// 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #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, iio_get_masklength(indio_dev)) { *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 "); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:" DRV_NAME);