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![Stephen Boyd](/assets/img/avatar_default.png)
Add support for a ChromeOS EC proximity driver that exposes a "front" proximity sensor via the IIO subsystem. The EC decides when front proximity is near and sets an MKBP switch 'EC_MKBP_FRONT_PROXIMITY' to notify the kernel of proximity. Similarly, when proximity detects something far away it sets the switch bit to 0. For now this driver exposes a single sensor, but it could be expanded in the future via more MKBP bits if desired. Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Benson Leung <bleung@chromium.org> Cc: Guenter Roeck <groeck@chromium.org> Cc: Douglas Anderson <dianders@chromium.org> Cc: Gwendal Grignou <gwendal@chromium.org> Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Gwendal Grignou <gwendal@chromium.org> Link: https://lore.kernel.org/r/20210211024601.1963379-4-swboyd@chromium.org Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
271 lines
7.1 KiB
C
271 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Driver for cros-ec proximity sensor exposed through MKBP switch
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*
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* Copyright 2021 Google LLC.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/notifier.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/platform_data/cros_ec_commands.h>
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#include <linux/platform_data/cros_ec_proto.h>
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#include <linux/iio/events.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <asm/unaligned.h>
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struct cros_ec_mkbp_proximity_data {
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struct cros_ec_device *ec;
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struct iio_dev *indio_dev;
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struct mutex lock;
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struct notifier_block notifier;
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int last_proximity;
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bool enabled;
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};
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static const struct iio_event_spec cros_ec_mkbp_proximity_events[] = {
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{
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.type = IIO_EV_TYPE_THRESH,
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.dir = IIO_EV_DIR_EITHER,
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.mask_separate = BIT(IIO_EV_INFO_ENABLE),
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},
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};
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static const struct iio_chan_spec cros_ec_mkbp_proximity_chan_spec[] = {
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{
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.type = IIO_PROXIMITY,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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.event_spec = cros_ec_mkbp_proximity_events,
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.num_event_specs = ARRAY_SIZE(cros_ec_mkbp_proximity_events),
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},
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};
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static int cros_ec_mkbp_proximity_parse_state(const void *data)
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{
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u32 switches = get_unaligned_le32(data);
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return !!(switches & BIT(EC_MKBP_FRONT_PROXIMITY));
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}
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static int cros_ec_mkbp_proximity_query(struct cros_ec_device *ec_dev,
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int *state)
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{
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struct {
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struct cros_ec_command msg;
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union {
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struct ec_params_mkbp_info params;
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u32 switches;
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};
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} __packed buf = { };
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struct ec_params_mkbp_info *params = &buf.params;
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struct cros_ec_command *msg = &buf.msg;
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u32 *switches = &buf.switches;
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size_t insize = sizeof(*switches);
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int ret;
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msg->command = EC_CMD_MKBP_INFO;
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msg->version = 1;
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msg->outsize = sizeof(*params);
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msg->insize = insize;
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params->info_type = EC_MKBP_INFO_CURRENT;
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params->event_type = EC_MKBP_EVENT_SWITCH;
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ret = cros_ec_cmd_xfer_status(ec_dev, msg);
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if (ret < 0)
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return ret;
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if (ret != insize) {
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dev_warn(ec_dev->dev, "wrong result size: %d != %zu\n", ret,
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insize);
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return -EPROTO;
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}
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*state = cros_ec_mkbp_proximity_parse_state(switches);
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return IIO_VAL_INT;
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}
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static void cros_ec_mkbp_proximity_push_event(struct cros_ec_mkbp_proximity_data *data, int state)
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{
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s64 timestamp;
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u64 ev;
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int dir;
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struct iio_dev *indio_dev = data->indio_dev;
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struct cros_ec_device *ec = data->ec;
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mutex_lock(&data->lock);
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if (state != data->last_proximity) {
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if (data->enabled) {
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timestamp = ktime_to_ns(ec->last_event_time);
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if (iio_device_get_clock(indio_dev) != CLOCK_BOOTTIME)
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timestamp = iio_get_time_ns(indio_dev);
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dir = state ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
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ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
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IIO_EV_TYPE_THRESH, dir);
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iio_push_event(indio_dev, ev, timestamp);
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}
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data->last_proximity = state;
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}
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mutex_unlock(&data->lock);
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}
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static int cros_ec_mkbp_proximity_notify(struct notifier_block *nb,
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unsigned long queued_during_suspend,
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void *_ec)
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{
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struct cros_ec_mkbp_proximity_data *data;
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struct cros_ec_device *ec = _ec;
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u8 event_type = ec->event_data.event_type & EC_MKBP_EVENT_TYPE_MASK;
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void *switches;
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int state;
