blob: b80a6b1e8c4f0084b133d10142f01c5b609cf01e [file] [log] [blame]
/*
* Copyright (c) 2015 Intel Corporation.
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_DEVICE_H_
#define ZEPHYR_INCLUDE_DEVICE_H_
/**
* @brief Device Driver APIs
* @defgroup io_interfaces Device Driver APIs
* @{
* @}
*/
/**
* @brief Miscellaneous Drivers APIs
* @defgroup misc_interfaces Miscellaneous Drivers APIs
* @ingroup io_interfaces
* @{
* @}
*/
/**
* @brief Device Model APIs
* @defgroup device_model Device Model APIs
* @{
*/
#include <zephyr/init.h>
#include <zephyr/linker/sections.h>
#include <zephyr/sys/device_mmio.h>
#include <zephyr/sys/util.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Type used to represent a "handle" for a device.
*
* Every struct device has an associated handle. You can get a pointer
* to a device structure from its handle and vice versa, but the
* handle uses less space than a pointer. The device.h API mainly uses
* handles to store lists of multiple devices in a compact way.
*
* The extreme values and zero have special significance. Negative
* values identify functionality that does not correspond to a Zephyr
* device, such as the system clock or a SYS_INIT() function.
*
* @see device_handle_get()
* @see device_from_handle()
*/
typedef int16_t device_handle_t;
/** @brief Flag value used in lists of device handles to separate
* distinct groups.
*
* This is the minimum value for the device_handle_t type.
*/
#define DEVICE_HANDLE_SEP INT16_MIN
/** @brief Flag value used in lists of device handles to indicate the
* end of the list.
*
* This is the maximum value for the device_handle_t type.
*/
#define DEVICE_HANDLE_ENDS INT16_MAX
/** @brief Flag value used to identify an unknown device. */
#define DEVICE_HANDLE_NULL 0
#define Z_DEVICE_MAX_NAME_LEN 48
/**
* @def DEVICE_NAME_GET
*
* @brief Expands to the name of a global device object.
*
* @details Return the full name of a device object symbol created by
* DEVICE_DEFINE(), using the dev_name provided to DEVICE_DEFINE().
* This is the name of the global variable storing the device
* structure, not a pointer to the string in the device's @p name
* field.
*
* It is meant to be used for declaring extern symbols pointing to device
* objects before using the DEVICE_GET macro to get the device object.
*
* This macro is normally only useful within device driver source
* code. In other situations, you are probably looking for
* device_get_binding().
*
* @param name The same @p dev_name token given to DEVICE_DEFINE()
*
* @return The full name of the device object defined by DEVICE_DEFINE()
*/
#define DEVICE_NAME_GET(name) _CONCAT(__device_, name)
/* Node paths can exceed the maximum size supported by device_get_binding() in user mode,
* so synthesize a unique dev_name from the devicetree node.
*
* The ordinal used in this name can be mapped to the path by
* examining zephyr/include/generated/device_extern.h header. If the
* format of this conversion changes, gen_defines should be updated to
* match it.
*/
#define Z_DEVICE_DT_DEV_NAME(node_id) _CONCAT(dts_ord_, DT_DEP_ORD(node_id))
/* Synthesize a unique name for the device state associated with
* dev_name.
*/
#define Z_DEVICE_STATE_NAME(dev_name) _CONCAT(__devstate_, dev_name)
/**
* @brief Utility macro to define and initialize the device state.
*
* @param node_id Devicetree node id of the device.
* @param dev_name Device name.
*/
#define Z_DEVICE_STATE_DEFINE(node_id, dev_name) \
static struct device_state Z_DEVICE_STATE_NAME(dev_name) \
__attribute__((__section__(".z_devstate")));
/**
* @def DEVICE_DEFINE
*
* @brief Create a device object and set it up for boot time initialization.
*
* @details This macro defines a <tt>struct device</tt> that is
* automatically configured by the kernel during system
* initialization. This macro should only be used when the device is
* not being allocated from a devicetree node. If you are allocating a
* device from a devicetree node, use DEVICE_DT_DEFINE() or
* DEVICE_DT_INST_DEFINE() instead.
