[PATCH v4 5/8] ARM: S5PV310: Add Timer support
Sangbeom Kim
sbkim73 at samsung.com
Tue Jul 27 00:58:02 EDT 2010
Thanks for your answer,
If you want use to GPD0[2] as I2C_7, you can use it as I2C port.
Because We don't use PWM2 Tout.
We only use pwm timer2 for internal operation.
Thanks,
Kyungmin Park <kmpark at infradead.org> wrote:
>On Tue, Jul 27, 2010 at 1:12 PM, Sangbeom Kim <sbkim73 at samsung.com> wrote:
>> Hi! Kyungmin,
>>
>> After booting, clock event is generated by 2 arm private timers.
>> What do you mean by 'change the pwm2 pin to i2c functions' ?
>> What do you use for I2C emulation? (TOUT2 or gpio)
>> Could you explain it in detail?
>
>In the spec, PWM2 is muxed with I2C_7. I muxed it I2C pin to use i2c chip.
>
>Thank you,
>Kyungmin Park
>>
>> Thanks and regards,
>> Sangbeom Kim
>>
>> Kyungmin Park <kmpark at infradead.org> wrote:
>>
>>>Can you confirm that during boot time, change the pwm2 pin to i2c
>>>functions and still it's working correctly?
>>>
>>>1. pwm2 is used for clock event at first boot.
>>>2. during i2c init, pwm2 pin is changed to i2c functionality.
>>>
>>>then where can get the clockevent?
>>>
>>>Another possible scenarios is that.
>>>pwm2 pin is changed to i2c function at bootloader to access the i2c
chips.
>>>Then below code is working?
>>>
>>>Thank you,
>>>Kyungmin Park
>>>
>>>On Mon, Jul 26, 2010 at 9:42 PM, Kukjin Kim <kgene.kim at samsung.com>
wrote:
>>>> From: Changhwan Youn <chaos.youn at samsung.com>
>>>>
>>>> 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: Changhwan Youn <chaos.youn at samsung.com>
>>>> Signed-off-by: Hyuk Lee <hyuk1.lee at samsung.com>
>>>> Signed-off-by: Kukjin Kim <kgene.kim at samsung.com>
>>>> ---
>>>> Changes since v3:
>>>>
>>>> - Changes clock source from PWM2 to PWM4 because PWM4 cannot be used
>for
>>>> other purpose such as external output function through GPIO.
>>>>
>>>> arch/arm/mach-s5pv310/include/mach/pwm-clock.h | 70 ++++++
>>>> arch/arm/mach-s5pv310/localtimer.c | 25 ++
>>>> arch/arm/mach-s5pv310/time.c | 287
>>>++++++++++++++++++++++++
>>>> arch/arm/plat-s5p/include/plat/s5pv310.h | 1 +
>>>> arch/arm/plat-samsung/Makefile | 2 +-
>>>> 5 files changed, 384 insertions(+), 1 deletions(-)
>>>> create mode 100644 arch/arm/mach-s5pv310/include/mach/pwm-clock.h
>>>> create mode 100644 arch/arm/mach-s5pv310/localtimer.c
>>>> create mode 100644 arch/arm/mach-s5pv310/time.c
>>>>
>>>> diff --git a/arch/arm/mach-s5pv310/include/mach/pwm-clock.h
>>>b/arch/arm/mach-s5pv310/include/mach/pwm-clock.h
>>>> new file mode 100644
>>>> index 0000000..7e6da27
>>>> --- /dev/null
>>>> +++ b/arch/arm/mach-s5pv310/include/mach/pwm-clock.h
>>>> @@ -0,0 +1,70 @@
>>>> +/* 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 at 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 */
>>>> diff --git a/arch/arm/mach-s5pv310/localtimer.c b/arch/arm/mach-
>>>s5pv310/localtimer.c
>>>> new file mode 100644
>>>> index 0000000..2784036
>>>> --- /dev/null
>>>> +++ b/arch/arm/mach-s5pv310/localtimer.c
>>>> @@ -0,0 +1,25 @@
>>>> +/* 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);
>>>> +}
>>>> diff --git a/arch/arm/mach-s5pv310/time.c b/arch/arm/mach-
>s5pv310/time.c
>>>> new file mode 100644
>>>> index 0000000..01b012a
>>>> --- /dev/null
>>>> +++ b/arch/arm/mach-s5pv310/time.c
>>>> @@ -0,0 +1,287 @@
>>>> +/* 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,
>>>> +};
>>>> diff --git a/arch/arm/plat-s5p/include/plat/s5pv310.h b/arch/arm/plat-
>>>s5p/include/plat/s5pv310.h
>>>> index d2f05e1..769c991 100644
>>>> --- a/arch/arm/plat-s5p/include/plat/s5pv310.h
>>>> +++ b/arch/arm/plat-s5p/include/plat/s5pv310.h
>>>> @@ -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
>>>>
>>>> diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-
>>>samsung/Makefile
>>>> index b1d82cc..0d5bf8a 100644
>>>> --- a/arch/arm/plat-samsung/Makefile
>>>> +++ b/arch/arm/plat-samsung/Makefile
>>>> @@ -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
>>>> --
>>>> 1.6.2.5
>>>>
>>>> --
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>samsung-
>>>soc" in
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>>>>
>>>
>>>_______________________________________________
>>>linux-arm-kernel mailing list
>>>linux-arm-kernel at lists.infradead.org
>>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
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