Hello, I've following comments: > -----Original Message----- > From: linux-samsung-soc-owner@xxxxxxxxxxxxxxx [mailto:linux-samsung- > soc-owner@xxxxxxxxxxxxxxx] On Behalf Of Kukjin Kim > Sent: Friday, May 14, 2010 10:52 AM > To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-samsung- > soc@xxxxxxxxxxxxxxx > Cc: ben-linux@xxxxxxxxx; Jongpill Lee; Jongpill Lee; Kukjin Kim > Subject: [PATCH v2] ARM: S5P: Add System Timer > > From: Jongpill Lee <boyko@xxxxxxxxxxx> > > This patch addes system timer for Samsung S5P series SoCs > > Signed-off-by: Jongpill Lee <boyko.lee@xxxxxxxxxxx> > Signed-off-by: Kukjin Kim <kgene.kim@xxxxxxxxxxx> > --- > arch/arm/mach-s5p6442/include/mach/tick.h | 6 + > arch/arm/mach-s5p6442/mach-smdk6442.c | 2 +- > arch/arm/mach-s5pv210/include/mach/tick.h | 6 + > arch/arm/mach-s5pv210/mach-smdkc110.c | 2 +- > arch/arm/mach-s5pv210/mach-smdkv210.c | 2 +- > arch/arm/plat-s5p/Kconfig | 7 + > arch/arm/plat-s5p/Makefile | 1 + > arch/arm/plat-s5p/include/plat/regs-systimer.h | 75 ++++++ > arch/arm/plat-s5p/s5p-systimer.c | 287 > ++++++++++++++++++++++++ > arch/arm/plat-samsung/include/plat/cpu.h | 3 + > 10 files changed, 388 insertions(+), 3 deletions(-) > create mode 100644 arch/arm/plat-s5p/include/plat/regs-systimer.h > create mode 100644 arch/arm/plat-s5p/s5p-systimer.c > > diff --git a/arch/arm/mach-s5p6442/include/mach/tick.h b/arch/arm/mach- > s5p6442/include/mach/tick.h > index e1d4cab..1795b43 100644 > --- a/arch/arm/mach-s5p6442/include/mach/tick.h > +++ b/arch/arm/mach-s5p6442/include/mach/tick.h > @@ -21,6 +21,12 @@ static inline u32 s3c24xx_ostimer_pending(void) > return pend & (1 << (IRQ_TIMER4_VIC - S5P_IRQ_VIC0(0))); > } > > +static inline u32 s5p_ostimer_pending(void) > +{ > + u32 pend = __raw_readl(VA_VIC0 + VIC_RAW_STATUS); > + return pend & (1 << (IRQ_SYSTIMER - S5P_IRQ_VIC0(0))); > +} > + > #define TICK_MAX (0xffffffff) > > #endif /* __ASM_ARCH_TICK_H */ > diff --git a/arch/arm/mach-s5p6442/mach-smdk6442.c b/arch/arm/mach- > s5p6442/mach-smdk6442.c > index 0d63371..6c8728b 100644 > --- a/arch/arm/mach-s5p6442/mach-smdk6442.c > +++ b/arch/arm/mach-s5p6442/mach-smdk6442.c > @@ -87,5 +87,5 @@ MACHINE_START(SMDK6442, "SMDK6442") > .init_irq = s5p6442_init_irq, > .map_io = smdk6442_map_io, > .init_machine = smdk6442_machine_init, > - .timer = &s3c24xx_timer, > + .timer = &s5p_systimer, > MACHINE_END > diff --git a/arch/arm/mach-s5pv210/include/mach/tick.h b/arch/arm/mach- > s5pv210/include/mach/tick.h > index 7993b36..9fc5a8d 100644 > --- a/arch/arm/mach-s5pv210/include/mach/tick.h > +++ b/arch/arm/mach-s5pv210/include/mach/tick.h > @@ -21,6 +21,12 @@ static inline u32 s3c24xx_ostimer_pending(void) > return pend & (1 << (IRQ_TIMER4_VIC - S5P_IRQ_VIC0(0))); > } > > +static inline u32 