kernel-fxtec-pro1x/arch/arm/mach-omap2/timer.c
Vaibhav Hiremath dbc3982ae2 ARM: OMAP2+: timer: Fix crash due to wrong arg to __omap_dm_timer_read_counter
Commit 2f0778af (ARM: 7205/2: sched_clock: allow sched_clock to be
selected at runtime) had a typo for the case when CONFIG_OMAP_32K_TIMER
is not set.

In dmtimer_read_sched_clock(), wrong argument was getting passed to
__omap_dm_timer_read_counter() function call; instead of "&clksrc",
we were passing "clksrc.io_base", which results into kernel crash.

To reproduce kernel crash, just disable the CONFIG_OMAP_32K_TIMER config
option (and DEBUG_LL) and build/boot the kernel.
This will use dmtimer as a kernel clocksource and lead to kernel
crash during boot  -

[    0.000000] OMAP clocksource: GPTIMER2 at 26000000 Hz
[    0.000000] sched_clock: 32 bits at 26MHz, resolution 38ns, wraps every
165191ms
[    0.000000] Unable to handle kernel paging request at virtual address
00030ef1
[    0.000000] pgd = c0004000
[    0.000000] [00030ef1] *pgd=00000000
[    0.000000] Internal error: Oops: 5 [#1] SMP
[    0.000000] Modules linked in:
[    0.000000] CPU: 0    Not tainted  (3.3.0-rc1-11574-g0c76665-dirty #3)
[    0.000000] PC is at dmtimer_read_sched_clock+0x18/0x4c
[    0.000000] LR is at update_sched_clock+0x10/0x84
[    0.000000] pc : [<c00243b8>]    lr : [<c0018684>]    psr: 200001d3
[    0.000000] sp : c0641f38  ip : c0641e18  fp : 0000000a
[    0.000000] r10: 151c3303  r9 : 00000026  r8 : 76276259
[    0.000000] r7 : 00028547  r6 : c065ac80  r5 : 431bde82  r4 : c0655968
[    0.000000] r3 : 00030ef1  r2 : fb032000  r1 : 00000028  r0 : 00000001

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
[tony@atomide.com: updated comments]
Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-01-26 15:27:32 -08:00

