diff options
Diffstat (limited to 'drivers/iio/pressure/cros_ec_baro.c')
| -rw-r--r-- | drivers/iio/pressure/cros_ec_baro.c | 220 |
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"); |