diff options
Diffstat (limited to 'src/hw/i2c/exynos4210_i2c.c')
| -rw-r--r-- | src/hw/i2c/exynos4210_i2c.c | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/src/hw/i2c/exynos4210_i2c.c b/src/hw/i2c/exynos4210_i2c.c new file mode 100644 index 0000000..fb99dfd --- /dev/null +++ b/src/hw/i2c/exynos4210_i2c.c @@ -0,0 +1,336 @@ +/* + * Exynos4210 I2C Bus Serial Interface Emulation + * + * Copyright (C) 2012 Samsung Electronics Co Ltd. + * Maksim Kozlov, <m.kozlov@samsung.com> + * Igor Mitsyanko, <i.mitsyanko@samsung.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + * + */ + +#include "qemu/timer.h" +#include "hw/sysbus.h" +#include "hw/i2c/i2c.h" + +#ifndef EXYNOS4_I2C_DEBUG +#define EXYNOS4_I2C_DEBUG 0 +#endif + +#define TYPE_EXYNOS4_I2C "exynos4210.i2c" +#define EXYNOS4_I2C(obj) \ + OBJECT_CHECK(Exynos4210I2CState, (obj), TYPE_EXYNOS4_I2C) + +/* Exynos4210 I2C memory map */ +#define EXYNOS4_I2C_MEM_SIZE 0x14 +#define I2CCON_ADDR 0x00 /* control register */ +#define I2CSTAT_ADDR 0x04 /* control/status register */ +#define I2CADD_ADDR 0x08 /* address register */ +#define I2CDS_ADDR 0x0c /* data shift register */ +#define I2CLC_ADDR 0x10 /* line control register */ + +#define I2CCON_ACK_GEN (1 << 7) +#define I2CCON_INTRS_EN (1 << 5) +#define I2CCON_INT_PEND (1 << 4) + +#define EXYNOS4_I2C_MODE(reg) (((reg) >> 6) & 3) +#define I2C_IN_MASTER_MODE(reg) (((reg) >> 6) & 2) +#define I2CMODE_MASTER_Rx 0x2 +#define I2CMODE_MASTER_Tx 0x3 +#define I2CSTAT_LAST_BIT (1 << 0) +#define I2CSTAT_OUTPUT_EN (1 << 4) +#define I2CSTAT_START_BUSY (1 << 5) + + +#if EXYNOS4_I2C_DEBUG +#define DPRINT(fmt, args...) \ + do { fprintf(stderr, "QEMU I2C: "fmt, ## args); } while (0) + +static const char *exynos4_i2c_get_regname(unsigned offset) +{ + switch (offset) { + case I2CCON_ADDR: + return "I2CCON"; + case I2CSTAT_ADDR: + return "I2CSTAT"; + case I2CADD_ADDR: + return "I2CADD"; + case I2CDS_ADDR: + return "I2CDS"; + case I2CLC_ADDR: + return "I2CLC"; + default: + return "[?]"; + } +} + +#else +#define DPRINT(fmt, args...) do { } while (0) +#endif + +typedef struct Exynos4210I2CState { + SysBusDevice parent_obj; + + MemoryRegion iomem; + I2CBus *bus; + qemu_irq irq; + + uint8_t i2ccon; + uint8_t i2cstat; + uint8_t i2cadd; + uint8_t i2cds; + uint8_t i2clc; + bool scl_free; +} Exynos4210I2CState; + +static inline void exynos4210_i2c_raise_interrupt(Exynos4210I2CState *s) +{ + if (s->i2ccon & I2CCON_INTRS_EN) { + s->i2ccon |= I2CCON_INT_PEND; + qemu_irq_raise(s->irq); + } +} + +static void exynos4210_i2c_data_receive(void *opaque) +{ + Exynos4210I2CState *s = (Exynos4210I2CState *)opaque; + int ret; + + s->i2cstat &= ~I2CSTAT_LAST_BIT; + s->scl_free = false; + ret = i2c_recv(s->bus); + if (ret < 0 && (s->i2ccon & I2CCON_ACK_GEN)) { + s->i2cstat |= I2CSTAT_LAST_BIT; /* Data is not acknowledged */ + } else { + s->i2cds = ret; + } + exynos4210_i2c_raise_interrupt(s); +} + +static void exynos4210_i2c_data_send(void *opaque) +{ + Exynos4210I2CState *s = (Exynos4210I2CState *)opaque; + + s->i2cstat &= ~I2CSTAT_LAST_BIT; + s->scl_free = false; + if (i2c_send(s->bus, s->i2cds) < 0 && (s->i2ccon & I2CCON_ACK_GEN)) { + s->i2cstat |= I2CSTAT_LAST_BIT; + } + exynos4210_i2c_raise_interrupt(s); +} + +static uint64_t exynos4210_i2c_read(void *opaque, hwaddr offset, + unsigned size) +{ + Exynos4210I2CState *s = (Exynos4210I2CState *)opaque; + uint8_t value; + + switch (offset) { + case I2CCON_ADDR: + value = s->i2ccon; + break; + case I2CSTAT_ADDR: + value = s->i2cstat; + break; + case I2CADD_ADDR: + value = s->i2cadd; + break; + case I2CDS_ADDR: + value = s->i2cds; + s->scl_free = true; + if (EXYNOS4_I2C_MODE(s->i2cstat) == I2CMODE_MASTER_Rx && + (s->i2cstat & I2CSTAT_START_BUSY) && + !(s->i2ccon & I2CCON_INT_PEND)) { + exynos4210_i2c_data_receive(s); + } + break; + case I2CLC_ADDR: + value = s->i2clc; + break; + default: + value = 0; + DPRINT("ERROR: Bad read offset 0x%x\n", (unsigned int)offset); + break; + } + + DPRINT("read %s [0x%02x] -> 0x%02x\n", exynos4_i2c_get_regname(offset), + (unsigned int)offset, value); + return value; +} + +static void exynos4210_i2c_write(void *opaque, hwaddr offset, + uint64_t value, unsigned size) +{ + Exynos4210I2CState *s = (Exynos4210I2CState *)opaque; + uint8_t v = value & 0xff; + + DPRINT("write %s [0x%02x] <- 0x%02x\n", exynos4_i2c_get_regname(offset), + (unsigned int)offset, v); + + switch (offset) { + case I2CCON_ADDR: + s->i2ccon = (v & ~I2CCON_INT_PEND) | (s->i2ccon & I2CCON_INT_PEND); + if ((s->i2ccon & I2CCON_INT_PEND) && !(v & I2CCON_INT_PEND)) { + s->i2ccon &= ~I2CCON_INT_PEND; + qemu_irq_lower(s->irq); + if (!(s->i2ccon & I2CCON_INTRS_EN)) { + s->i2cstat &= ~I2CSTAT_START_BUSY; + } + + if (s->i2cstat & I2CSTAT_START_BUSY) { + if (s->scl_free) { + if (EXYNOS4_I2C_MODE(s->i2cstat) == I2CMODE_MASTER_Tx) { + exynos4210_i2c_data_send(s); + } else if (EXYNOS4_I2C_MODE(s->i2cstat) == + I2CMODE_MASTER_Rx) { + exynos4210_i2c_data_receive(s); + } + } else { + s->i2ccon |= I2CCON_INT_PEND; + qemu_irq_raise(s->irq); + } + } + } + break; + case I2CSTAT_ADDR: + s->i2cstat = + (s->i2cstat & I2CSTAT_START_BUSY) | (v & ~I2CSTAT_START_BUSY); + + if (!