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);707	if (ret)708		return ret;709 710	st->rx[0] &= ~SCA3000_REG_MODE_MODE_MASK;711	st->rx[0] |= (mode & SCA3000_REG_MODE_MODE_MASK);712 713	return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, st->rx[0]);714}715 716static int sca3000_read_raw(struct iio_dev *indio_dev,717			    struct iio_chan_spec const *chan,718			    int *val,719			    int *val2,720			    long mask)721{722	struct sca3000_state *st = iio_priv(indio_dev);723	int ret;724	u8 address;725 726	switch (mask) {727	case IIO_CHAN_INFO_RAW:728		mutex_lock(&st->lock);729		if (chan->type == IIO_ACCEL) {730			if (st->mo_det_use_count) {731				mutex_unlock(&st->lock);732				return -EBUSY;733			}734			address = sca3000_addresses[chan->address][0];735			ret = sca3000_read_data_short(st, address, 2);736			if (ret < 0) {737				mutex_unlock(&st->lock);738				return ret;739			}740			*val = sign_extend32(be16_to_cpup((__be16 *)st->rx) >>741					     chan->scan_type.shift,742					     chan->scan_type.realbits - 1);743		} else {744			/* get the temperature when available */745			ret = sca3000_read_data_short(st,746						      SCA3000_REG_TEMP_MSB_ADDR,747						      2);748			if (ret < 0) {749				mutex_unlock(&st->lock);750				return ret;751			}752			*val = (be16_to_cpup((__be16 *)st->rx) >>753				chan->scan_type.shift) &754				GENMASK(chan->scan_type.realbits - 1, 0);755		}756		mutex_unlock(&st->lock);757		return IIO_VAL_INT;758	case IIO_CHAN_INFO_SCALE:759		*val = 0;760		if (chan->type == IIO_ACCEL)761			*val2 = st->info->scale;762		else /* temperature */763			*val2 = 555556;764		return IIO_VAL_INT_PLUS_MICRO;765	case IIO_CHAN_INFO_OFFSET:766		*val = -214;767		*val2 = 600000;768		return IIO_VAL_INT_PLUS_MICRO;769	case IIO_CHAN_INFO_SAMP_FREQ:770		mutex_lock(&st->lock);771		ret = sca3000_read_raw_samp_freq(st, val);772		mutex_unlock(&st->lock);773		return ret ? ret : IIO_VAL_INT;774	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:775		mutex_lock(&st->lock);776		ret = sca3000_read_3db_freq(st, val);777		mutex_unlock(&st->lock);778		return ret;779	default:780		return -EINVAL;781	}782}783 784static int sca3000_write_raw(struct iio_dev *indio_dev,785			     struct iio_chan_spec const *chan,786			     int val, int val2, long mask)787{788	struct sca3000_state *st = iio_priv(indio_dev);789	int ret;790 791	switch (mask) {792	case IIO_CHAN_INFO_SAMP_FREQ:793		if (val2)794			return -EINVAL;795		mutex_lock(&st->lock);796		ret = sca3000_write_raw_samp_freq(st, val);797		mutex_unlock(&st->lock);798		return ret;799	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:800		if (val2)801			return -EINVAL;802		mutex_lock(&st->lock);803		ret = sca3000_write_3db_freq(st, val);804		mutex_unlock(&st->lock);805		return ret;806	default:807		return -EINVAL;808	}809 810	return ret;811}812 813/**814 * sca3000_read_av_freq() - sysfs function to get available frequencies815 * @dev: Device structure for this device.816 * @attr: Description of the attribute.817 * @buf: Incoming string818 *819 * The later modes are only relevant to the ring buffer - and depend on current820 * mode. Note that data sheet gives rather wide tolerances for these so integer821 * division will give good enough answer and not all chips have them specified822 * at all.823 **/824static ssize_t sca3000_read_av_freq(struct device *dev,825				    struct device_attribute *attr,826				    char *buf)827{828	struct iio_dev *indio_dev = dev_to_iio_dev(dev);829	struct sca3000_state *st = iio_priv(indio_dev);830	int len = 0, ret, val;831 832	mutex_lock(&st->lock);833	