diff options
Diffstat (limited to 'drivers/iio/proximity/cros_ec_mkbp_proximity.c')
| -rw-r--r-- | drivers/iio/proximity/cros_ec_mkbp_proximity.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/iio/proximity/cros_ec_mkbp_proximity.c b/drivers/iio/proximity/cros_ec_mkbp_proximity.c new file mode 100644 index 000000000..571ea1812 --- /dev/null +++ b/drivers/iio/proximity/cros_ec_mkbp_proximity.c @@ -0,0 +1,271 @@ +// 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 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 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 = pm_sleep_ptr(&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"); |