ref: 57f8b3d1acf273a88568c49d0b83b6863485b9e0
dir: /sys/src/9/port/devi2c.c/
/* I²C bus driver */ #include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "../port/i2c.h" enum { Qdir = 0, /* #J */ Qbus, /* #J/bus */ Qctl, /* #J/bus/i2c.n.ctl */ Qdata, /* #J/bus/i2c.n.data */ }; #define TYPE(q) ((ulong)(q).path & 0x0F) #define BUS(q) (((ulong)(q).path>>4) & 0xFF) #define DEV(q) (((ulong)(q).path>>12) & 0xFFF) #define QID(d, b, t) (((d)<<12)|((b)<<4)|(t)) static I2Cbus *buses[16]; static I2Cdev *devs[1024]; static Lock devslock; static void probebus(I2Cbus *bus); void addi2cbus(I2Cbus *bus) { int i; if(bus == nil) return; for(i = 0; i < nelem(buses); i++){ if(buses[i] == nil || buses[i] == bus || strcmp(bus->name, buses[i]->name) == 0){ buses[i] = bus; break; } } } I2Cbus* i2cbus(char *name) { I2Cbus *bus; int i; for(i = 0; i < nelem(buses); i++){ bus = buses[i]; if(bus == nil) break; if(strcmp(bus->name, name) == 0){ probebus(bus); return bus; } } return nil; } void addi2cdev(I2Cdev *dev) { int i; if(dev == nil || dev->bus == nil) return; lock(&devslock); for(i = 0; i < nelem(devs); i++){ if(devs[i] == nil || devs[i] == dev || devs[i]->addr == dev->addr && devs[i]->bus == dev->bus){ devs[i] = dev; unlock(&devslock); return; } } unlock(&devslock); } I2Cdev* i2cdev(I2Cbus *bus, int addr) { I2Cdev *dev; int i; if(bus == nil || addr < 0 || addr >= 1<<10) return nil; lock(&devslock); for(i = 0; i < nelem(devs) && (dev = devs[i]) != nil; i++){ if(dev->addr == addr && dev->bus == bus){ unlock(&devslock); return dev; } } unlock(&devslock); return nil; } static int enterbus(I2Cbus *bus) { if(up != nil && islo()){ eqlock(bus); return 1; } else { while(!canqlock(bus)) ; return 0; } } static void leavebus(I2Cbus *bus) { qunlock(bus); } int i2cbusio(I2Cbus *bus, uchar *pkt, int olen, int ilen) { int user, n; user = enterbus(bus); if(!bus->probed){ leavebus(bus); return -1; } if(user && waserror()){ (*bus->io)(bus, nil, 0, 0); leavebus(bus); nexterror(); } // iprint("%s: <- %.*H\n", bus->name, olen, pkt); n = (*bus->io)(bus, pkt, olen, ilen); // if(n > olen) iprint("%s: -> %.*H\n", bus->name, n - olen, pkt+olen); leavebus(bus); if(user) poperror(); return n; } static int putaddr(I2Cdev *dev, int isread, uchar *pkt, vlong addr) { int n, o = 0; if(dev->a10){ pkt[o++] = 0xF0 | (dev->addr>>(8-1))&6 | (isread != 0); pkt[o++] = dev->addr; } else pkt[o++] = dev->addr<<1 | (isread != 0); if(addr >= 0){ for(n=0; n<dev->subaddr; n++) pkt[o++] = addr >> (n*8); } return o; } int i2csend(I2Cdev *dev, void *data, int len, vlong addr) { uchar pkt[138]; int o; o = putaddr(dev, 0, pkt, addr); if(o+len > sizeof(pkt)) len = sizeof(pkt)-o; if(len > 0) memmove(pkt+o, data, len); return i2cbusio(dev->bus, pkt, o + len, 0) - o; } int i2crecv(I2Cdev *dev, void *data, int len, vlong addr) { uchar pkt[138]; int o; o = putaddr(dev, 1, pkt, addr); if(o+len > sizeof(pkt)) len = sizeof(pkt)-o; len = i2cbusio(dev->bus, pkt, o, len) - o; if(len > 0) memmove(data, pkt+o, len); return len; } int i2cquick(I2Cdev *dev, int rw) { uchar pkt[2]; int o = putaddr(dev, rw, pkt, -1); if(i2cbusio(dev->bus, pkt, o, 0) != o) return -1; return rw != 