[PATCH]HRT support in Samsung S5P Platform
Ben Dooks
ben at simtec.co.uk
Tue Jul 20 20:36:00 EDT 2010
On 07/19/10 07:54, MADHAV SINGHCHAUHAN wrote:
> From: Madhav Singh<singh.madhav at samsung.com>
> Date: Mon, 19 Jul 2010 10:51:01 +0530
> Subject: [PATCH] HRT support in Samsung Tree
> This patch implements HRT support for Samsung plat-s5p.
> RTC has been used as CLOCKEVENT and SYSTIMER as CLOCKSOURCE.
>
> Signed-off-by: Madhav Chauhan<singh.madhav at samsung.com>
> Signed-off-by: Kyungmin Park<kyungmin.park at samsung.com>
> ---
> arch/arm/mach-s5pv210/Kconfig | 9 +
> arch/arm/mach-s5pv210/include/mach/map.h | 4 +
> arch/arm/plat-s5p/clock.c | 15 +
> arch/arm/plat-s5p/cpu.c | 8 +
> arch/arm/plat-s5p/hr-time-rtc.c | 470 +++++++++++++++++++++++
> arch/arm/plat-s5p/include/plat/regs-sys-timer.h | 63 +++
> arch/arm/plat-samsung/include/plat/map-base.h | 2 +
> 7 files changed, 571 insertions(+), 0 deletions(-)
> create mode 100644 arch/arm/plat-s5p/hr-time-rtc.c
> create mode 100644 arch/arm/plat-s5p/include/plat/regs-sys-timer.h
>
> diff --git a/arch/arm/mach-s5pv210/Kconfig b/arch/arm/mach-s5pv210/Kconfig
> index 631019a..9d8698e 100644
> --- a/arch/arm/mach-s5pv210/Kconfig
> +++ b/arch/arm/mach-s5pv210/Kconfig
> @@ -101,4 +101,13 @@ config MACH_SMDKC110
> Machine support for Samsung SMDKC110
> S5PC110(MCP) is one of package option of S5PV210
>
> +config MACH_S5PV210_HRT
> + bool "HRtimer and Dynamic Tick support"
> + select GENERIC_TIME
> + select GENERIC_CLOCKEVENTS
> + select HIGH_RES_TIMERS
> + default n
> + help
> + Support for HRtimer and Dynamic Tick system using RTC and SYSTEM timer
> +
> endif
> diff --git a/arch/arm/mach-s5pv210/include/mach/map.h b/arch/arm/mach-s5pv210/include/mach/map.h
> index 17687f0..fd8e504 100644
> --- a/arch/arm/mach-s5pv210/include/mach/map.h
> +++ b/arch/arm/mach-s5pv210/include/mach/map.h
> @@ -42,6 +42,10 @@
> #define S5P_PA_TIMER S5PV210_PA_TIMER
>
> #define S5PV210_PA_SYSTIMER (0xE2600000)
> +/*For RTC*/
> +#define S5PC11X_PA_RTC (0xE2800000)
> +#define S3C_PA_RTC S5PC11X_PA_RTC
> +
>
> #define S5PV210_PA_WATCHDOG (0xE2700000)
>
> diff --git a/arch/arm/plat-s5p/clock.c b/arch/arm/plat-s5p/clock.c
> index b5e2552..1e2a6f4 100644
> --- a/arch/arm/plat-s5p/clock.c
> +++ b/arch/arm/plat-s5p/clock.c
> @@ -89,6 +89,19 @@ struct clk clk_arm = {
> .ctrlbit = 0,
> };
>
> +/*For HRT*/
> +struct clk clk_ext_xtal_rtc = {
> + .name = "XrtcXTI",
> + .id = -1,
> + .rate = 32768,
> +};
> +
> +struct clk clk_ext_xtal_usb = {
> + .name = "XusbXTI",
> + .id = -1,
> + .rate = 24000000,
> +};
> +
> /* Possible clock sources for APLL Mux */
> static struct clk *clk_src_apll_list[] = {
> [0] =&clk_fin_apll,
> @@ -149,6 +162,8 @@ static struct clk *s5p_clks[] __initdata = {
> &clk_arm,
> &clk_vpll,
> &clk_xusbxti,
> + &clk_ext_xtal_usb,
> + &clk_ext_xtal_rtc,
I think you've invented clk_ext_xtal_usb which is already being used
to feed the usb phyd.
