diff options
author | Enric Balletbo i Serra <enric.balletbo@collabora.com> | 2016-08-01 11:54:36 +0200 |
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committer | Jonathan Cameron <jic23@kernel.org> | 2016-10-25 19:20:23 +0200 |
commit | c14dca07a31dac8bd91aa818df62fb3bf1d846c5 (patch) | |
tree | dd51984a0a2e8820b16e187d28fe4f6a4a7fd4e1 /drivers/iio | |
parent | iio: cros_ec_sensors_core: Add common functions for the ChromeOS EC Sensor Hub. (diff) | |
download | linux-c14dca07a31dac8bd91aa818df62fb3bf1d846c5.tar.xz linux-c14dca07a31dac8bd91aa818df62fb3bf1d846c5.zip |
iio: cros_ec_sensors: add ChromeOS EC Contiguous Sensors driver
Handle 3d contiguous sensors like Accelerometers, Gyroscope and
Magnetometer that are presented by the ChromeOS EC Sensor hub.
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio')
-rw-r--r-- | drivers/iio/common/cros_ec_sensors/Kconfig | 9 | ||||
-rw-r--r-- | drivers/iio/common/cros_ec_sensors/Makefile | 1 | ||||
-rw-r--r-- | drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c | 322 |
3 files changed, 332 insertions, 0 deletions
diff --git a/drivers/iio/common/cros_ec_sensors/Kconfig b/drivers/iio/common/cros_ec_sensors/Kconfig index 24743be15a5b..3349c9d2cf7a 100644 --- a/drivers/iio/common/cros_ec_sensors/Kconfig +++ b/drivers/iio/common/cros_ec_sensors/Kconfig @@ -12,3 +12,12 @@ config IIO_CROS_EC_SENSORS_CORE drivers. Define common attributes and sysfs interrupt handler. +config IIO_CROS_EC_SENSORS + tristate "ChromeOS EC Contiguous Sensors" + select IIO_CROS_EC_SENSORS_CORE + select MFD_CROSS_EC + help + Module to handle 3d contiguous sensors like + Accelerometers, Gyroscope and Magnetometer that are + presented by the ChromeOS EC Sensor hub. + Creates an IIO device for each functions. diff --git a/drivers/iio/common/cros_ec_sensors/Makefile b/drivers/iio/common/cros_ec_sensors/Makefile index 95b690139bfd..ec716ff2a775 100644 --- a/drivers/iio/common/cros_ec_sensors/Makefile +++ b/drivers/iio/common/cros_ec_sensors/Makefile @@ -3,3 +3,4 @@ # obj-$(CONFIG_IIO_CROS_EC_SENSORS_CORE) += cros_ec_sensors_core.o +obj-$(CONFIG_IIO_CROS_EC_SENSORS) += cros_ec_sensors.o diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c new file mode 100644 index 000000000000..48edeba35b83 --- /dev/null +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c @@ -0,0 +1,322 @@ +/* + * cros_ec_sensors - Driver for Chrome OS Embedded Controller sensors. + * + * Copyright (C) 2016 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. + * + * This driver uses the cros-ec interface to communicate with the Chrome OS + * EC about sensors data. Data access is presented through iio sysfs. + */ + +#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_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/kernel.h> +#include <linux/mfd/cros_ec.h> +#include <linux/mfd/cros_ec_commands.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/sysfs.h> + +#include "cros_ec_sensors_core.h" + +#define CROS_EC_SENSORS_MAX_CHANNELS 4 + +/* State data for ec_sensors iio driver. */ +struct cros_ec_sensors_state { + /* Shared by all sensors */ + struct cros_ec_sensors_core_state core; + + struct iio_chan_spec channels[CROS_EC_SENSORS_MAX_CHANNELS]; +}; + +static int cros_ec_sensors_read(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct cros_ec_sensors_state *st = iio_priv(indio_dev); + s16 data = 0; + s64 val64; + int i; + int ret = IIO_VAL_INT; + int idx = chan->scan_index; + + mutex_lock(&st->core.cmd_lock); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = st->core.read_ec_sensors_data(indio_dev, 1 << idx, &data); + if (ret < 0) + break; + + *val = data; + break; + case IIO_CHAN_INFO_CALIBBIAS: + st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET; + st->core.param.sensor_offset.flags = 0; + + ret = cros_ec_motion_send_host_cmd(&st->core, 0); + if (ret < 0) + break; + + /* Save values */ + for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++) + st->core.calib[i] = + st->core.resp->sensor_offset.offset[i]; + + *val = st->core.calib[idx]; + 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; + + ret = cros_ec_motion_send_host_cmd(&st->core, 0); + if (ret < 0) + break; + + val64 = st->core.resp->sensor_range.ret; + switch (st->core.type) { + case MOTIONSENSE_TYPE_ACCEL: + /* + * EC returns data in g, iio exepects m/s^2. + * Do not use IIO_G_TO_M_S_2 to avoid precision loss. + */ + *val = div_s64(val64 * 980665, 10); + *val2 = 10000 << (CROS_EC_SENSOR_BITS - 1); + ret = IIO_VAL_FRACTIONAL; + break; + case MOTIONSENSE_TYPE_GYRO: + /* + * EC returns data in dps, iio expects rad/s. + * Do