ARM: S5P: HRT support

This patch adds support HR-Timer(High Resolution Timer) and dynamic
tick system for S5P SoCs. There are many clock sources for HR-Timer
on S5P SoCs. The PWM timer, RTC, System Timer, and MCT can be used
for clock source.
This patch can only support PWM timer for clock source of S5P64X0
and S5PV210.

Signed-off-by: Sangbeom Kim <sbkim73@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/plat-s5p/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_S5P_GPIO_INT)	+= irq-gpioint.o
 obj-$(CONFIG_S5P_SYSTEM_MMU)	+= sysmmu.o
 obj-$(CONFIG_PM)		+= pm.o
 obj-$(CONFIG_PM)		+= irq-pm.o
+obj-$(CONFIG_S5P_HRT) 		+= s5p-time.o
 
 # devices
 

arch/arm/plat-s5p/include/plat/s5p-time.h

@@ -0,0 +1,40 @@
+/* linux/arch/arm/plat-s5p/include/plat/s5p-time.h
+ *
+ * Copyright 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * Header file for s5p time 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.
+*/
+
+#ifndef __ASM_PLAT_S5P_TIME_H
+#define __ASM_PLAT_S5P_TIME_H __FILE__
+
+/* S5P HR-Timer Clock mode */
+enum s5p_timer_mode {
+	S5P_PWM0,
+	S5P_PWM1,
+	S5P_PWM2,
+	S5P_PWM3,
+	S5P_PWM4,
+};
+
+struct s5p_timer_source {
+	unsigned int event_id;
+	unsigned int source_id;
+};
+
+/* Be able to sleep for atleast 4 seconds (usually more) */
+#define S5PTIMER_MIN_RANGE	4
+
+#define TCNT_MAX		0xffffffff
+#define NON_PERIODIC		0
+#define PERIODIC		1
+
+extern void __init s5p_set_timer_source(enum s5p_timer_mode event,
+					enum s5p_timer_mode source);
+extern	struct sys_timer s5p_timer;
+#endif /* __ASM_PLAT_S5P_TIME_H */

