LCOM1920-T5G03

#include <lcom/lcf.h>

#include "timer.h"

#include "i8254.h"

#include "utils.h"

#include "errors.h"

//7.1 timer_test_read_config()

int (timer_get_conf)(uint8_t timer, uint8_t *st) {

    if(st == NULL) return 1;

    // Write read-back command to TIMER_CTRL

    u32_t cmd = TIMER_RB_CMD | TIMER_RB_COUNT_ | TIMER_RB_SEL(timer);

    if(sys_outb(TIMER_CTRL, cmd)) return 1;

    int read_port;

    switch(timer) {

        case 0: read_port = TIMER_0; break;

        case 1: read_port = TIMER_1; break;

        case 2: read_port = TIMER_2; break;

        default: return 1;

    }

    if(util_sys_inb(read_port, st)) return 1;

    return 0;

}

int (timer_display_conf)(uint8_t timer, uint8_t st, enum timer_status_field field) {

    union timer_status_field_val conf;

    uint8_t in_mode;

    switch(field){

        case tsf_all:

            conf.byte = st; /* Full Status Byte */

            break;

        case tsf_initial:

            /* Counter Initial Value Loading Mode */

            in_mode = (st & TIMER_INMODE_MASK) >> TIMER_INMODE_POS;

            switch(in_mode){

                case 0: conf.in_mode = INVAL_val    ; break; //000

                case 1: conf.in_mode = LSB_only     ; break; //001

                case 2: conf.in_mode = MSB_only     ; break; //010

                case 3: conf.in_mode = MSB_after_LSB; break; //011

                default: return 1;

            }

            break;

        case tsf_mode:

            /* Counting Mode */

            conf.count_mode = (st & TIMER_MODE_MASK)>>TIMER_MODE_POS;

            if(conf.count_mode == TIMER_MODE_2ALT || conf.count_mode == TIMER_MODE_3ALT)

                conf.count_mode &= TIMER_MODE_RED2;

            break;

        case tsf_base:

            /* Representation of Counter Initial Value */

            conf.bcd = st & TIMER_BCD;

            break;

        default: return 1;

    }

    if(timer_print_config(timer, field, conf)) return 1;

    return 0;

}

//7.2 timer_test_time_base()

int (timer_set_frequency)(uint8_t timer, uint32_t freq) {

    // Frequencies out this range are not supported (by limitation of hardware)

    if (freq > TIMER_FREQ || freq < TIMER_MIN_FREQ) {

        printf("%s: Frequency out of range, must be between %d and %d.\n", __func__, TIMER_MIN_FREQ, TIMER_FREQ);

        return 1;

    }

    uint8_t status = 0;

    if (timer_get_conf(timer, &status)) return 1;

    //Make command

    uint8_t write_cmd = 0;

    //Select timer

    switch(timer) {

        case 0: write_cmd |= TIMER_SEL0; break;

        case 1: write_cmd |= TIMER_SEL1; break;

        case 2: write_cmd |= TIMER_SEL2; break;

        default: return 1;

    }

    //Change both LSB and MSB

    write_cmd |= TIMER_LSB_MSB;

    //Keep 4 least significant bits

    write_cmd |= (status & (TIMER_MODE_MASK | TIMER_BCD));

    //Write cmd

    if (sys_outb(TIMER_CTRL, write_cmd)) return 1;

    // counter_init = clock/freq

    uint16_t counter_init = (uint16_t)(TIMER_FREQ / freq);

    int timer_port = 0;

    switch(timer) {

        case 0: timer_port = TIMER_0; break;

        case 1: timer_port = TIMER_1; break;

        case 2: timer_port = TIMER_2; break;

        default: return 1;

    }

    uint8_t lsb = 0, msb = 0;

    /* Split the 16 bits word in two bytes */

    if (util_get_LSB(counter_init, &lsb)) return 1;

    if (util_get_MSB(counter_init, &msb)) return 1;

    /* Write the 8 LSB of the counter */

    if (sys_outb(timer_port, lsb)) return 1;

    /* Write the 8 MSB of the counter */

    if (sys_outb(timer_port, msb)) return 1;

    return 0;

}

//7.3 timer_test_int()

void (timer_int_handler)(void) {

    no_interrupts++;

}

#ifdef LAB2

    static int hook_id;

    int (timer_subscribe_int)(uint8_t *bit_no) {

        if(bit_no == NULL) return NULL_PTR;

        hook_id = 2;

        *bit_no = hook_id;

        return sys_irqsetpolicy(TIMER0_IRQ, IRQ_REENABLE, &hook_id);

    }

    int (timer_unsubscribe_int)() {

        return unsubscribe_interrupt(&hook_id);

    }

#endif

int (subscribe_timer_interrupt)(uint8_t interrupt_bit, int *interrupt_id) {

    if (interrupt_id == NULL) return 1;

    *interrupt_id = interrupt_bit;

    return (sys_irqsetpolicy(TIMER0_IRQ, IRQ_REENABLE, interrupt_id));

}

uint32_t no_interrupts = 0;