--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for cros-ec proximity sensor exposed through MKBP switch
+ *
+ * Copyright 2021 Google LLC.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include <asm/unaligned.h>
+
+struct cros_ec_mkbp_proximity_data {
+ struct cros_ec_device *ec;
+ struct iio_dev *indio_dev;
+ struct mutex lock;
+ struct notifier_block notifier;
+ int last_proximity;
+ bool enabled;
+};
+
+static const struct iio_event_spec cros_ec_mkbp_proximity_events[] = {
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_EITHER,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE),
+ },
+};
+
+static const struct iio_chan_spec cros_ec_mkbp_proximity_chan_spec[] = {
+ {
+ .type = IIO_PROXIMITY,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .event_spec = cros_ec_mkbp_proximity_events,
+ .num_event_specs = ARRAY_SIZE(cros_ec_mkbp_proximity_events),
+ },
+};
+
+static int cros_ec_mkbp_proximity_parse_state(const void *data)
+{
+ u32 switches = get_unaligned_le32(data);
+
+ return !!(switches & BIT(EC_MKBP_FRONT_PROXIMITY));
+}
+
+static int cros_ec_mkbp_proximity_query(struct cros_ec_device *ec_dev,
+ int *state)
+{
+ struct {
+ struct cros_ec_command msg;
+ union {
+ struct ec_params_mkbp_info params;
+ u32 switches;
+ };
+ } __packed buf = { };
+ struct ec_params_mkbp_info *params = &buf.params;
+ struct cros_ec_command *msg = &buf.msg;
+ u32 *switches = &buf.switches;
+ size_t insize = sizeof(*switches);
+ int ret;
+
+ msg->command = EC_CMD_MKBP_INFO;
+ msg->version = 1;
+ msg->outsize = sizeof(*params);
+ msg->insize = insize;
+
+ params->info_type = EC_MKBP_INFO_CURRENT;
+ params->event_type = EC_MKBP_EVENT_SWITCH;
+
+ ret = cros_ec_cmd_xfer_status(ec_dev, msg);
+ if (ret < 0)
+ return ret;
+
+ if (ret != insize) {
+ dev_warn(ec_dev->dev, "wrong result size: %d != %zu\n", ret,
+ insize);
+ return -EPROTO;
+ }
+
+ *state = cros_ec_mkbp_proximity_parse_state(switches);
+ return IIO_VAL_INT;
+}
+
+static void cros_ec_mkbp_proximity_push_event(struct cros_ec_mkbp_proximity_data *data, int state)
+{
+ s64 timestamp;
+ u64 ev;
+ int dir;
+ struct iio_dev *indio_dev = data->indio_dev;
+ struct cros_ec_device *ec = data->ec;
+
+ mutex_lock(&data->lock);
+ if (state != data->last_proximity) {
+ if (data->enabled) {
+ timestamp = ktime_to_ns(ec->last_event_time);
+ if (iio_device_get_clock(indio_dev) != CLOCK_BOOTTIME)
+ timestamp = iio_get_time_ns(indio_dev);
+
+ dir = state ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
+ ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+ IIO_EV_TYPE_THRESH, dir);
+ iio_push_event(indio_dev, ev, timestamp);
+ }
+ data->last_proximity = state;
+ }
+ mutex_unlock(&data->lock);
+}
+
+static int cros_ec_mkbp_proximity_notify(struct notifier_block *nb,
+ unsigned long queued_during_suspend,
+ void *_ec)
+{
+ struct cros_ec_mkbp_proximity_data *data;
+ struct cros_ec_device *ec = _ec;
+ u8 event_type = ec->event_data.event_type & EC_MKBP_EVENT_TYPE_MASK;
+ void *switches;
+ int state;
+
+ if (event_type == EC_MKBP_EVENT_SWITCH) {
+ data = container_of(nb, struct cros_ec_mkbp_proximity_data,
+ notifier);
+
+ switches = &ec->event_data.data.switches;
+ state = cros_ec_mkbp_proximity_parse_state(switches);
+ cros_ec_mkbp_proximity_push_event(data, state);
+ }
+
+ return NOTIFY_OK;
+}
+
+static int cros_ec_mkbp_proximity_read_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int *val,
