diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/Kconfig | 2 | ||||
| -rw-r--r-- | arch/arm/mach-footbridge/dc21285-timer.c | 84 | ||||
| -rw-r--r-- | arch/arm/mach-footbridge/isa-timer.c | 129 |
3 files changed, 152 insertions, 63 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 5cff165..6d9fbfe 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -346,7 +346,7 @@ config ARCH_FOOTBRIDGE bool "FootBridge" select CPU_SA110 select FOOTBRIDGE - select ARCH_USES_GETTIMEOFFSET + select GENERIC_CLOCKEVENTS help Support for systems based on the DC21285 companion chip ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder. diff --git a/arch/arm/mach-footbridge/dc21285-timer.c b/arch/arm/mach-footbridge/dc21285-timer.c index bc5e83f..a921fe9 100644 --- a/arch/arm/mach-footbridge/dc21285-timer.c +++ b/arch/arm/mach-footbridge/dc21285-timer.c @@ -4,10 +4,11 @@ * Copyright (C) 1998 Russell King. * Copyright (C) 1998 Phil Blundell */ +#include <linux/clockchips.h> +#include <linux/clocksource.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/irq.h> -#include <linux/spinlock.h> #include <asm/irq.h> @@ -16,32 +17,76 @@ #include "common.h" -/* - * Footbridge timer 1 support. - */ -static unsigned long timer1_latch; +static cycle_t cksrc_dc21285_read(struct clocksource *cs) +{ + return cs->mask - *CSR_TIMER2_VALUE; +} -static unsigned long timer1_gettimeoffset (void) +static int cksrc_dc21285_enable(struct clocksource *cs) { - unsigned long value = timer1_latch - *CSR_TIMER1_VALUE; + *CSR_TIMER2_LOAD = cs->mask; + *CSR_TIMER2_CLR = 0; + *CSR_TIMER2_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16; + return 0; +} - return ((tick_nsec / 1000) * value) / timer1_latch; +static int cksrc_dc21285_disable(struct clocksource *cs) +{ + *CSR_TIMER2_CNTL = 0; } -static irqreturn_t -timer1_interrupt(int irq, void *dev_id) +static struct clocksource cksrc_dc21285 = { + .name = "dc21285_timer2", + .rating = 200, + .read = cksrc_dc21285_read, + .enable = cksrc_dc21285_enable, + .disable = cksrc_dc21285_disable, + .mask = CLOCKSOURCE_MASK(24), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static void ckevt_dc21285_set_mode(enum clock_event_mode mode, + struct clock_event_device *c) { + switch (mode) { + case CLOCK_EVT_MODE_RESUME: + case CLOCK_EVT_MODE_PERIODIC: + *CSR_TIMER1_CLR = 0; + *CSR_TIMER1_LOAD = (mem_fclk_21285 + 8 * HZ) / (16 * HZ); + *CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD | + TIMER_CNTL_DIV16; + break; + + default: + *CSR_TIMER1_CNTL = 0; + break; + } +} + +static struct clock_event_device ckevt_dc21285 = { + .name = "dc21285_timer1", + .features = CLOCK_EVT_FEAT_PERIODIC, + .rating = 200, + .irq = IRQ_TIMER1, + .set_mode = ckevt_dc21285_set_mode, +}; + +static irqreturn_t timer1_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *ce = dev_id; + *CSR_TIMER1_CLR = 0; - timer_tick(); + ce->event_handler(ce); return IRQ_HANDLED; } static struct irqaction footbridge_timer_irq = { - .name = "Timer1 timer tick", + .name = "dc21285_timer1", .handler = timer1_interrupt, .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .dev_id = &ckevt_dc21285, }; /* @@ -49,16 +94,19 @@ static struct irqaction footbridge_timer_irq = { */ static void __init footbridge_timer_init(void) { - timer1_latch = (mem_fclk_21285 + 8 * HZ) / (16 * HZ); + struct clock_event_device *ce = &ckevt_dc21285; + + clocksource_register_hz(&cksrc_dc21285, (mem_fclk_21285 + 8) / 16); + + setup_irq(ce->irq, &footbridge_timer_irq); - *CSR_TIMER1_CLR = 0; - *CSR_TIMER1_LOAD = timer1_latch; - *CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD | TIMER_CNTL_DIV16; + clockevents_calc_mult_shift(ce, mem_fclk_21285, 5); + ce->max_delta_ns = clockevent_delta2ns(0xffffff, ce); + ce->min_delta_ns = clockevent_delta2ns(0x000004, ce); - setup_irq(IRQ_TIMER1, &footbridge_timer_irq); + clockevents_register_device(ce); } struct sys_timer footbridge_timer = { .init = footbridge_timer_init, - .offset = timer1_gettimeoffset, }; diff --git a/arch/arm/mach-footbridge/isa-timer.c b/arch/arm/mach-footbridge/isa-timer.c index f488fa2..441c6ce 100644 --- a/arch/arm/mach-footbridge/isa-timer.c +++ b/arch/arm/mach-footbridge/isa-timer.c @@ -4,10 +4,13 @@ * Copyright (C) 1998 Russell King. * Copyright (C) 1998 Phil Blundell */ +#include <linux/clockchips.h> +#include <linux/clocksource.