Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1081 insertions, 0 deletions

diff --git a/drivers/iio/proximity/sx9500.c b/drivers/iio/proximity/sx9500.c
new file mode 100644
index 000000000..ff80409e0
--- /dev/null
+++ b/drivers/iio/proximity/sx9500.c
@@ -0,0 +1,1081 @@
+/*
+ * Copyright (c) 2014 Intel Corporation
+ *
+ * Driver for Semtech's SX9500 capacitive proximity/button solution.
+ * Datasheet available at
+ * <http://www.semtech.com/images/datasheet/sx9500.pdf>.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regmap.h>
+#include <linux/pm.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#define SX9500_DRIVER_NAME		"sx9500"
+#define SX9500_IRQ_NAME			"sx9500_event"
+
+/* Register definitions. */
+#define SX9500_REG_IRQ_SRC		0x00
+#define SX9500_REG_STAT			0x01
+#define SX9500_REG_IRQ_MSK		0x03
+
+#define SX9500_REG_PROX_CTRL0		0x06
+#define SX9500_REG_PROX_CTRL1		0x07
+#define SX9500_REG_PROX_CTRL2		0x08
+#define SX9500_REG_PROX_CTRL3		0x09
+#define SX9500_REG_PROX_CTRL4		0x0a
+#define SX9500_REG_PROX_CTRL5		0x0b
+#define SX9500_REG_PROX_CTRL6		0x0c
+#define SX9500_REG_PROX_CTRL7		0x0d
+#define SX9500_REG_PROX_CTRL8		0x0e
+
+#define SX9500_REG_SENSOR_SEL		0x20
+#define SX9500_REG_USE_MSB		0x21
+#define SX9500_REG_USE_LSB		0x22
+#define SX9500_REG_AVG_MSB		0x23
+#define SX9500_REG_AVG_LSB		0x24
+#define SX9500_REG_DIFF_MSB		0x25
+#define SX9500_REG_DIFF_LSB		0x26
+#define SX9500_REG_OFFSET_MSB		0x27
+#define SX9500_REG_OFFSET_LSB		0x28
+
+#define SX9500_REG_RESET		0x7f
+
+/* Write this to REG_RESET to do a soft reset. */
+#define SX9500_SOFT_RESET		0xde
+
+#define SX9500_SCAN_PERIOD_MASK		GENMASK(6, 4)
+#define SX9500_SCAN_PERIOD_SHIFT	4
+
+/*
+ * These serve for identifying IRQ source in the IRQ_SRC register, and
+ * also for masking the IRQs in the IRQ_MSK register.
+ */
+#define SX9500_CLOSE_IRQ		BIT(6)
+#define SX9500_FAR_IRQ			BIT(5)
+#define SX9500_CONVDONE_IRQ		BIT(3)
+
+#define SX9500_PROXSTAT_SHIFT		4
+#define SX9500_COMPSTAT_MASK		GENMASK(3, 0)
+
+#define SX9500_NUM_CHANNELS		4
+#define SX9500_CHAN_MASK		GENMASK(SX9500_NUM_CHANNELS - 1, 0)
+
+struct sx9500_data {
+	struct mutex mutex;
+	struct i2c_client *client;
+	struct iio_trigger *trig;
+	struct regmap *regmap;
+	struct gpio_desc *gpiod_rst;
+	/*
+	 * Last reading of the proximity status for each channel.  We
+	 * only send an event to user space when this changes.
