tmp_suning_uos_patched/drivers/clocksource/exynos_mct.c
Marek Szyprowski 6282edb72b clocksource/drivers/exynos_mct: Increase priority over ARM arch timer
Exynos SoCs based on CA7/CA15 have 2 timer interfaces: custom Exynos MCT
(Multi Core Timer) and standard ARM Architected Timers.

There are use cases, where both timer interfaces are used simultanously.
One of such examples is using Exynos MCT for the main system timer and
ARM Architected Timers for the KVM and virtualized guests (KVM requires
arch timers).

Exynos Multi-Core Timer driver (exynos_mct) must be however started
before ARM Architected Timers (arch_timer), because they both share some
common hardware blocks (global system counter) and turning on MCT is
needed to get ARM Architected Timer working properly.

To ensure selecting Exynos MCT as the main system timer, increase MCT
timer rating. To ensure proper starting order of both timers during
suspend/resume cycle, increase MCT hotplug priority over ARM Archictected
Timers.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2019-06-25 19:49:18 +02:00

621 lines
16 KiB
C

/* 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/interrupt.h>
#include <linux/irq.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/cpu.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 <linux/sched_clock.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_L4_IRQ,
MCT_L5_IRQ,
MCT_L6_IRQ,
MCT_L7_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;
writel_relaxed(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 (readl_relaxed(reg_base + stat_addr) & mask) {
writel_relaxed(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(void)
{
u32 reg;
reg = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
reg |= MCT_G_TCON_START;
exynos4_mct_write(reg, EXYNOS4_MCT_G_TCON);
}
/**
* exynos4_read_count_64 - Read all 64-bits of the global counter
*
* This will read all 64-bits of the global counter taking care to make sure
* that the upper and lower half match. Note that reading the MCT can be quite
* slow (hundreds of nanoseconds) so you should use the 32-bit (lower half
* only) version when possible.
*
* Returns the number of cycles in the global counter.
*/
static u64 exynos4_read_count_64(void)
{
unsigned int lo, hi;
u32 hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
do {
hi = hi2;
lo = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
hi2 = readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_U);
} while (hi != hi2);
return ((u64)hi << 32) | lo;
}
/**
* exynos4_read_count_32 - Read the lower 32-bits of the global counter
*
* This will read just the lower 32-bits of the global counter. This is marked
* as notrace so it can be used by the scheduler clock.
*
* Returns the number of cycles in the global counter (lower 32 bits).
*/
static u32 notrace exynos4_read_count_32(void)
{
return readl_relaxed(reg_base + EXYNOS4_MCT_G_CNT_L);
}
static u64 exynos4_frc_read(struct clocksource *cs)
{
return exynos4_read_count_32();
}
static void exynos4_frc_resume(struct clocksource *cs)
{
exynos4_mct_frc_start();
}
static struct clocksource mct_frc = {
.name = "mct-frc",
.rating = 450, /* use value higher than ARM arch timer */
.read = exynos4_frc_read,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.resume = exynos4_frc_resume,
};
static u64 notrace exynos4_read_sched_clock(void)
{
return exynos4_read_count_32();
}
#if defined(CONFIG_ARM)
static struct delay_timer exynos4_delay_timer;
static cycles_t exynos4_read_current_timer(void)
{
BUILD_BUG_ON_MSG(sizeof(cycles_t) != sizeof(u32),
"cycles_t needs to move to 32-bit for ARM64 usage");
return exynos4_read_count_32();
}
#endif
static int __init exynos4_clocksource_init(void)
{
exynos4_mct_frc_start();
#if defined(CONFIG_ARM)
exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer;
exynos4_delay_timer.freq = clk_rate;
register_current_timer_delay(&exynos4_delay_timer);
#endif
if (clocksource_register_hz(&mct_frc, clk_rate))
panic("%s: can't register clocksource\n", mct_frc.name);
sched_clock_register(exynos4_read_sched_clock, 32, clk_rate);
return 0;
}
static void exynos4_mct_comp0_stop(void)
{
unsigned int tcon;
tcon = readl_relaxed(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(bool periodic, unsigned long cycles)
{
unsigned int tcon;
u64 comp_cycle;
tcon = readl_relaxed(reg_base + EXYNOS4_MCT_G_TCON);
if (periodic) {
tcon |= MCT_G_TCON_COMP0_AUTO_INC;
exynos4_mct_write(cycles, EXYNOS4_MCT_G_COMP0_ADD_INCR);
}
comp_cycle = exynos4_read_count_64() + 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(false, cycles);
return 0;
}
static int mct_set_state_shutdown(struct clock_event_device *evt)
{
exynos4_mct_comp0_stop();
return 0;
}
static int mct_set_state_periodic(struct clock_event_device *evt)
{
unsigned long cycles_per_jiffy;
cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
>> evt->shift);
exynos4_mct_comp0_stop();
exynos4_mct_comp0_start(true, cycles_per_jiffy);
return 0;
}
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_state_periodic = mct_set_state_periodic,
.set_state_shutdown = mct_set_state_shutdown,
.set_state_oneshot = mct_set_state_shutdown,
.set_state_oneshot_stopped = mct_set_state_shutdown,
.tick_resume = mct_set_state_shutdown,
};
