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_baro.c (5332B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * cros_ec_baro - Driver for barometer sensor behind CrosEC.
      4 *
      5 * Copyright (C) 2017 Google, Inc
      6 */
      7
      8#include <linux/device.h>
      9#include <linux/iio/buffer.h>
     10#include <linux/iio/common/cros_ec_sensors_core.h>
     11#include <linux/iio/iio.h>
     12#include <linux/iio/kfifo_buf.h>
     13#include <linux/iio/trigger.h>
     14#include <linux/iio/triggered_buffer.h>
     15#include <linux/iio/trigger_consumer.h>
     16#include <linux/kernel.h>
     17#include <linux/module.h>
     18#include <linux/slab.h>
     19#include <linux/platform_data/cros_ec_commands.h>
     20#include <linux/platform_data/cros_ec_proto.h>
     21#include <linux/platform_device.h>
     22
     23/*
     24 * One channel for pressure, the other for timestamp.
     25 */
     26#define CROS_EC_BARO_MAX_CHANNELS (1 + 1)
     27
     28/* State data for ec_sensors iio driver. */
     29struct cros_ec_baro_state {
     30	/* Shared by all sensors */
     31	struct cros_ec_sensors_core_state core;
     32
     33	struct iio_chan_spec channels[CROS_EC_BARO_MAX_CHANNELS];
     34};
     35
     36static int cros_ec_baro_read(struct iio_dev *indio_dev,
     37			     struct iio_chan_spec const *chan,
     38			     int *val, int *val2, long mask)
     39{
     40	struct cros_ec_baro_state *st = iio_priv(indio_dev);
     41	u16 data = 0;
     42	int ret;
     43	int idx = chan->scan_index;
     44
     45	mutex_lock(&st->core.cmd_lock);
     46
     47	switch (mask) {
     48	case IIO_CHAN_INFO_RAW:
     49		ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
     50					     (s16 *)&data);
     51		if (ret)
     52			break;
     53
     54		*val = data;
     55		ret = IIO_VAL_INT;
     56		break;
     57	case IIO_CHAN_INFO_SCALE:
     58		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
     59		st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
     60
     61		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
     62		if (ret)
     63			break;
     64
     65		*val = st->core.resp->sensor_range.ret;
     66
     67		/* scale * in_pressure_raw --> kPa */
     68		*val2 = 10 << CROS_EC_SENSOR_BITS;
     69		ret = IIO_VAL_FRACTIONAL;
     70		break;
     71	default:
     72		ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
     73						mask);
     74		break;
     75	}
     76
     77	mutex_unlock(&st->core.cmd_lock);
     78
     79	return ret;
     80}
     81
     82static int cros_ec_baro_write(struct iio_dev *indio_dev,
     83			      struct iio_chan_spec const *chan,
     84			      int val, int val2, long mask)
     85{
     86	struct cros_ec_baro_state *st = iio_priv(indio_dev);
     87	int ret = 0;
     88
     89	mutex_lock(&st->core.cmd_lock);
     90
     91	switch (mask) {
     92	case IIO_CHAN_INFO_SCALE:
     93		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
     94		st->core.param.sensor_range.data = val;
     95
     96		/* Always roundup, so caller gets at least what it asks for. */
     97		st->core.param.sensor_range.roundup = 1;
     98
     99		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
    100		if (ret == 0) {
    101			st->core.range_updated = true;
    102			st->core.curr_range = val;
    103		}
    104		break;
    105	default:
    106		ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
    107						 mask);
    108		break;
    109	}
    110
    111	mutex_unlock(&st->core.cmd_lock);
    112
    113	return ret;
    114}
    115
    116static const struct iio_info cros_ec_baro_info = {
    117	.read_raw = &cros_ec_baro_read,
    118	.write_raw = &cros_ec_baro_write,
    119	.read_avail = &cros_ec_sensors_core_read_avail,
    120};
    121
    122static int cros_ec_baro_probe(struct platform_device *pdev)
    123{
    124	struct device *dev = &pdev->dev;
    125	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
    126	struct iio_dev *indio_dev;
    127	struct cros_ec_baro_state *state;
    128	struct iio_chan_spec *channel;
    129	int ret;
    130
    131	if (!ec_dev || !ec_dev->ec_dev) {
    132		dev_warn(dev, "No CROS EC device found.\n");
    133		return -EINVAL;
    134	}
    135
    136	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
    137	if (!indio_dev)
    138		return -ENOMEM;
    139
    140	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
    141					cros_ec_sensors_capture,
    142					cros_ec_sensors_push_data);
    143	if (ret)
    144		return ret;
    145
    146	indio_dev->info = &cros_ec_baro_info;
    147	state = iio_priv(indio_dev);
    148	state->core.type = state->core.resp->info.type;
    149	state->core.loc = state->core.resp->info.location;
    150	channel = state->channels;
    151	/* Common part */
    152	channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
    153	channel->info_mask_shared_by_all =
    154		BIT(IIO_CHAN_INFO_SCALE) |
    155		BIT(IIO_CHAN_INFO_SAMP_FREQ);
    156	channel->info_mask_shared_by_all_available =
    157		BIT(IIO_CHAN_INFO_SAMP_FREQ);
    158	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
    159	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
    160	channel->scan_type.shift = 0;
    161	channel->scan_index = 0;
    162	channel->ext_info = cros_ec_sensors_ext_info;
    163	channel->scan_type.sign = 'u';
    164
    165	/* Sensor specific */
    166	switch (state->core.type) {
    167	case MOTIONSENSE_TYPE_BARO:
    168		channel->type = IIO_PRESSURE;
    169		break;
    170	default:
    171		dev_warn(dev, "Unknown motion sensor\n");
    172		return -EINVAL;
    173	}
    174
    175	/* Timestamp */
    176	channel++;
    177	channel->type = IIO_TIMESTAMP;
    178	channel->channel = -1;
    179	channel->scan_index = 1;
    180	channel->scan_type.sign = 's';
    181	channel->scan_type.realbits = 64;
    182	channel->scan_type.storagebits = 64;
    183
    184	indio_dev->channels = state->channels;
    185	indio_dev->num_channels = CROS_EC_BARO_MAX_CHANNELS;
    186
    187	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
    188
    189	return devm_iio_device_register(dev, indio_dev);
    190}
    191
    192static const struct platform_device_id cros_ec_baro_ids[] = {
    193	{
    194		.name = "cros-ec-baro",
    195	},
    196	{ /* sentinel */ }
    197};
    198MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids);
    199
    200static struct platform_driver cros_ec_baro_platform_driver = {
    201	.driver = {
    202		.name	= "cros-ec-baro",
    203		.pm	= &cros_ec_sensors_pm_ops,
    204	},
    205	.probe		= cros_ec_baro_probe,
    206	.id_table	= cros_ec_baro_ids,
    207};
    208module_platform_driver(cros_ec_baro_platform_driver);
    209
    210MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver");
    211MODULE_LICENSE("GPL v2");