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ppc4xx_i2c: Implement basic I2C functions 

Enough to please U-Boot and make it able to detect SDRAM SPD EEPROMs

Signed-off-by: François Revol <revol@free.fr>
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
BALATON Zoltan 2017-12-16 23:42:14 +01:00 committed by David Gibson
parent 5690d9ecef
commit 7709dbf12c
2 changed files with 171 additions and 30 deletions
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198
hw/i2c/ppc4xx_i2c.c
View File

@ -2,6 +2,8 @@
* PPC4xx I2C controller emulation
*
* Copyright (c) 2007 Jocelyn Mayer
* Copyright (c) 2012 François Revol
* Copyright (c) 2016 BALATON Zoltan
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
@ -25,26 +27,118 @@
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "qemu/log.h"
#include "cpu.h"
#include "hw/hw.h"
#include "hw/i2c/ppc4xx_i2c.h"
/*#define DEBUG_I2C*/
#define PPC4xx_I2C_MEM_SIZE 0x12
#define PPC4xx_I2C_MEM_SIZE 0x11
#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_STS_PT (1 << 0)
#define IIC_STS_ERR (1 << 2)
#define IIC_STS_MDBS (1 << 5)
#define IIC_EXTSTS_XFRA (1 << 0)
#define IIC_XTCNTLSS_SRST (1 << 0)
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->cntl = 0;
i2c->mdcntl = 0;
i2c->sts = 0;
i2c->extsts = 0x8f;
i2c->sdata = 0;
i2c->lsadr = 0;
i2c->hsadr = 0;
i2c->clkdiv = 0;
i2c->intrmsk = 0;
i2c->xfrcnt = 0;
i2c->xtcntlss = 0;
i2c->directcntl = 0x0f;
i2c->intr = 0;
}
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;
#ifdef DEBUG_I2C
printf("%s: addr " TARGET_FMT_plx "\n", __func__, addr);
#endif
switch (addr) {
case 0x00:
/*i2c_readbyte(&i2c->mdata);*/
ret = i2c->mdata;
if (ppc4xx_i2c_is_master(i2c)) {
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;
case 0x02:
ret = i2c->sdata;
@ -88,13 +182,15 @@ static uint64_t ppc4xx_i2c_readb(void *opaque, hwaddr addr, unsigned int size)
case 0x10:
ret = i2c->directcntl;
break;
case 0x11:
ret = i2c->intr;
break;
default:
ret = 0x00;
qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad address at offset 0x%"
HWADDR_PRIx "\n", TYPE_PPC4xx_I2C, __func__, addr);
ret = 0;
break;
}
#ifdef DEBUG_I2C
printf("%s: addr " TARGET_FMT_plx " %02" PRIx64 "\n", __func__, addr, ret);
#endif
return ret;
}
@ -103,26 +199,70 @@ static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr, uint64_t value,
unsigned int size)
{
PPC4xxI2CState *i2c = opaque;
#ifdef DEBUG_I2C
printf("%s: addr " TARGET_FMT_plx " val %08" PRIx64 "\n",
__func__, addr, value);
#endif
switch (addr) {
case 0x00:
i2c->mdata = value;
/*i2c_sendbyte(&i2c->mdata);*/
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_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);
}
}
break;
case 0x02:
i2c->sdata = value;
break;
case 0x04:
i2c->lmadr = value;
if (i2c_bus_busy(i2c->bus)) {
i2c_end_transfer(i2c->bus);
}
break;
case 0x05:
i2c->hmadr = value;
break;
case 0x06:
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);
}
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;
}
} else {
/* we actually already did the write transfer... */
i2c->sts &= ~IIC_STS_PT;
}
}
break;
case 0x07:
i2c->mdcntl = value & 0xDF;
@ -135,6 +275,7 @@ static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr, uint64_t value,
break;
case 0x0A:
i2c->lsadr = value;
/*i2c_set_slave_address(i2c->bus, i2c->lsadr);*/
break;
case 0x0B:
i2c->hsadr = value;
@ -149,11 +290,23 @@ static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr, uint64_t value,
i2c->xfrcnt = value & 0x77;
break;
case 0x0F:
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 0x10:
i2c->directcntl = value & 0x7;
break;
case 0x11:
i2c->intr = value;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad address at offset 0x%"
HWADDR_PRIx "\n", TYPE_PPC4xx_I2C, __func__, addr);
break;
}
}
@ -167,21 +320,6 @@ static const MemoryRegionOps ppc4xx_i2c_ops = {
.endianness = DEVICE_NATIVE_ENDIAN,
};
static void ppc4xx_i2c_reset(DeviceState *s)
{
PPC4xxI2CState *i2c = PPC4xx_I2C(s);
i2c->mdata = 0x00;
i2c->sdata = 0x00;
i2c->cntl = 0x00;
i2c->mdcntl = 0x00;
i2c->sts = 0x00;
i2c->extsts = 0x00;
i2c->clkdiv = 0x00;
i2c->xfrcnt = 0x00;
i2c->directcntl = 0x0F;
}
static void ppc4xx_i2c_init(Object *o)
{
PPC4xxI2CState *s = PPC4xx_I2C(o);

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

@ -2,6 +2,8 @@
* PPC4xx I2C controller emulation
*
* Copyright (c) 2007 Jocelyn Mayer
* Copyright (c) 2012 François Revol
* Copyright (c) 2016 BALATON Zoltan
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
@ -55,6 +57,7 @@ typedef struct PPC4xxI2CState {
uint8_t xfrcnt;
uint8_t xtcntlss;
uint8_t directcntl;
uint8_t intr;
} PPC4xxI2CState;
#endif /* PPC4XX_I2C_H */