diff options
Diffstat (limited to 'arch/arm/mach-gemini/time.c')
| -rw-r--r-- | arch/arm/mach-gemini/time.c | 97 |
1 files changed, 89 insertions, 8 deletions
diff --git a/arch/arm/mach-gemini/time.c b/arch/arm/mach-gemini/time.c index 21dc5a89d1c4..0a63c4d25b64 100644 --- a/arch/arm/mach-gemini/time.c +++ b/arch/arm/mach-gemini/time.c @@ -13,6 +13,8 @@ #include <mach/hardware.h> #include <mach/global_reg.h> #include <asm/mach/time.h> +#include <linux/clockchips.h> +#include <linux/clocksource.h> /* * Register definitions for the timers @@ -33,19 +35,89 @@ #define TIMER_3_CR_CLOCK (1 << 7) #define TIMER_3_CR_INT (1 << 8) +static unsigned int tick_rate; + +static int gemini_timer_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + u32 cr; + + cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + + /* This may be overdoing it, feel free to test without this */ + cr &= ~TIMER_2_CR_ENABLE; + cr &= ~TIMER_2_CR_INT; + writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + + /* Set next event */ + writel(cycles, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE))); + writel(cycles, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE))); + cr |= TIMER_2_CR_ENABLE; + cr |= TIMER_2_CR_INT; + writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + + return 0; +} + +static void gemini_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + u32 period = DIV_ROUND_CLOSEST(tick_rate, HZ); + u32 cr; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* Start the timer */ + writel(period, + TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE))); + writel(period, + TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE))); + cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + cr |= TIMER_2_CR_ENABLE; + cr |= TIMER_2_CR_INT; + writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + break; + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_RESUME: + /* + * Disable also for oneshot: the set_next() call will + * arm the timer instead. + */ + cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + cr &= ~TIMER_2_CR_ENABLE; + cr &= ~TIMER_2_CR_INT; + writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + break; + default: + break; + } +} + +/* Use TIMER2 as clock event */ +static struct clock_event_device gemini_clockevent = { + .name = "TIMER2", + .rating = 300, /* Reasonably fast and accurate clock event */ + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_next_event = gemini_timer_set_next_event, + .set_mode = gemini_timer_set_mode, +}; + /* * IRQ handler for the timer */ static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id) { - timer_tick(); + struct clock_event_device *evt = &gemini_clockevent; + evt->event_handler(evt); return IRQ_HANDLED; } static struct irqaction gemini_timer_irq = { .name = "Gemini Timer Tick", - .flags = IRQF_DISABLED | IRQF_TIMER, + .flags = IRQF_TIMER, .handler = gemini_timer_interrupt, }; @@ -54,9 +126,9 @@ static struct irqaction gemini_timer_irq = { */ void __init gemini_timer_init(void) { - unsigned int tick_rate, reg_v; + u32 reg_v; - reg_v = __raw_readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS)); + reg_v = readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS)); tick_rate = REG_TO_AHB_SPEED(reg_v) * 1000000; printk(KERN_INFO "Bus: %dMHz", tick_rate / 1000000); @@ -82,8 +154,17 @@ void __init gemini_timer_init(void) * Make irqs happen for the system timer */ setup_irq(IRQ_TIMER2, &gemini_timer_irq); - /* Start the timer */ - __raw_writel(tick_rate / HZ, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE))); - __raw_writel(tick_rate / HZ, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE))); - __raw_writel(TIMER_2_CR_ENABLE | TIMER_2_CR_INT, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + + /* Enable and use TIMER1 as clock source */ + writel(0xffffffff, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER1_BASE))); + writel(0xffffffff, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER1_BASE))); + writel(TIMER_1_CR_ENABLE, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE))); + if (clocksource_mmio_init(TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER1_BASE)), + "TIMER1", tick_rate, 300, 32, + clocksource_mmio_readl_up)) + pr_err("timer: failed to initialize gemini clock source\n"); + + /* Configure and register the clockevent */ + clockevents_config_and_register(&gemini_clockevent, tick_rate, + 1, 0xffffffff); } |