491 lines
13 KiB
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 <asm/mach/time.h>
#include <plat/dmtimer.h>
#include <asm/localtimer.h>
#include <asm/sched_clock.h>
#include "common.h"
#include <plat/omap_hwmod.h>
#include <plat/omap_device.h>
#include <plat/omap-pm.h>
#include "powerdomain.h"
/* Parent clocks, eventually these will come from the clock framework */
#define OMAP2_MPU_SOURCE "sys_ck"
#define OMAP3_MPU_SOURCE OMAP2_MPU_SOURCE
#define OMAP4_MPU_SOURCE "sys_clkin_ck"
#define OMAP2_32K_SOURCE "func_32k_ck"
#define OMAP3_32K_SOURCE "omap_32k_fck"
#define OMAP4_32K_SOURCE "sys_32k_ck"
#ifdef CONFIG_OMAP_32K_TIMER
#define OMAP2_CLKEV_SOURCE OMAP2_32K_SOURCE
#define OMAP3_CLKEV_SOURCE OMAP3_32K_SOURCE
#define OMAP4_CLKEV_SOURCE OMAP4_32K_SOURCE
#define OMAP3_SECURE_TIMER 12
#else
#define OMAP2_CLKEV_SOURCE OMAP2_MPU_SOURCE
#define OMAP3_CLKEV_SOURCE OMAP3_MPU_SOURCE
#define OMAP4_CLKEV_SOURCE OMAP4_MPU_SOURCE
#define OMAP3_SECURE_TIMER 1
#endif
/* MAX_GPTIMER_ID: number of GPTIMERs on the chip */
#define MAX_GPTIMER_ID 12
static u32 sys_timer_reserved;
/* Clockevent code */
static struct omap_dm_timer clkev;
static struct clock_event_device clockevent_gpt;
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_DISABLED | 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, 1);
return 0;
}
static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
u32 period;
__omap_dm_timer_stop(&clkev, 1, clkev.rate);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
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, 1);
__omap_dm_timer_load_start(&clkev,
OMAP_TIMER_CTRL_AR | OMAP_TIMER_CTRL_ST,
0xffffffff - period, 1);
break;
case CLOCK_EVT_MODE_ONESHOT:
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_RESUME:
break;
}
}
static struct clock_event_device clockevent_gpt = {
.name = "gp timer",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.set_next_event = omap2_gp_timer_set_next_event,
.set_mode = omap2_gp_timer_set_mode,
};
static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
int gptimer_id,
const char *fck_source)
{
char name[10]; /* 10 = sizeof("gptXX_Xck0") */
struct omap_hwmod *oh;
size_t size;
int res = 0;
sprintf(name, "timer%d", gptimer_id);
omap_hwmod_setup_one(name);
oh = omap_hwmod_lookup(name);
if (!oh)
return -ENODEV;
timer->irq = oh->mpu_irqs[0].irq;
timer->phys_base = oh->slaves[0]->addr->pa_start;
size = oh->slaves[0]->addr->pa_end - timer->phys_base;
/* Static mapping, never released */
timer->io_base = ioremap(timer->phys_base, size);
if (!timer->io_base)
return -ENXIO;
/* After the dmtimer is using hwmod these clocks won't be needed */
sprintf(name, "gpt%d_fck", gptimer_id);
timer->fclk = clk_get(NULL, name);
if (IS_ERR(timer->fclk))
return -ENODEV;
sprintf(name, "gpt%d_ick", gptimer_id);
timer->iclk = clk_get(NULL, name);
if (IS_ERR(timer->iclk)) {
clk_put(timer->fclk);
return -ENODEV;
}
omap_hwmod_enable(oh);
sys_timer_reserved |= (1 << (gptimer_id - 1));
if (gptimer_id != 12) {
struct clk *src;
src = clk_get(NULL, fck_source);
if (IS_ERR(src)) {
res = -EINVAL;
} else {
res = __omap_dm_timer_set_source(timer->fclk, src);
if (IS_ERR_VALUE(res))
pr_warning("%s: timer%i cannot set source\n",
__func__, gptimer_id);
clk_put(src);
}
}
__omap_dm_timer_init_regs(timer);
__omap_dm_timer_reset(timer, 1, 1);
timer->posted = 1;
timer->rate = clk_get_rate(timer->fclk);
timer->reserved = 1;
return res;
}
static void __init omap2_gp_clockevent_init(int gptimer_id,
const char *fck_source)
{
int res;
res = omap_dm_timer_init_one(&clkev, gptimer_id, fck_source);
BUG_ON(res);
omap2_gp_timer_irq.dev_id = (void *)&clkev;
setup_irq(clkev.irq, &omap2_gp_timer_irq);
__omap_dm_timer_int_enable(&clkev, OMAP_TIMER_INT_OVERFLOW);
clockevent_gpt.mult = div_sc(clkev.rate, NSEC_PER_SEC,
clockevent_gpt.shift);
clockevent_gpt.max_delta_ns =
clockevent_delta2ns(0xffffffff, &clockevent_gpt);
clockevent_gpt.min_delta_ns =
clockevent_delta2ns(3, &clockevent_gpt);
/* Timer internal resynch latency. */
clockevent_gpt.cpumask = cpumask_of(0);
clockevents_register_device(&clockevent_gpt);
pr_info("OMAP clockevent source: GPTIMER%d at %lu Hz\n",
gptimer_id, clkev.rate);
}
/* Clocksource code */
#ifdef CONFIG_OMAP_32K_TIMER
/*
* When 32k-timer is enabled, don't use GPTimer for clocksource