s5p_ostimer_pending(void) > +{ > + u32 pend = __raw_readl(VA_VIC0 + VIC_RAW_STATUS); > + return pend & (1 << (IRQ_SYSTIMER - S5P_IRQ_VIC0(0))); > +} > + > #define TICK_MAX (0xffffffff) > > #endif /* __ASM_ARCH_TICK_H */ > diff --git a/arch/arm/mach-s5pv210/mach-smdkc110.c b/arch/arm/mach- > s5pv210/mach-smdkc110.c > index ab4869d..b520817 100644 > --- a/arch/arm/mach-s5pv210/mach-smdkc110.c > +++ b/arch/arm/mach-s5pv210/mach-smdkc110.c > @@ -94,5 +94,5 @@ MACHINE_START(SMDKC110, "SMDKC110") > .init_irq = s5pv210_init_irq, > .map_io = smdkc110_map_io, > .init_machine = smdkc110_machine_init, > - .timer = &s3c24xx_timer, > + .timer = &s5p_systimer, > MACHINE_END > diff --git a/arch/arm/mach-s5pv210/mach-smdkv210.c b/arch/arm/mach- > s5pv210/mach-smdkv210.c > index a278832..2a29d47 100644 > --- a/arch/arm/mach-s5pv210/mach-smdkv210.c > +++ b/arch/arm/mach-s5pv210/mach-smdkv210.c > @@ -94,5 +94,5 @@ MACHINE_START(SMDKV210, "SMDKV210") > .init_irq = s5pv210_init_irq, > .map_io = smdkv210_map_io, > .init_machine = smdkv210_machine_init, > - .timer = &s3c24xx_timer, > + .timer = &s5p_systimer, > MACHINE_END > diff --git a/arch/arm/plat-s5p/Kconfig b/arch/arm/plat-s5p/Kconfig > index d400a6a..e152bbc 100644 > --- a/arch/arm/plat-s5p/Kconfig > +++ b/arch/arm/plat-s5p/Kconfig > @@ -23,3 +23,10 @@ config PLAT_S5P > select SAMSUNG_IRQ_UART > help > Base platform code for Samsung's S5P series SoC. > + > +config S5P_SYSTIMER > + bool > + depends on (ARCH_S5P6442 || ARCH_S5PV210) > + default y > + help > + Support System Timer for S5P Series > diff --git a/arch/arm/plat-s5p/Makefile b/arch/arm/plat-s5p/Makefile > index 7f44678..dbc6595 100644 > --- a/arch/arm/plat-s5p/Makefile > +++ b/arch/arm/plat-s5p/Makefile > @@ -17,3 +17,4 @@ obj-y += cpu.o > obj-y += clock.o > obj-y += irq.o > obj-y += setup-i2c0.o > +obj-$(CONFIG_S5P_SYSTIMER) += s5p-systimer.o > diff --git a/arch/arm/plat-s5p/include/plat/regs-systimer.h > b/arch/arm/plat-s5p/include/plat/regs-systimer.h > new file mode 100644 > index 0000000..61f1282 > --- /dev/null > +++ b/arch/arm/plat-s5p/include/plat/regs-systimer.h > @@ -0,0 +1,75 @@ > +/* linux/arch/arm/plat-s5p/include/plat/regs-systimer.h > + * > + * Copyright (c) 2010 Samsung Electronics Co., Ltd. > + * http://www.samsung.com/ > + * > + * S5P System Timer Driver Header information > + * > + * This program is free software; you can redistribute it and/or > modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > +*/ > + > +#ifndef __ASM_PLAT_REGS_SYSTIMER_H > +#define __ASM_PLAT_REGS_SYSTIMER_H __FILE__ > + > +#define S5P_SYSTIMERREG(x) (S5P_VA_SYSTIMER + (x)) > + > +#define S5P_SYSTIMER_TCFG S5P_SYSTIMERREG(0x00) > +#define S5P_SYSTIMER_TCON S5P_SYSTIMERREG(0x04) > +#define S5P_SYSTIMER_TICNTB S5P_SYSTIMERREG(0x08) > +#define