ref: eb687adecd365876d6b6918a9ee4f8e8e7f205f6
parent: 88c998b2650d684086faca8e65f9b2f67c764b47
author: Matthew Veety <[email protected]>
date: Fri May 16 06:56:23 EDT 2014
added devgpio (thanks Krystian!). Also added getrevision() to vcore which allows you to get the raspberry pi board revision. I kept in the segment that allows direct access to the gpio memory
--- /dev/null
+++ b/sys/src/9/bcm/devgpio.c
@@ -1,0 +1,746 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "../port/error.h"
+#include "io.h"
+
+// path:
+// 3 bits - generic file type (Qinctl, Qindata)
+// 3 bits - parent type
+// 3 bits - chosen scheme type (Qgeneric, Qbcm, Qboard, Qwpi)
+// 6 bits - input number
+
+#define PIN_TABLE_SIZE 32
+
+#define PIN_OFFSET SCHEME_OFFSET + SCHEME_BITS
+#define PIN_BITS 6
+#define PIN_MASK ((1 << PIN_BITS) - 1)
+#define PIN_NUMBER(q) (((q).path >> PIN_OFFSET) & PIN_MASK)
+
+#define SCHEME_OFFSET PARENT_OFFSET + PARENT_BITS
+#define SCHEME_BITS 3
+#define SCHEME_MASK ((1 << SCHEME_BITS) - 1)
+#define SCHEME_TYPE(q) (((q).path >> SCHEME_OFFSET) & SCHEME_MASK)
+
+#define PARENT_OFFSET FILE_OFFSET + FILE_BITS
+#define PARENT_BITS 3
+#define PARENT_MASK ((1 << PARENT_BITS) - 1)
+#define PARENT_TYPE(q) (((q).path >> PARENT_OFFSET) & PARENT_MASK)
+
+#define FILE_OFFSET 0
+#define FILE_BITS 3
+#define FILE_MASK ((1 << FILE_BITS) - 1)
+#define FILE_TYPE(q) (((q).path >> FILE_OFFSET) & FILE_MASK)
+
+// pin is valid only when file is Qdata otherwise 0 is used
+#define PATH(pin, scheme, parent, file) \
+ ((pin & PIN_MASK) << PIN_OFFSET) \
+ | ((scheme & SCHEME_MASK) << SCHEME_OFFSET) \
+ | ((parent & PARENT_MASK) << PARENT_OFFSET) \
+ | ((file & FILE_MASK) << FILE_OFFSET)
+
+#define SET_BIT(f, offset, value) \
+ (*f = ((*f & ~(1 << (offset % 32))) | (value << (offset % 32))))
+
+static int dflag = 0;
+#define D(...) if(dflag) print(__VA_ARGS__)
+
+enum {+ // parent types
+ Qtopdir = 0,
+ Qgpiodir,
+ // file types
+ Qdir,
+ Qdata,
+ Qctl,
+ Qevent,
+};
+enum {+ // naming schemes
+ Qbcm,
+ Qboard,
+ Qwpi,
+ Qgeneric
+};
+
+
+// commands
+enum {+ CMzero,
+ CMone,
+ CMscheme,
+ CMfunc,
+ CMpull,
+ CMevent,
+};
+
+// dev entries
+Dirtab topdir = { "#G", {PATH(0, Qgeneric, Qtopdir, Qdir), 0, QTDIR}, 0, 0555 };+Dirtab gpiodir = { "gpio", {PATH(0, Qgeneric, Qgpiodir, Qdir), 0, QTDIR}, 0, 0555 };+
+Dirtab typedir[] = {+ "OK", { PATH(16, Qgeneric, Qgpiodir, Qdata), 0, QTFILE }, 0, 0666,+ "ctl", { PATH(0, Qgeneric, Qgpiodir, Qctl), 0, QTFILE }, 0, 0666,+ "event", { PATH(0, Qgeneric, Qgpiodir, Qevent), 0, QTFILE }, 0, 0444,+};
+
+// commands definition
+static
+Cmdtab gpiocmd[] = {+ CMzero, "0", 1,
+ CMone, "1", 1,
+ CMscheme, "scheme", 2,
+ CMfunc, "function", 3,
+ CMpull, "pull", 3,
+ CMevent, "event", 4,
+};
+