(s->i2cstat & I2CSTAT_OUTPUT_EN)) { + s->i2cstat &= ~I2CSTAT_START_BUSY; + s->scl_free = true; + qemu_irq_lower(s->irq); + break; + } + + /* Nothing to do if in i2c slave mode */ + if (!I2C_IN_MASTER_MODE(s->i2cstat)) { + break; + } + + if (v & I2CSTAT_START_BUSY) { + s->i2cstat &= ~I2CSTAT_LAST_BIT; + s->i2cstat |= I2CSTAT_START_BUSY; /* Line is busy */ + s->scl_free = false; + + /* Generate start bit and send slave address */ + if (i2c_start_transfer(s->bus, s->i2cds >> 1, s->i2cds & 0x1) && + (s->i2ccon & I2CCON_ACK_GEN)) { + s->i2cstat |= I2CSTAT_LAST_BIT; + } else if (EXYNOS4_I2C_MODE(s->i2cstat) == I2CMODE_MASTER_Rx) { + exynos4210_i2c_data_receive(s); + } + exynos4210_i2c_raise_interrupt(s); + } else { + i2c_end_transfer(s->bus); + if (!(s->i2ccon & I2CCON_INT_PEND)) { + s->i2cstat &= ~I2CSTAT_START_BUSY; + } + s->scl_free = true; + } + break; + case I2CADD_ADDR: + if ((s->i2cstat & I2CSTAT_OUTPUT_EN) == 0) { + s->i2cadd = v; + } + break; + case I2CDS_ADDR: + if (s->i2cstat & I2CSTAT_OUTPUT_EN) { + s->i2cds = v; + s->scl_free = true; + if (EXYNOS4_I2C_MODE(s->i2cstat) == I2CMODE_MASTER_Tx && + (s->i2cstat & I2CSTAT_START_BUSY) && + !(s->i2ccon & I2CCON_INT_PEND)) { + exynos4210_i2c_data_send(s); + } + } + break; + case I2CLC_ADDR: + s->i2clc = v; + break; + default: + DPRINT("ERROR: Bad write offset 0x%x\n", (unsigned int)offset); + break; + } +} + +static const MemoryRegionOps exynos4210_i2c_ops = { + .read = exynos4210_i2c_read, + .write = exynos4210_i2c_write, + .endianness = DEVICE_NATIVE_ENDIAN, +}; + +static const VMStateDescription exynos4210_i2c_vmstate = { + .name = "exynos4210.i2c", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT8(i2ccon, Exynos4210I2CState), + VMSTATE_UINT8(i2cstat, Exynos4210I2CState), + VMSTATE_UINT8(i2cds, Exynos4210I2CState), + VMSTATE_UINT8(i2cadd, Exynos4210I2CState), + VMSTATE_UINT8(i2clc, Exynos4210I2CState), + VMSTATE_BOOL(scl_free, Exynos4210I2CState), + VMSTATE_END_OF_LIST() + } +}; + +static void exynos4210_i2c_reset(DeviceState *d) +{ + Exynos4210I2CState *s = EXYNOS4_I2C(d); + + s->i2ccon = 0x00; + s->i2cstat = 0x00; + s->i2cds = 0xFF; + s->i2clc = 0x00; + s->i2cadd = 0xFF; + s->scl_free = true; +} + +static int exynos4210_i2c_realize(SysBusDevice *sbd) +{ + DeviceState *dev = DEVICE(sbd); + Exynos4210I2CState *s = EXYNOS4_I2C(dev); + + memory_region_init_io(&s->iomem, OBJECT(s), &exynos4210_i2c_ops, s, + TYPE_EXYNOS4_I2C, EXYNOS4_I2C_MEM_SIZE); + sysbus_init_mmio(sbd, &s->iomem); + sysbus_init_irq(sbd, &s->irq); + s->bus = i2c_init_bus(dev, "i2c"); + return 0; +} + +static void exynos4210_i2c_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass); + + dc->vmsd = &exynos4210_i2c_vmstate; + dc->reset = exynos4210_i2c_reset; + sbdc->init = exynos4210_i2c_realize; +} + +static const TypeInfo exynos4210_i2c_type_info = { + .name = TYPE_EXYNOS4_I2C, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(Exynos4210I2CState), + .class_init = exynos4210_i2c_class_init, +}; + +static void exynos4210_i2c_register_types(void) +{ + type_register_static(&exynos4210_i2c_type_info); +} + +type_init(exynos4210_i2c_register_types) |
