zephyr/include/device.h

363 lines
10 KiB
C

/*
* Copyright (c) 2015 Intel Corporation.
*
* Licensed 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.
*/
#ifndef _DEVICE_H_
#define _DEVICE_H_
/**
* @brief Device Driver APIs
* @defgroup io_interfaces Device Driver APIs
* @{
* @}
*/
/**
* @brief Device Model APIs
* @defgroup device_model Device Model APIs
* @{
*/
#ifdef __cplusplus
extern "C" {
#endif
/**
* @def DEVICE_INIT
*
* @brief create device object and set it up for boot time initialization
*
* @details This macro defines a device object that is automatically
* configured by the kernel during system initialization.
*
* @param dev_name Device name.
*
* @param drv_name The name this instance of the driver exposes to
* the system.
*
* @param init_fn Address to the init function of the driver.
*
* @param data Pointer to the device's configuration data.
*
* @param cfg_info The address to the structure containing the
* configuration information for this instance of the driver.
*
* @param level The initialization level at which configuration occurs.
* Must be one of the following symbols, which are listed in the order
* they are performed by the kernel:
*
* PRIMARY: Used for devices that have no dependencies, such as those
* that rely solely on hardware present in the processor/SOC. These devices
* cannot use any kernel services during configuration, since they are not
* yet available.
*
* SECONDARY: Used for devices that rely on the initialization of devices
* initialized as part of the PRIMARY level. These devices cannot use any
* kernel services during configuration, since they are not yet available.
*
* NANOKERNEL: Used for devices that require nanokernel services during
* configuration.
*
* MICROKERNEL: Used for devices that require microkernel services during
* configuration.
*
* APPLICATION: Used for application components (i.e. non-kernel components)
* that need automatic configuration. These devices can use all services
* provided by the kernel during configuration.
*
* @param prio The initialization priority of the device, relative to
* other devices of the same initialization level. Specified as an integer
* value in the range 0 to 99; lower values indicate earlier initialization.
* Must be a decimal integer literal without leading zeroes or sign (e.g. 32),
* or an equivalent symbolic name (e.g. \#define MY_INIT_PRIO 32); symbolic
* expressions are *not* permitted
* (e.g. CONFIG_KERNEL_INIT_PRIORITY_DEFAULT + 5).
*/
#define DEVICE_INIT(dev_name, drv_name, init_fn, data, cfg_info, level, prio) \
\
static struct device_config __config_##dev_name __used \
__attribute__((__section__(".devconfig.init"))) = { \
.name = drv_name, .init = (init_fn), \
.config_info = (cfg_info) \
}; \
\
static struct device (__device_##dev_name) __used \
__attribute__((__section__(".init_" #level STRINGIFY(prio)))) = { \
.config = &(__config_##dev_name), \
.driver_data = data \
}
/**
* @def DEVICE_NAME_GET
*
* @brief Expands to the full name of a global device object
*
* @details Return the full name of a device object symbol created by
* DEVICE_INIT(), using the dev_name provided to DEVICE_INIT().
*
* It is meant to be used for declaring extern symbols pointing on device
* objects before using the DEVICE_GET macro to get the device object.
*
* @param name The same as dev_name provided to DEVICE_INIT()
*
* @return The exanded name of the device object created by DEVICE_INIT()
*/
#define DEVICE_NAME_GET(name) (_CONCAT(__device_, name))
/**
* @def DEVICE_GET
*
* @brief Obtain a pointer to a device object by name
*
* @details Return the address of a device object created by
* DEVICE_INIT(), using the dev_name provided to DEVICE_INIT().
*
* @param name The same as dev_name provided to DEVICE_INIT()
*
* @return A pointer to the device object created by DEVICE_INIT()
*/
#define DEVICE_GET(name) (&DEVICE_NAME_GET(name))
/** @def DEVICE_DECLARE
*
* @brief Declare a device object
*
* This macro can be used at the top-level to declare a device, such
* that DEVICE_GET() may be used before the full declaration in
* DEVICE_INIT(), or reference the device in another C file.
*
* This is often useful when configuring interrupts statically in a
* device's init or per-instance config function, as the init function
* itself is required by DEVICE_INIT() and use of DEVICE_GET()
* inside it creates a circular dependeny.
*
* @param name Device name
*/
#define DEVICE_DECLARE(name) extern struct device DEVICE_NAME_GET(name)
/* Common Error Codes devices can provide */
#define DEV_OK 0 /* No error */
#define DEV_FAIL 1 /* General operation failure */
#define DEV_INVALID_OP 2 /* Invalid operation */
#define DEV_INVALID_CONF 3 /* Invalid configuration */
#define DEV_USED 4 /* Device controller in use */
#define DEV_NO_ACCESS 5 /* Controller not accessible */
#define DEV_NO_SUPPORT 6 /* Device type not supported */
#define DEV_NOT_CONFIG 7 /* Device not configured */
struct device;
/**
* @brief Static device information (In ROM) Per driver instance
* @param name name of the device
* @param init init function for the driver
* @param config_info address of driver instance config information
*/
struct device_config {
char *name;
int (*init)(struct device *device);
void *config_info;
};
/**
* @brief Runtime device structure (In memory) Per driver instance
* @param device_config Build time config information
* @param driver_api pointer to structure containing the API functions for
* the device type. This pointer is filled in by the driver at init time.
