1 files changed, 555 insertions, 0 deletions

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
new file mode 100644
index 00000000000..b078d7cbc93
--- /dev/null
+++ b/drivers/clocksource/exynos_mct.c
@@ -0,0 +1,555 @@
+/* linux/arch/arm/mach-exynos4/mct.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * EXYNOS4 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 <linux/percpu.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/clocksource.h>
+
+#include <asm/localtimer.h>
+
+#include <plat/cpu.h>
+
+#include <mach/map.h>
+#include <mach/irqs.h>
+#include <asm/mach/time.h>
+
+#define EXYNOS4_MCTREG(x)		(x)
+#define EXYNOS4_MCT_G_CNT_L		EXYNOS4_MCTREG(0x100)
+#define EXYNOS4_MCT_G_CNT_U		EXYNOS4_MCTREG(0x104)
+#define EXYNOS4_MCT_G_CNT_WSTAT		EXYNOS4_MCTREG(0x110)
+#define EXYNOS4_MCT_G_COMP0_L		EXYNOS4_MCTREG(0x200)
+#define EXYNOS4_MCT_G_COMP0_U		EXYNOS4_MCTREG(0x204)
+#define EXYNOS4_MCT_G_COMP0_ADD_INCR	EXYNOS4_MCTREG(0x208)
+#define EXYNOS4_MCT_G_TCON		EXYNOS4_MCTREG(0x240)
+#define EXYNOS4_MCT_G_INT_CSTAT		EXYNOS4_MCTREG(0x244)
+#define EXYNOS4_MCT_G_INT_ENB		EXYNOS4_MCTREG(0x248)
+#define EXYNOS4_MCT_G_WSTAT		EXYNOS4_MCTREG(0x24C)
+#define _EXYNOS4_MCT_L_BASE		EXYNOS4_MCTREG(0x300)
+#define EXYNOS4_MCT_L_BASE(x)		(_EXYNOS4_MCT_L_BASE + (0x100 * x))
+#define EXYNOS4_MCT_L_MASK		(0xffffff00)
+
+#define MCT_L_TCNTB_OFFSET		(0x00)
+#define MCT_L_ICNTB_OFFSET		(0x08)
+#define MCT_L_TCON_OFFSET		(0x20)
+#define MCT_L_INT_CSTAT_OFFSET		(0x30)
+#define MCT_L_INT_ENB_OFFSET		(0x34)
+#define MCT_L_WSTAT_OFFSET		(0x40)
+#define MCT_G_TCON_START		(1 << 8)
+#define MCT_G_TCON_COMP0_AUTO_INC	(1 << 1)
+#define MCT_G_TCON_COMP0_ENABLE		(1 << 0)
+#define MCT_L_TCON_INTERVAL_MODE	(1 << 2)
+#define MCT_L_TCON_INT_START		(1 << 1)
+#define MCT_L_TCON_TIMER_START		(1 << 0)
+
+#define TICK_BASE_CNT	1
+
+enum {
+	MCT_INT_SPI,
+	MCT_INT_PPI
+};
+
+enum {
+	MCT_G0_IRQ,
+	MCT_G1_IRQ,
+	MCT_G2_IRQ,
+	MCT_G3_IRQ,
+	MCT_L0_IRQ,
+	MCT_L1_IRQ,
+	MCT_L2_IRQ,
+	MCT_L3_IRQ,
+	MCT_NR_IRQS,
+};
+
+static void __iomem *reg_base;
+static unsigned long clk_rate;
+static unsigned int mct_int_type;
+static int mct_irqs[MCT_NR_IRQS];
+
+struct mct_clock_event_device {
+	struct clock_event_device *evt;
+	unsigned long base;
+	char name[10];
+};
+
+static void exynos4_mct_write(unsigned int value, unsigned long offset)
+{
+	unsigned long stat_addr;
+	u32 mask;
+	u32 i;
+
+	__raw_writel(value, reg_base + offset);
+
+	if (likely(offset >= EXYNOS4_MCT_L_BASE(0))) {
+		stat_addr = (offset & ~EXYNOS4_MCT_L_MASK) + MCT_L_WSTAT_OFFSET;
+		switch (offset & EXYNOS4_MCT_L_MASK) {
+		case MCT_L_TCON_OFFSET:
+			mask = 1 << 3;		/* L_TCON write status */
+			break;
+		case MCT_L_ICNTB_OFFSET:
+			mask = 1 << 1;		/* L_ICNTB write status */
+			break;
+		case MCT_L_TCNTB_OFFSET:
+			mask = 1 << 0;		/* L_TCNTB write status */
+			break;
+		default:
+			return;
+		}
+	} else {
+		switch (offset) {
+		case EXYNOS4_MCT_G_TCON:
+			stat_addr = EXYNOS4_MCT_G_WSTAT;
+			mask = 1 << 16;		/* G_TCON write status */
+			break;
+		case EXYNOS4_MCT_G_COMP0_L:
+			stat_addr = EXYNOS4_MCT_G_WSTAT;
+			mask = 1 << 0;		/* G_COMP0_L write status */
+			break;
+		case EXYNOS4_MCT_G_COMP0_U:
