2 * Exynos4210 UART Emulation
4 * Copyright (C) 2011 Samsung Electronics Co Ltd.
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, see <http://www.gnu.org/licenses/>.
22 #include "qemu/osdep.h"
23 #include "hw/sysbus.h"
24 #include "qemu/error-report.h"
25 #include "sysemu/sysemu.h"
26 #include "chardev/char-fe.h"
27 #include "chardev/char-serial.h"
29 #include "hw/arm/exynos4210.h"
32 #undef DEBUG_UART_EXTEND
38 #define DEBUG_UART_EXTEND 0
40 #define DEBUG_Rx_DATA 0
41 #define DEBUG_Tx_DATA 0
44 #define PRINT_DEBUG(fmt, args...) \
46 fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \
50 #define PRINT_DEBUG_EXTEND(fmt, args...) \
52 fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \
55 #define PRINT_DEBUG_EXTEND(fmt, args...) \
60 #define PRINT_DEBUG(fmt, args...) \
62 #define PRINT_DEBUG_EXTEND(fmt, args...) \
66 #define PRINT_ERROR(fmt, args...) \
68 fprintf(stderr, " [%s:%d] "fmt, __func__, __LINE__, ##args); \
72 * Offsets for UART registers relative to SFR base address
76 #define ULCON 0x0000 /* Line Control */
77 #define UCON 0x0004 /* Control */
78 #define UFCON 0x0008 /* FIFO Control */
79 #define UMCON 0x000C /* Modem Control */
80 #define UTRSTAT 0x0010 /* Tx/Rx Status */
81 #define UERSTAT 0x0014 /* UART Error Status */
82 #define UFSTAT 0x0018 /* FIFO Status */
83 #define UMSTAT 0x001C /* Modem Status */
84 #define UTXH 0x0020 /* Transmit Buffer */
85 #define URXH 0x0024 /* Receive Buffer */
86 #define UBRDIV 0x0028 /* Baud Rate Divisor */
87 #define UFRACVAL 0x002C /* Divisor Fractional Value */
88 #define UINTP 0x0030 /* Interrupt Pending */
89 #define UINTSP 0x0034 /* Interrupt Source Pending */
90 #define UINTM 0x0038 /* Interrupt Mask */
93 * for indexing register in the uint32_t array
95 * 'reg' - register offset (see offsets definitions above)
98 #define I_(reg) (reg / sizeof(uint32_t))
100 typedef struct Exynos4210UartReg {
101 const char *name; /* the only reason is the debug output */
103 uint32_t reset_value;
106 static const Exynos4210UartReg exynos4210_uart_regs[] = {
107 {"ULCON", ULCON, 0x00000000},
108 {"UCON", UCON, 0x00003000},
109 {"UFCON", UFCON, 0x00000000},
110 {"UMCON", UMCON, 0x00000000},
111 {"UTRSTAT", UTRSTAT, 0x00000006}, /* RO */
112 {"UERSTAT", UERSTAT, 0x00000000}, /* RO */
113 {"UFSTAT", UFSTAT, 0x00000000}, /* RO */
114 {"UMSTAT", UMSTAT, 0x00000000}, /* RO */
115 {"UTXH", UTXH, 0x5c5c5c5c}, /* WO, undefined reset value*/
116 {"URXH", URXH, 0x00000000}, /* RO */
117 {"UBRDIV", UBRDIV, 0x00000000},
118 {"UFRACVAL", UFRACVAL, 0x00000000},
119 {"UINTP", UINTP, 0x00000000},
120 {"UINTSP", UINTSP, 0x00000000},
121 {"UINTM", UINTM, 0x00000000},
124 #define EXYNOS4210_UART_REGS_MEM_SIZE 0x3C
126 /* UART FIFO Control */
127 #define UFCON_FIFO_ENABLE 0x1
128 #define UFCON_Rx_FIFO_RESET 0x2
129 #define UFCON_Tx_FIFO_RESET 0x4
130 #define UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT 8
131 #define UFCON_Tx_FIFO_TRIGGER_LEVEL (7 << UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT)
