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qemu/hw/i2c/mpc_i2c.c

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/*
* Copyright (C) 2014 Freescale Semiconductor, Inc. All rights reserved.
*
* Author: Amit Tomar, <Amit.Tomar@freescale.com>
*
* Description:
* This file is derived from IMX I2C controller,
* by Jean-Christophe DUBOIS .
*
* Thanks to Scott Wood and Alexander Graf for their kind help on this.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2 or later,
* as published by the Free Software Foundation.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "hw/i2c/i2c.h"
#include "hw/irq.h"
#include "qemu/module.h"
#include "hw/sysbus.h"
#include "migration/vmstate.h"
#include "qom/object.h"
/* #define DEBUG_I2C */
#ifdef DEBUG_I2C
#define DPRINTF(fmt, ...) \
do { fprintf(stderr, "mpc_i2c[%s]: " fmt, __func__, ## __VA_ARGS__); \
} while (0)
#else
#define DPRINTF(fmt, ...) do {} while (0)
#endif
#define TYPE_MPC_I2C "mpc-i2c"
OBJECT_DECLARE_SIMPLE_TYPE(MPCI2CState, MPC_I2C)
#define MPC_I2C_ADR 0x00
#define MPC_I2C_FDR 0x04
#define MPC_I2C_CR 0x08
#define MPC_I2C_SR 0x0c
#define MPC_I2C_DR 0x10
#define MPC_I2C_DFSRR 0x14
#define CCR_MEN (1 << 7)
#define CCR_MIEN (1 << 6)
#define CCR_MSTA (1 << 5)
#define CCR_MTX (1 << 4)
#define CCR_TXAK (1 << 3)
#define CCR_RSTA (1 << 2)
#define CCR_BCST (1 << 0)
#define CSR_MCF (1 << 7)
#define CSR_MAAS (1 << 6)
#define CSR_MBB (1 << 5)
#define CSR_MAL (1 << 4)
#define CSR_SRW (1 << 2)
#define CSR_MIF (1 << 1)
#define CSR_RXAK (1 << 0)
#define CADR_MASK 0xFE
#define CFDR_MASK 0x3F
#define CCR_MASK 0xFC
#define CSR_MASK 0xED
#define CDR_MASK 0xFF
#define CYCLE_RESET 0xFF
struct MPCI2CState {
SysBusDevice parent_obj;
I2CBus *bus;
qemu_irq irq;
MemoryRegion iomem;
uint8_t address;
uint8_t adr;
uint8_t fdr;
uint8_t cr;
uint8_t sr;
uint8_t dr;
uint8_t dfssr;
};
static bool mpc_i2c_is_enabled(MPCI2CState *s)
{
return s->cr & CCR_MEN;
}
static bool mpc_i2c_is_master(MPCI2CState *s)
{
return s->cr & CCR_MSTA;
}
static bool mpc_i2c_direction_is_tx(MPCI2CState *s)
{
return s->cr & CCR_MTX;
}
static bool mpc_i2c_irq_pending(MPCI2CState *s)
{
return s->sr & CSR_MIF;
}
static bool mpc_i2c_irq_is_enabled(MPCI2CState *s)
{
return s->cr & CCR_MIEN;
}
static void mpc_i2c_reset(DeviceState *dev)
{
MPCI2CState *i2c = MPC_I2C(dev);
i2c->address = 0xFF;
i2c->adr = 0x00;
i2c->fdr = 0x00;
i2c->cr = 0x00;
i2c->sr = 0x81;
i2c->dr = 0x00;
}
static void mpc_i2c_irq(MPCI2CState *s)
{
bool irq_active = false;
if (mpc_i2c_is_enabled(s) && mpc_i2c_irq_is_enabled(s)
&& mpc_i2c_irq_pending(s)) {
irq_active = true;
}
if (irq_active) {
qemu_irq_raise(s->irq);
} else {
qemu_irq_lower(s->irq);
}
}
static void mpc_i2c_soft_reset(MPCI2CState *s)
{
/* This is a soft reset. ADR is preserved during soft resets */
uint8_t adr = s->adr;
mpc_i2c_reset(DEVICE(s));
s->adr = adr;
}
static void mpc_i2c_address_send(MPCI2CState *s)
{
/* if returns non zero slave address is not right */
if (i2c_start_transfer(s->bus, s->dr >> 1, s->dr & (0x01))) {
s->sr |= CSR_RXAK;
} else {
s->address = s->dr;
s->sr &= ~CSR_RXAK;
s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
mpc_i2c_irq(s);
}
}
static void mpc_i2c_data_send(MPCI2CState *s)
{
if (i2c_send(s->bus, s->dr)) {
/* End of transfer */
s->sr |= CSR_RXAK;
i2c_end_transfer(s->bus);
} else {
s->sr &= ~CSR_RXAK;
s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
mpc_i2c_irq(s);
}
}
static void mpc_i2c_data_recive(MPCI2CState *s)
{
int ret;
/* get the next byte */
ret = i2c_recv(s->bus);
if (ret >= 0) {
s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */
s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */
mpc_i2c_irq(s);
} else {
