diff options
Diffstat (limited to 'drivers/iio/accel/cros_ec_accel_legacy.c')
| -rw-r--r-- | drivers/iio/accel/cros_ec_accel_legacy.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c new file mode 100644 index 000000000..0f403342b --- /dev/null +++ b/drivers/iio/accel/cros_ec_accel_legacy.c @@ -0,0 +1,252 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for older Chrome OS EC accelerometer + * + * Copyright 2017 Google, Inc + * + * This driver uses the memory mapper cros-ec interface to communicate + * with the Chrome OS EC about accelerometer data or older commands. + * Accelerometer access is presented through iio sysfs. + */ + +#include <linux/delay.h> +#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/module.h> +#include <linux/slab.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/platform_device.h> + +#define DRV_NAME "cros-ec-accel-legacy" + +#define CROS_EC_SENSOR_LEGACY_NUM 2 +/* + * Sensor scale hard coded at 10 bits per g, computed as: + * g / (2^10 - 1) = 0.009586168; with g = 9.80665 m.s^-2 + */ +#define ACCEL_LEGACY_NSCALE 9586168 + +/* + * Sensor frequency is hard-coded to 10Hz. + */ +static const int cros_ec_legacy_sample_freq[] = { 10, 0 }; + +static int cros_ec_accel_legacy_read_cmd(struct iio_dev *indio_dev, + unsigned long scan_mask, s16 *data) +{ + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev); + int ret; + unsigned int i; + u8 sensor_num; + + /* + * Read all sensor data through a command. + * Save sensor_num, it is assumed to stay. + */ + sensor_num = st->param.info.sensor_num; + st->param.cmd = MOTIONSENSE_CMD_DUMP; + st->param.dump.max_sensor_count = CROS_EC_SENSOR_LEGACY_NUM; + ret = cros_ec_motion_send_host_cmd(st, + sizeof(st->resp->dump) + CROS_EC_SENSOR_LEGACY_NUM * + sizeof(struct ec_response_motion_sensor_data)); + st->param.info.sensor_num = sensor_num; + if (ret != 0) { + dev_warn(&indio_dev->dev, "Unable to read sensor data\n"); + return ret; + } + + for_each_set_bit(i, &scan_mask, indio_dev->masklength) { + *data = st->resp->dump.sensor[sensor_num].data[i] * + st->sign[i]; + data++; + } + + return 0; +} + +static int cros_ec_accel_legacy_read(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev); + s16 data = 0; + int ret; + int idx = chan->scan_index; + + mutex_lock(&st->cmd_lock); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = st->read_ec_sensors_data(indio_dev, 1 << idx, &data); + if (ret < 0) + break; + ret = IIO_VAL_INT; + *val = data; + break; + case IIO_CHAN_INFO_SCALE: + WARN_ON(st->type != MOTIONSENSE_TYPE_ACCEL); + *val = 0; + *val2 = ACCEL_LEGACY_NSCALE; + ret = IIO_VAL_INT_PLUS_NANO; + break; + case IIO_CHAN_INFO_CALIBBIAS: + /* Calibration not supported. */ + *val = 0; + ret = IIO_VAL_INT; + break; + case IIO_CHAN_INFO_SAMP_FREQ: + *val = cros_ec_legacy_sample_freq[0]; + *val2 = cros_ec_legacy_sample_freq[1]; + ret = IIO_VAL_INT_PLUS_MICRO; + break; + default: + ret = cros_ec_sensors_core_read(st, chan, val, val2, + mask); + break; + } + mutex_unlock(&st->cmd_lock); + + return ret; +} + +static int cros_ec_accel_legacy_write(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + /* + * Do nothing but don't return an error code to allow calibration + * script to work. + */ + if (mask == IIO_CHAN_INFO_CALIBBIAS) + return 0; + + return -EINVAL; +} + +/** + * cros_ec_accel_legacy_read_avail() - get available values + * @indio_dev: pointer to state information for device + * @chan: channel specification structure table + * @vals: list of available values + * @type: type of data returned + * @length: number of data returned in the array + * @mask: specifies which values to be requested + * + * Return: an error code or IIO_AVAIL_LIST + */ +static int cros_ec_accel_legacy_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, + int *type, + int *length, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_SAMP_FREQ: + *length = ARRAY_SIZE(cros_ec_legacy_sample_freq); + *vals = cros_ec_legacy_sample_freq; + *type = IIO_VAL_INT_PLUS_MICRO; + return IIO_AVAIL_LIST; + } + + return -EINVAL; +} + +static const struct iio_info cros_ec_accel_legacy_info = { + .read_raw = &cros_ec_accel_legacy_read, + .write_raw = &cros_ec_accel_legacy_write, + .read_avail = &cros_ec_accel_legacy_read_avail, +}; + +/* + * Present the channel using HTML5 standard: + * need to invert X and Y and invert some lid axis. + */ +#define CROS_EC_ACCEL_ROTATE_AXIS(_axis) \ + ((_axis) == CROS_EC_SENSOR_Z ? CROS_EC_SENSOR_Z : \ + ((_axis) == CROS_EC_SENSOR_X ? CROS_EC_SENSOR_Y : \ + CROS_EC_SENSOR_X)) + +#define CROS_EC_ACCEL_LEGACY_CHAN(_axis) \ + { \ + .type = IIO_ACCEL, \ + .channel2 = IIO_MOD_X + (_axis), \ + .modified = 1, \ + .info_mask_separate = \ + BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_CALIBBIAS), \ + .info_mask_shared_by_all = \ + BIT(IIO_CHAN_INFO_SCALE) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .info_mask_shared_by_all_available = \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .ext_info = cros_ec_sensors_ext_info, \ + .scan_type = { \ + .sign = 's', \ + .realbits = CROS_EC_SENSOR_BITS, \ + .storagebits = CROS_EC_SENSOR_BITS, \ + }, \ + .scan_index = CROS_EC_ACCEL_ROTATE_AXIS(_axis), \ + } \ + +static const struct iio_chan_spec cros_ec_accel_legacy_channels[] = { + CROS_EC_ACCEL_LEGACY_CHAN(CROS_EC_SENSOR_X), + CROS_EC_ACCEL_LEGACY_CHAN(CROS_EC_SENSOR_Y), + CROS_EC_ACCEL_LEGACY_CHAN(CROS_EC_SENSOR_Z), + IIO_CHAN_SOFT_TIMESTAMP(CROS_EC_SENSOR_MAX_AXIS) +}; + +static int cros_ec_accel_legacy_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct iio_dev *indio_dev; + struct cros_ec_sensors_core_state *state; + int ret; + + 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 = &cros_ec_accel_legacy_info; + state = iio_priv(indio_dev); + + if (state->ec->cmd_readmem != NULL) + state->read_ec_sensors_data = cros_ec_sensors_read_lpc; + else + state->read_ec_sensors_data = cros_ec_accel_legacy_read_cmd; + + indio_dev->channels = cros_ec_accel_legacy_channels; + indio_dev->num_channels = ARRAY_SIZE(cros_ec_accel_legacy_channels); + /* The lid sensor needs to be presented inverted. */ + if (!strcmp(indio_dev->label, "accel-display")) { + state->sign[CROS_EC_SENSOR_X] = -1; + state->sign[CROS_EC_SENSOR_Z] = -1; + } + + return cros_ec_sensors_core_register(dev, indio_dev, NULL); +} + +static struct platform_driver cros_ec_accel_platform_driver = { + .driver = { + .name = DRV_NAME, + }, + .probe = cros_ec_accel_legacy_probe, +}; +module_platform_driver(cros_ec_accel_platform_driver); + +MODULE_DESCRIPTION("ChromeOS EC legacy accelerometer driver"); +MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRV_NAME); |