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					true);
144	if (ret)
145		return ret;
146
147	indio_dev->info = &cros_ec_baro_info;
148	state = iio_priv(indio_dev);
149	state->core.type = state->core.resp->info.type;
150	state->core.loc = state->core.resp->info.location;
151	channel = state->channels;
152	/* Common part */
153	channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
154	channel->info_mask_shared_by_all =
155		BIT(IIO_CHAN_INFO_SCALE) |
156		BIT(IIO_CHAN_INFO_SAMP_FREQ);
157	channel->info_mask_shared_by_all_available =
158		BIT(IIO_CHAN_INFO_SAMP_FREQ);
159	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
160	channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
161	channel->scan_type.shift = 0;
162	channel->scan_index = 0;
163	channel->ext_info = cros_ec_sensors_ext_info;
164	channel->scan_type.sign = 'u';
165
166	/* Sensor specific */
167	switch (state->core.type) {
168	case MOTIONSENSE_TYPE_BARO:
169		channel->type = IIO_PRESSURE;
170		break;
171	default:
172		dev_warn(dev, "Unknown motion sensor\n");
173		return -EINVAL;
174	}
175
176	/* Timestamp */
177	channel++;
178	channel->type = IIO_TIMESTAMP;
179	channel->channel = -1;
180	channel->scan_index = 1;
181	channel->scan_type.sign = 's';
182	channel->scan_type.realbits = 64;
183	channel->scan_type.storagebits = 64;
184
185	indio_dev->channels = state->channels;
186	indio_dev->num_channels = CROS_EC_BARO_MAX_CHANNELS;
187
188	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
189
190	return devm_iio_device_register(dev, indio_dev);
191}
192
193static const struct platform_device_id cros_ec_baro_ids[] = {
194	{
195		.name = "cros-ec-baro",
196	},
197	{ /* sentinel */ }
198};
199MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids);
200
201static struct platform_driver cros_ec_baro_platform_driver = {
202	.driver = {
203		.name	= "cros-ec-baro",
204		.pm	= &cros_ec_sensors_pm_ops,
205	},
206	.probe		= cros_ec_baro_probe,
207	.id_table	= cros_ec_baro_ids,
208};
209module_platform_driver(cros_ec_baro_platform_driver);
210
211MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver");
212MODULE_LICENSE("GPL v2");
213