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qemu/hw/i2c/ppc4xx_i2c.c
Philippe Mathieu-Daudé f8ffea755c hw/i2c/ppc4xx_i2c: Replace i2c_send_recv() by i2c_recv() & i2c_send() 
Instead of using the confuse i2c_send_recv(), rewrite to directly
call i2c_recv() & i2c_send(), resulting in code easier to review.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
2021-07-08 14:15:01 -05:00

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/*
* PPC4xx I2C controller emulation
*
* Documentation: PPC405GP User's Manual, Chapter 22. IIC Bus Interface
*
* Copyright (c) 2007 Jocelyn Mayer
* Copyright (c) 2012 François Revol
* Copyright (c) 2016-2018 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
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "hw/i2c/ppc4xx_i2c.h"
#include "hw/irq.h"
#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)
#define IIC_DIRECTCNTL_SDAC (1 << 3)
#define IIC_DIRECTCNTL_SCLC (1 << 2)
#define IIC_DIRECTCNTL_MSDA (1 << 1)
#define IIC_DIRECTCNTL_MSCL (1 << 0)
static void ppc4xx_i2c_reset(DeviceState *s)
{
PPC4xxI2CState *i2c = PPC4xx_I2C(s);
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 = IIC_EXTSTS_BCS_FREE;
i2c->clkdiv = 0;
i2c->intrmsk = 0;
i2c->xfrcnt = 0;
i2c->xtcntlss = 0;
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 IIC_MDBUF:
if (i2c->mdidx < 0) {
ret = 0xff;
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 IIC_LMADR:
ret = i2c->lmadr;
break;
case IIC_HMADR:
ret = i2c->hmadr;
break;
case IIC_CNTL:
ret = i2c->cntl;
break;
case IIC_MDCNTL:
ret = i2c->mdcntl;
break;
case IIC_STS:
ret = i2c->sts;
break;
case IIC_EXTSTS:
ret = i2c_bus_busy(i2c->bus) ?
IIC_EXTSTS_BCS_BUSY : IIC_EXTSTS_BCS_FREE;
break;
case IIC_LSADR:
ret = i2c->lsadr;
break;
case IIC_HSADR:
ret = i2c->hsadr;
break;
case IIC_CLKDIV:
ret = i2c->clkdiv;
break;
case IIC_INTRMSK:
ret = i2c->intrmsk;
break;
case IIC_XFRCNT:
ret = i2c->xfrcnt;
break;
case IIC_XTCNTLSS:
ret = i2c->xtcntlss;
break;
case IIC_DIRECTCNTL:
ret = i2c->directcntl;
break;
default:
if (addr < PPC4xx_I2C_MEM_SIZE) {
qemu_log_mask(LOG_UNIMP, "%s: Unimplemented register 0x%"
HWADDR_PRIx "\n", __func__, addr);
} else {
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad address 0x%"
HWADDR_PRIx "\n", __func__, addr);
}
ret = 0;
break;
}
return ret;
}
static void ppc4xx_i2c_writeb(void *opaque, hwaddr addr, uint64_t value,
unsigned int size)
{
PPC4xxI2CState *i2c = opaque;
switch (addr) {
case IIC_MDBUF:
if (i2c->mdidx >= 3) {
break;
}
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 IIC_LMADR:
i2c->lmadr = value;
break;
case IIC_HMADR:
i2c->hmadr = value;
break;
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->sts & IIC_STS_ERR)) {
if (recv) {
i2c->mdata[i] = i2c_recv(i2c->bus);
} else if (i2c_send(i2c->bus, i2c->mdata[i]) < 0) {
i2c->sts |= IIC_STS_ERR;
i2c->extsts |= IIC_EXTSTS_XFRA;
break;
}
}
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 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 IIC_STS:
i2c->sts &= ~(value & 0x0a);
if (value & IIC_STS_IRQA && i2c->mdcntl & IIC_MDCNTL_EINT) {
qemu_irq_lower(i2c->irq);
}
break;
case IIC_EXTSTS:
i2c->extsts &= ~(value & 0x8f);
break;
case IIC_LSADR:
i2c->lsadr = value;
break;
case IIC_HSADR:
i2c->hsadr = value;
break;
case IIC_CLKDIV:
i2c->clkdiv = value;
break;
case IIC_INTRMSK:
i2c->intrmsk = value;
break;
case IIC_XFRCNT:
i2c->xfrcnt = value & 0x77;
break;
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;
}
break;
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,
i2c->directcntl & IIC_DIRECTCNTL_MSCL);
i2c->directcntl |= bitbang_i2c_set(&i2c->bitbang, BITBANG_I2C_SDA,
(value & IIC_DIRECTCNTL_SDAC) != 0) << 1;
break;
default:
if (addr < PPC4xx_I2C_MEM_SIZE) {
qemu_log_mask(LOG_UNIMP, "%s: Unimplemented register 0x%"
HWADDR_PRIx "\n", __func__, addr);
} else {
qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad address 0x%"
HWADDR_PRIx "\n", __func__, addr);
}
break;
}
}
static const MemoryRegionOps ppc4xx_i2c_ops = {
.read = ppc4xx_i2c_readb,
.write = ppc4xx_i2c_writeb,
.valid.min_access_size = 1,
.valid.max_access_size = 4,
.impl.min_access_size = 1,
.impl.max_access_size = 1,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static void ppc4xx_i2c_init(Object *o)
{
PPC4xxI2CState *s = PPC4xx_I2C(o);
memory_region_init_io(&s->iomem, OBJECT(s), &ppc4xx_i2c_ops, s,
TYPE_PPC4xx_I2C, PPC4xx_I2C_MEM_SIZE);
sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
sysbus_init_irq(SYS_BUS_DEVICE(s), &s->irq);
s->bus = i2c_init_bus(DEVICE(s), "i2c");
bitbang_i2c_init(&s->bitbang, s->bus);
}
static void ppc4xx_i2c_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->reset = ppc4xx_i2c_reset;
}
static const TypeInfo ppc4xx_i2c_type_info = {
.name = TYPE_PPC4xx_I2C,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(PPC4xxI2CState),
.instance_init = ppc4xx_i2c_init,
.class_init = ppc4xx_i2c_class_init,
};
static void ppc4xx_i2c_register_types(void)
{
type_register_static(&ppc4xx_i2c_type_info);
}
type_init(ppc4xx_i2c_register_types)
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