Messages in this thread | | | Date | Fri, 7 Aug 2009 18:48:15 +0800 | Subject | Re: [PATCH] Add generic clock events support for w90p910 timer | From | Wan ZongShun <> |
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Dear Russell,
When involving the clocksource function by means of timer1, I find my system running seems to be slow, and the printed console information shown slowly too.
Regarding timer1 setting, I only set the counter enable bit, periodic mode bit and fill in the timer initial count register, which is a 24bit register, I think it can work ok.
Any else setting missed regarding linux api of clocksource ?
2009/8/5 Wan ZongShun <mcuos.com@gmail.com>: > Dear sirs, > > I fixed this patch according to Russell's advice, and added > time1 for clocksource. > > Either setting 'LOCK_EVT_MODE_PERIODIC' or setting 'CLOCK_EVT_FEAT_ONESHOT' can > run in my w90p910 evaluation board. but, if I set 'future' to following: > > ".features = CLOCK_EVT_MODE_PERIODIC | CLOCK_EVT_FEAT_ONESHOT," > > If so, the timer works on the periodic mode. > > > Signed-off-by: Wan ZongShun <mcuos.com@gmail.com> > > --- > arch/arm/Kconfig | 2 + > arch/arm/mach-w90x900/clock.c | 6 ++ > arch/arm/mach-w90x900/time.c | 151 ++++++++++++++++++++++++++++++++------ > arch/arm/mach-w90x900/w90p910.c | 2 + > 4 files changed, 137 insertions(+), 24 deletions(-) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index c3fed1e..8c4f03d 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -495,6 +495,8 @@ config ARCH_W90X900 > select GENERIC_GPIO > select HAVE_CLK > select COMMON_CLKDEV > + select GENERIC_TIME > + select GENERIC_CLOCKEVENTS > help > Support for Nuvoton (Winbond logic dept.) ARM9 processor,You > can login www.mcuos.com or www.nuvoton.com to know more. > diff --git a/arch/arm/mach-w90x900/clock.c b/arch/arm/mach-w90x900/clock.c > index 49cf1fb..70b6710 100644 > --- a/arch/arm/mach-w90x900/clock.c > +++ b/arch/arm/mach-w90x900/clock.c > @@ -55,6 +55,12 @@ void clk_disable(struct clk *clk) > } > EXPORT_SYMBOL(clk_disable); > > +unsigned long clk_get_rate(struct clk *clk) > +{ > + return 15000000; > +} > +EXPORT_SYMBOL(clk_get_rate); > + > void w90x900_clk_enable(struct clk *clk, int enable) > { > unsigned int clocks = clk->cken; > diff --git a/arch/arm/mach-w90x900/time.c b/arch/arm/mach-w90x900/time.c > index bcc838f..5e06770 100644 > --- a/arch/arm/mach-w90x900/time.c > +++ b/arch/arm/mach-w90x900/time.c > @@ -3,7 +3,7 @@ > * > * Based on linux/arch/arm/plat-s3c24xx/time.c by Ben Dooks > * > - * Copyright (c) 2008 Nuvoton technology corporation > + * Copyright (c) 2009 Nuvoton technology corporation > * All rights reserved. > * > * Wan ZongShun <mcuos.com@gmail.com> > @@ -23,6 +23,8 @@ > #include <linux/clk.h> > #include <linux/io.h> > #include <linux/leds.h> > +#include <linux/clocksource.h> > +#include <linux/clockchips.h> > > #include <asm/mach-types.h> > #include <asm/mach/irq.h> > @@ -31,49 +33,150 @@ > #include <mach/map.h> > #include <mach/regs-timer.h> > > -static unsigned long w90x900_gettimeoffset(void) > +#define RESETINT 0x1f > +#define PERIOD (0x01 << 27) > +#define ONESHOT (0x00 << 27) > +#define COUNTEN (0x01 << 30) > +#define INTEN (0x01 << 29) > + > +#define TICKS_PER_SEC 100 > +#define PRESCALE 0x63 /* Divider = prescale + 1 */ > + > +unsigned int timer0_load; > + > +static void w90p910_clockevent_setmode(enum clock_event_mode mode, > + struct clock_event_device *clk) > { > + unsigned int val; > + > + val = __raw_readl(REG_TCSR0); > + val &= ~(0x03 << 27); > + > + switch (mode) { > + case CLOCK_EVT_MODE_PERIODIC: > + __raw_writel(timer0_load, REG_TICR0); > + val |= (PERIOD | COUNTEN | INTEN | PRESCALE); > + break; > + > + case CLOCK_EVT_MODE_ONESHOT: > + val |= (ONESHOT | COUNTEN | INTEN | PRESCALE); > + break; > + > + case CLOCK_EVT_MODE_UNUSED: > + case CLOCK_EVT_MODE_SHUTDOWN: > + case CLOCK_EVT_MODE_RESUME: > + break; > + } > + > + __raw_writel(val, REG_TCSR0); > +} > + > +static int w90p910_clockevent_setnextevent(unsigned long evt, > + struct clock_event_device *clk) > +{ > + unsigned int val; > + > + __raw_writel(evt, REG_TICR0); > + > + val = __raw_readl(REG_TCSR0); > + val |= (COUNTEN | INTEN | PRESCALE); > + __raw_writel(val, REG_TCSR0); > + > return 0; > } > > +static struct clock_event_device