zephyr/kernel/device.c

144 lines
3.4 KiB
C

/*
* Copyright (c) 2015-2016 Intel Corporation.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <string.h>
#include <zephyr/device.h>
#include <zephyr/sys/atomic.h>
#include <zephyr/sys/kobject.h>
#include <zephyr/syscall_handler.h>
extern const struct device __device_start[];
extern const struct device __device_end[];
/**
* @brief Initialize state for all static devices.
*
* The state object is always zero-initialized, but this may not be
* sufficient.
*/
void z_device_state_init(void)
{
const struct device *dev = __device_start;
while (dev < __device_end) {
z_object_init(dev);
++dev;
}
}
const struct device *z_impl_device_get_binding(const char *name)
{
const struct device *dev;
/* A null string identifies no device. So does an empty
* string.
*/
if ((name == NULL) || (name[0] == '\0')) {
return NULL;
}
/* Split the search into two loops: in the common scenario, where
* device names are stored in ROM (and are referenced by the user
* with CONFIG_* macros), only cheap pointer comparisons will be
* performed. Reserve string comparisons for a fallback.
*/
for (dev = __device_start; dev != __device_end; dev++) {
if (z_device_is_ready(dev) && (dev->name == name)) {
return dev;
}
}
for (dev = __device_start; dev != __device_end; dev++) {
if (z_device_is_ready(dev) && (strcmp(name, dev->name) == 0)) {
return dev;
}
}
return NULL;
}
#ifdef CONFIG_USERSPACE
static inline const struct device *z_vrfy_device_get_binding(const char *name)
{
char name_copy[Z_DEVICE_MAX_NAME_LEN];
if (z_user_string_copy(name_copy, (char *)name, sizeof(name_copy))
!= 0) {
return NULL;
}
return z_impl_device_get_binding(name_copy);
}
#include <syscalls/device_get_binding_mrsh.c>
static inline bool z_vrfy_device_is_ready(const struct device *dev)
{
Z_OOPS(Z_SYSCALL_OBJ_INIT(dev, K_OBJ_ANY));
return z_impl_device_is_ready(dev);
}
#include <syscalls/device_is_ready_mrsh.c>
#endif /* CONFIG_USERSPACE */
size_t z_device_get_all_static(struct device const **devices)
{
*devices = __device_start;
return __device_end - __device_start;
}
bool z_device_is_ready(const struct device *dev)
{
/*
* if an invalid device pointer is passed as argument, this call
* reports the `device` as not ready for usage.
*/
if (dev == NULL) {
return false;
}
return dev->state->initialized && (dev->state->init_res == 0U);
}
static int device_visitor(const device_handle_t *handles,
size_t handle_count,
device_visitor_callback_t visitor_cb,
void *context)
{
/* Iterate over fixed devices */
for (size_t i = 0; i < handle_count; ++i) {
device_handle_t dh = handles[i];
const struct device *rdev = device_from_handle(dh);
int rc = visitor_cb(rdev, context);
if (rc < 0) {
return rc;
}
}
return handle_count;
}
int device_required_foreach(const struct device *dev,
device_visitor_callback_t visitor_cb,
void *context)
{
size_t handle_count = 0;
const device_handle_t *handles = device_required_handles_get(dev, &handle_count);
return device_visitor(handles, handle_count, visitor_cb, context);
}
int device_supported_foreach(const struct device *dev,
device_visitor_callback_t visitor_cb,
void *context)
{
size_t handle_count = 0;
const device_handle_t *handles = device_supported_handles_get(dev, &handle_count);
return device_visitor(handles, handle_count, visitor_cb, context);
}