0; } int i2crecvbyte(I2Cdev *dev) { uchar pkt[2+1]; int o = putaddr(dev, 1, pkt, -1); if(i2cbusio(dev->bus, pkt, o, 1) - o != 1) return -1; return pkt[o]; } int i2csendbyte(I2Cdev *dev, uchar b) { uchar pkt[2+1]; int o = putaddr(dev, 0, pkt, -1); pkt[o] = b; if(i2cbusio(dev->bus, pkt, o+1, 0) - o != 1) return -1; return b; } int i2creadbyte(I2Cdev *dev, ulong addr) { uchar pkt[2+4+1]; int o = putaddr(dev, 1, pkt, addr); if(i2cbusio(dev->bus, pkt, o, 1) - o != 1) return -1; return pkt[o]; } int i2cwritebyte(I2Cdev *dev, ulong addr, uchar b) { uchar pkt[2+4+1]; int o = putaddr(dev, 0, pkt, addr); pkt[o] = b; if(i2cbusio(dev->bus, pkt, o+1, 0) - o != 1) return -1; return b; } int i2creadword(I2Cdev *dev, ulong addr) { uchar pkt[2+4+2]; int o = putaddr(dev, 1, pkt, addr); if(i2cbusio(dev->bus, pkt, o, 2) - o != 2) return -1; return pkt[o] | (ushort)pkt[o+1]<<8; } int i2cwriteword(I2Cdev *dev, ulong addr, ushort w) { uchar pkt[2+4+2]; int o = putaddr(dev, 0, pkt, addr); pkt[o+0] = w; pkt[o+1] = w>>8; if(i2cbusio(dev->bus, pkt, o+2, 0) - o != 2) return -1; return w; } vlong i2cread32(I2Cdev *dev, ulong addr) { uchar pkt[2+4+4]; int o = putaddr(dev, 1, pkt, addr); if(i2cbusio(dev->bus, pkt, o, 4) - o != 4) return -1; return pkt[o] | (ulong)pkt[o+1]<<8 | (ulong)pkt[o+2]<<16 | (ulong)pkt[o+3]<<24; } vlong i2cwrite32(I2Cdev *dev, ulong addr, ulong u) { uchar pkt[2+4+4]; int o = putaddr(dev, 0, pkt, addr); pkt[o+0] = u; pkt[o+1] = u>>8; pkt[o+2] = u>>16; pkt[o+3] = u>>24; if(i2cbusio(dev->bus, pkt, o+4, 0) - o != 4) return -1; return u; } static void probeddev(I2Cdev *dummy) { I2Cdev *dev = smalloc(sizeof(I2Cdev)); memmove(dev, dummy, sizeof(I2Cdev)); addi2cdev(dev); } static void probebus(I2Cbus *bus) { I2Cdev dummy; uchar pkt[2]; int user, n; if(bus->probed) return; user = enterbus(bus); if(bus->probed){ leavebus(bus); return; } if(user && waserror() || (*bus->init)(bus)){ leavebus(bus); if(user) nexterror(); return; } memset(&dummy, 0, sizeof(dummy)); dummy.bus = bus; dummy.a10 = 0; for(dummy.addr = 8; dummy.addr < 0x78; dummy.addr++) { if(i2cdev(bus, dummy.addr) != nil) continue; if(user && waserror()){ (*bus->io)(bus, nil, 0, 0); continue; } n = putaddr(&dummy, 0, pkt, -1); if((*bus->io)(bus, pkt, n, 0) == n) probeddev(&dummy); if(user) poperror(); } dummy.a10 = 1; for(dummy.addr = 0; dummy.addr < (1<<10); dummy.addr++) { if(i2cdev(bus, dummy.addr) != nil) continue; if(user && waserror()){ (*bus->io)(bus, nil, 0, 0); continue; } n = putaddr(&dummy, 0, pkt, -1); if((*bus->io)(bus, pkt, n, 0) == n) probeddev(&dummy); if(user) poperror(); } bus->probed = 1; leavebus(bus); if(user) poperror(); } static int i2cgen(Chan *c, char *, Dirtab*, int, int s, Dir *dp) { I2Cbus *bus; I2Cdev *dev; Qid q; switch(TYPE(c->qid)){ case Qdir: if(s == DEVDOTDOT){ Gendir: mkqid(&q, QID(0, 0, Qdir), 0, QTDIR); snprint(up->genbuf, sizeof up->genbuf, "#J"); devdir(c, q, up->genbuf, 0, eve, 0500, dp); return 1; } if(s >= nelem(buses)) return -1; bus = buses[s]; if(bus == nil) return -1; mkqid(&q, QID(0, s, Qbus), 0, QTDIR); devdir(c, q, bus->name, 0, eve, 0500, dp); return 1; case Qbus: if(s == DEVDOTDOT) goto Gendir; if((s/2) >= nelem(devs)) return -1; bus = buses[BUS(c->qid)]; probebus(bus); lock(&devslock); dev = devs[s/2]; unlock(&devslock); if(dev == nil) return -1; if(dev->bus != bus) return 0; if(s & 1){ mkqid(&q, QID(dev->addr, BUS(c->qid), Qdata), 0, 0); goto Gendata; } mkqid(&q, QID(dev->addr, BUS(c->qid), Qctl), 0, 0); goto Genctl; case Qctl: q = c->qid; Genctl: snprint(up->genbuf, sizeof up->genbuf, "i2c.