diff options
Diffstat (limited to 'hw/char/exynos4210_uart.c')
| -rw-r--r-- | hw/char/exynos4210_uart.c | 676 |
1 files changed, 676 insertions, 0 deletions
diff --git a/hw/char/exynos4210_uart.c b/hw/char/exynos4210_uart.c new file mode 100644 index 0000000000..8b4e72ca11 --- /dev/null +++ b/hw/char/exynos4210_uart.c @@ -0,0 +1,676 @@ +/* + * Exynos4210 UART Emulation + * + * Copyright (C) 2011 Samsung Electronics Co Ltd. + * Maksim Kozlov, <m.kozlov@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 "hw/sysbus.h" +#include "sysemu/sysemu.h" +#include "char/char.h" + +#include "hw/arm/exynos4210.h" + +#undef DEBUG_UART +#undef DEBUG_UART_EXTEND +#undef DEBUG_IRQ +#undef DEBUG_Rx_DATA +#undef DEBUG_Tx_DATA + +#define DEBUG_UART 0 +#define DEBUG_UART_EXTEND 0 +#define DEBUG_IRQ 0 +#define DEBUG_Rx_DATA 0 +#define DEBUG_Tx_DATA 0 + +#if DEBUG_UART +#define PRINT_DEBUG(fmt, args...) \ + do { \ + fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \ + } while (0) + +#if DEBUG_UART_EXTEND +#define PRINT_DEBUG_EXTEND(fmt, args...) \ + do { \ + fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \ + } while (0) +#else +#define PRINT_DEBUG_EXTEND(fmt, args...) \ + do {} while (0) +#endif /* EXTEND */ + +#else +#define PRINT_DEBUG(fmt, args...) \ + do {} while (0) +#define PRINT_DEBUG_EXTEND(fmt, args...) \ + do {} while (0) +#endif + +#define PRINT_ERROR(fmt, args...) \ + do { \ + fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \ + } while (0) + +/* + * Offsets for UART registers relative to SFR base address + * for UARTn + * + */ +#define ULCON 0x0000 /* Line Control */ +#define UCON 0x0004 /* Control */ +#define UFCON 0x0008 /* FIFO Control */ +#define UMCON 0x000C /* Modem Control */ +#define UTRSTAT 0x0010 /* Tx/Rx Status */ +#define UERSTAT 0x0014 /* UART Error Status */ +#define UFSTAT 0x0018 /* FIFO Status */ +#define UMSTAT 0x001C /* Modem Status */ +#define UTXH 0x0020 /* Transmit Buffer */ +#define URXH 0x0024 /* Receive Buffer */ +#define UBRDIV 0x0028 /* Baud Rate Divisor */ +#define UFRACVAL 0x002C /* Divisor Fractional Value */ +#define UINTP 0x0030 /* Interrupt Pending */ +#define UINTSP 0x0034 /* Interrupt Source Pending */ +#define UINTM 0x0038 /* Interrupt Mask */ + +/* + * for indexing register in the uint32_t array + * + * 'reg' - register offset (see offsets definitions above) + * + */ +#define I_(reg) (reg / sizeof(uint32_t)) + +typedef struct Exynos4210UartReg { + const char *name; /* the only reason is the debug output */ + hwaddr offset; + uint32_t reset_value; +} Exynos4210UartReg; + +static Exynos4210UartReg exynos4210_uart_regs[] = { + {"ULCON", ULCON, 0x00000000}, + {"UCON", UCON, 0x00003000}, + {"UFCON", UFCON, 0x00000000}, + {"UMCON", UMCON, 0x00000000}, + {"UTRSTAT", UTRSTAT, 0x00000006}, /* RO */ + {"UERSTAT", UERSTAT, 0x00000000}, /* RO */ + {"UFSTAT", UFSTAT, 0x00000000}, /* RO */ + {"UMSTAT", UMSTAT, 0x00000000}, /* RO */ + {"UTXH", UTXH, 0x5c5c5c5c}, /* WO, undefined reset value*/ + {"URXH", URXH, 0x00000000}, /* RO */ + {"UBRDIV", UBRDIV, 0x00000000}, + {"UFRACVAL", UFRACVAL, 0x00000000}, + {"UINTP", UINTP, 0x00000000}, + {"UINTSP", UINTSP, 0x00000000}, + {"UINTM", UINTM, 0x00000000}, +}; + +#define EXYNOS4210_UART_REGS_MEM_SIZE 0x3C + +/* UART FIFO Control */ +#define UFCON_FIFO_ENABLE 0x1 +#define UFCON_Rx_FIFO_RESET 0x2 +#define UFCON_Tx_FIFO_RESET 0x4 +#define UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT 