ref: 457ba087b13a881b013940f6e54c09566ec10ed1
dir: /sys/src/9/bcm/emmc.c/
/*
* bcm2835 external mass media controller (mmc / sd host interface)
*
* Copyright © 2012 Richard Miller <r.miller@acm.org>
*/
/*
Not officially documented: emmc can be connected to different gpio pins
48-53 (SD card)
22-27 (P1 header)
34-39 (wifi - pi3 only)
using ALT3 function to activate the required routing
*/
#include "u.h"
#include "../port/lib.h"
#include "../port/error.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "../port/sd.h"
#define EMMCREGS (VIRTIO+0x300000)
enum {
Extfreq = 100*Mhz, /* guess external clock frequency if */
/* not available from vcore */
};
enum {
/* Controller registers */
Arg2 = 0x00>>2,
Blksizecnt = 0x04>>2,
Arg1 = 0x08>>2,
Cmdtm = 0x0c>>2,
Resp0 = 0x10>>2,
Resp1 = 0x14>>2,
Resp2 = 0x18>>2,
Resp3 = 0x1c>>2,
Data = 0x20>>2,
Status = 0x24>>2,
Control0 = 0x28>>2,
Control1 = 0x2c>>2,
Interrupt = 0x30>>2,
Irptmask = 0x34>>2,
Irpten = 0x38>>2,
Control2 = 0x3c>>2,
Forceirpt = 0x50>>2,
Boottimeout = 0x70>>2,
Dbgsel = 0x74>>2,
Exrdfifocfg = 0x80>>2,
Exrdfifoen = 0x84>>2,
Tunestep = 0x88>>2,
Tunestepsstd = 0x8c>>2,
Tunestepsddr = 0x90>>2,
Spiintspt = 0xf0>>2,
Slotisrver = 0xfc>>2,
/* Control0 */
Hispeed = 1<<2,
Dwidth4 = 1<<1,
Dwidth1 = 0<<1,
DwidthMask = Dwidth4,
/* Control1 */
Srstdata = 1<<26, /* reset data circuit */
Srstcmd = 1<<25, /* reset command circuit */
Srsthc = 1<<24, /* reset complete host controller */
Datatoshift = 16, /* data timeout unit exponent */
DTO = 14, /* data timeout exponent (guesswork) */
Datatomask = 0xF0000,
Clkfreq8shift = 8, /* SD clock base divider LSBs */
Clkfreq8mask = 0xFF00,
Clkfreqms2shift = 6, /* SD clock base divider MSBs */
Clkfreqms2mask = 0xC0,
Clkgendiv = 0<<5, /* SD clock divided */
Clkgenprog = 1<<5, /* SD clock programmable */
Clken = 1<<2, /* SD clock enable */
Clkstable = 1<<1,
Clkintlen = 1<<0, /* enable internal EMMC clocks */
/* Cmdtm */
Indexshift = 24,
Suspend = 1<<22,
Resume = 2<<22,
Abort = 3<<22,
Isdata = 1<<21,
Ixchken = 1<<20,
Crcchken = 1<<19,
Respmask = 3<<16,
Respnone = 0<<16,
Resp136 = 1<<16,
Resp48 = 2<<16,
Resp48busy = 3<<16,
Multiblock = 1<<5,
Host2card = 0<<4,
Card2host = 1<<4,
Autocmd12 = 1<<2,
Autocmd23 = 2<<2,
Blkcnten = 1<<1,
/* Interrupt */
Acmderr = 1<<24,
Denderr = 1<<22,
Dcrcerr = 1<<21,
Dtoerr = 1<<20,
Cbaderr = 1<<19,
Cenderr = 1<<18,
Ccrcerr = 1<<17,
Ctoerr = 1<<16,
Err = 1<<15,
Cardintr = 1<<8, /* not in Broadcom datasheet */
Cardinsert = 1<<6, /* not in Broadcom datasheet */
Readrdy = 1<<5,
Writerdy = 1<<4,
Datadone = 1<<1,
Cmddone = 1<<0,
/* Status */
Bufread = 1<<11, /* not in Broadcom datasheet */
Bufwrite = 1<<10, /* not in Broadcom datasheet */
Readtrans = 1<<9,
Writetrans = 1<<8,
Datactive = 1<<2,
Datinhibit = 1<<1,
Cmdinhibit = 1<<0,
};
typedef struct Ctlr Ctlr;
struct Ctlr {