+static int pinscheme;
+static int boardrev;
+
+static Rendez rend;
+static u32int eventvalue;
+static long eventinuse;
+static Lock eventlock;
+
+//
+// BCM
+//
+enum {+ Fin = 0,
+ Fout,
+ Ffunc5,
+ Ffunc4,
+ Ffunc0,
+ Ffunc1,
+ Ffunc2,
+ Ffunc3,
+};
+
+static char *funcname[] = {+ "in", "out", "5", "4", "0", "1", "2", "3",
+};
+
+enum {+ Poff = 0,
+ Pdown,
+ Pup,
+};
+
+static char *pudname[] = {+ "off", "down", "up",
+};
+
+static char *evstatename[] = {+ "disable", "enable",
+};
+
+enum {+ Erising,
+ Efalling,
+};
+
+static char *evtypename[] = {+ "edge-rising", "edge-falling",
+};
+
+static char *bcmtableR1[PIN_TABLE_SIZE] = {+ "1", "2", 0, 0, // 0-3
+ "4", 0, 0, "7", // 4-7
+ "8", "9", "10", "11", // 8-11
+ 0, 0, "14", "15", // 12-15
+ 0, "17", "18", 0, // 16-19
+ 0, "21", "22", "23", // 20-23
+ "24", "25", 0, 0, // 24-27
+ 0, 0, 0, 0, // 28-31
+};
+
+static char *bcmtableR2[PIN_TABLE_SIZE] = {+ 0, 0, "2", "3", // 0-3
+ "4", 0, 0, "7", // 4-7
+ "8", "9", "10", "11", // 8-11
+ 0, 0, "14", "15", // 12-15
+ 0, "17", "18", 0, // 16-19
+ 0, 0, "22", "23", // 20-23
+ "24", "25", 0, "27", // 24-27
+ "28", "29", "30", "31", // 28-31
+};
+
+static char *boardtableR1[PIN_TABLE_SIZE] = {+ "SDA", "SCL", 0, 0, // 0-3
+ "GPIO7", 0, 0, "CE1", // 4-7
+ "CE0", "MISO", "MOSI", "SCLK", // 8-11
+ 0, 0, "TxD", "RxD", // 12-15
+ 0, "GPIO0", "GPIO1", 0, // 16-19
+ 0, "GPIO2", "GPIO3", "GPIO4", // 20-23
+ "GPIO5", "GPIO6", 0, 0, // 24-27
+ 0, 0, 0, 0, // 28-31
+};
+
+static char *boardtableR2[PIN_TABLE_SIZE] = {+ 0, 0, "SDA", "SCL", // 0-3
+ "GPIO7", 0, 0, "CE1", // 4-7
+ "CE0", "MISO", "MOSI", "SCLK", // 8-11
+ 0, 0, "TxD", "RxD", // 12-15
+ 0, "GPIO0", "GPIO1", 0, // 16-19
+ 0, 0, "GPIO3", "GPIO4", // 20-23
+ "GPIO5", "GPIO6", 0, "GPIO2", // 24-27
+ "GPIO8", "GPIO9", "GPIO10", "GPIO11", // 28-31
+};
+
+static char *wpitableR1[PIN_TABLE_SIZE] = {+ "8", "9", 0, 0, // 0-3
+ "7", 0, 0, "11", // 4-7
+ "10", "13", "12", "14", // 8-11
+ 0, 0, "15", "16", // 12-15
+ 0, "0", "1", 0, // 16-19
+ 0, "2", "3", "4", // 20-23
+ "5", "6", 0, 0, // 24-27
+ 0, 0, 0, 0, // 28-31
+};
+
+static char *wpitableR2[PIN_TABLE_SIZE] = {+ 0, 0, "8", "9", // 0-3
+ "7", 0, 0, "11", // 4-7
+ "10", "13", "12", "14", // 8-11
+ 0, 0, "15", "16", // 12-15
+ 0, "0", "1", 0, // 16-19
+ 0, 0, "3", "4", // 20-23
+ "5", "6", 0, "2", // 24-27
+ "17", "18", "19", "20", // 28-31
+};
+
+static char *schemename[] = {+ "bcm", "board", "wpi",
+};
+
+static char**
+getpintable(void)
+{+ switch(pinscheme)
+ {+ case Qbcm:
+ return (boardrev>3)?bcmtableR2:bcmtableR1;
+ case Qboard:
+ return (boardrev>3)?boardtableR2:boardtableR1;
+ case Qwpi:
+ return (boardrev>3)?wpitableR2:wpitableR1;
+ default:
+ return nil;
+ }
+}
+
+// stolen from uartmini.c