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/io.h> +#include <linux/timex.h> #include <asm/irq.h> @@ -15,77 +18,115 @@ #include "common.h" -/* - * ISA timer tick support - */ -#define mSEC_10_from_14 ((14318180 + 100) / 200) +#define PIT_MODE 0x43 +#define PIT_CH0 0x40 + +#define PIT_LATCH ((PIT_TICK_RATE + HZ / 2) / HZ) -static unsigned long isa_gettimeoffset(void) +static cycle_t pit_read(struct clocksource *cs) { + unsigned long flags; + static int old_count; + static u32 old_jifs; int count; + u32 jifs; - static int count_p = (mSEC_10_from_14/6); /* for the first call after boot */ - static unsigned long jiffies_p = 0; + raw_local_irq_save(flags); - /* - * cache volatile jiffies temporarily; we have IRQs turned off. - */ - unsigned long jiffies_t; + jifs = jiffies; + outb_p(0x00, PIT_MODE); /* latch the count */ + count = inb_p(PIT_CH0); /* read the latched count */ + count |= inb_p(PIT_CH0) << 8; - /* timer count may underflow right here */ - outb_p(0x00, 0x43); /* latch the count ASAP */ + if (count > old_count && jifs == old_jifs) + count = old_count; - count = inb_p(0x40); /* read the latched count */ + old_count = count; + old_jifs = jifs; - /* - * We do this guaranteed double memory access instead of a _p - * postfix in the previous port access. Wheee, hackady hack - */ - jiffies_t = jiffies; + raw_local_irq_restore(flags); - count |= inb_p(0x40) << 8; + count = (PIT_LATCH - 1) - count; - /* Detect timer underflows. If we haven't had a timer tick since - the last time we were called, and time is apparently going - backwards, the counter must have wrapped during this routine. */ - if ((jiffies_t == jiffies_p) && (count > count_p)) - count -= (mSEC_10_from_14/6); - else - jiffies_p = jiffies_t; + return (cycle_t)(jifs * PIT_LATCH) + count; +} - count_p = count; +static struct clocksource pit_cs = { + .name = "pit", + .rating = 110, + .read = pit_read, + .mask = CLOCKSOURCE_MASK(32), +}; - count = (((mSEC_10_from_14/6)-1) - count) * (tick_nsec / 1000); - count = (count + (mSEC_10_from_14/6)/2) / (mSEC_10_from_14/6); +static void pit_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long flags; + + raw_local_irq_save(flags); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + outb_p(0x34, PIT_MODE); + outb_p(PIT_LATCH & 0xff, PIT_CH0); + outb_p(PIT_LATCH >> 8, PIT_CH0); + break; + + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + outb_p(0x30, PIT_MODE); + outb_p(0, PIT_CH0); + outb_p(0, PIT_CH0); + break; + + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_RESUME: + break; + } + local_irq_restore(flags); +} - return count; +static int pit_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + return 0; } -static irqreturn_t -isa_timer_interrupt(int irq, void *dev_id) +static struct clock_event_device pit_ce = { + .name = "pit", + .features = CLOCK_EVT_FEAT_PERIODIC, + .set_mode = pit_set_mode, + .set_next_event = pit_set_next_event, + .shift = 32, +}; + +static irqreturn_t pit_timer_interrupt(int irq, void *dev_id) { - timer_tick(); + struct clock_event_device *ce = dev_id; + ce->event_handler(ce); return IRQ_HANDLED; } -static struct irqaction isa_timer_irq = { - .name = "ISA timer tick", - .handler = isa_timer_interrupt, +static struct irqaction pit_timer_irq = { + .name = "pit", + .handler = pit_timer_interrupt, .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .dev_id = &pit_ce, }; static void __init isa_timer_init(void) { - /* enable PIT timer */ - /* set for periodic (4) and LSB/MSB write (0x30) */ - outb(0x34, 0x43); - outb((mSEC_10_from_14/6) & 0xFF, 0x40); - outb((mSEC_10_from_14/6) >> 8, 0x40); + pit_ce.cpumask = cpumask_of(smp_processor_id()); + pit_ce.mult = div_sc(PIT_TICK_RATE, NSEC_PER_SEC, pit_ce.shift); + pit_ce.max_delta_ns = clockevent_delta2ns(0x7fff, &pit_ce); + pit_ce.min_delta_ns = clockevent_delta2ns(0x000f, &pit_ce); + + clocksource_register_hz(&pit_cs, PIT_TICK_RATE); - setup_irq(IRQ_ISA_TIMER, &isa_timer_irq); + setup_irq(pit_ce.irq, &pit_timer_irq); + clockevents_register_device(&pit_ce); } struct sys_timer isa_timer = { .init = isa_timer_init, - .offset = isa_gettimeoffset, }; |