diff options
author | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2009-05-12 18:53:10 +0000 |
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committer | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2009-05-12 18:53:10 +0000 |
commit | 8320444101b3c5add0466ccc2f38d459fbf5a27f (patch) | |
tree | f4dbc9257abb952de85fed9e3400bb48972e7717 /nuttx/arch/arm/src/lm3s/lm3s_timerisr.c | |
parent | 8d7ea393207b97bfa49dc5b79f35b3b1c02256d2 (diff) |
Add lm3s6918 system timer logic
git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@1773 7fd9a85b-ad96-42d3-883c-3090e2eb8679
Diffstat (limited to 'nuttx/arch/arm/src/lm3s/lm3s_timerisr.c')
-rw-r--r-- | nuttx/arch/arm/src/lm3s/lm3s_timerisr.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/lm3s/lm3s_timerisr.c b/nuttx/arch/arm/src/lm3s/lm3s_timerisr.c new file mode 100644 index 0000000000..e4950d0424 --- /dev/null +++ b/nuttx/arch/arm/src/lm3s/lm3s_timerisr.c @@ -0,0 +1,140 @@ +/**************************************************************************** + * arch/arm/src/lm3s/lm3s_timerisr.c + * + * Copyright (C) 2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> +#include <sys/types.h> +#include <time.h> +#include <debug.h> +#include <nuttx/arch.h> +#include <arch/board/board.h> + +#include "clock_internal.h" +#include "up_internal.h" +#include "up_arch.h" + +#include "chip.h" + +/**************************************************************************** + * Definitions + ****************************************************************************/ + +/* The desired timer interrupt frequency is provided by the definition + * CLK_TCK (see include/time.h). CLK_TCK defines the desired number of + * system clock ticks per second. That value is a user configurable setting + * that defaults to 100 (100 ticks per second = 10 MS interval). + * + * The timer counts at the rate SYSCLK_FREQUENCY as defined in the board.h + * header file. + */ + +#define SYSTICK_RELOAD ((SYSCLK_FREQUENCY / CLK_TCK) - 1) + +/* The size of the reload field is 24 bits. Verify taht the reload value + * will fit in the reload register. + */ + +#if SYSTICK_RELOAD > 0x00ffffff +# error SYSTICK_RELOAD exceeds the range of the RELOAD register +#endif + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Global Functions + ****************************************************************************/ + +/**************************************************************************** + * Function: up_timerisr + * + * Description: + * The timer ISR will perform a variety of services for various portions + * of the systems. + * + ****************************************************************************/ + +int up_timerisr(int irq, uint32 *regs) +{ + /* Process timer interrupt */ + + sched_process_timer(); + return 0; +} + +/**************************************************************************** + * Function: up_timerinit + * + * Description: + * This function is called during start-up to initialize + * the timer interrupt. + * + ****************************************************************************/ + +void up_timerinit(void) +{ + uint32 regval; + + /* Set the SysTick interrupt to the default priority */ + + regval = getreg32(NVIC_SYSH12_15_PRIORITY); + regval &= ~NVIC_SYSH_PRIORITY_PR15_MASK; + regval |= (NVIC_SYSH_PRIORITY_DEFAULT << NVIC_SYSH_PRIORITY_PR15_SHIFT); + putreg32(regval, NVIC_SYSH12_15_PRIORITY); + + /* Configure SysTick to interrupt at the requested rate */ + + putreg32(SYSTICK_RELOAD, NVIC_SYSTICK_RELOAD); + + /* Attach the timer interrupt vector */ + + (void)irq_attach(LMSB_IRQ_SYSTICK, (xcpt_t)up_timerisr); + + /* Enable SysTick interrupts */ + + putreg32((NVIC_SYSTICK_CTRL_CLKSOURCE|NVIC_SYSTICK_CTRL_TICKINT|NVIC_SYSTICK_CTRL_ENABLE), NVIC_SYSTICK_CTRL); + + /* And enable the timer interrupt */ + + up_enable_irq(LMSB_IRQ_SYSTICK); +} |