diff options
Diffstat (limited to 'arch/arm/cpu/arm926ejs/spear/timer.c')
-rw-r--r-- | arch/arm/cpu/arm926ejs/spear/timer.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm926ejs/spear/timer.c b/arch/arm/cpu/arm926ejs/spear/timer.c new file mode 100644 index 0000000..06858b4 --- /dev/null +++ b/arch/arm/cpu/arm926ejs/spear/timer.c @@ -0,0 +1,153 @@ +/* + * (C) Copyright 2009 + * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/arch/hardware.h> +#include <asm/arch/spr_gpt.h> +#include <asm/arch/spr_misc.h> + +#define GPT_RESOLUTION (CONFIG_SPEAR_HZ_CLOCK / CONFIG_SPEAR_HZ) +#define READ_TIMER() (readl(&gpt_regs_p->count) & GPT_FREE_RUNNING) + +static struct gpt_regs *const gpt_regs_p = + (struct gpt_regs *)CONFIG_SPEAR_TIMERBASE; + +static struct misc_regs *const misc_regs_p = + (struct misc_regs *)CONFIG_SPEAR_MISCBASE; + +static ulong timestamp; +static ulong lastdec; + +int timer_init(void) +{ + u32 synth; + + /* Prescaler setting */ +#if defined(CONFIG_SPEAR3XX) + writel(MISC_PRSC_CFG, &misc_regs_p->prsc2_clk_cfg); + synth = MISC_GPT4SYNTH; +#elif defined(CONFIG_SPEAR600) + writel(MISC_PRSC_CFG, &misc_regs_p->prsc1_clk_cfg); + synth = MISC_GPT3SYNTH; +#else +# error Incorrect config. Can only be spear{600|300|310|320} +#endif + + writel(readl(&misc_regs_p->periph_clk_cfg) | synth, + &misc_regs_p->periph_clk_cfg); + + /* disable timers */ + writel(GPT_PRESCALER_1 | GPT_MODE_AUTO_RELOAD, &gpt_regs_p->control); + + /* load value for free running */ + writel(GPT_FREE_RUNNING, &gpt_regs_p->compare); + + /* auto reload, start timer */ + writel(readl(&gpt_regs_p->control) | GPT_ENABLE, &gpt_regs_p->control); + + reset_timer_masked(); + + return 0; +} + +/* + * timer without interrupts + */ + +void reset_timer(void) +{ + reset_timer_masked(); +} + +ulong get_timer(ulong base) +{ + return (get_timer_masked() / GPT_RESOLUTION) - base; +} + +void set_timer(ulong t) +{ + timestamp = t; +} + +void __udelay(unsigned long usec) +{ + ulong tmo; + ulong start = get_timer_masked(); + ulong tenudelcnt = CONFIG_SPEAR_HZ_CLOCK / (1000 * 100); + ulong rndoff; + + rndoff = (usec % 10) ? 1 : 0; + + /* tenudelcnt timer tick gives 10 microsecconds delay */ + tmo = ((usec / 10) + rndoff) * tenudelcnt; + + while ((ulong) (get_timer_masked() - start) < tmo) + ; +} + +void reset_timer_masked(void) +{ + /* reset time */ + lastdec = READ_TIMER(); + timestamp = 0; +} + +ulong get_timer_masked(void) +{ + ulong now = READ_TIMER(); + + if (now >= lastdec) { + /* normal mode */ + timestamp += now - lastdec; + } else { + /* we have an overflow ... */ + timestamp += now + GPT_FREE_RUNNING - lastdec; + } + lastdec = now; + + return timestamp; +} + +void udelay_masked(unsigned long usec) +{ + return udelay(usec); +} + +/* + * 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 CONFIG_SPEAR_HZ; +} |