[PATCH] ARM: S5PV310: Implement kernel timers using MCT
Kukjin Kim
kgene.kim at samsung.com
Wed Dec 22 06:27:01 EST 2010
From: Changhwan Youn <chaos.youn at samsung.com>
The Multi-Core Timer(MCT) of S5PV310 is designed for implementing
clock source timer and clock event timers. This patch implements
1 clock source timer with 64 bit free running counter of MCT and
2 clock event timers with two of 31-bit tick counters.
Signed-off-by: Changhwan Youn <chaos.youn at samsung.com>
Cc: Ben Dooks <ben-linux at fluff.org>
Cc: Russell King <rmk+kernel at arm.linux.org.uk>
Signed-off-by: Kukjin Kim <kgene.kim at samsung.com>
---
arch/arm/mach-s5pv310/Kconfig | 7 +
arch/arm/mach-s5pv310/Makefile | 8 +-
arch/arm/mach-s5pv310/include/mach/regs-mct.h | 47 ++++
arch/arm/mach-s5pv310/mct.c | 365 +++++++++++++++++++++++++
4 files changed, 426 insertions(+), 1 deletions(-)
create mode 100644 arch/arm/mach-s5pv310/include/mach/regs-mct.h
create mode 100644 arch/arm/mach-s5pv310/mct.c
diff --git a/arch/arm/mach-s5pv310/Kconfig b/arch/arm/mach-s5pv310/Kconfig
index e0cef3f..02d7b4d 100644
--- a/arch/arm/mach-s5pv310/Kconfig
+++ b/arch/arm/mach-s5pv310/Kconfig
@@ -14,6 +14,13 @@ config CPU_S5PV310
help
Enable S5PV310 CPU support
+config S5PV310_MCT
+ bool "Kernel timer support by MCT"
+ depends on !LOCAL_TIMERS
+ help
+ Use MCT (Multi Core Timer) as kernel timers
+ NOTE: Can not choose this with LOCAL_TIMERS
+
config S5PV310_DEV_PD
bool
help
diff --git a/arch/arm/mach-s5pv310/Makefile b/arch/arm/mach-s5pv310/Makefile
index e310609..08158e3 100644
--- a/arch/arm/mach-s5pv310/Makefile
+++ b/arch/arm/mach-s5pv310/Makefile
@@ -13,7 +13,13 @@ obj- :=
# Core support for S5PV310 system
obj-$(CONFIG_CPU_S5PV310) += cpu.o init.o clock.o irq-combiner.o
-obj-$(CONFIG_CPU_S5PV310) += setup-i2c0.o time.o gpiolib.o irq-eint.o
+obj-$(CONFIG_CPU_S5PV310) += setup-i2c0.o gpiolib.o irq-eint.o
+
+ifeq ($(CONFIG_S5PV310_MCT),y)
+obj-y += mct.o
+else
+obj-y += time.o
+endif
obj-$(CONFIG_SMP) += platsmp.o headsmp.o
obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
diff --git a/arch/arm/mach-s5pv310/include/mach/regs-mct.h b/arch/arm/mach-s5pv310/include/mach/regs-mct.h
new file mode 100644
index 0000000..1480e2a
--- /dev/null
+++ b/arch/arm/mach-s5pv310/include/mach/regs-mct.h
@@ -0,0 +1,47 @@
+/* arch/arm/mach-s5pv310/include/mach/regs-mct.h
+ *
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ *
+ * S5PV310 MCT(Multi-Core Timer) configutation
+ *
+ * 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_ARCH_REGS_MCT_H
+#define __ASM_ARCH_REGS_MCT_H __FILE__
+
+#include <mach/map.h>
+
+#define S5PV310_MCTREG(x) (S5P_VA_SYSTIMER + (x))
+
+#define S5PV310_MCT_G_CNT_L S5PV310_MCTREG(0x100)
+#define S5PV310_MCT_G_CNT_U S5PV310_MCTREG(0x104)
+#define S5PV310_MCT_G_CNT_WSTAT S5PV310_MCTREG(0x110)
+
+#define S5PV310_MCT_G_TCON S5PV310_MCTREG(0x240)
+
+#define S5PV310_MCT_G_WSTAT S5PV310_MCTREG(0x24C)
+
+#define S5PV310_MCT_L0_TCNTB S5PV310_MCTREG(0x300)
+#define S5PV310_MCT_L0_ICNTB S5PV310_MCTREG(0x308)
+#define S5PV310_MCT_L0_TCON S5PV310_MCTREG(0x320)
