linux/arch/arm/mach-msm/timer.c

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/* linux/arch/arm/mach-msm/timer.c
*
* Copyright (C) 2007 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/init.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <asm/mach/time.h>
#include <asm/hardware/gic.h>
#include <mach/msm_iomap.h>
#include <mach/cpu.h>
#define TIMER_MATCH_VAL 0x0000
#define TIMER_COUNT_VAL 0x0004
#define TIMER_ENABLE 0x0008
#define TIMER_ENABLE_CLR_ON_MATCH_EN 2
#define TIMER_ENABLE_EN 1
#define TIMER_CLEAR 0x000C
#define DGT_CLK_CTL 0x0034
enum {
DGT_CLK_CTL_DIV_1 = 0,
DGT_CLK_CTL_DIV_2 = 1,
DGT_CLK_CTL_DIV_3 = 2,
DGT_CLK_CTL_DIV_4 = 3,
};
#define CSR_PROTECTION 0x0020
#define CSR_PROTECTION_EN 1
#define GPT_HZ 32768
enum timer_location {
LOCAL_TIMER = 0,
GLOBAL_TIMER = 1,
};
#define MSM_GLOBAL_TIMER MSM_CLOCK_DGT
/* TODO: Remove these ifdefs */
#if defined(CONFIG_ARCH_QSD8X50)
#define DGT_HZ (19200000 / 4) /* 19.2 MHz / 4 by default */
#define MSM_DGT_SHIFT (0)
#elif defined(CONFIG_ARCH_MSM7X30)
#define DGT_HZ (24576000 / 4) /* 24.576 MHz (LPXO) / 4 by default */
#define MSM_DGT_SHIFT (0)
#elif defined(CONFIG_ARCH_MSM8X60) || defined(CONFIG_ARCH_MSM8960)
#define DGT_HZ (27000000 / 4) /* 27 MHz (PXO) / 4 by default */
#define MSM_DGT_SHIFT (0)
#else
#define DGT_HZ 19200000 /* 19.2 MHz or 600 KHz after shift */
#define MSM_DGT_SHIFT (5)
#endif
struct msm_clock {
struct clock_event_device clockevent;
struct clocksource clocksource;
unsigned int irq;
void __iomem *regbase;
uint32_t freq;
uint32_t shift;
void __iomem *global_counter;
void __iomem *local_counter;
union {
struct clock_event_device *evt;
struct clock_event_device __percpu **percpu_evt;
};
};
enum {
MSM_CLOCK_GPT,
MSM_CLOCK_DGT,
NR_TIMERS,
};
static struct msm_clock msm_clocks[];
static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
if (evt->event_handler == NULL)
return IRQ_HANDLED;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static cycle_t msm_read_timer_count(struct clocksource *cs)
{
struct msm_clock *clk = container_of(cs, struct msm_clock, clocksource);
/*
* Shift timer count down by a constant due to unreliable lower bits
* on some targets.
*/
return readl(clk->global_counter) >> clk->shift;
}
static struct msm_clock *clockevent_to_clock(struct clock_event_device *evt)
{
#ifdef CONFIG_SMP
int i;
for (i = 0; i < NR_TIMERS; i++)
if (evt == &(msm_clocks[i].clockevent))
return &msm_clocks[i];
return &msm_clocks[MSM_GLOBAL_TIMER];
#else
return container_of(evt, struct msm_clock, clockevent);
#endif
}
static int msm_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
struct msm_clock *clock = clockevent_to_clock(evt);
uint32_t now = readl(clock->local_counter);
uint32_t alarm = now + (cycles << clock->shift);
writel(alarm, clock->regbase + TIMER_MATCH_VAL);
return 0;
}
static void msm_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
struct msm_clock *clock = clockevent_to_clock(evt);
switch (mode) {
case CLOCK_EVT_MODE_RESUME:
case CLOCK_EVT_MODE_PERIODIC:
break;
case CLOCK_EVT_MODE_ONESHOT:
writel(TIMER_ENABLE_EN, clock->regbase + TIMER_ENABLE);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
writel(0, clock->regbase + TIMER_ENABLE);
break;
}
}
static struct msm_clock msm_clocks[] = {
[MSM_CLOCK_GPT] = {
.clockevent = {
.name = "gp_timer",
.features = CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.rating = 200,
.set_next_event = msm_timer_set_next_event,
.set_mode = msm_timer_set_mode,
},
.clocksource = {
.name = "gp_timer",
.rating = 200,
.read = msm_read_timer_count,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
},
.irq = INT_GP_TIMER_EXP,
.freq = GPT_HZ,
},
[MSM_CLOCK_DGT] = {
.clockevent = {
.name = "dg_timer",
.features = CLOCK_EVT_FEAT_ONESHOT,
.shift = 32 + MSM_DGT_SHIFT,
.rating = 300,
.set_next_event = msm_timer_set_next_event,