Do we need the XrtcXTI as iirc, this has to be 32.768KHz?
> };
>
> void __init s5p_register_clocks(unsigned long xtal_freq)
> diff --git a/arch/arm/plat-s5p/cpu.c b/arch/arm/plat-s5p/cpu.c
> index 75cb8c3..83ae862 100644
> --- a/arch/arm/plat-s5p/cpu.c
> +++ b/arch/arm/plat-s5p/cpu.c
> @@ -104,6 +104,14 @@ static struct map_desc s5p_iodesc[] __initdata = {
> .length = SZ_4K,
> .type = MT_DEVICE,
> },
> +#if defined(CONFIG_MACH_S5PV210_HRT)
> + {
> + .virtual = (unsigned long)S3C_VA_RTC,
> + .pfn = __phys_to_pfn(S3C_PA_RTC),
> + .length = SZ_4K,
> + .type = MT_DEVICE,
> + },
> +#endif
> };
>
> /* read cpu identification code */
> diff --git a/arch/arm/plat-s5p/hr-time-rtc.c b/arch/arm/plat-s5p/hr-time-rtc.c
> new file mode 100644
> index 0000000..8decf4e
> --- /dev/null
> +++ b/arch/arm/plat-s5p/hr-time-rtc.c
> @@ -0,0 +1,470 @@
> +/*
> + * linux/arch/arm/plat-s5p/hr-time-rtc.c
> + *
> + * S5PC11X Timers
> + *
> + * Copyright (c) 2006 Samsung Electronics
> + * Copyright (c) 2010 Samsung Electronics Madhav Chauhan<singh.madhav at samsung.com>
> + *
> + *
> + * S5PC11X (and compatible) HRT support using RTC and SYSTEM TIMER
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + */
> +
> +#include<linux/kernel.h>
> +#include<linux/init.h>
> +#include<linux/delay.h>
> +#include<linux/interrupt.h>
> +#include<linux/sched.h>
> +#include<linux/spinlock.h>
> +#include<linux/clk.h>
> +#include<linux/err.h>
> +#include<linux/clocksource.h>
> +#include<linux/clockchips.h>
> +#include<linux/io.h>
> +#include<asm/system.h>
> +#include<mach/hardware.h>
> +#include<asm/irq.h>
> +#include<asm/mach/irq.h>
> +#include<asm/mach/time.h>
> +#include<asm/mach-types.h>
> +#include<mach/map.h>
> +#include<plat/regs-timer.h>
> +#include<plat/regs-rtc.h>
> +#include<plat/regs-sys-timer.h>
> +#include<mach/regs-irq.h>
> +#include<mach/tick.h>
> +#include<plat/clock.h>
> +#include<plat/cpu.h>
> +
> +/*For SCHED_CLOCK*/
> +static unsigned long long time_stamp;
> +static unsigned long long s5pc11x_sched_timer_overflows;
> +static unsigned long long old_overflows;
> +static cycle_t last_ticks;
> +
> +/* Sched timer interrupt is not processed right after
> + * timer counter expired
> + */
> +static unsigned int pending_irq;
> +
> +/* sched_timer_running
> + * 0 : sched timer stopped or not initialized
> + * 1 : sched timer started
> + */
> +static unsigned int sched_timer_running;
> +
> +void __iomem *rtc_base = S3C_VA_RTC;
> +static struct clk *clk_event;
> +static struct clk *clk_sched;
