diff options
author | Taru Karttunen <taruti@taruti.net> | 2011-03-30 15:46:40 +0300 |
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committer | Taru Karttunen <taruti@taruti.net> | 2011-03-30 15:46:40 +0300 |
commit | e5888a1ffdae813d7575f5fb02275c6bb07e5199 (patch) | |
tree | d8d51eac403f07814b9e936eed0c9a79195e2450 /sys/src/9/pc/uarti8250.c |
Import sources from 2011-03-30 iso image
Diffstat (limited to 'sys/src/9/pc/uarti8250.c')
-rwxr-xr-x | sys/src/9/pc/uarti8250.c | 739 |
1 files changed, 739 insertions, 0 deletions
diff --git a/sys/src/9/pc/uarti8250.c b/sys/src/9/pc/uarti8250.c new file mode 100755 index 000000000..a3caf7741 --- /dev/null +++ b/sys/src/9/pc/uarti8250.c @@ -0,0 +1,739 @@ +#include "u.h" +#include "../port/lib.h" +#include "mem.h" +#include "dat.h" +#include "fns.h" +#include "io.h" +#include "../port/error.h" + +/* + * 8250 UART and compatibles. + */ +enum { + Uart0 = 0x3F8, /* COM1 */ + Uart0IRQ = 4, + Uart1 = 0x2F8, /* COM2 */ + Uart1IRQ = 3, + + UartFREQ = 1843200, +}; + +enum { /* I/O ports */ + Rbr = 0, /* Receiver Buffer (RO) */ + Thr = 0, /* Transmitter Holding (WO) */ + Ier = 1, /* Interrupt Enable */ + Iir = 2, /* Interrupt Identification (RO) */ + Fcr = 2, /* FIFO Control (WO) */ + Lcr = 3, /* Line Control */ + Mcr = 4, /* Modem Control */ + Lsr = 5, /* Line Status */ + Msr = 6, /* Modem Status */ + Scr = 7, /* Scratch Pad */ + Dll = 0, /* Divisor Latch LSB */ + Dlm = 1, /* Divisor Latch MSB */ +}; + +enum { /* Ier */ + Erda = 0x01, /* Enable Received Data Available */ + Ethre = 0x02, /* Enable Thr Empty */ + Erls = 0x04, /* Enable Receiver Line Status */ + Ems = 0x08, /* Enable Modem Status */ +}; + +enum { /* Iir */ + Ims = 0x00, /* Ms interrupt */ + Ip = 0x01, /* Interrupt Pending (not) */ + Ithre = 0x02, /* Thr Empty */ + Irda = 0x04, /* Received Data Available */ + Irls = 0x06, /* Receiver Line Status */ + Ictoi = 0x0C, /* Character Time-out Indication */ + IirMASK = 0x3F, + Ifena = 0xC0, /* FIFOs enabled */ +}; + +enum { /* Fcr */ + FIFOena = 0x01, /* FIFO enable */ + FIFOrclr = 0x02, /* clear Rx FIFO */ + FIFOtclr = 0x04, /* clear Tx FIFO */ + FIFO1 = 0x00, /* Rx FIFO trigger level 1 byte */ + FIFO4 = 0x40, /* 4 bytes */ + FIFO8 = 0x80, /* 8 bytes */ + FIFO14 = 0xC0, /* 14 bytes */ +}; + +enum { /* Lcr */ + Wls5 = 0x00, /* Word Length Select 5 bits/byte */ + Wls6 = 0x01, /* 6 bits/byte */ + Wls7 = 0x02, /* 7 bits/byte */ + Wls8 = 0x03, /* 8 bits/byte */ + WlsMASK = 0x03, + Stb = 0x04, /* 2 stop bits */ + Pen = 0x08, /* Parity Enable */ + Eps = 0x10, /* Even Parity Select */ + Stp = 0x20, /* Stick Parity */ + Brk = 0x40, /* Break */ + Dlab = 0x80, /* Divisor Latch Access Bit */ +}; + +enum { /* Mcr */ + Dtr = 0x01, /* Data Terminal Ready */ + Rts = 0x02, /* Ready To Send */ + Out1 = 0x04, /* no longer in use */ + Ie = 0x08, /* IRQ Enable */ + Dm = 0x10, /* Diagnostic Mode loopback */ +}; + +enum { /* Lsr */ + Dr = 0x01, /* Data Ready */ + Oe = 0x02, /* Overrun Error */ + Pe = 