+	 */
+	bool prox_stat[SX9500_NUM_CHANNELS];
+	bool event_enabled[SX9500_NUM_CHANNELS];
+	bool trigger_enabled;
+	u16 *buffer;
+	/* Remember enabled channels and sample rate during suspend. */
+	unsigned int suspend_ctrl0;
+	struct completion completion;
+	int data_rdy_users, close_far_users;
+	int channel_users[SX9500_NUM_CHANNELS];
+};
+
+static const struct iio_event_spec sx9500_events[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
+#define SX9500_CHANNEL(idx)					\
+	{							\
+		.type = IIO_PROXIMITY,				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+		.indexed = 1,					\
+		.channel = idx,					\
+		.event_spec = sx9500_events,			\
+		.num_event_specs = ARRAY_SIZE(sx9500_events),	\
+		.scan_index = idx,				\
+		.scan_type = {					\
+			.sign = 'u',				\
+			.realbits = 16,				\
+			.storagebits = 16,			\
+			.shift = 0,				\
+		},						\
+	}
+
+static const struct iio_chan_spec sx9500_channels[] = {
+	SX9500_CHANNEL(0),
+	SX9500_CHANNEL(1),
+	SX9500_CHANNEL(2),
+	SX9500_CHANNEL(3),
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static const struct {
+	int val;
+	int val2;
+} sx9500_samp_freq_table[] = {
+	{33, 333333},
+	{16, 666666},
+	{11, 111111},
+	{8, 333333},
+	{6, 666666},
+	{5, 0},
+	{3, 333333},
+	{2, 500000},
+};
+
+static const unsigned int sx9500_scan_period_table[] = {
+	30, 60, 90, 120, 150, 200, 300, 400,
+};
+
+static const struct regmap_range sx9500_writable_reg_ranges[] = {
+	regmap_reg_range(SX9500_REG_IRQ_MSK, SX9500_REG_IRQ_MSK),
+	regmap_reg_range(SX9500_REG_PROX_CTRL0, SX9500_REG_PROX_CTRL8),
+	regmap_reg_range(SX9500_REG_SENSOR_SEL, SX9500_REG_SENSOR_SEL),
+	regmap_reg_range(SX9500_REG_OFFSET_MSB, SX9500_REG_OFFSET_LSB),
+	regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
+};
+
+static const struct regmap_access_table sx9500_writeable_regs = {
+	.yes_ranges = sx9500_writable_reg_ranges,
+	.n_yes_ranges = ARRAY_SIZE(sx9500_writable_reg_ranges),
+};
+
+/*
+ * All allocated registers are readable, so we just list unallocated
+ * ones.
+ */
+static const struct regmap_range sx9500_non_readable_reg_ranges[] = {
+	regmap_reg_range(SX9500_REG_STAT + 1, SX9500_REG_STAT + 1),
+	regmap_reg_range(SX9500_REG_IRQ_MSK + 1, SX9500_REG_PROX_CTRL0 - 1),
+	regmap_reg_range(SX9500_REG_PROX_CTRL8 + 1, SX9500_REG_SENSOR_SEL - 1),
+	regmap_reg_range(SX9500_REG_OFFSET_LSB + 1, SX9500_REG_RESET - 1),
+};
+
+static const struct regmap_access_table sx9500_readable_regs = {
+	.no_ranges = sx9500_non_readable_reg_ranges,
+	.n_no_ranges = ARRAY_SIZE(sx9500_non_readable_reg_ranges),
+};
+
+static const struct regmap_range sx9500_volatile_reg_ranges[] = {
+	regmap_reg_range(SX9500_REG_IRQ_SRC, SX9500_REG_STAT),
+	regmap_reg_range(SX9500_REG_USE_MSB, SX9500_REG_OFFSET_LSB),
+	regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
+};
+
+static const struct regmap_access_table sx9500_volatile_regs = {
+	.yes_ranges = sx9500_volatile_reg_ranges,
+	.n_yes_ranges = ARRAY_SIZE(sx9500_volatile_reg_ranges),
+};
+
+static const struct regmap_config sx9500_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = SX9500_REG_RESET,
+	.cache_type = REGCACHE_RBTREE,
+
+	.wr_table = &sx9500_writeable_regs,
+	.rd_table = &sx9500_readable_regs,
+	.volatile_table = &sx9500_volatile_regs,
+};
+
+static int sx9500_inc_users(struct sx9500_data *data, int *counter,
+			    unsigned int reg, unsigned int bitmask)
+{
+	(*counter)++;
+	if (*counter != 1)
+		/* Bit is already active, nothing to do. */
+		return 0;
+
+	return regmap_update_bits(data->regmap, reg, bitmask, bitmask);
+}
+
+static int sx9500_dec_users(struct sx9500_data *data, int *counter,
+			    unsigned int reg, unsigned int bitmask)
+{
+	(*counter)--;
+	if (*counter != 0)
+		/* There are more users, do not deactivate. */
+		return 0;
+
+	return regmap_update_bits(data->regmap, reg, bitmask, 0);
+}
+
+static int sx9500_inc_chan_users(struct sx9500_data *data, int chan)
+{
+	return sx9500_inc_users(data, &data->channel_users[chan],
