- 根目录:
- arch
- arm
- mach-omap2
- timer.c
/*
* linux/arch/arm/mach-omap2/timer.c
*
* OMAP2 GP timer support.
*
* Copyright (C) 2009 Nokia Corporation
*
* Update to use new clocksource/clockevent layers
* Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
* Copyright (C) 2007 MontaVista Software, Inc.
*
* Original driver:
* Copyright (C) 2005 Nokia Corporation
* Author: Paul Mundt <paul.mundt@nokia.com>
* Juha Yrjölä <juha.yrjola@nokia.com>
* OMAP Dual-mode timer framework support by Timo Teras
*
* Some parts based off of TI's 24xx code:
*
* Copyright (C) 2004-2009 Texas Instruments, Inc.
*
* Roughly modelled after the OMAP1 MPU timer code.
* Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/platform_data/dmtimer-omap.h>
#include <linux/sched_clock.h>
#include <asm/mach/time.h>
#include <asm/smp_twd.h>
#include "omap_hwmod.h"
#include "omap_device.h"
#include <plat/counter-32k.h>
#include <plat/dmtimer.h>
#include "omap-pm.h"
#include "soc.h"
#include "common.h"
#include "control.h"
#include "powerdomain.h"
#include "omap-secure.h"
#define REALTIME_COUNTER_BASE 0x48243200
#define INCREMENTER_NUMERATOR_OFFSET 0x10
#define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14
#define NUMERATOR_DENUMERATOR_MASK 0xfffff000
/* Clockevent code */
static struct omap_dm_timer clkev;
static struct clock_event_device clockevent_gpt;
#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
static unsigned long arch_timer_freq;
void set_cntfreq(void)
{
omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
}
#endif
static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = &clockevent_gpt;
__omap_dm_timer_write_status(&clkev, OMAP_TIMER_INT_OVERFLOW);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction omap2_gp_timer_irq = {
.name = "gp_timer",
.flags = IRQF_TIMER | IRQF_IRQPOLL,
.handler = omap2_gp_timer_interrupt,
};
static int omap2_gp_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
__omap_dm_timer_load_start(&clkev, OMAP_TIMER_CTRL_ST,
0xffffffff - cycles, OMAP_TIMER_POSTED);
return 0;
}
static int omap2_gp_timer_shutdown(struct clock_event_device *evt)
{
__omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
return 0;
}
static int omap2_gp_timer_set_periodic(struct clock_event_device *evt)
{
u32 period;
__omap_dm_timer_stop(&clkev, OMAP_TIMER_POSTED, clkev.rate);
period = clkev.rate / HZ;
period -= 1;
/* Looks like we need to first set the load value separately */
__omap_dm_timer_write(&clkev, OMAP_TIMER_LOAD_REG, 0xffffffff - period,
OMAP_TIMER_POSTED);
__omap_dm_timer_load_start(&clkev,
OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
0xffffffff - period, OMAP_TIMER_POSTED);
return 0;
}
static struct clock_event_device clockevent_gpt = {
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.rating = 300,
.set_next_event = omap2_gp_timer_set_next_event,
.set_state_shutdown = omap2_gp_timer_shutdown,
.set_state_periodic = omap2_gp_timer_set_periodic,
.set_state_oneshot = omap2_gp_timer_shutdown,
.tick_resume = omap2_gp_timer_shutdown,
};
static struct property device_disabled = {
.name = "status",
.length = sizeof("disabled"),
.value = "disabled",
};
static const struct of_device_id omap_timer_match[] __initconst = {
{ .compatible = "ti,omap2420-timer", },
{ .compatible = "ti,omap3430-timer", },
{ .compatible = "ti,omap4430-timer", },
{ .compatible = "ti,omap5430-timer", },
{ .compatible = "ti,dm814-timer", },
{ .compatible = "ti,dm816-timer", },
{ .compatible = "ti,am335x-timer", },
{ .compatible = "ti,am335x-timer-1ms", },
{ }
};
/**
* omap_get_timer_dt - get a timer using device-tree
* @match - device-tree match structure for matching a device type
* @property - optional timer property to match
*
* Helper function to get a timer during early boot using device-tree for use
* as kernel system timer. Optionally, the property argument can be used to
* select a timer with a specific property. Once a timer is found then mark
* the timer node in device-tree as disabled, to prevent the kernel from
* registering this timer as a platform device and so no one else can use it.
