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/mod_devicetable.h>
 24#include <linux/module.h>
 25#include <linux/platform_data/cros_ec_commands.h>
 26#include <linux/platform_device.h>
 27#include <linux/slab.h>
 28
 29#define DRV_NAME "cros-ec-lid-angle"
 30
 31/*
 32 * One channel for the lid angle, the other for timestamp.
 33 */
 34static const struct iio_chan_spec cros_ec_lid_angle_channels[] = {
 35	{
 36		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 37		.scan_type.realbits = CROS_EC_SENSOR_BITS,
 38		.scan_type.storagebits = CROS_EC_SENSOR_BITS,
 39		.scan_type.sign = 'u',
 40		.type = IIO_ANGL
 41	},
 42	IIO_CHAN_SOFT_TIMESTAMP(1)
 43};
 44
 45/* State data for ec_sensors iio driver. */
 46struct cros_ec_lid_angle_state {
 47	/* Shared by all sensors */
 48	struct cros_ec_sensors_core_state core;
 49};
 50
 51static int cros_ec_sensors_read_lid_angle(struct iio_dev *indio_dev,
 52					  unsigned long scan_mask, s16 *data)
 53{
 54	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
 55	int ret;
 56
 57	st->param.cmd = MOTIONSENSE_CMD_LID_ANGLE;
 58	ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->lid_angle));
 59	if (ret) {
 60		dev_warn(&indio_dev->dev, "Unable to read lid angle\n");
 61		return ret;
 62	}
 63
 64	*data = st->resp->lid_angle.value;
 65	return 0;
 66}
 67
 68static int cros_ec_lid_angle_read(struct iio_dev *indio_dev,
 69				    struct iio_chan_spec const *chan,
 70				    int *val, int *val2, long mask)
 71{
 72	struct cros_ec_lid_angle_state *st = iio_priv(indio_dev);
 73	s16 data;
 74	int ret;
 75
 76	mutex_lock(&st->core.cmd_lock);
 77	ret = cros_ec_sensors_read_lid_angle(indio_dev, 1, &data);
 78	if (ret == 0) {
 79		*val = data;
 80		ret = IIO_VAL_INT;
 81	}
 82	mutex_unlock(&st->core.cmd_lock);
 83	return ret;
 84}
 85
 86static const struct iio_info cros_ec_lid_angle_info = {
 87	.read_raw = &cros_ec_lid_angle_read,
 88};
 89
 90static int cros_ec_lid_angle_probe(struct platform_device *pdev)
 91{
 92	struct device *dev = &pdev->dev;
 93	struct iio_dev *indio_dev;
 94	struct cros_ec_lid_angle_state *state;
 95	int ret;
 96
 97	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
 98	if (!indio_dev)
 99		return -ENOMEM;
100
101	ret = cros_ec_sensors_core_init(pdev, indio_dev, false, NULL);
102	if (ret)
103		return ret;
104
105	indio_dev->info = &cros_ec_lid_angle_info;
106	state = iio_priv(indio_dev);
107	indio_dev->channels = cros_ec_lid_angle_channels;
108	indio_dev->num_channels = ARRAY_SIZE(cros_ec_lid_angle_channels);
109
110	state->core.read_ec_sensors_data = cros_ec_sensors_read_lid_angle;
111
112	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
113			cros_ec_sensors_capture, NULL);
114	if (ret)
115		return ret;
116
117	return cros_ec_sensors_core_register(dev, indio_dev, NULL);
118}
119
120static const struct platform_device_id cros_ec_lid_angle_ids[] = {
121	{
122		.name = DRV_NAME,
123	},
124	{ /* sentinel */ }
125};
126MODULE_DEVICE_TABLE(platform, cros_ec_lid_angle_ids);
127
128static struct platform_driver cros_ec_lid_angle_platform_driver = {
129	.driver = {
130		.name	= DRV_NAME,
131	},
132	.probe		= cros_ec_lid_angle_probe,
133	.id_table	= cros_ec_lid_angle_ids,
134};
135module_platform_driver(cros_ec_lid_angle_platform_driver);
136
137MODULE_DESCRIPTION("ChromeOS EC driver for reporting convertible lid angle.");
138MODULE_LICENSE("GPL v2");