LCOM1920-T5G03

#include <lcom/lcf.h>

#include "uart.h"

#include "errors.h"

#define UART_BITRATE                            115200

#define UART_WAIT                               20 //microseconds

#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

/// LCR

#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)

/// IER

#define UART_INT_EN_RECEIVED_DATA_POS           0

#define UART_INT_EN_TRANSMITTER_EMPTY_POS       1

#define UART_INT_EN_RECEIVER_LINE_STAT_POS      2

#define UART_INT_EN_MODEM_STAT_POS              3

#define UART_INT_EN_RECEIVED_DATA               (BIT(0))

#define UART_INT_EN_TRANSMITTER_EMPTY           (BIT(1))

#define UART_INT_EN_RECEIVER_LINE_STAT          (BIT(2))

#define UART_INT_EN_MODEM_STAT                  (BIT(3))

#define UART_INT_EN_GET_RECEIVED_DATA(n)        (((n)&UART_INT_EN_RECEIVED_DATA     )>>UART_INT_EN_RECEIVED_DATA_POS     )

#define UART_INT_EN_GET_TRANSMITTER_EMPTY(n)    (((n)&UART_INT_EN_TRANSMITTER_EMPTY )>>UART_INT_EN_TRANSMITTER_EMPTY_POS )

#define UART_INT_EN_GET_RECEIVER_LINE_STAT(n)   (((n)&UART_INT_EN_RECEIVER_LINE_STAT)>>UART_INT_EN_RECEIVER_LINE_STAT_POS)

#define UART_INT_EN_GET_MODEM_STAT(n)           (((n)&UART_INT_EN_MODEM_STAT        )>>UART_INT_EN_MODEM_STAT_POS        )

/// LSR

#define UART_RECEIVER_READY_POS                 0

#define UART_TRANSMITTER_EMPTY_POS              5

#define UART_RECEIVER_READY                     (BIT(0))

#define UART_TRANSMITTER_EMPTY                  (BIT(5))

#define UART_GET_RECEIVER_READY(n)              (((n)&UART_RECEIVER_READY           )>>UART_RECEIVER_READY_POS           )

#define UART_GET_TRANSMITTER_EMPTY(n)           (((n)&UART_TRANSMITTER_EMPTY        )>>UART_TRANSMITTER_EMPTY_POS        )

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->lcr))) return ret;

    if((ret = util_sys_inb(base_addr+UART_IER, &config->ier))) 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;

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

    uart_parse_config(config);

    return ret;

}

void uart_parse_config(uart_config *config){

    /// LCR

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

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

    config->parity                 = UART_GET_PARITY            (config->lcr); if((config->parity & BIT(0)) == 0) config->parity = uart_parity_none;

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

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

    /// IER

    config->received_data_int      = UART_INT_EN_GET_RECEIVED_DATA     (config->ier);

    config->transmitter_empty_int  = UART_INT_EN_GET_TRANSMITTER_EMPTY (config->ier);

    config->receiver_line_stat_int = UART_INT_EN_GET_RECEIVER_LINE_STAT(config->ier);

    config->modem_stat_int         = UART_INT_EN_GET_MODEM_STAT        (config->ier);

    /// DIV LATCH

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

}

void uart_print_config(uart_config config){

    printf("%s configuration:\n", (config.base_addr == COM1_ADDR ? "COM1" : "COM2"));

    printf("\tLCR = 0x%X: %d bits per char\t %d stop bits\t", config.lcr, config.bits_per_char, config.stop_bits);

    if((config.parity&BIT(0)) == 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("\tDLM = 0x%02X DLL=0x%02X: bitrate = %d bps\n", config.dlm, config.dll, UART_BITRATE/config.divisor_latch);

    printf("\tIER = 0x%02X: Rx interrupts: %s\tTx interrupts: %s\n", config.ier,

        (config.received_data_int     ? "ENABLED":"DISABLED"),

        (config.transmitter_empty_int ? "ENABLED":"DISABLED"));

}

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 = uart_disable_divisor_latch(base_addr))) return ret;

    return SUCCESS;

}

/// PRIVATE

int uart_get_lsr(int base_addr, uint8_t *p){

    return util_sys_inb(base_addr+UART_LSR, p);

}

/**

 * @brief Get char from RBR.

 */

int uart_get_char(int base_addr, uint8_t *p){

    int ret;

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

    return util_sys_inb(base_addr+UART_RBR, p);

}

int uart_send_char(int base_addr, uint8_t c){

    int ret;

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

    if(sys_outb(base_addr, c)) return WRITE_ERROR;

    return SUCCESS;

}

int uart_receiver_ready(int base_addr){

    uint8_t lsr;

    if(uart_get_lsr(base_addr, &lsr)) return false;

    return UART_GET_RECEIVER_READY(lsr);

}

int uart_transmitter_empty(int base_addr){

    uint8_t lsr;

    if(uart_get_lsr(base_addr, &lsr)) return false;

    return UART_GET_TRANSMITTER_EMPTY(lsr);

}

///PUBLIC

int uart_get_char_poll(int base_addr, uint8_t *p){

    int ret;

    while(!uart_receiver_ready(base_addr)){}

    if((ret = uart_get_char(base_addr, p))) return ret;

    return SUCCESS;

}

int uart_send_char_poll(int base_addr, uint8_t  c){

    int ret;

    while(!uart_transmitter_empty(base_addr)){}

    if((ret = uart_send_char(base_addr, c))) return ret;

    return SUCCESS;

}

int uart_send_memory_poll(int base_addr, void *str, size_t n){

    int ret;

    uint8_t *p = str;

    for(size_t i = 0; i < n; ++i, ++p){

        if((ret = uart_send_char_poll(base_addr, *p))) return ret;

    }

    return SUCCESS;

}