*
* @param dev_name A unique token which is used in the name of the
* global device structure as a C identifier.
*
* @param drv_name A string name for the device, which will be stored
* in the device structure's @p name field. This name can be used to
* look up the device with device_get_binding(). This must be less
* than Z_DEVICE_MAX_NAME_LEN characters (including terminating NUL)
* in order to be looked up from user mode.
*
* @param init_fn Pointer to the device's initialization function,
* which will be run by the kernel during system initialization.
*
* @param pm_device Pointer to the device's power management
* resources, a <tt>struct pm_device</tt>, which will be stored in the
* device structure's @p pm field. Use NULL if the device does not use
* PM.
*
* @param data_ptr Pointer to the device's private mutable data, which
* will be stored in the device structure's @p data field.
*
* @param cfg_ptr Pointer to the device's private constant data, which
* will be stored in the device structure's @p config field.
*
* @param level The device's initialization level. See SYS_INIT() for
* details.
*
* @param prio The device's priority within its initialization level.
* See SYS_INIT() for details.
*
* @param api_ptr Pointer to the device's API structure. Can be NULL.
*/
#define DEVICE_DEFINE(dev_name, drv_name, init_fn, pm_device, \
data_ptr, cfg_ptr, level, prio, api_ptr) \
Z_DEVICE_STATE_DEFINE(DT_INVALID_NODE, dev_name) \
Z_DEVICE_DEFINE(DT_INVALID_NODE, dev_name, drv_name, init_fn, \
pm_device, \
data_ptr, cfg_ptr, level, prio, api_ptr, \
&Z_DEVICE_STATE_NAME(dev_name))
/**
* @def DEVICE_DT_NAME
*
* @brief Return a string name for a devicetree node.
*
* @details This macro returns a string literal usable as a device's
* @p name field from a devicetree node identifier.
*
* @param node_id The devicetree node identifier.
*
* @return The value of the node's "label" property, if it has one.
* Otherwise, the node's full name in "node-name@@unit-address" form.
*/
#define DEVICE_DT_NAME(node_id) \
DT_PROP_OR(node_id, label, DT_NODE_FULL_NAME(node_id))
/**
* @def DEVICE_DT_DEFINE
*
* @brief Create a device object from a devicetree node identifier and
* set it up for boot time initialization.
*
* @details This macro defines a <tt>struct device</tt> that is
* automatically configured by the kernel during system
* initialization. The global device object's name as a C identifier
* is derived from the node's dependency ordinal. The device
* structure's @p name field is set to
* <tt>DEVICE_DT_NAME(node_id)</tt>.
*
* The device is declared with extern visibility, so a pointer to a
* global device object can be obtained with
* <tt>DEVICE_DT_GET(node_id)</tt> from any source file that includes
* device.h. Before using the pointer, the referenced object should be
* checked using device_is_ready().
*
* @param node_id The devicetree node identifier.
*
* @param init_fn Pointer to the device's initialization function,
* which will be run by the kernel during system initialization.
*
* @param pm_device Pointer to the device's power management
* resources, a <tt>struct pm_device</tt>, which will be stored in the
* device structure's @p pm field. Use NULL if the device does not use
* PM.
*
* @param data_ptr Pointer to the device's private mutable data, which
* will be stored in the device structure's @p data field.
*
* @param cfg_ptr Pointer to the device's private constant data, which
* will be stored in the device structure's @p config field.
*
* @param level The device's initialization level. See SYS_INIT() for
* details.
*
* @param prio The device's priority within its initialization level.
* See SYS_INIT() for details.
*
* @param api_ptr Pointer to the device's API structure. Can be NULL.
