On 11:19 Mon 22 Jun , Alessandro Rubini wrote:
From: Alessandro Rubini rubini@unipv.it
This sets CONFIG_SYS_HZ to 1000 as required, and completely rewrites timer code, which is now both correct and much smaller. Unused functions like udelay_masked() have been removed as no driver uses them, even the ones that are not currently active for this board.
Signed-off-by: Alessandro Rubini rubini@unipv.it Acked-by: Andrea Gallo andrea.gallo@stericsson.com
for the record what is its precision now?
cpu/arm926ejs/nomadik/timer.c | 190 +++++++++++----------------------------- include/configs/nhk8815.h | 2 +- 2 files changed, 53 insertions(+), 139 deletions(-)
diff --git a/cpu/arm926ejs/nomadik/timer.c b/cpu/arm926ejs/nomadik/timer.c index 2870d24..3618c4a 100644 --- a/cpu/arm926ejs/nomadik/timer.c +++ b/cpu/arm926ejs/nomadik/timer.c @@ -1,20 +1,5 @@ /*
- (C) Copyright 2003
- Texas Instruments <www.ti.com>
- (C) Copyright 2002
- Sysgo Real-Time Solutions, GmbH <www.elinos.com>
- Marius Groeger mgroeger@sysgo.de
- (C) Copyright 2002
- Sysgo Real-Time Solutions, GmbH <www.elinos.com>
- Alex Zuepke azu@sysgo.de
- (C) Copyright 2002-2004
- Gary Jennejohn, DENX Software Engineering, garyj@denx.de
- (C) Copyright 2004
- Philippe Robin, ARM Ltd. philippe.robin@arm.com
- (C) Copyright 2009 Alessandro Rubini
- See file CREDITS for list of people who contributed to this
- project.
@@ -38,145 +23,74 @@ #include <common.h> #include <asm/io.h>
-#define TIMER_LOAD_VAL 0xffffffff +/*
- Registers in the MTU block -- same as <mach/mtu.h> in linux
so please simply import it
+*/
+#define MTU_IMSC 0x00 /* Interrupt mask set/clear */ +#define MTU_RIS 0x04 /* Raw interrupt status */ +#define MTU_MIS 0x08 /* Masked interrupt status */ +#define MTU_ICR 0x0C /* Interrupt clear register */
+/* per-timer registers take 0..3 as argument */ +#define MTU_LR(x) (0x10 + 0x10 * (x) + 0x00) /* Load value */ +#define MTU_VAL(x) (0x10 + 0x10 * (x) + 0x04) /* Current value */ +#define MTU_CR(x) (0x10 + 0x10 * (x) + 0x08) /* Control reg */ +#define MTU_BGLR(x) (0x10 + 0x10 * (x) + 0x0c) /* At next overflow */
+/* bits for the control register */ +#define MTU_CRn_ENA 0x80 +#define MTU_CRn_PERIODIC 0x40 /* if 0 = free-running */ +#define MTU_CRn_PRESCALE_MASK 0x0c +#define MTU_CRn_PRESCALE_1 0x00 +#define MTU_CRn_PRESCALE_16 0x04 +#define MTU_CRn_PRESCALE_256 0x08 +#define MTU_CRn_32BITS 0x02 +#define MTU_CRn_ONESHOT 0x01 /* if 0 = wraps reloading from BGLR*/
-/* macro to read the 32 bit timer */ -#define READ_TIMER readl(CONFIG_SYS_TIMERBASE + 20)
-static ulong timestamp; -static ulong lastdec; +/*
- The timer is a decrementer, we'll left it free running at 2.4MHz.
- We have 2.4 ticks per microsecond and an overflow in almost 30min
- */
+#define TIMER_CLOCK (24*100*1000) +#define COUNT_TO_USEC(x) ((x)*5/12) /* overflows at 6min */
please add space before and after */
+#define USEC_TO_COUNT(x) ((x)*12/5) /* overflows at 6min */ +#define TICKS_PER_HZ (TIMER_CLOCK/CONFIG_SYS_HZ) +#define TICKS_TO_HZ(x) ((x)/TICKS_PER_HZ)
+/* macro to read the 32 bit timer: since it decrements, we invert read value */ +#define READ_TIMER() (~readl(CONFIG_SYS_TIMERBASE + MTU_VAL(0)))
-/* nothing really to do with interrupts, just starts up a counter. */ +/* Configure a free-running, auto-wrap counter with no prescaler */ int timer_init(void) {
- /* Load timer with initial value */
- writel(TIMER_LOAD_VAL, CONFIG_SYS_TIMERBASE + 16);
- /*
* Set timer to be enabled, free-running, no interrupts, 256 divider,* 32-bit, wrap-mode*/- writel(0x8a, CONFIG_SYS_TIMERBASE + 24);
- /* init the timestamp and lastdec value */
- reset_timer_masked();
- writel(MTU_CRn_ENA | MTU_CRn_PRESCALE_1 | MTU_CRn_32BITS,
CONFIG_SYS_TIMERBASE + MTU_CR(0));- reset_timer(); return 0;
}
-/*
- timer without interrupts
- */
+/* Restart counting from 0 */ void reset_timer(void) {
- reset_timer_masked();
- writel(0, CONFIG_SYS_TIMERBASE + MTU_LR(0)); /* Immediate effect */
}
+/* Return how many HZ passed since "base" */ ulong get_timer(ulong base) {
- return get_timer_masked() - base;
-}
-void set_timer(ulong t) -{
- timestamp = t;
- ulong res = TICKS_TO_HZ(READ_TIMER()) - base;
please return directly
- return res;
}
Best Regards, J.