zephyr/include/device.h

438 lines
13 KiB
C

/*
* Copyright (c) 2015 Intel Corporation.
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_DEVICE_H_
#define ZEPHYR_INCLUDE_DEVICE_H_
#include <kernel.h>
/**
* @brief Device Driver APIs
* @defgroup io_interfaces Device Driver APIs
* @{
* @}
*/
/**
* @brief Device Model APIs
* @defgroup device_model Device Model APIs
* @{
*/
#include <zephyr/types.h>
#ifdef __cplusplus
extern "C" {
#endif
static const int _INIT_LEVEL_PRE_KERNEL_1 = 1;
static const int _INIT_LEVEL_PRE_KERNEL_2 = 1;
static const int _INIT_LEVEL_POST_KERNEL = 1;
static const int _INIT_LEVEL_APPLICATION = 1;
/**
* @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:
* \n
* \li PRE_KERNEL_1: 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.
* \n
* \li PRE_KERNEL_2: 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.
* \n
* \li POST_KERNEL: Used for devices that require kernel services during
* configuration.
* \n
* \li 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) \
DEVICE_AND_API_INIT(dev_name, drv_name, init_fn, data, cfg_info, \
level, prio, NULL)
/**
* @def DEVICE_AND_API_INIT
*
* @brief Create device object and set it up for boot time initialization,
* with the option to set driver_api.
*
* @copydetails DEVICE_INIT
* @param api Provides an initial pointer to the API function struct
* used by the driver. Can be NULL.
* @details The driver api is also set here, eliminating the need to do that
* during initialization.
*/
#ifndef CONFIG_DEVICE_POWER_MANAGEMENT
#define DEVICE_AND_API_INIT(dev_name, drv_name, init_fn, data, cfg_info, \
level, prio, api) \
static struct device_config _CONCAT(__config_, dev_name) __used \
__attribute__((__section__(".devconfig.init"))) = { \
.name = drv_name, .init = (init_fn), \
.config_info = (cfg_info) \
}; \
static struct device _CONCAT(__device_, dev_name) __used \
__attribute__((__section__(".init_" #level STRINGIFY(prio)))) = { \
.config = &_CONCAT(__config_, dev_name), \
.driver_api = api, \
.driver_data = data \
}
#else
/*
* Use the default device_pm_control for devices that do not call the
* DEVICE_DEFINE macro so that caller of hook functions
* need not check device_pm_control != NULL.
*/
#define DEVICE_AND_API_INIT(dev_name, drv_name, init_fn, data, cfg_info, \
level, prio, api) \
DEVICE_DEFINE(dev_name, drv_name, init_fn, \
device_pm_control_nop, data, cfg_info, level, \
prio, api)
#endif
/**
* @def DEVICE_DEFINE
*
* @brief Create device object and set it up for boot time initialization,
* with the option to device_pm_control.
*
* @copydetails DEVICE_AND_API_INIT
* @param pm_control_fn Pointer to device_pm_control function.
* Can be empty function (device_pm_control_nop) if not implemented.
*/
#ifndef CONFIG_DEVICE_POWER_MANAGEMENT
#define DEVICE_DEFINE(dev_name, drv_name, init_fn, pm_control_fn, \
data, cfg_info, level, prio, api) \
DEVICE_AND_API_INIT(dev_name, drv_name, init_fn, data, cfg_info, \
level, prio, api)
#else
#define DEVICE_DEFINE(dev_name, drv_name, init_fn, pm_control_fn, \
data, cfg_info, level, prio, api) \
static struct device_config _CONCAT(__config_, dev_name) __used \
__attribute__((__section__(".devconfig.init"))) = { \
.name = drv_name, .init = (init_fn), \
.device_pm_control = (pm_control_fn), \
.config_info = (cfg_info) \
}; \
static struct device _CONCAT(__device_, dev_name) __used \
__attribute__((__section__(".init_" #level STRINGIFY(prio)))) = { \
.config = &_CONCAT(__config_, dev_name), \
.driver_api = api, \
.driver_data = data \
}
#endif
/**
* @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 expanded 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 static 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().
*
* 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 dependency.
*
* @param name Device name
*/
#define DEVICE_DECLARE(name) static struct device DEVICE_NAME_GET(name)
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 {
const char *name;
int (*init)(struct device *device);
#ifdef CONFIG_DEVICE_POWER_MANAGEMENT
int (*device_pm_control)(struct device *device, u32_t command,
void *context);
#endif
const 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 driver instance data. For driver use only
*/
struct device {
struct device_config *config;
const void *driver_api;
void *driver_data;
};
void _sys_device_do_config_level(int level);
/**
* @brief Retrieve the device structure for a driver by name
*
* @details Device objects are created via the DEVICE_INIT() macro and
* placed in memory by the linker. If a driver needs to bind to another driver
* it can use this function to retrieve the device structure of the lower level
* driver by the name the driver exposes to the system.