*/
#define DEVICE_DT_DEFINE(node_id, init_fn, pm_device, \
data_ptr, cfg_ptr, level, prio, \
api_ptr, ...) \
Z_DEVICE_STATE_DEFINE(node_id, Z_DEVICE_DT_DEV_NAME(node_id)) \
Z_DEVICE_DEFINE(node_id, Z_DEVICE_DT_DEV_NAME(node_id), \
DEVICE_DT_NAME(node_id), init_fn, \
pm_device, \
data_ptr, cfg_ptr, level, prio, \
api_ptr, \
&Z_DEVICE_STATE_NAME(Z_DEVICE_DT_DEV_NAME(node_id)), \
__VA_ARGS__)
/**
* @def DEVICE_DT_INST_DEFINE
*
* @brief Like DEVICE_DT_DEFINE(), but uses an instance of a
* DT_DRV_COMPAT compatible instead of a node identifier.
*
* @param inst instance number. The @p node_id argument to
* DEVICE_DT_DEFINE is set to <tt>DT_DRV_INST(inst)</tt>.
*
* @param ... other parameters as expected by DEVICE_DT_DEFINE.
*/
#define DEVICE_DT_INST_DEFINE(inst, ...) \
DEVICE_DT_DEFINE(DT_DRV_INST(inst), __VA_ARGS__)
/**
* @def DEVICE_DT_NAME_GET
*
* @brief The name of the global device object for @p node_id
*
* @details Returns the name of the global device structure as a C
* identifier. The device must be allocated using DEVICE_DT_DEFINE()
* or DEVICE_DT_INST_DEFINE() for this to work.
*
* This macro is normally only useful within device driver source
* code. In other situations, you are probably looking for
* DEVICE_DT_GET().
*
* @param node_id Devicetree node identifier
*
* @return The name of the device object as a C identifier
*/
#define DEVICE_DT_NAME_GET(node_id) DEVICE_NAME_GET(Z_DEVICE_DT_DEV_NAME(node_id))
/**
* @def DEVICE_DT_GET
*
* @brief Get a <tt>const struct device*</tt> from a devicetree node
* identifier
*
* @details Returns a pointer to a device object created from a
* devicetree node, if any device was allocated by a driver.
*
* If no such device was allocated, this will fail at linker time. If
* you get an error that looks like <tt>undefined reference to
* __device_dts_ord_<N></tt>, that is what happened. Check to make
* sure your device driver is being compiled, usually by enabling the
* Kconfig options it requires.
*
* @param node_id A devicetree node identifier
* @return A pointer to the device object created for that node
*/
#define DEVICE_DT_GET(node_id) (&DEVICE_DT_NAME_GET(node_id))
/** @def DEVICE_DT_INST_GET
*
* @brief Get a <tt>const struct device*</tt> for an instance of a
* DT_DRV_COMPAT compatible
*
* @details This is equivalent to <tt>DEVICE_DT_GET(DT_DRV_INST(inst))</tt>.
*
* @param inst DT_DRV_COMPAT instance number
* @return A pointer to the device object created for that instance
*/
#define DEVICE_DT_INST_GET(inst) DEVICE_DT_GET(DT_DRV_INST(inst))
/**
* @def DEVICE_DT_GET_ANY
*
* @brief Get a <tt>const struct device*</tt> from a devicetree compatible
*
* If an enabled devicetree node has the given compatible and a device
* object was created from it, this returns a pointer to that device.
*
* If there no such devices, this returns NULL.
*
* If there are multiple, this returns an arbitrary one.
*
* If this returns non-NULL, the device must be checked for readiness
* before use, e.g. with device_is_ready().
*
* @param compat lowercase-and-underscores devicetree compatible
* @return a pointer to a device, or NULL
*/
#define DEVICE_DT_GET_ANY(compat) \
COND_CODE_1(DT_HAS_COMPAT_STATUS_OKAY(compat), \
(DEVICE_DT_GET(DT_COMPAT_GET_ANY_STATUS_OKAY(compat))), \
(NULL))
/**
* @def DEVICE_DT_GET_ONE
*
* @brief Get a <tt>const struct device*</tt> from a devicetree compatible
*
* @details If an enabled devicetree node has the given compatible and
* a device object was created from it, this returns a pointer to that
* device.
