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/*
*
* Copyright (C) 2007 Google, Inc.
* Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved.
*
* 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/clocksource.h>
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <asm/mach/time.h>
#include <asm/hardware/gic.h>
#include <asm/localtimer.h>
#include <mach/msm_iomap.h>
#include <mach/cpu.h>
#include <mach/board.h>
#define TIMER_MATCH_VAL 0x0000
#define TIMER_COUNT_VAL 0x0004
#define TIMER_ENABLE 0x0008
#define TIMER_ENABLE_CLR_ON_MATCH_EN BIT(1)
#define TIMER_ENABLE_EN BIT(0)
#define TIMER_CLEAR 0x000C
#define DGT_CLK_CTL 0x0034
#define DGT_CLK_CTL_DIV_4 0x3
#define GPT_HZ 32768
#define MSM_DGT_SHIFT 5
static void __iomem *event_base;
static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
/* Stop the timer tick */
if (evt->mode == CLOCK_EVT_MODE_ONESHOT) {
u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
ctrl &= ~TIMER_ENABLE_EN;
writel_relaxed(ctrl, event_base + TIMER_ENABLE);
}
evt->event_handler(evt);
return IRQ_HANDLED;
}
static int msm_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
writel_relaxed(0, event_base + TIMER_CLEAR);
writel_relaxed(cycles, event_base + TIMER_MATCH_VAL);
writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE);
return 0;
}
static void msm_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
u32 ctrl;
ctrl = readl_relaxed(event_base + TIMER_ENABLE);
ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN);
switch (mode) {
case CLOCK_EVT_MODE_RESUME:
case CLOCK_EVT_MODE_PERIODIC:
break;
case CLOCK_EVT_MODE_ONESHOT:
/* Timer is enabled in set_next_event */
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
break;
}
writel_relaxed(ctrl, event_base + TIMER_ENABLE);
}
static struct clock_event_device msm_clockevent = {
.name = "gp_timer",
.features = CLOCK_EVT_FEAT_ONESHOT,
.rating = 200,
.set_next_event = msm_timer_set_next_event,
.set_mode = msm_timer_set_mode,
};
static union {
struct clock_event_device *evt;
struct clock_event_device __percpu **percpu_evt;
} msm_evt;
static void __iomem *source_base;
static cycle_t msm_read_timer_count(struct clocksource *cs)
{
return readl_relaxed(source_base + TIMER_COUNT_VAL);
}
static cycle_t msm_read_timer_count_shift(struct clocksource *cs)
{
/*
* Shift timer count down by a constant due to unreliable lower bits
* on some targets.
*/
return msm_read_timer_count(cs) >> MSM_DGT_SHIFT;
}
static struct clocksource msm_clocksource = {
.name = "dg_timer",
.rating = 300,
.read = msm_read_timer_count,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
#ifdef CONFIG_LOCAL_TIMERS
static int __cpuinit msm_local_timer_setup(struct clock_event_device *evt)
{
/* Use existing clock_event for cpu 0 */
if (!smp_processor_id())
return 0;
writel_relaxed(0, event_base + TIMER_ENABLE);
writel_relaxed(0, event_base + TIMER_CLEAR);
writel_relaxed(~0, event_base + TIMER_MATCH_VAL);
evt->irq = msm_clockevent.irq;
evt->name = "local_timer";
evt->features = msm_clockevent.features;
evt->rating = msm_clockevent.rating;
evt->set_mode = msm_timer_set_mode;
evt->set_next_event = msm_timer_set_next_event;
evt->shift = msm_clockevent.shift;
evt->mult = div_sc(GPT_HZ, NSEC_PER_SEC, evt->shift);
evt->max_delta_ns = clockevent_delta2ns(0xf0000000, evt);
evt->min_delta_ns = clockevent_delta2ns(4, evt);
*__this_cpu_ptr(msm_evt.percpu_evt) = evt;
clockevents_register_device(evt);
enable_percpu_irq(evt->irq, 0);
return 0;
}
static void msm_local_timer_stop(struct clock_event_device *evt)
{
evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
disable_percpu_irq(evt->irq);
}
static struct local_timer_ops msm_local_timer_ops __cpuinitdata = {
.setup = msm_local_timer_setup,
.stop = msm_local_timer_stop,
};
#endif /* CONFIG_LOCAL_TIMERS */
static void __init msm_timer_init(void)
{
struct clock_event_device *ce = &msm_clockevent;
struct clocksource *cs = &msm_clocksource;
int res;
u32 dgt_hz;
if (cpu_is_msm7x01()) {
event_base = MSM_CSR_BASE;
source_base = MSM_CSR_BASE + 0x10;
dgt_hz = 19200000 >> MSM_DGT_SHIFT; /* 600 KHz */
cs->read = msm_read_timer_count_shift;
cs->mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT));
} else if (cpu_is_msm7x30()) {
event_base = MSM_CSR_BASE + 0x04;
source_base = MSM_CSR_BASE + 0x24;
dgt_hz = 24576000 / 4;
} else if (cpu_is_qsd8x50()) {
event_base = MSM_CSR_BASE;
source_base = MSM_CSR_BASE + 0x10;
dgt_hz = 19200000 / 4;
} else if (cpu_is_msm8x60() || cpu_is_msm8960()) {
event_base = MSM_TMR_BASE + 0x04;
/* Use CPU0's timer as the global clock source. */
source_base = MSM_TMR0_BASE + 0x24;
dgt_hz = 27000000 / 4;
writel_relaxed(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
} else
BUG();
writel_relaxed(0, event_base + TIMER_ENABLE);
writel_relaxed(0, event_base + TIMER_CLEAR);
writel_relaxed(~0, event_base + TIMER_MATCH_VAL);
ce->cpumask = cpumask_of(0);
ce->irq = INT_GP_TIMER_EXP;
clockevents_config_and_register(ce, GPT_HZ, 4, 0xffffffff);
if (cpu_is_msm8x60() || cpu_is_msm8960()) {
msm_evt.percpu_evt = alloc_percpu(struct clock_event_device *);
if (!msm_evt.percpu_evt) {
pr_err("memory allocation failed for %s\n", ce->name);
goto err;
}
*__this_cpu_ptr(msm_evt.percpu_evt) = ce;
res = request_percpu_irq(ce->irq, msm_timer_interrupt,
ce->name, msm_evt.percpu_evt);
if (!res) {
enable_percpu_irq(ce->irq, 0);
#ifdef CONFIG_LOCAL_TIMERS
local_timer_register(&msm_local_timer_ops);
#endif
}
} else {
msm_evt.evt = ce;
res = request_irq(ce->irq, msm_timer_interrupt,
IRQF_TIMER | IRQF_NOBALANCING |
IRQF_TRIGGER_RISING, ce->name, &msm_evt.evt);
}
if (res)
pr_err("request_irq failed for %s\n", ce->name);
err:
writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
res = clocksource_register_hz(cs, dgt_hz);
if (res)
pr_err("clocksource_register failed\n");
}
struct sys_timer msm_timer = {
.init = msm_timer_init
};
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