*/
static struct device_node * __init omap_get_timer_dt(const struct of_device_id *match,
const char *property)
{
struct device_node *np;
for_each_matching_node(np, match) {
if (!of_device_is_available(np))
continue;
if (property && !of_get_property(np, property, NULL))
continue;
if (!property && (of_get_property(np, "ti,timer-alwon", NULL) ||
of_get_property(np, "ti,timer-dsp", NULL) ||
of_get_property(np, "ti,timer-pwm", NULL) ||
of_get_property(np, "ti,timer-secure", NULL)))
continue;
if (!of_device_is_compatible(np, "ti,omap-counter32k"))
of_add_property(np, &device_disabled);
return np;
}
return NULL;
}
/**
* omap_dmtimer_init - initialisation function when device tree is used
*
* For secure OMAP3 devices, timers with device type "timer-secure" cannot
* be used by the kernel as they are reserved. Therefore, to prevent the
* kernel registering these devices remove them dynamically from the device
* tree on boot.
*/
static void __init omap_dmtimer_init(void)
{
struct device_node *np;
if (!cpu_is_omap34xx())
return;
/* If we are a secure device, remove any secure timer nodes */
if ((omap_type() != OMAP2_DEVICE_TYPE_GP)) {
np = omap_get_timer_dt(omap_timer_match, "ti,timer-secure");
of_node_put(np);
}
}
/**
* omap_dm_timer_get_errata - get errata flags for a timer
*
* Get the timer errata flags that are specific to the OMAP device being used.
*/
static u32 __init omap_dm_timer_get_errata(void)
{
if (cpu_is_omap24xx())
return 0;
return OMAP_TIMER_ERRATA_I103_I767;
}
static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
const char *fck_source,
const char *property,
const char **timer_name,
int posted)
{
char name[10]; /* 10 = sizeof("gptXX_Xck0") */
const char *oh_name = NULL;
struct device_node *np;
struct omap_hwmod *oh;
struct resource irq, mem;
struct clk *src;
int r = 0;
if (of_have_populated_dt()) {
np = omap_get_timer_dt(omap_timer_match, property);
if (!np)
return -ENODEV;
of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
if (!oh_name)
return -ENODEV;
timer->irq = irq_of_parse_and_map(np, 0);
if (!timer->irq)
return -ENXIO;
timer->io_base = of_iomap(np, 0);
of_node_put(np);
} else {
if (omap_dm_timer_reserve_systimer(timer->id))
return -ENODEV;
sprintf(name, "timer%d", timer->id);
oh_name = name;
}
oh = omap_hwmod_lookup(oh_name);
if (!oh)
return -ENODEV;
*timer_name = oh->name;
if (!of_have_populated_dt()) {
r = omap_hwmod_get_resource_byname(oh, IORESOURCE_IRQ, NULL,
&irq);
if (r)
return -ENXIO;
timer->irq = irq.start;
r = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL,
&mem);
if (r)
return -ENXIO;
/* Static mapping, never released */
timer->io_base = ioremap(mem.start, mem.end - mem.start);
}
if (!timer->io_base)
return -ENXIO;
/* After the dmtimer is using hwmod these clocks won't be needed */
timer->fclk = clk_get(NULL, omap_hwmod_get_main_clk(oh));
if (IS_ERR(timer->fclk))
return PTR_ERR(timer->fclk);
src = clk_get(NULL, fck_source);
if (IS_ERR(src))
return PTR_ERR(src);
WARN(clk_set_parent(timer->fclk, src) < 0,
"Cannot set timer parent clock, no PLL clock driver?");
clk_put(src);
omap_hwmod_setup_one(oh_name);
omap_hwmod_enable(oh);
__omap_dm_timer_init_regs(timer);
if (posted)
__omap_dm_timer_enable_posted(timer);
/* Check that the intended posted configuration matches the actual */
if (posted != timer->posted)
return -EINVAL;
timer->rate = clk_get_rate(timer->fclk);
timer->reserved = 1;
return r;
}
#if !defined(CONFIG_SMP) && defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
void tick_broadcast(const struct cpumask *mask)
{
}
#endif
static void __init omap2_gp_clockevent_init(int gptimer_id,
const char *fck_source,
const char *property)
{
int res;
clkev.id = gptimer_id;
clkev.errata = omap_dm_timer_get_errata();
/*
* For clock-event timers we never read the timer counter and
* so we are not impacted by errata i103 and i767. Therefore,
* we can safely ignore this errata for clock-event timers.