*
* If there no such devices, this will fail at compile time.
*
* If there are multiple, this returns an arbitrary one.
*
* If this returns non-NULL, the device must be checked for readiness
* before use, e.g. with device_is_ready().
*
* @param compat lowercase-and-underscores devicetree compatible
* @return a pointer to a device
*/
#define DEVICE_DT_GET_ONE(compat) \
COND_CODE_1(DT_HAS_COMPAT_STATUS_OKAY(compat), \
(DEVICE_DT_GET(DT_COMPAT_GET_ANY_STATUS_OKAY(compat))), \
(ZERO_OR_COMPILE_ERROR(0)))
/**
* @def DEVICE_DT_GET_OR_NULL
*
* @brief Utility macro to obtain an optional reference to a device.
*
* @details If the node identifier refers to a node with status
* "okay", this returns <tt>DEVICE_DT_GET(node_id)</tt>. Otherwise, it
* returns NULL.
*
* @param node_id devicetree node identifier
*
* @return a <tt>const struct device*</tt> for the node identifier,
* which may be NULL.
*/
#define DEVICE_DT_GET_OR_NULL(node_id) \
COND_CODE_1(DT_NODE_HAS_STATUS(node_id, okay), \
(DEVICE_DT_GET(node_id)), (NULL))
/**
* @def DEVICE_GET
*
* @brief Obtain a pointer to a device object by name
*
* @details Return the address of a device object created by
* DEVICE_DEFINE(), using the dev_name provided to DEVICE_DEFINE().
*
* @param name The same as dev_name provided to DEVICE_DEFINE()
*
* @return A pointer to the device object created by DEVICE_DEFINE()
*/
#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_DEFINE().
*
* 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_DEFINE() and use of DEVICE_GET()
* inside it creates a circular dependency.
*
* @param name Device name
*/
#define DEVICE_DECLARE(name) static const struct device DEVICE_NAME_GET(name)
/**
* @def DEVICE_INIT_DT_GET
*
* @brief Get a <tt>const struct init_entry*</tt> from a devicetree node
*
* @param node_id A devicetree node identifier
*
* @return A pointer to the init_entry object created for that node
*/
#define DEVICE_INIT_DT_GET(node_id) (&Z_INIT_ENTRY_NAME(DEVICE_DT_NAME_GET(node_id)))
/**
* @def DEVICE_INIT_GET
*
* @brief Get a <tt>const struct init_entry*</tt> from a device by name
*
* @param name The same as dev_name provided to DEVICE_DEFINE()
*
* @return A pointer to the init_entry object created for that device
*/
#define DEVICE_INIT_GET(name) (&Z_INIT_ENTRY_NAME(DEVICE_NAME_GET(name)))
/**
* @brief Runtime device dynamic structure (in RAM) per driver instance
*
* Fields in this are expected to be default-initialized to zero. The
* kernel driver infrastructure and driver access functions are
* responsible for ensuring that any non-zero initialization is done
* before they are accessed.
*/
struct device_state {
/** Non-negative result of initializing the device.
*
* The absolute value returned when the device initialization
* function was invoked, or `UINT8_MAX` if the value exceeds
* an 8-bit integer. If initialized is also set, a zero value
* indicates initialization succeeded.
*/
unsigned int init_res : 8;
/** Indicates the device initialization function has been
* invoked.
*/
bool initialized : 1;
};
struct pm_device;
#ifdef CONFIG_HAS_DYNAMIC_DEVICE_HANDLES
#define Z_DEVICE_HANDLES_CONST
#else
#define Z_DEVICE_HANDLES_CONST const
#endif
/**
* @brief Runtime device structure (in ROM) per driver instance
*/
struct device {
/** Name of the device instance */
const char *name;
/** Address of device instance config information */
const void *config;
/** Address of the API structure exposed by the device instance */
const void *api;
/** Address of the common device state */
struct device_state *state;
/** Address of the device instance private data */
void *data;
/** optional pointer to handles associated with the device.
