diff options
Diffstat (limited to 'target/linux/s3c24xx/patches/0195-From-119f4e02ba81cffe4dbc88d8ff667048ad28d925-Mon-Se.patch')
| -rwxr-xr-x | target/linux/s3c24xx/patches/0195-From-119f4e02ba81cffe4dbc88d8ff667048ad28d925-Mon-Se.patch | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/target/linux/s3c24xx/patches/0195-From-119f4e02ba81cffe4dbc88d8ff667048ad28d925-Mon-Se.patch b/target/linux/s3c24xx/patches/0195-From-119f4e02ba81cffe4dbc88d8ff667048ad28d925-Mon-Se.patch new file mode 100755 index 0000000000..1e4adc707f --- /dev/null +++ b/target/linux/s3c24xx/patches/0195-From-119f4e02ba81cffe4dbc88d8ff667048ad28d925-Mon-Se.patch @@ -0,0 +1,322 @@ +From 1cc62cde7f9717e9349f4b117900bd17750e4bf2 Mon Sep 17 00:00:00 2001 +From: Andrzej Zaborowski <balrog@zabor.org> +Date: Fri, 25 Jul 2008 23:06:17 +0100 +Subject: [PATCH] From 119f4e02ba81cffe4dbc88d8ff667048ad28d925 Mon Sep 17 00:00:00 2001 + Subject: [PATCH] Hacky CONFIG_NO_IDLE_HZ (dyn-tick) support for S3C24xx. + +--- + arch/arm/plat-s3c24xx/time.c | 247 +++++++++++++++++++++++++++++++++++------- + 1 files changed, 209 insertions(+), 38 deletions(-) + +diff --git a/arch/arm/plat-s3c24xx/time.c b/arch/arm/plat-s3c24xx/time.c +index 03b8643..8b101e0 100644 +--- a/arch/arm/plat-s3c24xx/time.c ++++ b/arch/arm/plat-s3c24xx/time.c +@@ -3,6 +3,8 @@ + * 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 +@@ -44,6 +46,9 @@ 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 +@@ -178,11 +183,7 @@ static void s3c2410_timer_setup (void) + tcfg1 &= ~S3C2410_TCFG1_MUX4_MASK; + tcfg1 |= S3C2410_TCFG1_MUX4_TCLK1; + } else { +- unsigned long pclk; +- struct clk *clk; +- +- /* for the h1940 (and others), we use the pclk from the core +- * to generate the timer values. since values around 50 to ++ /* 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. + * +@@ -190,20 +191,7 @@ static void s3c2410_timer_setup (void) + * (8.45 ticks per usec) + */ + +- /* 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); +- + /* configure clock tick */ +- + timer_usec_ticks = timer_mask_usec_ticks(6, pclk); + printk("timer_usec_ticks = %lu\n", timer_usec_ticks); + +@@ -214,11 +202,6 @@ static void s3c2410_timer_setup (void) + tcfg0 |= ((6 - 1) / 2) << S3C2410_TCFG_PRESCALER1_SHIFT; + + tcnt = (pclk / 6) / HZ; +- +- /* start the timer running */ +- tcon |= S3C2410_TCON_T4START | S3C2410_TCON_T4RELOAD; +- tcon &= ~S3C2410_TCON_T4MANUALUPD; +- __raw_writel(tcon, S3C2410_TCON); + } + + /* timers reload after counting zero, so reduce the count by 1 */ +@@ -260,27 +243,37 @@ static void s3c2410_timer_setup (void) + + } + ++struct sys_timer s3c24xx_timer; + static void timer_resume_work(struct work_struct *work) + { +- s3c2410_timer_setup(); +-} +- +-/* ooh a nasty situation arises if we try to call s3c2410_timer_setup() from +- * the resume handler. It is called in atomic context but the clock APIs +- * try to lock a mutex which may sleep. We are in a bit of an unusual +- * situation because we don't have a tick source right now, but it should be +- * okay to try to schedule a work item... hopefully +- */ +- +-static void s3c2410_timer_resume_atomic(void) +-{ +- int ret = schedule_work(&resume_work); +- if (!ret) +- printk(KERN_INFO"Failed to schedule_work tick ctr (%d)\n", ret); ++ 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); +@@ -302,8 +295,186 @@ static void s3c2410_timer_resume(void) + "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 + }; +-- +1.5.6.3 + |