S5P_SYSTIMER_TICNTO S5P_SYSTIMERREG(0x0c) > +#define S5P_SYSTIMER_TFCNTB S5P_SYSTIMERREG(0x10) > +#define S5P_SYSTIMER_ICNTB S5P_SYSTIMERREG(0x18) > +#define S5P_SYSTIMER_ICNTO S5P_SYSTIMERREG(0x1c) > +#define S5P_SYSTIMER_INT_CSTAT S5P_SYSTIMERREG(0x20) > + > +/* Value for TCFG */ > + > +#define S5P_SYSTIMER_SWRST (1 << 16) > + > +#define S5P_SYSTIMER_DIV_GEN (0 << 15) > +#define S5P_SYSTIMER_DIV_RTC (1 << 15) > + > +#define S5P_SYSTIMER_TICK_INT (0 << 14) > +#define S5P_SYSTIMER_TICK_FRA (1 << 14) > + > +#define S5P_SYSTIMER_TCLK_MASK (3 << 12) > +#define S5P_SYSTIMER_TCLK_XXTI (0 << 12) > +#define S5P_SYSTIMER_TCLK_RTC (1 << 12) > +#define S5P_SYSTIMER_TCLK_USB (2 << 12) > +#define S5P_SYSTIMER_TCLK_PCLK (3 << 12) > + > +#define S5P_SYSTIMER_DIV_MASK (7 << 8) > +#define S5P_SYSTIMER_DIV_1 (0 << 8) > +#define S5P_SYSTIMER_DIV_2 (1 << 8) > +#define S5P_SYSTIMER_DIV_4 (2 << 8) > +#define S5P_SYSTIMER_DIV_8 (3 << 8) > +#define S5P_SYSTIMER_DIV_16 (4 << 8) > + > +#define S5P_SYSTIMER_TARGET_HZ 1000 > +#define S5P_SYSTIMER_PRESCALER 5 > +#define S5P_SYSTIMER_PRESCALER_MASK (0x3f << 0) > + > +/* value for TCON */ > + > +#define S5P_SYSTIMER_INT_AUTO (1 << 5) > +#define S5P_SYSTIMER_INT_IMM (1 << 4) > +#define S5P_SYSTIMER_INT_START (1 << 3) > +#define S5P_SYSTIMER_START (1 << 0) > + > +/* Value for INT_CSTAT */ > + > +#define S5P_SYSTIMER_INT_TWIE (1 << 10) > +#define S5P_SYSTIMER_INT_IWIE (1 << 9) > +#define S5P_SYSTIMER_INT_TFWIE (1 << 8) > +#define S5P_SYSTIMER_INT_TIWIE (1 << 7) > +#define S5P_SYSTIMER_INT_ICNTEIE (1 << 6) > +#define S5P_SYSTIMER_INT_TCON (1 << 5) > +#define S5P_SYSTIMER_INT_ICNTB (1 << 4) > +#define S5P_SYSTIMER_INT_TFCNTB (1 << 3) > +#define S5P_SYSTIMER_INT_TICNTB (1 << 2) > +#define S5P_SYSTIMER_INT_INTCNT (1 << 1) > +#define S5P_SYSTIMER_INT_INTENABLE (1 << 0) > + > +#endif /* __ASM_PLAT_REGS_SYSTIMER_H */ > diff --git a/arch/arm/plat-s5p/s5p-systimer.c b/arch/arm/plat-s5p/s5p- > systimer.c > new file mode 100644 > index 0000000..f0e4ec8 > --- /dev/null > +++ b/arch/arm/plat-s5p/s5p-systimer.c > @@ -0,0 +1,287 @@ > +/* linux/arch/arm/plat-s5p/s5p-systimer.c > + * > + * Copyright (c) 2010 Samsung Electronics Co., Ltd. > + * http://www.samsung.com/ > + * > + * S5P System Timer > + * > + * Based on linux/arch/arm/plat-samsung/time.c > + * > + * This program is free software; you can redistribute it and/or > modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > +*/ > + > +#include <linux/kernel.h> > +#include <linux/sched.h> > +#include <linux/init.h> > +#include <linux/errno.h> > +#include <linux/interrupt.h> > +#include <linux/irq.h> > +#include <linux/err.h> > +#include <linux/clk.h> > +#include <linux/io.h> > + > +#include <asm/system.h> > +#include <asm/mach-types.h> > + > +#include <asm/irq.h> > +#include <asm/mach/time.h> > + > +#include <mach/map.h> > +#include <mach/regs-irq.h> > +#include <mach/tick.h> > + > +#include <plat/regs-systimer.h> > +#include <plat/clock.h> > +#include <plat/cpu.h> > + > +#include <mach/regs-clock.h> > + > +static unsigned long timer_startval; > +static unsigned long timer_usec_ticks; > +static unsigned long timer_icnt; > + > +#define TICK_MAX (0xffffffff) > +#define TIMER_USEC_SHIFT 16 > + > +static unsigned int systimer_write_done(unsigned int value) > +{ > + unsigned int cnt; > + unsigned int tmp_reg; > + > + cnt = 1000; > + > + do { > + if (__raw_readl(S5P_SYSTIMER_INT_CSTAT) & value) { > + tmp_reg = __raw_readl(S5P_SYSTIMER_INT_CSTAT); > + tmp_reg |= value; > + __raw_writel(tmp_reg , S5P_SYSTIMER_INT_CSTAT); > + > + return 0; > + } > + } while (--cnt > 0); > + > + printk(KERN_ERR "%s : %d : Timer Expired\n", __func__, value); > + > + return -ETIME; > +} > + > +static unsigned int s5p_systimer_write(void __iomem *reg, > + unsigned int value) > +{ > + unsigned int int_cstat; > + unsigned int ret = 0; > + > + __raw_writel(value, reg); > + > + int_cstat = __raw_readl(S5P_SYSTIMER_INT_CSTAT); > + > + if (reg == S5P_SYSTIMER_TCON) { > + if (int_cstat & S5P_SYSTIMER_INT_TWIE) > + ret = systimer_write_done(S5P_SYSTIMER_INT_TCON); > + > + } else if (reg == S5P_SYSTIMER_ICNTB) { > + if (int_cstat & S5P_SYSTIMER_INT_IWIE) > + ret = systimer_write_done(S5P_SYSTIMER_INT_ICNTB); > + > + } else if (reg == S5P_SYSTIMER_TFCNTB) { > + if (int_cstat & S5P_SYSTIMER_INT_TFWIE) > + ret = systimer_write_done(S5P_SYSTIMER_INT_TFCNTB); > + > + } else if (reg == S5P_SYSTIMER_TICNTB) { > + if (int_cstat & S5P_SYSTIMER_INT_TIWIE) > + ret = systimer_write_done(S5P_SYSTIMER_INT_TICNTB); > + } > + > + return ret; > +} > + > +/* > + * S5P has system timer to use as OS tick Timer. > + * System Timer provides two distincive feature. Accurate timer which > provides > + * exact 1ms time tick at any power mode except sleep mode. > + * interrupt interval without stopping reference tick timer. > + */ > + > +/* > + * timer_mask_usec_ticks > + * > + * given a clock and divisor, make the value to pass into > timer_ticks_to_usec > + * to scale the ticks into usecs > + */ > +static inline unsigned long timer_mask_usec_ticks(unsigned long > scaler, > + unsigned long pclk) > +{ > + unsigned long den = pclk / 1000; > + > + return ((1000 << TIMER_USEC_SHIFT) * scaler + (den >> 1)) / den; > +} > + > +/* > + * timer_ticks_to_usec > + * > + * convert timer ticks to usec. > + */ > +static inline unsigned long timer_ticks_to_usec(unsigned long ticks) > +{ > + unsigned long res; > + > + res = ticks * timer_usec_ticks; > + res += 1 << (TIMER_USEC_SHIFT - 4); /* round up slightly */ > + > + return res >> TIMER_USEC_SHIFT; > +} > + > +/* > + * Returns