/* * Exynos4210 UART Emulation * * Copyright (C) 2011 Samsung Electronics Co Ltd. * Maksim Kozlov, * * 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 . * */ #include "qemu/osdep.h" #include "hw/sysbus.h" #include "migration/vmstate.h" #include "qapi/error.h" #include "qemu/error-report.h" #include "qemu/module.h" #include "qemu/timer.h" #include "chardev/char-fe.h" #include "chardev/char-serial.h" #include "hw/arm/exynos4210.h" #include "hw/irq.h" #include "hw/qdev-properties.h" #include "hw/qdev-properties-system.h" #include "trace.h" #include "qom/object.h" /* * 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 const 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_Rx_TIMEOUT 0x8 #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; #define TYPE_EXYNOS4210_UART "exynos4210.uart" OBJECT_DECLARE_SIMPLE_TYPE(Exynos4210UartState, EXYNOS4210_UART) struct Exynos4210UartState { SysBusDevice parent_obj; MemoryRegion iomem; uint32_t reg[EXYNOS4210_UART_REGS_MEM_SIZE / sizeof(uint32_t)]; Exynos4210UartFIFO rx; Exynos4210UartFIFO tx; QEMUTimer *fifo_timeout_timer; uint64_t wordtime; /* word time in ns */ CharBackend chr; qemu_irq irq; qemu_irq dmairq; uint32_t channel; }; /* Used only for tracing */ static const char *exynos4210_uart_regname(hwaddr offset) { int i; for (i = 0; i < ARRAY_SIZE(exynos4210_uart_regs); i++) { if (offset == exynos4210_uart_regs[i].offset) { return exynos4210_uart_regs[i].name; } } return NULL; } 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(const 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(const Exynos4210UartFIFO *q) { return q->size - fifo_elements_number(q); } static void fifo_reset(Exynos4210UartFIFO *q) { 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_FIFO_trigger_level(uint32_t channel, uint32_t reg) { uint32_t level; switch (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; trace_exynos_uart_channel_error(channel); break; } return level; } static uint32_t exynos4210_uart_Tx_FIFO_trigger_level(const Exynos4210UartState *s) { uint32_t reg; reg = (s->reg[I_(UFCON)] & UFCON_Tx_FIFO_TRIGGER_LEVEL) >> UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT; return exynos4210_uart_FIFO_trigger_level(s->channel, reg); } static uint32_t exynos4210_uart_Rx_FIFO_trigger_level(const Exynos4210UartState *s) { uint32_t reg; reg = ((s->reg[I_(UFCON)] & UFCON_Rx_FIFO_TRIGGER_LEVEL) >> UFCON_Rx_FIFO_TRIGGER_LEVEL_SHIFT) + 1; return exynos4210_uart_FIFO_trigger_level(s->channel, reg); } /* * Update Rx DMA busy signal if Rx DMA is enabled. For simplicity, * mark DMA as busy if DMA is enabled and the receive buffer is empty. */ static void exynos4210_uart_update_dmabusy(Exynos4210UartState *s) { bool rx_dma_enabled = (s->reg[I_(UCON)] & 0x03) == 0x02; uint32_t count = fifo_elements_number(&s->rx); if (rx_dma_enabled && !count) { qemu_irq_raise(s->dmairq); trace_exynos_uart_dmabusy(s->channel); } else { qemu_irq_lower(s->dmairq); trace_exynos_uart_dmaready(s->channel); } } 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; } /* * Rx interrupt if trigger level is reached or if rx timeout * interrupt is disabled and there is data in the receive buffer */ count = fifo_elements_number(&s->rx); if ((count && !