diff options
Diffstat (limited to 'arch/arm/plat-aspeed/timer.c')
| -rw-r--r-- | arch/arm/plat-aspeed/timer.c | 223 |
1 files changed, 156 insertions, 67 deletions
diff --git a/arch/arm/plat-aspeed/timer.c b/arch/arm/plat-aspeed/timer.c index 079d958c6e3f..6805beb24a12 100644 --- a/arch/arm/plat-aspeed/timer.c +++ b/arch/arm/plat-aspeed/timer.c @@ -16,19 +16,13 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include <asm/io.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> #include <linux/types.h> -#include <linux/kernel.h> #include <linux/init.h> -#include <linux/device.h> -#include <linux/spinlock.h> #include <linux/interrupt.h> -#include <linux/sched.h> - #include <linux/irq.h> -#include <asm/system.h> -#include <asm/io.h> -#include <mach/hardware.h> -#include <mach/irqs.h> #include <mach/time.h> #include <plat/ast-scu.h> @@ -37,72 +31,145 @@ #define ASPEED_TIMER2_VA_BASE (IO_ADDRESS(AST_TIMER_BASE)+ASPEED_TIMER2_OFFSET) #define ASPEED_TIMERC_VA_BASE (IO_ADDRESS(AST_TIMER_BASE)+ASPEED_TIMERRC_OFFSET) -/* - * Returns number of ms since last clock interrupt. Note that interrupts - * will have been disabled by do_gettimeoffset() - */ -static unsigned long ast_gettimeoffset(void) +#define ASPEED_TIMER_RELOAD_MAX 0xFFFFFFFF +#define ASPEED_TIMER_RELOAD_MIN 1 + +static struct clock_event_device clockevent_ast; + +static inline unsigned long ast_timer_read_count(void *base) { - volatile TimerStruct_t *timer0 = (TimerStruct_t *) ASPEED_TIMER0_VA_BASE; - unsigned long ticks1, ticks2;//, status; + volatile TimerStruct_t *timer = (volatile TimerStruct_t *)(base); + return timer->TimerValue; +} - /* - * Get the current number of ticks. Note that there is a race - * condition between us reading the timer and checking for - * an interrupt. We get around this by ensuring that the - * counter has not reloaded between our two reads. - */ - ticks2 = timer0->TimerValue; - do { - ticks1 = ticks2; -// status = readl(AST_RAW_STS(0));// __raw_readl(IO_ADDRESS(ASPEED_VIC_BASE) + ASPEED_VIC_RAW_STATUS_OFFSET); - ticks2 = timer0->TimerValue; - } while (ticks2 > ticks1); +/* change the timer count and load value (if requeseted) */ +static inline void ast_timer_set_count(void *base, unsigned long count, + unsigned long reload) +{ + volatile TimerStruct_t *timer = (volatile TimerStruct_t *)(base); + timer->TimerValue = count; + timer->TimerLoad = reload; +} - /* - * Number of ticks since last interrupt. - */ - ticks1 = TIMER_RELOAD - ticks2; +#define AST_TIMER_DISABLE 0 +#define AST_TIMER_ENABLE 1 - /* - * Interrupt pending? If so, we've reloaded once already. - */ -// if (status & (1 << IRQ_TIMER0)) -// ticks1 += TIMER_RELOAD; +static inline void ast_timer0_ctrl(int enable) +{ + volatile __u32 *timerc = (volatile __u32*) ASPEED_TIMERC_VA_BASE; + if (enable == AST_TIMER_ENABLE) { + *timerc |= TIMER0_ENABLE | TIMER0_RefExt; + } else { + *timerc &= ~TIMER0_ENABLE; + } +} - /* - * Convert the ticks to usecs - */ - return TICKS2USECS(ticks1); +static inline void ast_timer1_ctrl(int enable) +{ + volatile __u32 *timerc = (volatile __u32*) ASPEED_TIMERC_VA_BASE; + if (enable == AST_TIMER_ENABLE) { + *timerc |= TIMER1_ENABLE | TIMER1_RefExt; + } else { + *timerc &= ~TIMER1_ENABLE; + } } +static inline void ast_timer_disable_all() +{ + volatile __u32 *timerc = (volatile __u32*) ASPEED_TIMERC_VA_BASE; + *timerc = 0; +} /* - * IRQ handler for the timer + * clocksource */ -static irqreturn_t -ast_timer_interrupt(int irq, void *dev_id) +static irqreturn_t ast_clocksource_interrupt(int irq, void *dev_id) { + return IRQ_HANDLED; +} -// write_seqlock(&xtime_lock); +static struct irqaction ast_clocksource_irq = { + .name = "ast-clocksource", + .flags = IRQF_DISABLED | IRQF_TIMER, + .handler = ast_clocksource_interrupt, +}; + +static cycle_t read_cycles(void) +{ +#if 1 + return (cycles_t)(ASPEED_TIMER_RELOAD_MAX + - ast_timer_read_count(ASPEED_TIMER1_VA_BASE)); +#else + return (cycles_t) ast_timer_read_count(ASPEED_TIMER1_VA_BASE); +#endif +} + +static struct clocksource clocksource_ast = { + .name = "ast-clocksource", + .rating = 300, + .read = read_cycles, + .mask = CLOCKSOURCE_MASK(32), + .shift = 20, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; /* - * clear the interrupt in Irq.c + * clockevent */ -// IRQ_EDGE_CLEAR(0,IRQ_TIMER0); - - timer_tick(); +/* IRQ handler for the timer */ +static irqreturn_t ast_clockevent_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = &clockevent_ast; + evt->event_handler(evt); + return IRQ_HANDLED; +} +static struct irqaction ast_clockevent_irq = { + .name = "ast-clockevent", + .flags = IRQF_DISABLED | IRQF_TIMER, + .handler = ast_clockevent_interrupt, +}; -// write_sequnlock(&xtime_lock); +static int ast_timer_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + /* In this case, we shall not set the load value. */ + ast_timer_set_count(ASPEED_TIMER0_VA_BASE, cycles, 0); + /* turn on the timer */ + ast_timer0_ctrl(AST_TIMER_ENABLE); + return 0; +} - return IRQ_HANDLED; +static void ast_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + /* stop timer first */ + ast_timer0_ctrl(AST_TIMER_DISABLE); + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + ast_timer_set_count(ASPEED_TIMER0_VA_BASE, + TIMER_RELOAD - 1, TIMER_RELOAD - 1); + ast_timer0_ctrl(AST_TIMER_ENABLE); + break; + case CLOCK_EVT_MODE_ONESHOT: + /* + * Leave the timer disabled, ast_timer_set_next_event() will + * enable it later + */ + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_RESUME: + break; + } } -static struct irqaction ast_timer_irq = { - .name = "ast timer", - .flags = IRQF_DISABLED | IRQF_TIMER, - .handler = ast_timer_interrupt, +static struct clock_event_device clockevent_ast = { + .name = "ast-clockevent", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .shift = 32, + .set_next_event = ast_timer_set_next_event, + .set_mode = ast_timer_set_mode, }; /* @@ -110,28 +177,50 @@ static struct irqaction ast_timer_irq = { */ static void __init ast_setup_timer(void) { - volatile TimerStruct_t *timer0 = (volatile TimerStruct_t *) ASPEED_TIMER0_VA_BASE; - volatile __u32 *timerc = (volatile __u32*) ASPEED_TIMERC_VA_BASE; - /* * Initialise to a known state (all timers off) */ - *timerc = 0; - - timer0->TimerLoad = TIMER_RELOAD - 1; - timer0->TimerValue = TIMER_RELOAD - 1; - *timerc = TIMER0_ENABLE | TIMER0_RefExt; + ast_timer_disable_all(); /* - * Make irqs happen for the system timer + * For clock event, set the value and reload to 0, so that no interrupt even + * after enabling timer. */ + ast_timer_set_count(ASPEED_TIMER0_VA_BASE, 0, 0); + /* + * For clock source, set the value and reload to the max + */ + ast_timer_set_count(ASPEED_TIMER1_VA_BASE, + ASPEED_TIMER_RELOAD_MAX, ASPEED_TIMER_RELOAD_MAX); + + /* Enable timer */ + ast_timer0_ctrl(AST_TIMER_ENABLE); + ast_timer1_ctrl(AST_TIMER_ENABLE); + ast_scu_show_system_info(); - setup_irq(IRQ_TIMER0, &ast_timer_irq); - + /* irqs happen for the system timer */ + setup_irq(IRQ_TIMER0, &ast_clockevent_irq); + setup_irq(IRQ_TIMER1, &ast_clocksource_irq); + + /* setup clocksource */ + clocksource_ast.mult = clocksource_hz2mult(ASPEED_TIMER_CLKRATE, + clocksource_ast.shift); + if (clocksource_register(&clocksource_ast)) { + printk(KERN_ERR "Failed to register clock source %s", clocksource_ast.name); + } + + /* setup clockevent */ + clockevent_ast.mult = div_sc(ASPEED_TIMER_CLKRATE, NSEC_PER_SEC, + clockevent_ast.shift); + clockevent_ast.max_delta_ns = clockevent_delta2ns(ASPEED_TIMER_RELOAD_MAX, + &clockevent_ast); + clockevent_ast.min_delta_ns = clockevent_delta2ns(ASPEED_TIMER_RELOAD_MIN, + &clockevent_ast); + clockevent_ast.cpumask = cpumask_of_cpu(0); + clockevents_register_device(&clockevent_ast); } struct sys_timer ast_timer = { .init = ast_setup_timer, -// .offset = ast_gettimeoffset, }; |