+#define GPIOREGS (VIRTIO+0x200000)
+/* GPIO regs */
+enum {+ Fsel0 = 0x00>>2,
+ FuncMask= 0x7,
+ Set0 = 0x1c>>2,
+ Clr0 = 0x28>>2,
+ Lev0 = 0x34>>2,
+ Evds0 = 0x40>>2,
+ Redge0 = 0x4C>>2,
+ Fedge0 = 0x58>>2,
+ Hpin0 = 0x64>>2,
+ Lpin0 = 0x70>>2,
+ ARedge0 = 0x7C>>2,
+ AFedge0 = 0x88>2,
+ PUD = 0x94>>2,
+ PUDclk0 = 0x98>>2,
+ PUDclk1 = 0x9c>>2,
+};
+
+static void
+gpiofuncset(uint pin, int func)
+{ + u32int *gp, *fsel;
+ int off;
+
+ gp = (u32int*)GPIOREGS;
+ fsel = &gp[Fsel0 + pin/10];
+ off = (pin % 10) * 3;
+ *fsel = (*fsel & ~(FuncMask<<off)) | func<<off;
+}
+
+static int
+gpiofuncget(uint pin)
+{ + u32int *gp, *fsel;
+ int off;
+
+ gp = (u32int*)GPIOREGS;
+ fsel = &gp[Fsel0 + pin/10];
+ off = (pin % 10) * 3;
+ return ((*fsel >> off) & FuncMask);
+}
+
+static void
+gpiopullset(uint pin, int state)
+{+ u32int *gp, *reg;
+ u32int mask;
+
+ gp = (u32int*)GPIOREGS;
+ reg = &gp[PUDclk0 + pin/32];
+ mask = 1 << (pin % 32);
+ gp[PUD] = state;
+ microdelay(1);
+ *reg = mask;
+ microdelay(1);
+ *reg = 0;
+}
+
+static void
+gpioout(uint pin, int set)
+{+ u32int *gp;
+ int v;
+
+ gp = (u32int*)GPIOREGS;
+ v = set? Set0 : Clr0;
+ gp[v + pin/32] = 1 << (pin % 32);
+}
+
+static int
+gpioin(uint pin)
+{+ u32int *gp;
+
+ gp = (u32int*)GPIOREGS;
+ return (gp[Lev0 + pin/32] & (1 << (pin % 32))) != 0;
+}
+
+static void
+gpioevent(uint pin, int event, int enable)
+{+ u32int *gp, *field;
+ int reg = 0;
+
+ switch(event)
+ {+ case Erising:
+ reg = Redge0;
+ break;
+ case Efalling:
+ reg = Fedge0;
+ break;
+ default:
+ panic("gpio: unknown event type");+ }
+ gp = (u32int*)GPIOREGS;
+ field = &gp[reg + pin/32];
+ SET_BIT(field, pin, enable);
+}
+
+static void
+mkdeventry(Chan *c, Qid qid, Dirtab *tab, Dir *db)
+{+ mkqid(&qid, tab->qid.path, tab->qid.vers, tab->qid.type);
+ devdir(c, qid, tab->name, tab->length, eve, tab->perm, db);
+}
+
+static int
+gpiogen(Chan *c, char *, Dirtab *, int , int s, Dir *db)
+{+ Qid qid;
+ int parent, scheme, l;
+ char **pintable = getpintable();
+
+ qid.vers = 0;
+ parent = PARENT_TYPE(c->qid);
+ scheme = SCHEME_TYPE(c->qid);
+
+ if(s == DEVDOTDOT)
+ {+ switch(parent)
+ {+ case Qtopdir:
+ case Qgpiodir:
+ mkdeventry(c, qid, &topdir, db);
+ break;
+ default:
+ return -1;
+ }
+ return 1;
+ }
+
+ if(parent == Qtopdir)
+ {+ switch(s)
+ {+ case 0:
+ mkdeventry(c, qid, &gpiodir, db);
+ break;
+ default:
+ return -1;
+ }
+ return 1;
+ }
+
+ if(scheme != Qgeneric && scheme != pinscheme)
+ {+ error(nil);
+ }
+
+ if(parent == Qgpiodir)
+ {+ l = nelem(typedir);
+ if(s < l)
+ {+ mkdeventry(c, qid, &typedir[s], db);
+ } else if (s < l + PIN_TABLE_SIZE)
+ {+ s -= l;
+
+ if(pintable[s] == 0)
+ {+ return 0;
+ }
+ mkqid(&qid, PATH(s, pinscheme, Qgpiodir, Qdata), 0, QTFILE);
+ snprint(up->genbuf, sizeof up->genbuf, "%s", pintable[s]);
