Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 469 insertions, 0 deletions

diff --git a/arch/mips/au1000/common/time.c b/arch/mips/au1000/common/time.c
new file mode 100644
index 000000000000..fe418f1620c3
--- /dev/null
+++ b/arch/mips/au1000/common/time.c
@@ -0,0 +1,469 @@
+/*
+ *
+ * Copyright (C) 2001 MontaVista Software, ppopov@mvista.com
+ * Copied and modified Carsten Langgaard's time.c
+ *
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ * ########################################################################
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.
+ *
+ * ########################################################################
+ *
+ * Setting up the clock on the MIPS boards.
+ *
+ * Update.  Always configure the kernel with CONFIG_NEW_TIME_C.  This
+ * will use the user interface gettimeofday() functions from the
+ * arch/mips/kernel/time.c, and we provide the clock interrupt processing
+ * and the timer offset compute functions.  If CONFIG_PM is selected,
+ * we also ensure the 32KHz timer is available.   -- Dan
+ */
+
+#include <linux/types.h>
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/hardirq.h>
+
+#include <asm/compiler.h>
+#include <asm/mipsregs.h>
+#include <asm/ptrace.h>
+#include <asm/time.h>
+#include <asm/div64.h>
+#include <asm/mach-au1x00/au1000.h>
+
+#include <linux/mc146818rtc.h>
+#include <linux/timex.h>
+
+extern void startup_match20_interrupt(void);
+extern void do_softirq(void);
+extern volatile unsigned long wall_jiffies;
+unsigned long missed_heart_beats = 0;
+
+static unsigned long r4k_offset; /* Amount to increment compare reg each time */
+static unsigned long r4k_cur;    /* What counter should be at next timer irq */
+int	no_au1xxx_32khz;
+void	(*au1k_wait_ptr)(void);
+
+/* Cycle counter value at the previous timer interrupt.. */
+static unsigned int timerhi = 0, timerlo = 0;
+
+#ifdef CONFIG_PM
+#define MATCH20_INC 328
+extern void startup_match20_interrupt(void);
+static unsigned long last_pc0, last_match20;
+#endif
+
+static DEFINE_SPINLOCK(time_lock);
+
+static inline void ack_r4ktimer(unsigned long newval)
+{
+	write_c0_compare(newval);
+}
+
+/*
+ * There are a lot of conceptually broken versions of the MIPS timer interrupt
+ * handler floating around.  This one is rather different, but the algorithm
+ * is provably more robust.
+ */
+unsigned long wtimer;
+void mips_timer_interrupt(struct pt_regs *regs)
+{
+	int irq = 63;
+	unsigned long count;
+
+	irq_enter();
+	kstat_this_cpu.irqs[irq]++;
+
+	if (r4k_offset == 0)
+		goto null;
+
+	do {
+		count = read_c0_count();
+		timerhi += (count < timerlo);   /* Wrap around */
+		timerlo = count;
+
+		kstat_this_cpu.irqs[irq]++;
+		do_timer(regs);
+#ifndef CONFIG_SMP
+		update_process_times(user_mode(regs));
+#endif
+		r4k_cur += r4k_offset;
+		ack_r4ktimer(r4k_cur);
+
+	} while (((unsigned long)read_c0_count()
+	         - r4k_cur) < 0x7fffffff);
+
+	irq_exit();
+	return;
+
+null:
+	ack_r4ktimer(0);
+}
+
+#ifdef CONFIG_PM
+void counter0_irq(int irq, void *dev_id, struct pt_regs *regs)
+{
+	unsigned long pc0;
+	int time_elapsed;
+	static int jiffie_drift = 0;
+
+	kstat.irqs[0][irq]++;
+	if (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20) {
+		/* should never happen! */
+		printk(KERN_WARNING "counter 0 w status eror\n");
+		return;
+	}
+
+	pc0 = au_readl(SYS_TOYREAD);
+	if (pc0 < last_match20) {
+		/* counter overflowed */
+		time_elapsed = (0xffffffff - last_match20) + pc0;
+	}
+	else {
+		time_elapsed = pc0 - last_match20;
+	}
+
+	while (time_elapsed > 0) {
+		do_timer(regs);
+#ifndef CONFIG_SMP
+		update_process_times(user_mode(regs));
+#endif
+		time_elapsed -= MATCH20_INC;
+		last_match20 += MATCH20_INC;
+		jiffie_drift++;
+	}
+
+	last_pc0 = pc0;
+	au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2);
+	au_sync();
+
+	/* our counter ticks at 10.009765625 ms/tick, we we're running
+	 * almost 10uS too slow per tick.
+	 */
+
+	if (jiffie_drift >= 999) {
+		jiffie_drift -= 999;
+		do_timer(regs); /* increment jiffies by one */
+#ifndef CONFIG_SMP
+		update_process_times(user_mode(regs));
+#endif
+	}
+}
+
+/* When we wakeup from sleep, we have to "catch up" on all of the
+ * timer ticks we have missed.
