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path: root/drivers/iio/pressure/cros_ec_baro.c
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Diffstat (limited to 'drivers/iio/pressure/cros_ec_baro.c')
-rw-r--r--drivers/iio/pressure/cros_ec_baro.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/iio/pressure/cros_ec_baro.c b/drivers/iio/pressure/cros_ec_baro.c
new file mode 100644
index 000000000000..48b2a30f57ae
--- /dev/null
+++ b/drivers/iio/pressure/cros_ec_baro.c
@@ -0,0 +1,220 @@
+/*
+ * cros_ec_baro - Driver for barometer sensor behind CrosEC.
+ *
+ * Copyright (C) 2017 Google, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/iio/buffer.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>
+
+#include "../common/cros_ec_sensors/cros_ec_sensors_core.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,
+ .driver_module = THIS_MODULE,
+};
+
+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 cros_ec_device *ec_device;
+ 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;
+ }
+ ec_device = ec_dev->ec_dev;
+
+ 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';
+
+ state->core.calib[0] = 0;
+
+ /* 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");