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ppc4xx_i2c: Rewrite to model hardware more closely 

Rewrite to make it closer to how real device works so that guest OS
drivers can access I2C devices. Previously this was only a hack to
allow U-Boot to get past accessing SPD EEPROMs but to support other
I2C devices and allow guests to access them we need to model real
device more properly.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
BALATON Zoltan 2018-06-29 00:38:33 +02:00 committed by David Gibson
parent 3c47beb8de
commit afb6e20429
2 changed files with 159 additions and 143 deletions
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299
hw/i2c/ppc4xx_i2c.c
View File

@ -34,16 +34,50 @@
#define PPC4xx_I2C_MEM_SIZE 18
enum {
IIC_MDBUF = 0,
/* IIC_SDBUF = 2, */
IIC_LMADR = 4,
IIC_HMADR,
IIC_CNTL,
IIC_MDCNTL,
IIC_STS,
IIC_EXTSTS,
IIC_LSADR,
IIC_HSADR,
IIC_CLKDIV,
IIC_INTRMSK,
IIC_XFRCNT,
IIC_XTCNTLSS,
IIC_DIRECTCNTL
/* IIC_INTR */
};
#define IIC_CNTL_PT (1 << 0)
#define IIC_CNTL_READ (1 << 1)
#define IIC_CNTL_CHT (1 << 2)
#define IIC_CNTL_RPST (1 << 3)
#define IIC_CNTL_AMD (1 << 6)
#define IIC_CNTL_HMT (1 << 7)
#define IIC_MDCNTL_EINT (1 << 2)
#define IIC_MDCNTL_ESM (1 << 3)
#define IIC_MDCNTL_FMDB (1 << 6)
#define IIC_STS_PT (1 << 0)
#define IIC_STS_IRQA (1 << 1)
#define IIC_STS_ERR (1 << 2)
#define IIC_STS_MDBF (1 << 4)
#define IIC_STS_MDBS (1 << 5)
#define IIC_EXTSTS_XFRA (1 << 0)
#define IIC_EXTSTS_BCS_FREE (4 << 4)
#define IIC_EXTSTS_BCS_BUSY (5 << 4)
#define IIC_INTRMSK_EIMTC (1 << 0)
#define IIC_INTRMSK_EITA (1 << 1)
#define IIC_INTRMSK_EIIC (1 << 2)
#define IIC_INTRMSK_EIHE (1 << 3)
#define IIC_XTCNTLSS_SRST (1 << 0)
@ -56,130 +90,83 @@ static void ppc4xx_i2c_reset(DeviceState *s)
{
PPC4xxI2CState *i2c = PPC4xx_I2C(s);
/* FIXME: Should also reset bus?
*if (s->address != ADDR_RESET) {
* i2c_end_transfer(s->bus);
*}
*/
i2c->mdata = 0;
i2c->lmadr = 0;
i2c->hmadr = 0;
i2c->mdidx = -1;
memset(i2c->mdata, 0, ARRAY_SIZE(i2c->mdata));
/* [hl][ms]addr are not affected by reset */
i2c->cntl = 0;
i2c->mdcntl = 0;
i2c->sts = 0;
i2c->extsts = 0x8f;
i2c->lsadr = 0;
i2c->hsadr = 0;
i2c->extsts = IIC_EXTSTS_BCS_FREE;
i2c->clkdiv = 0;
i2c->intrmsk = 0;
i2c->xfrcnt = 0;
i2c->xtcntlss = 0;
i2c->directcntl = 0xf;
}
static inline bool ppc4xx_i2c_is_master(PPC4xxI2CState *i2c)
{
return true;
i2c->directcntl = 0xf; /* all non-reserved bits set */
}
static uint64_t ppc4xx_i2c_readb(void *opaque, hwaddr addr, unsigned int size)
{
PPC4xxI2CState *i2c = PPC4xx_I2C(opaque);
uint64_t ret;
int i;
switch (addr) {
case 0:
ret = i2c->mdata;
if (ppc4xx_i2c_is_master(i2c)) {
case IIC_MDBUF:
if (i2c->mdidx < 0) {
ret = 0xff;
if (!(i2c->sts & IIC_STS_MDBS)) {
qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Trying to read "
"without starting transfer\n",
TYPE_PPC4xx_I2C, __func__);
} else {
int pending = (i2c->cntl >> 4) & 3;
/* get the next byte */
int byte = i2c_recv(i2c->bus);
if (byte < 0) {
qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: read failed "
"for device 0x%02x\n", TYPE_PPC4xx_I2C,
__func__, i2c->lmadr);
ret = 0xff;
} else {
ret = byte;
/* Raise interrupt if enabled */
/*ppc4xx_i2c_raise_interrupt(i2c)*/;
