/****************************************************************************
* drivers/sensors/sensor.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <poll.h>
#include <fcntl.h>
#include <nuttx/kmalloc.h>
#include <nuttx/mm/circbuf.h>
#include <nuttx/sensors/sensor.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Device naming ************************************************************/
#define ROUNDUP(x, esize) ((x + (esize - 1)) / (esize)) * (esize)
#define DEVNAME_FMT "/dev/sensor/%s%s%d"
#define DEVNAME_MAX 64
#define DEVNAME_UNCAL "_uncal"
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure describes sensor info */
struct sensor_info
{
uint8_t esize;
FAR char *name;
};
/* This structure describes the state of the upper half driver */
struct sensor_upperhalf_s
{
/* poll structures of threads waiting for driver events. */
FAR struct pollfd *fds[CONFIG_SENSORS_NPOLLWAITERS];
FAR struct sensor_lowerhalf_s *lower; /* the handle of lower half driver */
struct circbuf_s buffer; /* The circular buffer of sensor device */
uint8_t esize; /* The element size of circular buffer */
uint8_t crefs; /* Number of times the device has been opened */
sem_t exclsem; /* Manages exclusive access to file operations */
sem_t buffersem; /* Wakeup user waiting for data in circular buffer */
bool enabled; /* The status of sensor enable or disable */
unsigned int interval; /* The sample interval for sensor, in us */
unsigned int latency; /* The batch latency for sensor, in us */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void sensor_pollnotify(FAR struct sensor_upperhalf_s *upper,
pollevent_t eventset);
static int sensor_open(FAR struct file *filep);
static int sensor_close(FAR struct file *filep);
static ssize_t sensor_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static int sensor_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
static int sensor_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct sensor_info g_sensor_info[] =
{
{0, NULL},
{sizeof(struct sensor_event_accel), "accel"},
{sizeof(struct sensor_event_mag), "mag"},
{sizeof(struct sensor_event_gyro), "gyro"},
{sizeof(struct sensor_event_light), "light"},
{sizeof(struct sensor_event_baro), "baro"},
{sizeof(struct sensor_event_prox), "prox"},
{sizeof(struct sensor_event_humi), "humi"},
{sizeof(struct sensor_event_temp), "temp"},
{sizeof(struct sensor_event_rgb), "rgb"},
{sizeof(struct sensor_event_hall), "hall"},
{sizeof(struct sensor_event_ir), "ir"},
{sizeof(struct sensor_event_gps), "gps"},
{sizeof(struct sensor_event_uv), "uv"},
{sizeof(struct sensor_event_noise), "noise"},
{sizeof(struct sensor_event_pm25), "pm25"},
{sizeof(struct sensor_event_pm1p0), "pm1p0"},
{sizeof(struct sensor_event_pm10), "pm10"},
{sizeof(struct sensor_event_co2), "co2"},
{sizeof(struct sensor_event_hcho), "hcho"},
{sizeof(struct sensor_event_tvoc), "tvoc"},
{sizeof(struct sensor_event_ph), "ph"},
{sizeof(struct sensor_event_dust), "dust"},
{sizeof(struct sensor_event_hrate), "hrate"},
{sizeof(struct sensor_event_hbeat), "hbeat"},
{sizeof(struct sensor_event_ecg), "ecg"},
{sizeof(struct sensor_event_ppgd), "ppgd"},
{sizeof(struct sensor_event_ppgq), "ppgq"},
{sizeof(struct sensor_event_impd), "impd"},
{sizeof(struct sensor_event_ots), "ots"},
{sizeof(struct sensor_event_gps_satellite), "gps_satellite"},
};
static const struct file_operations g_sensor_fops =
{
sensor_open, /* open */
sensor_close, /* close */
sensor_read, /* read */
NULL, /* write */
NULL, /* seek */
sensor_ioctl, /* ioctl */
sensor_poll /* poll */
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL /* unlink */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
static void sensor_pollnotify(FAR struct sensor_upperhalf_s *upper,
pollevent_t eventset)
{
FAR struct pollfd *fd;
int semcount;
int i;
for (i = 0; i < CONFIG_SENSORS_NPOLLWAITERS; i++)
{
fd = upper->fds[i];
if (fd)
{
fd->revents |= (fd->events & eventset);
if (fd->revents != 0)
{
sninfo("Report events: %02x\n", fd->revents);
nxsem_get_value(fd->sem, &semcount);
if (semcount < 1)
{
nxsem_post(fd->sem);
}
}
}
}
}
static int sensor_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct sensor_upperhalf_s *upper = inode->i_private;
FAR struct sensor_lowerhalf_s *lower = upper->lower;
uint8_t tmp;
int ret;
ret = nxsem_wait(&upper->exclsem);
if (ret < 0)
{
return ret;
}
tmp = upper->crefs + 1;
if (tmp == 0)
{
/* More than 255 opens; uint8_t overflows to zero */
ret = -EMFILE;
goto err;
}
else if (tmp == 1)
{
/* Initialize sensor buffer */
ret = circbuf_init(&upper->buffer, NULL, lower->buffer_number *
upper->esize);
if (ret < 0)
{
goto err;
}
}
upper->crefs = tmp;
err:
nxsem_post(&upper->exclsem);
return ret;
}
static int sensor_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct sensor_upperhalf_s *upper = inode->i_private;
FAR struct sensor_lowerhalf_s *lower = upper->lower;
int ret;
ret = nxsem_wait(&upper->exclsem);
if (ret < 0)
{
return ret;
}
if (--upper->crefs <= 0 && upper->enabled)
{
ret = lower->ops->activate ?