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);834	val = st->rx[0];835	mutex_unlock(&st->lock);836	if (ret)837		goto error_ret;838 839	switch (val & SCA3000_REG_MODE_MODE_MASK) {840	case SCA3000_REG_MODE_MEAS_MODE_NORMAL:841		len += sprintf(buf + len, "%d %d %d\n",842			       st->info->measurement_mode_freq,843			       st->info->measurement_mode_freq / 2,844			       st->info->measurement_mode_freq / 4);845		break;846	case SCA3000_REG_MODE_MEAS_MODE_OP_1:847		len += sprintf(buf + len, "%d %d %d\n",848			       st->info->option_mode_1_freq,849			       st->info->option_mode_1_freq / 2,850			       st->info->option_mode_1_freq / 4);851		break;852	case SCA3000_REG_MODE_MEAS_MODE_OP_2:853		len += sprintf(buf + len, "%d %d %d\n",854			       st->info->option_mode_2_freq,855			       st->info->option_mode_2_freq / 2,856			       st->info->option_mode_2_freq / 4);857		break;858	}859	return len;860error_ret:861	return ret;862}863 864/*865 * Should only really be registered if ring buffer support is compiled in.866 * Does no harm however and doing it right would add a fair bit of complexity867 */868static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(sca3000_read_av_freq);869 870/*871 * sca3000_read_event_value() - query of a threshold or period872 */873static int sca3000_read_event_value(struct iio_dev *indio_dev,874				    const struct iio_chan_spec *chan,875				    enum iio_event_type type,876				    enum iio_event_direction dir,877				    enum iio_event_info info,878				    int *val, int *val2)879{880	struct sca3000_state *st = iio_priv(indio_dev);881	long ret;882	int i;883 884	switch (info) {885	case IIO_EV_INFO_VALUE:886		mutex_lock(&st->lock);887		ret = sca3000_read_ctrl_reg(st,888					    sca3000_addresses[chan->address][1]);889		mutex_unlock(&st->lock);890		if (ret < 0)891			return ret;892		*val = 0;893		if (chan->channel2 == IIO_MOD_Y)894			for_each_set_bit(i, &ret,895					 ARRAY_SIZE(st->info->mot_det_mult_y))896				*val += st->info->mot_det_mult_y[i];897		else898			for_each_set_bit(i, &ret,899					 ARRAY_SIZE(st->info->mot_det_mult_xz))900				*val += st->info->mot_det_mult_xz[i];901 902		return IIO_VAL_INT;903	case IIO_EV_INFO_PERIOD:904		*val = 0;905		*val2 = 226000;906		return IIO_VAL_INT_PLUS_MICRO;907	default:908		return -EINVAL;909	}910}911 912/**913 * sca3000_write_event_value() - control of threshold and period914 * @indio_dev: Device instance specific IIO information.915 * @chan: Description of the channel for which the event is being916 * configured.917 * @type: The type of event being configured, here magnitude rising918 * as everything else is read only.919 * @dir: Direction of the event (here rising)920 * @info: What information about the event are we configuring.921 * Here the threshold only.922 * @val: Integer part of the value being written..923 * @val2: Non integer part of the value being written. Here always 0.924 */925static int sca3000_write_event_value(struct iio_dev *indio_dev,926				     const struct iio_chan_spec *chan,927				     enum iio_event_type type,928				     enum iio_event_direction dir,929				     enum iio_event_info info,930				     int val, int val2)931{932	struct sca3000_state *st = iio_priv(indio_dev);933	int ret;934	int i;935	u8 nonlinear = 0;936 937	if (chan->channel2 == IIO_MOD_Y) {938		i = ARRAY_SIZE(st->info->mot_det_mult_y);939		while (i > 0)940			if (val >= st->info->mot_det_mult_y[--i]) {941				nonlinear |= (1 << i);942				val -= st->info->mot_det_mult_y[i];943			}944	} else {945		i = ARRAY_SIZE(st->info->mot_det_mult_xz);946		while (i > 0)947			if (val >= st->info->mot_det_mult_xz[--i]) {948				