1 files changed, 569 insertions, 0 deletions

diff --git a/drivers/iio/proximity/sx_common.c b/drivers/iio/proximity/sx_common.c
new file mode 100644
index 000000000..d70a6b4f0
--- /dev/null
+++ b/drivers/iio/proximity/sx_common.c
@@ -0,0 +1,569 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2021 Google LLC.
+ *
+ * Common part of most Semtech SAR sensor.
+ */
+
+#include <linux/bitops.h>
+#include <linux/byteorder/generic.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <vdso/bits.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include "sx_common.h"
+
+/* All Semtech SAR sensors have IRQ bit in the same order. */
+#define   SX_COMMON_CONVDONE_IRQ			BIT(0)
+#define   SX_COMMON_FAR_IRQ				BIT(2)
+#define   SX_COMMON_CLOSE_IRQ				BIT(3)
+
+const struct iio_event_spec sx_common_events[3] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_shared_by_all = BIT(IIO_EV_INFO_PERIOD),
+	},
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_shared_by_all = BIT(IIO_EV_INFO_PERIOD),
+	},
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+				 BIT(IIO_EV_INFO_HYSTERESIS) |
+				 BIT(IIO_EV_INFO_VALUE),
+	},
+};
+EXPORT_SYMBOL_NS_GPL(sx_common_events, SEMTECH_PROX);
+
+static irqreturn_t sx_common_irq_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct sx_common_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 SX_COMMON_REG_IRQ_SRC.
+	 * It is not possible to do that here because regmap_read takes a mutex.
+	 */
+	return IRQ_WAKE_THREAD;
+}
+
+static void sx_common_push_events(struct iio_dev *indio_dev)
+{
+	int ret;
+	unsigned int val, chan;
+	struct sx_common_data *data = iio_priv(indio_dev);
+	s64 timestamp = iio_get_time_ns(indio_dev);
+	unsigned long prox_changed;
+
+	/* Read proximity state on all channels */
+	ret = regmap_read(data->regmap, data->chip_info->reg_stat, &val);
+	if (ret) {
+		dev_err(&data->client->dev, "i2c transfer error in irq\n");
+		return;
+	}
+
+	val >>= data->chip_info->stat_offset;
+
+	/*
+	 * Only iterate over channels with changes on proximity status that have
+	 * events enabled.
+	 */
+	prox_changed = (data->chan_prox_stat ^ val) & data->chan_event;
+
+	for_each_set_bit(chan, &prox_changed, data->chip_info->num_channels) {
+		int dir;
+		u64 ev;
+
+		dir = (val & BIT(chan)) ? 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, timestamp);
+	}
+	data->chan_prox_stat = val;
+}
+
+static int sx_common_enable_irq(struct sx_common_data *data, unsigned int irq)
+{
+	if (!data->client->irq)
+		return 0;
+	return regmap_update_bits(data->regmap, data->chip_info->reg_irq_msk,
+				  irq << data->chip_info->irq_msk_offset,
+				  irq << data->chip_info->irq_msk_offset);
+}
+
+static int sx_common_disable_irq(struct sx_common_data *data, unsigned int irq)
+{
+	if (!data->client->irq)
+		return 0;
+	return regmap_update_bits(data->regmap, data->chip_info->reg_irq_msk,
+				  irq << data->chip_info->irq_msk_offset, 0);
+}
+
+static int sx_common_update_chan_en(struct sx_common_data *data,
+				    unsigned long chan_read,
+				    unsigned long chan_event)
+{
+	int ret;
+	unsigned long channels = chan_read | chan_event;
+
+	if ((data->chan_read | data->chan_event) != channels) {
+		ret = regmap_update_bits(data->regmap,
+					 data->chip_info->reg_enable_chan,
+					 data->chip_info->mask_enable_chan,
+					 channels);
+		if (ret)
+			return ret;
+	}
+	data->chan_read = chan_read;
+	data->chan_event = chan_event;
+	return 0;
+}
+
+static int sx_common_get_read_channel(struct sx_common_data *data, int channel)
+{
+	return sx_common_update_chan_en(data, data->chan_read | BIT(channel),
+				     data->chan_event);
+}
+
+static int sx_common_put_read_channel(struct sx_common_data *data, int channel)
+{
+	return sx_common_update_chan_en(data, data->chan_read & ~BIT(channel),
+				     data->chan_event);
+}
+
+static int sx_common_get_event_channel(struct sx_common_data *data, int channel)
+{
+	return sx_common_update_chan_en(data, data->chan_read,
+				     data->chan_event | BIT(channel));
+}
+
+static int sx_common_put_event_channel(struct sx_common_data *data, int channel)
+{
+	return sx_common_update_chan_en(data, data->chan_read,
+				     data->chan_event & ~BIT(channel));
+}
+
+/**
+ * sx_common_read_proximity() - Read raw proximity value.
