[PATCH v2 5/8] ARM: S5PV310: Add Timer support
Kyungmin Park
kmpark at infradead.org
Fri Jul 16 06:30:45 EDT 2010
On Fri, Jul 16, 2010 at 5:58 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>
> ---
> 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..64accf8
> --- /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
Please make it configurable, now PWM 2 is used for I2C pin in mobile hardware.
It seems to smdk specific file.
Why don't use the systimer?
Thank you,
Kyungmin Park
> + *
> + * 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(4, cycles);
> + s5pv310_pwm_start(4, 0);
> + return 0;
> +}
> +
> +static void s5pv310_pwm_set_mode(enum clock_event_mode mode,
> + struct clock_event_device *evt)
> +{
> + s5pv310_pwm_stop(4);
> +
> + switch (mode) {
> + case CLOCK_EVT_MODE_PERIODIC:
> + s5pv310_pwm_init(4, clock_count_per_tick);
> + s5pv310_pwm_start(4, 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_timer4",
> + .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_timer4_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(tdiv4);
> +
> + clk_set_rate(tscaler, pclk / 2);
> + clk_set_rate(tdiv4, pclk / 2);
> + clk_set_parent(tin4, tdiv4);
> +
> + clock_rate = clk_get_rate(tin4);
> +
> + 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_TIMER4, &s5pv310_clock_event_irq);
> +}
> +
> +static cycle_t s5pv310_pwm2_read(struct clocksource *cs)
> +{
> + return (cycle_t) ~__raw_readl(S3C_TIMERREG(0x2c));
> +}
> +
> +struct clocksource pwm_clocksource = {
> + .name = "pwm_timer2",
> + .rating = 250,
> + .read = s5pv310_pwm2_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(tdiv2, pclk / 2);
> + clk_set_parent(tin2, tdiv2);
> +
> + clock_rate = clk_get_rate(tin2);
> +
> + s5pv310_pwm_init(2, ~0);
> + s5pv310_pwm_start(2, 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
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
More information about the linux-arm-kernel
mailing list