8 +#define UFCON_Tx_FIFO_TRIGGER_LEVEL (7 << UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT) +#define UFCON_Rx_FIFO_TRIGGER_LEVEL_SHIFT 4 +#define UFCON_Rx_FIFO_TRIGGER_LEVEL (7 << UFCON_Rx_FIFO_TRIGGER_LEVEL_SHIFT) + +/* Uart FIFO Status */ +#define UFSTAT_Rx_FIFO_COUNT 0xff +#define UFSTAT_Rx_FIFO_FULL 0x100 +#define UFSTAT_Rx_FIFO_ERROR 0x200 +#define UFSTAT_Tx_FIFO_COUNT_SHIFT 16 +#define UFSTAT_Tx_FIFO_COUNT (0xff << UFSTAT_Tx_FIFO_COUNT_SHIFT) +#define UFSTAT_Tx_FIFO_FULL_SHIFT 24 +#define UFSTAT_Tx_FIFO_FULL (1 << UFSTAT_Tx_FIFO_FULL_SHIFT) + +/* UART Interrupt Source Pending */ +#define UINTSP_RXD 0x1 /* Receive interrupt */ +#define UINTSP_ERROR 0x2 /* Error interrupt */ +#define UINTSP_TXD 0x4 /* Transmit interrupt */ +#define UINTSP_MODEM 0x8 /* Modem interrupt */ + +/* UART Line Control */ +#define ULCON_IR_MODE_SHIFT 6 +#define ULCON_PARITY_SHIFT 3 +#define ULCON_STOP_BIT_SHIFT 1 + +/* UART Tx/Rx Status */ +#define UTRSTAT_TRANSMITTER_EMPTY 0x4 +#define UTRSTAT_Tx_BUFFER_EMPTY 0x2 +#define UTRSTAT_Rx_BUFFER_DATA_READY 0x1 + +/* UART Error Status */ +#define UERSTAT_OVERRUN 0x1 +#define UERSTAT_PARITY 0x2 +#define UERSTAT_FRAME 0x4 +#define UERSTAT_BREAK 0x8 + +typedef struct { + uint8_t *data; + uint32_t sp, rp; /* store and retrieve pointers */ + uint32_t size; +} Exynos4210UartFIFO; + +typedef struct { + SysBusDevice busdev; + MemoryRegion iomem; + + uint32_t reg[EXYNOS4210_UART_REGS_MEM_SIZE / sizeof(uint32_t)]; + Exynos4210UartFIFO rx; + Exynos4210UartFIFO tx; + + CharDriverState *chr; + qemu_irq irq; + + uint32_t channel; + +} Exynos4210UartState; + + +#if DEBUG_UART +/* Used only for debugging inside PRINT_DEBUG_... macros */ +static const char *exynos4210_uart_regname(hwaddr offset) +{ + + int regs_number = sizeof(exynos4210_uart_regs) / sizeof(Exynos4210UartReg); + int i; + + for (i = 0; i < regs_number; i++) { + if (offset == exynos4210_uart_regs[i].offset) { + return exynos4210_uart_regs[i].name; + } + } + + return NULL; +} +#endif + + +static void fifo_store(Exynos4210UartFIFO *q, uint8_t ch) +{ + q->data[q->sp] = ch; + q->sp = (q->sp + 1) % q->size; +} + +static uint8_t fifo_retrieve(Exynos4210UartFIFO *q) +{ + uint8_t ret = q->data[q->rp]; + q->rp = (q->rp + 1) % q->size; + return ret; +} + +static int fifo_elements_number(Exynos4210UartFIFO *q) +{ + if (q->sp < q->rp) { + return q->size - q->rp + q->sp; + } + + return q->sp - q->rp; +} + +static int fifo_empty_elements_number(Exynos4210UartFIFO *q) +{ + return q->size - fifo_elements_number(q); +} + +static void fifo_reset(Exynos4210UartFIFO *q) +{ + if (q->data != NULL) { + g_free(q->data); + q->data = NULL; + } + + q->data = (uint8_t *)g_malloc0(q->size); + + q->sp = 0; + q->rp = 0; +} + +static uint32_t exynos4210_uart_Tx_FIFO_trigger_level(Exynos4210UartState *s) +{ + uint32_t level = 0; + uint32_t reg; + + reg = (s->reg[I_(UFCON)] & UFCON_Tx_FIFO_TRIGGER_LEVEL) >> + UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT; + + switch (s->channel) { + case 0: + level = reg * 32; + break; + case 1: + case 4: + level = reg * 8; + break; + case 2: + case 3: + level = reg * 2; + break; + default: + level = 0; + PRINT_ERROR("Wrong UART channel number: %d\n", s->channel); + } + + return level; +} + +static void exynos4210_uart_update_irq(Exynos4210UartState *s) +{ + /* + * The Tx interrupt is always requested if the number of data in the + * transmit FIFO is smaller than the trigger level. + */ + if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) { + + uint32_t count = (s->reg[I_(UFSTAT)] & UFSTAT_Tx_FIFO_COUNT) >> + UFSTAT_Tx_FIFO_COUNT_SHIFT; + + if (count <= exynos4210_uart_Tx_FIFO_trigger_level(s)) { + s->reg[I_(UINTSP)] |= UINTSP_TXD; + } + } + + s->reg[I_(UINTP)] = s->reg[I_(UINTSP)] & ~s->reg[I_(UINTM)]; + + if (s->reg[I_(UINTP)]) { + qemu_irq_raise(s->irq); + +#if DEBUG_IRQ + fprintf(stderr, "UART%d: IRQ has been raised: %08x\n", + s->channel, s->reg[I_(UINTP)]); +#endif + + } else { + qemu_irq_lower(s->irq); + } +} + +static void exynos4210_uart_update_parameters(Exynos4210UartState *s) +{ + int speed, parity, data_bits, stop_bits, frame_size; + QEMUSerialSetParams ssp; + uint64_t uclk_rate; + + if (s->reg[I_(UBRDIV)] == 0) { + return; + } + + frame_size = 1; /* start bit */ + if (s->reg[I_(ULCON)] & 0x20) { + frame_size++; /* parity bit */ + if (s->reg[I_(ULCON)] & 0x28) { + parity = 'E'; + } else { + parity = 'O'; + } + } else { + parity = 'N'; + } + + if (s->reg[I_(ULCON)] & 0x4) { + stop_bits = 2; + } else { + stop_bits = 1; + } + + data_bits = (s->reg[I_(ULCON)] & 0x3) + 5; + + frame_size += data_bits + stop_bits; + + uclk_rate = 24000000; + + speed = uclk_rate / ((16 * (s->reg[I_(UBRDIV)]) & 0xffff) + + (s->reg[I_(UFRACVAL)] & 0x7) + 16); + + ssp.speed = speed; + ssp.parity = parity; + ssp.data_bits = data_bits; + ssp.stop_bits = stop_bits; + + qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); + + PRINT_DEBUG("UART%d: speed: %d, parity: %c, data: %d, stop: %d\n", + s->channel, speed, parity, data_bits, stop_bits); +} + +static void exynos4210_uart_write(void *opaque, hwaddr offset, + uint64_t val, unsigned size) +{ + Exynos4210UartState *s = (Exynos4210UartState *)opaque; + uint8_t ch; + + PRINT_DEBUG_EXTEND("UART%d: <0x%04x> %s <- 0x%08llx\n", s->channel, + offset, exynos4210_uart_regname(offset), (long long unsigned int)val); + + switch (offset) { + case ULCON: + case UBRDIV: + case UFRACVAL: + s->reg[I_(offset)] = val; + exynos4210_uart_update_parameters(s); + break; + case UFCON: + s->reg[I_(UFCON)] = val; + if (val & UFCON_Rx_FIFO_RESET) { + fifo_reset(&s->rx); + s->reg[I_(UFCON)] &= ~UFCON_Rx_FIFO_RESET; + PRINT_DEBUG("UART%d: Rx FIFO Reset\n", s->channel); + } + if (val & UFCON_Tx_FIFO_RESET) { + fifo_reset(&s->tx); + s->reg[I_(UFCON)] &= ~UFCON_Tx_FIFO_RESET; + PRINT_DEBUG("UART%d: Tx FIFO Reset\n", s->channel); + } + break; + + case UTXH: + if (s->chr) { + s->reg[I_(UTRSTAT)] &= ~(UTRSTAT_TRANSMITTER_EMPTY | + UTRSTAT_Tx_BUFFER_EMPTY); + ch = (uint8_t)val; + qemu_chr_fe_write(s->chr, &ch, 1); +#if DEBUG_Tx_DATA + fprintf(stderr, "%c", ch); +#endif + s->reg[I_(UTRSTAT)] |= UTRSTAT_TRANSMITTER_EMPTY | + UTRSTAT_Tx_BUFFER_EMPTY; + s->reg[I_(UINTSP)] |= UINTSP_TXD; + exynos4210_uart_update_irq(s); + } + break; + + case UINTP: + s->reg[I_(UINTP)] &= ~val; + s->reg[I_(UINTSP)] &= ~val; + PRINT_DEBUG("UART%d: UINTP [%04x] have been cleared: %08x\n", + s->channel, offset, s->reg[I_(UINTP)]); + exynos4210_uart_update_irq(s); + break; + case UTRSTAT: + case UERSTAT: + case UFSTAT: + case UMSTAT: + case URXH: + PRINT_DEBUG("UART%d: Trying to write into RO register: %s [%04x]\n", + s->channel, exynos4210_uart_regname(offset), offset); + break; + case UINTSP: + s->reg[I_(UINTSP)] &= ~val; + break; + case UINTM: + s->reg[I_(UINTM)] = val; + exynos4210_uart_update_irq(s); + break; + case