+				SX9500_REG_PROX_CTRL0, BIT(chan));
+}
+
+static int sx9500_dec_chan_users(struct sx9500_data *data, int chan)
+{
+	return sx9500_dec_users(data, &data->channel_users[chan],
+				SX9500_REG_PROX_CTRL0, BIT(chan));
+}
+
+static int sx9500_inc_data_rdy_users(struct sx9500_data *data)
+{
+	return sx9500_inc_users(data, &data->data_rdy_users,
+				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
+}
+
+static int sx9500_dec_data_rdy_users(struct sx9500_data *data)
+{
+	return sx9500_dec_users(data, &data->data_rdy_users,
+				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
+}
+
+static int sx9500_inc_close_far_users(struct sx9500_data *data)
+{
+	return sx9500_inc_users(data, &data->close_far_users,
+				SX9500_REG_IRQ_MSK,
+				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
+}
+
+static int sx9500_dec_close_far_users(struct sx9500_data *data)
+{
+	return sx9500_dec_users(data, &data->close_far_users,
+				SX9500_REG_IRQ_MSK,
+				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
+}
+
+static int sx9500_read_prox_data(struct sx9500_data *data,
+				 const struct iio_chan_spec *chan,
+				 int *val)
+{
+	int ret;
+	__be16 regval;
+
+	ret = regmap_write(data->regmap, SX9500_REG_SENSOR_SEL, chan->channel);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, SX9500_REG_USE_MSB, &regval, 2);
+	if (ret < 0)
+		return ret;
+
+	*val = be16_to_cpu(regval);
+
+	return IIO_VAL_INT;
+}
+
+/*
+ * If we have no interrupt support, we have to wait for a scan period
+ * after enabling a channel to get a result.
+ */
+static int sx9500_wait_for_sample(struct sx9500_data *data)
+{
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &val);
+	if (ret < 0)
+		return ret;
+
+	val = (val & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
+
+	msleep(sx9500_scan_period_table[val]);
+
+	return 0;
+}
+
+static int sx9500_read_proximity(struct sx9500_data *data,
+				 const struct iio_chan_spec *chan,
+				 int *val)
+{
+	int ret;
+
+	mutex_lock(&data->mutex);
+
+	ret = sx9500_inc_chan_users(data, chan->channel);
+	if (ret < 0)
+		goto out;
+
+	ret = sx9500_inc_data_rdy_users(data);
+	if (ret < 0)
+		goto out_dec_chan;
+
+	mutex_unlock(&data->mutex);
+
+	if (data->client->irq > 0)
+		ret = wait_for_completion_interruptible(&data->completion);
+	else
+		ret = sx9500_wait_for_sample(data);
+
+	mutex_lock(&data->mutex);
+
+	if (ret < 0)
+		goto out_dec_data_rdy;
+
+	ret = sx9500_read_prox_data(data, chan, val);
+	if (ret < 0)
+		goto out_dec_data_rdy;
+
+	ret = sx9500_dec_data_rdy_users(data);
+	if (ret < 0)
+		goto out_dec_chan;
+
+	ret = sx9500_dec_chan_users(data, chan->channel);
+	if (ret < 0)
+		goto out;
+
+	ret = IIO_VAL_INT;
+
+	goto out;
+
+out_dec_data_rdy:
+	sx9500_dec_data_rdy_users(data);
+out_dec_chan:
+	sx9500_dec_chan_users(data, chan->channel);
+out:
+	mutex_unlock(&data->mutex);
+	reinit_completion(&data->completion);
+
+	return ret;
+}
+
+static int sx9500_read_samp_freq(struct sx9500_data *data,
+				 int *val, int *val2)
+{
+	int ret;
+	unsigned int regval;
+
+	mutex_lock(&data->mutex);
+	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &regval);
+	mutex_unlock(&data->mutex);
+
+	if (ret < 0)
+		return ret;
+
+	regval = (regval & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
+	*val = sx9500_samp_freq_table[regval].val;
+	*val2 = sx9500_samp_freq_table[regval].val2;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int sx9500_read_raw(struct iio_dev *indio_dev,
+			   const struct iio_chan_spec *chan,
+			   int *val, int *val2, long mask)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (chan->type) {
+	case IIO_PROXIMITY:
+		switch (mask) {
+		case IIO_CHAN_INFO_RAW:
+			ret = iio_device_claim_direct_mode(indio_dev);
+			if (ret)
+				return ret;
+			ret = sx9500_read_proximity(data, chan, val);
+			iio_device_release_direct_mode(indio_dev);
+			return ret;
+		case IIO_CHAN_INFO_SAMP_FREQ:
