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Diffstat (limited to 'arch/v850/kernel/highres_timer.c')
| -rw-r--r-- | arch/v850/kernel/highres_timer.c | 132 |
1 files changed, 0 insertions, 132 deletions
diff --git a/arch/v850/kernel/highres_timer.c b/arch/v850/kernel/highres_timer.c deleted file mode 100644 index b16ad1e..0000000 --- a/arch/v850/kernel/highres_timer.c +++ /dev/null @@ -1,132 +0,0 @@ -/* - * arch/v850/kernel/highres_timer.c -- High resolution timing routines - * - * Copyright (C) 2001,02,03 NEC Electronics Corporation - * Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org> - * - * This file is subject to the terms and conditions of the GNU General - * Public License. See the file COPYING in the main directory of this - * archive for more details. - * - * Written by Miles Bader <miles@gnu.org> - */ - -#include <asm/system.h> -#include <asm/v850e_timer_d.h> -#include <asm/highres_timer.h> - -#define HIGHRES_TIMER_USEC_SHIFT 12 - -/* Pre-calculated constant used for converting ticks to real time - units. We initialize it to prevent it being put into BSS. */ -static u32 highres_timer_usec_prescale = 1; - -void highres_timer_slow_tick_irq (void) __attribute__ ((noreturn)); -void highres_timer_slow_tick_irq (void) -{ - /* This is an interrupt handler, so it must be very careful to - not to trash any registers. At this point, the stack-pointer - (r3) has been saved in the chip ram location ENTRY_SP by the - interrupt vector, so we can use it as a scratch register; we - must also restore it before returning. */ - asm ("ld.w %0[r0], sp;" - "add 1, sp;" - "st.w sp, %0[r0];" - "ld.w %1[r0], sp;" /* restore pre-irq stack-pointer */ - "reti" - :: - "i" (HIGHRES_TIMER_SLOW_TICKS_ADDR), - "i" (ENTRY_SP_ADDR) - : "memory"); -} - -void highres_timer_reset (void) -{ - V850E_TIMER_D_TMD (HIGHRES_TIMER_TIMER_D_UNIT) = 0; - HIGHRES_TIMER_SLOW_TICKS = 0; -} - -void highres_timer_start (void) -{ - u32 fast_tick_rate; - - /* Start hardware timer. */ - v850e_timer_d_configure (HIGHRES_TIMER_TIMER_D_UNIT, - HIGHRES_TIMER_SLOW_TICK_RATE); - - fast_tick_rate = - (V850E_TIMER_D_BASE_FREQ - >> V850E_TIMER_D_DIVLOG2 (HIGHRES_TIMER_TIMER_D_UNIT)); - - /* The obvious way of calculating microseconds from fast ticks - is to do: - - usec = fast_ticks * 10^6 / fast_tick_rate - - However, divisions are much slower than multiplications, and - the above calculation can overflow, so we do this instead: - - usec = fast_ticks * (10^6 * 2^12 / fast_tick_rate) / 2^12 - - since we can pre-calculate (10^6 * (2^12 / fast_tick_rate)) - and use a shift for dividing by 2^12, this avoids division, - and is almost as accurate (it differs by about 2 microseconds - at the extreme value of the fast-tick counter's ranger). */ - highres_timer_usec_prescale = ((1000000 << HIGHRES_TIMER_USEC_SHIFT) - / fast_tick_rate); - - /* Enable the interrupt (which is hardwired to this use), and - give it the highest priority. */ - V850E_INTC_IC (IRQ_INTCMD (HIGHRES_TIMER_TIMER_D_UNIT)) = 0; -} - -void highres_timer_stop (void) -{ - /* Stop the timer. */ - V850E_TIMER_D_TMCD (HIGHRES_TIMER_TIMER_D_UNIT) = - V850E_TIMER_D_TMCD_CAE; - /* Disable its interrupt, just in case. */ - v850e_intc_disable_irq (IRQ_INTCMD (HIGHRES_TIMER_TIMER_D_UNIT)); -} - -inline void highres_timer_read_ticks (u32 *slow_ticks, u32 *fast_ticks) -{ - int flags; - u32 fast_ticks_1, fast_ticks_2, _slow_ticks; - - local_irq_save (flags); - fast_ticks_1 = V850E_TIMER_D_TMD (HIGHRES_TIMER_TIMER_D_UNIT); - _slow_ticks = HIGHRES_TIMER_SLOW_TICKS; - fast_ticks_2 = V850E_TIMER_D_TMD (HIGHRES_TIMER_TIMER_D_UNIT); - local_irq_restore (flags); - - if (fast_ticks_2 < fast_ticks_1) - _slow_ticks++; - - *slow_ticks = _slow_ticks; - *fast_ticks = fast_ticks_2; -} - -inline void highres_timer_ticks_to_timeval (u32 slow_ticks, u32 fast_ticks, - struct timeval *tv) -{ - unsigned long sec, sec_rem, usec; - - usec = ((fast_ticks * highres_timer_usec_prescale) - >> HIGHRES_TIMER_USEC_SHIFT); - - sec = slow_ticks / HIGHRES_TIMER_SLOW_TICK_RATE; - sec_rem = slow_ticks % HIGHRES_TIMER_SLOW_TICK_RATE; - - usec += sec_rem * (1000000 / HIGHRES_TIMER_SLOW_TICK_RATE); - - tv->tv_sec = sec; - tv->tv_usec = usec; -} - -void highres_timer_read (struct timeval *tv) -{ - u32 fast_ticks, slow_ticks; - highres_timer_read_ticks (&slow_ticks, &fast_ticks); - highres_timer_ticks_to_timeval (slow_ticks, fast_ticks, tv); -} |