arch/arm/plat-s5p/s5p-time.c

@@ -0,0 +1,448 @@
+/* linux/arch/arm/plat-s5p/s5p-time.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * S5P - Common hr-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 <asm/smp_twd.h>
+#include <asm/mach/time.h>
+#include <asm/mach/arch.h>
+#include <asm/mach/map.h>
+#include <asm/sched_clock.h>
+
+#include <mach/map.h>
+#include <plat/devs.h>
+#include <plat/regs-timer.h>
+#include <plat/s5p-time.h>
+
+static struct clk *tin_event;
+static struct clk *tin_source;
+static struct clk *tdiv_event;
+static struct clk *tdiv_source;
+static struct clk *timerclk;
+static struct s5p_timer_source timer_source;
+static unsigned long clock_count_per_tick;
+static void s5p_timer_resume(void);
+
+static void s5p_time_stop(enum s5p_timer_mode mode)
+{
+	unsigned long tcon;
+
+	tcon = __raw_readl(S3C2410_TCON);
+
+	switch (mode) {
+	case S5P_PWM0:
+		tcon &= ~S3C2410_TCON_T0START;
+		break;
+
+	case S5P_PWM1:
+		tcon &= ~S3C2410_TCON_T1START;
+		break;
+
+	case S5P_PWM2:
+		tcon &= ~S3C2410_TCON_T2START;
+		break;
+
+	case S5P_PWM3:
+		tcon &= ~S3C2410_TCON_T3START;
+		break;
+
+	case S5P_PWM4:
+		tcon &= ~S3C2410_TCON_T4START;
+		break;
+
+	default:
+		printk(KERN_ERR "Invalid Timer %d\n", mode);
+		break;
+	}
+	__raw_writel(tcon, S3C2410_TCON);
+}
+
+static void s5p_time_setup(enum s5p_timer_mode mode, unsigned long tcnt)
+{
+	unsigned long tcon;
+
+	tcon = __raw_readl(S3C2410_TCON);
+
+	tcnt--;
+
+	switch (mode) {
+	case S5P_PWM0:
+		tcon &= ~(0x0f << 0);
+		tcon |= S3C2410_TCON_T0MANUALUPD;
+		break;
+
+	case S5P_PWM1:
+		tcon &= ~(0x0f << 8);
+		tcon |= S3C2410_TCON_T1MANUALUPD;
+		break;
+
+	case S5P_PWM2:
+		tcon &= ~(0x0f << 12);
+		tcon |= S3C2410_TCON_T2MANUALUPD;
+		break;
+
+	case S5P_PWM3:
+		tcon &= ~(0x0f << 16);
+		tcon |= S3C2410_TCON_T3MANUALUPD;
+		break;
+
+	case S5P_PWM4:
+		tcon &= ~(0x07 << 20);
+		tcon |= S3C2410_TCON_T4MANUALUPD;
+		break;
+
+	default:
+		printk(KERN_ERR "Invalid Timer %d\n", mode);
+		break;
+	}
+
+	__raw_writel(tcnt, S3C2410_TCNTB(mode));
+	__raw_writel(tcnt, S3C2410_TCMPB(mode));
+	__raw_writel(tcon, S3C2410_TCON);
+}
+
+static void s5p_time_start(enum s5p_timer_mode mode, bool periodic)
+{
+	unsigned long tcon;
+
+	tcon  = __raw_readl(S3C2410_TCON);
+
+	switch (mode) {
+	case S5P_PWM0:
+		tcon |= S3C2410_TCON_T0START;
+		tcon &= ~S3C2410_TCON_T0MANUALUPD;
+
+		if (periodic)
+			tcon |= S3C2410_TCON_T0RELOAD;
+		else
+			tcon &= ~S3C2410_TCON_T0RELOAD;
+		break;
+
+	case S5P_PWM1:
+		tcon |= S3C2410_TCON_T1START;
+		tcon &= ~S3C2410_TCON_T1MANUALUPD;
+
+		if (periodic)
+			tcon |= S3C2410_TCON_T1RELOAD;
+		else
+			tcon &= ~S3C2410_TCON_T1RELOAD;
+		break;
+
+	case S5P_PWM2:
+		tcon |= S3C2410_TCON_T2START;
+		tcon &= ~S3C2410_TCON_T2MANUALUPD;
+
+		if (periodic)
+			tcon |= S3C2410_TCON_T2RELOAD;
+		else
+			tcon &= ~S3C2410_TCON_T2RELOAD;
+		break;
+
+	case S5P_PWM3:
+		tcon |= S3C2410_TCON_T3START;
+		tcon &= ~S3C2410_TCON_T3MANUALUPD;
+
+		if (periodic)
+			tcon |= S3C2410_TCON_T3RELOAD;
+		else
+			tcon &= ~S3C2410_TCON_T3RELOAD;
+		break;
+
+	case S5P_PWM4:
+		tcon |= S3C2410_TCON_T4START;
+		tcon &= ~S3C2410_TCON_T4MANUALUPD;
+
+		if (periodic)
+			tcon |= S3C2410_TCON_T4RELOAD;
+		else
+			tcon &= ~S3C2410_TCON_T4RELOAD;
+		break;
+
+	default:
+		printk(KERN_ERR "Invalid Timer %d\n", mode);
+		break;
+	}
+	__raw_writel(tcon, S3C2410_TCON);
+}
+
+static int s5p_set_next_event(unsigned long cycles,
+				struct clock_event_device *evt)
+{
+	s5p_time_setup(timer_source.event_id, cycles);
+	s5p_time_start(timer_source.event_id, NON_PERIODIC);
+
+	return 0;
+}
+
+static void s5p_set_mode(enum clock_event_mode mode,
+				struct clock_event_device *evt)
+{
+	s5p_time_stop(timer_source.event_id);
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		s5p_time_setup(timer_source.event_id, clock_count_per_tick);
+		s5p_time_start(timer_source.event_id, PERIODIC);
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+		break;
+
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		break;
+
+	case CLOCK_EVT_MODE_RESUME:
+		s5p_timer_resume();
+		break;
+	}
+}
+
+static void s5p_timer_resume(void)
+{
+	/* event timer restart */
+	s5p_time_setup(timer_source.event_id, clock_count_per_tick);
+	s5p_time_start(timer_source.event_id, PERIODIC);
+
+	/* source timer restart */
+	s5p_time_setup(timer_source.source_id, TCNT_MAX);
+	s5p_time_start(timer_source.source_id, PERIODIC);
+}
+
+void __init s5p_set_timer_source(enum s5p_timer_mode event,
+				 enum s5p_timer_mode source)
+{
+	s3c_device_timer[event].dev.bus = &platform_bus_type;
+	s3c_device_timer[source].dev.bus = &platform_bus_type;
+
+	timer_source.event_id = event;
+	timer_source.source_id = source;
+}
+
+static struct clock_event_device time_event_device = {
+	.name		= "s5p_event_timer",
+	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.rating		= 200,
