[MIPS] Fixup migration to GENERIC_TIME

Since we already moved to GENERIC_TIME, we should implement alternatives
of old do_gettimeoffset routines to get sub-jiffies resolution from
gettimeofday().  This patch includes:

 * MIPS clocksource support (based on works by Manish Lachwani).
 * remove unused gettimeoffset routines and related codes.
 * remove unised 64bit do_div64_32().
 * simplify mips_hpt_init. (no argument needed, __init tag)
 * simplify c0_hpt_timer_init. (no need to write to c0_count)
 * remove some hpt_init routines.
 * mips_hpt_mask variable to specify bitmask of hpt value.
 * convert jmr3927_do_gettimeoffset to jmr3927_hpt_read.
 * convert ip27_do_gettimeoffset to ip27_hpt_read.
 * convert bcm1480_do_gettimeoffset to bcm1480_hpt_read.
 * simplify sb1250 hpt functions. (no need to subtract and shift)
    
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 0 insertions, 98 deletions

diff --git a/arch/mips/au1000/common/time.c b/arch/mips/au1000/common/time.c
index 6768638883ea..fa1c62f05515 100644
--- a/arch/mips/au1000/common/time.c
+++ b/arch/mips/au1000/common/time.c
@@ -53,9 +53,6 @@ static unsigned long r4k_cur;    /* What counter should be at next timer irq */
 int     no_au1xxx_32khz;
 extern int allow_au1k_wait; /* default off for CP0 Counter */
 
-/* Cycle counter value at the previous timer interrupt.. */
-static unsigned int timerhi = 0, timerlo = 0;
-
 #ifdef CONFIG_PM
 #if HZ < 100 || HZ > 1000
 #error "unsupported HZ value! Must be in [100,1000]"
@@ -90,10 +87,6 @@ void mips_timer_interrupt(void)
                 goto null;
 
         do {
-                count = read_c0_count();
-                timerhi += (count < timerlo);   /* Wrap around */
-                timerlo = count;
-
                 kstat_this_cpu.irqs[irq]++;
                 do_timer(1);
 #ifndef CONFIG_SMP
@@ -297,88 +290,6 @@ unsigned long cal_r4koff(void)
         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 __init plat_timer_setup(struct irqaction *irq)
 {
         unsigned int est_freq;
@@ -416,7 +327,6 @@ void __init plat_timer_setup(struct irqaction *irq)
                 unsigned int c0_status;
 
                 printk("WARNING: no 32KHz clock found.\n");
-                do_gettimeoffset = do_fast_cp0_gettimeoffset;
 
                 /* Ensure we get CPO_COUNTER interrupts.
                 */
@@ -441,19 +351,11 @@ void __init plat_timer_setup(struct irqaction *irq)
                 while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20);
                 startup_match20_interrupt(counter0_irq);
 
-                do_gettimeoffset = do_fast_pm_gettimeoffset;
-
                 /* We can use the real 'wait' instruction.
                 */
                 allow_au1k_wait = 1;
         }
 
-#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
 }