diff options
Diffstat (limited to 'target/linux/s3c24xx/patches-2.6.31/070-s3c24xx-time.patch')
| -rw-r--r-- | target/linux/s3c24xx/patches-2.6.31/070-s3c24xx-time.patch | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/target/linux/s3c24xx/patches-2.6.31/070-s3c24xx-time.patch b/target/linux/s3c24xx/patches-2.6.31/070-s3c24xx-time.patch new file mode 100644 index 0000000000..2a147ce25d --- /dev/null +++ b/target/linux/s3c24xx/patches-2.6.31/070-s3c24xx-time.patch @@ -0,0 +1,499 @@ +From 730b77ed17f637237c16579ad9849b2a994b61a3 Mon Sep 17 00:00:00 2001 +From: Lars-Peter Clausen <lars@metafoo.de> +Date: Tue, 21 Jul 2009 12:50:43 +0200 +Subject: [PATCH] 070-s3c24xx-time.patch + +--- + arch/arm/plat-s3c24xx/time.c | 480 ++++++++++++++++++++++++++++++++++++++++++ + 1 files changed, 480 insertions(+), 0 deletions(-) + create mode 100644 arch/arm/plat-s3c24xx/time.c + +diff --git a/arch/arm/plat-s3c24xx/time.c b/arch/arm/plat-s3c24xx/time.c +new file mode 100644 +index 0000000..713a6bc +--- /dev/null ++++ b/arch/arm/plat-s3c24xx/time.c +@@ -0,0 +1,480 @@ ++/* linux/arch/arm/plat-s3c24xx/time.c ++ * ++ * Copyright (C) 2003-2005 Simtec Electronics ++ * Ben Dooks, <ben@simtec.co.uk> ++ * ++ * dyn_tick support by Andrzej Zaborowski based on omap_dyn_tick_timer. ++ * ++ * This program is free software; you can redistribute it and/or modify ++ * it under the terms of the GNU General Public License as published by ++ * the Free Software Foundation; either version 2 of the License, or ++ * (at your option) any later version. ++ * ++ * This program is distributed in the hope that it will be useful, ++ * but WITHOUT ANY WARRANTY; without even the implied warranty of ++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ++ * GNU General Public License for more details. ++ * ++ * You should have received a copy of the GNU General Public License ++ * along with this program; if not, write to the Free Software ++ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ++ */ ++ ++#include <linux/kernel.h> ++#include <linux/sched.h> ++#include <linux/init.h> ++#include <linux/interrupt.h> ++#include <linux/irq.h> ++#include <linux/err.h> ++#include <linux/clk.h> ++ ++#include <asm/system.h> ++#include <asm/leds.h> ++#include <asm/mach-types.h> ++ ++#include <asm/io.h> ++#include <asm/irq.h> ++#include <mach/map.h> ++#include <asm/plat-s3c/regs-timer.h> ++#include <mach/regs-irq.h> ++#include <asm/mach/time.h> ++ ++#include <asm/plat-s3c24xx/clock.h> ++#include <asm/plat-s3c24xx/cpu.h> ++ ++static unsigned long timer_startval; ++static unsigned long timer_usec_ticks; ++static struct work_struct resume_work; ++ ++unsigned long pclk; ++struct clk *clk; ++ ++#define TIMER_USEC_SHIFT 16 ++ ++/* we use the shifted arithmetic to work out the ratio of timer ticks ++ * to usecs, as often the peripheral clock is not a nice even multiple ++ * of 1MHz. ++ * ++ * shift of 14 and 15 are too low for the 12MHz, 16 seems to be ok ++ * for the current HZ value of 200 without producing overflows. ++ * ++ * Original patch by Dimitry Andric, updated by Ben Dooks ++*/ ++ ++ ++/* timer_mask_usec_ticks ++ * ++ * given a clock and divisor, make the value to pass into timer_ticks_to_usec ++ * to scale the ticks into usecs ++*/ ++ ++static inline unsigned long ++timer_mask_usec_ticks(unsigned long scaler, unsigned long pclk) ++{ ++ unsigned long den = pclk / 1000; ++ ++ return ((1000 << TIMER_USEC_SHIFT) * scaler + (den >> 1)) / den; ++} ++ ++/* timer_ticks_to_usec ++ * ++ * convert timer ticks to usec. ++*/ ++ ++static inline unsigned long timer_ticks_to_usec(unsigned long ticks) ++{ ++ unsigned long res; ++ ++ res = ticks * timer_usec_ticks; ++ res += 1 << (TIMER_USEC_SHIFT - 4); /* round up slightly */ ++ ++ return res >> TIMER_USEC_SHIFT; ++} ++ ++/*** ++ * Returns microsecond since last clock interrupt. Note that interrupts ++ * will have been disabled by do_gettimeoffset() ++ * IRQs are disabled before entering here from do_gettimeofday() ++ */ ++ ++#define SRCPND_TIMER4 (1<<(IRQ_TIMER4 - IRQ_EINT0)) ++ ++unsigned long s3c2410_gettimeoffset (void) ++{ ++ unsigned long tdone; ++ unsigned long irqpend; ++ unsigned long tval; ++ ++ /* work out how many ticks have gone since last timer interrupt */ ++ ++ tval = __raw_readl(S3C2410_TCNTO(4)); ++ tdone = timer_startval - tval; ++ ++ /* check to see if there is an interrupt pending */ ++ ++ irqpend = __raw_readl(S3C2410_SRCPND); ++ if (irqpend & SRCPND_TIMER4) { ++ /* re-read the timer, and try and fix up for the missed ++ * interrupt. Note, the interrupt may go off before the ++ * timer has re-loaded from wrapping. ++ */ ++ ++ tval = __raw_readl(S3C2410_TCNTO(4)); ++ tdone = timer_startval - tval; ++ ++ if (tval != 0) ++ tdone += timer_startval; ++ } ++ ++ return timer_ticks_to_usec(tdone); ++} ++ ++ ++/* ++ * IRQ handler for the timer ++ */ ++static irqreturn_t ++s3c2410_timer_interrupt(int irq, void *dev_id) ++{ ++ timer_tick(); ++ return IRQ_HANDLED; ++} ++ ++static struct irqaction s3c2410_timer_irq = { ++ .name = "S3C2410 Timer Tick", ++ .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, ++ .handler = s3c2410_timer_interrupt, ++}; ++ ++#define use_tclk1_12() ( \ ++ machine_is_bast() || \ ++ machine_is_vr1000() || \ ++ machine_is_anubis() || \ ++ machine_is_osiris() ) ++ ++/* ++ * Set up timer interrupt, and return the current time in seconds. ++ * ++ * Currently we only use timer4, as it is the only timer which has no ++ * other function that can be exploited externally ++ */ ++static void s3c2410_timer_setup (void) ++{ ++ unsigned long tcon; ++ unsigned long tcnt; ++ unsigned long tcfg1; ++ unsigned long tcfg0; ++ ++ tcnt = 0xffff; /* default value for tcnt */ ++ ++ /* read the current timer configuration bits */ ++ ++ tcon = __raw_readl(S3C2410_TCON); ++ tcfg1 = __raw_readl(S3C2410_TCFG1); ++ tcfg0 = __raw_readl(S3C2410_TCFG0); ++ ++ /* configure the system for whichever machine is in use */ ++ ++ if (use_tclk1_12()) { ++ /* timer is at 12MHz, scaler is 1 */ ++ timer_usec_ticks = timer_mask_usec_ticks(1, 12000000); ++ tcnt = 12000000 / HZ; ++ ++ tcfg1 &= ~S3C2410_TCFG1_MUX4_MASK; ++ tcfg1 |= S3C2410_TCFG1_MUX4_TCLK1; ++ } else { ++ /* since values around 50 to ++ * 70MHz are not values we can directly generate the timer ++ * value from, we need to pre-scale and divide before using it. ++ * ++ * for instance, using 50.7MHz and dividing by 6 gives 8.45MHz ++ * (8.45 ticks per usec) ++ */ ++ ++ /* configure clock tick */ ++ timer_usec_ticks = timer_mask_usec_ticks(6, pclk); ++ printk("timer_usec_ticks = %lu\n", timer_usec_ticks); ++ ++ tcfg1 &= ~S3C2410_TCFG1_MUX4_MASK; ++ tcfg1 |= S3C2410_TCFG1_MUX4_DIV2; ++ ++ tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK; ++ tcfg0 |= ((6 - 1) / 2) << S3C2410_TCFG_PRESCALER1_SHIFT; ++ ++ tcnt = (pclk / 6) / HZ; ++ } ++ ++ /* timers reload after counting zero, so reduce the count by 1 */ ++ ++ tcnt--; ++ ++ printk("timer tcon=%08lx, tcnt %04lx, tcfg %08lx,%08lx, usec %08lx\n", ++ tcon, tcnt, tcfg0, tcfg1, timer_usec_ticks); ++ ++ /* check to see if timer is within 16bit range... */ ++ if (tcnt > 0xffff) { ++ panic("setup_timer: HZ is too small, cannot configure timer!"); ++ return; ++ } ++ ++ __raw_writel(tcfg1, S3C2410_TCFG1); ++ __raw_writel(tcfg0, S3C2410_TCFG0); ++ ++ timer_startval = tcnt; ++ __raw_writel(tcnt, S3C2410_TCNTB(4)); ++ ++ /* ensure timer is stopped... */ ++ ++ tcon &= ~(7<<20); ++ tcon |= S3C2410_TCON_T4RELOAD; ++ tcon |= S3C2410_TCON_T4MANUALUPD; ++ ++ __raw_writel(tcon, S3C2410_TCON); ++ __raw_writel(tcnt, S3C2410_TCNTB(4)); ++ __raw_writel(tcnt, S3C2410_TCMPB(4)); ++ ++ /* start the timer running */ ++ tcon |= S3C2410_TCON_T4START; ++ tcon &= ~S3C2410_TCON_T4MANUALUPD; ++ __raw_writel(tcon, S3C2410_TCON); ++ ++ __raw_writel(__raw_readl(S3C2410_INTMSK) & (~(1UL << 14)), ++ S3C2410_INTMSK); ++ ++} ++ ++struct sys_timer s3c24xx_timer; ++static void timer_resume_work(struct work_struct *work) ++{ ++ clk_enable(clk); ++ ++#ifdef CONFIG_NO_IDLE_HZ ++ if (s3c24xx_timer.dyn_tick->state & DYN_TICK_ENABLED) ++ s3c24xx_timer.dyn_tick->enable(); ++ else ++#endif ++ s3c2410_timer_setup(); ++} ++ ++static void __init s3c2410_timer_init (void) ++{ ++ if (!use_tclk1_12()) { ++ /* for the h1940 (and others), we use the pclk from the core ++ * to generate the timer values. ++ */ ++ ++ /* this is used as default if no other timer can be found */ ++ clk = clk_get(NULL, "timers"); ++ if (IS_ERR(clk)) ++ panic("failed to get clock for system timer"); ++ ++ clk_enable(clk); ++ ++ pclk = clk_get_rate(clk); ++ printk("pclk = %lu\n", pclk); ++ } ++ ++ INIT_WORK(&resume_work, timer_resume_work); ++ s3c2410_timer_setup(); ++ setup_irq(IRQ_TIMER4, &s3c2410_timer_irq); ++} ++ ++static void s3c2410_timer_resume_work(struct work_struct *work) ++{ ++ s3c2410_timer_setup(); ++} ++ ++static void s3c2410_timer_resume(void) ++{ ++ static DECLARE_WORK(work, s3c2410_timer_resume_work); ++ int res; ++ ++ res = schedule_work(&work); ++ if (!res) ++ printk(KERN_ERR ++ "s3c2410_timer_resume_work already queued ???