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 int 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);
return 0;
}
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 = readl_relaxed(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 = readl_relaxed(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 void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
{
/* Clear the MCT tick interrupt */
if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
}
static int exynos4_tick_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
struct mct_clock_event_device *mevt;
mevt = container_of(evt, struct mct_clock_event_device, evt);
exynos4_mct_tick_start(cycles, mevt);
return 0;
}
static int set_state_shutdown(struct clock_event_device *evt)
{
struct mct_clock_event_device *mevt;
mevt = container_of(evt, struct mct_clock_event_device, evt);
exynos4_mct_tick_stop(mevt);
exynos4_mct_tick_clear(mevt);
return 0;
}
static int set_state_periodic(struct clock_event_device *evt)
{
struct mct_clock_event_device *mevt;
unsigned long cycles_per_jiffy;
mevt = container_of(evt, struct mct_clock_event_device, evt);
cycles_per_jiffy = (((unsigned long long)NSEC_PER_SEC / HZ * evt->mult)
>> evt->shift);
exynos4_mct_tick_stop(mevt);
exynos4_mct_tick_start(cycles_per_jiffy, mevt);
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;
/*
* This is for supporting oneshot mode.
* Mct would generate interrupt periodically
* without explicit stopping.
*/
if (!clockevent_state_periodic(&mevt->evt))
exynos4_mct_tick_stop(mevt);
exynos4_mct_tick_clear(mevt);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static int exynos4_mct_starting_cpu(unsigned int cpu)
{
struct mct_clock_event_device *mevt =
per_cpu_ptr(&percpu_mct_tick, cpu);
struct clock_event_device *evt = &mevt->evt;
mevt->base = EXYNOS4_MCT_L_BASE(cpu);
snprintf(mevt->name, sizeof(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_state_periodic = set_state_periodic;
evt->set_state_shutdown = set_state_shutdown;
evt->set_state_oneshot = set_state_shutdown;
evt->set_state_oneshot_stopped = set_state_shutdown;
evt->tick_resume = set_state_shutdown;
evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
evt->rating = 500; /* use value higher than ARM arch timer */
exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
if (mct_int_type == MCT_INT_SPI) {
if (evt->irq == -1)
return -EIO;
irq_force_affinity(evt->irq, cpumask_of(cpu));
enable_irq(evt->irq);
} else {
enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
}
clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
0xf, 0x7fffffff);
return 0;
}
static int exynos4_mct_dying_cpu(unsigned int cpu)
{
struct mct_clock_event_device *mevt =
per_cpu_ptr(&percpu_mct_tick, cpu);
struct clock_event_device *evt = &mevt->evt;
evt->set_state_shutdown(evt);
if (mct_int_type == MCT_INT_SPI) {
if (evt->irq != -1)
disable_irq_nosync(evt->irq);
exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
} else {
disable_percpu_irq(mct_irqs[MCT_L0_IRQ]);
}
return 0;
}
static int __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
{
int err, cpu;
struct clk *mct_clk, *tick_clk;
tick_clk = of_clk_get_by_name(np, "fin_pll");
if (IS_ERR(tick_clk))
panic("%s: unable to determine tick clock rate\n", __func__);
clk_rate = clk_get_rate(tick_clk);
mct_clk = of_clk_get_by_name(np, "mct");
if (IS_ERR(mct_clk))
panic("%s: unable to retrieve mct clock instance\n", __func__);
clk_prepare_enable(mct_clk);
reg_base = base;
if (!reg_base)
panic("%s: unable to ioremap mct address space\n", __func__);
if (mct_int_type == MCT_INT_PPI) {
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);
} else {
for_each_possible_cpu(cpu) {
int mct_irq = mct_irqs[MCT_L0_IRQ + cpu];
struct mct_clock_event_device *pcpu_mevt =
per_cpu_ptr(&percpu_mct_tick, cpu);
pcpu_mevt->evt.irq = -1;
irq_set_status_flags(mct_irq, IRQ_NOAUTOEN);
if (request_irq(mct_irq,
exynos4_mct_tick_isr,
IRQF_TIMER | IRQF_NOBALANCING,
pcpu_mevt->name, pcpu_mevt)) {
pr_err("exynos-mct: cannot register IRQ (cpu%d)\n",
cpu);
continue;
}
pcpu_mevt->evt.irq = mct_irq;
}
}
/* Install hotplug callbacks which configure the timer on this CPU */
err = cpuhp_setup_state(CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
"clockevents/exynos4/mct_timer:starting",
exynos4_mct_starting_cpu,
exynos4_mct_dying_cpu);
if (err)
goto out_irq;
return 0;
out_irq:
if (mct_int_type == MCT_INT_PPI) {
free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
} else {
for_each_possible_cpu(cpu) {
struct mct_clock_event_device *pcpu_mevt =
per_cpu_ptr(&percpu_mct_tick, cpu);
if (pcpu_mevt->evt.irq != -1) {
free_irq(pcpu_mevt->evt.irq, pcpu_mevt);
pcpu_mevt->evt.irq = -1;
}
}
}
return err;
}
static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
{
u32 nr_irqs, i;
int ret;
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);
ret = exynos4_timer_resources(np, of_iomap(np, 0));
if (ret)
return ret;
ret = exynos4_clocksource_init();
if (ret)
return ret;
return exynos4_clockevent_init();
}
static int __init mct_init_spi(struct device_node *np)
{
return mct_init_dt(np, MCT_INT_SPI);
}
static int __init mct_init_ppi(struct device_node *np)
{
return mct_init_dt(np, MCT_INT_PPI);
}
TIMER_OF_DECLARE(exynos4210, "samsung,exynos4210-mct", mct_init_spi);
TIMER_OF_DECLARE(exynos4412, "samsung,exynos4412-mct", mct_init_ppi);