On 04/10/2012 11:21 AM, Roberto Bielli wrote:
> Hi Gilles,
>
> here is my time.c
Though you have not made all the changes I suggested. Here is the time.c
I would use.
--
Gilles.
/*
* linux/arch/arm/plat-mxc/time.c
*
* Copyright (C) 2000-2001 Deep Blue Solutions
* Copyright (C) 2002 Shane Nay ([email protected])
* Copyright (C) 2006-2007 Pavel Pisa ([email protected])
* Copyright (C) 2008 Juergen Beisert ([email protected])
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/clockchips.h>
#include <linux/clk.h>
#include <mach/hardware.h>
#include <asm/mach/time.h>
#include <mach/common.h>
/* defines common for all i.MX */
#define MXC_TCTL 0x00
#define MXC_TCTL_TEN (1 << 0)
#define MXC_TPRER 0x04
/* MX1, MX21, MX27 */
#define MX1_2_TCTL_CLK_PCLK1 (1 << 1)
#define MX1_2_TCTL_IRQEN (1 << 4)
#define MX1_2_TCTL_FRR (1 << 8)
#define MX1_2_TCMP 0x08
#define MX1_2_TCN 0x10
#define MX1_2_TSTAT 0x14
/* MX21, MX27 */
#define MX2_TSTAT_CAPT (1 << 1)
#define MX2_TSTAT_COMP (1 << 0)
/* MX31, MX35, MX25 */
#define MX3_TCTL_WAITEN (1 << 3)
#define MX3_TCTL_CLK_IPG (1 << 6)
#define MX3_TCTL_CLK_PER (2 << 6)
#define MX3_TCTL_FRR (1 << 9)
#define MX3_IR 0x0c
#define MX3_TSTAT 0x08
#define MX3_TSTAT_OF1 (1 << 0)
#define MX3_TCN 0x24
#define MX3_TCMP 0x10
#ifdef CONFIG_IPIPE
#ifdef CONFIG_NO_IDLE_HZ
#error "dynamic tick timer not yet supported with IPIPE"
#endif /* CONFIG_NO_IDLE_HZ */
int __ipipe_mach_timerint;
EXPORT_SYMBOL(__ipipe_mach_timerint);
int __ipipe_mach_timerstolen = 0;
EXPORT_SYMBOL(__ipipe_mach_timerstolen);
unsigned int __ipipe_mach_ticks_per_jiffy = LATCH;
EXPORT_SYMBOL(__ipipe_mach_ticks_per_jiffy);
static int mxc_timer_initialized;
static unsigned mxc_min_delay;
union tsc_reg {
#ifdef __BIG_ENDIAN
struct {
unsigned long high;
unsigned long low;
};
#else /* __LITTLE_ENDIAN */
struct {
unsigned long low;
unsigned long high;
};
#endif /* __LITTLE_ENDIAN */
unsigned long long full;
};
#ifdef CONFIG_SMP
static union tsc_reg tsc[NR_CPUS];
void __ipipe_mach_get_tscinfo(struct __ipipe_tscinfo *info)
{
info->type = IPIPE_TSC_TYPE_NONE;
}
#else /* !CONFIG_SMP */
static union tsc_reg *tsc;
void __ipipe_mach_get_tscinfo(struct __ipipe_tscinfo *info)
{
info->type = IPIPE_TSC_TYPE_FREERUNNING;
if (cpu_is_mx1()) {
#ifdef CONFIG_ARCH_MX1
info->u.fr.counter = (unsigned *) (TIM1_BASE_ADDR + MX1_2_TCN);
#endif
} else if (cpu_is_mx2()) {
#ifdef CONFIG_ARCH_MX2
