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Commit cfca3a61 authored by Changhwan Youn's avatar Changhwan Youn Committed by Kukjin Kim
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ARM: S5PV310: Add Timer support 



This patch adds timer support for S5PV310.  Until now, all S5P SoCs
use CONFIG_ARCH_USES_GETTIMEOFFSET macro as a default configuration.
Instead,S5PV310 implements clocksource and clock_event_device to
support the high resolution timer and tickless system.

Signed-off-by: default avatarChanghwan Youn <chaos.youn@samsung.com>
Signed-off-by: default avatarHyuk Lee <hyuk1.lee@samsung.com>
Signed-off-by: default avatarKukjin Kim <kgene.kim@samsung.com>
parent 84bbc16c

arch/arm/mach-s5pv310/include/mach/pwm-clock.h

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/* linux/arch/arm/mach-s5pv310/include/mach/pwm-clock.h

 *

 * Copyright (c) 2010 Samsung Electronics Co., Ltd.

 *		http://www.samsung.com/

 *

 * Copyright 2008 Openmoko, Inc.

 * Copyright 2008 Simtec Electronics

 *      Ben Dooks <ben@simtec.co.uk>

 *      http://armlinux.simtec.co.uk/

 *

 * Based on arch/arm/mach-s3c64xx/include/mach/pwm-clock.h

 *

 * S5PV310 - pwm clock and timer support

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

*/



#ifndef __ASM_ARCH_PWMCLK_H

#define __ASM_ARCH_PWMCLK_H __FILE__



/**

 * pwm_cfg_src_is_tclk() - return whether the given mux config is a tclk

 * @tcfg: The timer TCFG1 register bits shifted down to 0.

 *

 * Return true if the given configuration from TCFG1 is a TCLK instead

 * any of the TDIV clocks.

 */

static inline int pwm_cfg_src_is_tclk(unsigned long tcfg)

{

	return tcfg == S3C64XX_TCFG1_MUX_TCLK;

}



/**

 * tcfg_to_divisor() - convert tcfg1 setting to a divisor

 * @tcfg1: The tcfg1 setting, shifted down.

 *

 * Get the divisor value for the given tcfg1 setting. We assume the

 * caller has already checked to see if this is not a TCLK source.

 */

static inline unsigned long tcfg_to_divisor(unsigned long tcfg1)

{

	return 1 << tcfg1;

}



/**

 * pwm_tdiv_has_div1() - does the tdiv setting have a /1

 *

 * Return true if we have a /1 in the tdiv setting.

 */

static inline unsigned int pwm_tdiv_has_div1(void)

{

	return 1;

}



/**

 * pwm_tdiv_div_bits() - calculate TCFG1 divisor value.

 * @div: The divisor to calculate the bit information for.

 *

 * Turn a divisor into the necessary bit field for TCFG1.

 */

static inline unsigned long pwm_tdiv_div_bits(unsigned int div)

{

	return ilog2(div);

}



#define S3C_TCFG1_MUX_TCLK S3C64XX_TCFG1_MUX_TCLK



#endif /* __ASM_ARCH_PWMCLK_H */

arch/arm/mach-s5pv310/localtimer.c

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/* linux/arch/arm/mach-s5pv310/localtimer.c

 *

 * Cloned from linux/arch/arm/mach-realview/localtimer.c

 *

 *  Copyright (C) 2002 ARM Ltd.

 *  All Rights Reserved

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

*/



#include <linux/clockchips.h>



#include <asm/irq.h>

#include <asm/localtimer.h>



/*

 * Setup the local clock events for a CPU.

 */

void __cpuinit local_timer_setup(struct clock_event_device *evt)

{

	evt->irq = IRQ_LOCALTIMER;

	twd_timer_setup(evt);

}

arch/arm/mach-s5pv310/time.c

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Original line number Diff line number Diff line 
/* linux/arch/arm/mach-s5pv310/time.c

 *

 * Copyright (c) 2010 Samsung Electronics Co., Ltd.

