[PATCH] ARM: S5P: Add System Timer
Kukjin Kim
kgene.kim at samsung.com
Mon Mar 29 22:29:45 EDT 2010
From: Jongpill Lee <boyko.lee at samsung.com>
This patch addes system timer for Samsung S5P series SoCs
Signed-off-by: Jongpill Lee <boyko.lee at samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim at samsung.com>
---
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-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/systimer-s5p.c | 298 ++++++++++++++++++++++++
arch/arm/plat-samsung/include/plat/cpu.h | 3 +
9 files changed, 398 insertions(+), 2 deletions(-)
create mode 100644 arch/arm/plat-s5p/include/plat/regs-systimer.h
create mode 100644 arch/arm/plat-s5p/systimer-s5p.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..825df9d 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-smdkv210.c b/arch/arm/mach-s5pv210/mach-smdkv210.c
index a278832..22ed209 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..a73fc56 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 SYSTIMER_S5P
+ 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 a7c54b3..ec28f1b 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_SYSTIMER_S5P) += systimer-s5p.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..937ec44
--- /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/systimer-s5p.c b/arch/arm/plat-s5p/systimer-s5p.c
new file mode 100644
index 0000000..66951c8
--- /dev/null
+++ b/arch/arm/plat-s5p/systimer-s5p.c
@@ -0,0 +1,298 @@
+/* linux/arch/arm/plat-s5p/systimer-s5p.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 {
+ cnt--;
+
+ 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_offset,
+ unsigned int value)
+{
+ unsigned int int_cstat;
+ unsigned int ret = 0;
+
+ int_cstat = __raw_readl(S5P_SYSTIMER_INT_CSTAT);
+
+ if (reg_offset == S5P_SYSTIMER_TCON) {
+ __raw_writel(value, reg_offset);
+
+ if (int_cstat & S5P_SYSTIMER_INT_TWIE)
+ ret = systimer_write_done(S5P_SYSTIMER_INT_TCON);
+
+ } else if (reg_offset == S5P_SYSTIMER_ICNTB) {
+ __raw_writel(value, reg_offset);
+
+ if (int_cstat & S5P_SYSTIMER_INT_IWIE)
+ ret = systimer_write_done(S5P_SYSTIMER_INT_ICNTB);
+
+ } else if (reg_offset == S5P_SYSTIMER_TFCNTB) {
+ __raw_writel(value, reg_offset);
+
+ if (int_cstat & S5P_SYSTIMER_INT_TFWIE)
+ ret = systimer_write_done(S5P_SYSTIMER_INT_TFCNTB);
+
+ } else if (reg_offset == S5P_SYSTIMER_TICNTB) {
+ __raw_writel(value, reg_offset);
+
+ if (int_cstat & S5P_SYSTIMER_INT_TIWIE)
+ ret = systimer_write_done(S5P_SYSTIMER_INT_TICNTB);
+ } else {
+ __raw_writel(value, reg_offset);
+ }
+
+ 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;
+ 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 d316b4a..6baa357 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
More information about the linux-arm-kernel
mailing list