| 34 | #endif /* RT_USING_DM */ |
| 35 | |
| 36 | rt_inline rt_uint32_t timeout_calc(rt_hwtimer_t *timer, rt_hwtimerval_t *tv) |
| 37 | { |
| 38 | float overflow; |
| 39 | float timeout; |
| 40 | rt_uint32_t counter; |
| 41 | int i, index = 0; |
| 42 | float tv_sec; |
| 43 | float devi_min = 1; |
| 44 | float devi; |
| 45 | |
| 46 | /* changed to second */ |
| 47 | overflow = timer->info->maxcnt/(float)timer->freq; |
| 48 | tv_sec = tv->sec + tv->usec/(float)1000000; |
| 49 | |
| 50 | if (tv_sec < (1/(float)timer->freq)) |
| 51 | { |
| 52 | /* little timeout */ |
| 53 | i = 0; |
| 54 | timeout = 1/(float)timer->freq; |
| 55 | } |
| 56 | else |
| 57 | { |
| 58 | for (i = 1; i > 0; i ++) |
| 59 | { |
| 60 | timeout = tv_sec/i; |
| 61 | |
| 62 | if (timeout <= overflow) |
| 63 | { |
| 64 | counter = (rt_uint32_t)(timeout * timer->freq); |
| 65 | devi = tv_sec - (counter / (float)timer->freq) * i; |
| 66 | /* Minimum calculation error */ |
| 67 | if (devi > devi_min) |
| 68 | { |
| 69 | i = index; |
| 70 | timeout = tv_sec/i; |
| 71 | break; |
| 72 | } |
| 73 | else if (devi == 0) |
| 74 | { |
| 75 | break; |
| 76 | } |
| 77 | else if (devi < devi_min) |
| 78 | { |
| 79 | devi_min = devi; |
| 80 | index = i; |
| 81 | } |
| 82 | } |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | timer->cycles = i; |
| 87 | timer->reload = i; |
| 88 | timer->period_sec = timeout; |
| 89 | counter = (rt_uint32_t)(timeout * timer->freq); |
| 90 | |
| 91 | return counter; |
| 92 | } |
| 93 | |