*
* This encodes a sequence of sets of device handles that have
* some relationship to this node. The individual sets are
* extracted with dedicated API, such as
* device_required_handles_get().
*/
Z_DEVICE_HANDLES_CONST device_handle_t *handles;
#ifdef CONFIG_PM_DEVICE
/** Reference to the device PM resources. */
struct pm_device *pm;
#endif
};
/**
* @brief Get the handle for a given device
*
* @param dev the device for which a handle is desired.
*
* @return the handle for the device, or DEVICE_HANDLE_NULL if the
* device does not have an associated handle.
*/
static inline device_handle_t
device_handle_get(const struct device *dev)
{
device_handle_t ret = DEVICE_HANDLE_NULL;
extern const struct device __device_start[];
/* TODO: If/when devices can be constructed that are not part of the
* fixed sequence we'll need another solution.
*/
if (dev != NULL) {
ret = 1 + (device_handle_t)(dev - __device_start);
}
return ret;
}
/**
* @brief Get the device corresponding to a handle.
*
* @param dev_handle the device handle
*
* @return the device that has that handle, or a null pointer if @p
* dev_handle does not identify a device.
*/
static inline const struct device *
device_from_handle(device_handle_t dev_handle)
{
extern const struct device __device_start[];
extern const struct device __device_end[];
const struct device *dev = NULL;
size_t numdev = __device_end - __device_start;
if ((dev_handle > 0) && ((size_t)dev_handle <= numdev)) {
dev = &__device_start[dev_handle - 1];
}
return dev;
}
/**
* @brief Prototype for functions used when iterating over a set of devices.
*
* Such a function may be used in API that identifies a set of devices and
* provides a visitor API supporting caller-specific interaction with each
* device in the set.
*
* The visit is said to succeed if the visitor returns a non-negative value.
*
* @param dev a device in the set being iterated
*
* @param context state used to support the visitor function
*
* @return A non-negative number to allow walking to continue, and a negative
* error code to case the iteration to stop.
*
* @see device_required_foreach()
* @see device_supported_foreach()
*/
typedef int (*device_visitor_callback_t)(const struct device *dev, void *context);
/**
* @brief Get the device handles for devicetree dependencies of this device.
*
* This function returns a pointer to an array of device handles. The
* length of the array is stored in the @p count parameter.
*
* The array contains a handle for each device that @p dev requires
* directly, as determined from the devicetree. This does not include
* transitive dependencies; you must recursively determine those.
*
* @param dev the device for which dependencies are desired.
*
* @param count pointer to where this function should store the length
* of the returned array. No value is stored if the call returns a
* null pointer. The value may be set to zero if the device has no
* devicetree dependencies.
*
* @return a pointer to a sequence of @p *count device handles, or a null
* pointer if @p dev does not have any dependency data.
*/
static inline const device_handle_t *
device_required_handles_get(const struct device *dev,
size_t *count)
{
const device_handle_t *rv = dev->handles;
if (rv != NULL) {
size_t i = 0;
while ((rv[i] != DEVICE_HANDLE_ENDS)
&& (rv[i] != DEVICE_HANDLE_SEP)) {
++i;
}
*count = i;
}
return rv;
}
/**
* @brief Get the device handles for injected dependencies of this device.
*
* This function returns a pointer to an array of device handles. The
* length of the array is stored in the @p count parameter.
*
* The array contains a handle for each device that @p dev manually injected
* as a dependency, via providing extra arguments to Z_DEVICE_DEFINE. This does
* not include transitive dependencies; you must recursively determine those.
*
* @param dev the device for which injected dependencies are desired.
*
* @param count pointer to where this function should store the length
* of the returned array. No value is stored if the call returns a
* null pointer. The value may be set to zero if the device has no
* devicetree dependencies.
*
* @return a pointer to a sequence of @p *count device handles, or a null
* pointer if @p dev does not have any dependency data.
