diff options
Diffstat (limited to 'cpu/arm1136/mx35/timer.c')
-rw-r--r-- | cpu/arm1136/mx35/timer.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/cpu/arm1136/mx35/timer.c b/cpu/arm1136/mx35/timer.c new file mode 100644 index 0000000..d6f65cf --- /dev/null +++ b/cpu/arm1136/mx35/timer.c @@ -0,0 +1,127 @@ +/* + * (C) Copyright 2007 + * Sascha Hauer, Pengutronix + * + * (C) Copyright 2008-2009 Freescale Semiconductor, Inc. + * + * 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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/arch/mx35.h> + +/* General purpose timers registers */ +#define GPTCR __REG(GPT1_BASE_ADDR) /* Control register */ +#define GPTPR __REG(GPT1_BASE_ADDR + 0x4) /* Prescaler register */ +#define GPTSR __REG(GPT1_BASE_ADDR + 0x8) /* Status register */ +#define GPTCNT __REG(GPT1_BASE_ADDR + 0x24) /* Counter register */ + +/* General purpose timers bitfields */ +#define GPTCR_SWR (1<<15) /* Software reset */ +#define GPTCR_FRR (1<<9) /* Freerun / restart */ +#define GPTCR_CLKSOURCE_32 (4<<6) /* Clock source */ +#define GPTCR_TEN (1) /* Timer enable */ + +static inline void setup_gpt() +{ + int i; + static int init_done; + + if (init_done) + return; + + init_done = 1; + + /* setup GP Timer 1 */ + GPTCR = GPTCR_SWR; + for (i = 0; i < 100; i++) + GPTCR = 0; /* We have no udelay by now */ + GPTPR = 0; /* 32Khz */ + /* Freerun Mode, PERCLK1 input */ + GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN; +} + +int timer_init(void) +{ + setup_gpt(); + + return 0; +} + +void reset_timer(void) +{ + reset_timer_masked(); +} + +void reset_timer_masked(void) +{ + GPTCR = 0; + /* Freerun Mode, PERCLK1 input */ + GPTCR = GPTCR_CLKSOURCE_32 | GPTCR_TEN; +} + +ulong get_timer_masked(void) +{ + ulong val = GPTCNT; + return val; +} + +ulong get_timer(ulong base) +{ + return get_timer_masked() - base; +} + +void set_timer(ulong t) +{ +} + +/* delay x useconds AND perserve advance timstamp value */ +void udelay(unsigned long usec) +{ + ulong tmo, tmp; + + setup_gpt(); + + /* if "big" number, spread normalization to seconds */ + if (usec >= 1000) { + /* start to normalize for usec to ticks per sec */ + tmo = usec / 1000; + /* find number of "ticks" to wait to achieve target */ + tmo *= CONFIG_SYS_HZ; + tmo /= 1000; /* finish normalize. */ + } else {/* else small number, don't kill it prior to HZ multiply */ + tmo = usec * CONFIG_SYS_HZ; + tmo /= (1000 * 1000); + } + + tmp = get_timer(0); /* get current timestamp */ + /* if setting this forward will roll time stamp */ + if ((tmo + tmp + 1) < tmp) + /* reset "advancing" timestamp to 0, set lastinc value */ + reset_timer_masked(); + else /* else, set advancing stamp wake up time */ + tmo += tmp; + while (get_timer_masked() < tmo) /* loop till event */ + /*NOP*/; +} + +void reset_cpu(ulong addr) +{ + __REG16(WDOG_BASE_ADDR) = 4; +} |