diff options
Diffstat (limited to 'arch/arm/mach-ks8695/time.c')
| -rw-r--r-- | arch/arm/mach-ks8695/time.c | 127 |
1 files changed, 87 insertions, 40 deletions
diff --git a/arch/arm/mach-ks8695/time.c b/arch/arm/mach-ks8695/time.c index ec783a3070a..46c84bc7792 100644 --- a/arch/arm/mach-ks8695/time.c +++ b/arch/arm/mach-ks8695/time.c @@ -25,53 +25,98 @@ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/io.h> +#include <linux/clockchips.h> #include <asm/mach/time.h> #include <asm/system_misc.h> -#include <mach/regs-timer.h> #include <mach/regs-irq.h> #include "generic.h" +#define KS8695_TMR_OFFSET (0xF0000 + 0xE400) +#define KS8695_TMR_VA (KS8695_IO_VA + KS8695_TMR_OFFSET) +#define KS8695_TMR_PA (KS8695_IO_PA + KS8695_TMR_OFFSET) + /* - * Returns number of ms since last clock interrupt. Note that interrupts - * will have been disabled by do_gettimeoffset() + * Timer registers */ -static unsigned long ks8695_gettimeoffset (void) +#define KS8695_TMCON (0x00) /* Timer Control Register */ +#define KS8695_T1TC (0x04) /* Timer 1 Timeout Count Register */ +#define KS8695_T0TC (0x08) /* Timer 0 Timeout Count Register */ +#define KS8695_T1PD (0x0C) /* Timer 1 Pulse Count Register */ +#define KS8695_T0PD (0x10) /* Timer 0 Pulse Count Register */ + +/* Timer Control Register */ +#define TMCON_T1EN (1 << 1) /* Timer 1 Enable */ +#define TMCON_T0EN (1 << 0) /* Timer 0 Enable */ + +/* Timer0 Timeout Counter Register */ +#define T0TC_WATCHDOG (0xff) /* Enable watchdog mode */ + +static void ks8695_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) { - unsigned long elapsed, tick2, intpending; + u32 tmcon; - /* - * Get the current number of ticks. Note that there is a race - * condition between us reading the timer and checking for an - * interrupt. We solve this by ensuring that the counter has not - * reloaded between our two reads. - */ - elapsed = __raw_readl(KS8695_TMR_VA + KS8695_T1TC) + __raw_readl(KS8695_TMR_VA + KS8695_T1PD); - do { - tick2 = elapsed; - intpending = __raw_readl(KS8695_IRQ_VA + KS8695_INTST) & (1 << KS8695_IRQ_TIMER1); - elapsed = __raw_readl(KS8695_TMR_VA + KS8695_T1TC) + __raw_readl(KS8695_TMR_VA + KS8695_T1PD); - } while (elapsed > tick2); + if (mode == CLOCK_EVT_FEAT_PERIODIC) { + u32 rate = DIV_ROUND_CLOSEST(KS8695_CLOCK_RATE, HZ); + u32 half = DIV_ROUND_CLOSEST(rate, 2); + + /* Disable timer 1 */ + tmcon = readl_relaxed(KS8695_TMR_VA + KS8695_TMCON); + tmcon &= ~TMCON_T1EN; + writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON); + + /* Both registers need to count down */ + writel_relaxed(half, KS8695_TMR_VA + KS8695_T1TC); + writel_relaxed(half, KS8695_TMR_VA + KS8695_T1PD); + + /* Re-enable timer1 */ + tmcon |= TMCON_T1EN; + writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON); + } +} - /* Convert to number of ticks expired (not remaining) */ - elapsed = (CLOCK_TICK_RATE / HZ) - elapsed; +static int ks8695_set_next_event(unsigned long cycles, + struct clock_event_device *evt) - /* Is interrupt pending? If so, then timer has been reloaded already. */ - if (intpending) - elapsed += (CLOCK_TICK_RATE / HZ); +{ + u32 half = DIV_ROUND_CLOSEST(cycles, 2); + u32 tmcon; + + /* Disable timer 1 */ + tmcon = readl_relaxed(KS8695_TMR_VA + KS8695_TMCON); + tmcon &= ~TMCON_T1EN; + writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON); + + /* Both registers need to count down */ + writel_relaxed(half, KS8695_TMR_VA + KS8695_T1TC); + writel_relaxed(half, KS8695_TMR_VA + KS8695_T1PD); - /* Convert ticks to usecs */ - return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH; + /* Re-enable timer1 */ + tmcon |= TMCON_T1EN; + writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON); + + return 0; } +static struct clock_event_device clockevent_ks8695 = { + .name = "ks8695_t1tc", + .rating = 300, /* Reasonably fast and accurate clock event */ + .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, + .set_next_event = ks8695_set_next_event, + .set_mode = ks8695_set_mode, +}; + /* * IRQ handler for the timer. */ static irqreturn_t ks8695_timer_interrupt(int irq, void *dev_id) { - timer_tick(); + struct clock_event_device *evt = &clockevent_ks8695; + + evt->event_handler(evt); return IRQ_HANDLED; } @@ -83,18 +128,22 @@ static struct irqaction ks8695_timer_irq = { static void ks8695_timer_setup(void) { - unsigned long tmout = CLOCK_TICK_RATE / HZ; unsigned long tmcon; - /* disable timer1 */ - tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); - __raw_writel(tmcon & ~TMCON_T1EN, KS8695_TMR_VA + KS8695_TMCON); - - __raw_writel(tmout / 2, KS8695_TMR_VA + KS8695_T1TC); - __raw_writel(tmout / 2, KS8695_TMR_VA + KS8695_T1PD); + /* Disable timer 0 and 1 */ + tmcon = readl_relaxed(KS8695_TMR_VA + KS8695_TMCON); + tmcon &= ~TMCON_T0EN; + tmcon &= ~TMCON_T1EN; + writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON); - /* re-enable timer1 */ - __raw_writel(tmcon | TMCON_T1EN, KS8695_TMR_VA + KS8695_TMCON); + /* + * Use timer 1 to fire IRQs on the timeline, minimum 2 cycles + * (one on each counter) maximum 2*2^32, but the API will only + * accept up to a 32bit full word (0xFFFFFFFFU). + */ + clockevents_config_and_register(&clockevent_ks8695, + KS8695_CLOCK_RATE, 2, + 0xFFFFFFFFU); } static void __init ks8695_timer_init (void) @@ -107,8 +156,6 @@ static void __init ks8695_timer_init (void) struct sys_timer ks8695_timer = { .init = ks8695_timer_init, - .offset = ks8695_gettimeoffset, - .resume = ks8695_timer_setup, }; void ks8695_restart(char mode, const char *cmd) @@ -119,12 +166,12 @@ void ks8695_restart(char mode, const char *cmd) soft_restart(0); /* disable timer0 */ - reg = __raw_readl(KS8695_TMR_VA + KS8695_TMCON); - __raw_writel(reg & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); + reg = readl_relaxed(KS8695_TMR_VA + KS8695_TMCON); + writel_relaxed(reg & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); /* enable watchdog mode */ - __raw_writel((10 << 8) | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC); + writel_relaxed((10 << 8) | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC); /* re-enable timer0 */ - __raw_writel(reg | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); + writel_relaxed(reg | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON); } |