1990/0227/power/devbit.c (diff list | history)

power/devbit.c on 1990/0227
1990/0227		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "errno.h" #include "devtab.h" #include "io.h" typedef struct Bitmsg Bitmsg; struct Bitmsg { ulong cmd; ulong addr; ulong count; ulong result; }; static struct { QLock; int open; Bitmsg msg; char buf[10*1024]; }bit; #define BITADDR ((Bitmsg**)(KZERO+0x7C)) #define BITINTR ((char*)(UNCACHED|0x17c12001)) enum { RESET, READ, WRITE, }; void bitsend(ulong cmd, void *addr, ulong count) { bit.msg.cmd = cmd; bit.msg.addr = (ulong)addr; bit.msg.count = count; if(*BITADDR) panic("bitsend"); *BITADDR = &bit.msg; wbflush(); *BITINTR = 0x20; } void bitsync(void) { while(*BITADDR) ; } void bitreset(void) { *BITADDR = 0; qlock(&bit); qunlock(&bit); } void bitinit(void) { } Chan* bitattach(char *spec) { return devattach('b', spec); } Chan* bitclone(Chan *c, Chan *nc) { return devclone(c, nc); } int bitwalk(Chan *c, char *name) { if(c->qid != CHDIR) return 0; if(strcmp(name, "bit") == 0){ c->qid = 1; return 1; } return 0; } void bitstat(Chan *c, char *dp) { print("bitstat\n"); error(0, Egreg); } Chan* bitopen(Chan *c, int omode) { if(c->qid!=1 || omode!=ORDWR) error(0, Eperm); qlock(&bit); if(bit.open){ qunlock(&bit); print("multiple bit open\n"); error(0, Einuse); } bitsync(); bitsend(RESET, 0, 0); bitsync(); bit.open = 1; qunlock(&bit); c->mode = openmode(omode); c->flag |= COPEN; c->offset = 0; return c; } void bitcreate(Chan *c, char *name, int omode, ulong perm) { error(0, Eperm); } void bitclose(Chan *c) { qlock(&bit); bit.open = 0; qunlock(&bit); } /* * Read and write use physical addresses if they can, which they usually can. * Most I/O is from devmnt, which has local buffers. Therefore just check * that buf is in KSEG0 and is at an even address. The only killer is that * DMA counts from the bit device are mod 256, so devmnt must use oversize * buffers. */ long bitread(Chan *c, void *buf, long n) { switch(c->qid){ case 1: if(n > sizeof bit.buf) error(0, Egreg); qlock(&bit); if((((ulong)buf)&(KSEGM|3)) == KSEG0){ bitsend(READ, buf, n); bitsync(); }else{ bitsend(READ, bit.buf, n); bitsync(); memcpy(buf, bit.buf, n); } n = bit.msg.result; qunlock(&bit); return n; } error(0, Egreg); return 0; } long bitwrite(Chan *c, void *buf, long n) { switch(c->qid){ case 1: if(n > sizeof bit.buf) error(0, Egreg); qlock(&bit); if((((ulong)buf)&(KSEGM|3)) == KSEG0){ bitsend(WRITE, buf, n); bitsync(); }else{ memcpy(bit.buf, buf, n); bitsend(WRITE, bit.buf, n); bitsync(); } qunlock(&bit); return n; } error(0, Egreg); return 0; } void bitremove(Chan *c) { error(0, Eperm); } void bitwstat(Chan *c, char *dp) { error(0, Eperm); } void bituserstr(Error *e, char *buf) { consuserstr(e, buf); } void biterrstr(Error *e, char *buf) { rooterrstr(e, buf); }