[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>

include/asm-mips/div64.h

@@ -82,27 +82,6 @@
 
 #if (_MIPS_SZLONG == 64)
 
-/*
- * Don't use this one in new code
- */
-#define do_div64_32(res, high, low, base) ({ \
-	unsigned int __quot, __mod; \
-	unsigned long __div; \
-	unsigned int __low, __high, __base; \
-	\
-	__high = (high); \
-	__low = (low); \
-	__div = __high; \
-	__div = __div << 32 | __low; \
-	__base = (base); \
-	\
-	__mod = __div % __base; \
-	__div = __div / __base; \
-	\
-	__quot = __div; \
-	(res) = __quot; \
-	__mod; })
-
 /*
  * Hey, we're already 64-bit, no
  * need to play games..

include/asm-mips/sibyte/sb1250.h

@@ -51,8 +51,8 @@ extern void sb1250_mask_irq(int cpu, int irq);
 extern void sb1250_unmask_irq(int cpu, int irq);
 extern void sb1250_smp_finish(void);
 
+extern void bcm1480_hpt_setup(void);
 extern void bcm1480_time_init(void);
-extern unsigned long bcm1480_gettimeoffset(void);
 extern void bcm1480_mask_irq(int cpu, int irq);
 extern void bcm1480_unmask_irq(int cpu, int irq);
 extern void bcm1480_smp_finish(void);

include/asm-mips/time.h

@@ -48,7 +48,8 @@ extern void (*mips_timer_ack)(void);
  * If mips_hpt_read is NULL, an R4k-compatible timer setup is attempted.
  */
 extern unsigned int (*mips_hpt_read)(void);
-extern void (*mips_hpt_init)(unsigned int);
+extern void (*mips_hpt_init)(void);
+extern unsigned int mips_hpt_mask;
 
 /*
  * to_tm() converts system time back to (year, mon, day, hour, min, sec).
@@ -57,13 +58,6 @@ extern void (*mips_hpt_init)(unsigned int);
  */
 extern void to_tm(unsigned long tim, struct rtc_time *tm);
 
-/*
- * do_gettimeoffset(). By default, this func pointer points to
- * do_null_gettimeoffset(), which leads to the same resolution as HZ.
- * Higher resolution versions are available, which give ~1us resolution.
- */
-extern unsigned long (*do_gettimeoffset)(void);
-
 /*
  * high-level timer interrupt routines.
  */