+			stat_addr = EXYNOS4_MCT_G_WSTAT;
+			mask = 1 << 1;		/* G_COMP0_U write status */
+			break;
+		case EXYNOS4_MCT_G_COMP0_ADD_INCR:
+			stat_addr = EXYNOS4_MCT_G_WSTAT;
+			mask = 1 << 2;		/* G_COMP0_ADD_INCR w status */
+			break;
+		case EXYNOS4_MCT_G_CNT_L:
+			stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
+			mask = 1 << 0;		/* G_CNT_L write status */
+			break;
+		case EXYNOS4_MCT_G_CNT_U:
+			stat_addr = EXYNOS4_MCT_G_CNT_WSTAT;
+			mask = 1 << 1;		/* G_CNT_U write status */
+			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(reg_base + stat_addr) & mask) {
+			__raw_writel(mask, reg_base + stat_addr);
+			return;
+		}
+
+	panic("MCT hangs after writing %d (offset:0x%lx)\n", value, offset);
+}
+
+/* Clocksource handling */
+static void exynos4_mct_frc_start(u32 hi, u32 lo)
+{
+	u32 reg;
+
+	exynos4_mct_write(lo, EXYNOS4_MCT_G_CNT_L);
+	exynos4_mct_write(hi, EXYNOS4_MCT_G_CNT_U);
+
+	reg = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
+	reg |= MCT_G_TCON_START;
+	exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON);
+}
+
+static cycle_t exynos4_frc_read(struct clocksource *cs)
+{
+	unsigned int lo, hi;
+	u32 hi2 = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_U);
+
+	do {
+		hi = hi2;
+		lo = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_L);
+		hi2 = __raw_readl(reg_base + EXYNOS4_MCT_G_CNT_U);
+	} while (hi != hi2);
+
+	return ((cycle_t)hi << 32) | lo;
+}
+
+static void exynos4_frc_resume(struct clocksource *cs)
+{
+	exynos4_mct_frc_start(0, 0);
+}
+
+struct clocksource mct_frc = {
+	.name		= "mct-frc",
+	.rating		= 400,
+	.read		= exynos4_frc_read,
+	.mask		= CLOCKSOURCE_MASK(64),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.resume		= exynos4_frc_resume,
+};
+
+static void __init exynos4_clocksource_init(void)
+{
+	exynos4_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 exynos4_mct_comp0_stop(void)
+{
+	unsigned int tcon;
+
+	tcon = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
+	tcon &= ~(MCT_G_TCON_COMP0_ENABLE | MCT_G_TCON_COMP0_AUTO_INC);
+
+	exynos4_mct_write(tcon, EXYNOS4_MCT_G_TCON);
+	exynos4_mct_write(0, EXYNOS4_MCT_G_INT_ENB);
+}
+
+static void exynos4_mct_comp0_start(enum clock_event_mode mode,
+				    unsigned long cycles)
+{
+	unsigned int tcon;
+	cycle_t comp_cycle;
+
+	tcon = __raw_readl(reg_base + EXYNOS4_MCT_G_TCON);
+
+	if (mode == CLOCK_EVT_MODE_PERIODIC) {
+		tcon |= MCT_G_TCON_COMP0_AUTO_INC;
+		exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
+	}
+
+	comp_cycle = exynos4_frc_read(&mct_frc) + cycles;
+	exynos4_mct_write((u32)comp_cycle, EXYNOS4_MCT_G_COMP0_L);
+	exynos4_mct_write((u32)(comp_cycle >> 32), EXYNOS4_MCT_G_COMP0_U);
+
+	exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_ENB);
+
+	tcon |= MCT_G_TCON_COMP0_ENABLE;
+	exynos4_mct_write(tcon , EXYNOS4_MCT_G_TCON);
+}
+
+static int exynos4_comp_set_next_event(unsigned long cycles,
+				       struct clock_event_device *evt)
+{
+	exynos4_mct_comp0_start(evt->mode, cycles);
+
+	return 0;
+}
+
+static void exynos4_comp_set_mode(enum clock_event_mode mode,
+				  struct clock_event_device *evt)
+{
+	unsigned long cycles_per_jiffy;
+	exynos4_mct_comp0_stop();
