diff options
Diffstat (limited to 'arch/arm/mach-s3c2410/time.c')
| -rw-r--r-- | arch/arm/mach-s3c2410/time.c | 262 |
1 files changed, 0 insertions, 262 deletions
diff --git a/arch/arm/mach-s3c2410/time.c b/arch/arm/mach-s3c2410/time.c deleted file mode 100644 index 9910bf0f2ce..00000000000 --- a/arch/arm/mach-s3c2410/time.c +++ /dev/null @@ -1,262 +0,0 @@ -/* linux/arch/arm/mach-s3c2410/time.c - * - * Copyright (C) 2003-2005 Simtec Electronics - * Ben Dooks, <ben@simtec.co.uk> - * - * 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 <asm/arch/map.h> -#include <asm/arch/regs-timer.h> -#include <asm/arch/regs-irq.h> -#include <asm/mach/time.h> - -#include "clock.h" -#include "cpu.h" - -static unsigned long timer_startval; -static unsigned long timer_usec_ticks; - -#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)) - -static 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) -{ - write_seqlock(&xtime_lock); - timer_tick(); - write_sequnlock(&xtime_lock); - return IRQ_HANDLED; -} - -static struct irqaction s3c2410_timer_irq = { - .name = "S3C2410 Timer Tick", - .flags = IRQF_DISABLED | IRQF_TIMER, - .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 { - 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 - * 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) - */ - - /* 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); - - /* configure clock tick */ - - timer_usec_ticks = timer_mask_usec_ticks(6, pclk); - - 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); -} - -static void __init s3c2410_timer_init (void) -{ - s3c2410_timer_setup(); - setup_irq(IRQ_TIMER4, &s3c2410_timer_irq); -} - -struct sys_timer s3c24xx_timer = { - .init = s3c2410_timer_init, - .offset = s3c2410_gettimeoffset, - .resume = s3c2410_timer_setup -}; |