Rendez r;
int fastclock;
ulong extclk;
};
static Ctlr emmc;
static void emmcinterrupt(Ureg*, void*);
static void
WR(int reg, u32int val)
{
u32int *r = (u32int*)EMMCREGS;
if(0)print("WR %2.2ux %ux\n", reg<<2, val);
microdelay(emmc.fastclock ? 2: 20);
coherence();
r[reg] = val;
}
static uint
clkdiv(uint d)
{
uint v;
assert(d < 1<<10);
v = (d << Clkfreq8shift) & Clkfreq8mask;
v |= ((d >> 8) << Clkfreqms2shift) & Clkfreqms2mask;
return v;
}
static void
emmcclk(uint freq)
{
u32int *r = (u32int*)EMMCREGS;
uint div;
int i;
div = emmc.extclk / (freq<<1);
if(emmc.extclk / (div<<1) > freq)
div++;
WR(Control1, clkdiv(div) |
DTO<<Datatoshift | Clkgendiv | Clken | Clkintlen);
emmc.fastclock = freq > 400000;
for(i = 0; i < 1000; i++){
delay(1);
if(r[Control1] & Clkstable)
break;
}
if(i == 1000)
print("emmc: can't set clock to %ud\n", freq);
}
static void
emmcbus(SDio*, int width, int speed)
{
u32int *r = (u32int*)EMMCREGS;
switch(width){
case 1:
WR(Control0, (r[Control0] & ~DwidthMask) | Dwidth1);
break;
case 4:
WR(Control0, (r[Control0] & ~DwidthMask) | Dwidth4);
break;
}
if(speed)
emmcclk(speed);
}
static int
datadone(void*)
{
u32int *r = (u32int*)EMMCREGS;
int i;
i = r[Interrupt];
return i & (Datadone|Err);
}
static int
cardintready(void*)
{
u32int *r = (u32int*)EMMCREGS;
int i;
i = r[Interrupt];
return i & Cardintr;
}
static int
emmcinit(SDio*)
{
u32int *r = (u32int*)EMMCREGS;
ulong clk;
clk = getclkrate(ClkEmmc);
if(clk == 0){
clk = Extfreq;
print("emmc: assuming external clock %lud Mhz\n", clk/1000000);
}
emmc.extclk = clk;
if(0)print("emmc control %8.8ux %8.8ux %8.8ux\n",
r[Control0], r[Control1], r[Control2]);
WR(Control1, Srsthc);
delay(10);
while(r[Control1] & Srsthc)
;
WR(Control1, Srstdata);
delay(10);
WR(Control1, 0);
return 0;
}
static int
emmcinquiry(SDio*, char *inquiry, int inqlen)
{
u32int *r = (u32int*)EMMCREGS;
uint ver;
ver = r[Slotisrver] >> 16;
return snprint(inquiry, inqlen,
"Arasan eMMC SD Host Controller %2.2x Version %2.2x",
ver&0xFF, ver>>8);
}
static void
emmcenable(SDio *io)
{
emmcclk(400000);
WR(Irpten, 0);
WR(Irptmask, ~0);
WR(Interrupt, ~0);
intrenable(IRQmmc, emmcinterrupt, nil, BUSUNKNOWN, io->name);
}
static int
emmccmd(SDio*, SDiocmd *cmd, u32int arg, u32int *resp)
{
u32int *r = (u32int*)EMMCREGS;
u32int c;
int i;
ulong now;
c = (u32int)cmd->index << Indexshift;
switch(cmd->resp){
case 0:
c |= Respnone;
break;
case 1:
if(cmd->busy){
c |= Resp48busy | Ixchken | Crcchken;
break;
}
default:
c |= Resp48 | Ixchken | Crcchken;
break;
case 2:
c |= Resp136 | Crcchken;
break;
case 3:
c |= Resp48;
break;
}
if(cmd->data){
if(cmd->data & 1)
c |= Isdata | Card2host;
else
c |= Isdata | Host2card;
if(cmd->data > 2)
c |= Multiblock | Blkcnten;
}
if((r[Status] & Datinhibit) &&
((c & Isdata) || (c & Respmask) == Resp48busy)){
print("emmccmd: need to reset Cmdinhibit intr %ux stat %ux\n",
