LCOM1920-T5G03

#include <lcom/lcf.h>

#include "uart.h"

#include "errors.h"

#define UART_RBR            0

#define UART_THR            0

#define UART_IER            1

#define UART_IIR            2

#define UART_FCR            2

#define UART_LCR            3

#define UART_MCR            4

#define UART_LSR            5

#define UART_MSR            6

#define UART_SR             7

#define UART_DLL            0

#define UART_DLM            1

#define UART_BITS_PER_CHAR_POS 0

#define UART_STOP_BITS_POS     2

#define UART_PARITY_POS        3

#define UART_BREAK_CONTROL_POS 6

#define UART_DLAB_POS          7

#define UART_BITS_PER_CHAR  (BIT(0) | BIT(1))

#define UART_STOP_BITS      (BIT(2))

#define UART_PARITY         (BIT(3) | BIT(4) | BIT(5))

#define UART_BREAK_CONTROL  (BIT(6))

#define UART_DLAB           (BIT(7))

#define UART_GET_BITS_PER_CHAR(n) (((n)&UART_BITS_PER_CHAR) + 5)

#define UART_GET_STOP_BITS(n)     (((n)&UART_STOP_BITS)? 2 : 1)

#define UART_GET_PARITY(n)        (((n)&UART_PARITY       )>>UART_PARITY_POS       )

#define UART_GET_BREAK_CONTROL(n) (((n)&UART_BREAK_CONTROL)>>UART_BREAK_CONTROL_POS)

#define UART_GET_DLAB(n)          (((n)&UART_DLAB         )>>UART_DLAB_POS         )

#define UART_GET_DIV_LATCH(m,l)   ((m)<<8 | (l))

#define UART_GET_DLL(n)           ((n)&0xFF)

#define UART_GET_DLM(n)           (((n)>>8)&0xFF)

int uart_get_config(int base_addr, uart_config *config){

    int ret = SUCCESS;

    config->base_addr = base_addr;

    if((ret = util_sys_inb(base_addr+UART_LCR, &config->config))) return ret;

    if((ret = uart_enable_divisor_latch(base_addr))) return ret;

    if((ret = util_sys_inb(base_addr+UART_DLL, &config->dll   ))) return ret;

    if((ret = util_sys_inb(base_addr+UART_DLM, &config->dlm   ))) return ret;

    uart_parse_config(config);

    return ret;

}

void uart_parse_config(uart_config *config){

    config->bits_per_char        = UART_GET_BITS_PER_CHAR(config->config);

    config->stop_bits            = UART_GET_STOP_BITS    (config->config);

    config->parity               = UART_GET_PARITY       (config->config);

    config->break_control        = UART_GET_BREAK_CONTROL(config->config);

    config->dlab                 = UART_GET_DLAB         (config->config);

    config->divisor_latch        = UART_GET_DIV_LATCH    (config->dlm, config->dll);

}

void uart_print_config(uart_config config){

    printf("Base address: 0x%X\n", config.base_addr);

    printf("Configuration: 0x%02X\n", config.config);

    printf("Number of bits per char: %d\n", config.bits_per_char);

    printf("Number of stop bits: %d\n", config.stop_bits);

    printf("Parity: ");

    if((config.parity&1) == 0) printf("no parity\n");

    else switch(config.parity){

        case uart_parity_odd : printf("odd parity\n"     ); break;

        case uart_parity_even: printf("even parity\n"    ); break;

        case uart_parity_par1: printf("parity bit is 1\n"); break;

        case uart_parity_par0: printf("parity bit is 0\n"); break;

        default              : printf("invalid\n"        ); break;

    }

    printf("Break control: %d\n", config.break_control);

    printf("Divisor latch: %d\n", config.divisor_latch);

    printf("Bit rate: %d\n", UART_BITRATE/config.divisor_latch);

}

int uart_enable_divisor_latch(int base_addr){

    int ret = SUCCESS;

    uint8_t conf; if((ret = util_sys_inb(base_addr+UART_LCR, &conf))) return ret;

    return uart_write_config(base_addr, conf | UART_DLAB);

}

int uart_disable_divisor_latch(int base_addr){

    int ret = SUCCESS;

    uint8_t conf; if((ret = util_sys_inb(base_addr+UART_LCR, &conf))) return ret;

    return uart_write_config(base_addr, conf & (~UART_DLAB));

}

int uart_write_config(int base_addr, uint8_t config){

    if(sys_outb(base_addr+UART_LCR, config)) return WRITE_ERROR;

    return SUCCESS;

}

int uart_set_bits_per_character(int base_addr, uint8_t bits_per_char){

    if(bits_per_char < 5 || bits_per_char > 8) return INVALID_ARG;

    int ret = SUCCESS;

    bits_per_char = (bits_per_char-5)&0x3;

    uint8_t conf; if((ret = util_sys_inb(base_addr+UART_LCR, &conf))) return ret;

    conf = (conf & (~UART_BITS_PER_CHAR)) | bits_per_char;

    return uart_write_config(base_addr, conf);

}

int uart_set_stop_bits(int base_addr, uint8_t stop){

    if(stop != 1 && stop != 2) return INVALID_ARG;

    int ret = SUCCESS;

    stop -= 1;

    stop = (stop&1)<<2;

    uint8_t conf; if((ret = util_sys_inb(base_addr+UART_LCR, &conf))) return ret;

    conf = (conf & (~UART_STOP_BITS)) | stop;

    return uart_write_config(base_addr, conf);

}

int uart_set_parity(int base_addr, uart_parity par){

    int ret = SUCCESS;

    uint8_t parity = par << 3;

    uint8_t conf; if((ret = util_sys_inb(base_addr+UART_LCR, &conf))) return ret;

    conf = (conf & (~UART_PARITY)) | parity;

    return uart_write_config(base_addr, conf);

}

int uart_set_bit_rate(int base_addr, float bit_rate){

    int ret = SUCCESS;

    uint16_t latch = UART_BITRATE/bit_rate;

    uint8_t dll = UART_GET_DLL(latch);

    uint8_t dlm = UART_GET_DLM(latch);

    if((ret = uart_enable_divisor_latch(base_addr))) return ret;

    if(sys_outb(base_addr+UART_DLL, dll)) return WRITE_ERROR;

    if(sys_outb(base_addr+UART_DLM, dlm)) return WRITE_ERROR;

    if((ret = util_sys_inb(base_addr+UART_DLM, &dlm))) return ret;

    return SUCCESS;

}