From 4e8d76373c9fd7a1c1b401fc97ba01c0ecbb888f Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 28 Jan 2011 21:00:39 +0000 Subject: ARM: footbridge: convert to clockevents/clocksource The Footbridge platforms have some reasonable timers in the host bridge, which we use for most footbridge-based platforms. However, NetWinder's clock these using a spread-spectrum clock which makes them too unstable for time keeping. So we have to rely on the PIT. Convert both Footbridge timers and PIT timers to use the clocksource and clockevent infrastructure. Tested on Netwinder. Signed-off-by: Russell King --- arch/arm/mach-footbridge/dc21285-timer.c | 84 +++++++++++++++++++++++++------- 1 file changed, 66 insertions(+), 18 deletions(-) (limited to 'arch/arm/mach-footbridge/dc21285-timer.c') diff --git a/arch/arm/mach-footbridge/dc21285-timer.c b/arch/arm/mach-footbridge/dc21285-timer.c index bc5e83fb581..a921fe92b85 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 +#include #include #include #include -#include #include @@ -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, }; -- cgit v1.2.3-70-g09d2 From f2e0bf2181e4117fa7319be2c9249df968ad9096 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 28 Mar 2011 11:25:40 +0200 Subject: arm: footbridge: Make cksrc_dc21285_disable() void This clocksource function needs to be void. Signed-off-by: Thomas Gleixner --- arch/arm/mach-footbridge/dc21285-timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mach-footbridge/dc21285-timer.c') diff --git a/arch/arm/mach-footbridge/dc21285-timer.c b/arch/arm/mach-footbridge/dc21285-timer.c index a921fe92b85..5f1f9867fc7 100644 --- a/arch/arm/mach-footbridge/dc21285-timer.c +++ b/arch/arm/mach-footbridge/dc21285-timer.c @@ -30,7 +30,7 @@ static int cksrc_dc21285_enable(struct clocksource *cs) return 0; } -static int cksrc_dc21285_disable(struct clocksource *cs) +static void cksrc_dc21285_disable(struct clocksource *cs) { *CSR_TIMER2_CNTL = 0; } -- cgit v1.2.3-70-g09d2