+			return sx9500_read_samp_freq(data, val, val2);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int sx9500_set_samp_freq(struct sx9500_data *data,
+				int val, int val2)
+{
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(sx9500_samp_freq_table); i++)
+		if (val == sx9500_samp_freq_table[i].val &&
+		    val2 == sx9500_samp_freq_table[i].val2)
+			break;
+
+	if (i == ARRAY_SIZE(sx9500_samp_freq_table))
+		return -EINVAL;
+
+	mutex_lock(&data->mutex);
+
+	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
+				 SX9500_SCAN_PERIOD_MASK,
+				 i << SX9500_SCAN_PERIOD_SHIFT);
+
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9500_write_raw(struct iio_dev *indio_dev,
+			    const struct iio_chan_spec *chan,
+			    int val, int val2, long mask)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+
+	switch (chan->type) {
+	case IIO_PROXIMITY:
+		switch (mask) {
+		case IIO_CHAN_INFO_SAMP_FREQ:
+			return sx9500_set_samp_freq(data, val, val2);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static irqreturn_t sx9500_irq_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct sx9500_data *data = iio_priv(indio_dev);
+
+	if (data->trigger_enabled)
+		iio_trigger_poll(data->trig);
+
+	/*
+	 * Even if no event is enabled, we need to wake the thread to
+	 * clear the interrupt state by reading SX9500_REG_IRQ_SRC.  It
+	 * is not possible to do that here because regmap_read takes a
+	 * mutex.
+	 */
+	return IRQ_WAKE_THREAD;
+}
+
+static void sx9500_push_events(struct iio_dev *indio_dev)
+{
+	int ret;
+	unsigned int val, chan;
+	struct sx9500_data *data = iio_priv(indio_dev);
+
+	ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "i2c transfer error in irq\n");
+		return;
+	}
+
+	val >>= SX9500_PROXSTAT_SHIFT;
+	for (chan = 0; chan < SX9500_NUM_CHANNELS; chan++) {
+		int dir;
+		u64 ev;
+		bool new_prox = val & BIT(chan);
+
+		if (!data->event_enabled[chan])
+			continue;
+		if (new_prox == data->prox_stat[chan])
+			/* No change on this channel. */
+			continue;
+
+		dir = new_prox ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
+		ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
+					  IIO_EV_TYPE_THRESH, dir);
+		iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));
+		data->prox_stat[chan] = new_prox;
+	}
+}
+
+static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret;
+	unsigned int val;
+
+	mutex_lock(&data->mutex);
+
+	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "i2c transfer error in irq\n");
+		goto out;
+	}
+
+	if (val & (SX9500_CLOSE_IRQ | SX9500_FAR_IRQ))
+		sx9500_push_events(indio_dev);
+
+	if (val & SX9500_CONVDONE_IRQ)
+		complete(&data->completion);
+
+out:
+	mutex_unlock(&data->mutex);
+
+	return IRQ_HANDLED;
+}
+
+static int sx9500_read_event_config(struct iio_dev *indio_dev,
+				    const struct iio_chan_spec *chan,
+				    enum iio_event_type type,
+				    enum iio_event_direction dir)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+
+	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
+	    dir != IIO_EV_DIR_EITHER)
+		return -EINVAL;
+
+	return data->event_enabled[chan->channel];
+}
+
+static int sx9500_write_event_config(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan,
+				     enum iio_event_type type,
+				     enum iio_event_direction dir,
+				     int state)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
+	    dir != IIO_EV_DIR_EITHER)
+		return -EINVAL;
+
+	mutex_lock(&data->mutex);
+
+	if (state == 1) {
+		ret = sx9500_inc_chan_users(data, chan->channel);
+		if (ret < 0)
+			goto out_unlock;
+		ret = sx9500_inc_close_far_users(data);
+		if (ret < 0)
+			goto out_undo_chan;
+	} else {
+		ret = sx9500_dec_chan_users(data, chan->channel);
+		if (ret < 0)
+			goto out_unlock;
+		ret = sx9500_dec_close_far_users(data);
+		if (ret < 0)
+			goto out_undo_chan;
+	}
+
+	data->event_enabled[chan->channel] = state;
+	goto out_unlock;
+
+out_undo_chan:
+	if (state == 1)
+		sx9500_dec_chan_users(data, chan->channel);
+	else
+		sx9500_inc_chan_users(data, chan->channel);