info->u.fr.counter = (unsigned *) (GPT1_BASE_ADDR + MX1_2_TCN);
#endif
} else if (cpu_is_mx3() || cpu_is_mx25() ) {
#if defined CONFIG_ARCH_MX3 || defined CONFIG_ARCH_MX25
info->u.fr.counter = (unsigned *) (GPT1_BASE_ADDR + MX3_TCN);
#endif
}
info->u.fr.mask = 0xffffffff;
info->u.fr.tsc = &tsc->full;
}
#endif /* !CONFIG_SMP */
static void ipipe_mach_update_tsc(void);
#endif /* CONFIG_IPIPE */
#define timer_is_v2() (cpu_is_mx3() || cpu_is_mx25() || cpu_is_mx5())
static struct clock_event_device clockevent_mxc;
static enum clock_event_mode clockevent_mode = CLOCK_EVT_MODE_UNUSED;
static void __iomem *timer_base;
static inline void gpt_irq_disable(void)
{
unsigned int tmp;
if (timer_is_v2())
__raw_writel(0, timer_base + MX3_IR);
else {
tmp = __raw_readl(timer_base + MXC_TCTL);
__raw_writel(tmp & ~MX1_2_TCTL_IRQEN, timer_base + MXC_TCTL);
}
}
static inline void gpt_irq_enable(void)
{
if (timer_is_v2())
__raw_writel(1<<0, timer_base + MX3_IR);
else {
__raw_writel(__raw_readl(timer_base + MXC_TCTL) | MX1_2_TCTL_IRQEN,
timer_base + MXC_TCTL);
}
}
static void gpt_irq_acknowledge(void)
{
if (!timer_is_v2()) {
if (cpu_is_mx1())
__raw_writel(0, timer_base + MX1_2_TSTAT);
else
__raw_writel(MX2_TSTAT_CAPT | MX2_TSTAT_COMP, timer_base + MX1_2_TSTAT);
} else
__raw_writel(MX3_TSTAT_OF1, timer_base + MX3_TSTAT);
}
static cycle_t timer_v1_get_cycles(struct clocksource *cs)
{
return __raw_readl(timer_base + MX1_2_TCN);
}
static cycle_t timer_v2_get_cycles(struct clocksource *cs)
{
return __raw_readl(timer_base + MX3_TCN);
}
static struct clocksource clocksource_mxc = {
.name = "mxc_timer1",
.rating = 200,
.read = timer_v1_get_cycles,
.mask = CLOCKSOURCE_MASK(32),
.shift = 20,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static int __init mxc_clocksource_init(struct clk *timer_clk)
{
unsigned int c = clk_get_rate(timer_clk);
if (timer_is_v2())
clocksource_mxc.read = timer_v2_get_cycles;
#ifdef CONFIG_IPIPE
__ipipe_mach_ticks_per_jiffy = (c + HZ/2) / HZ;
#endif /* CONFIG_IPIPE */
clocksource_mxc.mult = clocksource_hz2mult(c,
clocksource_mxc.shift);
clocksource_register(&clocksource_mxc);
return 0;
}
/* clock event */
static int timer_v1_set_next_event(unsigned long evt,
struct clock_event_device *unused)
{
unsigned long tcmp;
tcmp = __raw_readl(timer_base + MX1_2_TCN) + evt;
__raw_writel(tcmp, timer_base + MX1_2_TCMP);
return (int)(tcmp - __raw_readl(timer_base + MX1_2_TCN)) < 0 ?