not use IIO_DEGREE_TO_RAD to avoid precision + * loss. Round to the nearest integer. + */ + *val = div_s64(val64 * 314159 + 9000000ULL, 1000); + *val2 = 18000 << (CROS_EC_SENSOR_BITS - 1); + ret = IIO_VAL_FRACTIONAL; + break; + case MOTIONSENSE_TYPE_MAG: + /* + * EC returns data in 16LSB / uT, + * iio expects Gauss + */ + *val = val64; + *val2 = 100 << (CROS_EC_SENSOR_BITS - 1); + ret = IIO_VAL_FRACTIONAL; + break; + default: + ret = -EINVAL; + } + 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_sensors_write(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct cros_ec_sensors_state *st = iio_priv(indio_dev); + int i; + int ret = 0; + int idx = chan->scan_index; + + mutex_lock(&st->core.cmd_lock); + + switch (mask) { + case IIO_CHAN_INFO_CALIBBIAS: + st->core.calib[idx] = val; + + /* Send to EC for each axis, even if not complete */ + st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET; + st->core.param.sensor_offset.flags = + MOTION_SENSE_SET_OFFSET; + for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++) + st->core.param.sensor_offset.offset[i] = + st->core.calib[i]; + st->core.param.sensor_offset.temp = + EC_MOTION_SENSE_INVALID_CALIB_TEMP; + + ret = cros_ec_motion_send_host_cmd(&st->core, 0); + break; + case IIO_CHAN_INFO_SCALE: + if (st->core.type == MOTIONSENSE_TYPE_MAG) { + ret = -EINVAL; + break; + } + 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; + + ret = cros_ec_motion_send_host_cmd(&st->core, 0); + 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 ec_sensors_info = { + .read_raw = &cros_ec_sensors_read, + .write_raw = &cros_ec_sensors_write, + .driver_module = THIS_MODULE, +}; + +static int cros_ec_sensors_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_sensors_state *state; + struct iio_chan_spec *channel; + int ret, i; + + if (!ec_dev || !ec_dev->ec_dev) { + dev_warn(&pdev->dev, "No CROS EC device found.\n"); + return -EINVAL; + } + ec_device = ec_dev->ec_dev; + + indio_dev = devm_iio_device_alloc(&pdev->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 = &ec_sensors_info; + state = iio_priv(indio_dev); + for (channel = state->channels, i = CROS_EC_SENSOR_X; + i < CROS_EC_SENSOR_MAX_AXIS; i++, channel++) { + /* Common part */ + channel->info_mask_separate = + BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_CALIBBIAS); + channel->info_mask_shared_by_all = + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_FREQUENCY) | + BIT(IIO_CHAN_INFO_SAMP_FREQ); + channel->scan_type.realbits = CROS_EC_SENSOR_BITS; + channel->scan_type.storagebits = CROS_EC_SENSOR_BITS; + channel->scan_index = i; + channel->ext_info = cros_ec_sensors_ext_info; + channel->modified = 1; + channel->channel2 = IIO_MOD_X + i; + channel->scan_type.sign = 's'; + + /* Sensor specific */ + switch (state->core.type) { + case MOTIONSENSE_TYPE_ACCEL: + channel->type = IIO_ACCEL; + break; + case MOTIONSENSE_TYPE_GYRO: + channel->type = IIO_ANGL_VEL; + break; + case MOTIONSENSE_TYPE_MAG: + channel->type = IIO_MAGN; + break; + default: + dev_err(&pdev->dev, "Unknown motion sensor\n"); + return -EINVAL; + } + } + + /* Timestamp */ + channel->type = IIO_TIMESTAMP; + channel->channel = -1; + channel->scan_index = CROS_EC_SENSOR_MAX_AXIS; + 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_SENSORS_MAX_CHANNELS; + + /* There is only enough room for accel and gyro in the io space */ + if ((state->core.ec->cmd_readmem != NULL) && + (state->core.type != MOTIONSENSE_TYPE_MAG)) + state->core.read_ec_sensors_data = cros_ec_sensors_read_lpc; + else + state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd; + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + cros_ec_sensors_capture, NULL); + if (ret) + return ret; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_uninit_buffer; + + return 0; + +error_uninit_buffer: + iio_triggered_buffer_cleanup(indio_dev); + + return ret; +} + +static int cros_ec_sensors_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + + return 0; +} + +static const struct platform_device_id cros_ec_sensors_ids[] = { + { + .name = "cros-ec-accel", + }, + { + .name = "cros-ec-gyro", + }, + { + .name = "cros-ec-mag", + }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, cros_ec_sensors_ids); + +static struct platform_driver cros_ec_sensors_platform_driver = { + .driver = { + .name = "cros-ec-sensors", + }, + .probe = cros_ec_sensors_probe, + .remove = cros_ec_sensors_remove, + .id_table = cros_ec_sensors_ids, +}; +module_platform_driver(cros_ec_sensors_platform_driver); + +MODULE_DESCRIPTION("ChromeOS EC 3-axis sensors driver"); +MODULE_LICENSE("GPL v2"); |