u-boot/arch/arm/cpu/arm926ejs/armada100/timer.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2010
* Marvell Semiconductor <www.marvell.com>
* Written-by: Prafulla Wadaskar <prafulla@marvell.com>
* Contributor: Mahavir Jain <mjain@marvell.com>
*/
#include <common.h>
#include <cpu_func.h>
#include <init.h>
#include <time.h>
#include <asm/arch/cpu.h>
#include <asm/arch/armada100.h>
#include <asm/global_data.h>
#include <linux/delay.h>
/*
* Timer registers
* Refer Section A.6 in Datasheet
*/
struct armd1tmr_registers {
u32 clk_ctrl; /* Timer clk control reg */
u32 match[9]; /* Timer match registers */
u32 count[3]; /* Timer count registers */
u32 status[3];
u32 ie[3];
u32 preload[3]; /* Timer preload value */
u32 preload_ctrl[3];
u32 wdt_match_en;
u32 wdt_match_r;
u32 wdt_val;
u32 wdt_sts;
u32 icr[3];
u32 wdt_icr;
u32 cer; /* Timer count enable reg */
u32 cmr;
u32 ilr[3];
u32 wcr;
u32 wfar;
u32 wsar;
u32 cvwr;
};
#define TIMER 0 /* Use TIMER 0 */
/* Each timer has 3 match registers */
#define MATCH_CMP(x) ((3 * TIMER) + x)
#define TIMER_LOAD_VAL 0xffffffff
#define COUNT_RD_REQ 0x1
DECLARE_GLOBAL_DATA_PTR;
/* Using gd->arch.tbu from timestamp and gd->arch.tbl for lastdec */
/* For preventing risk of instability in reading counter value,
* first set read request to register cvwr and then read same
* register after it captures counter value.
*/
ulong read_timer(void)
{
struct armd1tmr_registers *armd1timers =
(struct armd1tmr_registers *) ARMD1_TIMER_BASE;
volatile int loop=100;
writel(COUNT_RD_REQ, &armd1timers->cvwr);
while (loop--);
return(readl(&armd1timers->cvwr));
}
static ulong get_timer_masked(void)
{
ulong now = read_timer();
if (now >= gd->arch.tbl) {
/* normal mode */
gd->arch.tbu += now - gd->arch.tbl;
} else {
/* we have an overflow ... */
gd->arch.tbu += now + TIMER_LOAD_VAL - gd->arch.tbl;
}
gd->arch.tbl = now;
return gd->arch.tbu;
}
ulong get_timer(ulong base)
{
return ((get_timer_masked() / (CONFIG_SYS_HZ_CLOCK / 1000)) -
base);
}
void __udelay(unsigned long usec)
{
ulong delayticks;
ulong endtime;
delayticks = (usec * (CONFIG_SYS_HZ_CLOCK / 1000000));
endtime = get_timer_masked() + delayticks;
while (get_timer_masked() < endtime);
}
/*
* init the Timer
*/
int timer_init(void)
{
struct armd1apb1_registers *apb1clkres =
(struct armd1apb1_registers *) ARMD1_APBC1_BASE;
struct armd1tmr_registers *armd1timers =
(struct armd1tmr_registers *) ARMD1_TIMER_BASE;
/* Enable Timer clock at 3.25 MHZ */
writel(APBC_APBCLK | APBC_FNCLK | APBC_FNCLKSEL(3), &apb1clkres->timers);
/* load value into timer */
writel(0x0, &armd1timers->clk_ctrl);
/* Use Timer 0 Match Resiger 0 */
writel(TIMER_LOAD_VAL, &armd1timers->match[MATCH_CMP(0)]);
/* Preload value is 0 */
writel(0x0, &armd1timers->preload[TIMER]);
/* Enable match comparator 0 for Timer 0 */
writel(0x1, &armd1timers->preload_ctrl[TIMER]);
/* Enable timer 0 */
writel(0x1, &armd1timers->cer);
/* init the gd->arch.tbu and gd->arch.tbl value */
gd->arch.tbl = read_timer();
gd->arch.tbu = 0;
return 0;
}
#define MPMU_APRR_WDTR (1<<4)
#define TMR_WFAR 0xbaba /* WDT Register First key */
#define TMP_WSAR 0xeb10 /* WDT Register Second key */
/*
* This function uses internal Watchdog Timer
* based reset mechanism.
* Steps to write watchdog registers (protected access)
* 1. Write key value to TMR_WFAR reg.
* 2. Write key value to TMP_WSAR reg.
* 3. Perform write operation.
*/
void reset_cpu(void)
{
struct armd1mpmu_registers *mpmu =
(struct armd1mpmu_registers *) ARMD1_MPMU_BASE;
struct armd1tmr_registers *armd1timers =
(struct armd1tmr_registers *) ARMD1_TIMER_BASE;
u32 val;
/* negate hardware reset to the WDT after system reset */
val = readl(&mpmu->aprr);
val = val | MPMU_APRR_WDTR;
writel(val, &mpmu->aprr);
/* reset/enable WDT clock */
writel(APBC_APBCLK | APBC_FNCLK | APBC_RST, &mpmu->wdtpcr);
readl(&mpmu->wdtpcr);
writel(APBC_APBCLK | APBC_FNCLK, &mpmu->wdtpcr);
readl(&mpmu->wdtpcr);
/* clear previous WDT status */
writel(TMR_WFAR, &armd1timers->wfar);
writel(TMP_WSAR, &armd1timers->wsar);
writel(0, &armd1timers->wdt_sts);
/* set match counter */
writel(TMR_WFAR, &armd1timers->wfar);
writel(TMP_WSAR, &armd1timers->wsar);
writel(0xf, &armd1timers->wdt_match_r);
/* enable WDT reset */
writel(TMR_WFAR, &armd1timers->wfar);
writel(TMP_WSAR, &armd1timers->wsar);
writel(0x3, &armd1timers->wdt_match_en);
while(1);
}
/*
* This function is derived from PowerPC code (read timebase as long long).
* On ARM it just returns the timer value.
*/
unsigned long long get_ticks(void)
{
return get_timer(0);
}
/*
* This function is derived from PowerPC code (timebase clock frequency).
* On ARM it returns the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
return (ulong)CONFIG_SYS_HZ;
}