+out_unlock:
+	mutex_unlock(&data->mutex);
+	return ret;
+}
+
+static int sx9500_update_scan_mode(struct iio_dev *indio_dev,
+				   const unsigned long *scan_mask)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+
+	mutex_lock(&data->mutex);
+	kfree(data->buffer);
+	data->buffer = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
+	mutex_unlock(&data->mutex);
+
+	if (data->buffer == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
+	"2.500000 3.333333 5 6.666666 8.333333 11.111111 16.666666 33.333333");
+
+static struct attribute *sx9500_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group sx9500_attribute_group = {
+	.attrs = sx9500_attributes,
+};
+
+static const struct iio_info sx9500_info = {
+	.attrs = &sx9500_attribute_group,
+	.read_raw = &sx9500_read_raw,
+	.write_raw = &sx9500_write_raw,
+	.read_event_config = &sx9500_read_event_config,
+	.write_event_config = &sx9500_write_event_config,
+	.update_scan_mode = &sx9500_update_scan_mode,
+};
+
+static int sx9500_set_trigger_state(struct iio_trigger *trig,
+				    bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+
+	if (state)
+		ret = sx9500_inc_data_rdy_users(data);
+	else
+		ret = sx9500_dec_data_rdy_users(data);
+	if (ret < 0)
+		goto out;
+
+	data->trigger_enabled = state;
+
+out:
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static const struct iio_trigger_ops sx9500_trigger_ops = {
+	.set_trigger_state = sx9500_set_trigger_state,
+};
+
+static irqreturn_t sx9500_trigger_handler(int irq, void *private)
+{
+	struct iio_poll_func *pf = private;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int val, bit, ret, i = 0;
+
+	mutex_lock(&data->mutex);
+
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
+			 indio_dev->masklength) {
+		ret = sx9500_read_prox_data(data, &indio_dev->channels[bit],
+					    &val);
+		if (ret < 0)
+			goto out;
+
+		data->buffer[i++] = val;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   iio_get_time_ns(indio_dev));
+
+out:
+	mutex_unlock(&data->mutex);
+
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int sx9500_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret = 0, i;
+
+	mutex_lock(&data->mutex);
+
+	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
+		if (test_bit(i, indio_dev->active_scan_mask)) {
+			ret = sx9500_inc_chan_users(data, i);
+			if (ret)
+				break;
+		}
+
+	if (ret)
+		for (i = i - 1; i >= 0; i--)
+			if (test_bit(i, indio_dev->active_scan_mask))
+				sx9500_dec_chan_users(data, i);
+
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int sx9500_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret = 0, i;
+
+	iio_triggered_buffer_predisable(indio_dev);
+
+	mutex_lock(&data->mutex);
+
+	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
+		if (test_bit(i, indio_dev->active_scan_mask)) {
+			ret = sx9500_dec_chan_users(data, i);
+			if (ret)
+				break;
+		}
+
+	if (ret)
+		for (i = i - 1; i >= 0; i--)
+			if (test_bit(i, indio_dev->active_scan_mask))
+				sx9500_inc_chan_users(data, i);
+
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static const struct iio_buffer_setup_ops sx9500_buffer_setup_ops = {
+	.preenable = sx9500_buffer_preenable,
+	.postenable = iio_triggered_buffer_postenable,
+	.predisable = sx9500_buffer_predisable,
+};
+
+struct sx9500_reg_default {
+	u8 reg;
+	u8 def;
+};
+
+static const struct sx9500_reg_default sx9500_default_regs[] = {
+	{
+		.reg = SX9500_REG_PROX_CTRL1,
+		/* Shield enabled, small range. */
+		.def = 0x43,
+	},
+	{
+		.reg = SX9500_REG_PROX_CTRL2,
+		/* x8 gain, 167kHz frequency, finest resolution. */
+		.def = 0x77,
+	},
+	{
+		.reg = SX9500_REG_PROX_CTRL3,
+		/* Doze enabled, 2x scan period doze, no raw filter. */
+		.def = 0x40,
+	},
+	{
+		.reg = SX9500_REG_PROX_CTRL4,
+		/* Average threshold. */
+		.def = 0x30,
+	},
+	{
+		.reg = SX9500_REG_PROX_CTRL5,
+		/*
+		 * Debouncer off, lowest average negative filter,
+		 * highest average postive filter.