*/
static inline const device_handle_t *
device_injected_handles_get(const struct device *dev,
size_t *count)
{
const device_handle_t *rv = dev->handles;
size_t region = 0;
size_t i = 0;
if (rv != NULL) {
/* Fast forward to injected devices */
while (region != 1) {
if (*rv == DEVICE_HANDLE_SEP) {
region++;
}
rv++;
}
while ((rv[i] != DEVICE_HANDLE_ENDS)
&& (rv[i] != DEVICE_HANDLE_SEP)) {
++i;
}
*count = i;
}
return rv;
}
/**
* @brief Get the set of handles that this device supports.
*
* This function returns a pointer to an array of device handles. The
* length of the array is stored in the @p count parameter.
*
* The array contains a handle for each device that @p dev "supports"
* -- that is, devices that require @p dev directly -- as determined
* from the devicetree. This does not include transitive dependencies;
* you must recursively determine those.
*
* @param dev the device for which supports are desired.
*
* @param count pointer to where this function should store the length
* of the returned array. No value is stored if the call returns a
* null pointer. The value may be set to zero if nothing in the
* devicetree depends on @p dev.
*
* @return a pointer to a sequence of @p *count device handles, or a null
* pointer if @p dev does not have any dependency data.
*/
static inline const device_handle_t *
device_supported_handles_get(const struct device *dev,
size_t *count)
{
const device_handle_t *rv = dev->handles;
size_t region = 0;
size_t i = 0;
if (rv != NULL) {
/* Fast forward to supporting devices */
while (region != 2) {
if (*rv == DEVICE_HANDLE_SEP) {
region++;
}
rv++;
}
/* Count supporting devices */
while (rv[i] != DEVICE_HANDLE_ENDS) {
++i;
}
*count = i;
}
return rv;
}
/**
* @brief Visit every device that @p dev directly requires.
*
* Zephyr maintains information about which devices are directly required by
* another device; for example an I2C-based sensor driver will require an I2C
* controller for communication. Required devices can derive from
* statically-defined devicetree relationships or dependencies registered
* at runtime.
*
* This API supports operating on the set of required devices. Example uses
* include making sure required devices are ready before the requiring device
* is used, and releasing them when the requiring device is no longer needed.
*
* There is no guarantee on the order in which required devices are visited.
*
* If the @p visitor function returns a negative value iteration is halted,
* and the returned value from the visitor is returned from this function.
*
* @note This API is not available to unprivileged threads.
*
* @param dev a device of interest. The devices that this device depends on
* will be used as the set of devices to visit. This parameter must not be
* null.
*
* @param visitor_cb the function that should be invoked on each device in the
* dependency set. This parameter must not be null.
*
* @param context state that is passed through to the visitor function. This
* parameter may be null if @p visitor tolerates a null @p context.
*
* @return The number of devices that were visited if all visits succeed, or
* the negative value returned from the first visit that did not succeed.
*/
int device_required_foreach(const struct device *dev,
device_visitor_callback_t visitor_cb,
void *context);
/**
* @brief Visit every device that @p dev directly supports.
*
* Zephyr maintains information about which devices are directly supported by
* another device; for example an I2C controller will support an I2C-based
* sensor driver. Supported devices can derive from statically-defined
* devicetree relationships.
*
* This API supports operating on the set of supported devices. Example uses
* include iterating over the devices connected to a regulator when it is
* powered on.
*
* There is no guarantee on the order in which required devices are visited.
*
* If the @p visitor function returns a negative value iteration is halted,
* and the returned value from the visitor is returned from this function.
*
* @note This API is not available to unprivileged threads.
*
* @param dev a device of interest. The devices that this device supports
* will be used as the set of devices to visit. This parameter must not be
* null.
*
* @param visitor_cb the function that should be invoked on each device in the
* support set. This parameter must not be null.
*
* @param context state that is passed through to the visitor function. This
* parameter may be null if @p visitor tolerates a null @p context.
*
* @return The number of devices that were visited if all visits succeed, or
* the negative value returned from the first visit that did not succeed.
