aboutsummaryrefslogtreecommitdiff
path: root/drivers/iio/pressure/cros_ec_baro.c
blob: d3acba7ba58262a200b04f36d46c290b7e8a18f3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
// SPDX-License-Identifier: GPL-2.0
/*
 * cros_ec_baro - Driver for barometer sensor behind CrosEC.
 *
 * Copyright (C) 2017 Google, Inc
 */

#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/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>

/*
 * One channel for pressure, the other for timestamp.
 */
#define CROS_EC_BARO_MAX_CHANNELS (1 + 1)

/* State data for ec_sensors iio driver. */
struct cros_ec_baro_state {
	/* Shared by all sensors */
	struct cros_ec_sensors_core_state core;

	struct iio_chan_spec channels[CROS_EC_BARO_MAX_CHANNELS];
};

static int cros_ec_baro_read(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int *val, int *val2, long mask)
{
	struct cros_ec_baro_state *st = iio_priv(indio_dev);
	u16 data = 0;
	int ret = IIO_VAL_INT;
	int idx = chan->scan_index;

	mutex_lock(&st->core.cmd_lock);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
					     (s16 *)&data) < 0)
			ret = -EIO;
		*val = data;
		break;
	case IIO_CHAN_INFO_SCALE:
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
		st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;

		if (cros_ec_motion_send_host_cmd(&st->core, 0)) {
			ret = -EIO;
			break;
		}
		*val = st->core.resp->sensor_range.ret;

		/* scale * in_pressure_raw --> kPa */
		*val2 = 10 << CROS_EC_SENSOR_BITS;
		ret = IIO_VAL_FRACTIONAL;
		break;
	default:
		ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
						mask);
		break;
	}

	mutex_unlock(&st->core.cmd_lock);

	return ret;
}

static int cros_ec_baro_write(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      int val, int val2, long mask)
{
	struct cros_ec_baro_state *st = iio_priv(indio_dev);
	int ret = 0;

	mutex_lock(&st->core.cmd_lock);

	switch (mask) {
	case IIO_CHAN_INFO_SCALE:
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
		st->core.param.sensor_range.data = val;

		/* Always roundup, so caller gets at least what it asks for. */
		st->core.param.sensor_range.roundup = 1;

		if (cros_ec_motion_send_host_cmd(&st->core, 0))
			ret = -EIO;
		break;
	default:
		ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
						 mask);
		break;
	}

	mutex_unlock(&st->core.cmd_lock);

	return ret;
}

static const struct iio_info cros_ec_baro_info = {
	.read_raw = &cros_ec_baro_read,
	.write_raw = &cros_ec_baro_write,
};

static int cros_ec_baro_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
	struct iio_dev *indio_dev;
	struct cros_ec_baro_state *state;
	struct iio_chan_spec *channel;
	int ret;

	if (!ec_dev || !ec_dev->ec_dev) {
		dev_warn(dev, "No CROS EC device found.\n");
		return -EINVAL;
	}

	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
	if (!indio_dev)
		return -ENOMEM;

	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
	if (ret)
		return ret;

	indio_dev->info = &cros_ec_baro_info;
	state = iio_priv(indio_dev);
	state->core.type = state->core.resp->info.type;
	state->core.loc = state->core.resp->info.location;
	channel = state->channels;
	/* Common part */
	channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
	channel->info_mask_shared_by_all =
		BIT(IIO_CHAN_INFO_SCALE) |
		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
		BIT(IIO_CHAN_INFO_FREQUENCY);
	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
	channel->scan_type.shift = 0;
	channel->scan_index = 0;
	channel->ext_info = cros_ec_sensors_ext_info;
	channel->scan_type.sign = 'u';

	/* Sensor specific */
	switch (state->core.type) {
	case MOTIONSENSE_TYPE_BARO:
		channel->type = IIO_PRESSURE;
		break;
	default:
		dev_warn(dev, "Unknown motion sensor\n");
		return -EINVAL;
	}

	/* Timestamp */
	channel++;
	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 = CROS_EC_BARO_MAX_CHANNELS;

	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;

	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
					      cros_ec_sensors_capture, NULL);
	if (ret)
		return ret;

	return devm_iio_device_register(dev, indio_dev);
}

static const struct platform_device_id cros_ec_baro_ids[] = {
	{
		.name = "cros-ec-baro",
	},
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids);

static struct platform_driver cros_ec_baro_platform_driver = {
	.driver = {
		.name	= "cros-ec-baro",
	},
	.probe		= cros_ec_baro_probe,
	.id_table	= cros_ec_baro_ids,
};
module_platform_driver(cros_ec_baro_platform_driver);

MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver");
MODULE_LICENSE("GPL v2");