| /* |
| * 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; |
| 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; |
| 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"); |