.set_mode = msm_timer_set_mode,
},
.clocksource = {
.name = "dg_timer",
.rating = 300,
.read = msm_read_timer_count,
.mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
},
.irq = INT_DEBUG_TIMER_EXP,
.freq = DGT_HZ >> MSM_DGT_SHIFT,
.shift = MSM_DGT_SHIFT,
}
};
static void __init msm_timer_init(void)
{
int i;
int res;
int global_offset = 0;
if (cpu_is_msm7x01()) {
msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
} else if (cpu_is_msm7x30()) {
msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE + 0x04;
msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x24;
} else if (cpu_is_qsd8x50()) {
msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
} else if (cpu_is_msm8x60() || cpu_is_msm8960()) {
msm_clocks[MSM_CLOCK_GPT].regbase = MSM_TMR_BASE + 0x04;
msm_clocks[MSM_CLOCK_DGT].regbase = MSM_TMR_BASE + 0x24;
/* Use CPU0's timer as the global timer. */
global_offset = MSM_TMR0_BASE - MSM_TMR_BASE;
} else
BUG();
#ifdef CONFIG_ARCH_MSM_SCORPIONMP
writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
#endif
for (i = 0; i < ARRAY_SIZE(msm_clocks); i++) {
struct msm_clock *clock = &msm_clocks[i];
struct clock_event_device *ce = &clock->clockevent;
struct clocksource *cs = &clock->clocksource;
clock->local_counter = clock->regbase + TIMER_COUNT_VAL;
clock->global_counter = clock->local_counter + global_offset;
writel(0, clock->regbase + TIMER_ENABLE);
writel(0, clock->regbase + TIMER_CLEAR);
writel(~0, clock->regbase + TIMER_MATCH_VAL);
ce->mult = div_sc(clock->freq, NSEC_PER_SEC, ce->shift);
/* allow at least 10 seconds to notice that the timer wrapped */
ce->max_delta_ns =
clockevent_delta2ns(0xf0000000 >> clock->shift, ce);
/* 4 gets rounded down to 3 */
ce->min_delta_ns = clockevent_delta2ns(4, ce);
ce->cpumask = cpumask_of(0);
res = clocksource_register_hz(cs, clock->freq);
if (res)
printk(KERN_ERR "msm_timer_init: clocksource_register "
"failed for %s\n", cs->name);
ce->irq = clock->irq;
if (cpu_is_msm8x60() || cpu_is_msm8960()) {
clock->percpu_evt = alloc_percpu(struct clock_event_device *);
if (!clock->percpu_evt) {
pr_err("msm_timer_init: memory allocation "
"failed for %s\n", ce->name);
continue;
}
*__this_cpu_ptr(clock->percpu_evt) = ce;
res = request_percpu_irq(ce->irq, msm_timer_interrupt,
ce->name, clock->percpu_evt);
if (!res)
enable_percpu_irq(ce->irq, 0);
} else {
clock->evt = ce;
res = request_irq(ce->irq, msm_timer_interrupt,
IRQF_TIMER | IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
ce->name, &clock->evt);
}
if (res)
pr_err("msm_timer_init: request_irq failed for %s\n",
ce->name);
clockevents_register_device(ce);
}
}
#ifdef CONFIG_SMP
int __cpuinit local_timer_setup(struct clock_event_device *evt)
{
static bool local_timer_inited;
struct msm_clock *clock = &msm_clocks[MSM_GLOBAL_TIMER];
/* Use existing clock_event for cpu 0 */
if (!smp_processor_id())
return 0;
writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
if (!local_timer_inited) {
writel(0, clock->regbase + TIMER_ENABLE);
writel(0, clock->regbase + TIMER_CLEAR);
writel(~0, clock->regbase + TIMER_MATCH_VAL);
local_timer_inited = true;
}
evt->irq = clock->irq;
evt->name = "local_timer";
evt->features = CLOCK_EVT_FEAT_ONESHOT;
evt->rating = clock->clockevent.rating;
evt->set_mode = msm_timer_set_mode;
evt->set_next_event = msm_timer_set_next_event;
evt->shift = clock->clockevent.shift;
evt->mult = div_sc(clock->freq, NSEC_PER_SEC, evt->shift);
evt->max_delta_ns =
clockevent_delta2ns(0xf0000000 >> clock->shift, evt);
evt->min_delta_ns = clockevent_delta2ns(4, evt);
*__this_cpu_ptr(clock->percpu_evt) = evt;
enable_percpu_irq(evt->irq, 0);
clockevents_register_device(evt);
return 0;
}
void local_timer_stop(struct clock_event_device *evt)
{
evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
disable_percpu_irq(evt->irq);
}
#endif
struct sys_timer msm_timer = {
.init = msm_timer_init
};