+ * @data:	Internal data
+ * @chan:	Channel to read
+ * @val:	pointer to return read value.
+ *
+ * Request a conversion, wait for the sensor to be ready and
+ * return the raw proximity value.
+ */
+int sx_common_read_proximity(struct sx_common_data *data,
+			     const struct iio_chan_spec *chan, int *val)
+{
+	int ret;
+	__be16 rawval;
+
+	mutex_lock(&data->mutex);
+
+	ret = sx_common_get_read_channel(data, chan->channel);
+	if (ret)
+		goto out;
+
+	ret = sx_common_enable_irq(data, SX_COMMON_CONVDONE_IRQ);
+	if (ret)
+		goto out_put_channel;
+
+	mutex_unlock(&data->mutex);
+
+	if (data->client->irq) {
+		ret = wait_for_completion_interruptible(&data->completion);
+		reinit_completion(&data->completion);
+	} else {
+		ret = data->chip_info->ops.wait_for_sample(data);
+	}
+
+	mutex_lock(&data->mutex);
+
+	if (ret)
+		goto out_disable_irq;
+
+	ret = data->chip_info->ops.read_prox_data(data, chan, &rawval);
+	if (ret)
+		goto out_disable_irq;
+
+	*val = sign_extend32(be16_to_cpu(rawval), chan->scan_type.realbits - 1);
+
+	ret = sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
+	if (ret)
+		goto out_put_channel;
+
+	ret = sx_common_put_read_channel(data, chan->channel);
+	if (ret)
+		goto out;
+
+	mutex_unlock(&data->mutex);
+
+	return IIO_VAL_INT;
+
+out_disable_irq:
+	sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
+out_put_channel:
+	sx_common_put_read_channel(data, chan->channel);
+out:
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(sx_common_read_proximity, SEMTECH_PROX);
+
+/**
+ * sx_common_read_event_config() - Configure event setting.
+ * @indio_dev:	iio device object
+ * @chan:	Channel to read
+ * @type:	Type of event (unused)
+ * @dir:	Direction of event (unused)
+ *
+ * return if the given channel is used for event gathering.
+ */
+int sx_common_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 sx_common_data *data = iio_priv(indio_dev);
+
+	return !!(data->chan_event & BIT(chan->channel));
+}
+EXPORT_SYMBOL_NS_GPL(sx_common_read_event_config, SEMTECH_PROX);
+
+/**
+ * sx_common_write_event_config() - Configure event setting.
+ * @indio_dev:	iio device object
+ * @chan:	Channel to enable
+ * @type:	Type of event (unused)
+ * @dir:	Direction of event (unused)
+ * @state:	State of the event.
+ *
+ * Enable/Disable event on a given channel.