 *		http://www.samsung.com

 *

 * S5PV310 (and compatible) HRT support

 * PWM 2/4 is used for this feature

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

*/



#include <linux/sched.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/err.h>

#include <linux/clk.h>

#include <linux/clockchips.h>

#include <linux/platform_device.h>



#include <asm/smp_twd.h>



#include <mach/map.h>

#include <plat/regs-timer.h>

#include <asm/mach/time.h>



static unsigned long clock_count_per_tick;



static struct clk *tin2;

static struct clk *tin4;

static struct clk *tdiv2;

static struct clk *tdiv4;

static struct clk *timerclk;



static void s5pv310_pwm_stop(unsigned int pwm_id)

{

	unsigned long tcon;



	tcon = __raw_readl(S3C2410_TCON);



	switch (pwm_id) {

	case 2:

		tcon &= ~S3C2410_TCON_T2START;

		break;

	case 4:

		tcon &= ~S3C2410_TCON_T4START;

		break;

	default:

		break;

	}

	__raw_writel(tcon, S3C2410_TCON);

}



static void s5pv310_pwm_init(unsigned int pwm_id, unsigned long tcnt)

{

	unsigned long tcon;



	tcon = __raw_readl(S3C2410_TCON);



	/* timers reload after counting zero, so reduce the count by 1 */

	tcnt--;



	/* ensure timer is stopped... */

	switch (pwm_id) {

	case 2:

		tcon &= ~(0xf<<12);

		tcon |= S3C2410_TCON_T2MANUALUPD;



		__raw_writel(tcnt, S3C2410_TCNTB(2));

		__raw_writel(tcnt, S3C2410_TCMPB(2));

		__raw_writel(tcon, S3C2410_TCON);



		break;

	case 4:

		tcon &= ~(7<<20);

		tcon |= S3C2410_TCON_T4MANUALUPD;



		__raw_writel(tcnt, S3C2410_TCNTB(4));

		__raw_writel(tcnt, S3C2410_TCMPB(4));

		__raw_writel(tcon, S3C2410_TCON);



		break;

	default:

		break;

	}

}



static inline void s5pv310_pwm_start(unsigned int pwm_id, bool periodic)

{

	unsigned long tcon;



	tcon  = __raw_readl(S3C2410_TCON);



	switch (pwm_id) {

	case 2:

		tcon |= S3C2410_TCON_T2START;

		tcon &= ~S3C2410_TCON_T2MANUALUPD;



		if (periodic)

			tcon |= S3C2410_TCON_T2RELOAD;

		else

			tcon &= ~S3C2410_TCON_T2RELOAD;

		break;

	case 4:

		tcon |= S3C2410_TCON_T4START;

		tcon &= ~S3C2410_TCON_T4MANUALUPD;



		if (periodic)

			tcon |= S3C2410_TCON_T4RELOAD;

		else

			tcon &= ~S3C2410_TCON_T4RELOAD;

		break;

	default:

		break;

	}

	__raw_writel(tcon, S3C2410_TCON);

}



static int s5pv310_pwm_set_next_event(unsigned long cycles,

					struct clock_event_device *evt)

{

	s5pv310_pwm_init(2, cycles);

	s5pv310_pwm_start(2, 0);

	return 0;

}



static void s5pv310_pwm_set_mode(enum clock_event_mode mode,

				struct clock_event_device *evt)

{

	s5pv310_pwm_stop(2);



	switch (mode) {

	case CLOCK_EVT_MODE_PERIODIC:

		s5pv310_pwm_init(2, clock_count_per_tick);

		s5pv310_pwm_start(2, 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 pwm_event_device = {

	.name		= "pwm_timer2",

	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,

	.rating		= 200,

	.shift		= 32,

	.set_next_event	= s5pv310_pwm_set_next_event,

	.set_mode	= s5pv310_pwm_set_mode,

};



irqreturn_t s5pv310_clock_event_isr(int irq, void *dev_id)

{

	struct clock_event_device *evt = &pwm_event_device;



	evt->event_handler(evt);



	return IRQ_HANDLED;

}



static struct irqaction s5pv310_clock_event_irq = {

	.name		= "pwm_timer2_irq",

	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,

	.handler	= s5pv310_clock_event_isr,

};



static void __init s5pv310_clockevent_init(void)

{

	unsigned long pclk;

	unsigned long clock_rate;

	struct clk *tscaler;



	pclk = clk_get_rate(timerclk);