}
if (!pending) {
i2c->sts &= ~IIC_STS_MDBS;
/*i2c_end_transfer(i2c->bus);*/
/*} else if (i2c->cntl & (IIC_CNTL_RPST | IIC_CNTL_CHT)) {*/
} else if (pending) {
/* current smbus implementation doesn't like
multibyte xfer repeated start */
i2c_end_transfer(i2c->bus);
if (i2c_start_transfer(i2c->bus, i2c->lmadr >> 1, 1)) {
/* if non zero is returned, the adress is not valid */
i2c->sts &= ~IIC_STS_PT;
i2c->sts |= IIC_STS_ERR;
i2c->extsts |= IIC_EXTSTS_XFRA;
} else {
/*i2c->sts |= IIC_STS_PT;*/
i2c->sts |= IIC_STS_MDBS;
i2c->sts &= ~IIC_STS_ERR;
i2c->extsts = 0;
}
}
pending--;
i2c->cntl = (i2c->cntl & 0xcf) | (pending << 4);
}
} else {
qemu_log_mask(LOG_UNIMP, "[%s]%s: slave mode not implemented\n",
TYPE_PPC4xx_I2C, __func__);
break;
}
ret = i2c->mdata[0];
if (i2c->mdidx == 3) {
i2c->sts &= ~IIC_STS_MDBF;
} else if (i2c->mdidx == 0) {
i2c->sts &= ~IIC_STS_MDBS;
}
for (i = 0; i < i2c->mdidx; i++) {
i2c->mdata[i] = i2c->mdata[i + 1];
}
if (i2c->mdidx >= 0) {
i2c->mdidx--;
}
break;
case 4:
case IIC_LMADR:
ret = i2c->lmadr;
break;
case 5:
case IIC_HMADR:
ret = i2c->hmadr;
break;
case 6:
case IIC_CNTL:
ret = i2c->cntl;
break;
case 7:
case IIC_MDCNTL:
ret = i2c->mdcntl;
break;
case 8:
case IIC_STS:
ret = i2c->sts;
break;
case 9:
ret = i2c->extsts;
case IIC_EXTSTS:
ret = i2c_bus_busy(i2c->bus) ?
IIC_EXTSTS_BCS_BUSY : IIC_EXTSTS_BCS_FREE;
break;
case 10:
case IIC_LSADR:
ret = i2c->lsadr;
break;
case 11:
case IIC_HSADR:
ret = i2c->hsadr;
break;
case 12:
case IIC_CLKDIV:
ret = i2c->clkdiv;
break;
case 13:
case IIC_INTRMSK:
ret = i2c->intrmsk;
break;
case 14:
case IIC_XFRCNT:
ret = i2c->xfrcnt;
break;
case 15:
case IIC_XTCNTLSS:
ret = i2c->xtcntlss;
break;
case 16:
case IIC_DIRECTCNTL:
ret = i2c->directcntl;
break;
default:
@ -202,99 +189,127 @@ static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr, uint64_t value,
PPC4xxI2CState *i2c = opaque;
switch (addr) {
case 0:
i2c->mdata = value;
if (!i2c_bus_busy(i2c->bus)) {
/* assume we start a write transfer */
if (i2c_start_transfer(i2c->bus, i2c->lmadr >> 1, 0)) {
/* if non zero is returned, the adress is not valid */
i2c->sts &= ~IIC_STS_PT;
i2c->sts |= IIC_STS_ERR;
i2c->extsts |= IIC_EXTSTS_XFRA;
} else {
i2c->sts |= IIC_STS_PT;
i2c->sts &= ~IIC_STS_ERR;
i2c->extsts = 0;
}
case IIC_MDBUF:
if (i2c->mdidx >= 3) {
break;
}
if (i2c_bus_busy(i2c->bus)) {
if (i2c_send(i2c->bus, i2c->mdata)) {
/* if the target return non zero then end the transfer */
i2c->sts &= ~IIC_STS_PT;
i2c->sts |= IIC_STS_ERR;
i2c->extsts |= IIC_EXTSTS_XFRA;
i2c_end_transfer(i2c->bus);
}
i2c->mdata[++i2c->mdidx] = value;
if (i2c->mdidx == 3) {
i2c->sts |= IIC_STS_MDBF;
} else if (i2c->mdidx == 0) {
i2c->sts |= IIC_STS_MDBS;
}
break;
case 4:
case IIC_LMADR:
i2c->lmadr = value;
if (i2c_bus_busy(i2c->bus)) {
i2c_end_transfer(i2c->bus);
}
break;
case 5:
case IIC_HMADR:
i2c->hmadr = value;
break;
case 6:
i2c->cntl = value;
if (i2c->cntl & IIC_CNTL_PT) {
if (i2c->cntl & IIC_CNTL_READ) {
if (i2c_bus_busy(i2c->bus)) {
/* end previous transfer */
i2c->sts &= ~IIC_STS_PT;
i2c_end_transfer(i2c->bus);
case IIC_CNTL:
i2c->cntl = value & ~IIC_CNTL_PT;
if (value & IIC_CNTL_AMD) {