+ */
+void
+wakeup_counter0_adjust(void)
+{
+	unsigned long pc0;
+	int time_elapsed;
+
+	pc0 = au_readl(SYS_TOYREAD);
+	if (pc0 < last_match20) {
+		/* counter overflowed */
+		time_elapsed = (0xffffffff - last_match20) + pc0;
+	}
+	else {
+		time_elapsed = pc0 - last_match20;
+	}
+
+	while (time_elapsed > 0) {
+		time_elapsed -= MATCH20_INC;
+		last_match20 += MATCH20_INC;
+	}
+
+	last_pc0 = pc0;
+	au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2);
+	au_sync();
+
+}
+
+/* This is just for debugging to set the timer for a sleep delay.
+*/
+void
+wakeup_counter0_set(int ticks)
+{
+	unsigned long pc0;
+
+	pc0 = au_readl(SYS_TOYREAD);
+	last_pc0 = pc0;
+	au_writel(last_match20 + (MATCH20_INC * ticks), SYS_TOYMATCH2);
+	au_sync();
+}
+#endif
+
+/* I haven't found anyone that doesn't use a 12 MHz source clock,
+ * but just in case.....
+ */
+#ifdef CONFIG_AU1000_SRC_CLK
+#define AU1000_SRC_CLK	CONFIG_AU1000_SRC_CLK
+#else
+#define AU1000_SRC_CLK	12000000
+#endif
+
+/*
+ * We read the real processor speed from the PLL.  This is important
+ * because it is more accurate than computing it from the 32KHz
+ * counter, if it exists.  If we don't have an accurate processor
+ * speed, all of the peripherals that derive their clocks based on
+ * this advertised speed will introduce error and sometimes not work
+ * properly.  This function is futher convoluted to still allow configurations
+ * to do that in case they have really, really old silicon with a
+ * write-only PLL register, that we need the 32KHz when power management
+ * "wait" is enabled, and we need to detect if the 32KHz isn't present
+ * but requested......got it? :-)		-- Dan
+ */
+unsigned long cal_r4koff(void)
+{
+	unsigned long count;
+	unsigned long cpu_speed;
+	unsigned long flags;
+	unsigned long counter;
+
+	spin_lock_irqsave(&time_lock, flags);
+
+	/* Power management cares if we don't have a 32KHz counter.
+	*/
+	no_au1xxx_32khz = 0;
+	counter = au_readl(SYS_COUNTER_CNTRL);
+	if (counter & SYS_CNTRL_E0) {
+		int trim_divide = 16;
+
+		au_writel(counter | SYS_CNTRL_EN1, SYS_COUNTER_CNTRL);
+
+		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
+		/* RTC now ticks at 32.768/16 kHz */
+		au_writel(trim_divide-1, SYS_RTCTRIM);
+		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S);
+
+		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
+		au_writel (0, SYS_TOYWRITE);
+		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S);
+
+#if defined(CONFIG_AU1000_USE32K)
+		{
+			unsigned long start, end;
+
+			start = au_readl(SYS_RTCREAD);
+			start += 2;
+			/* wait for the beginning of a new tick
+			*/
+			while (au_readl(SYS_RTCREAD) < start);
+
+			/* Start r4k counter.
+			*/
+			write_c0_count(0);
+
+			/* Wait 0.5 seconds.
+			*/
+			end = start + (32768 / trim_divide)/2;
+
+			while (end > au_readl(SYS_RTCREAD));
+
+			count = read_c0_count();
+			cpu_speed = count * 2;
+		}
+#else
+		cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) * 
+			AU1000_SRC_CLK;
+		count = cpu_speed / 2;
+#endif
+	}
+	else {
+		/* The 32KHz oscillator isn't running, so assume there
+		 * isn't one and grab the processor speed from the PLL.
+		 * NOTE: some old silicon doesn't allow reading the PLL.
+		 */
+		cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) * AU1000_SRC_CLK;
+		count = cpu_speed / 2;
+		no_au1xxx_32khz = 1;
+	}
+	mips_hpt_frequency = count;
+	// Equation: Baudrate = CPU / (SD * 2 * CLKDIV * 16)
+	set_au1x00_uart_baud_base(cpu_speed / (2 * ((int)(au_readl(SYS_POWERCTRL)&0x03) + 2) * 16));
+	spin_unlock_irqrestore(&time_lock, flags);
+	return (cpu_speed / HZ);
+}
+
+/* This is for machines which generate the exact clock. */
+#define USECS_PER_JIFFY (1000000/HZ)
+#define USECS_PER_JIFFY_FRAC (0x100000000LL*1000000/HZ&0xffffffff)
+
+static unsigned long
+div64_32(unsigned long v1, unsigned long v2, unsigned long v3)
+{
+	unsigned long r0;
+	do_div64_32(r0, v1, v2, v3);
+	return r0;
+}
+
+static unsigned long do_fast_cp0_gettimeoffset(void)
+{
+	u32 count;
+	unsigned long res, tmp;
+	unsigned long r0;
+
+	/* Last jiffy when do_fast_gettimeoffset() was called. */
+	static unsigned long last_jiffies=0;
+	unsigned long quotient;
+
+	/*
+	 * Cached "1/(clocks per usec)*2^32" value.
