root / lab2 / src / timer.c @ 357
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1 | 196 | up20180642 | #include <lcom/lcf.h> |
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2 | |||
3 | #include "timer.h" |
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4 | |||
5 | #include "i8254.h" |
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6 | #include "utils.h" |
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7 | #include "errors.h" |
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8 | |||
9 | //7.1 timer_test_read_config()
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10 | int (timer_get_conf)(uint8_t timer, uint8_t *st) {
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11 | if(st == NULL) return 1; |
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12 | // Write read-back command to TIMER_CTRL
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13 | u32_t cmd = TIMER_RB_CMD | TIMER_RB_COUNT_ | TIMER_RB_SEL(timer); |
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14 | if(sys_outb(TIMER_CTRL, cmd)) return 1; |
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15 | int read_port;
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16 | switch(timer) {
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17 | case 0: read_port = TIMER_0; break; |
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18 | case 1: read_port = TIMER_1; break; |
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19 | case 2: read_port = TIMER_2; break; |
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20 | default: return 1; |
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21 | } |
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22 | if(util_sys_inb(read_port, st)) return 1; |
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23 | return 0; |
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24 | } |
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25 | int (timer_display_conf)(uint8_t timer, uint8_t st, enum timer_status_field field) { |
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26 | union timer_status_field_val conf;
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27 | uint8_t in_mode; |
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28 | switch(field){
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29 | case tsf_all:
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30 | conf.byte = st; /* Full Status Byte */
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31 | break;
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32 | case tsf_initial:
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33 | /* Counter Initial Value Loading Mode */
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34 | in_mode = (st & TIMER_INMODE_MASK) >> TIMER_INMODE_POS; |
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35 | switch(in_mode){
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36 | case 0: conf.in_mode = INVAL_val ; break; //000 |
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37 | case 1: conf.in_mode = LSB_only ; break; //001 |
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38 | case 2: conf.in_mode = MSB_only ; break; //010 |
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39 | case 3: conf.in_mode = MSB_after_LSB; break; //011 |
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40 | default: return 1; |
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41 | } |
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42 | break;
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43 | case tsf_mode:
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44 | /* Counting Mode */
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45 | conf.count_mode = (st & TIMER_MODE_MASK)>>TIMER_MODE_POS; |
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46 | if(conf.count_mode == TIMER_MODE_2ALT || conf.count_mode == TIMER_MODE_3ALT)
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47 | conf.count_mode &= TIMER_MODE_RED2; |
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48 | break;
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49 | case tsf_base:
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50 | /* Representation of Counter Initial Value */
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51 | conf.bcd = st & TIMER_BCD; |
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52 | break;
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53 | default: return 1; |
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54 | } |
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55 | if(timer_print_config(timer, field, conf)) return 1; |
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56 | return 0; |
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57 | } |
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58 | //7.2 timer_test_time_base()
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59 | int (timer_set_frequency)(uint8_t timer, uint32_t freq) {
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60 | |||
61 | // Frequencies out this range are not supported (by limitation of hardware)
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62 | if (freq > TIMER_FREQ || freq < TIMER_MIN_FREQ) {
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63 | printf("%s: Frequency out of range, must be between %d and %d.\n", __func__, TIMER_MIN_FREQ, TIMER_FREQ);
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64 | return 1; |
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65 | } |
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66 | |||
67 | uint8_t status = 0;
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68 | if (timer_get_conf(timer, &status)) return 1; |
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69 | //Make command
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70 | uint8_t write_cmd = 0;
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71 | //Select timer
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72 | switch(timer) {
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73 | case 0: write_cmd |= TIMER_SEL0; break; |
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74 | case 1: write_cmd |= TIMER_SEL1; break; |
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75 | case 2: write_cmd |= TIMER_SEL2; break; |
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76 | default: return 1; |
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77 | } |
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78 | //Change both LSB and MSB
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79 | write_cmd |= TIMER_LSB_MSB; |
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80 | //Keep 4 least significant bits
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81 | write_cmd |= (status & (TIMER_MODE_MASK | TIMER_BCD)); |
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82 | //Write cmd
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83 | if (sys_outb(TIMER_CTRL, write_cmd)) return 1; |
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84 | |||
85 | // counter_init = clock/freq
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86 | uint16_t counter_init = (uint16_t)(TIMER_FREQ / freq); |
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87 | |||
88 | int timer_port = 0; |
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89 | switch(timer) {
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90 | case 0: timer_port = TIMER_0; break; |
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91 | case 1: timer_port = TIMER_1; break; |
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92 | case 2: timer_port = TIMER_2; break; |
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93 | default: return 1; |
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94 | } |
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95 | uint8_t lsb = 0, msb = 0; |
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96 | /* Split the 16 bits word in two bytes */
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97 | if (util_get_LSB(counter_init, &lsb)) return 1; |
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98 | if (util_get_MSB(counter_init, &msb)) return 1; |
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99 | |||
100 | /* Write the 8 LSB of the counter */
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101 | if (sys_outb(timer_port, lsb)) return 1; |
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102 | /* Write the 8 MSB of the counter */
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103 | if (sys_outb(timer_port, msb)) return 1; |
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104 | |||
105 | return 0; |
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106 | } |
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107 | //7.3 timer_test_int()
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108 | void (timer_int_handler)(void) { |
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109 | no_interrupts++; |
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110 | } |
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111 | #ifdef LAB2
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112 | static int hook_id; |
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113 | int (timer_subscribe_int)(uint8_t *bit_no) {
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114 | if(bit_no == NULL) return NULL_PTR; |
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115 | hook_id = 2;
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116 | *bit_no = hook_id; |
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117 | return sys_irqsetpolicy(TIMER0_IRQ, IRQ_REENABLE, &hook_id);
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118 | } |
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119 | int (timer_unsubscribe_int)() {
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120 | return unsubscribe_interrupt(&hook_id);
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121 | } |
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122 | #endif
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123 | int (subscribe_timer_interrupt)(uint8_t interrupt_bit, int *interrupt_id) { |
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124 | if (interrupt_id == NULL) return 1; |
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125 | *interrupt_id = interrupt_bit; |
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126 | return (sys_irqsetpolicy(TIMER0_IRQ, IRQ_REENABLE, interrupt_id));
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127 | } |
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128 | uint32_t no_interrupts = 0; |