*/
int device_supported_foreach(const struct device *dev,
device_visitor_callback_t visitor_cb,
void *context);
/**
* @brief Get a <tt>const struct device*</tt> from its @p name field
*
* @details This function iterates through the devices on the system.
* If a device with the given @p name field is found, and that device
* initialized successfully at boot time, this function returns a
* pointer to the device.
*
* If no device has the given name, this function returns NULL.
*
* This function also returns NULL when a device is found, but it
* failed to initialize successfully at boot time. (To troubleshoot
* this case, set a breakpoint on your device driver's initialization
* function.)
*
* @param name device name to search for. A null pointer, or a pointer
* to an empty string, will cause NULL to be returned.
*
* @return pointer to device structure with the given name; NULL if
* the device is not found or if the device with that name's
* initialization function failed.
*/
__syscall const struct device *device_get_binding(const char *name);
/** @brief Get access to the static array of static devices.
*
* @param devices where to store the pointer to the array of
* statically allocated devices. The array must not be mutated
* through this pointer.
*
* @return the number of statically allocated devices.
*/
size_t z_device_get_all_static(const struct device * *devices);
/**
* @brief Verify that a device is ready for use.
*
* This is the implementation underlying device_is_ready(), without the overhead
* of a syscall wrapper.
*
* @param dev pointer to the device in question.
*
* @retval true If the device is ready for use.
* @retval false If the device is not ready for use or if a NULL device pointer
* is passed as argument.
*
* @see device_is_ready()
*/
bool z_device_is_ready(const struct device *dev);
/** @brief Verify that a device is ready for use.
*
* Indicates whether the provided device pointer is for a device known to be
* in a state where it can be used with its standard API.
*
* This can be used with device pointers captured from DEVICE_DT_GET(), which
* does not include the readiness checks of device_get_binding(). At minimum
* this means that the device has been successfully initialized.
*
* @param dev pointer to the device in question.
*
* @retval true If the device is ready for use.
* @retval false If the device is not ready for use or if a NULL device pointer
* is passed as argument.
*/
__syscall bool device_is_ready(const struct device *dev);
static inline bool z_impl_device_is_ready(const struct device *dev)
{
return z_device_is_ready(dev);
}
/**
* @}
*/
/* Synthesize the name of the object that holds device ordinal and
* dependency data. If the object doesn't come from a devicetree
* node, use dev_name.
*/
#define Z_DEVICE_HANDLE_NAME(node_id, dev_name) \
_CONCAT(__devicehdl_, \
COND_CODE_1(DT_NODE_EXISTS(node_id), \
(node_id), \
(dev_name)))
#define Z_DEVICE_EXTRA_HANDLES(...) \
FOR_EACH_NONEMPTY_TERM(IDENTITY, (,), __VA_ARGS__)
/*
* Utility macro to define and initialize the device state.
*
* @param node_id Devicetree node id of the device.
* @param dev_name Device name.
*/
#define Z_DEVICE_STATE_DEFINE(node_id, dev_name) \
static struct device_state Z_DEVICE_STATE_NAME(dev_name) \
__attribute__((__section__(".z_devstate")));
/* Construct objects that are referenced from struct device. These
* include power management and dependency handles.
*/
#define Z_DEVICE_DEFINE_PRE(node_id, dev_name, ...) \
Z_DEVICE_DEFINE_HANDLES(node_id, dev_name, __VA_ARGS__)
/* Initial build provides a record that associates the device object
* with its devicetree ordinal, and provides the dependency ordinals.
* These are provided as weak definitions (to prevent the reference
* from being captured when the original object file is compiled), and
* in a distinct pass1 section (which will be replaced by
* postprocessing).