%lux.ctl", DEV(q)); devdir(c, q, up->genbuf, 0, eve, 0600, dp); return 1; case Qdata: q = c->qid; bus = buses[BUS(q)]; dev = i2cdev(bus, DEV(q)); if(dev == nil) return -1; Gendata: snprint(up->genbuf, sizeof up->genbuf, "i2c.%lux.data", DEV(q)); devdir(c, q, up->genbuf, dev->size, eve, 0600, dp); return 1; } return -1; } static Chan* i2cattach(char *spec) { return devattach('J', spec); } static Chan* i2copen(Chan *c, int mode) { c = devopen(c, mode, nil, 0, i2cgen); switch(TYPE(c->qid)){ case Qctl: case Qdata: c->aux = i2cdev(buses[BUS(c->qid)], DEV(c->qid)); if(c->aux == nil) error(Enonexist); break; } return c; } enum { CMsize, CMsubaddress, }; static Cmdtab i2cctlmsg[] = { CMsize, "size", 2, CMsubaddress, "subaddress", 2, }; static long i2cwrctl(I2Cdev *dev, void *data, long len) { Cmdbuf *cb; Cmdtab *ct; ulong u; cb = parsecmd(data, len); if(waserror()){ free(cb); nexterror(); } ct = lookupcmd(cb, i2cctlmsg, nelem(i2cctlmsg)); switch(ct->index){ case CMsize: dev->size = strtoul(cb->f[1], nil, 0); break; case CMsubaddress: u = strtoul(cb->f[1], nil, 0); if(u > 4) cmderror(cb, Ebadarg); dev->subaddr = u; break; default: cmderror(cb, Ebadarg); } free(cb); poperror(); return len; } static long i2crdctl(I2Cdev *dev, void *data, long len, vlong offset) { char cfg[64]; snprint(cfg, sizeof(cfg), "size %lud\nsubaddress %d\n", dev->size, dev->subaddr); return readstr((ulong)offset, data, len, cfg); } static long i2cwrite(Chan *c, void *data, long len, vlong offset) { I2Cdev *dev; switch(TYPE(c->qid)){ default: error(Egreg); return -1; case Qctl: dev = c->aux; return i2cwrctl(dev, data, len); case Qdata: break; } dev = c->aux; if(dev->size){ if(offset+len > dev->size){ if(offset >= dev->size) return 0; len = dev->size - offset; } } len = i2csend(dev, data, len, offset); if(len < 0) error(Eio); return len; } static long i2cread(Chan *c, void *data, long len, vlong offset) { I2Cdev *dev; if(c->qid.type == QTDIR) return devdirread(c, data, len, nil, 0, i2cgen); switch(TYPE(c->qid)){ default: error(Egreg); case Qctl: dev = c->aux; return i2crdctl(dev, data, len, offset); case Qdata: break; } dev = c->aux; if(dev->size){ if(offset+len > dev->size){ if(offset >= dev->size) return 0; len = dev->size - offset; } } len = i2crecv(dev, data, len, offset); if(len < 0) error(Eio); return len; } void i2cclose(Chan*) { } static Walkqid* i2cwalk(Chan *c, Chan *nc, char **name, int nname) { return devwalk(c, nc, name, nname, nil, 0, i2cgen); } static int i2cstat(Chan *c, uchar *dp, int n) { return devstat(c, dp, n, nil, 0, i2cgen); } Dev i2cdevtab = { 'J', "i2c", devreset, devinit, devshutdown, i2cattach, i2cwalk, i2cstat, i2copen, devcreate, i2cclose, i2cread, devbread, i2cwrite, devbwrite, devremove, devwstat, devpower, };