+ */
+int sx_common_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 sx_common_data *data = iio_priv(indio_dev);
+	unsigned int eventirq = SX_COMMON_FAR_IRQ | SX_COMMON_CLOSE_IRQ;
+	int ret;
+
+	/* If the state hasn't changed, there's nothing to do. */
+	if (!!(data->chan_event & BIT(chan->channel)) == state)
+		return 0;
+
+	mutex_lock(&data->mutex);
+	if (state) {
+		ret = sx_common_get_event_channel(data, chan->channel);
+		if (ret)
+			goto out_unlock;
+		if (!(data->chan_event & ~BIT(chan->channel))) {
+			ret = sx_common_enable_irq(data, eventirq);
+			if (ret)
+				sx_common_put_event_channel(data, chan->channel);
+		}
+	} else {
+		ret = sx_common_put_event_channel(data, chan->channel);
+		if (ret)
+			goto out_unlock;
+		if (!data->chan_event) {
+			ret = sx_common_disable_irq(data, eventirq);
+			if (ret)
+				sx_common_get_event_channel(data, chan->channel);
+		}
+	}
+
+out_unlock:
+	mutex_unlock(&data->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(sx_common_write_event_config, SEMTECH_PROX);
+
+static int sx_common_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct sx_common_data *data = iio_priv(indio_dev);
+	int ret = 0;
+
+	mutex_lock(&data->mutex);
+
+	if (state)
+		ret = sx_common_enable_irq(data, SX_COMMON_CONVDONE_IRQ);
+	else if (!data->chan_read)
+		ret = sx_common_disable_irq(data, SX_COMMON_CONVDONE_IRQ);
+	if (ret)
+		goto out;
+
+	data->trigger_enabled = state;
+
+out:
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static const struct iio_trigger_ops sx_common_trigger_ops = {
+	.set_trigger_state = sx_common_set_trigger_state,
+};
+
+static irqreturn_t sx_common_irq_thread_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct sx_common_data *data = iio_priv(indio_dev);
+	int ret;
+	unsigned int val;
+
+	mutex_lock(&data->mutex);
+
+	ret = regmap_read(data->regmap, SX_COMMON_REG_IRQ_SRC, &val);
+	if (ret) {
+		dev_err(&data->client->dev, "i2c transfer error in irq\n");
+		goto out;
+	}
+
+	if (val & ((SX_COMMON_FAR_IRQ | SX_COMMON_CLOSE_IRQ) << data->chip_info->irq_msk_offset))
+		sx_common_push_events(indio_dev);
+
+	if (val & (SX_COMMON_CONVDONE_IRQ << data->chip_info->irq_msk_offset))
+		complete(&data->completion);
+
+out:
+	mutex_unlock(&data->mutex);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sx_common_trigger_handler(int irq, void *private)
+{
+	struct iio_poll_func *pf = private;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct sx_common_data *data = iio_priv(indio_dev);
+	__be16 val;
+	int bit, ret, i = 0;
+
+	mutex_lock(&data->mutex);
+
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
+			 indio_dev->masklength) {
+		ret = data->chip_info->ops.read_prox_data(data,
+						     &indio_dev->channels[bit],
+						     &val);
+		if (ret)
+			goto out;
+
+		data->buffer.channels[i++] = val;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer,
+					   pf->timestamp);
+
+out:
+	mutex_unlock(&data->mutex);
+
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int sx_common_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct sx_common_data *data = iio_priv(indio_dev);
+	unsigned long channels = 0;
+	int bit, ret;
+
+	mutex_lock(&data->mutex);
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
+			 indio_dev->masklength)
+		__set_bit(indio_dev->channels[bit].channel, &channels);
+
+	ret = sx_common_update_chan_en(data, channels, data->chan_event);
+	mutex_unlock(&data->mutex);
+	return ret;
+}
+
+static int sx_common_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct sx_common_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = sx_common_update_chan_en(data, 0, data->chan_event);
+	mutex_unlock(&data->mutex);
+	return ret;
+}
+
+static const struct iio_buffer_setup_ops sx_common_buffer_setup_ops = {
+	.preenable = sx_common_buffer_preenable,
+	.postdisable = sx_common_buffer_postdisable,
+};
+
+static void sx_common_regulator_disable(void *_data)
+{
+	struct sx_common_data *data = _data;
+
+	regulator_bulk_disable(ARRAY_SIZE(data->supplies), data->supplies);
+}
+
+#define SX_COMMON_SOFT_RESET				0xde
+
+static int sx_common_init_device(struct device *dev, struct iio_dev *indio_dev)
+{
+	struct sx_common_data *data = iio_priv(indio_dev);
+	struct sx_common_reg_default tmp;
+	const struct sx_common_reg_default *initval;
+	int ret;
+	unsigned int i, val;
+
+	ret = regmap_write(data->regmap, data->chip_info->reg_reset,
+			   SX_COMMON_SOFT_RESET);
+	if (ret)
+		return ret;
+
+	usleep_range(1000, 2000); /* power-up time is ~1ms. */
+
+	/* Clear reset interrupt state by reading SX_COMMON_REG_IRQ_SRC. */
+	ret = regmap_read(data->regmap, SX_COMMON_REG_IRQ_SRC, &val);
+	if (ret)
+		return ret;
+
+	/* Program defaults from constant or BIOS. */
+	for (i = 0; i < data->chip_info->num_default_regs; i++) {
+		initval = data->chip_info->ops.get_default_reg(dev, i, &tmp);
+		ret = regmap_write(data->regmap, initval->reg, initval->def);
+		if (ret)
+			return ret;
+	}
+
+	return data->chip_info->ops.init_compensation(indio_dev);
+}
+
+/**
+ * sx_common_probe() - Common setup for Semtech SAR sensor
+ * @client:		I2C client object
+ * @chip_info:		Semtech sensor chip information.
