| /* |
| * cros_ec_sensors_sync - Driver for synchronisation sensor behind CrOS EC. |
| * |
| * Copyright 2018 Google, Inc |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * This driver uses the cros-ec interface to communicate with the Chrome OS |
| * EC about counter sensors. Counters are presented through |
| * iio sysfs. |
| */ |
| |
| #include <linux/delay.h> |
| #include <linux/device.h> |
| #include <linux/iio/buffer.h> |
| #include <linux/iio/common/cros_ec_sensors_core.h> |
| #include <linux/iio/iio.h> |
| #include <linux/iio/kfifo_buf.h> |
| #include <linux/iio/trigger.h> |
| #include <linux/iio/triggered_buffer.h> |
| #include <linux/iio/trigger_consumer.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/platform_data/cros_ec_commands.h> |
| #include <linux/platform_data/cros_ec_proto.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| |
| /* |
| * One channel for timestamp. |
| */ |
| #define MAX_CHANNELS 1 |
| |
| /* State data for ec_sensors iio driver. */ |
| struct cros_ec_sensors_sync_state { |
| /* Shared by all sensors */ |
| struct cros_ec_sensors_core_state core; |
| |
| struct iio_chan_spec channels[MAX_CHANNELS]; |
| }; |
| |
| static int cros_ec_sensors_sync_read(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long mask) |
| { |
| struct cros_ec_sensors_sync_state *st = iio_priv(indio_dev); |
| int ret; |
| |
| mutex_lock(&st->core.cmd_lock); |
| ret = cros_ec_sensors_core_read(&st->core, chan, val, val2, mask); |
| mutex_unlock(&st->core.cmd_lock); |
| return ret; |
| } |
| |
| static int cros_ec_sensors_write(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int val, int val2, long mask) |
| { |
| struct cros_ec_sensors_sync_state *st = iio_priv(indio_dev); |
| int ret; |
| |
| mutex_lock(&st->core.cmd_lock); |
| |
| ret = cros_ec_sensors_core_write( |
| &st->core, chan, val, val2, mask); |
| |
| mutex_unlock(&st->core.cmd_lock); |
| return ret; |
| } |
| |
| static const struct iio_info cros_ec_sensors_sync_info = { |
| .read_raw = &cros_ec_sensors_sync_read, |
| .write_raw = &cros_ec_sensors_write, |
| .read_avail = &cros_ec_sensors_core_read_avail, |
| }; |
| |
| static int cros_ec_sensors_sync_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct iio_dev *indio_dev; |
| struct cros_ec_sensors_sync_state *state; |
| struct iio_chan_spec *channel; |
| int ret; |
| |
| indio_dev = devm_iio_device_alloc(dev, sizeof(*state)); |
| if (!indio_dev) |
| return -ENOMEM; |
| |
| ret = cros_ec_sensors_core_init(pdev, indio_dev, true, |
| cros_ec_sensors_capture); |
| if (ret) |
| return ret; |
| |
| indio_dev->info = &cros_ec_sensors_sync_info; |
| state = iio_priv(indio_dev); |
| /* |
| * Sync sensor notion of frequencies is either on or off. |
| * EC reports min and max as 1, that would translate in 1 mHz. |
| * Force it to 1 (..HZ), more readable. |
| * For the EC, any frequencies different from 0 means the sync sensor is |
| * enabled. |
| */ |
| state->core.frequencies[2] = state->core.frequencies[4] = 1; |
| state->core.frequencies[3] = state->core.frequencies[5] = 0; |
| |
| channel = state->channels; |
| channel->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ); |
| channel->info_mask_shared_by_all_available = |
| BIT(IIO_CHAN_INFO_SAMP_FREQ); |
| channel->type = IIO_TIMESTAMP; |
| channel->channel = -1; |
| channel->scan_index = 1; |
| channel->scan_type.sign = 's'; |
| channel->scan_type.realbits = 64; |
| channel->scan_type.storagebits = 64; |
| |
| indio_dev->channels = state->channels; |
| indio_dev->num_channels = MAX_CHANNELS; |
| |
| state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd; |
| |
| return cros_ec_sensors_core_register(dev, indio_dev, |
| cros_ec_sensors_push_data); |
| } |
| |
| static const struct platform_device_id cros_ec_sensors_sync_ids[] = { |
| { |
| .name = "cros-ec-sync", |
| }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(platform, cros_ec_sensors_sync_ids); |
| |
| static struct platform_driver cros_ec_sensors_sync_platform_driver = { |
| .driver = { |
| .name = "cros-ec-sync", |
| }, |
| .probe = cros_ec_sensors_sync_probe, |
| .id_table = cros_ec_sensors_sync_ids, |
| }; |
| module_platform_driver(cros_ec_sensors_sync_platform_driver); |
| |
| MODULE_DESCRIPTION("ChromeOS EC synchronisation sensor driver"); |
| MODULE_LICENSE("GPL v2"); |