lower->ops->activate(lower, false) : -ENOTSUP;
if (ret >= 0)
{
upper->enabled = false;
circbuf_uninit(&upper->buffer);
}
}
nxsem_post(&upper->exclsem);
return ret;
}
static ssize_t sensor_read(FAR struct file *filep, FAR char *buffer,
size_t len)
{
FAR struct inode *inode = filep->f_inode;
FAR struct sensor_upperhalf_s *upper = inode->i_private;
FAR struct sensor_lowerhalf_s *lower = upper->lower;
ssize_t ret;
if (!buffer || !len)
{
return -EINVAL;
}
ret = nxsem_wait(&upper->exclsem);
if (ret < 0)
{
return ret;
}
if (lower->ops->fetch)
{
if (!(filep->f_oflags & O_NONBLOCK))
{
nxsem_post(&upper->exclsem);
ret = nxsem_wait_uninterruptible(&upper->buffersem);
if (ret < 0)
{
return ret;
}
ret = nxsem_wait(&upper->exclsem);
if (ret < 0)
{
return ret;
}
}
else if (!upper->enabled)
{
ret = -EAGAIN;
goto out;
}
ret = lower->ops->fetch(lower, buffer, len);
}
else
{
/* We must make sure that when the semaphore is equal to 1, there must
* be events available in the buffer, so we use a while statement to
* synchronize this case that other read operations consume events
* that have just entered the buffer.
*/
while (circbuf_is_empty(&upper->buffer))
{
if (filep->f_oflags & O_NONBLOCK)
{
ret = -EAGAIN;
goto out;
}
else
{
nxsem_post(&upper->exclsem);
ret = nxsem_wait_uninterruptible(&upper->buffersem);
if (ret < 0)
{
return ret;
}
ret = nxsem_wait(&upper->exclsem);
if (ret < 0)
{
return ret;
}
}
}
ret = circbuf_read(&upper->buffer, buffer, len);
/* Release some buffer space when current mode isn't batch mode
* and last mode is batch mode, and the number of bytes available
* in buffer is less than the number of bytes origin.
*/
uint32_t buffer_size = lower->buffer_number * upper->esize;
if (upper->latency == 0 &&
circbuf_size(&upper->buffer) > buffer_size &&
circbuf_used(&upper->buffer) <= buffer_size)
{
ret = circbuf_resize(&upper->buffer, buffer_size);
}
}
out:
nxsem_post(&upper->exclsem);
return ret;
}
static int sensor_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct sensor_upperhalf_s *upper = inode->i_private;
FAR struct sensor_lowerhalf_s *lower = upper->lower;
FAR unsigned int *val = (unsigned int *)(uintptr_t)arg;
int ret;
sninfo("cmd=%x arg=%08lx\n", cmd, arg);
ret = nxsem_wait(&upper->exclsem);
if (ret < 0)
{
return ret;
}
switch (cmd)
{
case SNIOC_ACTIVATE:
{
if (upper->enabled == !!arg)
{
break;
}
ret = lower->ops->activate ?