(s->reg[I_(UCON)] & 0x80)) || count >= exynos4210_uart_Rx_FIFO_trigger_level(s)) { exynos4210_uart_update_dmabusy(s); s->reg[I_(UINTSP)] |= UINTSP_RXD; timer_del(s->fifo_timeout_timer); } } else if (s->reg[I_(UTRSTAT)] & UTRSTAT_Rx_BUFFER_DATA_READY) { exynos4210_uart_update_dmabusy(s); s->reg[I_(UINTSP)] |= UINTSP_RXD; } s->reg[I_(UINTP)] = s->reg[I_(UINTSP)] & ~s->reg[I_(UINTM)]; if (s->reg[I_(UINTP)]) { qemu_irq_raise(s->irq); trace_exynos_uart_irq_raised(s->channel, s->reg[I_(UINTP)]); } else { qemu_irq_lower(s->irq); trace_exynos_uart_irq_lowered(s->channel); } } static void exynos4210_uart_timeout_int(void *opaque) { Exynos4210UartState *s = opaque; trace_exynos_uart_rx_timeout(s->channel, s->reg[I_(UTRSTAT)], s->reg[I_(UINTSP)]); if ((s->reg[I_(UTRSTAT)] & UTRSTAT_Rx_BUFFER_DATA_READY) || (s->reg[I_(UCON)] & (1 << 11))) { s->reg[I_(UINTSP)] |= UINTSP_RXD; s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_TIMEOUT; exynos4210_uart_update_dmabusy(s); exynos4210_uart_update_irq(s); } } static void exynos4210_uart_update_parameters(Exynos4210UartState *s) { int speed, parity, data_bits, stop_bits; QEMUSerialSetParams ssp; uint64_t uclk_rate; if (s->reg[I_(UBRDIV)] == 0) { return; } if (s->reg[I_(ULCON)] & 0x20) { 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; 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; s->wordtime = NANOSECONDS_PER_SECOND * (data_bits + stop_bits + 1) / speed; qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); trace_exynos_uart_update_params( s->channel, speed, parity, data_bits, stop_bits, s->wordtime); } static void exynos4210_uart_rx_timeout_set(Exynos4210UartState *s) { if (s->reg[I_(UCON)] & 0x80) { uint32_t timeout = ((s->reg[I_(UCON)] >> 12) & 0x0f) * s->wordtime; timer_mod(s->fifo_timeout_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + timeout); } else { timer_del(s->fifo_timeout_timer); } } static void exynos4210_uart_write(void *opaque, hwaddr offset, uint64_t val, unsigned size) { Exynos4210UartState *s = (Exynos4210UartState *)opaque; uint8_t ch; trace_exynos_uart_write(s->channel, offset, exynos4210_uart_regname(offset), 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; trace_exynos_uart_rx_fifo_reset(s->channel); } if (val & UFCON_Tx_FIFO_RESET) { fifo_reset(&s->tx); s->reg[I_(UFCON)] &= ~UFCON_Tx_FIFO_RESET; trace_exynos_uart_tx_fifo_reset(s->channel); } break; case UTXH: if (qemu_chr_fe_backend_connected(&s->chr)) { s->reg[I_(UTRSTAT)] &= ~(UTRSTAT_TRANSMITTER_EMPTY | UTRSTAT_Tx_BUFFER_EMPTY); ch = (uint8_t)val; /* XXX this blocks entire thread. Rewrite to use * qemu_chr_fe_write and background I/O callbacks */ qemu_chr_fe_write_all(&s->chr, &ch, 1); trace_exynos_uart_tx(s->channel, ch); 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; trace_exynos_uart_intclr(s->channel, s->reg[I_(UINTP)]); exynos4210_uart_update_irq(s); break; case UTRSTAT: if (val & UTRSTAT_Rx_TIMEOUT) { s->reg[I_(UTRSTAT)] &= ~UTRSTAT_Rx_TIMEOUT; } break; case UERSTAT: case UFSTAT: case UMSTAT: case URXH: trace_exynos_uart_ro_write( 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; trace_exynos_uart_read(s->channel, offset, exynos4210_uart_regname(offset), res); 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; } trace_exynos_uart_read(s->channel, offset, exynos4210_uart_regname(offset), s->reg[I_(UFSTAT)]); 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); trace_exynos_uart_rx(s->channel, res); 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 { trace_exynos_uart_rx_error(s->channel); 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)]; } exynos4210_uart_update_dmabusy(s); trace_exynos_uart_read(s->channel, offset, exynos4210_uart_regname(offset), res); return res; case UTXH: trace_exynos_uart_wo_read(s->channel, exynos4210_uart_regname(offset), offset); break; default: trace_exynos_uart_read(s->channel, offset, exynos4210_uart_regname(offset), s->reg[I_(offset)]); return s->reg[I_(offset)]; } trace_exynos_uart_read(s->channel, offset, exynos4210_uart_regname(offset), 0); 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; if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) { return fifo_empty_elements_number(&s->rx); } else { return !