w90p910_clockevent_device = { > + .name = "w90p910-timer0", > + .shift = 32, > + .features = CLOCK_EVT_MODE_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, > + .set_mode = w90p910_clockevent_setmode, > + .set_next_event = w90p910_clockevent_setnextevent, > + .rating = 300, > +}; > + > /*IRQ handler for the timer*/ > > -static irqreturn_t > -w90x900_timer_interrupt(int irq, void *dev_id) > +static irqreturn_t w90p910_timer0_interrupt(int irq, void *dev_id) > { > - timer_tick(); > + struct clock_event_device *evt = &w90p910_clockevent_device; > + > __raw_writel(0x01, REG_TISR); /* clear TIF0 */ > + > + evt->event_handler(evt); > return IRQ_HANDLED; > } > > -static struct irqaction w90x900_timer_irq = { > - .name = "w90x900 Timer Tick", > +static struct irqaction w90p910_timer0_irq = { > + .name = "w90p910-timer0", > .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, > - .handler = w90x900_timer_interrupt, > + .handler = w90p910_timer0_interrupt, > }; > > -/*Set up timer reg.*/ > +static void __init w90p910_clockevents_init(unsigned int rate) > +{ > + w90p910_clockevent_device.mult = div_sc(rate, NSEC_PER_SEC, > + w90p910_clockevent_device.shift); > + w90p910_clockevent_device.max_delta_ns = clockevent_delta2ns(0xffffffff, > + &w90p910_clockevent_device); > + w90p910_clockevent_device.min_delta_ns = clockevent_delta2ns(0xf, > + &w90p910_clockevent_device); > + w90p910_clockevent_device.cpumask = cpumask_of(0); > > -static void w90x900_timer_setup(void) > + clockevents_register_device(&w90p910_clockevent_device); > +} > + > +static cycle_t w90p910_get_cycles(struct clocksource *cs) > { > - __raw_writel(0, REG_TCSR0); > - __raw_writel(0, REG_TCSR1); > - __raw_writel(0, REG_TCSR2); > - __raw_writel(0, REG_TCSR3); > - __raw_writel(0, REG_TCSR4); > - __raw_writel(0x1F, REG_TISR); > - __raw_writel(15000000/(100 * 100), REG_TICR0); > - __raw_writel(0x68000063, REG_TCSR0); > + return ~__raw_readl(REG_TDR1); > } > > -static void __init w90x900_timer_init(void) > +static struct clocksource clocksource_w90p910 = { > + .name = "w90p910-timer1", > + .rating = 200, > + .read = w90p910_get_cycles, > + .mask = CLOCKSOURCE_MASK(32), > + .shift = 20, > + .flags = CLOCK_SOURCE_IS_CONTINUOUS, > +}; > + > +static void __init w90p910_clocksource_init(unsigned int rate) > { > - w90x900_timer_setup(); > - setup_irq(IRQ_TIMER0, &w90x900_timer_irq); > + unsigned int val; > + > + __raw_writel(0xffffffff, REG_TICR1); > + > + val = __raw_readl(REG_TCSR1); > + val |= (COUNTEN | PERIOD); > + __raw_writel(val, REG_TCSR1); > + > + clocksource_w90p910.mult = > + clocksource_khz2mult((rate / 1000), clocksource_w90p910.shift); > + clocksource_register(&clocksource_w90p910); > +} > + > +static void __init w90p910_timer_init(void) > +{ > + struct clk *ck_ext = clk_get(NULL, "ext"); > + unsigned int rate; > + > + BUG_ON(IS_ERR(ck_ext)); > + > + rate = clk_get_rate(ck_ext); > + clk_put(ck_ext); > + rate = rate / (PRESCALE + 0x01); > + > + /* set a known state */ > + __raw_writel(0x00, REG_TCSR0); > + __raw_writel(0x00, REG_TCSR1); > + __raw_writel(RESETINT, REG_TISR); > + timer0_load = (rate / TICKS_PER_SEC); > + > + setup_irq(IRQ_TIMER0, &w90p910_timer0_irq); > + > + w90p910_clocksource_init(rate); > + w90p910_clockevents_init(rate); > } > > struct sys_timer w90x900_timer = { > - .init = w90x900_timer_init, > - .offset = w90x900_gettimeoffset, > - .resume = w90x900_timer_setup > + .init = w90p910_timer_init, > }; > diff --git a/arch/arm/mach-w90x900/w90p910.c b/arch/arm/mach-w90x900/w90p910.c > index 8444eab..d33723b 100644 > --- a/arch/arm/mach-w90x900/w90p910.c > +++ b/arch/arm/mach-w90x900/w90p910.c > @@ -76,6 +76,7 @@ static DEFINE_CLK(wdt, 26); > static DEFINE_CLK(gdma, 27); > static DEFINE_CLK(adc, 28); > static DEFINE_CLK(usi, 29); > +static DEFINE_CLK(ext, 0); > > static struct clk_lookup w90p910_clkregs[] = { > DEF_CLKLOOK(&clk_lcd, "w90p910-lcd", NULL), > @@ -97,6 +98,7 @@ static struct clk_lookup w90p910_clkregs[] = { > DEF_CLKLOOK(&clk_gdma, "w90p910-gdma", NULL), > DEF_CLKLOOK(&clk_adc, "w90p910-adc", NULL), > DEF_CLKLOOK(&clk_usi, "w90p910-spi", NULL), > + DEF_CLKLOOK(&clk_ext, NULL, "ext"), > }; > > /* Initial serial platform data */ > -- > 1.5.6.3 >
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