0x04, /* Parity Error */ + Fe = 0x08, /* Framing Error */ + Bi = 0x10, /* Break Interrupt */ + Thre = 0x20, /* Thr Empty */ + Temt = 0x40, /* Tramsmitter Empty */ + FIFOerr = 0x80, /* error in receiver FIFO */ +}; + +enum { /* Msr */ + Dcts = 0x01, /* Delta Cts */ + Ddsr = 0x02, /* Delta Dsr */ + Teri = 0x04, /* Trailing Edge of Ri */ + Ddcd = 0x08, /* Delta Dcd */ + Cts = 0x10, /* Clear To Send */ + Dsr = 0x20, /* Data Set Ready */ + Ri = 0x40, /* Ring Indicator */ + Dcd = 0x80, /* Data Set Ready */ +}; + +typedef struct Ctlr { + int io; + int irq; + int tbdf; + int iena; + + uchar sticky[8]; + + Lock; + int hasfifo; + int checkfifo; + int fena; +} Ctlr; + +extern PhysUart i8250physuart; + +static Ctlr i8250ctlr[2] = { +{ .io = Uart0, + .irq = Uart0IRQ, + .tbdf = BUSUNKNOWN, }, + +{ .io = Uart1, + .irq = Uart1IRQ, + .tbdf = BUSUNKNOWN, }, +}; + +static Uart i8250uart[2] = { +{ .regs = &i8250ctlr[0], + .name = "COM1", + .freq = UartFREQ, + .phys = &i8250physuart, + .special= 0, + .next = &i8250uart[1], }, + +{ .regs = &i8250ctlr[1], + .name = "COM2", + .freq = UartFREQ, + .phys = &i8250physuart, + .special= 0, + .next = nil, }, +}; + +#define csr8r(c, r) inb((c)->io+(r)) +#define csr8w(c, r, v) outb((c)->io+(r), (c)->sticky[(r)]|(v)) + +static long +i8250status(Uart* uart, void* buf, long n, long offset) +{ + char *p; + Ctlr *ctlr; + uchar ier, lcr, mcr, msr; + + ctlr = uart->regs; + p = malloc(READSTR); + mcr = ctlr->sticky[Mcr]; + msr = csr8r(ctlr, Msr); + ier = ctlr->sticky[Ier]; + lcr = ctlr->sticky[Lcr]; + snprint(p, READSTR, + "b%d c%d d%d e%d l%d m%d p%c r%d s%d i%d\n" + "dev(%d) type(%d) framing(%d) overruns(%d) " + "berr(%d) serr(%d)%s%s%s%s\n", + + uart->baud, + uart->hup_dcd, + (msr & Dsr) != 0, + uart->hup_dsr, + (lcr & WlsMASK) + 5, + (ier & Ems) != 0, + (lcr & Pen) ? ((lcr & Eps) ? 'e': 'o'): 'n', + (mcr & Rts) != 0, + (lcr & Stb) ? 2: 1, + ctlr->fena, + + uart->dev, + uart->type, + uart->ferr, + uart->oerr, + uart->berr, + uart->serr, + (msr & Cts) ? " cts": "", + (msr & Dsr) ? " dsr": "", + (msr & Dcd) ? " dcd": "", + (msr & Ri) ? " ring": "" + ); + n = readstr(offset, buf, n, p); + free(p); + + return n; +} + +static void +i8250fifo(Uart* uart, int level) +{ + Ctlr *ctlr; + + ctlr = uart->regs; + if(ctlr->hasfifo == 0) + return; + + /* + * Changing the FIFOena bit in Fcr flushes data + * from both receive and transmit FIFOs; there's + * no easy way to guarantee not losing data on + * the receive side, but it's possible to wait until + * the transmitter is really empty. + */ + ilock(ctlr); + while(!