> +static int tick_timer_mode; /* 0: oneshot, 1: autoreload */
> +
> +#define RTC_CLOCK (32768)
> +#define RTC_DEFAULT_TICK ((RTC_CLOCK / HZ) - 1)
> +
> +/*
> + * Helper functions
> + * s5pc11x_systimer_read() : Read from System timer register
> + * s5pc11x_systimer_write(): Write to System timer register
> + *
> + */
> +static unsigned int s5pc11x_systimer_read(unsigned int *reg_offset)
> +{
> + return __raw_readl(reg_offset);
> +}
> +
> +static unsigned int s5pc11x_systimer_write(unsigned int *reg_offset,
> + unsigned int value)
> +{
> + unsigned int temp_regs;
> +
> + __raw_writel(value, reg_offset);
> +
> + if (reg_offset == S3C_SYSTIMER_TCON) {
> + while (!(__raw_readl(S3C_SYSTIMER_INT_CSTAT)&
> + S3C_SYSTIMER_INT_TCON));
> + temp_regs = __raw_readl(S3C_SYSTIMER_INT_CSTAT);
> + temp_regs |= S3C_SYSTIMER_INT_TCON;
> + __raw_writel(temp_regs, S3C_SYSTIMER_INT_CSTAT);
> +
> + } else if (reg_offset == S3C_SYSTIMER_ICNTB) {
> + while (!(__raw_readl(S3C_SYSTIMER_INT_CSTAT)&
> + S3C_SYSTIMER_INT_ICNTB));
> + temp_regs = __raw_readl(S3C_SYSTIMER_INT_CSTAT);
> + temp_regs |= S3C_SYSTIMER_INT_ICNTB;
> + __raw_writel(temp_regs, S3C_SYSTIMER_INT_CSTAT);
> +
> + } else if (reg_offset == S3C_SYSTIMER_TCNTB) {
> + while (!(__raw_readl(S3C_SYSTIMER_INT_CSTAT)&
> + S3C_SYSTIMER_INT_TCNTB));
> + temp_regs = __raw_readl(S3C_SYSTIMER_INT_CSTAT);
> + temp_regs |= S3C_SYSTIMER_INT_TCNTB;
> + __raw_writel(temp_regs, S3C_SYSTIMER_INT_CSTAT);
> + }
> +
> + return 0;
> +}
> +
> +static void s5pc11x_rtc_set_tick(int enabled)
> +{
> + unsigned int tmp;
> +
> + tmp = __raw_readl(rtc_base + S3C2410_RTCCON)& ~S3C_RTCCON_TICEN;
> + if (enabled)
> + tmp |= S3C_RTCCON_TICEN;
> + __raw_writel(tmp, rtc_base + S3C2410_RTCCON);
> +}
> +
> +static void s5pc11x_tick_timer_setup(void);
> +
> +static void s5pc11x_tick_timer_start(unsigned long load_val,
> + int autoreset)
> +{
> + unsigned int tmp;
> +
> + tmp = __raw_readl(rtc_base + S3C2410_RTCCON)&
> + ~(S3C_RTCCON_TICEN | S3C2410_RTCCON_RTCEN);
> + __raw_writel(tmp, rtc_base + S3C2410_RTCCON);
> +
> + __raw_writel(load_val, rtc_base + S3C2410_TICNT);
> +
> + tmp |= S3C_RTCCON_TICEN;
> +
> + __raw_writel(tmp, rtc_base + S3C2410_RTCCON);
> +}
> +
> +static void s5pc11x_tick_timer_stop(void)
> +{
> + unsigned int tmp;
> +
> + tmp = __raw_readl(rtc_base + S3C2410_RTCCON)&
> + ~(S3C_RTCCON_TICEN | S3C2410_RTCCON_RTCEN);
> +
> + __raw_writel(tmp, rtc_base + S3C2410_RTCCON);
> +
> +}
Will have to think about the cross usage against the
rtc driver.