* @param driver_data river instance data. For driver use only
*/
struct device {
struct device_config *config;
void *driver_api;
void *driver_data;
};
void _sys_device_do_config_level(int level);
struct device* device_get_binding(char *name);
/**
* Synchronous calls API
*/
#include <stdbool.h>
#include <nanokernel.h>
#ifdef CONFIG_MICROKERNEL
#include <microkernel.h>
#endif
#ifdef CONFIG_MICROKERNEL
enum device_sync_waiter {
DEVICE_SYNC_WAITER_NONE,
DEVICE_SYNC_WAITER_FIBER,
DEVICE_SYNC_WAITER_TASK,
};
#endif
/**
* Specific type for synchronizing calls among the 2 possible contexts
*/
typedef struct {
/** Nanokernel semaphore used for fiber context */
struct nano_sem f_sem;
#ifdef CONFIG_MICROKERNEL
/** Microkernel semaphore used for task context */
struct _k_sem_struct _t_sem;
ksem_t t_sem;
enum device_sync_waiter waiter;
bool device_ready;
#endif
} device_sync_call_t;
/**
* @brief Initialize the context-dependent synchronization data
*
* @param sync A pointer to a valid device_sync_call_t
*/
static inline void device_sync_call_init(device_sync_call_t *sync)
{
nano_sem_init(&sync->f_sem);
#ifdef CONFIG_MICROKERNEL
sync->_t_sem.waiters = NULL;
sync->_t_sem.level = sync->_t_sem.count = 0;
sync->t_sem = (ksem_t)&sync->_t_sem;
sync->waiter = DEVICE_SYNC_WAITER_NONE;
sync->device_ready = false;
#endif
}
#ifdef CONFIG_MICROKERNEL
/*
* The idle task cannot block and is used during boot, and thus polls a
* nanokernel semaphore instead of waiting on a microkernel semaphore.
*/
static inline bool _is_blocking_task(void)
{
bool is_task = sys_execution_context_type_get() == NANO_CTX_TASK;
bool is_idle_task = task_priority_get() == (CONFIG_NUM_TASK_PRIORITIES - 1);
return is_task && !is_idle_task;
}
/**
* @brief Wait for the isr to complete the synchronous call
* Note: In a microkernel built this function will take care of the caller
* context and thus use the right attribute to handle the synchronization.
*
* @param sync A pointer to a valid device_sync_call_t
*/
static inline void device_sync_call_wait(device_sync_call_t *sync)
{
/* protect the state of device_ready and waiter fields */
int key = irq_lock();
if (sync->device_ready) {
sync->device_ready = false;
/*
* If device_ready was set, the waiter field had to be NONE, so we
* don't have to reset it.
*/
irq_unlock(key);
return;
}
if (_is_blocking_task()) {
sync->waiter = DEVICE_SYNC_WAITER_TASK;
irq_unlock(key);
task_sem_take(sync->t_sem, TICKS_UNLIMITED);
} else {
sync->waiter = DEVICE_SYNC_WAITER_FIBER;
irq_unlock(key);
nano_sem_take(&sync->f_sem, TICKS_UNLIMITED);
}
sync->waiter = DEVICE_SYNC_WAITER_NONE;
/* if we get here, device_ready was not set: we don't have to reset it */
}
/**
* @brief Signal the waiter about synchronization completion
* Note: In a microkernel built this function will take care of the waiter
* context and thus use the right attribute to signale the completion.
*
* @param sync A pointer to a valid device_sync_call_t
*/
static inline void device_sync_call_complete(device_sync_call_t *sync)
{
static void (*func[3])(ksem_t sema) = {
isr_sem_give,
fiber_sem_give,
task_sem_give
};
/* protect the state of device_ready and waiter fields */
int key = irq_lock();
if (sync->waiter == DEVICE_SYNC_WAITER_NONE) {
sync->device_ready = true;
irq_unlock(key);
return;
}
/*
* It's safe to unlock interrupts here since we know there was a waiter,
* and only one thread is allowed to wait on the object, so the state of
* waiter will not change and the device_ready flag will not get set.
*/
irq_unlock(key);
if (sync->waiter == DEVICE_SYNC_WAITER_TASK) {
func[sys_execution_context_type_get()](sync->t_sem);
} else /* fiber */ {
nano_sem_give(&sync->f_sem);
}
}
#else
/**
* @brief Wait for the isr to complete the synchronous call
* Note: It will simply wait on the internal semaphore.
*
* @param sync A pointer to a valid device_sync_call_t
*/
static inline void device_sync_call_wait(device_sync_call_t *sync)
{
nano_sem_take(&sync->f_sem, TICKS_UNLIMITED);
}
/**
* @brief Signal the waiter about synchronization completion
* Note: It will simply release the internal semaphore
*
* @param sync A pointer to a valid device_sync_call_t
*/
static inline void device_sync_call_complete(device_sync_call_t *sync)
{
nano_sem_give(&sync->f_sem);
}
#endif /* CONFIG_MICROKERNEL || CONFIG_NANOKERNEL */
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* _DEVICE_H_ */