(csr8r(ctlr, Lsr) & Temt)) + ; + + /* + * Set the trigger level, default is the max. + * value. + * Some UARTs require FIFOena to be set before + * other bits can take effect, so set it twice. + */ + ctlr->fena = level; + switch(level){ + case 0: + break; + case 1: + level = FIFO1|FIFOena; + break; + case 4: + level = FIFO4|FIFOena; + break; + case 8: + level = FIFO8|FIFOena; + break; + default: + level = FIFO14|FIFOena; + break; + } + csr8w(ctlr, Fcr, level); + csr8w(ctlr, Fcr, level); + iunlock(ctlr); +} + +static void +i8250dtr(Uart* uart, int on) +{ + Ctlr *ctlr; + + /* + * Toggle DTR. + */ + ctlr = uart->regs; + if(on) + ctlr->sticky[Mcr] |= Dtr; + else + ctlr->sticky[Mcr] &= ~Dtr; + csr8w(ctlr, Mcr, 0); +} + +static void +i8250rts(Uart* uart, int on) +{ + Ctlr *ctlr; + + /* + * Toggle RTS. + */ + ctlr = uart->regs; + if(on) + ctlr->sticky[Mcr] |= Rts; + else + ctlr->sticky[Mcr] &= ~Rts; + csr8w(ctlr, Mcr, 0); +} + +static void +i8250modemctl(Uart* uart, int on) +{ + Ctlr *ctlr; + + ctlr = uart->regs; + ilock(&uart->tlock); + if(on){ + ctlr->sticky[Ier] |= Ems; + csr8w(ctlr, Ier, ctlr->sticky[Ier]); + uart->modem = 1; + uart->cts = csr8r(ctlr, Msr) & Cts; + } + else{ + ctlr->sticky[Ier] &= ~Ems; + csr8w(ctlr, Ier, ctlr->sticky[Ier]); + uart->modem = 0; + uart->cts = 1; + } + iunlock(&uart->tlock); + + /* modem needs fifo */ + (*uart->phys->fifo)(uart, on); +} + +static int +i8250parity(Uart* uart, int parity) +{ + int lcr; + Ctlr *ctlr; + + ctlr = uart->regs; + lcr = ctlr->sticky[Lcr] & ~(Eps|Pen); + + switch(parity){ + case 'e': + lcr |= Eps|Pen; + break; + case 'o': + lcr |= Pen; + break; + case 'n': + break; + default: + return -1; + } + ctlr->sticky[Lcr] = lcr; + csr8w(ctlr, Lcr, 0); + + uart->parity = parity; + + return 0; +} + +static int +i8250stop(Uart* uart, int stop) +{ + int lcr; + Ctlr *ctlr; + + ctlr = uart->regs; + lcr = ctlr->sticky[Lcr] & ~Stb; + + switch(stop){ + case 1: + break; + case 2: + lcr |= Stb; + break; + default: + return -1; + } + ctlr->sticky[Lcr] = lcr; + csr8w(ctlr, Lcr, 0); + + uart->stop = stop; + + return 0; +} + +static int +i8250bits(Uart* uart, int bits) +{ + int lcr; + Ctlr *ctlr; + + ctlr = uart->regs; + lcr = ctlr->sticky[Lcr] & ~WlsMASK; + + switch(bits){ + case 5: + lcr |= Wls5; + break; + case 6: + lcr |= Wls6; + break; + case 7: + lcr |= Wls7; + break; + case 8: + lcr |= Wls8; + break; + default: + return -1; + } + ctlr->sticky[Lcr] = lcr; + csr8w(ctlr, Lcr, 0); + + uart->bits = bits; + + return 0; +} + +static int +i8250baud(Uart* uart, int baud) +{ + ulong bgc; + Ctlr *ctlr; + + /* + * Set the Baud rate by calculating and setting the Baud rate + * Generator Constant. This will work with fairly non-standard + * Baud rates. + */ + if(uart->freq == 0 || baud <= 0) + return -1; + bgc = (uart->freq+8*baud-1)/(16*baud); + + ctlr = uart->regs; + csr8w(ctlr, Lcr, Dlab); + outb(ctlr->io+Dlm, bgc>>8); + outb(ctlr->io+Dll, bgc); + csr8w(ctlr, Lcr, 0); + + uart->baud = baud; + + return 0; +} + +static void +i8250break(Uart* uart, int ms) +{ + Ctlr *ctlr; + + /* + * Send a break. + */ + if(ms <= 0) + ms = 200; + + ctlr = uart->regs; + csr8w(ctlr, Lcr, Brk); + tsleep(&up->sleep, return0, 0, ms); + csr8w(ctlr, Lcr, 0); +} + +static void +i8250kick(Uart* uart) +{ + int i; + Ctlr *ctlr; + + if(uart->cts == 0 || uart->blocked) + return; + + /* + * 128 here is an arbitrary limit to make sure + * we don't stay in this loop too long. If the + * chip's output queue is longer than 128, too + * bad -- presotto + */ + ctlr = uart->regs; + for(i = 0; i < 128; i++){ + if(!