+	.set_next_event	= s5p_set_next_event,
+	.set_mode	= s5p_set_mode,
+};
+
+static irqreturn_t s5p_clock_event_isr(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction s5p_clock_event_irq = {
+	.name		= "s5p_time_irq",
+	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= s5p_clock_event_isr,
+	.dev_id		= &time_event_device,
+};
+
+static void __init s5p_clockevent_init(void)
+{
+	unsigned long pclk;
+	unsigned long clock_rate;
+	unsigned int irq_number;
+	struct clk *tscaler;
+
+	pclk = clk_get_rate(timerclk);
+
+	tscaler = clk_get_parent(tdiv_event);
+
+	clk_set_rate(tscaler, pclk / 2);
+	clk_set_rate(tdiv_event, pclk / 2);
+	clk_set_parent(tin_event, tdiv_event);
+
+	clock_rate = clk_get_rate(tin_event);
+	clock_count_per_tick = clock_rate / HZ;
+
+	clockevents_calc_mult_shift(&time_event_device,
+				    clock_rate, S5PTIMER_MIN_RANGE);
+	time_event_device.max_delta_ns =
+		clockevent_delta2ns(-1, &time_event_device);
+	time_event_device.min_delta_ns =
+		clockevent_delta2ns(1, &time_event_device);
+
+	time_event_device.cpumask = cpumask_of(0);
+	clockevents_register_device(&time_event_device);
+
+	irq_number = timer_source.event_id + IRQ_TIMER0;
+	setup_irq(irq_number, &s5p_clock_event_irq);
+}
+
+static cycle_t s5p_timer_read(struct clocksource *cs)
+{
+	unsigned long offset = 0;
+
+	switch (timer_source.source_id) {
+	case S5P_PWM0:
+	case S5P_PWM1:
+	case S5P_PWM2:
+	case S5P_PWM3:
+		offset = (timer_source.source_id * 0x0c) + 0x14;
+		break;
+
+	case S5P_PWM4:
+		offset = 0x40;
+		break;
+
+	default:
+		printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
+		return 0;
+	}
+
+	return (cycle_t) ~__raw_readl(S3C_TIMERREG(offset));
+}
+
+/*
+ * Override the global weak sched_clock symbol with this
+ * local implementation which uses the clocksource to get some
+ * better resolution when scheduling the kernel. We accept that
+ * this wraps around for now, since it is just a relative time
+ * stamp. (Inspired by U300 implementation.)
+ */
+static DEFINE_CLOCK_DATA(cd);
+
+unsigned long long notrace sched_clock(void)
+{
+	u32 cyc;
+	unsigned long offset = 0;
+
+	switch (timer_source.source_id) {
+	case S5P_PWM0:
+	case S5P_PWM1:
+	case S5P_PWM2:
+	case S5P_PWM3:
+		offset = (timer_source.source_id * 0x0c) + 0x14;
+		break;
+
+	case S5P_PWM4:
+		offset = 0x40;
+		break;
+
+	default:
+		printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
+		return 0;
+	}
+
+	cyc = ~__raw_readl(S3C_TIMERREG(offset));
+	return cyc_to_sched_clock(&cd, cyc, (u32)~0);
+}
+
+static void notrace s5p_update_sched_clock(void)
+{
+	u32 cyc;
+	unsigned long offset = 0;
+
+	switch (timer_source.source_id) {
+	case S5P_PWM0:
+	case S5P_PWM1:
+	case S5P_PWM2:
+	case S5P_PWM3:
+		offset = (timer_source.source_id * 0x0c) + 0x14;
+		break;
+
+	case S5P_PWM4:
+		offset = 0x40;
+		break;
+
+	default:
+		printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
+	}
+
+	cyc = ~__raw_readl(S3C_TIMERREG(offset));
+	update_sched_clock(&cd, cyc, (u32)~0);
+}
+
+struct clocksource time_clocksource = {
+	.name		= "s5p_clocksource_timer",
+	.rating		= 250,
+	.read		= s5p_timer_read,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init s5p_clocksource_init(void)
+{
+	unsigned long pclk;
+	unsigned long clock_rate;
+
+	pclk = clk_get_rate(timerclk);
+
+	clk_set_rate(tdiv_source, pclk / 2);
+	clk_set_parent(tin_source, tdiv_source);
+
+	clock_rate = clk_get_rate(tin_source);
+
+	init_sched_clock(&cd, s5p_update_sched_clock, 32, clock_rate);
+
+	s5p_time_setup(timer_source.source_id, TCNT_MAX);
+	s5p_time_start(timer_source.source_id, PERIODIC);
+
+	if (clocksource_register_hz(&time_clocksource, clock_rate))
+		panic("%s: can't register clocksource\n", time_clocksource.name);
+}
+
+static void __init s5p_timer_resources(void)
+{
+
+	unsigned long event_id = timer_source.event_id;
+	unsigned long source_id = timer_source.source_id;
+
+	timerclk = clk_get(NULL, "timers");
+	if (IS_ERR(timerclk))
+		panic("failed to get timers clock for timer");
+
+	clk_enable(timerclk);
+
+	tin_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tin");
+	if (IS_ERR(tin_event))
+		panic("failed to get pwm-tin clock for event timer");
+
+	tdiv_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tdiv");
+	if (IS_ERR(tdiv_event))
+		panic("failed to get pwm-tdiv clock for event timer");
+
+	clk_enable(tin_event);
+
+	tin_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tin");
+	if (IS_ERR(tin_source))
+		panic("failed to get pwm-tin clock for source timer");
+
+	tdiv_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tdiv");
+	if (IS_ERR(tdiv_source))
+		panic("failed to get pwm-tdiv clock for source timer");
+
+	clk_enable(tin_source);
+}
+
+static void __init s5p_timer_init(void)
+{
+	s5p_timer_resources();
+	s5p_clockevent_init();
+	s5p_clocksource_init();
+}
+
+struct sys_timer s5p_timer = {
+	.init		= s5p_timer_init,
+};