+		 */
+		.def = 0x0f,
+	},
+	{
+		.reg = SX9500_REG_PROX_CTRL6,
+		/* Proximity detection threshold: 280 */
+		.def = 0x0e,
+	},
+	{
+		.reg = SX9500_REG_PROX_CTRL7,
+		/*
+		 * No automatic compensation, compensate each pin
+		 * independently, proximity hysteresis: 32, close
+		 * debouncer off, far debouncer off.
+		 */
+		.def = 0x00,
+	},
+	{
+		.reg = SX9500_REG_PROX_CTRL8,
+		/* No stuck timeout, no periodic compensation. */
+		.def = 0x00,
+	},
+	{
+		.reg = SX9500_REG_PROX_CTRL0,
+		/* Scan period: 30ms, all sensors disabled. */
+		.def = 0x00,
+	},
+};
+
+/* Activate all channels and perform an initial compensation. */
+static int sx9500_init_compensation(struct iio_dev *indio_dev)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int i, ret;
+	unsigned int val;
+
+	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
+				 SX9500_CHAN_MASK, SX9500_CHAN_MASK);
+	if (ret < 0)
+		return ret;
+
+	for (i = 10; i >= 0; i--) {
+		usleep_range(10000, 20000);
+		ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
+		if (ret < 0)
+			goto out;
+		if (!(val & SX9500_COMPSTAT_MASK))
+			break;
+	}
+
+	if (i < 0) {
+		dev_err(&data->client->dev, "initial compensation timed out");
+		ret = -ETIMEDOUT;
+	}
+
+out:
+	regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
+			   SX9500_CHAN_MASK, 0);
+	return ret;
+}
+
+static int sx9500_init_device(struct iio_dev *indio_dev)
+{
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret, i;
+	unsigned int val;
+
+	if (data->gpiod_rst) {
+		gpiod_set_value_cansleep(data->gpiod_rst, 0);
+		usleep_range(1000, 2000);
+		gpiod_set_value_cansleep(data->gpiod_rst, 1);
+		usleep_range(1000, 2000);
+	}
+
+	ret = regmap_write(data->regmap, SX9500_REG_IRQ_MSK, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(data->regmap, SX9500_REG_RESET,
+			   SX9500_SOFT_RESET);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(sx9500_default_regs); i++) {
+		ret = regmap_write(data->regmap,
+				   sx9500_default_regs[i].reg,
+				   sx9500_default_regs[i].def);
+		if (ret < 0)
+			return ret;
+	}
+
+	return sx9500_init_compensation(indio_dev);
+}
+
+static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
+static const struct acpi_gpio_params interrupt_gpios = { 2, 0, false };
+
+static const struct acpi_gpio_mapping acpi_sx9500_gpios[] = {
+	{ "reset-gpios", &reset_gpios, 1 },
+	/*
+	 * Some platforms have a bug in ACPI GPIO description making IRQ
+	 * GPIO to be output only. Ask the GPIO core to ignore this limit.