lower->ops->activate(lower, !!arg) : -ENOTSUP;
if (ret >= 0)
{
upper->enabled = !!arg;
if (!upper->enabled)
{
upper->interval = 0;
upper->latency = 0;
ret = circbuf_resize(&upper->buffer, lower->buffer_number *
upper->esize);
}
}
}
break;
case SNIOC_SET_INTERVAL:
{
if (lower->ops->set_interval == NULL)
{
ret = -ENOTSUP;
break;
}
if (upper->interval == *val)
{
break;
}
ret = lower->ops->set_interval(lower, val);
if (ret >= 0)
{
upper->interval = *val;
}
}
break;
case SNIOC_BATCH:
{
if (lower->ops->batch == NULL)
{
ret = -ENOTSUP;
break;
}
if (upper->interval == 0)
{
ret = -EINVAL;
break;
}
if (upper->latency == *val)
{
break;
}
ret = lower->ops->batch(lower, val);
if (ret >= 0)
{
upper->latency = *val;
if (*val != 0)
{
/* Adjust length of buffer in batch mode */
uint32_t buffer_size = (ROUNDUP(*val, upper->interval) /
upper->interval +
lower->buffer_number) *
upper->esize;
ret = circbuf_resize(&upper->buffer, buffer_size);
}
}
}
break;
case SNIOC_SELFTEST:
{
if (lower->ops->selftest == NULL)
{
ret = -ENOTSUP;
break;
}
ret = lower->ops->selftest(lower, arg);
}
break;
case SNIOC_SET_CALIBVALUE:
{
if (lower->ops->set_calibvalue == NULL)
{
ret = -ENOTSUP;
break;
}
ret = lower->ops->set_calibvalue(lower, arg);
}
break;
case SNIOC_GET_NEVENTBUF:
{
*val = lower->buffer_number + lower->batch_number;
}
break;
case SNIOC_SET_BUFFER_NUMBER:
{
if (arg != 0)
{
lower->buffer_number = arg;
ret = circbuf_resize(&upper->buffer, arg * upper->esize);
}
}
break;
default:
/* Lowerhalf driver process other cmd. */
if (lower->ops->control)
{
ret = lower->ops->control(lower, cmd, arg);
}
else
{
ret = -ENOTTY;
}
break;
}
nxsem_post(&upper->exclsem);
return ret;
}
static int sensor_poll(FAR struct file *filep,
struct pollfd *fds, bool setup)
{
FAR struct inode *inode = filep->f_inode;
FAR struct sensor_upperhalf_s *upper = inode->i_private;
FAR struct sensor_lowerhalf_s *lower = upper->lower;
pollevent_t eventset = 0;
int semcount;
int ret;
int i;
ret = nxsem_wait(&upper->exclsem);
if (ret < 0)
{
return ret;
}
if (setup)
{
for (i = 0; i < CONFIG_SENSORS_NPOLLWAITERS; i++)
{
if (NULL == upper->fds[i])
{
upper->fds[i] = fds;
fds->priv = &upper->fds[i];
break;
}
}
/* Don't have enough space to store fds */
if (i == CONFIG_SENSORS_NPOLLWAITERS)
{
ret = -ENOSPC;
goto errout;
}
if (lower->ops->fetch)
{
/* Always return POLLIN for fetch data directly(non-block) */
if (filep->f_oflags & O_NONBLOCK)
{
eventset |= (fds->events & POLLIN);
}
else
{
nxsem_get_value(&upper->buffersem, &semcount);
if (semcount > 0)
{
eventset |= (fds->events & POLLIN);
}
}
}
else if (!circbuf_is_empty(&upper->buffer))
{
eventset |= (fds->events & POLLIN);
}
if (eventset)
{
sensor_pollnotify(upper, eventset);
}
}
else if (fds->priv != NULL)
{
for (i = 0; i < CONFIG_SENSORS_NPOLLWAITERS; i++)
{
if (fds == upper->fds[i])
{
upper->fds[i] = NULL;
fds->priv = NULL;
break;
}
}
}
errout:
nxsem_post(&upper->exclsem);
return ret;
}
static void sensor_push_event(FAR void *priv, FAR const void *data,
size_t bytes)
{
FAR struct sensor_upperhalf_s *upper = priv;
int semcount;
if (!bytes || nxsem_wait(&upper->exclsem) < 0)
{
return;
}
circbuf_overwrite(&upper->buffer, data, bytes);
sensor_pollnotify(upper, POLLIN);
nxsem_get_value(&upper->buffersem, &semcount);
if (semcount < 1)
{
nxsem_post(&upper->buffersem);
}
nxsem_post(&upper->exclsem);
}
static void sensor_notify_event(FAR void *priv)
{
FAR struct sensor_upperhalf_s *upper = priv;
int semcount;
if (nxsem_wait(&upper->exclsem) < 0)
{
return;
}
sensor_pollnotify(upper, POLLIN);
nxsem_get_value(&upper->buffersem, &semcount);
if (semcount < 1)
{
nxsem_post(&upper->buffersem);
}
nxsem_post(&upper->exclsem);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sensor_register
*
* Description:
* This function binds an instance of a "lower half" Sensor driver with the
* "upper half" Sensor device and registers that device so that can be used
* by application code.
*
* We will register the chararter device by node name format based on the
* type of sensor. Multiple types of the same type are distinguished by
* numbers. eg: accel0, accel1
*
* Input Parameters:
* dev - A pointer to an instance of lower half sensor driver. This
* instance is bound to the sensor driver and must persists as long
* as the driver persists.