-ETIME : 0;
}
static int timer_v2_set_next_event(unsigned long evt,
struct clock_event_device *unused)
{
unsigned long tcmp;
tcmp = __raw_readl(timer_base + MX3_TCN) + evt;
__raw_writel(tcmp, timer_base + MX3_TCMP);
return (int)(tcmp - __raw_readl(timer_base + MX3_TCN)) < 0 ? -ETIME : 0;
}
#ifdef DEBUG
static inline const char *clock_event_mode_label(enum clock_event_mode mode)
{
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
return "CLOCK_EVT_MODE_PERIODIC";
case CLOCK_EVT_MODE_ONESHOT:
return "CLOCK_EVT_MODE_ONESHOT";
case CLOCK_EVT_MODE_SHUTDOWN:
return "CLOCK_EVT_MODE_SHUTDOWN";
case CLOCK_EVT_MODE_UNUSED:
return "CLOCK_EVT_MODE_UNUSED";
case CLOCK_EVT_MODE_RESUME:
return "CLOCK_EVT_MODE_RESUME";
}
return "UNKNOWN";
};
#endif /* DEBUG */
static void mxc_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
unsigned long flags;
/*
* The timer interrupt generation is disabled at least
* for enough time to call mxc_set_next_event()
*/
local_irq_save(flags);
/* Disable interrupt in GPT module */
gpt_irq_disable();
if (mode != clockevent_mode) {
/* Set event time into far-far future */
if (timer_is_v2())
__raw_writel(__raw_readl(timer_base + MX3_TCN) - 3,
timer_base + MX3_TCMP);
else
__raw_writel(__raw_readl(timer_base + MX1_2_TCN) - 3,
timer_base + MX1_2_TCMP);
/* Clear pending interrupt */
gpt_irq_acknowledge();
}
#ifdef DEBUG
printk(KERN_INFO "mxc_set_mode: changing mode from %s[%d] to %s[%d]\n",
clock_event_mode_label(clockevent_mode), clockevent_mode,
clock_event_mode_label(mode), mode);
#endif /* DEBUG */
/* Remember timer mode */
clockevent_mode = mode;
local_irq_restore(flags);
switch (mode)
{
case CLOCK_EVT_MODE_PERIODIC:
printk(KERN_ERR "mxc_set_mode: Periodic mode is not supported for i.MX\n");
break;
case CLOCK_EVT_MODE_ONESHOT:
/*
* Do not put overhead of interrupt enable/disable into
* mxc_set_next_event(), the core has about 4 minutes
* to call mxc_set_next_event() or shutdown clock after
* mode switching
*/
local_irq_save(flags);
gpt_irq_enable();
local_irq_restore(flags);
break;
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_RESUME:
/* Left event sources disabled, no more interrupts appear */
break;
}
}
/*
* IRQ handler for the timer
*/
static irqreturn_t mxc_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = &clockevent_mxc;
uint32_t tstat;
unsigned long reg;
#ifndef CONFIG_IPIPE
if (timer_is_v2())
tstat = __raw_readl(timer_base + MX3_TSTAT);
else
tstat = __raw_readl(timer_base + MX1_2_TSTAT);
gpt_irq_acknowledge();
#else /* !CONFIG_IPIPE */
ipipe_mach_update_tsc();
#endif /* !CONFIG_IPIPE */
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction mxc_timer_irq = {
.name = "i.MX Timer Tick",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = mxc_timer_interrupt,
};
static struct clock_event_device clockevent_mxc = {
.name = "mxc_timer1",
.features = CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.set_mode = mxc_set_mode,
.set_next_event = timer_v1_set_next_event,
.rating = 200,
};
static int __init mxc_clockevent_init(struct clk *timer_clk)
{
unsigned long c = clk_get_rate(timer_clk);
printk(KERN_DEBUG "%s: timer clk rate is %lu.%03luMHz\n", __FUNCTION__,
c / 1000000, c / 1000 % 1000);
if (timer_is_v2())
clockevent_mxc.set_next_event = timer_v2_set_next_event;
clockevent_mxc.mult = div_sc(c, NSEC_PER_SEC,
clockevent_mxc.shift);
clockevent_mxc.max_delta_ns =
clockevent_delta2ns(0xfffffffe, &clockevent_mxc);
clockevent_mxc.min_delta_ns =
clockevent_delta2ns(0xff, &clockevent_mxc);