*/
__omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);
res = omap_dm_timer_init_one(&clkev, fck_source, property,
&clockevent_gpt.name, OMAP_TIMER_POSTED);
BUG_ON(res);
omap2_gp_timer_irq.dev_id = &clkev;
setup_irq(clkev.irq, &omap2_gp_timer_irq);
__omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
clockevent_gpt.cpumask = cpu_possible_mask;
clockevent_gpt.irq = omap_dm_timer_get_irq(&clkev);
clockevents_config_and_register(&clockevent_gpt, clkev.rate,
3, /* Timer internal resynch latency */
0xffffffff);
pr_info("OMAP clockevent source: %s at %lu Hz\n", clockevent_gpt.name,
clkev.rate);
}
/* Clocksource code */
static struct omap_dm_timer clksrc;
static bool use_gptimer_clksrc __initdata;
/*
* clocksource
*/
static cycle_t clocksource_read_cycles(struct clocksource *cs)
{
return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
OMAP_TIMER_NONPOSTED);
}
static struct clocksource clocksource_gpt = {
.rating = 300,
.read = clocksource_read_cycles,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static u64 notrace dmtimer_read_sched_clock(void)
{
if (clksrc.reserved)
return __omap_dm_timer_read_counter(&clksrc,
OMAP_TIMER_NONPOSTED);
return 0;
}
static const struct of_device_id omap_counter_match[] __initconst = {
{ .compatible = "ti,omap-counter32k", },
{ }
};
/* Setup free-running counter for clocksource */
static int __init __maybe_unused omap2_sync32k_clocksource_init(void)
{
int ret;
struct device_node *np = NULL;
struct omap_hwmod *oh;
const char *oh_name = "counter_32k";
/*
* If device-tree is present, then search the DT blob
* to see if the 32kHz counter is supported.
*/
if (of_have_populated_dt()) {
np = omap_get_timer_dt(omap_counter_match, NULL);
if (!np)
return -ENODEV;
of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
if (!oh_name)
return -ENODEV;
}
/*
* First check hwmod data is available for sync32k counter
*/
oh = omap_hwmod_lookup(oh_name);
if (!oh || oh->slaves_cnt == 0)
return -ENODEV;
omap_hwmod_setup_one(oh_name);
ret = omap_hwmod_enable(oh);
if (ret) {
pr_warn("%s: failed to enable counter_32k module (%d)\n",
__func__, ret);
return ret;
}
if (!of_have_populated_dt()) {
void __iomem *vbase;
vbase = omap_hwmod_get_mpu_rt_va(oh);
ret = omap_init_clocksource_32k(vbase);
if (ret) {
pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
__func__, ret);
omap_hwmod_idle(oh);
}
}
return ret;
}
static void __init omap2_gptimer_clocksource_init(int gptimer_id,
const char *fck_source,
const char *property)
{
int res;
clksrc.id = gptimer_id;
clksrc.errata = omap_dm_timer_get_errata();
res = omap_dm_timer_init_one(&clksrc, fck_source, property,
&clocksource_gpt.name,
OMAP_TIMER_NONPOSTED);
BUG_ON(res);
__omap_dm_timer_load_start(&clksrc,
OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
OMAP_TIMER_NONPOSTED);
sched_clock_register(dmtimer_read_sched_clock, 32, clksrc.rate);
if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
pr_err("Could not register clocksource %s\n",
clocksource_gpt.name);
else
pr_info("OMAP clocksource: %s at %lu Hz\n",
clocksource_gpt.name, clksrc.rate);
}
static void __init __omap_sync32k_timer_init(int clkev_nr, const char *clkev_src,
const char *clkev_prop, int clksrc_nr, const char *clksrc_src,
