897c23faca
* Implementing some serial port control in preparation to do debugging with bochs * Changed naming of io to fb_ports to finally[tm] ports
39 lines
1.0 KiB
C
39 lines
1.0 KiB
C
#include "serial.h"
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/*
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* SERIAL_LINE_COMMAND_PORT configuration
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* Bit: | 7 | 6 | 5 4 3 | 2 | 1 0 |
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* Content: | d | b | prty | s | dl |
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* d = enable/disable DLAB
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* b = enable/disable break control
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* prty = # of parity bits to use
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* s = # no of stop bits [0 is 1] and [1 is 1.5 or 2]
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* dl = length of data
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*
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*/
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void serial_set_buad_rate(const u16 com_port, const u16 divisor) {
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// Activate line - ready to send higher 8 bits of data
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// send the higher 8 bits first
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// send the lower 8 bits next
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serial_control(SERIAL_LINE_COMMAND_PORT(com_port),
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SERIAL_LINE_ENABLE);
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serial_control(SERIAL_DATA_PORT(com_port),
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(divisor>>8) & 0x00ff);
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serial_control(SERIAL_DATA_PORT(com_port),
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divisor & 0x00ff);
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}
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// Payload described above
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void serial_configure_line(const u16 line, const u8 payload) {
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serial_control(SERIAL_LINE_COMMAND_PORT(line), payload);
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}
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u8 serial_fifo_empty(const u16 com_port) {
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// If the 5th bit is set then we know that the fifo queue is empty
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return serial_read_buffer(SERIAL_LINE_STATUS_PORT(com_port)) & 0x20;
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}
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