nonlinear |= (1 << i);949				val -= st->info->mot_det_mult_xz[i];950			}951	}952 953	mutex_lock(&st->lock);954	ret = sca3000_write_ctrl_reg(st,955				     sca3000_addresses[chan->address][1],956				     nonlinear);957	mutex_unlock(&st->lock);958 959	return ret;960}961 962static struct attribute *sca3000_attributes[] = {963	&iio_dev_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr,964	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,965	NULL,966};967 968static const struct attribute_group sca3000_attribute_group = {969	.attrs = sca3000_attributes,970};971 972static int sca3000_read_data(struct sca3000_state *st,973			     u8 reg_address_high,974			     u8 *rx,975			     int len)976{977	int ret;978	struct spi_transfer xfer[2] = {979		{980			.len = 1,981			.tx_buf = st->tx,982		}, {983			.len = len,984			.rx_buf = rx,985		}986	};987 988	st->tx[0] = SCA3000_READ_REG(reg_address_high);989	ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer));990	if (ret) {991		dev_err(&st->us->dev, "problem reading register\n");992		return ret;993	}994 995	return 0;996}997 998/**999 * sca3000_ring_int_process() - ring specific interrupt handling.1000 * @val: Value of the interrupt status register.1001 * @indio_dev: Device instance specific IIO device structure.1002 */1003static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)1004{1005	struct sca3000_state *st = iio_priv(indio_dev);1006	int ret, i, num_available;1007 1008	mutex_lock(&st->lock);1009 1010	if (val & SCA3000_REG_INT_STATUS_HALF) {1011		ret = sca3000_read_data_short(st, SCA3000_REG_BUF_COUNT_ADDR,1012					      1);1013		if (ret)1014			goto error_ret;1015		num_available = st->rx[0];1016		/*1017		 * num_available is the total number of samples available1018		 * i.e. number of time points * number of channels.1019		 */1020		ret = sca3000_read_data(st, SCA3000_REG_RING_OUT_ADDR, st->rx,1021					num_available * 2);1022		if (ret)1023			goto error_ret;1024		for (i = 0; i < num_available / 3; i++) {1025			/*1026			 * Dirty hack to cover for 11 bit in fifo, 13 bit1027			 * direct reading.1028			 *1029			 * In theory the bottom two bits are undefined.1030			 * In reality they appear to always be 0.1031			 */1032			iio_push_to_buffers(indio_dev, st->rx + i * 3 * 2);1033		}1034	}1035error_ret:1036	mutex_unlock(&st->lock);1037}1038 1039/**1040 * sca3000_event_handler() - handling ring and non ring events1041 * @irq: The irq being handled.1042 * @private: struct iio_device pointer for the device.1043 *1044 * Ring related interrupt handler. Depending on event, push to1045 * the ring buffer event chrdev or the event one.1046 *1047 * This function is complicated by the fact that the devices can signify ring1048 * and non ring events via the same interrupt line and they can only1049 * be distinguished via a read of the relevant status register.1050 */1051static irqreturn_t sca3000_event_handler(int irq, void *private)1052{1053	struct iio_dev *indio_dev = private;1054	struct sca3000_state *st = iio_priv(indio_dev);1055	int ret, val;1056	s64 last_timestamp = iio_get_time_ns(indio_dev);1057 1058	/*1059	 * Could lead if badly timed to an extra read of status reg,1060	 * but ensures no interrupt is missed.1061	 */1062	mutex_lock(&st->lock);1063	ret = sca3000_read_data_short(st, SCA3000_REG_INT_STATUS_ADDR, 1);1064	val = st->rx[0];1065	mutex_unlock(&st->lock);1066	if (ret)1067		goto done;1068 1069	sca3000_ring_int_process(val, indio_dev);1070 1071	if (val & SCA3000_INT_STATUS_FREE_FALL)1072		iio_push_event(indio_dev,1073			       IIO_MOD_EVENT_CODE(IIO_ACCEL,1074						  0,1075						  IIO_MOD_X_AND_Y_AND_Z,1076						  