const char *clksrc_prop, bool gptimer)
{
omap_clk_init();
omap_dmtimer_init();
omap2_gp_clockevent_init(clkev_nr, clkev_src, clkev_prop);
/* Enable the use of clocksource="gp_timer" kernel parameter */
if (use_gptimer_clksrc || gptimer)
omap2_gptimer_clocksource_init(clksrc_nr, clksrc_src,
clksrc_prop);
else
omap2_sync32k_clocksource_init();
}
void __init omap_init_time(void)
{
__omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon",
2, "timer_sys_ck", NULL, false);
if (of_have_populated_dt())
clocksource_probe();
}
#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM43XX)
void __init omap3_secure_sync32k_timer_init(void)
{
__omap_sync32k_timer_init(12, "secure_32k_fck", "ti,timer-secure",
2, "timer_sys_ck", NULL, false);
}
#endif /* CONFIG_ARCH_OMAP3 */
#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_SOC_AM33XX)
void __init omap3_gptimer_timer_init(void)
{
__omap_sync32k_timer_init(2, "timer_sys_ck", NULL,
1, "timer_sys_ck", "ti,timer-alwon", true);
}
#endif
#if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5) || \
defined(CONFIG_SOC_DRA7XX) || defined(CONFIG_SOC_AM43XX)
static void __init omap4_sync32k_timer_init(void)
{
__omap_sync32k_timer_init(1, "timer_32k_ck", "ti,timer-alwon",
2, "sys_clkin_ck", NULL, false);
}
void __init omap4_local_timer_init(void)
{
omap4_sync32k_timer_init();
clocksource_probe();
}
#endif
#if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
/*
* The realtime counter also called master counter, is a free-running
* counter, which is related to real time. It produces the count used
* by the CPU local timer peripherals in the MPU cluster. The timer counts
* at a rate of 6.144 MHz. Because the device operates on different clocks
* in different power modes, the master counter shifts operation between
* clocks, adjusting the increment per clock in hardware accordingly to
* maintain a constant count rate.
*/
static void __init realtime_counter_init(void)
{
#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
void __iomem *base;
static struct clk *sys_clk;
unsigned long rate;
unsigned int reg;
unsigned long long num, den;
base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
if (!base) {
pr_err("%s: ioremap failed\n", __func__);
return;
}
sys_clk = clk_get(NULL, "sys_clkin");
if (IS_ERR(sys_clk)) {
pr_err("%s: failed to get system clock handle\n", __func__);
iounmap(base);
return;
}
rate = clk_get_rate(sys_clk);
if (soc_is_dra7xx()) {
/*
* Errata i856 says the 32.768KHz crystal does not start at
* power on, so the CPU falls back to an emulated 32KHz clock
* based on sysclk / 610 instead. This causes the master counter
* frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
* (OR sysclk * 75 / 244)
*
* This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
* Of course any board built without a populated 32.768KHz
* crystal would also need this fix even if the CPU is fixed
* later.
*
* Either case can be detected by using the two speedselect bits
* If they are not 0, then the 32.768KHz clock driving the
* coarse counter that corrects the fine counter every time it
* ticks is actually rate/610 rather than 32.768KHz and we
* should compensate to avoid the 570ppm (at 20MHz, much worse
* at other rates) too fast system time.