+ devdir(c, qid, up->genbuf, 0, eve, 0666, db);
+ }
+ else
+ {+ return -1;
+ }
+ return 1;
+ }
+
+ return 1;
+}
+
+static void
+interrupt(Ureg*, void *)
+{+
+ u32int *gp, *field;
+ char pin;
+
+ gp = (u32int*)GPIOREGS;
+
+ int set;
+
+ coherence();
+
+ eventvalue = 0;
+
+ for(pin = 0; pin < PIN_TABLE_SIZE; pin++)
+ {+ set = (gp[Evds0 + pin/32] & (1 << (pin % 32))) != 0;
+
+ if(set)
+ {+ field = &gp[Evds0 + pin/32];
+ SET_BIT(field, pin, 1);
+ SET_BIT(&eventvalue, pin, 1);
+ }
+ }
+ coherence();
+
+ wakeup(&rend);
+}
+
+static void
+gpioinit(void)
+{+ boardrev = getrevision() & 0xff;
+ pinscheme = Qboard;
+ intrenable(49, interrupt, nil, 0, "gpio1");
+}
+
+static void
+gpioshutdown(void)
+{ }+
+static Chan*
+gpioattach(char *spec)
+{+ return devattach('G', spec);+}
+
+static Walkqid*
+gpiowalk(Chan *c, Chan *nc, char** name, int nname)
+{+ return devwalk(c, nc, name, nname, 0, 0, gpiogen);
+}
+
+static int
+gpiostat(Chan *c, uchar *db, int n)
+{+ return devstat(c, db, n, 0, 0, gpiogen);
+}
+
+static Chan*
+gpioopen(Chan *c, int omode)
+{+ int type;
+
+ c = devopen(c, omode, 0, 0, gpiogen);
+
+ type = FILE_TYPE(c->qid);
+
+ switch(type)
+ {+ case Qdata:
+ c->iounit = 1;
+ break;
+ case Qctl:
+ break;
+ case Qevent:
+ lock(&eventlock);
+ if(eventinuse != 0){+ c->flag &= ~COPEN;
+ unlock(&eventlock);
+ error(Einuse);
+ }
+ eventinuse = 1;
+ unlock(&eventlock);
+ eventvalue = 0;
+ c->iounit = 4;
+ }
+
+ return c;
+}
+
+static void
+gpioclose(Chan *c)
+{+ int type;
+ type = FILE_TYPE(c->qid);
+
+ switch(type)
+ {+ case Qevent:
+ if(c->flag & COPEN)
+ {+ if(c->flag & COPEN){+ eventinuse = 0;
+ }
+ }
+ break;
+ }
+}
+
+static int
+isset(void *)
+{+ return eventvalue;
+}
+
+static long
+gpioread(Chan *c, void *va, long n, vlong off)
+{+ int type, scheme;
+ uint pin;
+ char *a;
+
+ a = va;
+
+ if(c->qid.type & QTDIR)
+ {+ return devdirread(c, va, n, 0, 0, gpiogen);
+ }
+
+ type = FILE_TYPE(c->qid);
+ scheme = SCHEME_TYPE(c->qid);
+
+ if(scheme != Qgeneric && scheme != pinscheme)
+ {+ error(nil);
+ }
+
+ switch(type)
+ {+ case Qdata:
+ pin = PIN_NUMBER(c->qid);
+ a[0] = (gpioin(pin))?'1':'0';
+ n = 1;
+ break;
+ case Qctl:
+ break;
+ case Qevent:
+ if(off >= 4)
+ {+ off %= 4;
+ eventvalue = 0;
+ }
+ sleep(&rend, isset, 0);
+
+ if(off + n > 4)
+ {+ n = 4 - off;
+ }
+ memmove(a, &eventvalue + off, n);
+ }
+
+ return n;
+}
+
+static int
+getpin(char *pinname)
+{+ int i;
+ char **pintable = getpintable();
+ for(i = 0; i < PIN_TABLE_SIZE; i++)
+ {+ if(!pintable[i])
+ {+ continue;
+ }
+ if(strncmp(pintable[i], pinname, strlen(pintable[i])) == 0)
+ {+ return i;
+ }
+ }
+ return -1;
+}
+
+static long
+gpiowrite(Chan *c, void *va, long n, vlong)
+{+ int type, i, scheme;
+ uint pin;
