diff options
Diffstat (limited to 'hw/i2c/mpc_i2c.c')
-rw-r--r-- | hw/i2c/mpc_i2c.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/hw/i2c/mpc_i2c.c b/hw/i2c/mpc_i2c.c new file mode 100644 index 0000000000..693ca7ef6b --- /dev/null +++ b/hw/i2c/mpc_i2c.c @@ -0,0 +1,357 @@ +/* + * 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 "qemu/log.h" +#include "hw/sysbus.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" +#define MPC_I2C(obj) \ + OBJECT_CHECK(MPCI2CState, (obj), TYPE_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 + +typedef 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; +} MPCI2CState; + +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(DEVICE(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) |