+
+#define S5PV310_MCT_L0_INT_CSTAT S5PV310_MCTREG(0x330)
+#define S5PV310_MCT_L0_INT_ENB S5PV310_MCTREG(0x334)
+#define S5PV310_MCT_L0_WSTAT S5PV310_MCTREG(0x340)
+
+#define S5PV310_MCT_L1_TCNTB S5PV310_MCTREG(0x400)
+#define S5PV310_MCT_L1_ICNTB S5PV310_MCTREG(0x408)
+#define S5PV310_MCT_L1_TCON S5PV310_MCTREG(0x420)
+#define S5PV310_MCT_L1_INT_CSTAT S5PV310_MCTREG(0x430)
+#define S5PV310_MCT_L1_INT_ENB S5PV310_MCTREG(0x434)
+#define S5PV310_MCT_L1_WSTAT S5PV310_MCTREG(0x440)
+
+#define MCT_L_TCON_INTERVAL_MODE (1 << 2)
+#define MCT_L_TCON_INT_START (1 << 1)
+#define MCT_L_TCON_TIMER_START (1 << 0)
+
+#endif /* __ASM_ARCH_REGS_MCT_H */
diff --git a/arch/arm/mach-s5pv310/mct.c b/arch/arm/mach-s5pv310/mct.c
new file mode 100644
index 0000000..2fe189c
--- /dev/null
+++ b/arch/arm/mach-s5pv310/mct.c
@@ -0,0 +1,365 @@
+/* linux/arch/arm/mach-s5pv310/mct.c
+ *
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ *
+ * S5PV310 MCT(Multi-Core Timer) support
+ *
+ * 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/sched.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+
+#include <mach/map.h>
+#include <mach/regs-mct.h>
+#include <asm/mach/time.h>
+
+static unsigned long clk_cnt_per_tick;
+static unsigned long clk_rate;
+
+enum mct_tick_type {
+ MCT_TICK0,
+ MCT_TICK1,
+};
+
+static void s5pv310_mct_write(unsigned int value, void *addr)
+{
+ void __iomem *stat_addr;
+ u32 mask;
+ u32 i;
+
+ __raw_writel(value, addr);
+
+ switch ((u32) addr) {
+ case (u32) S5PV310_MCT_G_TCON:
+ stat_addr = S5PV310_MCT_G_WSTAT;
+ mask = 1 << 16; /* G_WSTAT_TCON_STAT */
+ break;
+
+ case (u32) S5PV310_MCT_G_CNT_L:
+ stat_addr = S5PV310_MCT_G_CNT_WSTAT;
+ mask = 1 << 0; /* G_CNT_L_STAT */
+ break;
+
+ case (u32) S5PV310_MCT_G_CNT_U:
+ stat_addr = S5PV310_MCT_G_CNT_WSTAT;
+ mask = 1 << 1; /* G_CNT_U_STAT */
+ break;
+
+ case (u32) S5PV310_MCT_L0_TCON:
+ stat_addr = S5PV310_MCT_L0_WSTAT;
+ mask = 1 << 3; /* L_TCON_STAT */
+ break;
+
+ case (u32) S5PV310_MCT_L1_TCON:
+ stat_addr = S5PV310_MCT_L1_WSTAT;
+ mask = 1 << 3; /* L_TCON_STAT */
+ break;
+
+ case (u32) S5PV310_MCT_L0_TCNTB:
+ stat_addr = S5PV310_MCT_L0_WSTAT;
+ mask = 1 << 0; /* L_TCNTB_STAT */
+ break;
+
+ case (u32) S5PV310_MCT_L1_TCNTB:
+ stat_addr = S5PV310_MCT_L1_WSTAT;
+ mask = 1 << 0; /* L_TCNTB_STAT */
+ break;
+
+ case (u32) S5PV310_MCT_L0_ICNTB:
+ stat_addr = S5PV310_MCT_L0_WSTAT;
+ mask = 1 << 1; /* L_ICNTB_STAT */
+ break;
+
+ case (u32) S5PV310_MCT_L1_ICNTB:
+ stat_addr = S5PV310_MCT_L1_WSTAT;
+ mask = 1 << 1; /* L_ICNTB_STAT */
+ break;
+
+ default:
+ return;
+ }
+
+ /* Wait maximum 1 ms until written values are applied */
+ for (i = 0; i < loops_per_jiffy / 1000 * HZ; i++)
+ if (__raw_readl(stat_addr) & mask) {
+ __raw_writel(mask, stat_addr);
+ return;
+ }
+
+ panic("MCT hangs after writing %d (addr:0x%08x)\n", value, (u32)addr);
+}
+
+static void s5pv310_mct_tick_stop(enum mct_tick_type type)
+{
+ unsigned long tmp;
+ void __iomem *addr;
+
+ if (type == MCT_TICK0)
+ addr = S5PV310_MCT_L0_TCON;
+ else
+ addr = S5PV310_MCT_L1_TCON;
+