	/* configure clock tick */



	tscaler = clk_get_parent(tdiv2);



	clk_set_rate(tscaler, pclk / 2);

	clk_set_rate(tdiv2, pclk / 2);

	clk_set_parent(tin2, tdiv2);



	clock_rate = clk_get_rate(tin2);



	clock_count_per_tick = clock_rate / HZ;



	pwm_event_device.mult =

		div_sc(clock_rate, NSEC_PER_SEC, pwm_event_device.shift);

	pwm_event_device.max_delta_ns =

		clockevent_delta2ns(-1, &pwm_event_device);

	pwm_event_device.min_delta_ns =

		clockevent_delta2ns(1, &pwm_event_device);



	pwm_event_device.cpumask = cpumask_of(0);

	clockevents_register_device(&pwm_event_device);



	setup_irq(IRQ_TIMER2, &s5pv310_clock_event_irq);

}



static cycle_t s5pv310_pwm4_read(struct clocksource *cs)

{

	return (cycle_t) ~__raw_readl(S3C_TIMERREG(0x40));

}



struct clocksource pwm_clocksource = {

	.name		= "pwm_timer4",

	.rating		= 250,

	.read		= s5pv310_pwm4_read,

	.mask		= CLOCKSOURCE_MASK(32),

	.shift		= 20,

	.flags		= CLOCK_SOURCE_IS_CONTINUOUS ,

};



static void __init s5pv310_clocksource_init(void)

{

	unsigned long pclk;

	unsigned long clock_rate;



	pclk = clk_get_rate(timerclk);



	clk_set_rate(tdiv4, pclk / 2);

	clk_set_parent(tin4, tdiv4);



	clock_rate = clk_get_rate(tin4);



	s5pv310_pwm_init(4, ~0);

	s5pv310_pwm_start(4, 1);



	pwm_clocksource.mult =

		clocksource_khz2mult(clock_rate/1000, pwm_clocksource.shift);



	if (clocksource_register(&pwm_clocksource))

		panic("%s: can't register clocksource\n", pwm_clocksource.name);

}



static void __init s5pv310_timer_resources(void)

{

	struct platform_device tmpdev;



	tmpdev.dev.bus = &platform_bus_type;



	timerclk = clk_get(NULL, "timers");

	if (IS_ERR(timerclk))

		panic("failed to get timers clock for system timer");



	clk_enable(timerclk);



	tmpdev.id = 2;

	tin2 = clk_get(&tmpdev.dev, "pwm-tin");

	if (IS_ERR(tin2))

		panic("failed to get pwm-tin2 clock for system timer");



	tdiv2 = clk_get(&tmpdev.dev, "pwm-tdiv");

	if (IS_ERR(tdiv2))

		panic("failed to get pwm-tdiv2 clock for system timer");

	clk_enable(tin2);



	tmpdev.id = 4;

	tin4 = clk_get(&tmpdev.dev, "pwm-tin");

	if (IS_ERR(tin4))

		panic("failed to get pwm-tin4 clock for system timer");



	tdiv4 = clk_get(&tmpdev.dev, "pwm-tdiv");

	if (IS_ERR(tdiv4))

		panic("failed to get pwm-tdiv4 clock for system timer");



	clk_enable(tin4);

}



static void __init s5pv310_timer_init(void)

{

#ifdef CONFIG_LOCAL_TIMERS

	twd_base = S5P_VA_TWD;

#endif



	s5pv310_timer_resources();

	s5pv310_clockevent_init();

	s5pv310_clocksource_init();

}



struct sys_timer s5pv310_timer = {

	.init		= s5pv310_timer_init,

};

arch/arm/plat-s5p/include/plat/s5pv310.h

+1 −0
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@@ -22,6 +22,7 @@ extern int s5pv310_init(void); 
extern void s5pv310_init_irq(void);

extern void s5pv310_map_io(void);

extern void s5pv310_init_clocks(int xtal);

extern struct sys_timer s5pv310_timer;



#define s5pv310_init_uarts s5pv310_common_init_uarts

arch/arm/plat-samsung/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ obj- := 
# Objects we always build independent of SoC choice



obj-y				+= init.o

obj-y				+= time.o

obj-$(CONFIG_ARCH_USES_GETTIMEOFFSET)   += time.o

obj-y				+= clock.o

obj-y				+= pwm-clock.o

obj-y				+= gpio.o