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Diffstat (limited to 'arch/arm/cpu/arm926ejs/armada100/timer.c')
| -rw-r--r-- | arch/arm/cpu/arm926ejs/armada100/timer.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm926ejs/armada100/timer.c b/arch/arm/cpu/arm926ejs/armada100/timer.c new file mode 100644 index 0000000..948607f --- /dev/null +++ b/arch/arm/cpu/arm926ejs/armada100/timer.c @@ -0,0 +1,210 @@ +/* + * (C) Copyright 2010 + * Marvell Semiconductor <www.marvell.com> + * Written-by: Prafulla Wadaskar <prafulla@marvell.com> + * Contributor: Mahavir Jain <mjain@marvell.com> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301 USA + */ + +#include <common.h> +#include <asm/arch/cpu.h> +#include <asm/arch/armada100.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)); +} + +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 (unsigned long ignored) +{ + 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; +} |