+ tmp = __raw_readl(addr);
+ tmp &= ~(MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START);
+ s5pv310_mct_write(tmp, addr);
+}
+
+static void s5pv310_mct_tick_start(enum mct_tick_type type,
+ unsigned long cycles)
+{
+ unsigned long tmp;
+ unsigned int tmp1, tmp2;
+ void __iomem *addr;
+
+ s5pv310_mct_tick_stop(type);
+
+ tmp1 = (1 << 31) | cycles; /* MCT_L_UPDATE_ICNTB */
+ tmp2 = 1 << 0; /* L_INT_ENB_CNTIE */
+
+ if (type == MCT_TICK0) {
+ s5pv310_mct_write(tmp1, S5PV310_MCT_L0_ICNTB);
+ s5pv310_mct_write(tmp2, S5PV310_MCT_L0_INT_ENB);
+
+ addr = S5PV310_MCT_L0_TCON;
+ } else {
+ s5pv310_mct_write(tmp1, S5PV310_MCT_L1_ICNTB);
+ s5pv310_mct_write(tmp2, S5PV310_MCT_L1_INT_ENB);
+
+ addr = S5PV310_MCT_L1_TCON;
+ }
+
+ tmp = __raw_readl(addr);
+ tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
+ MCT_L_TCON_INTERVAL_MODE;
+ s5pv310_mct_write(tmp, addr);
+}
+
+static inline int s5pv310_tick_set_next_event(enum mct_tick_type type,
+ unsigned long cycles)
+{
+ s5pv310_mct_tick_start(type, cycles);
+
+ return 0;
+}
+
+static inline void s5pv310_tick_set_mode(enum mct_tick_type type,
+ enum clock_event_mode mode)
+{
+ s5pv310_mct_tick_stop(type);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ s5pv310_mct_tick_start(type, clk_cnt_per_tick);
+ break;
+
+ case CLOCK_EVT_MODE_ONESHOT:
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
+}
+
+static int s5pv310_tick0_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ return s5pv310_tick_set_next_event(MCT_TICK0, cycles);
+}
+
+static int s5pv310_tick1_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ return s5pv310_tick_set_next_event(MCT_TICK1, cycles);
+}
+
+static void s5pv310_tick0_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ s5pv310_tick_set_mode(MCT_TICK0, mode);
+}
+
+static void s5pv310_tick1_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ s5pv310_tick_set_mode(MCT_TICK1, mode);
+}
+
+static struct clock_event_device mct_tick0_device = {
+ .name = "mct-tick0",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 450,
+ .shift = 20,
+ .set_next_event = s5pv310_tick0_set_next_event,
+ .set_mode = s5pv310_tick0_set_mode,
+};
+
+static struct clock_event_device mct_tick1_device = {
+ .name = "mct-tick1",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 450,
+ .shift = 20,
+ .set_next_event = s5pv310_tick1_set_next_event,
+ .set_mode = s5pv310_tick1_set_mode,
+};
+
+irqreturn_t s5pv310_mct0_event_isr(int irq, void *dev_id)
+{
+ struct clock_event_device *evt;
+
+ /* Clear the MCT tick interrupt */
+
+ evt = &mct_tick0_device;
+ if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
+ s5pv310_mct_tick_stop(MCT_TICK0);
+
+ s5pv310_mct_write(0x1, S5PV310_MCT_L0_INT_CSTAT);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+irqreturn_t s5pv310_mct1_event_isr(int irq, void *dev_id)
+{
+ struct clock_event_device *evt;
+
+ /* Clear the MCT tick interrupt */
+
+ evt = &mct_tick1_device;
+
+ if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
+ s5pv310_mct_tick_stop(MCT_TICK1);
+