> +static void s5pc11x_sched_timer_start(unsigned long load_val,
> + int autoreset)
> +{
> + unsigned long tcon;
> + unsigned long tcnt;
> + unsigned long tcfg;
> +
> + /* clock configuration setting and enable */
> + struct clk *clk;
> +
> + tcnt = TICK_MAX; /* default value for tcnt */
> +
> + /* initialize system timer clock */
> + tcfg = s5pc11x_systimer_read(S3C_SYSTIMER_TCFG);
> +
> + tcfg&= ~S3C_SYSTIMER_TCLK_MASK;
> + tcfg |= S3C_SYSTIMER_TCLK_USB;
> +
> + s5pc11x_systimer_write(S3C_SYSTIMER_TCFG, tcfg);
> +
> + /* TCFG must not be changed at run-time.
> + * If you want to change TCFG, stop timer(TCON[0] = 0)
> + */
> + s5pc11x_systimer_write(S3C_SYSTIMER_TCON, 0);
> +
> + /* read the current timer configuration bits */
> + tcon = s5pc11x_systimer_read(S3C_SYSTIMER_TCON);
> + tcfg = s5pc11x_systimer_read(S3C_SYSTIMER_TCFG);
> +
> + clk = clk_get(NULL, "systimer");
> + if (IS_ERR(clk))
> + panic("failed to get clock[%s] for system timer", "systimer");
> +
> + clk_enable(clk);
> +
> + clk_put(clk);
> +
> + tcfg&= ~S3C_SYSTIMER_TCLK_MASK;
> + tcfg |= S3C_SYSTIMER_TCLK_USB;
> + tcfg&= ~S3C_SYSTIMER_PRESCALER_MASK;
> +
> + /* check to see if timer is within 16bit range... */
> + if (tcnt> TICK_MAX) {
> + panic("setup_timer: cannot configure timer!");
> + return;
> + }
> +
> + s5pc11x_systimer_write(S3C_SYSTIMER_TCFG, tcfg);
> +
> + s5pc11x_systimer_write(S3C_SYSTIMER_TCNTB, tcnt);
> +
> + /* set timer con */
> + tcon = S3C_SYSTIMER_INT_AUTO | S3C_SYSTIMER_START |
> + S3C_SYSTIMER_AUTO_RELOAD;
> + s5pc11x_systimer_write(S3C_SYSTIMER_TCON, tcon);
> +
> + tcon |= S3C_SYSTIMER_INT_START;
> + s5pc11x_systimer_write(S3C_SYSTIMER_TCON, tcon);
> +
> + /* Interrupt Start and Enable */
> + s5pc11x_systimer_write(S3C_SYSTIMER_INT_CSTAT,
> + (S3C_SYSTIMER_INT_ICNTEIE |
> + S3C_SYSTIMER_INT_EN));
> + sched_timer_running = 1;
> +}
> +
> +/*
> + * RTC tick : count down to zero, interrupt, reload
> + */
> +static int s5pc11x_tick_set_next_event(unsigned long cycles,
> + struct clock_event_device *evt)
> +{
> + if (cycles == 0) /* Should be larger than 0 */
> + cycles = 1;
> + s5pc11x_tick_timer_start(cycles, 0);
> + return 0;
> +}
> +
> +static void s5pc11x_tick_set_mode(enum clock_event_mode mode,
> + struct clock_event_device *evt)
> +{
> + switch (mode) {
> + case CLOCK_EVT_MODE_PERIODIC:
> + tick_timer_mode = 1;
> + break;
> + case CLOCK_EVT_MODE_ONESHOT:
> + s5pc11x_tick_timer_stop();
> + tick_timer_mode = 0;
> + break;
> + case CLOCK_EVT_MODE_UNUSED:
> + case CLOCK_EVT_MODE_SHUTDOWN:
> + /* Sched timer stopped */
> + sched_timer_running = 0;
> + /* Reset sched_clock variables after sleep/wakeup */
> + last_ticks = 0;
> + s5pc11x_sched_timer_overflows = 0;
> + old_overflows = 0;
> + pending_irq = 0;
> + break;
> + case CLOCK_EVT_MODE_RESUME:
> + s5pc11x_tick_timer_setup();
> + s5pc11x_sched_timer_start(~0, 1);
> + break;
> + }
> +}
> +
> +static struct clock_event_device clockevent_tick_timer = {
> + .name = "S5PC110 event timer",
> + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
> + .shift = 32,
> + .set_next_event = s5pc11x_tick_set_next_event,
> + .set_mode = s5pc11x_tick_set_mode,
> +};
> +