+ char *arg;
+
+ Cmdbuf *cb;
+ Cmdtab *ct;
+
+ if(c->qid.type & QTDIR)
+ {+ error(Eisdir);
+ }
+
+ type = FILE_TYPE(c->qid);
+
+ scheme = SCHEME_TYPE(c->qid);
+
+ if(scheme != Qgeneric && scheme != pinscheme)
+ {+ error(nil);
+ }
+
+ cb = parsecmd(va, n);
+ if(waserror())
+ {+ free(cb);
+ nexterror();
+ }
+ ct = lookupcmd(cb, gpiocmd, nelem(gpiocmd));
+ if(ct == nil)
+ {+ error(Ebadctl);
+ }
+
+ switch(type)
+ {+ case Qdata:
+ pin = PIN_NUMBER(c->qid);
+
+ switch(ct->index)
+ {+ case CMzero:
+ gpioout(pin, 0);
+ break;
+ case CMone:
+ gpioout(pin, 1);
+ break;
+ default:
+ error(Ebadctl);
+ }
+ break;
+ case Qctl:
+ switch(ct->index)
+ {+ case CMscheme:
+ arg = cb->f[1];
+ for(i = 0; i < nelem(schemename); i++)
+ {+ if(strncmp(schemename[i], arg, strlen(schemename[i])) == 0)
+ {+ pinscheme = i;
+ break;
+ }
+ }
+ break;
+ case CMfunc:
+ pin = getpin(cb->f[2]);
+ arg = cb->f[1];
+ if(pin == -1) {+ error(Ebadctl);
+ }
+ for(i = 0; i < nelem(funcname); i++)
+ {+ if(strncmp(funcname[i], arg, strlen(funcname[i])) == 0)
+ {+ gpiofuncset(pin, i);
+ break;
+ }
+ }
+ break;
+ case CMpull:
+ pin = getpin(cb->f[2]);
+ if(pin == -1) {+ error(Ebadctl);
+ }
+ arg = cb->f[1];
+ for(i = 0; i < nelem(pudname); i++)
+ {+ if(strncmp(pudname[i], arg, strlen(pudname[i])) == 0)
+ {+ gpiopullset(pin, i);
+ break;
+ }
+ }
+ break;
+ case CMevent:
+ pin = getpin(cb->f[3]);
+ if(pin == -1) {+ error(Ebadctl);
+ }
+
+ arg = cb->f[1];
+ for(i = 0; i < nelem(evtypename); i++)
+ {+ if(strncmp(evtypename[i], arg, strlen(evtypename[i])) == 0)
+ {+ gpioevent(pin, i, (cb->f[2][0] == 'e'));
+ break;
+ }
+ }
+ break;
+ default:
+ error(Ebadctl);
+ }
+ break;
+ }
+
+ free(cb);
+
+ poperror();
+ return n;
+}
+
+Dev gpiodevtab = {+ 'G',
+ "gpio",
+
+ devreset,
+ gpioinit,
+ gpioshutdown,
+ gpioattach,
+ gpiowalk,
+ gpiostat,
+ gpioopen,
+ devcreate,
+ gpioclose,
+ gpioread,
+ devbread,
+ gpiowrite,
+ devbwrite,
+ devremove,
+ devwstat,
+};
--- a/sys/src/9/bcm/fns.h
+++ b/sys/src/9/bcm/fns.h
@@ -72,6 +72,7 @@
extern void vectors(void);
extern void vtable(void);
extern uint gettemp(int);
+extern uint getrevision(void);
/*
* floating point emulation
--- a/sys/src/9/bcm/pif
+++ b/sys/src/9/bcm/pif
@@ -17,7 +17,7 @@
draw screen swcursor
mouse mouse
uart
-
+ gpio
sd
usb
--- a/sys/src/9/bcm/vcore.c
+++ b/sys/src/9/bcm/vcore.c
@@ -33,6 +33,7 @@
TagResp = 1<<31,
TagGetfwrev = 0x00000001,
+ TagGetbrdrev = 0x00010002,
TagGetmac = 0x00010003,
TagGetram = 0x00010005,
TagGetpower = 0x00020001,
@@ -257,6 +258,15 @@
u32int buf[1];
if(vcreq(TagGetfwrev, buf, 0, sizeof buf) != sizeof buf)
+ return 0;
+ return buf[0];
+}
+
+uint
+getrevision(void)
+{+ u32int buf[1];
+ if(vcreq(TagGetbrdrev, buf, 0, sizeof buf) != sizeof buf)
return 0;
return buf[0];
}