*/
reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
if (reg & DRA7_SPEEDSELECT_MASK) {
num = 75;
den = 244;
goto sysclk1_based;
}
}
/* Numerator/denumerator values refer TRM Realtime Counter section */
switch (rate) {
case 12000000:
num = 64;
den = 125;
break;
case 13000000:
num = 768;
den = 1625;
break;
case 19200000:
num = 8;
den = 25;
break;
case 20000000:
num = 192;
den = 625;
break;
case 26000000:
num = 384;
den = 1625;
break;
case 27000000:
num = 256;
den = 1125;
break;
case 38400000:
default:
/* Program it for 38.4 MHz */
num = 4;
den = 25;
break;
}
sysclk1_based:
/* Program numerator and denumerator registers */
reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
NUMERATOR_DENUMERATOR_MASK;
reg |= num;
writel_relaxed(reg, base + INCREMENTER_NUMERATOR_OFFSET);
reg = readl_relaxed(base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET) &
NUMERATOR_DENUMERATOR_MASK;
reg |= den;
writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
set_cntfreq();
iounmap(base);
#endif
}
void __init omap5_realtime_timer_init(void)
{
omap4_sync32k_timer_init();
realtime_counter_init();
clocksource_probe();
}
#endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
/**
* omap_timer_init - build and register timer device with an
* associated timer hwmod
* @oh: timer hwmod pointer to be used to build timer device
* @user: parameter that can be passed from calling hwmod API
*
* Called by omap_hwmod_for_each_by_class to register each of the timer
* devices present in the system. The number of timer devices is known
* by parsing through the hwmod database for a given class name. At the
* end of function call memory is allocated for timer device and it is
* registered to the framework ready to be proved by the driver.
*/
static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
{
int id;
int ret = 0;
char *name = "omap_timer";
struct dmtimer_platform_data *pdata;
struct platform_device *pdev;
struct omap_timer_capability_dev_attr *timer_dev_attr;
pr_debug("%s: %s\n", __func__, oh->name);
/* on secure device, do not register secure timer */
timer_dev_attr = oh->dev_attr;
if (omap_type() != OMAP2_DEVICE_TYPE_GP && timer_dev_attr)
if (timer_dev_attr->timer_capability == OMAP_TIMER_SECURE)
return ret;
pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
if (!pdata) {
pr_err("%s: No memory for [%s]\n", __func__, oh->name);
return -ENOMEM;
}
/*
* Extract the IDs from name field in hwmod database
* and use the same for constructing ids' for the
* timer devices. In a way, we are avoiding usage of
* static variable witin the function to do the same.
* CAUTION: We have to be careful and make sure the
* name in hwmod database does not change in which case
* we might either make corresponding change here or
* switch back static variable mechanism.
*/
sscanf(oh->name, "timer%2d", &id);
if (timer_dev_attr)
pdata->timer_capability = timer_dev_attr->timer_capability;
pdata->timer_errata = omap_dm_timer_get_errata();
pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata));
if (IS_ERR(pdev)) {
pr_err("%s: Can't build omap_device for %s: %s.\n",
__func__, name, oh->name);
ret = -EINVAL;
}
kfree(pdata);
return ret;
}
/**
* omap2_dm_timer_init - top level regular device initialization
*
* Uses dedicated hwmod api to parse through hwmod database for
* given class name and then build and register the timer device.
*/
static int __init omap2_dm_timer_init(void)
{
int ret;
/* If dtb is there, the devices will be created dynamically */
if (of_have_populated_dt())
return -ENODEV;
ret = omap_hwmod_for_each_by_class("timer", omap_timer_init, NULL);
if (unlikely(ret)) {
pr_err("%s: device registration failed.\n", __func__);
return -EINVAL;
}
return 0;
}
omap_arch_initcall(omap2_dm_timer_init);
/**
* omap2_override_clocksource - clocksource override with user configuration
*
* Allows user to override default clocksource, using kernel parameter
* clocksource="gp_timer" (For all OMAP2PLUS architectures)
*
* Note that, here we are using same standard kernel parameter "clocksource=",
* and not introducing any OMAP specific interface.
*/
static int __init omap2_override_clocksource(char *str)
{
if (!str)
return 0;
/*
* For OMAP architecture, we only have two options
* - sync_32k (default)
* - gp_timer (sys_clk based)
*/
if (!strcmp(str, "gp_timer"))
use_gptimer_clksrc = true;
return 0;
}
early_param("clocksource", omap2_override_clocksource);