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 <bala...@eik.bme.hu>
---
hw/i2c/ppc4xx_i2c.c | 222 +++++++++++++++++++++-----------------------
include/hw/i2c/ppc4xx_i2c.h | 3 +-
2 files changed, 110 insertions(+), 115 deletions(-)
diff --git a/hw/i2c/ppc4xx_i2c.c b/hw/i2c/ppc4xx_i2c.c
index c0a1930..73d6ba5 100644
--- a/hw/i2c/ppc4xx_i2c.c
+++ b/hw/i2c/ppc4xx_i2c.c
@@ -38,13 +38,26 @@
#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_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)
#define IIC_DIRECTCNTL_SDAC (1 << 3)
@@ -56,21 +69,13 @@ 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 = (1 << 6);
i2c->clkdiv = 0;
i2c->intrmsk = 0;
i2c->xfrcnt = 0;
@@ -78,69 +83,29 @@ static void ppc4xx_i2c_reset(DeviceState *s)
i2c->directcntl = 0xf;
}
-static inline bool ppc4xx_i2c_is_master(PPC4xxI2CState *i2c)
-{
- return true;
-}
-
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)) {
+ 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:
@@ -160,6 +125,7 @@ static uint64_t ppc4xx_i2c_readb(void *opaque, hwaddr addr,
unsigned int size)
break;
case 9:
ret = i2c->extsts;
+ ret |= !!i2c_bus_busy(i2c->bus) << 4;
break;
case 10:
ret = i2c->lsadr;
@@ -203,70 +169,98 @@ static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr,
uint64_t value,
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;
- }
+ 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:
i2c->lmadr = value;
- if (i2c_bus_busy(i2c->bus)) {
- i2c_end_transfer(i2c->bus);
- }
break;
case 5:
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);
+ i2c->cntl = value & 0xfe;
+ 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 = (1 << 6);
+ 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->sts & IIC_STS_ERR) &&
+ i2c_send_recv(i2c->bus, &i2c->mdata[i], !recv)) {
+ i2c->sts |= IIC_STS_ERR;
+ i2c->extsts |= IIC_EXTSTS_XFRA;
+ break;
}
- 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;
+ if (value & IIC_CNTL_RPST || !(value & IIC_CNTL_CHT)) {
+ i2c_end_transfer(i2c->bus);
}
- } else {
- /* we actually already did the write transfer... */
- i2c->sts &= ~IIC_STS_PT;
+ }
+ 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;
+ 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);
+ i2c->sts &= ~(value & 0x0a);
+ if (value & IIC_STS_IRQA && i2c->mdcntl & IIC_MDCNTL_EINT) {
+ qemu_irq_lower(i2c->irq);
+ }
break;
case 9:
i2c->extsts &= ~(value & 0x8f);
@@ -287,12 +281,12 @@ static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr,
uint64_t value,
i2c->xfrcnt = value & 0x77;
break;
case 15:
+ 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:
i2c->directcntl = value & (IIC_DIRECTCNTL_SDAC & IIC_DIRECTCNTL_SCLC);
diff --git a/include/hw/i2c/ppc4xx_i2c.h b/include/hw/i2c/ppc4xx_i2c.h
index ea6c8e1..0891a9c 100644
--- a/include/hw/i2c/ppc4xx_i2c.h
+++ b/include/hw/i2c/ppc4xx_i2c.h
@@ -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;
--
2.7.6