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		cycles_per_jiffy =
+			(((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
+		exynos4_mct_comp0_start(mode, cycles_per_jiffy);
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_RESUME:
+		break;
+	}
+}
+
+static struct clock_event_device mct_comp_device = {
+	.name		= "mct-comp",
+	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.rating		= 250,
+	.set_next_event	= exynos4_comp_set_next_event,
+	.set_mode	= exynos4_comp_set_mode,
+};
+
+static irqreturn_t exynos4_mct_comp_isr(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+
+	exynos4_mct_write(0x1, EXYNOS4_MCT_G_INT_CSTAT);
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction mct_comp_event_irq = {
+	.name		= "mct_comp_irq",
+	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= exynos4_mct_comp_isr,
+	.dev_id		= &mct_comp_device,
+};
+
+static void exynos4_clockevent_init(void)
+{
+	mct_comp_device.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&mct_comp_device, clk_rate,
+					0xf, 0xffffffff);
+	setup_irq(mct_irqs[MCT_G0_IRQ], &mct_comp_event_irq);
+}
+
+#ifdef CONFIG_LOCAL_TIMERS
+
+static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
+
+/* Clock event handling */
+static void exynos4_mct_tick_stop(struct mct_clock_event_device *mevt)
+{
+	unsigned long tmp;
+	unsigned long mask = MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START;
+	unsigned long offset = mevt->base + MCT_L_TCON_OFFSET;
+
+	tmp = __raw_readl(reg_base + offset);
+	if (tmp & mask) {
+		tmp &= ~mask;
+		exynos4_mct_write(tmp, offset);
+	}
+}
+
+static void exynos4_mct_tick_start(unsigned long cycles,
+				   struct mct_clock_event_device *mevt)
+{
+	unsigned long tmp;
+
+	exynos4_mct_tick_stop(mevt);
+
+	tmp = (1 << 31) | cycles;	/* MCT_L_UPDATE_ICNTB */
+
+	/* update interrupt count buffer */
+	exynos4_mct_write(tmp, mevt->base + MCT_L_ICNTB_OFFSET);
+
+	/* enable MCT tick interrupt */
+	exynos4_mct_write(0x1, mevt->base + MCT_L_INT_ENB_OFFSET);
+
+	tmp = __raw_readl(reg_base + mevt->base + MCT_L_TCON_OFFSET);
+	tmp |= MCT_L_TCON_INT_START | MCT_L_TCON_TIMER_START |
+	       MCT_L_TCON_INTERVAL_MODE;
+	exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
+}
+
+static int exynos4_tick_set_next_event(unsigned long cycles,
+				       struct clock_event_device *evt)
+{
+	struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
+
+	exynos4_mct_tick_start(cycles, mevt);
+
+	return 0;
+}
+
+static inline void exynos4_tick_set_mode(enum clock_event_mode mode,
+					 struct clock_event_device *evt)
+{
+	struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
+	unsigned long cycles_per_jiffy;
+
+	exynos4_mct_tick_stop(mevt);
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		cycles_per_jiffy =
+			(((unsigned long long) NSEC_PER_SEC / HZ * evt->mult) >> evt->shift);
+		exynos4_mct_tick_start(cycles_per_jiffy, mevt);
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_RESUME:
+		break;
+	}
+}
+
+static int exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
+{
+	struct clock_event_device *evt = mevt->evt;
+
+	/*
+	 * This is for supporting oneshot mode.
+	 * Mct would generate interrupt periodically
+	 * without explicit stopping.
