cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cros_ec_lid_angle.c (3587B)

      1// SPDX-License-Identifier: GPL-2.0
      2
      3/*
      4 * cros_ec_lid_angle - Driver for CrOS EC lid angle sensor.
      5 *
      6 * Copyright 2018 Google, Inc
      7 *
      8 * This driver uses the cros-ec interface to communicate with the Chrome OS
      9 * EC about counter sensors. Counters are presented through
     10 * iio sysfs.
     11 */
     12
     13#include <linux/delay.h>
     14#include <linux/device.h>
     15#include <linux/iio/buffer.h>
     16#include <linux/iio/common/cros_ec_sensors_core.h>
     17#include <linux/iio/iio.h>
     18#include <linux/iio/kfifo_buf.h>
     19#include <linux/iio/trigger.h>
     20#include <linux/iio/triggered_buffer.h>
     21#include <linux/iio/trigger_consumer.h>
     22#include <linux/kernel.h>
     23#include <linux/module.h>
     24#include <linux/platform_data/cros_ec_commands.h>
     25#include <linux/platform_device.h>
     26#include <linux/slab.h>
     27
     28#define DRV_NAME "cros-ec-lid-angle"
     29
     30/*
     31 * One channel for the lid angle, the other for timestamp.
     32 */
     33static const struct iio_chan_spec cros_ec_lid_angle_channels[] = {
     34	{
     35		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
     36		.scan_type.realbits = CROS_EC_SENSOR_BITS,
     37		.scan_type.storagebits = CROS_EC_SENSOR_BITS,
     38		.scan_type.sign = 'u',
     39		.type = IIO_ANGL
     40	},
     41	IIO_CHAN_SOFT_TIMESTAMP(1)
     42};
     43
     44/* State data for ec_sensors iio driver. */
     45struct cros_ec_lid_angle_state {
     46	/* Shared by all sensors */
     47	struct cros_ec_sensors_core_state core;
     48};
     49
     50static int cros_ec_sensors_read_lid_angle(struct iio_dev *indio_dev,
     51					  unsigned long scan_mask, s16 *data)
     52{
     53	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
     54	int ret;
     55
     56	st->param.cmd = MOTIONSENSE_CMD_LID_ANGLE;
     57	ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->lid_angle));
     58	if (ret) {
     59		dev_warn(&indio_dev->dev, "Unable to read lid angle\n");
     60		return ret;
     61	}
     62
     63	*data = st->resp->lid_angle.value;
     64	return 0;
     65}
     66
     67static int cros_ec_lid_angle_read(struct iio_dev *indio_dev,
     68				    struct iio_chan_spec const *chan,
     69				    int *val, int *val2, long mask)
     70{
     71	struct cros_ec_lid_angle_state *st = iio_priv(indio_dev);
     72	s16 data;
     73	int ret;
     74
     75	mutex_lock(&st->core.cmd_lock);
     76	ret = cros_ec_sensors_read_lid_angle(indio_dev, 1, &data);
     77	if (ret == 0) {
     78		*val = data;
     79		ret = IIO_VAL_INT;
     80	}
     81	mutex_unlock(&st->core.cmd_lock);
     82	return ret;
     83}
     84
     85static const struct iio_info cros_ec_lid_angle_info = {
     86	.read_raw = &cros_ec_lid_angle_read,
     87};
     88
     89static int cros_ec_lid_angle_probe(struct platform_device *pdev)
     90{
     91	struct device *dev = &pdev->dev;
     92	struct iio_dev *indio_dev;
     93	struct cros_ec_lid_angle_state *state;
     94	int ret;
     95
     96	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
     97	if (!indio_dev)
     98		return -ENOMEM;
     99
    100	ret = cros_ec_sensors_core_init(pdev, indio_dev, false, NULL, NULL);
    101	if (ret)
    102		return ret;
    103
    104	indio_dev->info = &cros_ec_lid_angle_info;
    105	state = iio_priv(indio_dev);
    106	indio_dev->channels = cros_ec_lid_angle_channels;
    107	indio_dev->num_channels = ARRAY_SIZE(cros_ec_lid_angle_channels);
    108
    109	state->core.read_ec_sensors_data = cros_ec_sensors_read_lid_angle;
    110
    111	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
    112			cros_ec_sensors_capture, NULL);
    113	if (ret)
    114		return ret;
    115
    116	return devm_iio_device_register(dev, indio_dev);
    117}
    118
    119static const struct platform_device_id cros_ec_lid_angle_ids[] = {
    120	{
    121		.name = DRV_NAME,
    122	},
    123	{ /* sentinel */ }
    124};
    125MODULE_DEVICE_TABLE(platform, cros_ec_lid_angle_ids);
    126
    127static struct platform_driver cros_ec_lid_angle_platform_driver = {
    128	.driver = {
    129		.name	= DRV_NAME,
    130	},
    131	.probe		= cros_ec_lid_angle_probe,
    132	.id_table	= cros_ec_lid_angle_ids,
    133};
    134module_platform_driver(cros_ec_lid_angle_platform_driver);
    135
    136MODULE_DESCRIPTION("ChromeOS EC driver for reporting convertible lid angle.");
    137MODULE_LICENSE("GPL v2");