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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-15 00:42:43 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-15 00:42:43 +0400 |
commit | 2cf4d4514d5b43c1f3b64bd0ec8b9853bde8f1dc (patch) | |
tree | e35a625496acc6ac852846d40b8851186b9d1ac4 /arch/arm/kernel/smp_twd.c | |
parent | 44b7532b8b464f606053562400719c9c21276037 (diff) | |
parent | ce53895a5d24e0ee19fb92f56c17323fb4c9ab27 (diff) | |
download | linux-2cf4d4514d5b43c1f3b64bd0ec8b9853bde8f1dc.tar.xz |
Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (417 commits)
MAINTAINERS: EB110ATX is not ebsa110
MAINTAINERS: update Eric Miao's email address and status
fb: add support of LCD display controller on pxa168/910 (base layer)
[ARM] 5552/1: ep93xx get_uart_rate(): use EP93XX_SYSCON_PWRCNT and EP93XX_SYSCON_PWRCN
[ARM] pxa/sharpsl_pm: zaurus needs generic pxa suspend/resume routines
[ARM] 5544/1: Trust PrimeCell resource sizes
[ARM] pxa/sharpsl_pm: cleanup of gpio-related code.
[ARM] pxa/sharpsl_pm: drop set_irq_type calls
[ARM] pxa/sharpsl_pm: merge pxa-specific code into generic one
[ARM] pxa/sharpsl_pm: merge the two sharpsl_pm.c since it's now pxa specific
[ARM] sa1100: remove unused collie_pm.c
[ARM] pxa: fix the conflicting non-static declarations of global_gpios[]
[ARM] 5550/1: Add default configure file for w90p910 platform
[ARM] 5549/1: Add clock api for w90p910 platform.
[ARM] 5548/1: Add gpio api for w90p910 platform
[ARM] 5551/1: Add multi-function pin api for w90p910 platform.
[ARM] Make ARM_VIC_NR depend on ARM_VIC
[ARM] 5546/1: ARM PL022 SSP/SPI driver v3
ARM: OMAP4: SMP: Update defconfig for OMAP4430
ARM: OMAP4: SMP: Enable SMP support for OMAP4430
...
Diffstat (limited to 'arch/arm/kernel/smp_twd.c')
-rw-r--r-- | arch/arm/kernel/smp_twd.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c new file mode 100644 index 000000000000..d8c88c633c6f --- /dev/null +++ b/arch/arm/kernel/smp_twd.c @@ -0,0 +1,175 @@ +/* + * linux/arch/arm/kernel/smp_twd.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/init.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/smp.h> +#include <linux/jiffies.h> +#include <linux/clockchips.h> +#include <linux/irq.h> +#include <linux/io.h> + +#include <asm/smp_twd.h> +#include <asm/hardware/gic.h> + +#define TWD_TIMER_LOAD 0x00 +#define TWD_TIMER_COUNTER 0x04 +#define TWD_TIMER_CONTROL 0x08 +#define TWD_TIMER_INTSTAT 0x0C + +#define TWD_WDOG_LOAD 0x20 +#define TWD_WDOG_COUNTER 0x24 +#define TWD_WDOG_CONTROL 0x28 +#define TWD_WDOG_INTSTAT 0x2C +#define TWD_WDOG_RESETSTAT 0x30 +#define TWD_WDOG_DISABLE 0x34 + +#define TWD_TIMER_CONTROL_ENABLE (1 << 0) +#define TWD_TIMER_CONTROL_ONESHOT (0 << 1) +#define TWD_TIMER_CONTROL_PERIODIC (1 << 1) +#define TWD_TIMER_CONTROL_IT_ENABLE (1 << 2) + +/* set up by the platform code */ +void __iomem *twd_base; + +static unsigned long twd_timer_rate; + +static void twd_set_mode(enum clock_event_mode mode, + struct clock_event_device *clk) +{ + unsigned long ctrl; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* timer load already set up */ + ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE + | TWD_TIMER_CONTROL_PERIODIC; + break; + case CLOCK_EVT_MODE_ONESHOT: + /* period set, and timer enabled in 'next_event' hook */ + ctrl = TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_ONESHOT; + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + default: + ctrl = 0; + } + + __raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL); +} + +static int twd_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + unsigned long ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL); + + ctrl |= TWD_TIMER_CONTROL_ENABLE; + + __raw_writel(evt, twd_base + TWD_TIMER_COUNTER); + __raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL); + + return 0; +} + +/* + * local_timer_ack: checks for a local timer interrupt. + * + * If a local timer interrupt has occurred, acknowledge and return 1. + * Otherwise, return 0. + */ +int twd_timer_ack(void) +{ + if (__raw_readl(twd_base + TWD_TIMER_INTSTAT)) { + __raw_writel(1, twd_base + TWD_TIMER_INTSTAT); + return 1; + } + + return 0; +} + +static void __cpuinit twd_calibrate_rate(void) +{ + unsigned long load, count; + u64 waitjiffies; + + /* + * If this is the first time round, we need to work out how fast + * the timer ticks + */ + if (twd_timer_rate == 0) { + printk(KERN_INFO "Calibrating local timer... "); + + /* Wait for a tick to start */ + waitjiffies = get_jiffies_64() + 1; + + while (get_jiffies_64() < waitjiffies) + udelay(10); + + /* OK, now the tick has started, let's get the timer going */ + waitjiffies += 5; + + /* enable, no interrupt or reload */ + __raw_writel(0x1, twd_base + TWD_TIMER_CONTROL); + + /* maximum value */ + __raw_writel(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER); + + while (get_jiffies_64() < waitjiffies) + udelay(10); + + count = __raw_readl(twd_base + TWD_TIMER_COUNTER); + + twd_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5); + + printk("%lu.%02luMHz.\n", twd_timer_rate / 1000000, + (twd_timer_rate / 100000) % 100); + } + + load = twd_timer_rate / HZ; + + __raw_writel(load, twd_base + TWD_TIMER_LOAD); +} + +/* + * Setup the local clock events for a CPU. + */ +void __cpuinit twd_timer_setup(struct clock_event_device *clk) +{ + unsigned long flags; + + twd_calibrate_rate(); + + clk->name = "local_timer"; + clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + clk->rating = 350; + clk->set_mode = twd_set_mode; + clk->set_next_event = twd_set_next_event; + clk->shift = 20; + clk->mult = div_sc(twd_timer_rate, NSEC_PER_SEC, clk->shift); + clk->max_delta_ns = clockevent_delta2ns(0xffffffff, clk); + clk->min_delta_ns = clockevent_delta2ns(0xf, clk); + + /* Make sure our local interrupt controller has this enabled */ + local_irq_save(flags); + get_irq_chip(clk->irq)->unmask(clk->irq); + local_irq_restore(flags); + + clockevents_register_device(clk); +} + +/* + * take a local timer down + */ +void __cpuexit twd_timer_stop(void) +{ + __raw_writel(0, twd_base + TWD_TIMER_CONTROL); +} |