+	 */
+	{ "interrupt-gpios", &interrupt_gpios, 1, ACPI_GPIO_QUIRK_NO_IO_RESTRICTION },
+	{ },
+};
+
+static void sx9500_gpio_probe(struct i2c_client *client,
+			      struct sx9500_data *data)
+{
+	struct gpio_desc *gpiod_int;
+	struct device *dev;
+	int ret;
+
+	if (!client)
+		return;
+
+	dev = &client->dev;
+
+	ret = devm_acpi_dev_add_driver_gpios(dev, acpi_sx9500_gpios);
+	if (ret)
+		dev_dbg(dev, "Unable to add GPIO mapping table\n");
+
+	if (client->irq <= 0) {
+		gpiod_int = devm_gpiod_get(dev, "interrupt", GPIOD_IN);
+		if (IS_ERR(gpiod_int))
+			dev_err(dev, "gpio get irq failed\n");
+		else
+			client->irq = gpiod_to_irq(gpiod_int);
+	}
+
+	data->gpiod_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(data->gpiod_rst)) {
+		dev_warn(dev, "gpio get reset pin failed\n");
+		data->gpiod_rst = NULL;
+	}
+}
+
+static int sx9500_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	int ret;
+	struct iio_dev *indio_dev;
+	struct sx9500_data *data;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	mutex_init(&data->mutex);
+	init_completion(&data->completion);
+	data->trigger_enabled = false;
+
+	data->regmap = devm_regmap_init_i2c(client, &sx9500_regmap_config);
+	if (IS_ERR(data->regmap))
+		return PTR_ERR(data->regmap);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = SX9500_DRIVER_NAME;
+	indio_dev->channels = sx9500_channels;
+	indio_dev->num_channels = ARRAY_SIZE(sx9500_channels);
+	indio_dev->info = &sx9500_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	i2c_set_clientdata(client, indio_dev);
+
+	sx9500_gpio_probe(client, data);
+
+	ret = sx9500_init_device(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	if (client->irq <= 0)
+		dev_warn(&client->dev, "no valid irq found\n");
+	else {
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+				sx9500_irq_handler, sx9500_irq_thread_handler,
+				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				SX9500_IRQ_NAME, indio_dev);
+		if (ret < 0)
+			return ret;
+
+		data->trig = devm_iio_trigger_alloc(&client->dev,
+				"%s-dev%d", indio_dev->name, indio_dev->id);
+		if (!data->trig)
+			return -ENOMEM;
+
+		data->trig->dev.parent = &client->dev;
+		data->trig->ops = &sx9500_trigger_ops;
+		iio_trigger_set_drvdata(data->trig, indio_dev);
+
+		ret = iio_trigger_register(data->trig);
+		if (ret)
+			return ret;
+	}
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+					 sx9500_trigger_handler,
+					 &sx9500_buffer_setup_ops);
+	if (ret < 0)
+		goto out_trigger_unregister;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto out_buffer_cleanup;
+
+	return 0;
+
+out_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+out_trigger_unregister:
+	if (client->irq > 0)
+		iio_trigger_unregister(data->trig);
+
+	return ret;
+}
+
+static int sx9500_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct sx9500_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	if (client->irq > 0)
+		iio_trigger_unregister(data->trig);
+	kfree(data->buffer);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int sx9500_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0,
+			  &data->suspend_ctrl0);
+	if (ret < 0)
+		goto out;
+
+	/*
+	 * Scan period doesn't matter because when all the sensors are
+	 * deactivated the device is in sleep mode.
+	 */
+	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0, 0);
+
+out:
+	mutex_unlock(&data->mutex);
+	return ret;
+}
+
+static int sx9500_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0,
+			   data->suspend_ctrl0);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops sx9500_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(sx9500_suspend, sx9500_resume)
+};
+
+static const struct acpi_device_id sx9500_acpi_match[] = {
+	{"SSX9500", 0},
+	{"SASX9500", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, sx9500_acpi_match);
+
+static const struct of_device_id sx9500_of_match[] = {
+	{ .compatible = "semtech,sx9500", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sx9500_of_match);
+
+static const struct i2c_device_id sx9500_id[] = {
+	{"sx9500", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, sx9500_id);
+
+static struct i2c_driver sx9500_driver = {
+	.driver = {
+		.name	= SX9500_DRIVER_NAME,
+		.acpi_match_table = ACPI_PTR(sx9500_acpi_match),
+		.of_match_table = of_match_ptr(sx9500_of_match),
+		.pm = &sx9500_pm_ops,
+	},
+	.probe		= sx9500_probe,
+	.remove		= sx9500_remove,
+	.id_table	= sx9500_id,
+};
+module_i2c_driver(sx9500_driver);
+
+MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
+MODULE_DESCRIPTION("Driver for Semtech SX9500 proximity sensor");
+MODULE_LICENSE("GPL v2");