*
* Before processing in gen_handles.py, the array format is:
* {
* DEVICE_ORDINAL (or DEVICE_HANDLE_NULL if not a devicetree node),
* List of devicetree dependency ordinals (if any),
* DEVICE_HANDLE_SEP,
* List of injected dependency ordinals (if any),
* DEVICE_HANDLE_SEP,
* List of devicetree supporting ordinals (if any),
* }
*
* After processing in gen_handles.py, the format is updated to:
* {
* List of existing devicetree dependency handles (if any),
* DEVICE_HANDLE_SEP,
* List of injected devicetree dependency handles (if any),
* DEVICE_HANDLE_SEP,
* List of existing devicetree support handles (if any),
* DEVICE_HANDLE_NULL
* }
*
* It is also (experimentally) necessary to provide explicit alignment
* on each object. Otherwise x86-64 builds will introduce padding
* between objects in the same input section in individual object
* files, which will be retained in subsequent links both wasting
* space and resulting in aggregate size changes relative to pass2
* when all objects will be in the same input section.
*
* The build assert will fail if device_handle_t changes size, which
* means the alignment directives in the linker scripts and in
* `gen_handles.py` must be updated.
*/
BUILD_ASSERT(sizeof(device_handle_t) == 2, "fix the linker scripts");
#define Z_DEVICE_DEFINE_HANDLES(node_id, dev_name, ...) \
extern Z_DEVICE_HANDLES_CONST device_handle_t \
Z_DEVICE_HANDLE_NAME(node_id, dev_name)[]; \
Z_DEVICE_HANDLES_CONST device_handle_t \
__aligned(sizeof(device_handle_t)) \
__attribute__((__weak__, \
__section__(".__device_handles_pass1"))) \
Z_DEVICE_HANDLE_NAME(node_id, dev_name)[] = { \
COND_CODE_1(DT_NODE_EXISTS(node_id), ( \
DT_DEP_ORD(node_id), \
DT_REQUIRES_DEP_ORDS(node_id) \
), ( \
DEVICE_HANDLE_NULL, \
)) \
DEVICE_HANDLE_SEP, \
Z_DEVICE_EXTRA_HANDLES(__VA_ARGS__) \
DEVICE_HANDLE_SEP, \
COND_CODE_1(DT_NODE_EXISTS(node_id), \
(DT_SUPPORTS_DEP_ORDS(node_id)), ()) \
};
#define Z_DEVICE_DEFINE_INIT(node_id, dev_name) \
.handles = Z_DEVICE_HANDLE_NAME(node_id, dev_name),
/* Like DEVICE_DEFINE but takes a node_id AND a dev_name, and trailing
* dependency handles that come from outside devicetree.
*/
#define Z_DEVICE_DEFINE(node_id, dev_name, drv_name, init_fn, pm_device,\
data_ptr, cfg_ptr, level, prio, api_ptr, state_ptr, ...) \
Z_DEVICE_DEFINE_PRE(node_id, dev_name, __VA_ARGS__) \
COND_CODE_1(DT_NODE_EXISTS(node_id), (), (static)) \
const Z_DECL_ALIGN(struct device) \
DEVICE_NAME_GET(dev_name) __used \
__attribute__((__section__(".z_device_" #level STRINGIFY(prio)"_"))) = { \
.name = drv_name, \
.config = (cfg_ptr), \
.api = (api_ptr), \
.state = (state_ptr), \
.data = (data_ptr), \
COND_CODE_1(CONFIG_PM_DEVICE, (.pm = pm_device,), ()) \
Z_DEVICE_DEFINE_INIT(node_id, dev_name) \
}; \
BUILD_ASSERT(sizeof(Z_STRINGIFY(drv_name)) <= Z_DEVICE_MAX_NAME_LEN, \
Z_STRINGIFY(DEVICE_NAME_GET(drv_name)) " too long"); \
Z_INIT_ENTRY_DEFINE(DEVICE_NAME_GET(dev_name), init_fn, \
(&DEVICE_NAME_GET(dev_name)), level, prio)
#ifdef __cplusplus
}
#endif
/* device_extern is generated based on devicetree nodes */
#include <device_extern.h>
#include <syscalls/device.h>
#endif /* ZEPHYR_INCLUDE_DEVICE_H_ */