IIO_EV_TYPE_MAG,1077						  IIO_EV_DIR_FALLING),1078			       last_timestamp);1079 1080	if (val & SCA3000_INT_STATUS_Y_TRIGGER)1081		iio_push_event(indio_dev,1082			       IIO_MOD_EVENT_CODE(IIO_ACCEL,1083						  0,1084						  IIO_MOD_Y,1085						  IIO_EV_TYPE_MAG,1086						  IIO_EV_DIR_RISING),1087			       last_timestamp);1088 1089	if (val & SCA3000_INT_STATUS_X_TRIGGER)1090		iio_push_event(indio_dev,1091			       IIO_MOD_EVENT_CODE(IIO_ACCEL,1092						  0,1093						  IIO_MOD_X,1094						  IIO_EV_TYPE_MAG,1095						  IIO_EV_DIR_RISING),1096			       last_timestamp);1097 1098	if (val & SCA3000_INT_STATUS_Z_TRIGGER)1099		iio_push_event(indio_dev,1100			       IIO_MOD_EVENT_CODE(IIO_ACCEL,1101						  0,1102						  IIO_MOD_Z,1103						  IIO_EV_TYPE_MAG,1104						  IIO_EV_DIR_RISING),1105			       last_timestamp);1106 1107done:1108	return IRQ_HANDLED;1109}1110 1111/*1112 * sca3000_read_event_config() what events are enabled1113 */1114static int sca3000_read_event_config(struct iio_dev *indio_dev,1115				     const struct iio_chan_spec *chan,1116				     enum iio_event_type type,1117				     enum iio_event_direction dir)1118{1119	struct sca3000_state *st = iio_priv(indio_dev);1120	int ret;1121	/* read current value of mode register */1122	mutex_lock(&st->lock);1123 1124	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);1125	if (ret)1126		goto error_ret;1127 1128	switch (chan->channel2) {1129	case IIO_MOD_X_AND_Y_AND_Z:1130		ret = !!(st->rx[0] & SCA3000_REG_MODE_FREE_FALL_DETECT);1131		break;1132	case IIO_MOD_X:1133	case IIO_MOD_Y:1134	case IIO_MOD_Z:1135		/*1136		 * Motion detection mode cannot run at the same time as1137		 * acceleration data being read.1138		 */1139		if ((st->rx[0] & SCA3000_REG_MODE_MODE_MASK)1140		    != SCA3000_REG_MODE_MEAS_MODE_MOT_DET) {1141			ret = 0;1142		} else {1143			ret = sca3000_read_ctrl_reg(st,1144						SCA3000_REG_CTRL_SEL_MD_CTRL);1145			if (ret < 0)1146				goto error_ret;1147			/* only supporting logical or's for now */1148			ret = !!(ret & sca3000_addresses[chan->address][2]);1149		}1150		break;1151	default:1152		ret = -EINVAL;1153	}1154 1155error_ret:1156	mutex_unlock(&st->lock);1157 1158	return ret;1159}1160 1161static int sca3000_freefall_set_state(struct iio_dev *indio_dev, int state)1162{1163	struct sca3000_state *st = iio_priv(indio_dev);1164	int ret;1165 1166	/* read current value of mode register */1167	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);1168	if (ret)1169		return ret;1170 1171	/* if off and should be on */1172	if (state && !(st->rx[0] & SCA3000_REG_MODE_FREE_FALL_DETECT))1173		return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR,1174					 st->rx[0] | SCA3000_REG_MODE_FREE_FALL_DETECT);1175	/* if on and should be off */1176	else if (!state && (st->rx[0] & SCA3000_REG_MODE_FREE_FALL_DETECT))1177		return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR,1178					 st->rx[0] & ~SCA3000_REG_MODE_FREE_FALL_DETECT);1179	else1180		return 0;1181}1182 1183static int sca3000_motion_detect_set_state(struct iio_dev *indio_dev, int axis,1184					   int state)1185{1186	struct sca3000_state *st = iio_priv(indio_dev);1187	int ret, ctrlval;1188 1189	/*1190	 * First read the motion detector config to find out if1191	 * this axis is on1192	 */1193	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);1194	if (ret < 0)1195		return ret;1196	ctrlval = ret;1197	/* if off and should be on */1198	if (state && !