microsecond since last clock interrupt. Note that > interrupts > + * will have been disabled by do_gettimeoffset() > + * IRQs are disabled before entering here from do_gettimeofday() > + */ > +static unsigned long s5p_gettimeoffset(void) > +{ > + unsigned long tdone; > + unsigned long tval; > + unsigned long clk_tick_totcnt; > + > + clk_tick_totcnt = (timer_icnt + 1) * timer_startval; > + > + /* work out how many ticks have gone since last timer interrupt > */ > + tval = __raw_readl(S5P_SYSTIMER_ICNTO) * timer_startval; > + tval += __raw_readl(S5P_SYSTIMER_TICNTO); > + > + tdone = clk_tick_totcnt - tval; > + > + /* check to see if there is an interrupt pending */ > + if (s5p_ostimer_pending()) { > + /* re-read the timer, and try and fix up for the missed > + * interrupt. Note, the interrupt may go off before the > + * timer has re-loaded from wrapping. > + */ > + > + tval = __raw_readl(S5P_SYSTIMER_ICNTO) * timer_startval; > + tval += __raw_readl(S5P_SYSTIMER_TICNTO); > + > + tdone = clk_tick_totcnt - tval; > + > + if (tval != 0) > + tdone += clk_tick_totcnt; > + } > + > + return timer_ticks_to_usec(tdone); > +} > + > +/* > + * IRQ handler for the timer > + */ > +static irqreturn_t s5p_systimer_interrupt(int irq, void *dev_id) > +{ > + unsigned int temp_cstat; > + > + temp_cstat = __raw_readl(S5P_SYSTIMER_INT_CSTAT); > + temp_cstat |= S5P_SYSTIMER_INT_INTCNT; > + s5p_systimer_write(S5P_SYSTIMER_INT_CSTAT, temp_cstat); > + > + timer_tick(); > + > + return IRQ_HANDLED; > +} > + > +static struct irqaction s5p_systimer_irq = { > + .name = "S5P System Timer", > + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, > + .handler = s5p_systimer_interrupt, > +}; > + > +/* > + * Set up timer interrupt, and return the current time in seconds. > + */ > +static void s5p_systimer_setup(void) > +{ > + unsigned long tcon; > + unsigned long tcnt; > + unsigned long tcfg; > + unsigned long int_csata; > + > + /* clock configuration setting and enable */ > + unsigned long pclk; > + struct clk *clk; > + > + clk = clk_get(NULL, "systimer"); > + if (IS_ERR(clk)) > + panic("failed to get clock for system timer"); > + > + clk_enable(clk); > + > + pclk = clk_get_rate(clk); > + > + tcfg = __raw_readl(S5P_SYSTIMER_TCFG); > + tcfg |= S5P_SYSTIMER_SWRST; > + s5p_systimer_write(S5P_SYSTIMER_TCFG, tcfg); > + > + tcnt = TICK_MAX; /* default value for tcnt */ > + > + /* initialize system timer clock */ > + tcfg = __raw_readl(S5P_SYSTIMER_TCFG); > + > + tcfg &= ~S5P_SYSTIMER_TCLK_MASK; > + tcfg |= S5P_SYSTIMER_TCLK_PCLK; > + > + s5p_systimer_write(S5P_SYSTIMER_TCFG, tcfg); > + > + /* TCFG must not be changed at run-time. > + * If you want to change TCFG, stop timer(TCON[0] = 0) > + */ > + > + s5p_systimer_write(S5P_SYSTIMER_TCON, 0); > + > + /* read