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-rw-r--r--drivers/iio/proximity/sx_common.c569
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");