* instead, just leave default clocksource which uses the 32k
* sync counter. See clocksource setup in plat-omap/counter_32k.c
*/
static void __init omap2_gp_clocksource_init(int unused, const char *dummy)
{
omap_init_clocksource_32k();
}
#else
static struct omap_dm_timer clksrc;
/*
* clocksource
*/
static cycle_t clocksource_read_cycles(struct clocksource *cs)
{
return (cycle_t)__omap_dm_timer_read_counter(&clksrc, 1);
}
static struct clocksource clocksource_gpt = {
.name = "gp timer",
.rating = 300,
.read = clocksource_read_cycles,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static u32 notrace dmtimer_read_sched_clock(void)
{
if (clksrc.reserved)
return __omap_dm_timer_read_counter(&clksrc, 1);
return 0;
}
/* Setup free-running counter for clocksource */
static void __init omap2_gp_clocksource_init(int gptimer_id,
const char *fck_source)
{
int res;
res = omap_dm_timer_init_one(&clksrc, gptimer_id, fck_source);
BUG_ON(res);
pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
gptimer_id, clksrc.rate);
__omap_dm_timer_load_start(&clksrc,
OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1);
setup_sched_clock(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);
}
#endif
#define OMAP_SYS_TIMER_INIT(name, clkev_nr, clkev_src, \
clksrc_nr, clksrc_src) \
static void __init omap##name##_timer_init(void) \
{ \
omap2_gp_clockevent_init((clkev_nr), clkev_src); \
omap2_gp_clocksource_init((clksrc_nr), clksrc_src); \
}
#define OMAP_SYS_TIMER(name) \
struct sys_timer omap##name##_timer = { \
.init = omap##name##_timer_init, \
};
#ifdef CONFIG_ARCH_OMAP2
OMAP_SYS_TIMER_INIT(2, 1, OMAP2_CLKEV_SOURCE, 2, OMAP2_MPU_SOURCE)
OMAP_SYS_TIMER(2)
#endif
#ifdef CONFIG_ARCH_OMAP3
OMAP_SYS_TIMER_INIT(3, 1, OMAP3_CLKEV_SOURCE, 2, OMAP3_MPU_SOURCE)
OMAP_SYS_TIMER(3)
OMAP_SYS_TIMER_INIT(3_secure, OMAP3_SECURE_TIMER, OMAP3_CLKEV_SOURCE,
2, OMAP3_MPU_SOURCE)
OMAP_SYS_TIMER(3_secure)
#endif
#ifdef CONFIG_ARCH_OMAP4
static void __init omap4_timer_init(void)
{
#ifdef CONFIG_LOCAL_TIMERS
twd_base = ioremap(OMAP44XX_LOCAL_TWD_BASE, SZ_256);
BUG_ON(!twd_base);
#endif
omap2_gp_clockevent_init(1, OMAP4_CLKEV_SOURCE);
omap2_gp_clocksource_init(2, OMAP4_MPU_SOURCE);
}
OMAP_SYS_TIMER(4)
#endif
/**
* omap2_dm_timer_set_src - change the timer input clock source
* @pdev: timer platform device pointer
* @source: array index of parent clock source
*/
static int omap2_dm_timer_set_src(struct platform_device *pdev, int source)
{
int ret;
struct dmtimer_platform_data *pdata = pdev->dev.platform_data;
struct clk *fclk, *parent;
char *parent_name = NULL;
fclk = clk_get(&pdev->dev, "fck");
if (IS_ERR_OR_NULL(fclk)) {
dev_err(&pdev->dev, "%s: %d: clk_get() FAILED\n",
__func__, __LINE__);
return -EINVAL;
}
switch (source) {
case OMAP_TIMER_SRC_SYS_CLK:
parent_name = "sys_ck";
break;
case OMAP_TIMER_SRC_32_KHZ:
parent_name = "32k_ck";
break;
case OMAP_TIMER_SRC_EXT_CLK:
if (pdata->timer_ip_version == OMAP_TIMER_IP_VERSION_1) {
parent_name = "alt_ck";
break;
}
dev_err(&pdev->dev, "%s: %d: invalid clk src.\n",
__func__, __LINE__);
clk_put(fclk);
return -EINVAL;
}
parent = clk_get(&pdev->dev, parent_name);
if (IS_ERR_OR_NULL(parent)) {
dev_err(&pdev->dev, "%s: %d: clk_get() %s FAILED\n",
__func__, __LINE__, parent_name);
clk_put(fclk);
return -EINVAL;
}
ret = clk_set_parent(fclk, parent);
if (IS_ERR_VALUE(ret)) {
dev_err(&pdev->dev, "%s: clk_set_parent() to %s FAILED\n",
__func__, parent_name);
ret = -EINVAL;
}
clk_put(parent);
clk_put(fclk);
return ret;
}
/**
* 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;
struct powerdomain *pwrdm;
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);
pdata->set_timer_src = omap2_dm_timer_set_src;
pdata->timer_ip_version = oh->class->rev;
/* Mark clocksource and clockevent timers as reserved */
if ((sys_timer_reserved >> (id - 1)) & 0x1)
pdata->reserved = 1;
pwrdm = omap_hwmod_get_pwrdm(oh);
pdata->loses_context = pwrdm_can_ever_lose_context(pwrdm);
#ifdef CONFIG_PM
pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
#endif
pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata),
NULL, 0, 0);
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;
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;
}
arch_initcall(omap2_dm_timer_init);