* devno - The user specifies which device of this type, from 0. If the
* devno alerady exists, -EEXIST will be returned.
*
* Returned Value:
* OK if the driver was successfully register; A negated errno value is
* returned on any failure.
*
****************************************************************************/
int sensor_register(FAR struct sensor_lowerhalf_s *lower, int devno)
{
char path[DEVNAME_MAX];
DEBUGASSERT(lower != NULL);
snprintf(path, DEVNAME_MAX, DEVNAME_FMT,
g_sensor_info[lower->type].name,
lower->uncalibrated ? DEVNAME_UNCAL : "",
devno);
return sensor_custom_register(lower, path,
g_sensor_info[lower->type].esize);
}
/****************************************************************************
* Name: sensor_custom_register
*
* Description:
* This function binds an instance of a "lower half" Sensor driver with the
* "upper half" Sensor device and registers that device so that can be used
* by application code.
*
* You can register the character device type by specific path and esize.
* This API corresponds to the sensor_custom_unregister.
*
* Input Parameters:
* dev - A pointer to an instance of lower half sensor driver. This
* instance is bound to the sensor driver and must persists as long
* as the driver persists.
* path - The user specifies path of device. ex: /dev/sensor/xxx.
* esize - The element size of intermediate circular buffer.
*
* Returned Value:
* OK if the driver was successfully register; A negated errno value is
* returned on any failure.
*
****************************************************************************/
int sensor_custom_register(FAR struct sensor_lowerhalf_s *lower,
FAR const char *path, uint8_t esize)
{
FAR struct sensor_upperhalf_s *upper;
int ret = -EINVAL;
DEBUGASSERT(lower != NULL);
if (lower->type >= SENSOR_TYPE_COUNT || !esize)
{
snerr("ERROR: type is invalid\n");
return ret;
}
/* Allocate the upper-half data structure */
upper = kmm_zalloc(sizeof(struct sensor_upperhalf_s));
if (!upper)
{
snerr("ERROR: Allocation failed\n");
return -ENOMEM;
}
/* Initialize the upper-half data structure */
upper->lower = lower;
upper->esize = esize;
nxsem_init(&upper->exclsem, 0, 1);
nxsem_init(&upper->buffersem, 0, 0);
nxsem_set_protocol(&upper->buffersem, SEM_PRIO_NONE);
/* Bind the lower half data structure member */
lower->priv = upper;
if (!lower->ops->fetch)
{
if (!lower->buffer_number)
{
lower->buffer_number = 1;
}
lower->push_event = sensor_push_event;
}
else
{
lower->notify_event = sensor_notify_event;
lower->buffer_number = 0;
}
sninfo("Registering %s\n", path);
ret = register_driver(path, &g_sensor_fops, 0666, upper);
if (ret)
{
goto drv_err;
}
return ret;
drv_err:
nxsem_destroy(&upper->exclsem);
nxsem_destroy(&upper->buffersem);
kmm_free(upper);
return ret;
}
/****************************************************************************
* Name: sensor_unregister
*
* Description:
* This function unregister character node and release all resource about
* upper half driver.
*
* Input Parameters:
* dev - A pointer to an instance of lower half sensor driver. This
* instance is bound to the sensor driver and must persists as long
* as the driver persists.
* devno - The user specifies which device of this type, from 0.
****************************************************************************/
void sensor_unregister(FAR struct sensor_lowerhalf_s *lower, int devno)
{
char path[DEVNAME_MAX];
snprintf(path, DEVNAME_MAX, DEVNAME_FMT,
g_sensor_info[lower->type].name,
lower->uncalibrated ? DEVNAME_UNCAL : "",
devno);
sensor_custom_unregister(lower, path);
}
/****************************************************************************
* Name: sensor_custom_unregister
*
* Description:
* This function unregister character node and release all resource about
* upper half driver. This API corresponds to the sensor_custom_register.
*
* Input Parameters:
* dev - A pointer to an instance of lower half sensor driver. This
* instance is bound to the sensor driver and must persists as long
* as the driver persists.
* path - The user specifies path of device, ex: /dev/sensor/xxx
****************************************************************************/
void sensor_custom_unregister(FAR struct sensor_lowerhalf_s *lower,
FAR const char *path)
{
FAR struct sensor_upperhalf_s *upper;
DEBUGASSERT(lower != NULL);
DEBUGASSERT(lower->priv != NULL);
upper = lower->priv;
sninfo("UnRegistering %s\n", path);
unregister_driver(path);
nxsem_destroy(&upper->exclsem);
nxsem_destroy(&upper->buffersem);
kmm_free(upper);
}