+	 * It has to be recalculated once each jiffy.
+	 */
+	static unsigned long cached_quotient=0;
+
+	tmp = jiffies;
+
+	quotient = cached_quotient;
+
+	if (tmp && last_jiffies != tmp) {
+		last_jiffies = tmp;
+		if (last_jiffies != 0) {
+			r0 = div64_32(timerhi, timerlo, tmp);
+			quotient = div64_32(USECS_PER_JIFFY, USECS_PER_JIFFY_FRAC, r0);
+			cached_quotient = quotient;
+		}
+	}
+
+	/* Get last timer tick in absolute kernel time */
+	count = read_c0_count();
+
+	/* .. relative to previous jiffy (32 bits is enough) */
+	count -= timerlo;
+
+	__asm__("multu\t%1,%2\n\t"
+		"mfhi\t%0"
+		: "=r" (res)
+		: "r" (count), "r" (quotient)
+		: "hi", "lo", GCC_REG_ACCUM);
+
+	/*
+ 	 * Due to possible jiffies inconsistencies, we need to check 
+	 * the result so that we'll get a timer that is monotonic.
+	 */
+	if (res >= USECS_PER_JIFFY)
+		res = USECS_PER_JIFFY-1;
+
+	return res;
+}
+
+#ifdef CONFIG_PM
+static unsigned long do_fast_pm_gettimeoffset(void)
+{
+	unsigned long pc0;
+	unsigned long offset;
+
+	pc0 = au_readl(SYS_TOYREAD);
+	au_sync();
+	offset = pc0 - last_pc0;
+	if (offset > 2*MATCH20_INC) {
+		printk("huge offset %x, last_pc0 %x last_match20 %x pc0 %x\n", 
+				(unsigned)offset, (unsigned)last_pc0, 
+				(unsigned)last_match20, (unsigned)pc0);
+	}
+	offset = (unsigned long)((offset * 305) / 10);
+	return offset;
+}
+#endif
+
+void au1xxx_timer_setup(struct irqaction *irq)
+{
+        unsigned int est_freq;
+	extern unsigned long (*do_gettimeoffset)(void);
+	extern void au1k_wait(void);
+
+	printk("calculating r4koff... ");
+	r4k_offset = cal_r4koff();
+	printk("%08lx(%d)\n", r4k_offset, (int) r4k_offset);
+
+	//est_freq = 2*r4k_offset*HZ;	
+	est_freq = r4k_offset*HZ;	
+	est_freq += 5000;    /* round */
+	est_freq -= est_freq%10000;
+	printk("CPU frequency %d.%02d MHz\n", est_freq/1000000, 
+	       (est_freq%1000000)*100/1000000);
+ 	set_au1x00_speed(est_freq);
+ 	set_au1x00_lcd_clock(); // program the LCD clock
+
+	r4k_cur = (read_c0_count() + r4k_offset);
+	write_c0_compare(r4k_cur);
+
+#ifdef CONFIG_PM
+	/*
+	 * setup counter 0, since it keeps ticking after a
+	 * 'wait' instruction has been executed. The CP0 timer and
+	 * counter 1 do NOT continue running after 'wait'
+	 *
+	 * It's too early to call request_irq() here, so we handle
+	 * counter 0 interrupt as a special irq and it doesn't show
+	 * up under /proc/interrupts.
+	 *
+	 * Check to ensure we really have a 32KHz oscillator before
+	 * we do this.
+	 */
+	if (no_au1xxx_32khz) {
+		unsigned int c0_status;
+
+		printk("WARNING: no 32KHz clock found.\n");
+		do_gettimeoffset = do_fast_cp0_gettimeoffset;
+
+		/* Ensure we get CPO_COUNTER interrupts.
+		*/
+		c0_status = read_c0_status();
+		c0_status |= IE_IRQ5;
+		write_c0_status(c0_status);
+	}
+	else {
+		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S);
+		au_writel(0, SYS_TOYWRITE);
+		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S);
+
+		au_writel(au_readl(SYS_WAKEMSK) | (1<<8), SYS_WAKEMSK);
+		au_writel(~0, SYS_WAKESRC);
+		au_sync();
+		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20);
+
+		/* setup match20 to interrupt once every 10ms */
+		last_pc0 = last_match20 = au_readl(SYS_TOYREAD);
+		au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2);
+		au_sync();
+		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20);
+		startup_match20_interrupt();
+
+		do_gettimeoffset = do_fast_pm_gettimeoffset;
+
+		/* We can use the real 'wait' instruction.
+		*/
+		au1k_wait_ptr = au1k_wait;
+	}
+
+#else
+	/* We have to do this here instead of in timer_init because
+	 * the generic code in arch/mips/kernel/time.c will write
+	 * over our function pointer.
+	 */
+	do_gettimeoffset = do_fast_cp0_gettimeoffset;
+#endif
+}
+
+void __init au1xxx_time_init(void)
+{
+}