the current timer configuration bits */ > + tcon = __raw_readl(S5P_SYSTIMER_TCON); > + tcfg = __raw_readl(S5P_SYSTIMER_TCFG); > + > + /* configure clock tick */ > + timer_usec_ticks = timer_mask_usec_ticks(S5P_SYSTIMER_PRESCALER, > pclk); > + > + tcfg &= ~S5P_SYSTIMER_TCLK_MASK; > + tcfg |= S5P_SYSTIMER_TCLK_PCLK; Here the PCLK clock is used to feed the SYSTEM TIMER. Maybe it would be worth to use other (not system dependent and always available) clock source - for instance the main processor clock? And additionally it would be welcome to add this clock selection to the overall clock API? (with use of e.g. clock_set/get_parent) Is there any plan to do that? > + tcfg &= ~S5P_SYSTIMER_PRESCALER_MASK; > + tcfg |= S5P_SYSTIMER_PRESCALER - 1; > + > + tcnt = ((pclk / S5P_SYSTIMER_PRESCALER) / S5P_SYSTIMER_TARGET_HZ) > - 1; > + > + /* check to see if timer is within 16bit range... */ > + if (tcnt > TICK_MAX) { > + panic("setup_timer: HZ is too small, cannot configure > timer!"); > + return; > + } > + > + s5p_systimer_write(S5P_SYSTIMER_TCFG, tcfg); > + > + timer_startval = tcnt; > + s5p_systimer_write(S5P_SYSTIMER_TICNTB, tcnt); > + > + /* set Interrupt tick value */ > + timer_icnt = (S5P_SYSTIMER_TARGET_HZ / HZ) - 1; > + s5p_systimer_write(S5P_SYSTIMER_ICNTB, timer_icnt); > + > + tcon = (S5P_SYSTIMER_INT_AUTO | S5P_SYSTIMER_START > + | S5P_SYSTIMER_INT_START); > + s5p_systimer_write(S5P_SYSTIMER_TCON, tcon); > + > + /* Interrupt Start and Enable */ > + int_csata = __raw_readl(S5P_SYSTIMER_INT_CSTAT); > + int_csata |= (S5P_SYSTIMER_INT_ICNTEIE | > S5P_SYSTIMER_INT_INTENABLE); > + s5p_systimer_write(S5P_SYSTIMER_INT_CSTAT, int_csata); > +} > + > +static void __init s5p_systimer_init(void) > +{ > + s5p_systimer_setup(); > + setup_irq(IRQ_SYSTIMER, &s5p_systimer_irq); > +} > + > +struct sys_timer s5p_systimer = { > + .init = s5p_systimer_init, > + .offset = s5p_gettimeoffset, > + .resume = s5p_systimer_setup > +}; > diff --git a/arch/arm/plat-samsung/include/plat/cpu.h b/arch/arm/plat- > samsung/include/plat/cpu.h > index c54f318..d1ec201 100644 > --- a/arch/arm/plat-samsung/include/plat/cpu.h > +++ b/arch/arm/plat-samsung/include/plat/cpu.h > @@ -68,6 +68,9 @@ extern void s3c24xx_init_uartdevs(char *name, > struct sys_timer; > extern struct sys_timer s3c24xx_timer; > > +/* timer for s5p */ > +extern struct sys_timer s5p_systimer; > + > /* system device classes */ > > extern struct sysdev_class s3c2410_sysclass; > -- > 1.6.2.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux- > samsung-soc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html Best regards, Lukasz Majewski Samsung Poland R&D Center Platform Group -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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