132 #define UFCON_Rx_FIFO_TRIGGER_LEVEL_SHIFT 4
133 #define UFCON_Rx_FIFO_TRIGGER_LEVEL (7 << UFCON_Rx_FIFO_TRIGGER_LEVEL_SHIFT)
135 /* Uart FIFO Status */
136 #define UFSTAT_Rx_FIFO_COUNT 0xff
137 #define UFSTAT_Rx_FIFO_FULL 0x100
138 #define UFSTAT_Rx_FIFO_ERROR 0x200
139 #define UFSTAT_Tx_FIFO_COUNT_SHIFT 16
140 #define UFSTAT_Tx_FIFO_COUNT (0xff << UFSTAT_Tx_FIFO_COUNT_SHIFT)
141 #define UFSTAT_Tx_FIFO_FULL_SHIFT 24
142 #define UFSTAT_Tx_FIFO_FULL (1 << UFSTAT_Tx_FIFO_FULL_SHIFT)
144 /* UART Interrupt Source Pending */
145 #define UINTSP_RXD 0x1 /* Receive interrupt */
146 #define UINTSP_ERROR 0x2 /* Error interrupt */
147 #define UINTSP_TXD 0x4 /* Transmit interrupt */
148 #define UINTSP_MODEM 0x8 /* Modem interrupt */
150 /* UART Line Control */
151 #define ULCON_IR_MODE_SHIFT 6
152 #define ULCON_PARITY_SHIFT 3
153 #define ULCON_STOP_BIT_SHIFT 1
155 /* UART Tx/Rx Status */
156 #define UTRSTAT_TRANSMITTER_EMPTY 0x4
157 #define UTRSTAT_Tx_BUFFER_EMPTY 0x2
158 #define UTRSTAT_Rx_BUFFER_DATA_READY 0x1
160 /* UART Error Status */
161 #define UERSTAT_OVERRUN 0x1
162 #define UERSTAT_PARITY 0x2
163 #define UERSTAT_FRAME 0x4
164 #define UERSTAT_BREAK 0x8
168 uint32_t sp, rp; /* store and retrieve pointers */
170 } Exynos4210UartFIFO;
172 #define TYPE_EXYNOS4210_UART "exynos4210.uart"
173 #define EXYNOS4210_UART(obj) \
174 OBJECT_CHECK(Exynos4210UartState, (obj), TYPE_EXYNOS4210_UART)
176 typedef struct Exynos4210UartState {
177 SysBusDevice parent_obj;
181 uint32_t reg[EXYNOS4210_UART_REGS_MEM_SIZE / sizeof(uint32_t)];
182 Exynos4210UartFIFO rx;
183 Exynos4210UartFIFO tx;
190 } Exynos4210UartState;
194 /* Used only for debugging inside PRINT_DEBUG_... macros */
195 static const char *exynos4210_uart_regname(hwaddr offset)
200 for (i = 0; i < ARRAY_SIZE(exynos4210_uart_regs); i++) {
201 if (offset == exynos4210_uart_regs[i].offset) {
202 return exynos4210_uart_regs[i].name;
211 static void fifo_store(Exynos4210UartFIFO *q, uint8_t ch)
214 q->sp = (q->sp + 1) % q->size;
217 static uint8_t fifo_retrieve(Exynos4210UartFIFO *q)
219 uint8_t ret = q->data[q->rp];
220 q->rp = (q->rp + 1) % q->size;
224 static int fifo_elements_number(const Exynos4210UartFIFO *q)
227 return q->size - q->rp + q->sp;
230 return q->sp - q->rp;
233 static int fifo_empty_elements_number(const Exynos4210UartFIFO *q)
235 return q->size - fifo_elements_number(q);
238 static void fifo_reset(Exynos4210UartFIFO *q)
243 q->data = (uint8_t *)g_malloc0(q->size);
249 static uint32_t exynos4210_uart_Tx_FIFO_trigger_level(const Exynos4210UartState *s)
254 reg = (s->reg[I_(UFCON)] & UFCON_Tx_FIFO_TRIGGER_LEVEL) >>
255 UFCON_Tx_FIFO_TRIGGER_LEVEL_SHIFT;
257 switch (s->channel) {
271 PRINT_ERROR("Wrong UART channel number: %d\n", s->channel);
277 static void exynos4210_uart_update_irq(Exynos4210UartState *s)
280 * The Tx interrupt is always requested if the number of data in the
281 * transmit FIFO is smaller than the trigger level.
