diff options
Diffstat (limited to 'drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c')
-rw-r--r-- | drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c | 329 |
1 files changed, 329 insertions, 0 deletions
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 000000000..66153b185 --- /dev/null +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c @@ -0,0 +1,329 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * cros_ec_sensors - Driver for Chrome OS Embedded Controller sensors. + * + * Copyright (C) 2016 Google, Inc + * + * 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/device.h> +#include <linux/iio/buffer.h> +#include <linux/iio/common/cros_ec_sensors_core.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/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/platform_device.h> +#include <linux/slab.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; + 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; + ret = IIO_VAL_INT; + *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].offset = + st->core.resp->sensor_offset.offset[i]; + ret = IIO_VAL_INT; + *val = st->core.calib[idx].offset; + break; + case IIO_CHAN_INFO_CALIBSCALE: + st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_SCALE; + st->core.param.sensor_offset.flags = 0; + + ret = cros_ec_motion_send_host_cmd(&st->core, 0); + if (ret == -EPROTO || ret == -EOPNOTSUPP) { + /* Reading calibscale is not supported on older EC. */ + *val = 1; + *val2 = 0; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + } else if (ret) { + break; + } + + /* Save values */ + for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++) + st->core.calib[i].scale = + st->core.resp->sensor_scale.scale[i]; + + *val = st->core.calib[idx].scale >> 15; + *val2 = ((st->core.calib[idx].scale & 0x7FFF) * 1000000LL) / + MOTION_SENSE_DEFAULT_SCALE; + ret = IIO_VAL_INT_PLUS_MICRO; + 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 = 0; + *val2 = div_s64(val64 * 3141592653ULL, + 180 << (CROS_EC_SENSOR_BITS - 1)); + ret = IIO_VAL_INT_PLUS_NANO; + 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; + int idx = chan->scan_index; + + mutex_lock(&st->core.cmd_lock); + + switch (mask) { + case IIO_CHAN_INFO_CALIBBIAS: + st->core.calib[idx].offset = 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].offset; + 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_CALIBSCALE: + st->core.calib[idx].scale = val; + /* Send to EC for each axis, even if not complete */ + + st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_SCALE; + 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_scale.scale[i] = + st->core.calib[i].scale; + st->core.param.sensor_scale.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); + if (ret == 0) { + st->core.range_updated = true; + st->core.curr_range = val; + } + 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, + .read_avail = &cros_ec_sensors_core_read_avail, +}; + +static int cros_ec_sensors_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct iio_dev *indio_dev; + struct cros_ec_sensors_state *state; + struct iio_chan_spec *channel; + int ret, i; + + 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, + cros_ec_sensors_capture); + 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) | + BIT(IIO_CHAN_INFO_CALIBSCALE); + channel->info_mask_shared_by_all = + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_SAMP_FREQ); + channel->info_mask_shared_by_all_available = + 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; + + return cros_ec_sensors_core_register(dev, indio_dev, + cros_ec_sensors_push_data); +} + +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", + .pm = &cros_ec_sensors_pm_ops, + }, + .probe = cros_ec_sensors_probe, + .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"); |