1 // SPDX-License-Identifier: GPL-2.0
3 * cros_ec_baro - Driver for barometer sensor behind CrosEC.
5 * Copyright (C) 2017 Google, Inc
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/mfd/cros_ec.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/platform_data/cros_ec_commands.h>
21 #include <linux/platform_data/cros_ec_proto.h>
22 #include <linux/platform_device.h>
25 * One channel for pressure, the other for timestamp.
27 #define CROS_EC_BARO_MAX_CHANNELS (1 + 1)
29 /* State data for ec_sensors iio driver. */
30 struct cros_ec_baro_state {
31 /* Shared by all sensors */
32 struct cros_ec_sensors_core_state core;
34 struct iio_chan_spec channels[CROS_EC_BARO_MAX_CHANNELS];
37 static int cros_ec_baro_read(struct iio_dev *indio_dev,
38 struct iio_chan_spec const *chan,
39 int *val, int *val2, long mask)
41 struct cros_ec_baro_state *st = iio_priv(indio_dev);
44 int idx = chan->scan_index;
46 mutex_lock(&st->core.cmd_lock);
49 case IIO_CHAN_INFO_RAW:
50 ret = cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
58 case IIO_CHAN_INFO_SCALE:
59 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
60 st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
62 ret = cros_ec_motion_send_host_cmd(&st->core, 0);
66 *val = st->core.resp->sensor_range.ret;
68 /* scale * in_pressure_raw --> kPa */
69 *val2 = 10 << CROS_EC_SENSOR_BITS;
70 ret = IIO_VAL_FRACTIONAL;
73 ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
78 mutex_unlock(&st->core.cmd_lock);
83 static int cros_ec_baro_write(struct iio_dev *indio_dev,
84 struct iio_chan_spec const *chan,
85 int val, int val2, long mask)
87 struct cros_ec_baro_state *st = iio_priv(indio_dev);
90 mutex_lock(&st->core.cmd_lock);
93 case IIO_CHAN_INFO_SCALE:
94 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
95 st->core.param.sensor_range.data = val;
97 /* Always roundup, so caller gets at least what it asks for. */
98 st->core.param.sensor_range.roundup = 1;
100 if (cros_ec_motion_send_host_cmd(&st->core, 0))
104 ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
109 mutex_unlock(&st->core.cmd_lock);
114 static const struct iio_info cros_ec_baro_info = {
115 .read_raw = &cros_ec_baro_read,
116 .write_raw = &cros_ec_baro_write,
119 static int cros_ec_baro_probe(struct platform_device *pdev)
121 struct device *dev = &pdev->dev;
122 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
123 struct iio_dev *indio_dev;
124 struct cros_ec_baro_state *state;
125 struct iio_chan_spec *channel;
128 if (!ec_dev || !ec_dev->ec_dev) {
129 dev_warn(dev, "No CROS EC device found.\n");
133 indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
137 ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
141 indio_dev->info = &cros_ec_baro_info;
142 state = iio_priv(indio_dev);
143 state->core.type = state->core.resp->info.type;
144 state->core.loc = state->core.resp->info.location;
145 channel = state->channels;
147 channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
148 channel->info_mask_shared_by_all =
149 BIT(IIO_CHAN_INFO_SCALE) |
150 BIT(IIO_CHAN_INFO_SAMP_FREQ) |
151 BIT(IIO_CHAN_INFO_FREQUENCY);
152 channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
153 channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
154 channel->scan_type.shift = 0;
155 channel->scan_index = 0;
156 channel->ext_info = cros_ec_sensors_ext_info;
157 channel->scan_type.sign = 'u';
159 /* Sensor specific */
160 switch (state->core.type) {
161 case MOTIONSENSE_TYPE_BARO:
162 channel->type = IIO_PRESSURE;
165 dev_warn(dev, "Unknown motion sensor\n");
171 channel->type = IIO_TIMESTAMP;
172 channel->channel = -1;
173 channel->scan_index = 1;
174 channel->scan_type.sign = 's';
175 channel->scan_type.realbits = 64;
176 channel->scan_type.storagebits = 64;
178 indio_dev->channels = state->channels;
179 indio_dev->num_channels = CROS_EC_BARO_MAX_CHANNELS;
181 state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
183 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
184 cros_ec_sensors_capture, NULL);
188 return devm_iio_device_register(dev, indio_dev);
191 static const struct platform_device_id cros_ec_baro_ids[] = {
193 .name = "cros-ec-baro",
197 MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids);
199 static struct platform_driver cros_ec_baro_platform_driver = {
201 .name = "cros-ec-baro",
203 .probe = cros_ec_baro_probe,
204 .id_table = cros_ec_baro_ids,
206 module_platform_driver(cros_ec_baro_platform_driver);
208 MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver");
209 MODULE_LICENSE("GPL v2");