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This cleans up the ks8695 timer driver and converts

it to use generic time and clock events.
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Merge tag 'ks8695-time-for-arm-soc' of http://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson into next/cleanup

This cleans up the ks8695 timer driver and converts
it to use generic time and clock events.

* tag 'ks8695-time-for-arm-soc' of http://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson:
  ARM: ks8695: convert to generic time and clocksource
  ARM: ks8695: delete resume hook from timer
  ARM: ks8695: use [readl|writel]_relaxed()
  ARM: ks8695: merge the timer header into the timer driver
hifive-unleashed-5.1
Olof Johansson 2012-09-05 10:39:09 -07:00
commit ae2fe0c0ca
3 changed files with 89 additions and 81 deletions

View File

@ -641,8 +641,9 @@ config ARCH_KS8695
bool "Micrel/Kendin KS8695"
select CPU_ARM922T
select ARCH_REQUIRE_GPIOLIB
select ARCH_USES_GETTIMEOFFSET
select NEED_MACH_MEMORY_H
select CLKSRC_MMIO
select GENERIC_CLOCKEVENTS
help
Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
System-on-Chip devices.

View File

@ -1,40 +0,0 @@
/*
* arch/arm/mach-ks8695/include/mach/regs-timer.h
*
* Copyright (C) 2006 Ben Dooks <ben@simtec.co.uk>
* Copyright (C) 2006 Simtec Electronics
*
* KS8695 - Timer registers and bit definitions.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#ifndef KS8695_TIMER_H
#define KS8695_TIMER_H
#define KS8695_TMR_OFFSET (0xF0000 + 0xE400)
#define KS8695_TMR_VA (KS8695_IO_VA + KS8695_TMR_OFFSET)
#define KS8695_TMR_PA (KS8695_IO_PA + KS8695_TMR_OFFSET)
/*
* Timer registers
*/
#define KS8695_TMCON (0x00) /* Timer Control Register */
#define KS8695_T1TC (0x04) /* Timer 1 Timeout Count Register */
#define KS8695_T0TC (0x08) /* Timer 0 Timeout Count Register */
#define KS8695_T1PD (0x0C) /* Timer 1 Pulse Count Register */
#define KS8695_T0PD (0x10) /* Timer 0 Pulse Count Register */
/* Timer Control Register */
#define TMCON_T1EN (1 << 1) /* Timer 1 Enable */
#define TMCON_T0EN (1 << 0) /* Timer 0 Enable */
/* Timer0 Timeout Counter Register */
#define T0TC_WATCHDOG (0xff) /* Enable watchdog mode */
#endif

