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author | Wolfgang Denk <wd@denx.de> | 2010-04-07 22:06:31 (GMT) |
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committer | Wolfgang Denk <wd@denx.de> | 2010-04-07 22:06:31 (GMT) |
commit | 6a1f7e54c2dd8888dbc118e8de372dec29a0a9c5 (patch) | |
tree | df5b6d67be790d75e60f8fcd97360fc1f179ab0d /cpu/arm920t/ep93xx/timer.c | |
parent | d8bc0a2889700ba063598de6d4e7d135360b537e (diff) | |
parent | b5045cdda556c73e2697cd1d3ea6563315cbf490 (diff) | |
download | u-boot-6a1f7e54c2dd8888dbc118e8de372dec29a0a9c5.tar.xz |
Merge branch 'master' of git://git.denx.de/u-boot-arm
Diffstat (limited to 'cpu/arm920t/ep93xx/timer.c')
-rw-r--r-- | cpu/arm920t/ep93xx/timer.c | 62 |
1 files changed, 29 insertions, 33 deletions
diff --git a/cpu/arm920t/ep93xx/timer.c b/cpu/arm920t/ep93xx/timer.c index 31304b7..4a0ce4d 100644 --- a/cpu/arm920t/ep93xx/timer.c +++ b/cpu/arm920t/ep93xx/timer.c @@ -1,8 +1,7 @@ /* * Cirrus Logic EP93xx timer support. * - * Copyright (C) 2009, 2010 - * Matthias Kaehlcke <matthias@kaehlcke.net> + * Copyright (C) 2009, 2010 Matthias Kaehlcke <matthias@kaehlcke.net> * * Copyright (C) 2004, 2005 * Cory T. Tusar, Videon Central, Inc., <ctusar@videon-central.com> @@ -42,17 +41,9 @@ static struct ep93xx_timer { unsigned long long ticks; - unsigned long last_update; + unsigned long last_read; } timer; -static inline unsigned long clk_to_systicks(unsigned long long clk_ticks) -{ - unsigned long long sys_ticks = (clk_ticks * CONFIG_SYS_HZ); - do_div(sys_ticks, TIMER_FREQ); - - return (unsigned long)sys_ticks; -} - static inline unsigned long long usecs_to_ticks(unsigned long usecs) { unsigned long long ticks = (unsigned long long)usecs * TIMER_FREQ; @@ -61,11 +52,18 @@ static inline unsigned long long usecs_to_ticks(unsigned long usecs) return ticks; } -static inline unsigned long read_timer(void) +static inline void read_timer(void) { - struct timer_regs *timer = (struct timer_regs *)TIMER_BASE; + struct timer_regs *timer_regs = (struct timer_regs *)TIMER_BASE; + const unsigned long now = TIMER_MAX_VAL - readl(&timer_regs->timer3.value); + + if (now >= timer.last_read) + timer.ticks += now - timer.last_read; + else + /* an overflow occurred */ + timer.ticks += TIMER_MAX_VAL - timer.last_read + now; - return TIMER_MAX_VAL - readl(&timer->timer3.value); + timer.last_read = now; } /* @@ -73,17 +71,14 @@ static inline unsigned long read_timer(void) */ unsigned long long get_ticks(void) { - const unsigned long now = read_timer(); + unsigned long long sys_ticks; - if (now >= timer.last_update) - timer.ticks += now - timer.last_update; - else - /* an overflow occurred */ - timer.ticks += TIMER_MAX_VAL - timer.last_update + now; + read_timer(); - timer.last_update = now; + sys_ticks = timer.ticks * CONFIG_SYS_HZ; + do_div(sys_ticks, TIMER_FREQ); - return clk_to_systicks(timer.ticks); + return sys_ticks; } unsigned long get_timer_masked(void) @@ -98,7 +93,7 @@ unsigned long get_timer(unsigned long base) void reset_timer_masked(void) { - timer.last_update = read_timer(); + read_timer(); timer.ticks = 0; } @@ -109,28 +104,29 @@ void reset_timer(void) void __udelay(unsigned long usec) { - /* read the timer and update timer.ticks */ - get_ticks(); + unsigned long long target; + + read_timer(); - const unsigned long long target = timer.ticks + usecs_to_ticks(usec); + target = timer.ticks + usecs_to_ticks(usec); while (timer.ticks < target) - get_ticks(); + read_timer(); } int timer_init(void) { - struct timer_regs *timer = (struct timer_regs *)TIMER_BASE; + struct timer_regs *timer_regs = (struct timer_regs *)TIMER_BASE; - /* use timer 3 with 508KHz and free running */ - writel(TIMER_CLKSEL, &timer->timer3.control); + /* use timer 3 with 508KHz and free running, not enabled now */ + writel(TIMER_CLKSEL, &timer_regs->timer3.control); - /* set initial timer value 3 */ - writel(TIMER_MAX_VAL, &timer->timer3.load); + /* set initial timer value */ + writel(TIMER_MAX_VAL, &timer_regs->timer3.load); /* Enable the timer */ writel(TIMER_ENABLE | TIMER_CLKSEL, - &timer->timer3.control); + &timer_regs->timer3.control); reset_timer_masked(); |