diff options
Diffstat (limited to 'devices/uart_16550.c')
-rw-r--r-- | devices/uart_16550.c | 117 |
1 files changed, 0 insertions, 117 deletions
diff --git a/devices/uart_16550.c b/devices/uart_16550.c deleted file mode 100644 index 1adcf38..0000000 --- a/devices/uart_16550.c +++ /dev/null @@ -1,117 +0,0 @@ -#include "uart.h" -#include <stddef.h> -#include <sys/io.h> - -enum uart_16550_offset { - Data = 0, // read from receive buffer / write to transmit buffer | BaudDiv_l - InterruptControl = 1, // interrupt enable | BaudDiv_h - FifoControl = 2, // interrupt ID and FIFO control - LineControl = 3, // most significant bit is the DLAB - ModemControl = 4, - LineStatus = 5, - ModemStatus = 6, - Scratch = 7, -}; -// Line Control -// | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | -// |dla| | parity | s | data | - -enum LineControl { - d5bit = 0x00, // 0000 0000 data bits - d6bit = 0x01, // 0000 0001 - d7bit = 0x02, // 0000 0010 - d8bit = 0x03, // 0000 0011 - // none = 0b00000000, // parity bits - odd = 0x08, // 0000 1000 - even = 0x18, // 0001 1000 - mark = 0x28, // 0010 1000 - space = 0x38, // 0011 1000 - // s1bit = 0b00000000, // stop bits - s2bit = 0x04, // 0000 0100 1.5 for 5bit data; 2 otherwise - dlab = 0x80 // 1000 0000 divisor latch access bit -}; - -// Line Status Register -enum LineStatus { - DR = (1 << 0), // data ready: see if there is data to read - OE = (1 << 1), // overrun error: see if there has been data lost - PE = (1 << 2), // parity error: see if there was error in transmission - FE = (1 << 3), // framing error: see if a stop bit was missing - BI = (1 << 4), // break indicator: see if there is a break in data input - THRE = (1 << 5), // transmitter holding register empty: see if transmission buffer is empty - TEMT = (1 << 6), // transmitter empty: see if transmitter is not doing anything - ERRO = (1 << 7), // impending error: see if there is an error with a word in the input buffer -}; - -int -uart_thre(enum UART port) -{ - return inb(port + LineStatus) & THRE; -} - -void -uart_write(const FILE *self, char a) -{ - while (uart_thre(self->id) == 0) {} - outb(a, self->id); - - if (a == '\n') { - while (uart_thre(self->id) == 0) {} - outb('\r', self->id); - } -} - -int -uart_puts(const FILE *self, const char *string, int length) -{ - int written = 0; - - if (length == -1) - while (*string != '\0') { - uart_write(self, *string); - ++string; - ++written; - } - - else - for (int i = 0; i < length; ++i) { - uart_write(self, string[i]); - ++written; - } - - return written; -} - -void -uart_flush(__attribute__((unused)) const FILE *self) -{ -} - -FILE uart_stream; - -FILE * -uart_init(enum UART port) -{ - outb(0x00, port + 1); // Disable all interrupts - outb(0x80, port + 3); // Enable DLAB (set baud rate divisor) - outb(0x03, port + 0); // Set divisor to 3 (lo byte) 38400 baud - outb(0x00, port + 1); // (hi byte) - outb(0x03, port + 3); // 8 bits, no parity, one stop bit - outb(0xc7, port + 2); // Enable FIFO, clear them, with 14-byte threshold - outb(0x0b, port + 4); // IRQs enabled, RTS/DSR set - outb(0x1e, port + 4); // Set in loopback mode, test the serial chip - outb(0xae, port + 0); // Test serial chip (send byte 0xAE and check if serial - // returns same byte) - - // Check if serial is faulty (i.e: not same byte as sent) - if (inb(port + 0) != 0xae) { return NULL; } - - // If serial is not faulty set it in normal operation mode - // (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled) - outb(0x0f, port + 4); - uart_stream.id = port; - uart_stream.putc = &uart_write; - uart_stream.puts = &uart_puts; - uart_stream.flush = &uart_flush; - return &uart_stream; -} |