+ int *val2, long mask)
+{
+ struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
+ struct cros_ec_device *ec = data->ec;
+
+ if (chan->type == IIO_PROXIMITY && mask == IIO_CHAN_INFO_RAW)
+ return cros_ec_mkbp_proximity_query(ec, val);
+
+ return -EINVAL;
+}
+
+static int cros_ec_mkbp_proximity_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 cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
+
+ return data->enabled;
+}
+
+static int cros_ec_mkbp_proximity_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 cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
+
+ mutex_lock(&data->lock);
+ data->enabled = state;
+ mutex_unlock(&data->lock);
+
+ return 0;
+}
+
+static const struct iio_info cros_ec_mkbp_proximity_info = {
+ .read_raw = cros_ec_mkbp_proximity_read_raw,
+ .read_event_config = cros_ec_mkbp_proximity_read_event_config,
+ .write_event_config = cros_ec_mkbp_proximity_write_event_config,
+};
+
+static __maybe_unused int cros_ec_mkbp_proximity_resume(struct device *dev)
+{
+ struct cros_ec_mkbp_proximity_data *data = dev_get_drvdata(dev);
+ struct cros_ec_device *ec = data->ec;
+ int ret, state;
+
+ ret = cros_ec_mkbp_proximity_query(ec, &state);
+ if (ret < 0) {
+ dev_warn(dev, "failed to fetch proximity state on resume: %d\n",
+ ret);
+ } else {
+ cros_ec_mkbp_proximity_push_event(data, state);
+ }
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(cros_ec_mkbp_proximity_pm_ops, NULL,
+ cros_ec_mkbp_proximity_resume);
+
+static int cros_ec_mkbp_proximity_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct cros_ec_device *ec = dev_get_drvdata(dev->parent);
+ struct iio_dev *indio_dev;
+ struct cros_ec_mkbp_proximity_data *data;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ data->ec = ec;
+ data->indio_dev = indio_dev;
+ data->last_proximity = -1; /* Unknown to start */
+ mutex_init(&data->lock);
+ platform_set_drvdata(pdev, data);
+
+ indio_dev->name = dev->driver->name;
+ indio_dev->info = &cros_ec_mkbp_proximity_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = cros_ec_mkbp_proximity_chan_spec;
+ indio_dev->num_channels = ARRAY_SIZE(cros_ec_mkbp_proximity_chan_spec);
+
+ ret = devm_iio_device_register(dev, indio_dev);
+ if (ret)
+ return ret;
+
+ data->notifier.notifier_call = cros_ec_mkbp_proximity_notify;
+ blocking_notifier_chain_register(&ec->event_notifier, &data->notifier);
+
+ return 0;
+}
+
+static int cros_ec_mkbp_proximity_remove(struct platform_device *pdev)
+{
+ struct cros_ec_mkbp_proximity_data *data = platform_get_drvdata(pdev);
+ struct cros_ec_device *ec = data->ec;
+
+ blocking_notifier_chain_unregister(&ec->event_notifier,
+ &data->notifier);
+
+ return 0;
+}
+
+static const struct of_device_id cros_ec_mkbp_proximity_of_match[] = {
+ { .compatible = "google,cros-ec-mkbp-proximity" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, cros_ec_mkbp_proximity_of_match);
+
+static struct platform_driver cros_ec_mkbp_proximity_driver = {
+ .driver = {
+ .name = "cros-ec-mkbp-proximity",
+ .of_match_table = cros_ec_mkbp_proximity_of_match,
+ .pm = &cros_ec_mkbp_proximity_pm_ops,
+ },
+ .probe = cros_ec_mkbp_proximity_probe,
+ .remove = cros_ec_mkbp_proximity_remove,
+};
+module_platform_driver(cros_ec_mkbp_proximity_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ChromeOS EC MKBP proximity sensor driver");
projects / linux-block.git / commitdiff