+	 */
+	if (evt->mode != CLOCK_EVT_MODE_PERIODIC)
+		exynos4_mct_tick_stop(mevt);
+
+	/* Clear the MCT tick interrupt */
+	if (__raw_readl(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1) {
+		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
+{
+	struct mct_clock_event_device *mevt = dev_id;
+	struct clock_event_device *evt = mevt->evt;
+
+	exynos4_mct_tick_clear(mevt);
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction mct_tick0_event_irq = {
+	.name		= "mct_tick0_irq",
+	.flags		= IRQF_TIMER | IRQF_NOBALANCING,
+	.handler	= exynos4_mct_tick_isr,
+};
+
+static struct irqaction mct_tick1_event_irq = {
+	.name		= "mct_tick1_irq",
+	.flags		= IRQF_TIMER | IRQF_NOBALANCING,
+	.handler	= exynos4_mct_tick_isr,
+};
+
+static int __cpuinit exynos4_local_timer_setup(struct clock_event_device *evt)
+{
+	struct mct_clock_event_device *mevt;
+	unsigned int cpu = smp_processor_id();
+
+	mevt = this_cpu_ptr(&percpu_mct_tick);
+	mevt->evt = evt;
+
+	mevt->base = EXYNOS4_MCT_L_BASE(cpu);
+	sprintf(mevt->name, "mct_tick%d", cpu);
+
+	evt->name = mevt->name;
+	evt->cpumask = cpumask_of(cpu);
+	evt->set_next_event = exynos4_tick_set_next_event;
+	evt->set_mode = exynos4_tick_set_mode;
+	evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+	evt->rating = 450;
+	clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
+					0xf, 0x7fffffff);
+
+	exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
+
+	if (mct_int_type == MCT_INT_SPI) {
+		if (cpu == 0) {
+			mct_tick0_event_irq.dev_id = mevt;
+			evt->irq = mct_irqs[MCT_L0_IRQ];
+			setup_irq(evt->irq, &mct_tick0_event_irq);
+		} else {
+			mct_tick1_event_irq.dev_id = mevt;
+			evt->irq = mct_irqs[MCT_L1_IRQ];
+			setup_irq(evt->irq, &mct_tick1_event_irq);
+			irq_set_affinity(evt->irq, cpumask_of(1));
+		}
+	} else {
+		enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
+	}
+
+	return 0;
+}
+
+static void exynos4_local_timer_stop(struct clock_event_device *evt)
+{
+	unsigned int cpu = smp_processor_id();
+	evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
+	if (mct_int_type == MCT_INT_SPI)
+		if (cpu == 0)
+			remove_irq(evt->irq, &mct_tick0_event_irq);
+		else
+			remove_irq(evt->irq, &mct_tick1_event_irq);
+	else
+		disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
+}
+
+static struct local_timer_ops exynos4_mct_tick_ops __cpuinitdata = {
+	.setup	= exynos4_local_timer_setup,
+	.stop	= exynos4_local_timer_stop,
+};
+#endif /* CONFIG_LOCAL_TIMERS */
+
+static void __init exynos4_timer_resources(void __iomem *base)
+{
+	struct clk *mct_clk;
+	mct_clk = clk_get(NULL, "xtal");
+
+	clk_rate = clk_get_rate(mct_clk);
+
+	reg_base = base;
+	if (!reg_base)
+		panic("%s: unable to ioremap mct address space\n", __func__);
+
+#ifdef CONFIG_LOCAL_TIMERS
+	if (mct_int_type == MCT_INT_PPI) {
+		int err;
+
+		err = request_percpu_irq(mct_irqs[MCT_L0_IRQ],
+					 exynos4_mct_tick_isr, "MCT",
+					 &percpu_mct_tick);
+		WARN(err, "MCT: can't request IRQ %d (%d)\n",
+		     mct_irqs[MCT_L0_IRQ], err);
+	}
+
+	local_timer_register(&exynos4_mct_tick_ops);
+#endif /* CONFIG_LOCAL_TIMERS */
+}
+
+void __init mct_init(void)
+{
+	if (soc_is_exynos4210()) {
+		mct_irqs[MCT_G0_IRQ] = EXYNOS4_IRQ_MCT_G0;
+		mct_irqs[MCT_L0_IRQ] = EXYNOS4_IRQ_MCT_L0;
+		mct_irqs[MCT_L1_IRQ] = EXYNOS4_IRQ_MCT_L1;
+		mct_int_type = MCT_INT_SPI;
+	} else {
+		panic("unable to determine mct controller type\n");
+	}
+
+	exynos4_timer_resources(S5P_VA_SYSTIMER);
+	exynos4_clocksource_init();
+	exynos4_clockevent_init();
+}
+
+static void __init mct_init_dt(struct device_node *np, unsigned int int_type)
+{
+	u32 nr_irqs, i;
+
+	mct_int_type = int_type;
+
+	/* This driver uses only one global timer interrupt */
+	mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
+
+	/*
+	 * Find out the number of local irqs specified. The local
+	 * timer irqs are specified after the four global timer
+	 * irqs are specified.
+	 */
+	nr_irqs = of_irq_count(np);
+	for (i = MCT_L0_IRQ; i < nr_irqs; i++)
+		mct_irqs[i] = irq_of_parse_and_map(np, i);
+
+	exynos4_timer_resources(of_iomap(np, 0));
+	exynos4_clocksource_init();
+	exynos4_clockevent_init();
+}
+
+
+static void __init mct_init_spi(struct device_node *np)
+{
+	return mct_init_dt(np, MCT_INT_SPI);
+}
+
+static void __init mct_init_ppi(struct device_node *np)
+{
+	return mct_init_dt(np, MCT_INT_PPI);
+}
+CLOCKSOURCE_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
+CLOCKSOURCE_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);