253 lines
6.9 KiB
C
253 lines
6.9 KiB
C
// 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);
|