[PATCH 5/8] ARM: S5PV310: Add Timer support
Kukjin Kim
kgene.kim at samsung.com
Fri Jun 25 10:27:14 EDT 2010
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: 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 | 289 ++++++++++++++++++++++++
arch/arm/plat-samsung/Makefile | 2 +-
4 files changed, 385 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..250af60
--- /dev/null
+++ b/arch/arm/mach-s5pv310/time.c
@@ -0,0 +1,289 @@
+/* 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--;
+
+ printk(KERN_DEBUG "timer tcon=%08lx, tcnt %08lx\n", tcon, 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);
+
+ 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);
+
+ s5pv310_pwm_init(2, ~0);
+ s5pv310_pwm_start(2, 1);
+}
+
+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-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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