UCON: + case UMCON: + default: + s->reg[I_(offset)] = val; + break; + } +} +static uint64_t exynos4210_uart_read(void *opaque, hwaddr offset, + unsigned size) +{ + Exynos4210UartState *s = (Exynos4210UartState *)opaque; + uint32_t res; + + switch (offset) { + case UERSTAT: /* Read Only */ + res = s->reg[I_(UERSTAT)]; + s->reg[I_(UERSTAT)] = 0; + return res; + case UFSTAT: /* Read Only */ + s->reg[I_(UFSTAT)] = fifo_elements_number(&s->rx) & 0xff; + if (fifo_empty_elements_number(&s->rx) == 0) { + s->reg[I_(UFSTAT)] |= UFSTAT_Rx_FIFO_FULL; + s->reg[I_(UFSTAT)] &= ~0xff; + } + return s->reg[I_(UFSTAT)]; + case URXH: + if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) { + if (fifo_elements_number(&s->rx)) { + res = fifo_retrieve(&s->rx); +#if DEBUG_Rx_DATA + fprintf(stderr, "%c", res); +#endif + if (!fifo_elements_number(&s->rx)) { + s->reg[I_(UTRSTAT)] &= ~UTRSTAT_Rx_BUFFER_DATA_READY; + } else { + s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY; + } + } else { + s->reg[I_(UINTSP)] |= UINTSP_ERROR; + exynos4210_uart_update_irq(s); + res = 0; + } + } else { + s->reg[I_(UTRSTAT)] &= ~UTRSTAT_Rx_BUFFER_DATA_READY; + res = s->reg[I_(URXH)]; + } + return res; + case UTXH: + PRINT_DEBUG("UART%d: Trying to read from WO register: %s [%04x]\n", + s->channel, exynos4210_uart_regname(offset), offset); + break; + default: + return s->reg[I_(offset)]; + } + + return 0; +} + +static const MemoryRegionOps exynos4210_uart_ops = { + .read = exynos4210_uart_read, + .write = exynos4210_uart_write, + .endianness = DEVICE_NATIVE_ENDIAN, + .valid = { + .max_access_size = 4, + .unaligned = false + }, +}; + +static int exynos4210_uart_can_receive(void *opaque) +{ + Exynos4210UartState *s = (Exynos4210UartState *)opaque; + + return fifo_empty_elements_number(&s->rx); +} + + +static void exynos4210_uart_receive(void *opaque, const uint8_t *buf, int size) +{ + Exynos4210UartState *s = (Exynos4210UartState *)opaque; + int i; + + if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) { + if (fifo_empty_elements_number(&s->rx) < size) { + for (i = 0; i < fifo_empty_elements_number(&s->rx); i++) { + fifo_store(&s->rx, buf[i]); + } + s->reg[I_(UINTSP)] |= UINTSP_ERROR; + s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY; + } else { + for (i = 0; i < size; i++) { + fifo_store(&s->rx, buf[i]); + } + s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY; + } + /* XXX: Around here we maybe should check Rx trigger level */ + s->reg[I_(UINTSP)] |= UINTSP_RXD; + } else { + s->reg[I_(URXH)] = buf[0]; + s->reg[I_(UINTSP)] |= UINTSP_RXD; + s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY; + } + + exynos4210_uart_update_irq(s); +} + + +static void exynos4210_uart_event(void *opaque, int event) +{ + Exynos4210UartState *s = (Exynos4210UartState *)opaque; + + if (event == CHR_EVENT_BREAK) { + /* When the RxDn is held in logic 0, then a null byte is pushed into the + * fifo */ + fifo_store(&s->rx, '\0'); + s->reg[I_(UERSTAT)] |= UERSTAT_BREAK; + exynos4210_uart_update_irq(s); + } +} + + +static void exynos4210_uart_reset(DeviceState *dev) +{ + Exynos4210UartState *s = + container_of(dev, Exynos4210UartState, busdev.qdev); + int regs_number = sizeof(exynos4210_uart_regs)/sizeof(Exynos4210UartReg); + int i; + + for (i = 0; i < regs_number; i++) { + s->reg[I_(exynos4210_uart_regs[i].offset)] = + exynos4210_uart_regs[i].reset_value; + } + + fifo_reset(&s->rx); + fifo_reset(&s->tx); + + PRINT_DEBUG("UART%d: Rx FIFO size: %d\n", s->channel, s->rx.size); +} + +static const VMStateDescription vmstate_exynos4210_uart_fifo = { + .name = "exynos4210.uart.fifo", + .version_id = 1, + .minimum_version_id = 1, + .minimum_version_id_old = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(sp, Exynos4210UartFIFO), + VMSTATE_UINT32(rp, Exynos4210UartFIFO), + VMSTATE_VBUFFER_UINT32(data, Exynos4210UartFIFO, 1, NULL, 0, size), + VMSTATE_END_OF_LIST() + } +}; + +static const VMStateDescription vmstate_exynos4210_uart = { + .name = "exynos4210.uart", + .version_id = 1, + .minimum_version_id = 1, + .minimum_version_id_old = 1, + .fields = (VMStateField[]) { + VMSTATE_STRUCT(rx, Exynos4210UartState, 1, + vmstate_exynos4210_uart_fifo, Exynos4210UartFIFO), + VMSTATE_UINT32_ARRAY(reg, Exynos4210UartState, + EXYNOS4210_UART_REGS_MEM_SIZE / sizeof(uint32_t)), + VMSTATE_END_OF_LIST() + } +}; + +DeviceState *exynos4210_uart_create(hwaddr addr, + int fifo_size, + int channel, + CharDriverState *chr, + qemu_irq irq) +{ + DeviceState *dev; + SysBusDevice *bus; + + const char chr_name[] = "serial"; + char label[ARRAY_SIZE(chr_name) + 1]; + + dev = qdev_create(NULL, "exynos4210.uart"); + + if (!chr) { + if (channel >= MAX_SERIAL_PORTS) { + hw_error("Only %d serial ports are supported by QEMU.\n", + MAX_SERIAL_PORTS); + } + chr = serial_hds[channel]; + if (!chr) { + snprintf(label, ARRAY_SIZE(label), "%s%d", chr_name, channel); + chr = qemu_chr_new(label, "null", NULL); + if (!(chr)) { + hw_error("Can't assign serial port to UART%d.\n", channel); + } + } + } + + qdev_prop_set_chr(dev, "chardev", chr); + qdev_prop_set_uint32(dev, "channel", channel); + qdev_prop_set_uint32(dev, "rx-size", fifo_size); + qdev_prop_set_uint32(dev, "tx-size", fifo_size); + + bus = SYS_BUS_DEVICE(dev); + qdev_init_nofail(dev); + if (addr != (hwaddr)-1) { + sysbus_mmio_map(bus, 0, addr); + } + sysbus_connect_irq(bus, 0, irq); + + return dev; +} + +static int exynos4210_uart_init(SysBusDevice *dev) +{ + Exynos4210UartState *s = FROM_SYSBUS(Exynos4210UartState, dev); + + /* memory mapping */ + memory_region_init_io(&s->iomem, &exynos4210_uart_ops, s, "exynos4210.uart", + EXYNOS4210_UART_REGS_MEM_SIZE); + sysbus_init_mmio(dev, &s->iomem); + + sysbus_init_irq(dev, &s->irq); + + qemu_chr_add_handlers(s->chr, exynos4210_uart_can_receive, + exynos4210_uart_receive, exynos4210_uart_event, s); + + return 0; +} + +static Property exynos4210_uart_properties[] = { + DEFINE_PROP_CHR("chardev", Exynos4210UartState, chr), + DEFINE_PROP_UINT32("channel", Exynos4210UartState, channel, 0), + DEFINE_PROP_UINT32("rx-size", Exynos4210UartState, rx.size, 16), + DEFINE_PROP_UINT32("tx-size", Exynos4210UartState, tx.size, 16), + DEFINE_PROP_END_OF_LIST(), +}; + +static void exynos4210_uart_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass); + + k->init = exynos4210_uart_init; + dc->reset = exynos4210_uart_reset; + dc->props = exynos4210_uart_properties; + dc->vmsd = &vmstate_exynos4210_uart; +} + +static const TypeInfo exynos4210_uart_info = { + .name = "exynos4210.uart", + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(Exynos4210UartState), + .class_init = exynos4210_uart_class_init, +}; + +static void exynos4210_uart_register(void) +{ + type_register_static(&exynos4210_uart_info); +} + +type_init(exynos4210_uart_register) |