(s->reg[I_(UTRSTAT)] & UTRSTAT_Rx_BUFFER_DATA_READY); } } 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) { size = fifo_empty_elements_number(&s->rx); s->reg[I_(UINTSP)] |= UINTSP_ERROR; } for (i = 0; i < size; i++) { fifo_store(&s->rx, buf[i]); } exynos4210_uart_rx_timeout_set(s); } else { s->reg[I_(URXH)] = buf[0]; } s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY; exynos4210_uart_update_irq(s); } static void exynos4210_uart_event(void *opaque, QEMUChrEvent 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 = EXYNOS4210_UART(dev); int i; for (i = 0; i < ARRAY_SIZE(exynos4210_uart_regs); i++) { s->reg[I_(exynos4210_uart_regs[i].offset)] = exynos4210_uart_regs[i].reset_value; } fifo_reset(&s->rx); fifo_reset(&s->tx); trace_exynos_uart_rxsize(s->channel, s->rx.size); } static int exynos4210_uart_post_load(void *opaque, int version_id) { Exynos4210UartState *s = (Exynos4210UartState *)opaque; exynos4210_uart_update_parameters(s); exynos4210_uart_rx_timeout_set(s); return 0; } static const VMStateDescription vmstate_exynos4210_uart_fifo = { .name = "exynos4210.uart.fifo", .version_id = 1, .minimum_version_id = 1, .post_load = exynos4210_uart_post_load, .fields = (VMStateField[]) { VMSTATE_UINT32(sp, Exynos4210UartFIFO), VMSTATE_UINT32(rp, Exynos4210UartFIFO), VMSTATE_VBUFFER_UINT32(data, Exynos4210UartFIFO, 1, NULL, size), VMSTATE_END_OF_LIST() } }; static const VMStateDescription vmstate_exynos4210_uart = { .name = "exynos4210.uart", .version_id = 1, .minimum_version_id = 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, Chardev *chr, qemu_irq irq) { DeviceState *dev; SysBusDevice *bus; dev = qdev_new(TYPE_EXYNOS4210_UART); 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); sysbus_realize_and_unref(bus, &error_fatal); if (addr != (hwaddr)-1) { sysbus_mmio_map(bus, 0, addr); } sysbus_connect_irq(bus, 0, irq); return dev; } static void exynos4210_uart_init(Object *obj) { SysBusDevice *dev = SYS_BUS_DEVICE(obj); Exynos4210UartState *s = EXYNOS4210_UART(dev); s->wordtime = NANOSECONDS_PER_SECOND * 10 / 9600; /* memory mapping */ memory_region_init_io(&s->iomem, obj, &exynos4210_uart_ops, s, "exynos4210.uart", EXYNOS4210_UART_REGS_MEM_SIZE); sysbus_init_mmio(dev, &s->iomem); sysbus_init_irq(dev, &s->irq); sysbus_init_irq(dev, &s->dmairq); } static void exynos4210_uart_realize(DeviceState *dev, Error **errp) { Exynos4210UartState *s = EXYNOS4210_UART(dev); s->fifo_timeout_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, exynos4210_uart_timeout_int, s); qemu_chr_fe_set_handlers(&s->chr, exynos4210_uart_can_receive, exynos4210_uart_receive, exynos4210_uart_event, NULL, s, NULL, true); } 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); dc->realize = exynos4210_uart_realize; dc->reset = exynos4210_uart_reset; device_class_set_props(dc, exynos4210_uart_properties); dc->vmsd = &vmstate_exynos4210_uart; } static const TypeInfo exynos4210_uart_info = { .name = TYPE_EXYNOS4210_UART, .parent = TYPE_SYS_BUS_DEVICE, .instance_size = sizeof(Exynos4210UartState), .instance_init = exynos4210_uart_init, .class_init = exynos4210_uart_class_init, }; static void exynos4210_uart_register(void) { type_register_static(&exynos4210_uart_info); } type_init(exynos4210_uart_register)