\n"); ++} ++ ++#ifdef CONFIG_NO_IDLE_HZ ++/* ++ * We'll set a constant prescaler so we don't have to bother setting it ++ * when reprogramming and so that we avoid costly divisions. ++ * ++ * (2 * HZ) << INPUT_FREQ_SHIFT is the desired frequency after prescaler. ++ * At HZ == 200, HZ * 1024 should work for PCLKs of up to ~53.5 MHz. ++ */ ++#define INPUT_FREQ_SHIFT 9 ++ ++static int ticks_last; ++static int ticks_left; ++static uint32_t tcnto_last; ++ ++static inline int s3c24xx_timer_read(void) ++{ ++ uint32_t tcnto = __raw_readl(S3C2410_TCNTO(4)); ++ ++ /* ++ * WARNING: sometimes we get called before TCNTB has been ++ * loaded into the counter and TCNTO then returns its previous ++ * value and kill us, so don't do anything before counter is ++ * reloaded. ++ */ ++ if (unlikely(tcnto == tcnto_last)) ++ return ticks_last; ++ ++ tcnto_last = -1; ++ return tcnto << ++ ((__raw_readl(S3C2410_TCFG1) >> S3C2410_TCFG1_MUX4_SHIFT) & 3); ++} ++ ++static inline void s3c24xx_timer_program(int ticks) ++{ ++ uint32_t tcon = __raw_readl(S3C2410_TCON) & ~(7 << 20); ++ uint32_t tcfg1 = __raw_readl(S3C2410_TCFG1) & ~S3C2410_TCFG1_MUX4_MASK; ++ ++ /* Just make sure the timer is stopped. */ ++ __raw_writel(tcon, S3C2410_TCON); ++ ++ /* TODO: add likely()ies / unlikely()ies */ ++ if (ticks >> 18) { ++ ticks_last = min(ticks, 0xffff << 3); ++ ticks_left = ticks - ticks_last; ++ __raw_writel(tcfg1 | S3C2410_TCFG1_MUX4_DIV16, S3C2410_TCFG1); ++ __raw_writel(ticks_last >> 3, S3C2410_TCNTB(4)); ++ } else if (ticks >> 17) { ++ ticks_last = ticks; ++ ticks_left = 0; ++ __raw_writel(tcfg1 | S3C2410_TCFG1_MUX4_DIV8, S3C2410_TCFG1); ++ __raw_writel(ticks_last >> 2, S3C2410_TCNTB(4)); ++ } else if (ticks >> 16) { ++ ticks_last = ticks; ++ ticks_left = 0; ++ __raw_writel(tcfg1 | S3C2410_TCFG1_MUX4_DIV4, S3C2410_TCFG1); ++ __raw_writel(ticks_last >> 1, S3C2410_TCNTB(4)); ++ } else { ++ ticks_last = ticks; ++ ticks_left = 0; ++ __raw_writel(tcfg1 | S3C2410_TCFG1_MUX4_DIV2, S3C2410_TCFG1); ++ __raw_writel(ticks_last >> 0, S3C2410_TCNTB(4)); ++ } ++ ++ tcnto_last = __raw_readl(S3C2410_TCNTO(4)); ++ __raw_writel(tcon | S3C2410_TCON_T4MANUALUPD, ++ S3C2410_TCON); ++ __raw_writel(tcon | S3C2410_TCON_T4START, ++ S3C2410_TCON); ++} ++ ++/* ++ * If we have already waited all the time we were supposed to wait, ++ * kick the timer, setting the longest allowed timeout value just ++ * for time-keeping. ++ */ ++static inline void s3c24xx_timer_program_idle(void) ++{ ++ s3c24xx_timer_program(0xffff << 