diff options
author | Greg Ungerer <gerg@uclinux.org> | 2014-08-19 11:39:09 +1000 |
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committer | Greg Ungerer <gerg@uclinux.org> | 2014-09-29 09:18:34 +1000 |
commit | f86b9e03837beafb4b48d53a76ee4b88559226de (patch) | |
tree | 53a673c3719aec83c6c55c265ed6e6433d6550ca /arch/m68k/coldfire/sltimers.c | |
parent | fe82dcec644244676d55a1384c958d5f67979adb (diff) |
m68k: move coldfire platform code
Move the m68k ColdFire platform support code directory to be with the
existing m68k platforms. Although the ColdFire is not a platform as such,
we have always kept all its support together. No reason to change that
as this time.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k/coldfire/sltimers.c')
-rw-r--r-- | arch/m68k/coldfire/sltimers.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/m68k/coldfire/sltimers.c b/arch/m68k/coldfire/sltimers.c new file mode 100644 index 00000000000..831a08cf6f4 --- /dev/null +++ b/arch/m68k/coldfire/sltimers.c @@ -0,0 +1,149 @@ +/***************************************************************************/ + +/* + * sltimers.c -- generic ColdFire slice timer support. + * + * Copyright (C) 2009-2010, Philippe De Muyter <phdm@macqel.be> + * based on + * timers.c -- generic ColdFire hardware timer support. + * Copyright (C) 1999-2008, Greg Ungerer <gerg@snapgear.com> + */ + +/***************************************************************************/ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/profile.h> +#include <linux/clocksource.h> +#include <asm/io.h> +#include <asm/traps.h> +#include <asm/machdep.h> +#include <asm/coldfire.h> +#include <asm/mcfslt.h> +#include <asm/mcfsim.h> + +/***************************************************************************/ + +#ifdef CONFIG_HIGHPROFILE + +/* + * By default use Slice Timer 1 as the profiler clock timer. + */ +#define PA(a) (MCFSLT_TIMER1 + (a)) + +/* + * Choose a reasonably fast profile timer. Make it an odd value to + * try and get good coverage of kernel operations. + */ +#define PROFILEHZ 1013 + +irqreturn_t mcfslt_profile_tick(int irq, void *dummy) +{ + /* Reset Slice Timer 1 */ + __raw_writel(MCFSLT_SSR_BE | MCFSLT_SSR_TE, PA(MCFSLT_SSR)); + if (current->pid) + profile_tick(CPU_PROFILING); + return IRQ_HANDLED; +} + +static struct irqaction mcfslt_profile_irq = { + .name = "profile timer", + .flags = IRQF_TIMER, + .handler = mcfslt_profile_tick, +}; + +void mcfslt_profile_init(void) +{ + printk(KERN_INFO "PROFILE: lodging TIMER 1 @ %dHz as profile timer\n", + PROFILEHZ); + + setup_irq(MCF_IRQ_PROFILER, &mcfslt_profile_irq); + + /* Set up TIMER 2 as high speed profile clock */ + __raw_writel(MCF_BUSCLK / PROFILEHZ - 1, PA(MCFSLT_STCNT)); + __raw_writel(MCFSLT_SCR_RUN | MCFSLT_SCR_IEN | MCFSLT_SCR_TEN, + PA(MCFSLT_SCR)); + +} + +#endif /* CONFIG_HIGHPROFILE */ + +/***************************************************************************/ + +/* + * By default use Slice Timer 0 as the system clock timer. + */ +#define TA(a) (MCFSLT_TIMER0 + (a)) + +static u32 mcfslt_cycles_per_jiffy; +static u32 mcfslt_cnt; + +static irq_handler_t timer_interrupt; + +static irqreturn_t mcfslt_tick(int irq, void *dummy) +{ + /* Reset Slice Timer 0 */ + __raw_writel(MCFSLT_SSR_BE | MCFSLT_SSR_TE, TA(MCFSLT_SSR)); + mcfslt_cnt += mcfslt_cycles_per_jiffy; + return timer_interrupt(irq, dummy); +} + +static struct irqaction mcfslt_timer_irq = { + .name = "timer", + .flags = IRQF_TIMER, + .handler = mcfslt_tick, +}; + +static cycle_t mcfslt_read_clk(struct clocksource *cs) +{ + unsigned long flags; + u32 cycles, scnt; + + local_irq_save(flags); + scnt = __raw_readl(TA(MCFSLT_SCNT)); + cycles = mcfslt_cnt; + if (__raw_readl(TA(MCFSLT_SSR)) & MCFSLT_SSR_TE) { + cycles += mcfslt_cycles_per_jiffy; + scnt = __raw_readl(TA(MCFSLT_SCNT)); + } + local_irq_restore(flags); + + /* subtract because slice timers count down */ + return cycles + ((mcfslt_cycles_per_jiffy - 1) - scnt); +} + +static struct clocksource mcfslt_clk = { + .name = "slt", + .rating = 250, + .read = mcfslt_read_clk, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +void hw_timer_init(irq_handler_t handler) +{ + mcfslt_cycles_per_jiffy = MCF_BUSCLK / HZ; + /* + * The coldfire slice timer (SLT) runs from STCNT to 0 included, + * then STCNT again and so on. It counts thus actually + * STCNT + 1 steps for 1 tick, not STCNT. So if you want + * n cycles, initialize STCNT with n - 1. + */ + __raw_writel(mcfslt_cycles_per_jiffy - 1, TA(MCFSLT_STCNT)); + __raw_writel(MCFSLT_SCR_RUN | MCFSLT_SCR_IEN | MCFSLT_SCR_TEN, + TA(MCFSLT_SCR)); + /* initialize mcfslt_cnt knowing that slice timers count down */ + mcfslt_cnt = mcfslt_cycles_per_jiffy; + + timer_interrupt = handler; + setup_irq(MCF_IRQ_TIMER, &mcfslt_timer_irq); + + clocksource_register_hz(&mcfslt_clk, MCF_BUSCLK); + +#ifdef CONFIG_HIGHPROFILE + mcfslt_profile_init(); +#endif +} |