DPRINTF("read failed for device");
ret = 0xff;
}
s->dr = ret;
}
static uint64_t mpc_i2c_read(void *opaque, hwaddr addr, unsigned size)
{
MPCI2CState *s = opaque;
uint8_t value;
switch (addr) {
case MPC_I2C_ADR:
value = s->adr;
break;
case MPC_I2C_FDR:
value = s->fdr;
break;
case MPC_I2C_CR:
value = s->cr;
break;
case MPC_I2C_SR:
value = s->sr;
break;
case MPC_I2C_DR:
value = s->dr;
if (mpc_i2c_is_master(s)) { /* master mode */
if (mpc_i2c_direction_is_tx(s)) {
DPRINTF("MTX is set not in recv mode\n");
} else {
mpc_i2c_data_recive(s);
}
}
break;
default:
value = 0;
DPRINTF("ERROR: Bad read addr 0x%x\n", (unsigned int)addr);
break;
}
DPRINTF("%s: addr " TARGET_FMT_plx " %02" PRIx32 "\n", __func__,
addr, value);
return (uint64_t)value;
}
static void mpc_i2c_write(void *opaque, hwaddr addr,
uint64_t value, unsigned size)
{
MPCI2CState *s = opaque;
DPRINTF("%s: addr " TARGET_FMT_plx " val %08" PRIx64 "\n", __func__,
addr, value);
switch (addr) {
case MPC_I2C_ADR:
s->adr = value & CADR_MASK;
break;
case MPC_I2C_FDR:
s->fdr = value & CFDR_MASK;
break;
case MPC_I2C_CR:
if (mpc_i2c_is_enabled(s) && ((value & CCR_MEN) == 0)) {
mpc_i2c_soft_reset(s);
break;
}
/* normal write */
s->cr = value & CCR_MASK;
if (mpc_i2c_is_master(s)) { /* master mode */
/* set the bus to busy after master is set as per RM */
s->sr |= CSR_MBB;
} else {
/* bus is not busy anymore */
s->sr &= ~CSR_MBB;
/* Reset the address for fresh write/read cycle */
if (s->address != CYCLE_RESET) {
i2c_end_transfer(s->bus);
s->address = CYCLE_RESET;
}
}
/* For restart end the onging transfer */
if (s->cr & CCR_RSTA) {
if (s->address != CYCLE_RESET) {
s->address = CYCLE_RESET;
i2c_end_transfer(s->bus);
s->cr &= ~CCR_RSTA;
}
}
break;
case MPC_I2C_SR:
s->sr = value & CSR_MASK;
/* Lower the interrupt */
if (!(s->sr & CSR_MIF) || !(s->sr & CSR_MAL)) {
mpc_i2c_irq(s);
}
break;
case MPC_I2C_DR:
/* if the device is not enabled, nothing to do */
if (!mpc_i2c_is_enabled(s)) {
break;
}
s->dr = value & CDR_MASK;
if (mpc_i2c_is_master(s)) { /* master mode */
if (s->address == CYCLE_RESET) {
mpc_i2c_address_send(s);
} else {
mpc_i2c_data_send(s);
}
}
break;
case MPC_I2C_DFSRR:
s->dfssr = value;
break;
default:
DPRINTF("ERROR: Bad write addr 0x%x\n", (unsigned int)addr);
break;
}
}
static const MemoryRegionOps i2c_ops = {
.read = mpc_i2c_read,
.write = mpc_i2c_write,
.valid.max_access_size = 1,
.endianness = DEVICE_NATIVE_ENDIAN,
};
static const VMStateDescription mpc_i2c_vmstate = {
.name = TYPE_MPC_I2C,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT8(address, MPCI2CState),
VMSTATE_UINT8(adr, MPCI2CState),
VMSTATE_UINT8(fdr, MPCI2CState),
VMSTATE_UINT8(cr, MPCI2CState),
VMSTATE_UINT8(sr, MPCI2CState),
VMSTATE_UINT8(dr, MPCI2CState),
VMSTATE_UINT8(dfssr, MPCI2CState),
VMSTATE_END_OF_LIST()
}
};
static void mpc_i2c_realize(DeviceState *dev, Error **errp)
{
MPCI2CState *i2c = MPC_I2C(dev);
sysbus_init_irq(SYS_BUS_DEVICE(dev), &i2c->irq);
memory_region_init_io(&i2c->iomem, OBJECT(i2c), &i2c_ops, i2c,
"mpc-i2c", 0x14);
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &i2c->iomem);
i2c->bus = i2c_init_bus(dev, "i2c");
}
static void mpc_i2c_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->vmsd = &mpc_i2c_vmstate ;
dc->reset = mpc_i2c_reset;
dc->realize = mpc_i2c_realize;
dc->desc = "MPC I2C Controller";
}
static const TypeInfo mpc_i2c_type_info = {
.name = TYPE_MPC_I2C,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(MPCI2CState),
.class_init = mpc_i2c_class_init,
};
static void mpc_i2c_register_types(void)
{
type_register_static(&mpc_i2c_type_info);
}
type_init(mpc_i2c_register_types)
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