(csr8r(ctlr, Lsr) & Thre)) + break; + if(uart->op >= uart->oe && uartstageoutput(uart) == 0) + break; + outb(ctlr->io+Thr, *(uart->op++)); + } +} + +static void +i8250interrupt(Ureg*, void* arg) +{ + Ctlr *ctlr; + Uart *uart; + int iir, lsr, old, r; + + uart = arg; + + ctlr = uart->regs; + for(iir = csr8r(ctlr, Iir); !(iir & Ip); iir = csr8r(ctlr, Iir)){ + switch(iir & IirMASK){ + case Ims: /* Ms interrupt */ + r = csr8r(ctlr, Msr); + if(r & Dcts){ + ilock(&uart->tlock); + old = uart->cts; + uart->cts = r & Cts; + if(old == 0 && uart->cts) + uart->ctsbackoff = 2; + iunlock(&uart->tlock); + } + if(r & Ddsr){ + old = r & Dsr; + if(uart->hup_dsr && uart->dsr && !old) + uart->dohup = 1; + uart->dsr = old; + } + if(r & Ddcd){ + old = r & Dcd; + if(uart->hup_dcd && uart->dcd && !old) + uart->dohup = 1; + uart->dcd = old; + } + break; + case Ithre: /* Thr Empty */ + uartkick(uart); + break; + case Irda: /* Received Data Available */ + case Irls: /* Receiver Line Status */ + case Ictoi: /* Character Time-out Indication */ + /* + * Consume any received data. + * If the received byte came in with a break, + * parity or framing error, throw it away; + * overrun is an indication that something has + * already been tossed. + */ + while((lsr = csr8r(ctlr, Lsr)) & Dr){ + if(lsr & (FIFOerr|Oe)) + uart->oerr++; + if(lsr & Pe) + uart->perr++; + if(lsr & Fe) + uart->ferr++; + r = csr8r(ctlr, Rbr); + if(!(lsr & (Bi|Fe|Pe))) + uartrecv(uart, r); + } + break; + + default: + iprint("weird uart interrupt 0x%2.2uX\n", iir); + break; + } + } +} + +static void +i8250disable(Uart* uart) +{ + Ctlr *ctlr; + + /* + * Turn off DTR and RTS, disable interrupts and fifos. + */ + (*uart->phys->dtr)(uart, 0); + (*uart->phys->rts)(uart, 0); + (*uart->phys->fifo)(uart, 0); + + ctlr = uart->regs; + ctlr->sticky[Ier] = 0; + csr8w(ctlr, Ier, ctlr->sticky[Ier]); + + if(ctlr->iena != 0){ + if(intrdisable(ctlr->irq, i8250interrupt, uart, ctlr->tbdf, uart->name) == 0) + ctlr->iena = 0; + } +} + +static void +i8250enable(Uart* uart, int ie) +{ + Ctlr *ctlr; + + ctlr = uart->regs; + + /* + * Check if there is a FIFO. + * Changing the FIFOena bit in Fcr flushes data + * from both receive and transmit FIFOs; there's + * no easy way to guarantee not losing data on + * the receive side, but it's possible to wait until + * the transmitter is really empty. + * Also, reading the Iir outwith i8250interrupt() + * can be dangerous, but this should only happen + * once before interrupts are enabled. + */ + ilock(ctlr); + if(!ctlr->checkfifo){ + /* + * Wait until the transmitter is really empty. + */ + while(!