#include <xinu.h>

Include dependency graph for clkinit.c:

Functions
void	clkinit (void)

Variables
uint32	clktime
	起動してからの現在の時間[s] More...

uint32	count1000
	最後のクロックチックからのミリ秒 More...

uint32	preempt
	プリエンプションカウンタ（クロックが一刻みする度に、クロック割り込みハンドラが値を繰り下げる） More...

qid16	sleepq
	スリープ中のプロセスキュー More...

Function Documentation

◆ clkinit()

void clkinit ( void )

Definition at line 15 of file clkinit.c.

References AM335X_TIMER1MS_ADDR, AM335X_TIMER1MS_CLKCTRL_ADDR, AM335X_TIMER1MS_CLKCTRL_EN, AM335X_TIMER1MS_IRQ, AM335X_TIMER1MS_TCLR_AR, AM335X_TIMER1MS_TCLR_ST, AM335X_TIMER1MS_TIER_OVF_IT_ENA, AM335X_TIMER1MS_TIOCP_CFG_SOFTRESET, AM335X_TIMER1MS_TISTAT_RESETDONE, clkhandler(), clktime, count1000, newqueue(), preempt, QUANTUM, set_evec(), sleepq, am335x_timer1ms::tclr, am335x_timer1ms::tier, am335x_timer1ms::tiocp_cfg, am335x_timer1ms::tistat, am335x_timer1ms::tldr, am335x_timer1ms::tnir, am335x_timer1ms::tpir, and am335x_timer1ms::ttgr.

Referenced by sysinit().

 {
     volatile struct am335x_timer1ms *csrptr =
         (volatile struct am335x_timer1ms *)AM335X_TIMER1MS_ADDR;
     /* Pointer to timer CSR in BBoneBlack   */
     volatile uint32 *clkctrl =
         (volatile uint32 *)AM335X_TIMER1MS_CLKCTRL_ADDR;
 
     *clkctrl = AM335X_TIMER1MS_CLKCTRL_EN;
     while ((*clkctrl) != 0x2) /* Do nothing */
         ;
 
     /* Reset the timer module */
 
     csrptr->tiocp_cfg |= AM335X_TIMER1MS_TIOCP_CFG_SOFTRESET;
 
     /* Wait until the reset is complete */
 
     while ((csrptr->tistat & AM335X_TIMER1MS_TISTAT_RESETDONE) == 0)
         /* Do nothing */;
 
     /* Set interrupt vector for clock to invoke clkint */
 
     set_evec(AM335X_TIMER1MS_IRQ, (uint32)clkhandler);
 
     sleepq = newqueue(); /* Allocate a queue to hold the delta  */
                          /*   list of sleeping processes        */
 
     preempt = QUANTUM; /* Set the preemption time       */
 
     clktime = 0; /* Start counting seconds      */
     count1000 = 0;
     /* The following values are calculated for a    */
     /*   timer that generates 1ms tick rate     */
 
     csrptr->tpir = 1000000;
     csrptr->tnir = 0;
     csrptr->tldr = 0xFFFFFFFF - 26000;
 
     /* Set the timer to auto reload */
 
     csrptr->tclr = AM335X_TIMER1MS_TCLR_AR;
 
     /* Start the timer */
 
     csrptr->tclr |= AM335X_TIMER1MS_TCLR_ST;
 
     /* Enable overflow interrupt which will generate */
     /*   an interrupt every 1 ms             */
 
     csrptr->tier = AM335X_TIMER1MS_TIER_OVF_IT_ENA;
 
     /* Kickstart the timer */
 
     csrptr->ttgr = 1;
 
     return;
 }