/****************************************************************************
* include/nuttx/timer.h
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Authors: Gregory Nutt <gnutt@nuttx.org>
* Bob Doiron
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_TIMER_H
#define __INCLUDE_NUTTX_TIMER_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <nuttx/irq.h>
#include <nuttx/fs/ioctl.h>
#ifdef CONFIG_TIMER
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* IOCTL Commands ***********************************************************/
/* The timer driver uses a standard character driver framework. However,
* since the timer driver is a device control interface and not a data
* transfer interface, the majority of the functionality is implemented in
* driver ioctl calls. The timer ioctl commands are listed below:
*
* These are detected and handled by the "upper half" timer driver.
*
* TCIOC_START - Start the timer
* Argument: Ignored
* TCIOC_STOP - Stop the timer
* Argument: Ignored
* TCIOC_GETSTATUS - Get the status of the timer.
* Argument: A writeable pointer to struct timer_status_s.
* TCIOC_SETTIMEOUT - Reset the timer timeout to this value
* Argument: A 32-bit timeout value in microseconds.
* TCIOC_SETHANDLER - Call this handler on timer expiration
* Argument: A pointer to struct timer_sethandler_s.
*
* WARNING: May change TCIOC_SETTIMEOUT to pass pointer to 64bit nanoseconds
* or timespec structure.
*
* NOTE: The TCIOC_SETHANDLER ioctl cannot be supported in the kernel build
* mode. In that case direct callbacks from kernel space into user space is
* forbidden.
*/
#define TCIOC_START _TCIOC(0x001)
#define TCIOC_STOP _TCIOC(0x002)
#define TCIOC_GETSTATUS _TCIOC(0x003)
#define TCIOC_SETTIMEOUT _TCIOC(0x004)
#define TCIOC_SETHANDLER _TCIOC(0x005)
/* Bit Settings *************************************************************/
/* Bit settings for the struct timer_status_s flags field */
#define TCFLAGS_ACTIVE (1 << 0) /* 1=The timer is running */
#define TCFLAGS_HANDLER (1 << 1) /* 1=Call the user function when the
* timer expires */
/****************************************************************************
* Public Types
****************************************************************************/
/* User function prototype. Returns true to reload the timer, and the
* function can modify the next interval if desired.
*/
typedef bool (*tccb_t)(FAR uint32_t *next_interval_us);
/* This is the type of the argument passed to the TCIOC_SETHANDLER ioctl */
struct timer_sethandler_s
{
CODE tccb_t newhandler; /* The new timer interrupt handler */
CODE tccb_t oldhandler; /* The previous timer interrupt handler (if any) */
};
/* This is the type of the argument passed to the TCIOC_GETSTATUS ioctl and
* and returned by the "lower half" getstatus() method.
*/
struct timer_status_s
{
uint32_t flags; /* See TCFLAGS_* definitions above */
uint32_t timeout; /* The current timeout setting (in microseconds) */
uint32_t timeleft; /* Time left until the timer expiration
* (in microseconds) */
};
/* This structure provides the "lower-half" driver operations available to
* the "upper-half" driver.
*/
struct timer_lowerhalf_s;
struct timer_ops_s
{
/* Required methods ********************************************************/
/* Start the timer, resetting the time to the current timeout */
CODE int (*start)(FAR struct timer_lowerhalf_s *lower);
/* Stop the timer */
CODE int (*stop)(FAR struct timer_lowerhalf_s *lower);
/* Get the current timer status */
CODE int (*getstatus)(FAR struct timer_lowerhalf_s *lower,
FAR struct timer_status_s *status);
/* Set a new timeout value (and reset the timer) */
CODE int (*settimeout)(FAR struct timer_lowerhalf_s *lower,
uint32_t timeout);
/* Call this user provider timeout handler on timeout.
* NOTE: Providing handler==NULL disable.
*/
CODE tccb_t (*sethandler)(FAR struct timer_lowerhalf_s *lower,
CODE tccb_t handler);
/* Any ioctl commands that are not recognized by the "upper-half" driver
* are forwarded to the lower half driver through this method.
*/
CODE int (*ioctl)(FAR struct timer_lowerhalf_s *lower, int cmd,
unsigned long arg);
};
/* This structure provides the publicly visible representation of the
* "lower-half" driver state structure. "lower half" drivers will have an
* internal structure definition that will be cast-compatible with this
* structure definitions.
*/
struct timer_lowerhalf_s
{
/* Publicly visible portion of the "lower-half" driver state structure. */
FAR const struct timer_ops_s *ops; /* Lower half operations */
/* The remainder of the structure is used by the "lower-half" driver
* for whatever state storage that it may need.
*/
};
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* "Upper-Half" Timer Driver Interfaces
****************************************************************************/
/****************************************************************************
* Name: timer_register
*
* Description:
* This function binds an instance of a "lower half" timer driver with the
* "upper half" timer device and registers that device so that can be used
* by application code.
*
* When this function is called, the "lower half" driver should be in the
* disabled state (as if the stop() method had already been called).
*
* NOTE: Normally, this function would not be called by application code.
* Rather it is called indirectly through the architecture-specific
* initialization.
*
* Input parameters:
* dev path - The full path to the driver to be registers in the NuttX
* pseudo-filesystem. The recommended convention is to name all timer
* drivers as "/dev/timer0", "/dev/timer1", etc. where the driver
* path differs only in the "minor" number at the end of the device name.
* lower - A pointer to an instance of lower half timer driver. This
* instance is bound to the timer driver and must persists as long as
* the driver persists.
*
* Returned Value:
* On success, a non-NULL handle is returned to the caller. In the event
* of any failure, a NULL value is returned.
*
****************************************************************************/
FAR void *timer_register(FAR const char *path,
FAR struct timer_lowerhalf_s *lower);
/****************************************************************************
* Name: timer_unregister
*
* Description:
* This function can be called to disable and unregister the timer
* device driver.
*
* Input parameters:
* handle - This is the handle that was returned by timer_register()
*
* Returned Value:
* None
*
****************************************************************************/
void timer_unregister(FAR void *handle);
/****************************************************************************
* Platform-Independent "Lower-Half" Timer Driver Interfaces
****************************************************************************/
/****************************************************************************
* Architecture-specific Application Interfaces
****************************************************************************/
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_TIMER */
#endif /* __INCLUDE_NUTTX_TIMER_H */
