diff options
Diffstat (limited to 'arch/arm/plat-omap/counter_32k.c')
-rw-r--r-- | arch/arm/plat-omap/counter_32k.c | 91 |
1 files changed, 39 insertions, 52 deletions
diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c index 5068fe5a691..b2f634ba7bc 100644 --- a/arch/arm/plat-omap/counter_32k.c +++ b/arch/arm/plat-omap/counter_32k.c @@ -27,19 +27,20 @@ #include <plat/clock.h> +/* OMAP2_32KSYNCNT_CR_OFF: offset of 32ksync counter register */ +#define OMAP2_32KSYNCNT_CR_OFF 0x10 + /* * 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 +static void __iomem *sync32k_cnt_reg; static u32 notrace omap_32k_read_sched_clock(void) { - return timer_32k_base ? __raw_readl(timer_32k_base) : 0; + return sync32k_cnt_reg ? __raw_readl(sync32k_cnt_reg) : 0; } /** @@ -59,7 +60,7 @@ void read_persistent_clock(struct timespec *ts) struct timespec *tsp = &persistent_ts; last_cycles = cycles; - cycles = timer_32k_base ? __raw_readl(timer_32k_base) : 0; + cycles = sync32k_cnt_reg ? __raw_readl(sync32k_cnt_reg) : 0; delta = cycles - last_cycles; nsecs = clocksource_cyc2ns(delta, persistent_mult, persistent_shift); @@ -68,54 +69,40 @@ void read_persistent_clock(struct timespec *ts) *ts = *tsp; } -int __init omap_init_clocksource_32k(void) +/** + * omap_init_clocksource_32k - setup and register counter 32k as a + * kernel clocksource + * @pbase: base addr of counter_32k module + * @size: size of counter_32k to map + * + * Returns 0 upon success or negative error code upon failure. + * + */ +int __init omap_init_clocksource_32k(void __iomem *vbase) { - static char err[] __initdata = KERN_ERR - "%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()) { - pbase = OMAP16XX_TIMER_32K_SYNCHRONIZED; - size = SZ_1K; - } else if (cpu_is_omap2420()) - pbase = OMAP2420_32KSYNCT_BASE + 0x10; - else if (cpu_is_omap2430()) - pbase = OMAP2430_32KSYNCT_BASE + 0x10; - else if (cpu_is_omap34xx()) - pbase = OMAP3430_32KSYNCT_BASE + 0x10; - else if (cpu_is_omap44xx()) - 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); - - 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_mmio_init(base, "32k_counter", 32768, 250, 32, - clocksource_mmio_readl_up)) - printk(err, "32k_counter"); - - setup_sched_clock(omap_32k_read_sched_clock, 32, 32768); + int ret; + + /* + * 32k sync Counter register offset is at 0x10 + */ + sync32k_cnt_reg = vbase + OMAP2_32KSYNCNT_CR_OFF; + + /* + * 120000 rough estimate from the calculations in + * __clocksource_updatefreq_scale. + */ + clocks_calc_mult_shift(&persistent_mult, &persistent_shift, + 32768, NSEC_PER_SEC, 120000); + + ret = clocksource_mmio_init(sync32k_cnt_reg, "32k_counter", 32768, + 250, 32, clocksource_mmio_readl_up); + if (ret) { + pr_err("32k_counter: can't register clocksource\n"); + return ret; } + + setup_sched_clock(omap_32k_read_sched_clock, 32, 32768); + pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n"); + return 0; } |