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Sun 12 Jan 19:29:58 CET 2025

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sbosse 2025-01-12 19:30:21 +01:00
parent bab1b053bf
commit 528fc9432e
1 changed files with 55 additions and 17 deletions
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72
kernel/serial.c
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@ -16,6 +16,8 @@ See the file LICENSE for details.
#include "interrupt.h"
#include "string.h"
#include "device.h"
#include "event.h"
#include "event_queue.h"
#define COM1 0x3f8
#define COM2 0x2F8
@ -24,7 +26,8 @@ See the file LICENSE for details.
#define SERIAL_DATA 0 // If DLAB disabled in LCR
#define SERIAL_IRQ_ENABLE 1 // If DLAB disabled in LCR
#define SERIAL_IER 1
#define SERIAL_IRQ_DATA_AVAILABILE (0x01 << 0)
#define SERIAL_IRQ_TRASMITTER_EMPTY (0x01 << 1)
#define SERIAL_IRQ_ERROR (0x01 << 2)
@ -64,21 +67,32 @@ See the file LICENSE for details.
#define SERIAL_SCRATCH 7
// units 0,1,2,3
static const int serial_ports[4] = { COM1, COM2, COM3, COM4 };
static const int serial_ports_irq[4] = { 4, 3, 4, 3 };
static const int serial_ports[2] = { COM1, COM2 };
static const int serial_ports_irq[2] = { 4, 3 };
static struct event_queue *queue[2];
static void serial_interrupt(int i, int intr_code)
static void serial_interrupt(int intr, int intr_code)
{
printf("serial_interrupt %d %d\n",i,intr_code);
intr=intr-32; // reduce by IRQ table offset; IRQ is not unique! We may only support 2 COMs!
int port_no=intr==4?0:1,
port = serial_ports[port_no];
while(inb(port + SERIAL_LSR) & SERIAL_DATA_AVAILABLE) {
char ch=inb(port);
struct event e;
e.type = EVENT_DATA;
e.code = ch;
event_queue_post(queue[port_no],&e);
}
}
static void serial_init_port(int unit)
static int serial_init_port(int unit)
{
int port = serial_ports[unit];
// probe for hardware
if(inb(port+SERIAL_LSR)==0xff) return 0;
//Disable interrupts
outb(0x00, port + SERIAL_IRQ_ENABLE);
outb(0x00, port + SERIAL_IER);
//Enable DLAB(set baud rate divisor)
outb(SERIAL_DLAB_ENABLE, port + SERIAL_LCR);
//Set divisor to 3(lo byte) 38400 baud
@ -87,18 +101,24 @@ static void serial_init_port(int unit)
outb(0x00, port + SERIAL_DIVISOR_HI);
//8 bits, no parity, one stop bit
outb(SERIAL_CHARLEN_START * 3, port + SERIAL_LCR);
#ifdef SERIALFIFO
//Enable FIFO, clear them, with 14 - byte threshold
outb(SERIAL_FIFO_ENABLE | SERIAL_FIFO_CLEAR_RECEIVER | SERIAL_FIFO_CLEAR_TRANSMITTER | SERIAL_TRIGGER_LEVEL0 , port + SERIAL_FCR);
#else
outb(0 , port + SERIAL_FCR);
#endif
//IRQs enabled, RTS / DSR set
outb(SERIAL_DATA_TERMINAL_READY | SERIAL_REQUEST_TO_SEND | SERIAL_AUX_OUT2, port + SERIAL_MCR);
// setup interrupt support
interrupt_register(serial_ports_irq[unit], serial_interrupt);
interrupt_enable(serial_ports_irq[unit]);
// setup interrupt support (need to add 32 to IRQ number!!!!)
interrupt_register(32+serial_ports_irq[unit], serial_interrupt);
interrupt_enable(32+serial_ports_irq[unit]);
// + received data available
outb(0x01, port + SERIAL_IRQ_ENABLE);
outb(SERIAL_IRQ_DATA_AVAILABILE, port + SERIAL_IER);
printf("[COM%d] serial_init_port %x: ready.\n",unit,port);
queue[unit]=event_queue_create();
printf("[COM%d] serial_init_port %x: ready [IRQ=%d QUE=%x].\n",unit,port,serial_ports_irq[unit],queue[unit]);
return 1;
}
@ -117,6 +137,9 @@ static int is_valid_port(uint8_t port_no)
return port_no < sizeof(serial_ports) / sizeof(int);
}
/*
Polling read
*/
int serial_read(uint8_t port_no)
{
if(!is_valid_port(port_no))
@ -124,7 +147,21 @@ int serial_read(uint8_t port_no)
while(serial_received(serial_ports[port_no]) == 0);
printf("[COM%d]\n",port_no);
return inb(serial_ports[port_no]);
return inb(serial_ports[port_no]);
}
/*
Interrupt driven event queue (blocks process if no dat ais available)
*/
int serial_getchar(uint8_t port_no) {
struct event e;
if(!is_valid_port(port_no))
return -1;
event_queue_read(queue[port_no],&e,sizeof(e));
if(e.type==EVENT_DATA) return (int)e.code;
return -1;
}
int serial_read_nonblock(uint8_t port_no)
@ -152,7 +189,8 @@ int serial_device_probe( int unit, int *blocksize, int *nblocks, char *info )
if(unit<0 || unit>3) return 0;
// TODO probing for real hardware
// reinit, second time (first time in serial_init, but needed to register the device)
serial_init_port(unit);
int status=serial_init_port(unit);
if (!status) return -1;
*blocksize = 1;
*nblocks = 0;
strcpy(info,"serial");
@ -206,7 +244,7 @@ void serial_init()
{
int i;
for(i = 0; i < sizeof(serial_ports) / sizeof(int); i++) {
serial_init_port(i);
int status = serial_init_port(i);
}
device_driver_register(&serial_driver);
}