+ * @regmap_config:	Sensor registers map configuration.
+ */
+int sx_common_probe(struct i2c_client *client,
+		    const struct sx_common_chip_info *chip_info,
+		    const struct regmap_config *regmap_config)
+{
+	struct device *dev = &client->dev;
+	struct iio_dev *indio_dev;
+	struct sx_common_data *data;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+
+	data->chip_info = chip_info;
+	data->client = client;
+	data->supplies[0].supply = "vdd";
+	data->supplies[1].supply = "svdd";
+	mutex_init(&data->mutex);
+	init_completion(&data->completion);
+
+	data->regmap = devm_regmap_init_i2c(client, regmap_config);
+	if (IS_ERR(data->regmap))
+		return dev_err_probe(dev, PTR_ERR(data->regmap),
+				     "Could init register map\n");
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->supplies),
+				      data->supplies);
+	if (ret)
+		return dev_err_probe(dev, ret, "Unable to get regulators\n");
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(data->supplies), data->supplies);
+	if (ret)
+		return dev_err_probe(dev, ret, "Unable to enable regulators\n");
+
+	/* Must wait for Tpor time after initial power up */
+	usleep_range(1000, 1100);
+
+	ret = devm_add_action_or_reset(dev, sx_common_regulator_disable, data);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Unable to register regulators deleter\n");
+
+	ret = data->chip_info->ops.check_whoami(dev, indio_dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "error reading WHOAMI\n");
+
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	indio_dev->channels =  data->chip_info->iio_channels;
+	indio_dev->num_channels = data->chip_info->num_iio_channels;
+	indio_dev->info = &data->chip_info->iio_info;
+
+	i2c_set_clientdata(client, indio_dev);
+
+	ret = sx_common_init_device(dev, indio_dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Unable to initialize sensor\n");
+
+	if (client->irq) {
+		ret = devm_request_threaded_irq(dev, client->irq,
+						sx_common_irq_handler,
+						sx_common_irq_thread_handler,
+						IRQF_ONESHOT,
+						"sx_event", indio_dev);
+		if (ret)
+			return dev_err_probe(dev, ret, "No IRQ\n");
+
+		data->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+						    indio_dev->name,
+						    iio_device_id(indio_dev));
+		if (!data->trig)
+			return -ENOMEM;
+
+		data->trig->ops = &sx_common_trigger_ops;
+		iio_trigger_set_drvdata(data->trig, indio_dev);
+
+		ret = devm_iio_trigger_register(dev, data->trig);
+		if (ret)
+			return ret;
+	}
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+					      iio_pollfunc_store_time,
+					      sx_common_trigger_handler,
+					      &sx_common_buffer_setup_ops);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_NS_GPL(sx_common_probe, SEMTECH_PROX);
+
+MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
+MODULE_DESCRIPTION("Common functions and structures for Semtech sensor");
+MODULE_LICENSE("GPL v2");