(csr8r(ctlr, Lsr) & Temt)) + ; + csr8w(ctlr, Fcr, FIFOena); + if(csr8r(ctlr, Iir) & Ifena) + ctlr->hasfifo = 1; + csr8w(ctlr, Fcr, 0); + ctlr->checkfifo = 1; + } + iunlock(ctlr); + + /* + * Enable interrupts and turn on DTR and RTS. + * Be careful if this is called to set up a polled serial line + * early on not to try to enable interrupts as interrupt- + * -enabling mechanisms might not be set up yet. + */ + if(ie){ + if(ctlr->iena == 0){ + intrenable(ctlr->irq, i8250interrupt, uart, ctlr->tbdf, uart->name); + ctlr->iena = 1; + } + ctlr->sticky[Ier] = Ethre|Erda; + ctlr->sticky[Mcr] |= Ie; + } + else{ + ctlr->sticky[Ier] = 0; + ctlr->sticky[Mcr] = 0; + } + csr8w(ctlr, Ier, ctlr->sticky[Ier]); + csr8w(ctlr, Mcr, ctlr->sticky[Mcr]); + + (*uart->phys->dtr)(uart, 1); + (*uart->phys->rts)(uart, 1); + + /* + * During startup, the i8259 interrupt controller is reset. + * This may result in a lost interrupt from the i8250 uart. + * The i8250 thinks the interrupt is still outstanding and does not + * generate any further interrupts. The workaround is to call the + * interrupt handler to clear any pending interrupt events. + * Note: this must be done after setting Ier. + */ + if(ie) + i8250interrupt(nil, uart); +} + +void* +i8250alloc(int io, int irq, int tbdf) +{ + Ctlr *ctlr; + + if((ctlr = malloc(sizeof(Ctlr))) != nil){ + ctlr->io = io; + ctlr->irq = irq; + ctlr->tbdf = tbdf; + } + + return ctlr; +} + +static Uart* +i8250pnp(void) +{ + return i8250uart; +} + +static int +i8250getc(Uart *uart) +{ + Ctlr *ctlr; + + ctlr = uart->regs; + while(!(csr8r(ctlr, Lsr)&Dr)) + delay(1); + return csr8r(ctlr, Rbr); +} + +static void +i8250putc(Uart *uart, int c) +{ + int i; + Ctlr *ctlr; + + ctlr = uart->regs; + for(i = 0; !(csr8r(ctlr, Lsr)&Thre) && i < 128; i++) + delay(1); + outb(ctlr->io+Thr, c); + for(i = 0; !(csr8r(ctlr, Lsr)&Thre) && i < 128; i++) + delay(1); +} + +PhysUart i8250physuart = { + .name = "i8250", + .pnp = i8250pnp, + .enable = i8250enable, + .disable = i8250disable, + .kick = i8250kick, + .dobreak = i8250break, + .baud = i8250baud, + .bits = i8250bits, + .stop = i8250stop, + .parity = i8250parity, + .modemctl = i8250modemctl, + .rts = i8250rts, + .dtr = i8250dtr, + .status = i8250status, + .fifo = i8250fifo, + .getc = i8250getc, + .putc = i8250putc, +}; + +void +i8250console(void) +{ + Uart *uart; + int n; + char *cmd, *p; + + if((p = getconf("console")) == nil) + return; + n = strtoul(p, &cmd, 0); + if(p == cmd) + return; + switch(n){ + default: + return; + case 0: + uart = &i8250uart[0]; + break; + case 1: + uart = &i8250uart[1]; + break; + } + + (*uart->phys->enable)(uart, 0); + uartctl(uart, "b9600 l8 pn s1"); + if(*cmd != '\0') + uartctl(uart, cmd); + + consuart = uart; + uart->console = 1; +} + +void +i8250mouse(char* which, int (*putc)(Queue*, int), int setb1200) +{ + char *p; + int port; + + port = strtol(which, &p, 0); + if(p == which || port < 0 || port > 1) + error(Ebadarg); + uartmouse(&i8250uart[port], putc, setb1200); +} + +void +i8250setmouseputc(char* which, int (*putc)(Queue*, int)) +{ + char *p; + int port; + + port = strtol(which, &p, 0); + if(p == which || port < 0 || port > 1) + error(Ebadarg); + uartsetmouseputc(&i8250uart[port], putc); + +} |