2 * cros_ec_baro - Driver for barometer sensor behind CrosEC.
4 * Copyright (C) 2017 Google, Inc
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 #include <linux/delay.h>
17 #include <linux/device.h>
18 #include <linux/iio/buffer.h>
19 #include <linux/iio/iio.h>
20 #include <linux/iio/kfifo_buf.h>
21 #include <linux/iio/trigger.h>
22 #include <linux/iio/triggered_buffer.h>
23 #include <linux/iio/trigger_consumer.h>
24 #include <linux/kernel.h>
25 #include <linux/mfd/cros_ec.h>
26 #include <linux/mfd/cros_ec_commands.h>
27 #include <linux/module.h>
28 #include <linux/slab.h>
29 #include <linux/platform_device.h>
31 #include "../common/cros_ec_sensors/cros_ec_sensors_core.h"
34 * One channel for pressure, the other for timestamp.
36 #define CROS_EC_BARO_MAX_CHANNELS (1 + 1)
38 /* State data for ec_sensors iio driver. */
39 struct cros_ec_baro_state {
40 /* Shared by all sensors */
41 struct cros_ec_sensors_core_state core;
43 struct iio_chan_spec channels[CROS_EC_BARO_MAX_CHANNELS];
46 static int cros_ec_baro_read(struct iio_dev *indio_dev,
47 struct iio_chan_spec const *chan,
48 int *val, int *val2, long mask)
50 struct cros_ec_baro_state *st = iio_priv(indio_dev);
52 int ret = IIO_VAL_INT;
53 int idx = chan->scan_index;
55 mutex_lock(&st->core.cmd_lock);
58 case IIO_CHAN_INFO_RAW:
59 if (cros_ec_sensors_read_cmd(indio_dev, 1 << idx,
64 case IIO_CHAN_INFO_SCALE:
65 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
66 st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
68 if (cros_ec_motion_send_host_cmd(&st->core, 0)) {
72 *val = st->core.resp->sensor_range.ret;
74 /* scale * in_pressure_raw --> kPa */
75 *val2 = 10 << CROS_EC_SENSOR_BITS;
76 ret = IIO_VAL_FRACTIONAL;
79 ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
84 mutex_unlock(&st->core.cmd_lock);
89 static int cros_ec_baro_write(struct iio_dev *indio_dev,
90 struct iio_chan_spec const *chan,
91 int val, int val2, long mask)
93 struct cros_ec_baro_state *st = iio_priv(indio_dev);
96 mutex_lock(&st->core.cmd_lock);
99 case IIO_CHAN_INFO_SCALE:
100 st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
101 st->core.param.sensor_range.data = val;
103 /* Always roundup, so caller gets at least what it asks for. */
104 st->core.param.sensor_range.roundup = 1;
106 if (cros_ec_motion_send_host_cmd(&st->core, 0))
110 ret = cros_ec_sensors_core_write(&st->core, chan, val, val2,
115 mutex_unlock(&st->core.cmd_lock);
120 static const struct iio_info cros_ec_baro_info = {
121 .read_raw = &cros_ec_baro_read,
122 .write_raw = &cros_ec_baro_write,
123 .driver_module = THIS_MODULE,
126 static int cros_ec_baro_probe(struct platform_device *pdev)
128 struct device *dev = &pdev->dev;
129 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
130 struct cros_ec_device *ec_device;
131 struct iio_dev *indio_dev;
132 struct cros_ec_baro_state *state;
133 struct iio_chan_spec *channel;
136 if (!ec_dev || !ec_dev->ec_dev) {
137 dev_warn(dev, "No CROS EC device found.\n");
140 ec_device = ec_dev->ec_dev;
142 indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
146 ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
150 indio_dev->info = &cros_ec_baro_info;
151 state = iio_priv(indio_dev);
152 state->core.type = state->core.resp->info.type;
153 state->core.loc = state->core.resp->info.location;
154 channel = state->channels;
156 channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
157 channel->info_mask_shared_by_all =
158 BIT(IIO_CHAN_INFO_SCALE) |
159 BIT(IIO_CHAN_INFO_SAMP_FREQ) |
160 BIT(IIO_CHAN_INFO_FREQUENCY);
161 channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
162 channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
163 channel->scan_type.shift = 0;
164 channel->scan_index = 0;
165 channel->ext_info = cros_ec_sensors_ext_info;
166 channel->scan_type.sign = 'u';
168 state->core.calib[0] = 0;
170 /* Sensor specific */
171 switch (state->core.type) {
172 case MOTIONSENSE_TYPE_BARO:
173 channel->type = IIO_PRESSURE;
176 dev_warn(dev, "Unknown motion sensor\n");
182 channel->type = IIO_TIMESTAMP;
183 channel->channel = -1;
184 channel->scan_index = 1;
185 channel->scan_type.sign = 's';
186 channel->scan_type.realbits = 64;
187 channel->scan_type.storagebits = 64;
189 indio_dev->channels = state->channels;
190 indio_dev->num_channels = CROS_EC_BARO_MAX_CHANNELS;
192 state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
194 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
195 cros_ec_sensors_capture, NULL);
199 return devm_iio_device_register(dev, indio_dev);
202 static const struct platform_device_id cros_ec_baro_ids[] = {
204 .name = "cros-ec-baro",
208 MODULE_DEVICE_TABLE(platform, cros_ec_baro_ids);
210 static struct platform_driver cros_ec_baro_platform_driver = {
212 .name = "cros-ec-baro",
214 .probe = cros_ec_baro_probe,
215 .id_table = cros_ec_baro_ids,
217 module_platform_driver(cros_ec_baro_platform_driver);
219 MODULE_DESCRIPTION("ChromeOS EC barometer sensor driver");
220 MODULE_LICENSE("GPL v2");