> +irqreturn_t s5pc11x_tick_timer_interrupt(int irq, void *dev_id)
> +{
> + struct clock_event_device *evt =&clockevent_tick_timer;
> +
> + __raw_writel(S3C_INTP_TIC, rtc_base + S3C_INTP);
> + /* In case of oneshot mode */
> + if (tick_timer_mode == 0)
> + s5pc11x_tick_timer_stop();
> +
> + evt->event_handler(evt);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static struct irqaction s5pc11x_tick_timer_irq = {
> + .name = "rtc-tick",
> + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
> + .handler = s5pc11x_tick_timer_interrupt,
> +};
> +
> +static void s5pc11x_init_dynamic_tick_timer(unsigned long rate)
> +{
> + tick_timer_mode = 1;
> +
> + s5pc11x_tick_timer_stop();
> +
> + s5pc11x_tick_timer_start((rate / HZ) - 1, 1);
> +
> + clockevent_tick_timer.mult = div_sc(rate, NSEC_PER_SEC,
> + clockevent_tick_timer.shift);
> + clockevent_tick_timer.max_delta_ns =
> + clockevent_delta2ns(-1,&clockevent_tick_timer);
> + clockevent_tick_timer.min_delta_ns =
> + clockevent_delta2ns(1,&clockevent_tick_timer);
> +
> + clockevent_tick_timer.cpumask = cpumask_of(0);
> + clockevents_register_device(&clockevent_tick_timer);
> +
> + printk(KERN_INFO "mult[%u]\n", clockevent_tick_timer.mult);
> + printk(KERN_INFO "max_delta_ns[%u]\n", clockevent_tick_timer.max_delta_ns);
> + printk(KERN_INFO "min_delta_ns[%u]\n", clockevent_tick_timer.min_delta_ns);
> + printk(KERN_INFO "rate[%lu]\n", rate);
> + printk(KERN_INFO "HZ[%d]\n", HZ);
> +}
> +
> +
> +/*
> + * ---------------------------------------------------------------------------
> + * SYSTEM TIMER ... free running 32-bit clock source and scheduler clock
> + * ---------------------------------------------------------------------------
> + */
> +irqreturn_t s5pc11x_sched_timer_interrupt(int irq, void *dev_id)
> +{
> + volatile unsigned int temp_cstat;
> +
> + temp_cstat = s5pc11x_systimer_read(S3C_SYSTIMER_INT_CSTAT);
> + temp_cstat |= S3C_SYSTIMER_INT_STATS;
> +
> + s5pc11x_systimer_write(S3C_SYSTIMER_INT_CSTAT, temp_cstat);
> +
> + if (unlikely(pending_irq))
> + pending_irq = 0;
> + else
> + s5pc11x_sched_timer_overflows++;
> +
> + return IRQ_HANDLED;
> +}
> +
> +struct irqaction s5pc11x_systimer_irq = {
> + .name = "System timer",
> + .flags = IRQF_DISABLED ,
> + .handler = s5pc11x_sched_timer_interrupt,
> +};
> +
> +
> +static cycle_t s5pc11x_sched_timer_read(void)
> +{
> + return (cycle_t)~__raw_readl(S3C_SYSTIMER_TCNTO);
> +}
> +
> +struct clocksource clocksource_s5pc11x = {
> + .name = "clock_source_systimer",
> + .rating = 300,
> + .read = s5pc11x_sched_timer_read,
> + .mask = CLOCKSOURCE_MASK(32),
> + .shift = 20,
> + .flags = CLOCK_SOURCE_IS_CONTINUOUS,
> +};
> +
> +static void s5pc11x_init_clocksource(unsigned long rate)
> +{
> + static char err[] __initdata = KERN_ERR
> + "%s: can't register clocksource!\n";
yuck
> + clocksource_s5pc11x.mult
> + = clocksource_khz2mult(rate/1000, clocksource_s5pc11x.shift);
> +
> +
> + s5pc11x_sched_timer_start(~0, 1);
> +
> + if (clocksource_register(&clocksource_s5pc11x))
> + printk(err, clocksource_s5pc11x.name);
> +}
> +
> +/*
> + * Returns current time from boot in nsecs. It's OK for this to wrap
> + * around for now, as it's just a relative time stamp.