(ctrlval & sca3000_addresses[axis][2])) {1199		ret = sca3000_write_ctrl_reg(st,1200					     SCA3000_REG_CTRL_SEL_MD_CTRL,1201					     ctrlval |1202					     sca3000_addresses[axis][2]);1203		if (ret)1204			return ret;1205		st->mo_det_use_count++;1206	} else if (!state && (ctrlval & sca3000_addresses[axis][2])) {1207		ret = sca3000_write_ctrl_reg(st,1208					     SCA3000_REG_CTRL_SEL_MD_CTRL,1209					     ctrlval &1210					     ~(sca3000_addresses[axis][2]));1211		if (ret)1212			return ret;1213		st->mo_det_use_count--;1214	}1215 1216	/* read current value of mode register */1217	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);1218	if (ret)1219		return ret;1220	/* if off and should be on */1221	if ((st->mo_det_use_count) &&1222	    ((st->rx[0] & SCA3000_REG_MODE_MODE_MASK)1223	     != SCA3000_REG_MODE_MEAS_MODE_MOT_DET))1224		return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR,1225			(st->rx[0] & ~SCA3000_REG_MODE_MODE_MASK)1226			| SCA3000_REG_MODE_MEAS_MODE_MOT_DET);1227	/* if on and should be off */1228	else if (!(st->mo_det_use_count) &&1229		 ((st->rx[0] & SCA3000_REG_MODE_MODE_MASK)1230		  == SCA3000_REG_MODE_MEAS_MODE_MOT_DET))1231		return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR,1232			st->rx[0] & SCA3000_REG_MODE_MODE_MASK);1233	else1234		return 0;1235}1236 1237/**1238 * sca3000_write_event_config() - simple on off control for motion detector1239 * @indio_dev: IIO device instance specific structure. Data specific to this1240 * particular driver may be accessed via iio_priv(indio_dev).1241 * @chan: Description of the channel whose event we are configuring.1242 * @type: The type of event.1243 * @dir: The direction of the event.1244 * @state: Desired state of event being configured.1245 *1246 * This is a per axis control, but enabling any will result in the1247 * motion detector unit being enabled.1248 * N.B. enabling motion detector stops normal data acquisition.1249 * There is a complexity in knowing which mode to return to when1250 * this mode is disabled.  Currently normal mode is assumed.1251 **/1252static int sca3000_write_event_config(struct iio_dev *indio_dev,1253				      const struct iio_chan_spec *chan,1254				      enum iio_event_type type,1255				      enum iio_event_direction dir,1256				      int state)1257{1258	struct sca3000_state *st = iio_priv(indio_dev);1259	int ret;1260 1261	mutex_lock(&st->lock);1262	switch (chan->channel2) {1263	case IIO_MOD_X_AND_Y_AND_Z:1264		ret = sca3000_freefall_set_state(indio_dev, state);1265		break;1266 1267	case IIO_MOD_X:1268	case IIO_MOD_Y:1269	case IIO_MOD_Z:1270		ret = sca3000_motion_detect_set_state(indio_dev,1271						      chan->address,1272						      state);1273		break;1274	default:1275		ret = -EINVAL;1276		break;1277	}1278	mutex_unlock(&st->lock);1279 1280	return ret;1281}1282 1283static inline1284int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state)1285{1286	struct sca3000_state *st = iio_priv(indio_dev);1287	int ret;1288 1289	mutex_lock(&st->lock);1290	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);1291	if (ret)1292		goto error_ret;1293	if (state) {1294		dev_info(&indio_dev->dev, "supposedly enabling ring buffer\n");1295		ret = sca3000_write_reg(st,1296			SCA3000_REG_MODE_ADDR,1297			(st->rx[0] | SCA3000_REG_MODE_RING_BUF_ENABLE));1298	} else1299		ret = sca3000_write_reg(st,1300			SCA3000_REG_MODE_ADDR,1301			(st->rx[0] & ~SCA3000_REG_MODE_RING_BUF_ENABLE));1302error_ret:1303	mutex_unlock(&st->lock);1304 1305	return ret;1306}1307 1308/**1309 * sca3000_hw_ring_preenable() - hw ring buffer preenable function1310 * @indio_dev: structure representing the IIO device. Device instance1311 * specific state can be accessed via iio_priv(indio_dev).1312 *1313 * Very simple enable function as the chip