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Diffstat (limited to 'arch/m68k/68000/timers.c')
-rw-r--r-- | arch/m68k/68000/timers.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/m68k/68000/timers.c b/arch/m68k/68000/timers.c new file mode 100644 index 000000000..0d0417ceb --- /dev/null +++ b/arch/m68k/68000/timers.c @@ -0,0 +1,135 @@ +/***************************************************************************/ + +/* + * timers.c - Generic hardware timer support. + * + * Copyright (C) 1993 Hamish Macdonald + * Copyright (C) 1999 D. Jeff Dionne + * Copyright (C) 2001 Georges Menie, Ken Desmet + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +/***************************************************************************/ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/clocksource.h> +#include <linux/rtc.h> +#include <asm/setup.h> +#include <asm/machdep.h> +#include <asm/MC68VZ328.h> + +/***************************************************************************/ + +#if defined(CONFIG_DRAGEN2) +/* with a 33.16 MHz clock, this will give usec resolution to the time functions */ +#define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK +#define CLOCK_PRE 7 +#define TICKS_PER_JIFFY 41450 + +#elif defined(CONFIG_XCOPILOT_BUGS) +/* + * The only thing I know is that CLK32 is not available on Xcopilot + * I have little idea about what frequency SYSCLK has on Xcopilot. + * The values for prescaler and compare registers were simply + * taken from the original source + */ +#define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK +#define CLOCK_PRE 2 +#define TICKS_PER_JIFFY 0xd7e4 + +#else +/* default to using the 32Khz clock */ +#define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ +#define CLOCK_PRE 31 +#define TICKS_PER_JIFFY 10 +#endif + +static u32 m68328_tick_cnt; + +/***************************************************************************/ + +static irqreturn_t hw_tick(int irq, void *dummy) +{ + /* Reset Timer1 */ + TSTAT &= 0; + + m68328_tick_cnt += TICKS_PER_JIFFY; + legacy_timer_tick(1); + return IRQ_HANDLED; +} + +/***************************************************************************/ + +static u64 m68328_read_clk(struct clocksource *cs) +{ + unsigned long flags; + u32 cycles; + + local_irq_save(flags); + cycles = m68328_tick_cnt + TCN; + local_irq_restore(flags); + + return cycles; +} + +/***************************************************************************/ + +static struct clocksource m68328_clk = { + .name = "timer", + .rating = 250, + .read = m68328_read_clk, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +/***************************************************************************/ + +void hw_timer_init(void) +{ + int ret; + + /* disable timer 1 */ + TCTL = 0; + + /* set ISR */ + ret = request_irq(TMR_IRQ_NUM, hw_tick, IRQF_TIMER, "timer", NULL); + if (ret) { + pr_err("Failed to request irq %d (timer): %pe\n", TMR_IRQ_NUM, + ERR_PTR(ret)); + } + + /* Restart mode, Enable int, Set clock source */ + TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE; + TPRER = CLOCK_PRE; + TCMP = TICKS_PER_JIFFY; + + /* Enable timer 1 */ + TCTL |= TCTL_TEN; + clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ); +} + +/***************************************************************************/ + +int m68328_hwclk(int set, struct rtc_time *t) +{ + if (!set) { + long now = RTCTIME; + t->tm_year = 1; + t->tm_mon = 0; + t->tm_mday = 1; + t->tm_hour = (now >> 24) % 24; + t->tm_min = (now >> 16) % 60; + t->tm_sec = now % 60; + } + + return 0; +} + +/***************************************************************************/ |