+ s5pv310_mct_write(0x1, S5PV310_MCT_L1_INT_CSTAT);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction mct_tick0_event_irq = {
+ .name = "mct_tick0_irq",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
+ .handler = s5pv310_mct0_event_isr,
+};
+
+static struct irqaction mct_tick1_event_irq = {
+ .name = "mct_tick1_irq",
+ .flags = IRQF_TIMER | IRQF_NOBALANCING,
+ .handler = s5pv310_mct1_event_isr,
+};
+
+static void s5pv310_mct_clockevent_init(struct clock_event_device *dev)
+{
+ dev->mult = div_sc(clk_rate / 2, NSEC_PER_SEC, dev->shift);
+
+ dev->max_delta_ns = clockevent_delta2ns(0xfffffff, dev);
+ dev->min_delta_ns = clockevent_delta2ns(0xf, dev);
+}
+
+static void __init s5pv310_clockevent0_init(void)
+{
+ clk_cnt_per_tick = clk_rate / 2 / HZ;
+
+ s5pv310_mct_write(0x1, S5PV310_MCT_L0_TCNTB);
+ s5pv310_mct_clockevent_init(&mct_tick0_device);
+ mct_tick0_device.cpumask = cpumask_of(0);
+ clockevents_register_device(&mct_tick0_device);
+
+ setup_irq(IRQ_MCT_L0, &mct_tick0_event_irq);
+}
+
+static void __init s5pv310_clockevent1_init(void *info)
+{
+ s5pv310_mct_write(0x1, S5PV310_MCT_L1_TCNTB);
+ s5pv310_mct_clockevent_init(&mct_tick1_device);
+ mct_tick1_device.cpumask = cpumask_of(1);
+ clockevents_register_device(&mct_tick1_device);
+
+ irq_set_affinity(IRQ_MCT1, cpumask_of(1));
+ setup_irq(IRQ_MCT_L1, &mct_tick1_event_irq);
+}
+
+static void s5pv310_mct_frc_start(unsigned int hi, unsigned int lo)
+{
+ unsigned int tmp;
+
+ s5pv310_mct_write(lo, S5PV310_MCT_G_CNT_L);
+ s5pv310_mct_write(hi, S5PV310_MCT_G_CNT_U);
+
+ tmp = __raw_readl(S5PV310_MCT_G_TCON);
+ tmp |= (1 << 8); /* G_TCON_START */
+ s5pv310_mct_write(tmp, S5PV310_MCT_G_TCON);
+}
+
+/* Clocksource handling */
+
+static cycle_t s5pv310_frc_read(struct clocksource *cs)
+{
+ unsigned int lo, hi0, hi1;
+
+ hi0 = __raw_readl(S5PV310_MCT_G_CNT_U);
+ lo = __raw_readl(S5PV310_MCT_G_CNT_L);
+ dsb();
+ hi1 = __raw_readl(S5PV310_MCT_G_CNT_U);
+
+ if (hi0 != hi1) {
+ lo = __raw_readl(S5PV310_MCT_G_CNT_L);
+ hi1 = __raw_readl(S5PV310_MCT_G_CNT_U);
+ }
+
+ return ((cycle_t)hi1 << 32) | lo;
+}
+
+struct clocksource mct_frc = {
+ .name = "mct-frc",
+ .rating = 400,
+ .read = s5pv310_frc_read,
+ .mask = CLOCKSOURCE_MASK(64),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS ,
+};
+
+static void __init s5pv310_clocksource_init(void)
+{
+ s5pv310_mct_frc_start(0, 0);
+
+ if (clocksource_register_hz(&mct_frc, clk_rate))
+ panic("%s: can't register clocksource\n", mct_frc.name);
+}
+
+static void __init s5pv310_timer_resources(void)
+{
+ struct clk *mct_clk;
+
+ mct_clk = clk_get(NULL, "xtal");
+
+ clk_rate = clk_get_rate(mct_clk);
+}
+
+static void __init s5pv310_timer_init(void)
+{
+ s5pv310_timer_resources();
+
+ s5pv310_clockevent0_init();
+ s5pv310_clocksource_init();
+}
+
+static int __init secondary_clockevent_init(void)
+{
+ return smp_call_function_single(1, s5pv310_clockevent1_init, NULL, 0);
+}
+arch_initcall(secondary_clockevent_init);
+
+struct sys_timer s5pv310_timer = {
+ .init = s5pv310_timer_init,
+};
--
1.6.2.5
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