View File

@ -25,53 +25,98 @@
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/io.h>
#include <linux/clockchips.h>
#include <asm/mach/time.h>
#include <asm/system_misc.h>
#include <mach/regs-timer.h>
#include <mach/regs-irq.h>
#include "generic.h"
#define KS8695_TMR_OFFSET (0xF0000 + 0xE400)
#define KS8695_TMR_VA (KS8695_IO_VA + KS8695_TMR_OFFSET)
#define KS8695_TMR_PA (KS8695_IO_PA + KS8695_TMR_OFFSET)
/*
* Returns number of ms since last clock interrupt. Note that interrupts
* will have been disabled by do_gettimeoffset()
* Timer registers
*/
static unsigned long ks8695_gettimeoffset (void)
#define KS8695_TMCON (0x00) /* Timer Control Register */
#define KS8695_T1TC (0x04) /* Timer 1 Timeout Count Register */
#define KS8695_T0TC (0x08) /* Timer 0 Timeout Count Register */
#define KS8695_T1PD (0x0C) /* Timer 1 Pulse Count Register */
#define KS8695_T0PD (0x10) /* Timer 0 Pulse Count Register */
/* Timer Control Register */
#define TMCON_T1EN (1 << 1) /* Timer 1 Enable */
#define TMCON_T0EN (1 << 0) /* Timer 0 Enable */
/* Timer0 Timeout Counter Register */
#define T0TC_WATCHDOG (0xff) /* Enable watchdog mode */
static void ks8695_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
unsigned long elapsed, tick2, intpending;
u32 tmcon;
/*
* Get the current number of ticks. Note that there is a race
* condition between us reading the timer and checking for an
* interrupt. We solve this by ensuring that the counter has not
* reloaded between our two reads.
*/
elapsed = __raw_readl(KS8695_TMR_VA + KS8695_T1TC) + __raw_readl(KS8695_TMR_VA + KS8695_T1PD);
do {
tick2 = elapsed;
intpending = __raw_readl(KS8695_IRQ_VA + KS8695_INTST) & (1 << KS8695_IRQ_TIMER1);
elapsed = __raw_readl(KS8695_TMR_VA + KS8695_T1TC) + __raw_readl(KS8695_TMR_VA + KS8695_T1PD);
} while (elapsed > tick2);
if (mode == CLOCK_EVT_FEAT_PERIODIC) {
u32 rate = DIV_ROUND_CLOSEST(KS8695_CLOCK_RATE, HZ);
u32 half = DIV_ROUND_CLOSEST(rate, 2);
/* Convert to number of ticks expired (not remaining) */
elapsed = (CLOCK_TICK_RATE / HZ) - elapsed;
/* Disable timer 1 */
tmcon = readl_relaxed(KS8695_TMR_VA + KS8695_TMCON);
tmcon &= ~TMCON_T1EN;
writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON);
/* Is interrupt pending? If so, then timer has been reloaded already. */
if (intpending)
elapsed += (CLOCK_TICK_RATE / HZ);
/* Both registers need to count down */
writel_relaxed(half, KS8695_TMR_VA + KS8695_T1TC);
writel_relaxed(half, KS8695_TMR_VA + KS8695_T1PD);
/* Convert ticks to usecs */
return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH;
/* Re-enable timer1 */
tmcon |= TMCON_T1EN;
writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON);
}
}
static int ks8695_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
u32 half = DIV_ROUND_CLOSEST(cycles, 2);
u32 tmcon;
/* Disable timer 1 */
tmcon = readl_relaxed(KS8695_TMR_VA + KS8695_TMCON);
tmcon &= ~TMCON_T1EN;
writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON);
/* Both registers need to count down */
writel_relaxed(half, KS8695_TMR_VA + KS8695_T1TC);
writel_relaxed(half, KS8695_TMR_VA + KS8695_T1PD);
/* Re-enable timer1 */
tmcon |= TMCON_T1EN;
writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON);
return 0;
}
static struct clock_event_device clockevent_ks8695 = {
.name = "ks8695_t1tc",
.rating = 300, /* Reasonably fast and accurate clock event */
.features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
.set_next_event = ks8695_set_next_event,
.set_mode = ks8695_set_mode,
};
/*
* IRQ handler for the timer.
*/
static irqreturn_t ks8695_timer_interrupt(int irq, void *dev_id)
{
timer_tick();
struct clock_event_device *evt = &clockevent_ks8695;
evt->event_handler(evt);
return IRQ_HANDLED;
}
@ -83,18 +128,22 @@ static struct irqaction ks8695_timer_irq = {
static void ks8695_timer_setup(void)
{
unsigned long tmout = CLOCK_TICK_RATE / HZ;
unsigned long tmcon;
/* disable timer1 */
tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
__raw_writel(tmcon & ~TMCON_T1EN, KS8695_TMR_VA + KS8695_TMCON);
/* Disable timer 0 and 1 */
tmcon = readl_relaxed(KS8695_TMR_VA + KS8695_TMCON);
tmcon &= ~TMCON_T0EN;
tmcon &= ~TMCON_T1EN;
writel_relaxed(tmcon, KS8695_TMR_VA + KS8695_TMCON);
__raw_writel(tmout / 2, KS8695_TMR_VA + KS8695_T1TC);
__raw_writel(tmout / 2, KS8695_TMR_VA + KS8695_T1PD);
/* re-enable timer1 */
__raw_writel(tmcon | TMCON_T1EN, KS8695_TMR_VA + KS8695_TMCON);
/*
* Use timer 1 to fire IRQs on the timeline, minimum 2 cycles
* (one on each counter) maximum 2*2^32, but the API will only
* accept up to a 32bit full word (0xFFFFFFFFU).
*/
clockevents_config_and_register(&clockevent_ks8695,
KS8695_CLOCK_RATE, 2,
0xFFFFFFFFU);
}
static void __init ks8695_timer_init (void)
@ -107,8 +156,6 @@ static void __init ks8695_timer_init (void)
struct sys_timer ks8695_timer = {
.init = ks8695_timer_init,
.offset = ks8695_gettimeoffset,
.resume = ks8695_timer_setup,
};
void ks8695_restart(char mode, const char *cmd)
@ -119,12 +166,12 @@ void ks8695_restart(char mode, const char *cmd)
soft_restart(0);
/* disable timer0 */
reg = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
__raw_writel(reg & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
reg = readl_relaxed(KS8695_TMR_VA + KS8695_TMCON);
writel_relaxed(reg & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
/* enable watchdog mode */
__raw_writel((10 << 8) | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC);
writel_relaxed((10 << 8) | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC);
/* re-enable timer0 */
__raw_writel(reg | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
writel_relaxed(reg | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
}