// 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/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.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 <linux/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 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 DEFINE_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 void 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);
}
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 = pm_sleep_ptr(&cros_ec_mkbp_proximity_pm_ops),
},
.probe = cros_ec_mkbp_proximity_probe,
.remove_new = 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");
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