will allows normal reads1314 * during ring buffer operation so as long as it is indeed running1315 * before we notify the core, the precise ordering does not matter.1316 */1317static int sca3000_hw_ring_preenable(struct iio_dev *indio_dev)1318{1319	int ret;1320	struct sca3000_state *st = iio_priv(indio_dev);1321 1322	mutex_lock(&st->lock);1323 1324	/* Enable the 50% full interrupt */1325	ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);1326	if (ret)1327		goto error_unlock;1328	ret = sca3000_write_reg(st,1329				SCA3000_REG_INT_MASK_ADDR,1330				st->rx[0] | SCA3000_REG_INT_MASK_RING_HALF);1331	if (ret)1332		goto error_unlock;1333 1334	mutex_unlock(&st->lock);1335 1336	return __sca3000_hw_ring_state_set(indio_dev, 1);1337 1338error_unlock:1339	mutex_unlock(&st->lock);1340 1341	return ret;1342}1343 1344static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev)1345{1346	int ret;1347	struct sca3000_state *st = iio_priv(indio_dev);1348 1349	ret = __sca3000_hw_ring_state_set(indio_dev, 0);1350	if (ret)1351		return ret;1352 1353	/* Disable the 50% full interrupt */1354	mutex_lock(&st->lock);1355 1356	ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);1357	if (ret)1358		goto unlock;1359	ret = sca3000_write_reg(st,1360				SCA3000_REG_INT_MASK_ADDR,1361				st->rx[0] & ~SCA3000_REG_INT_MASK_RING_HALF);1362unlock:1363	mutex_unlock(&st->lock);1364	return ret;1365}1366 1367static const struct iio_buffer_setup_ops sca3000_ring_setup_ops = {1368	.preenable = &sca3000_hw_ring_preenable,1369	.postdisable = &sca3000_hw_ring_postdisable,1370};1371 1372/**1373 * sca3000_clean_setup() - get the device into a predictable state1374 * @st: Device instance specific private data structure1375 *1376 * Devices use flash memory to store many of the register values1377 * and hence can come up in somewhat unpredictable states.1378 * Hence reset everything on driver load.1379 */1380static int sca3000_clean_setup(struct sca3000_state *st)1381{1382	int ret;1383 1384	mutex_lock(&st->lock);1385	/* Ensure all interrupts have been acknowledged */1386	ret = sca3000_read_data_short(st, SCA3000_REG_INT_STATUS_ADDR, 1);1387	if (ret)1388		goto error_ret;1389 1390	/* Turn off all motion detection channels */1391	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);1392	if (ret < 0)1393		goto error_ret;1394	ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL,1395				     ret & SCA3000_MD_CTRL_PROT_MASK);1396	if (ret)1397		goto error_ret;1398 1399	/* Disable ring buffer */1400	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);1401	if (ret < 0)1402		goto error_ret;1403	ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL,1404				     (ret & SCA3000_REG_OUT_CTRL_PROT_MASK)1405				     | SCA3000_REG_OUT_CTRL_BUF_X_EN1406				     | SCA3000_REG_OUT_CTRL_BUF_Y_EN1407				     | SCA3000_REG_OUT_CTRL_BUF_Z_EN1408				     | SCA3000_REG_OUT_CTRL_BUF_DIV_4);1409	if (ret)1410		goto error_ret;1411	/* Enable interrupts, relevant to mode and set up as active low */1412	ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);1413	if (ret)1414		goto error_ret;1415	ret = sca3000_write_reg(st,1416				SCA3000_REG_INT_MASK_ADDR,1417				(ret & SCA3000_REG_INT_MASK_PROT_MASK)1418				| SCA3000_REG_INT_MASK_ACTIVE_LOW);1419	if (ret)1420		goto error_ret;1421	/*1422	 * Select normal measurement mode, free fall off, ring off1423	 * Ring in 12 bit mode - it is fine to overwrite reserved bits 3,51424	 * as that occurs in one of the example on the datasheet1425	 */1426	ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);1427	if (ret)1428		goto error_ret;1429	ret = sca3000_write_reg(st, SCA3000_REG_MODE_ADDR,1430				(st->rx[0] & SCA3000_MODE_PROT_MASK));1431 1432error_ret:1433	mutex_unlock(&st->lock);1434	return ret;1435}1436 1437static const struct iio_info sca3000_info = {1438	.attrs = &sca3000_attribute_group,1439	.read_raw = &sca3000_read_raw,1440	.write_raw = &sca3000_write_raw,1441	.read_event_value = &sca3000_read_event_value,1442	.write_event_value = &sca3000_write_event_value,1443	.read_event_config = &sca3000_read_event_config,1444	.write_event_config = &sca3000_write_event_config,1445};1446 1447static int sca3000_probe(struct spi_device *spi)1448{1449	int ret;1450	struct sca3000_state *st;1451	struct iio_dev *indio_dev;1452 1453	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));1454	if (!indio_dev)1455		return -ENOMEM;1456 1457	st = iio_priv(indio_dev);1458	spi_set_drvdata(spi, indio_dev);1459	st->us = spi;1460	mutex_init(&st->lock);1461	st->info = &sca3000_spi_chip_info_tbl[spi_get_device_id(spi)1462					      ->driver_data];1463 1464	indio_dev->name = spi_get_device_id(spi)->name;1465	indio_dev->info = &sca3000_info;1466	if (st->info->temp_output) {1467		indio_dev->channels = sca3000_channels_with_temp;1468		indio_dev->num_channels =1469			ARRAY_SIZE(sca3000_channels_with_temp);1470	} else {1471		indio_dev->channels = sca3000_channels;1472		indio_dev->num_channels = ARRAY_SIZE(sca3000_channels);1473	}1474	indio_dev->modes = INDIO_DIRECT_MODE;1475 1476	ret = devm_iio_kfifo_buffer_setup(&spi->dev, indio_dev,1477					  &sca3000_ring_setup_ops);1478	if (ret)1479		return ret;1480 1481	if (spi->irq) {1482		ret = request_threaded_irq(spi->irq,1483					   NULL,1484					   &sca3000_event_handler,1485					   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,1486					   "sca3000",1487					   indio_dev);1488		if (ret)1489			return ret;1490	}1491	ret = sca3000_clean_setup(st);1492	if (ret)1493		goto error_free_irq;1494 1495	ret = sca3000_print_rev(indio_dev);1496	if (ret)1497		goto error_free_irq;1498 1499	return iio_device_register(indio_dev);1500 1501error_free_irq:1502	if (spi->irq)1503		free_irq(spi->irq, indio_dev);1504 1505	return ret;1506}1507 1508static int sca3000_stop_all_interrupts(struct sca3000_state *st)1509{1510	int ret;1511 1512	mutex_lock(&st->lock);1513	ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);1514	if (ret)1515		goto error_ret;1516	ret = sca3000_write_reg(st, SCA3000_REG_INT_MASK_ADDR,1517				(st->rx[0] &1518				 ~(SCA3000_REG_INT_MASK_RING_THREE_QUARTER |1519				   SCA3000_REG_INT_MASK_RING_HALF |1520				   SCA3000_REG_INT_MASK_ALL_INTS)));1521error_ret:1522	mutex_unlock(&st->lock);1523	return ret;1524}1525 1526static void sca3000_remove(struct spi_device *spi)1527{1528	struct iio_dev *indio_dev = spi_get_drvdata(spi);1529	struct sca3000_state *st = iio_priv(indio_dev);1530 1531	iio_device_unregister(indio_dev);1532 1533	/* Must ensure no interrupts can be generated after this! */1534	sca3000_stop_all_interrupts(st);1535	if (spi->irq)1536		free_irq(spi->irq, indio_dev);1537}1538 1539static const struct spi_device_id sca3000_id[] = {1540	{"sca3000_d01", d01},1541	{"sca3000_e02", e02},1542	{"sca3000_e04", e04},1543	{"sca3000_e05", e05},1544	{}1545};1546MODULE_DEVICE_TABLE(spi, sca3000_id);1547 1548static struct spi_driver sca3000_driver = {1549	.driver = {1550		.name = "sca3000",1551	},1552	.probe = sca3000_probe,1553	.remove = sca3000_remove,1554	.id_table = sca3000_id,1555};1556module_spi_driver(sca3000_driver);1557 1558MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");1559MODULE_DESCRIPTION("VTI SCA3000 Series Accelerometers SPI driver");1560MODULE_LICENSE("GPL v2");1561