> + */
> +unsigned long long sched_clock(void)
> +{
> + unsigned long irq_flags;
> + cycle_t ticks, elapsed_ticks = 0;
> + unsigned long long increment = 0;
> + unsigned int overflow_cnt = 0;
> +
> + local_irq_save(irq_flags);
> +
> + if (likely(sched_timer_running)) {
> + overflow_cnt = (s5pc11x_sched_timer_overflows - old_overflows);
> +
> + ticks = s5pc11x_sched_timer_read();
> +
> + if (overflow_cnt) {
> + increment = (overflow_cnt - 1) *
> + (clocksource_cyc2ns(clocksource_s5pc11x.mask,
> + clocksource_s5pc11x.mult, clocksource_s5pc11x.shift));
> + elapsed_ticks = (clocksource_s5pc11x.mask - last_ticks) + ticks;
> + } else {
> + if (unlikely(last_ticks> ticks)) {
> + pending_irq = 1;
> + elapsed_ticks = (clocksource_s5pc11x.mask - last_ticks) + ticks;
> + s5pc11x_sched_timer_overflows++;
> + } else {
> + elapsed_ticks = (ticks - last_ticks);
> + }
> + }
> +
> + time_stamp += (clocksource_cyc2ns(elapsed_ticks, clocksource_s5pc11x.mult, clocksource_s5pc11x.shift) + increment);
> +
> + old_overflows = s5pc11x_sched_timer_overflows;
> + last_ticks = ticks;
> + }
> + local_irq_restore(irq_flags);
> +
> + return time_stamp;
> +}
> +
> +/*
> + * Event/Sched Timer initialization
> + */
> +static void s5pc11x_timer_setup(void)
> +{
> + unsigned long rate;
> + /* Setup event timer using XrtcXTI */
> + if (clk_event == NULL)
> + clk_event = clk_get(NULL, "XrtcXTI");
> + if (IS_ERR(clk_event))
> + panic("failed to get clock for event timer");
> + rate = clk_get_rate(clk_event);
> + s5pc11x_init_dynamic_tick_timer(rate);
> +
> + /* Setup sched-timer using XusbXTI */
> + if (clk_sched == NULL)
> + clk_sched = clk_get(NULL, "XusbXTI");
> + if (IS_ERR(clk_sched))
> + panic("failed to get clock for sched-timer");
> + rate = clk_get_rate(clk_sched);
> + s5pc11x_init_clocksource(rate);
> +}
> +
> +static void s5pc11x_tick_timer_setup(void)
> +{
> + unsigned long rate;
> +
> + rate = clk_get_rate(clk_event);
> + s5pc11x_tick_timer_start((rate / HZ) - 1, 1);
> +}
> +
> +static void __init s5pc11x_timer_init(void)
> +{
> + /* Initialize variables before starting each timers */
> + last_ticks = 0;
> + s5pc11x_sched_timer_overflows = 0;
> + old_overflows = 0;
> + time_stamp = 0;
> + sched_timer_running = 0;
> + pending_irq = 0;
> + s5pc11x_timer_setup();
> + setup_irq(IRQ_RTC_TIC,&s5pc11x_tick_timer_irq);
> + setup_irq(IRQ_SYSTIMER,&s5pc11x_systimer_irq);
> +}
> +
> +
> +struct sys_timer s3c24xx_timer = {
> + .init = s5pc11x_timer_init,
> +};
> +
--
Ben Dooks, Design & Software Engineer, Simtec Electronics
http://www.simtec.co.uk/
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