/**************************************************************************** * include/nuttx/timer.h * * Copyright (C) 2014 Gregory Nutt. All rights reserved. * Authors: Gregory Nutt * 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 #include #include #include #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 */