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if (event_type == EC_MKBP_EVENT_SWITCH) {
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data = container_of(nb, struct cros_ec_mkbp_proximity_data,
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notifier);
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switches = &ec->event_data.data.switches;
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state = cros_ec_mkbp_proximity_parse_state(switches);
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cros_ec_mkbp_proximity_push_event(data, state);
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}
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return NOTIFY_OK;
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}
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static int cros_ec_mkbp_proximity_read_raw(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan, int *val,
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int *val2, long mask)
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{
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struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
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struct cros_ec_device *ec = data->ec;
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if (chan->type == IIO_PROXIMITY && mask == IIO_CHAN_INFO_RAW)
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return cros_ec_mkbp_proximity_query(ec, val);
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return -EINVAL;
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}
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static int cros_ec_mkbp_proximity_read_event_config(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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enum iio_event_type type,
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enum iio_event_direction dir)
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{
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struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
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return data->enabled;
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}
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static int cros_ec_mkbp_proximity_write_event_config(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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enum iio_event_type type,
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enum iio_event_direction dir, int state)
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{
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struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
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mutex_lock(&data->lock);
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data->enabled = state;
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mutex_unlock(&data->lock);
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return 0;
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}
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static const struct iio_info cros_ec_mkbp_proximity_info = {
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.read_raw = cros_ec_mkbp_proximity_read_raw,
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.read_event_config = cros_ec_mkbp_proximity_read_event_config,
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.write_event_config = cros_ec_mkbp_proximity_write_event_config,
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};
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static __maybe_unused int cros_ec_mkbp_proximity_resume(struct device *dev)
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{
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struct cros_ec_mkbp_proximity_data *data = dev_get_drvdata(dev);
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struct cros_ec_device *ec = data->ec;
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int ret, state;
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ret = cros_ec_mkbp_proximity_query(ec, &state);
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if (ret < 0) {
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dev_warn(dev, "failed to fetch proximity state on resume: %d\n",
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ret);
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} else {
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cros_ec_mkbp_proximity_push_event(data, state);
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}
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(cros_ec_mkbp_proximity_pm_ops, NULL,
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cros_ec_mkbp_proximity_resume);
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static int cros_ec_mkbp_proximity_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct cros_ec_device *ec = dev_get_drvdata(dev->parent);
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struct iio_dev *indio_dev;
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struct cros_ec_mkbp_proximity_data *data;
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int ret;
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indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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data = iio_priv(indio_dev);
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data->ec = ec;
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data->indio_dev = indio_dev;
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data->last_proximity = -1; /* Unknown to start */
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mutex_init(&data->lock);
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platform_set_drvdata(pdev, data);
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indio_dev->name = dev->driver->name;
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indio_dev->info = &cros_ec_mkbp_proximity_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = cros_ec_mkbp_proximity_chan_spec;
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indio_dev->num_channels = ARRAY_SIZE(cros_ec_mkbp_proximity_chan_spec);
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ret = devm_iio_device_register(dev, indio_dev);
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if (ret)
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return ret;
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data->notifier.notifier_call = cros_ec_mkbp_proximity_notify;
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blocking_notifier_chain_register(&ec->event_notifier, &data->notifier);
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return 0;
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}
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static int cros_ec_mkbp_proximity_remove(struct platform_device *pdev)
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{
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struct cros_ec_mkbp_proximity_data *data = platform_get_drvdata(pdev);
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struct cros_ec_device *ec = data->ec;
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blocking_notifier_chain_unregister(&ec->event_notifier,
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&data->notifier);
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return 0;
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}
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static const struct of_device_id cros_ec_mkbp_proximity_of_match[] = {
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{ .compatible = "google,cros-ec-mkbp-proximity" },
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{}
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};
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MODULE_DEVICE_TABLE(of, cros_ec_mkbp_proximity_of_match);
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static struct platform_driver cros_ec_mkbp_proximity_driver = {
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.driver = {
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.name = "cros-ec-mkbp-proximity",
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.of_match_table = cros_ec_mkbp_proximity_of_match,
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.pm = &cros_ec_mkbp_proximity_pm_ops,
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},
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.probe = cros_ec_mkbp_proximity_probe,
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.remove = cros_ec_mkbp_proximity_remove,
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};
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module_platform_driver(cros_ec_mkbp_proximity_driver);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("ChromeOS EC MKBP proximity sensor driver");
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