*
* @param name device name to search for.
*
* @return pointer to device structure; NULL if not found or cannot be used.
*/
struct device *device_get_binding(const char *name);
/**
* @brief Device Power Management APIs
* @defgroup device_power_management_api Device Power Management APIs
* @ingroup power_management_api
* @{
*/
#ifdef CONFIG_DEVICE_POWER_MANAGEMENT
/** @def DEVICE_PM_ACTIVE_STATE
*
* @brief device is in ACTIVE power state
*
* @details Normal operation of the device. All device context is retained.
*/
#define DEVICE_PM_ACTIVE_STATE 1
/** @def DEVICE_PM_LOW_POWER_STATE
*
* @brief device is in LOW power state
*
* @details Device context is preserved by the HW and need not be
* restored by the driver.
*/
#define DEVICE_PM_LOW_POWER_STATE 2
/** @def DEVICE_PM_SUSPEND_STATE
*
* @brief device is in SUSPEND power state
*
* @details Most device context is lost by the hardware.
* Device drivers must save and restore or reinitialize any context
* lost by the hardware
*/
#define DEVICE_PM_SUSPEND_STATE 3
/** @def DEVICE_PM_OFF_STATE
*
* @brief device is in OFF power state
*
* @details - Power has been fully removed from the device.
* The device context is lost when this state is entered, so the OS
* software will reinitialize the device when powering it back on
*/
#define DEVICE_PM_OFF_STATE 4
/* Constants defining support device power commands */
#define DEVICE_PM_SET_POWER_STATE 1
#define DEVICE_PM_GET_POWER_STATE 2
#endif /* CONFIG_DEVICE_POWER_MANAGEMENT */
/**
* @brief Indicate that the device is in the middle of a transaction
*
* Called by a device driver to indicate that it is in the middle of a
* transaction.
*
* @param busy_dev Pointer to device structure of the driver instance.
*/
void device_busy_set(struct device *busy_dev);
/**
* @brief Indicate that the device has completed its transaction
*
* Called by a device driver to indicate the end of a transaction.
*
* @param busy_dev Pointer to device structure of the driver instance.
*/
void device_busy_clear(struct device *busy_dev);
#ifdef CONFIG_DEVICE_POWER_MANAGEMENT
/*
* Device PM functions
*/
/**
* @brief No-op function to initialize unimplemented hook
*
* This function should be used to initialize device hook
* for which a device has no PM operations.
*
* @param unused_device Unused
* @param unused_ctrl_command Unused
* @param unused_context Unused
*
* @retval 0 Always returns 0
*/
int device_pm_control_nop(struct device *unused_device,
u32_t unused_ctrl_command, void *unused_context);
/**
* @brief Call the set power state function of a device
*
* Called by the application or power management service to let the device do
* required operations when moving to the required power state
* Note that devices may support just some of the device power states
* @param device Pointer to device structure of the driver instance.
* @param device_power_state Device power state to be set
*
* @retval 0 If successful.
* @retval Errno Negative errno code if failure.
*/
static inline int device_set_power_state(struct device *device,
u32_t device_power_state)
{
return device->config->device_pm_control(device,
DEVICE_PM_SET_POWER_STATE,
&device_power_state);
}
/**
* @brief Call the get power state function of a device
*
* This function lets the caller know the current device
* power state at any time. This state will be one of the defined
* power states allowed for the devices in that system
*
* @param device pointer to device structure of the driver instance.
* @param device_power_state Device power state to be filled by the device
*
* @retval 0 If successful.
* @retval Errno Negative errno code if failure.
*/
static inline int device_get_power_state(struct device *device,
u32_t *device_power_state)
{
return device->config->device_pm_control(device,
DEVICE_PM_GET_POWER_STATE,
device_power_state);
}
/**
* @brief Gets the device structure list array and device count
*
* Called by the Power Manager application to get the list of
* device structures associated with the devices in the system.
* The PM app would use this list to create its own sorted list
* based on the order it wishes to suspend or resume the devices.
*
* @param device_list Pointer to receive the device list array
* @param device_count Pointer to receive the device count
*/
void device_list_get(struct device **device_list, int *device_count);
/**
* @brief Check if any device is in the middle of a transaction
*
* Called by an application to see if any device is in the middle
* of a critical transaction that cannot be interrupted.
*
* @retval 0 if no device is busy
* @retval -EBUSY if any device is busy
*/
int device_any_busy_check(void);
/**
* @brief Check if a specific device is in the middle of a transaction
*
* Called by an application to see if a particular device is in the
* middle of a critical transaction that cannot be interrupted.
*
* @param chk_dev Pointer to device structure of the specific device driver
* the caller is interested in.
* @retval 0 if the device is not busy
* @retval -EBUSY if the device is busy
*/
int device_busy_check(struct device *chk_dev);
#endif
/**
* @}
*/
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* ZEPHYR_INCLUDE_DEVICE_H_ */