r[Interrupt], r[Status]);
WR(Control1, r[Control1] | Srstcmd);
while(r[Control1] & Srstcmd)
;
while(r[Status] & Cmdinhibit)
;
}
if((c & Isdata || (c & Respmask) == Resp48busy) &&
r[Status] & Datinhibit){
print("emmccmd: need to reset Datinhibit intr %ux stat %ux\n",
r[Interrupt], r[Status]);
WR(Control1, r[Control1] | Srstdata);
while(r[Control1] & Srstdata)
;
while(r[Status] & Datinhibit)
;
}
WR(Arg1, arg);
if((i = (r[Interrupt] & ~Cardintr)) != 0){
if(i != Cardinsert)
print("emmc: before command, intr was %ux\n", i);
WR(Interrupt, i);
}
WR(Cmdtm, c);
now = MACHP(0)->ticks;
while(((i=r[Interrupt])&(Cmddone|Err)) == 0)
if(MACHP(0)->ticks - now > HZ)
break;
if((i&(Cmddone|Err)) != Cmddone){
if((i&~(Err|Cardintr)) != Ctoerr)
print("emmc: %s cmd %ux arg %ux error intr %ux stat %ux\n",
cmd->name, c, arg, i, r[Status]);
WR(Interrupt, i);
if(r[Status]&Cmdinhibit){
WR(Control1, r[Control1]|Srstcmd);
while(r[Control1]&Srstcmd)
;
}
error(Eio);
}
WR(Interrupt, i & ~(Datadone|Readrdy|Writerdy));
switch(c & Respmask){
case Resp136:
resp[0] = r[Resp0]<<8;
resp[1] = r[Resp0]>>24 | r[Resp1]<<8;
resp[2] = r[Resp1]>>24 | r[Resp2]<<8;
resp[3] = r[Resp2]>>24 | r[Resp3]<<8;
break;
case Resp48:
case Resp48busy:
resp[0] = r[Resp0];
break;
case Respnone:
resp[0] = 0;
break;
}
if((c & Respmask) == Resp48busy){
WR(Irpten, r[Irpten]|Datadone|Err);
tsleep(&emmc.r, datadone, 0, 3000);
i = r[Interrupt];
if((i & Datadone) == 0)
print("emmcio: no Datadone after %s\n", cmd->name);
if(i & Err)
print("emmcio: %s error interrupt %ux\n",
cmd->name, r[Interrupt]);
WR(Interrupt, i);
}
return 0;
}
static void
emmciosetup(SDio*, int write, void *buf, int bsize, int bcount)
{
USED(write);
USED(buf);
WR(Blksizecnt, bcount<<16 | bsize);
}
static void
emmcio(SDio*, int write, uchar *buf, int len)
{
u32int *r = (u32int*)EMMCREGS;
int i;
assert((len&3) == 0);
okay(1);
if(waserror()){
okay(0);
nexterror();
}
if(write)
dmastart(DmaChanEmmc, DmaDevEmmc, DmaM2D,
buf, &r[Data], len);
else
dmastart(DmaChanEmmc, DmaDevEmmc, DmaD2M,
&r[Data], buf, len);
if(dmawait(DmaChanEmmc) < 0)
error(Eio);
WR(Irpten, r[Irpten]|Datadone|Err);
tsleep(&emmc.r, datadone, 0, 3000);
i = r[Interrupt]&~Cardintr;
if((i & Datadone) == 0){
print("emmcio: %d timeout intr %ux stat %ux\n",
write, i, r[Status]);
WR(Interrupt, i);
error(Eio);
}
if(i & Err){
print("emmcio: %d error intr %ux stat %ux\n",
write, r[Interrupt], r[Status]);
WR(Interrupt, i);
error(Eio);
}
if(i)
WR(Interrupt, i);
poperror();
okay(0);
}
static void
emmcinterrupt(Ureg*, void*)
{
u32int *r = (u32int*)EMMCREGS;
int i;
i = r[Interrupt];
if(i&(Datadone|Err))
wakeup(&emmc.r);
WR(Irpten, r[Irpten] & ~i);
}
void
emmclink(void)
{
static SDio io = {
"emmc",
emmcinit,
emmcenable,
emmcinquiry,
emmccmd,
emmciosetup,
emmcio,
emmcbus,
};
addmmcio(&io);
}