ref: a141f4c53a32d8227f9a490a8e4f7d87445c47d1
dir: /sys/src/9/omap/dma.c/
/*
* omap3530 system dma controller
*
* terminology: a block consist of frame(s), a frame consist of elements
* (uchar, ushort, or ulong sized).
*/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "../port/error.h"
#include "../port/netif.h"
enum {
Nirq = 4,
Baseirq = 12,
Nchan = 32,
};
/*
* has a sw reset bit
* dma req lines 1, 2, 6, 63 are available for `system expansion'
*/
typedef struct Regs Regs;
typedef struct Dchan Dchan;
struct Regs {
uchar _pad0[8];
/* bitfield of intrs pending, by Dchan; write 1s to clear */
ulong irqsts[Nirq];
ulong irqen[Nirq]; /* bitfield of intrs enabled, by Dchan */
ulong syssts; /* 1<<0 is Resetdone */
ulong syscfg; /* 1<<1 is Softreset */
uchar _pad1[0x64 - 0x30];
ulong caps[5]; /* caps[1] not defined */
ulong gcr; /* knobs */
ulong _pad2;
struct Dchan {
ulong ccr; /* chan ctrl: incr, etc. */
ulong clnkctrl; /* link ctrl */
ulong cicr; /* intr ctrl */
ulong csr; /* status */
ulong csdp; /* src & dest params */
ulong cen; /* element # */
ulong cfn; /* frame # */
ulong cssa; /* src start addr */
ulong cdsa; /* dest start addr */
ulong csei; /* src element index */
ulong csfi; /* src frame index | pkt size */
ulong cdei; /* dest element index */
ulong cdfi; /* dest frame index | pkt size */
ulong csac; /* src addr value (read-only?) */
ulong cdac; /* dest addr value */
ulong ccen; /* curr transferred element # (in frame) */
ulong ccfn; /* curr transferred frame # (in xfer) */
ulong color;
uchar _pad3[24];
} chan[Nchan];
};
enum {
/* cicr/csr bits */
Blocki = 1 << 5,
/* ccr bits */
Enable = 1 << 7,
};
typedef struct Xfer Xfer;
static struct Xfer {
Rendez *rend;
int *done; /* flag to set on intr */
} xfer[Nirq];
int
isdmadone(int irq)
{
Dchan *cp;
Regs *regs = (Regs *)PHYSSDMA;
cp = regs->chan + irq;
return cp->csr & Blocki;
}
static void
dmaintr(Ureg *, void *a)
{
int i = (int)a; /* dma request & chan # */
Dchan *cp;
Regs *regs = (Regs *)PHYSSDMA;
assert(i >= 0 && i < Nirq);
*xfer[i].done = 1;
assert(xfer[i].rend != nil);
wakeup(xfer[i].rend);
cp = regs->chan + i;
if(!(cp->csr & Blocki))
iprint("dmaintr: req %d: Blocki not set; csr %#lux\n",
i, cp->csr);
cp->csr |= cp->csr; /* extinguish intr source */
coherence();
regs->irqsts[i] = regs->irqsts[i]; /* extinguish intr source */
coherence();
regs->irqen[i] &= ~(1 << i);
coherence();
xfer[i].rend = nil;
coherence();
}
void
zerowds(ulong *wdp, int cnt)
{
while (cnt-- > 0)
*wdp++ = 0;
}
static int
istestdmadone(void *arg)
{
return *(int *)arg;
}
void
dmainit(void)
{
int n;
char name[16];
Dchan *cp;
Regs *regs = (Regs *)PHYSSDMA;
if (probeaddr((uintptr)®s->syssts) < 0)
panic("dmainit: no syssts reg");
regs->syssts = 0;
coherence();
regs->syscfg |= 1<<1; /* Softreset */
coherence();
while(!(regs->syssts & (1<<0))) /* Resetdone? */
;
for (n = 0; n < Nchan; n++) {
cp = regs->chan + n;
cp->ccr = 0;
cp->clnkctrl = 0;
cp->cicr = 0;
cp->csr = 0;
cp->csdp = 0;
cp->cen = cp->cfn = 0;
cp->cssa = cp->cdsa = 0;
cp->csei = cp->csfi = 0;
cp->cdei = cp->cdfi = 0;
// cp->csac = cp->cdac = 0; // ro
cp->ccen = cp->ccfn = 0;
cp->color = 0;
}
zerowds((void *)regs->irqsts, sizeof regs->irqsts / sizeof(ulong));
zerowds((void *)regs->irqen, sizeof regs->irqen / sizeof(ulong));
coherence();
regs->gcr = 65; /* burst size + 1 */
coherence();
for (n = 0; n < Nirq; n++) {
snprint(name, sizeof name, "dma%d", n);
intrenable(Baseirq + n, dmaintr, (void *)n, nil, name);
}
}
enum {
Testbyte = 0252,
Testsize = 256,
Scratch = MB,
};
/*
* try to confirm sane operation
*/
void
dmatest(void)
{
int n, done;
uchar *bp;
static ulong pat = 0x87654321;
static Rendez trendez;
if (up == nil)
panic("dmatest: up not set yet");
bp = (uchar *)KADDR(PHYSDRAM + 128*MB);
memset(bp, Testbyte, Scratch);
done = 0;
dmastart((void *)PADDR(bp), Postincr, (void *)PADDR(&pat), Const,
Testsize, &trendez, &done);
sleep(&trendez, istestdmadone, &done);
cachedinvse(bp, Scratch);
if (((ulong *)bp)[0] != pat)
panic("dmainit: copied incorrect data %#lux != %#lux",
((ulong *)bp)[0], pat);
for (n = Testsize; n < Scratch && bp[n] != Testbyte; n++)
;
if (n >= Scratch)
panic("dmainit: ran wild over memory, clobbered ≥%,d bytes", n);
if (bp[n] == Testbyte && n != Testsize)
iprint("dma: %d-byte dma stopped after %d bytes!\n",
Testsize, n);
}
/* addresses are physical */
int
dmastart(void *to, int tmode, void *from, int fmode, uint len, Rendez *rend,
int *done)
{
int irq, chan;
uint ruplen;
Dchan *cp;
Regs *regs = (Regs *)PHYSSDMA;
static Lock alloclck;
/* allocate free irq (and chan) */
ilock(&alloclck);
for (irq = 0; irq < Nirq && xfer[irq].rend != nil; irq++)
;
if (irq >= Nirq)
panic("dmastart: no available irqs; too many concurrent dmas");
chan = irq;
xfer[irq].rend = rend; /* for wakeup at intr time */
xfer[irq].done = done;
*done = 0;
iunlock(&alloclck);
ruplen = ROUNDUP(len, sizeof(ulong));
assert(to != from);
cp = regs->chan + chan;
cp->ccr &= ~Enable; /* paranoia */
cp->cicr = 0;
regs->irqen[irq] &= ~(1 << chan);
coherence();
cp->csdp = 2; /* 2 = log2(sizeof(ulong)) */
cp->cssa = (uintptr)from;
cp->cdsa = (uintptr)to;
cp->ccr = tmode << 14 | fmode << 12;
cp->csei = cp->csfi = cp->cdei = cp->cdfi = 1;
cp->cen = ruplen / sizeof(ulong); /* ulongs / frame */
cp->cfn = 1; /* 1 frame / xfer */
cp->cicr = Blocki; /* intr at end of block */
regs->irqen[irq] |= 1 << chan;
coherence();
cp->ccr |= Enable; /* fire! */
coherence();
return irq;
}