qemu_log_mask(LOG_UNIMP, "%s: only 7 bit addresses supported\n",
__func__);
}
if (value & IIC_CNTL_HMT && i2c_bus_busy(i2c->bus)) {
i2c_end_transfer(i2c->bus);
if (i2c->mdcntl & IIC_MDCNTL_EINT &&
i2c->intrmsk & IIC_INTRMSK_EIHE) {
i2c->sts |= IIC_STS_IRQA;
qemu_irq_raise(i2c->irq);
}
} else if (value & IIC_CNTL_PT) {
int recv = (value & IIC_CNTL_READ) >> 1;
int tct = value >> 4 & 3;
int i;
if (recv && (i2c->lmadr >> 1) >= 0x50 && (i2c->lmadr >> 1) < 0x58) {
/* smbus emulation does not like multi byte reads w/o restart */
value |= IIC_CNTL_RPST;
}
for (i = 0; i <= tct; i++) {
if (!i2c_bus_busy(i2c->bus)) {
i2c->extsts = IIC_EXTSTS_BCS_FREE;
if (i2c_start_transfer(i2c->bus, i2c->lmadr >> 1, recv)) {
i2c->sts |= IIC_STS_ERR;
i2c->extsts |= IIC_EXTSTS_XFRA;
break;
} else {
i2c->sts &= ~IIC_STS_ERR;
}
}
if (i2c_start_transfer(i2c->bus, i2c->lmadr >> 1, 1)) {
/* if non zero is returned, the adress is not valid */
i2c->sts &= ~IIC_STS_PT;
if (!(i2c->sts & IIC_STS_ERR) &&
i2c_send_recv(i2c->bus, &i2c->mdata[i], !recv)) {
i2c->sts |= IIC_STS_ERR;
i2c->extsts |= IIC_EXTSTS_XFRA;
} else {
/*i2c->sts |= IIC_STS_PT;*/
i2c->sts |= IIC_STS_MDBS;
i2c->sts &= ~IIC_STS_ERR;
i2c->extsts = 0;
break;
}
} else {
/* we actually already did the write transfer... */
i2c->sts &= ~IIC_STS_PT;
if (value & IIC_CNTL_RPST || !(value & IIC_CNTL_CHT)) {
i2c_end_transfer(i2c->bus);
}
}
i2c->xfrcnt = i;
i2c->mdidx = i - 1;
if (recv && i2c->mdidx >= 0) {
i2c->sts |= IIC_STS_MDBS;
}
if (recv && i2c->mdidx == 3) {
i2c->sts |= IIC_STS_MDBF;
}
if (i && i2c->mdcntl & IIC_MDCNTL_EINT &&
i2c->intrmsk & IIC_INTRMSK_EIMTC) {
i2c->sts |= IIC_STS_IRQA;
qemu_irq_raise(i2c->irq);
}
}
break;
case 7:
i2c->mdcntl = value & 0xdf;
case IIC_MDCNTL:
i2c->mdcntl = value & 0x3d;
if (value & IIC_MDCNTL_ESM) {
qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
__func__);
}
if (value & IIC_MDCNTL_FMDB) {
i2c->mdidx = -1;
memset(i2c->mdata, 0, ARRAY_SIZE(i2c->mdata));
i2c->sts &= ~(IIC_STS_MDBF | IIC_STS_MDBS);
}
break;
case 8:
i2c->sts &= ~(value & 0xa);
case IIC_STS:
i2c->sts &= ~(value & 0x0a);
if (value & IIC_STS_IRQA && i2c->mdcntl & IIC_MDCNTL_EINT) {
qemu_irq_lower(i2c->irq);
}
break;
case 9:
case IIC_EXTSTS:
i2c->extsts &= ~(value & 0x8f);
break;
case 10:
case IIC_LSADR:
i2c->lsadr = value;
break;
case 11:
case IIC_HSADR:
i2c->hsadr = value;
break;
case 12:
case IIC_CLKDIV:
i2c->clkdiv = value;
break;
case 13:
case IIC_INTRMSK:
i2c->intrmsk = value;
break;
case 14:
case IIC_XFRCNT:
i2c->xfrcnt = value & 0x77;
break;
case 15:
case IIC_XTCNTLSS:
i2c->xtcntlss &= ~(value & 0xf0);
if (value & IIC_XTCNTLSS_SRST) {
/* Is it actually a full reset? U-Boot sets some regs before */
ppc4xx_i2c_reset(DEVICE(i2c));
break;
}
i2c->xtcntlss = value;
break;
case 16:
case IIC_DIRECTCNTL:
i2c->directcntl = value & (IIC_DIRECTCNTL_SDAC & IIC_DIRECTCNTL_SCLC);
i2c->directcntl |= (value & IIC_DIRECTCNTL_SCLC ? 1 : 0);
bitbang_i2c_set(i2c->bitbang, BITBANG_I2C_SCL,

3
include/hw/i2c/ppc4xx_i2c.h
View File

@ -46,7 +46,8 @@ typedef struct PPC4xxI2CState {
qemu_irq irq;
MemoryRegion iomem;
bitbang_i2c_interface *bitbang;
uint8_t mdata;
int mdidx;
uint8_t mdata[4];
uint8_t lmadr;
uint8_t hmadr;
uint8_t cntl;