diff options
Diffstat (limited to 'arch/arm/plat-omap/counter_32k.c')
| -rw-r--r-- | arch/arm/plat-omap/counter_32k.c | 121 |
1 files changed, 34 insertions, 87 deletions
diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c index c13bc3d3eb2..a6cbb712da5 100644 --- a/arch/arm/plat-omap/counter_32k.c +++ b/arch/arm/plat-omap/counter_32k.c @@ -18,6 +18,7 @@ #include <linux/err.h> #include <linux/io.h> #include <linux/sched.h> +#include <linux/clocksource.h> #include <asm/sched_clock.h> @@ -26,87 +27,16 @@ #include <plat/clock.h> - /* * 32KHz clocksource ... always available, on pretty most chips except * OMAP 730 and 1510. Other timers could be used as clocksources, with * higher resolution in free-running counter modes (e.g. 12 MHz xtal), * but systems won't necessarily want to spend resources that way. */ +static void __iomem *timer_32k_base; #define OMAP16XX_TIMER_32K_SYNCHRONIZED 0xfffbc410 -#include <linux/clocksource.h> - -/* - * offset_32k holds the init time counter value. It is then subtracted - * from every counter read to achieve a counter that counts time from the - * kernel boot (needed for sched_clock()). - */ -static u32 offset_32k __read_mostly; - -#ifdef CONFIG_ARCH_OMAP16XX -static cycle_t notrace omap16xx_32k_read(struct clocksource *cs) -{ - return omap_readl(OMAP16XX_TIMER_32K_SYNCHRONIZED) - offset_32k; -} -#else -#define omap16xx_32k_read NULL -#endif - -#ifdef CONFIG_SOC_OMAP2420 -static cycle_t notrace omap2420_32k_read(struct clocksource *cs) -{ - return omap_readl(OMAP2420_32KSYNCT_BASE + 0x10) - offset_32k; -} -#else -#define omap2420_32k_read NULL -#endif - -#ifdef CONFIG_SOC_OMAP2430 -static cycle_t notrace omap2430_32k_read(struct clocksource *cs) -{ - return omap_readl(OMAP2430_32KSYNCT_BASE + 0x10) - offset_32k; -} -#else -#define omap2430_32k_read NULL -#endif - -#ifdef CONFIG_ARCH_OMAP3 -static cycle_t notrace omap34xx_32k_read(struct clocksource *cs) -{ - return omap_readl(OMAP3430_32KSYNCT_BASE + 0x10) - offset_32k; -} -#else -#define omap34xx_32k_read NULL -#endif - -#ifdef CONFIG_ARCH_OMAP4 -static cycle_t notrace omap44xx_32k_read(struct clocksource *cs) -{ - return omap_readl(OMAP4430_32KSYNCT_BASE + 0x10) - offset_32k; -} -#else -#define omap44xx_32k_read NULL -#endif - -/* - * Kernel assumes that sched_clock can be called early but may not have - * things ready yet. - */ -static cycle_t notrace omap_32k_read_dummy(struct clocksource *cs) -{ - return 0; -} - -static struct clocksource clocksource_32k = { - .name = "32k_counter", - .rating = 250, - .read = omap_32k_read_dummy, - .mask = CLOCKSOURCE_MASK(32), - .flags = CLOCK_SOURCE_IS_CONTINUOUS, -}; - /* * Returns current time from boot in nsecs. It's OK for this to wrap * around for now, as it's just a relative time stamp. @@ -122,7 +52,7 @@ static DEFINE_CLOCK_DATA(cd); static inline unsigned long long notrace _omap_32k_sched_clock(void) { - u32 cyc = clocksource_32k.read(&clocksource_32k); + u32 cyc = timer_32k_base ? __raw_readl(timer_32k_base) : 0; return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0, SC_MULT, SC_SHIFT); } @@ -140,7 +70,7 @@ unsigned long long notrace omap_32k_sched_clock(void) static void notrace omap_update_sched_clock(void) { - u32 cyc = clocksource_32k.read(&clocksource_32k); + u32 cyc = timer_32k_base ? __raw_readl(timer_32k_base) : 0; update_sched_clock(&cd, cyc, (u32)~0); } @@ -153,6 +83,7 @@ static void notrace omap_update_sched_clock(void) */ static struct timespec persistent_ts; static cycles_t cycles, last_cycles; +static unsigned int persistent_mult, persistent_shift; void read_persistent_clock(struct timespec *ts) { unsigned long long nsecs; @@ -160,11 +91,10 @@ void read_persistent_clock(struct timespec *ts) struct timespec *tsp = &persistent_ts; last_cycles = cycles; - cycles = clocksource_32k.read(&clocksource_32k); + cycles = timer_32k_base ? __raw_readl(timer_32k_base) : 0; delta = cycles - last_cycles; - nsecs = clocksource_cyc2ns(delta, - clocksource_32k.mult, clocksource_32k.shift); + nsecs = clocksource_cyc2ns(delta, persistent_mult, persistent_shift); timespec_add_ns(tsp, nsecs); *ts = *tsp; @@ -176,29 +106,46 @@ int __init omap_init_clocksource_32k(void) "%s: can't register clocksource!\n"; if (cpu_is_omap16xx() || cpu_class_is_omap2()) { + u32 pbase; + unsigned long size = SZ_4K; + void __iomem *base; struct clk *sync_32k_ick; - if (cpu_is_omap16xx()) - clocksource_32k.read = omap16xx_32k_read; - else if (cpu_is_omap2420()) - clocksource_32k.read = omap2420_32k_read; + if (cpu_is_omap16xx()) { + pbase = OMAP16XX_TIMER_32K_SYNCHRONIZED; + size = SZ_1K; + } else if (cpu_is_omap2420()) + pbase = OMAP2420_32KSYNCT_BASE + 0x10; else if (cpu_is_omap2430()) - clocksource_32k.read = omap2430_32k_read; + pbase = OMAP2430_32KSYNCT_BASE + 0x10; else if (cpu_is_omap34xx()) - clocksource_32k.read = omap34xx_32k_read; + pbase = OMAP3430_32KSYNCT_BASE + 0x10; else if (cpu_is_omap44xx()) - clocksource_32k.read = omap44xx_32k_read; + pbase = OMAP4430_32KSYNCT_BASE + 0x10; else return -ENODEV; + /* For this to work we must have a static mapping in io.c for this area */ + base = ioremap(pbase, size); + if (!base) + return -ENODEV; + sync_32k_ick = clk_get(NULL, "omap_32ksync_ick"); if (!IS_ERR(sync_32k_ick)) clk_enable(sync_32k_ick); - offset_32k = clocksource_32k.read(&clocksource_32k); + timer_32k_base = base; + + /* + * 120000 rough estimate from the calculations in + * __clocksource_updatefreq_scale. + */ + clocks_calc_mult_shift(&persistent_mult, &persistent_shift, + 32768, NSEC_PER_SEC, 120000); - if (clocksource_register_hz(&clocksource_32k, 32768)) - printk(err, clocksource_32k.name); + if (clocksource_mmio_init(base, "32k_counter", 32768, 250, 32, + clocksource_mmio_readl_up)) + printk(err, "32k_counter"); init_fixed_sched_clock(&cd, omap_update_sched_clock, 32, 32768, SC_MULT, SC_SHIFT); |