3); ++} ++ ++static inline void s3c24xx_timer_update(int restart) ++{ ++ int ticks_cur = s3c24xx_timer_read(); ++ int jiffies_elapsed = (ticks_last - ticks_cur) >> INPUT_FREQ_SHIFT; ++ int subjiffy = ticks_last - (jiffies_elapsed << INPUT_FREQ_SHIFT); ++ ++ if (restart) { ++ if (ticks_left >= (1 << INPUT_FREQ_SHIFT)) ++ s3c24xx_timer_program(ticks_left); ++ else ++ s3c24xx_timer_program_idle(); ++ ticks_last += subjiffy; ++ } else ++ ticks_last = subjiffy; ++ ++ while (jiffies_elapsed --) ++ timer_tick(); ++} ++ ++/* Called when the timer expires. */ ++static irqreturn_t s3c24xx_timer_handler(int irq, void *dev_id) ++{ ++ tcnto_last = -1; ++ s3c24xx_timer_update(1); ++ ++ return IRQ_HANDLED; ++} ++ ++/* Called to update jiffies with time elapsed. */ ++static irqreturn_t s3c24xx_timer_handler_dyn_tick(int irq, void *dev_id) ++{ ++ s3c24xx_timer_update(0); ++ ++ return IRQ_HANDLED; ++} ++ ++/* ++ * Programs the next timer interrupt needed. Called when dynamic tick is ++ * enabled, and to reprogram the ticks to skip from pm_idle. The CPU goes ++ * to sleep directly after this. ++ */ ++static void s3c24xx_timer_reprogram_dyn_tick(unsigned long next_jiffies) ++{ ++ int subjiffy_left = ticks_last - s3c24xx_timer_read(); ++ ++ s3c24xx_timer_program(max((int) next_jiffies, 1) << INPUT_FREQ_SHIFT); ++ ticks_last += subjiffy_left; ++} ++ ++static unsigned long s3c24xx_timer_offset_dyn_tick(void) ++{ ++ /* TODO */ ++ return 0; ++} ++ ++static int s3c24xx_timer_enable_dyn_tick(void) ++{ ++ /* Set our constant prescaler. */ ++ uint32_t tcfg0 = __raw_readl(S3C2410_TCFG0); ++ int prescaler = ++ max(min(256, (int) pclk / (HZ << (INPUT_FREQ_SHIFT + 1))), 1); ++ ++ tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK; ++ tcfg0 |= (prescaler - 1) << S3C2410_TCFG_PRESCALER1_SHIFT; ++ __raw_writel(tcfg0, S3C2410_TCFG0); ++ ++ /* Override handlers. */ ++ s3c2410_timer_irq.handler = s3c24xx_timer_handler; ++ s3c24xx_timer.offset = s3c24xx_timer_offset_dyn_tick; ++ ++ printk(KERN_INFO "dyn_tick enabled on s3c24xx timer 4, " ++ "%li Hz pclk with prescaler %i\n", pclk, prescaler); ++ ++ s3c24xx_timer_program_idle(); ++ ++ return 0; ++} ++ ++static int s3c24xx_timer_disable_dyn_tick(void) ++{ ++ s3c2410_timer_irq.handler = s3c2410_timer_interrupt; ++ s3c24xx_timer.offset = s3c2410_gettimeoffset; ++ s3c2410_timer_setup(); ++ ++ return 0; ++} ++ ++static struct dyn_tick_timer s3c24xx_dyn_tick_timer = { ++ .enable = s3c24xx_timer_enable_dyn_tick, ++ .disable = s3c24xx_timer_disable_dyn_tick, ++ .reprogram = s3c24xx_timer_reprogram_dyn_tick, ++ .handler = s3c24xx_timer_handler_dyn_tick, ++}; ++#endif /* CONFIG_NO_IDLE_HZ */ ++ ++struct sys_timer s3c24xx_timer = { ++ .init = s3c2410_timer_init, ++ .offset = s3c2410_gettimeoffset, ++ .resume = s3c2410_timer_resume, ++#ifdef CONFIG_NO_IDLE_HZ ++ .dyn_tick = &s3c24xx_dyn_tick_timer, ++#endif ++}; +-- +1.5.6.5 + |