clockevent_mxc.cpumask = cpumask_of(0);
clockevents_register_device(&clockevent_mxc);
return 0;
}
void __init mxc_timer_init(struct clk *timer_clk, void __iomem *base, int irq)
{
uint32_t tctl_val;
clk_enable(timer_clk);
timer_base = base;
/*
* Initialise to a known state (all timers off, and timing reset)
*/
__raw_writel(0, timer_base + MXC_TCTL);
__raw_writel(0, timer_base + MXC_TPRER); /* see datasheet note */
if (timer_is_v2())
tctl_val = MX3_TCTL_CLK_IPG | MX3_TCTL_FRR | MX3_TCTL_WAITEN | MXC_TCTL_TEN;
else
tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN;
__raw_writel(tctl_val, timer_base + MXC_TCTL);
/* init and register the timer to the framework */
mxc_clocksource_init(timer_clk);
mxc_clockevent_init(timer_clk);
/* Make irqs happen */
setup_irq(irq, &mxc_timer_irq);
#ifdef CONFIG_IPIPE
__ipipe_mach_timerint = irq;
#ifndef CONFIG_SMP
tsc = (union tsc_reg *) __ipipe_tsc_area;
barrier();
#endif /* CONFIG_SMP */
mxc_min_delay = 2 * ((ipipe_cpu_freq() + 500000) / 1000000) ?: 1;
if (mxc_min_delay == 0)
{
mxc_min_delay = 1;
}
printk( KERN_INFO "mxc_min_delay = %d\n", mxc_min_delay );
mxc_timer_initialized = 1;
#endif /* CONFIG_IPIPE */
}
#ifdef CONFIG_IPIPE
int __ipipe_check_tickdev(const char *devname)
{
return !strcmp(devname, clockevent_mxc.name);
}
void __ipipe_mach_acktimer(void)
{
uint32_t tstat;
if (timer_is_v2())
tstat = __raw_readl(timer_base + MX3_TSTAT);
else
tstat = __raw_readl(timer_base + MX1_2_TSTAT);
gpt_irq_acknowledge();
}
static void ipipe_mach_update_tsc(void)
{
union tsc_reg *local_tsc;
unsigned long stamp, flags;
local_irq_save_hw(flags);
local_tsc = &tsc[ipipe_processor_id()];
if (!timer_is_v2())
stamp = __raw_readl(timer_base + MX1_2_TCN);
else
stamp = __raw_readl(timer_base + MX3_TCN);
if (unlikely(stamp < local_tsc->low))
/* 32 bit counter wrapped, increment high word. */
local_tsc->high++;
local_tsc->low = stamp;
local_irq_restore_hw(flags);
}
notrace unsigned long long __ipipe_mach_get_tsc(void)
{
if (likely(mxc_timer_initialized)) {
union tsc_reg *local_tsc, result;
unsigned long stamp;
local_tsc = &tsc[ipipe_processor_id()];
if (!timer_is_v2()) {
__asm__ ("ldmia %1, %M0\n"
: "=r"(result.full), "+&r"(local_tsc)
: "m"(*local_tsc));
barrier();
stamp = __raw_readl(timer_base + MX1_2_TCN);
} else {
__asm__ ("ldmia %1, %M0\n"
: "=r"(result.full), "+&r"(local_tsc)
: "m"(*local_tsc));
barrier();
stamp = __raw_readl(timer_base + MX3_TCN);
}
if (unlikely(stamp < result.low))
/* 32 bit counter wrapped, increment high word. */
result.high++;
result.low = stamp;
return result.full;
}
return 0;
}
EXPORT_SYMBOL(__ipipe_mach_get_tsc);
/*
* Reprogram the timer
*/
void __ipipe_mach_set_dec(unsigned long delay)
{
if (delay > mxc_min_delay) {
unsigned long flags;
local_irq_save_hw(flags);
if (!time_is_v2())
timer_v1_set_next_event(delay, NULL);
else
timer_v2_set_next_event(delay, NULL);
local_irq_restore_hw(flags);
} else
ipipe_trigger_irq(__ipipe_mach_timerint);
}
EXPORT_SYMBOL(__ipipe_mach_set_dec);
void __ipipe_mach_release_timer(void)
{
mxc_set_mode(clockevent_mxc.mode, &clockevent_mxc);
if (clockevent_mxc.mode == CLOCK_EVT_MODE_ONESHOT)
clockevent_mxc.set_next_event(LATCH, &clockevent_mxc);
}
EXPORT_SYMBOL(__ipipe_mach_release_timer);
unsigned long __ipipe_mach_get_dec(void)
{
if (!time_is_v2())
return __raw_readl(timer_base + MX1_2_TCMP)
- __raw_readl(timer_base + MX1_2_TCN);
else
return __raw_readl(timer_base + MX3_TCMP)
- __raw_readl(timer_base + MX3_TCN);
}
#endif /* CONFIG_IPIPE */
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