283 if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) {
285 uint32_t count = (s->reg[I_(UFSTAT)] & UFSTAT_Tx_FIFO_COUNT) >>
286 UFSTAT_Tx_FIFO_COUNT_SHIFT;
288 if (count <= exynos4210_uart_Tx_FIFO_trigger_level(s)) {
289 s->reg[I_(UINTSP)] |= UINTSP_TXD;
293 s->reg[I_(UINTP)] = s->reg[I_(UINTSP)] & ~s->reg[I_(UINTM)];
295 if (s->reg[I_(UINTP)]) {
296 qemu_irq_raise(s->irq);
299 fprintf(stderr, "UART%d: IRQ has been raised: %08x\n",
300 s->channel, s->reg[I_(UINTP)]);
304 qemu_irq_lower(s->irq);
308 static void exynos4210_uart_update_parameters(Exynos4210UartState *s)
310 int speed, parity, data_bits, stop_bits;
311 QEMUSerialSetParams ssp;
314 if (s->reg[I_(UBRDIV)] == 0) {
318 if (s->reg[I_(ULCON)] & 0x20) {
319 if (s->reg[I_(ULCON)] & 0x28) {
328 if (s->reg[I_(ULCON)] & 0x4) {
334 data_bits = (s->reg[I_(ULCON)] & 0x3) + 5;
336 uclk_rate = 24000000;
338 speed = uclk_rate / ((16 * (s->reg[I_(UBRDIV)]) & 0xffff) +
339 (s->reg[I_(UFRACVAL)] & 0x7) + 16);
343 ssp.data_bits = data_bits;
344 ssp.stop_bits = stop_bits;
346 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
348 PRINT_DEBUG("UART%d: speed: %d, parity: %c, data: %d, stop: %d\n",
349 s->channel, speed, parity, data_bits, stop_bits);
352 static void exynos4210_uart_write(void *opaque, hwaddr offset,
353 uint64_t val, unsigned size)
355 Exynos4210UartState *s = (Exynos4210UartState *)opaque;
358 PRINT_DEBUG_EXTEND("UART%d: <0x%04x> %s <- 0x%08llx\n", s->channel,
359 offset, exynos4210_uart_regname(offset), (long long unsigned int)val);
365 s->reg[I_(offset)] = val;
366 exynos4210_uart_update_parameters(s);
369 s->reg[I_(UFCON)] = val;
370 if (val & UFCON_Rx_FIFO_RESET) {
372 s->reg[I_(UFCON)] &= ~UFCON_Rx_FIFO_RESET;
373 PRINT_DEBUG("UART%d: Rx FIFO Reset\n", s->channel);
375 if (val & UFCON_Tx_FIFO_RESET) {
377 s->reg[I_(UFCON)] &= ~UFCON_Tx_FIFO_RESET;
378 PRINT_DEBUG("UART%d: Tx FIFO Reset\n", s->channel);
383 if (qemu_chr_fe_backend_connected(&s->chr)) {
384 s->reg[I_(UTRSTAT)] &= ~(UTRSTAT_TRANSMITTER_EMPTY |
385 UTRSTAT_Tx_BUFFER_EMPTY);
387 /* XXX this blocks entire thread. Rewrite to use
388 * qemu_chr_fe_write and background I/O callbacks */
389 qemu_chr_fe_write_all(&s->chr, &ch, 1);
391 fprintf(stderr, "%c", ch);
393 s->reg[I_(UTRSTAT)] |= UTRSTAT_TRANSMITTER_EMPTY |
394 UTRSTAT_Tx_BUFFER_EMPTY;
395 s->reg[I_(UINTSP)] |= UINTSP_TXD;
396 exynos4210_uart_update_irq(s);
401 s->reg[I_(UINTP)] &= ~val;
402 s->reg[I_(UINTSP)] &= ~val;
403 PRINT_DEBUG("UART%d: UINTP [%04x] have been cleared: %08x\n",
404 s->channel, offset, s->reg[I_(UINTP)]);
405 exynos4210_uart_update_irq(s);
412 PRINT_DEBUG("UART%d: Trying to write into RO register: %s [%04x]\n",
413 s->channel, exynos4210_uart_regname(offset), offset);
416 s->reg[I_(UINTSP)] &= ~val;
419 s->reg[I_(UINTM)] = val;
420 exynos4210_uart_update_irq(s);
425 s->reg[I_(offset)] = val;
429 static uint64_t exynos4210_uart_read(void *opaque, hwaddr offset,
432 Exynos4210UartState *s = (Exynos4210UartState *)opaque;
436 case UERSTAT: /* Read Only */
437 res = s->reg[I_(UERSTAT)];
438 s->reg[I_(UERSTAT)] = 0;
440 case UFSTAT: /* Read Only */
441 s->reg[I_(UFSTAT)] = fifo_elements_number(&s->rx) & 0xff;
442 if (fifo_empty_elements_number(&s->rx) == 0) {
443 s->reg[I_(UFSTAT)] |= UFSTAT_Rx_FIFO_FULL;
444 s->reg[I_(UFSTAT)] &= ~0xff;
446 return s->reg[I_(UFSTAT)];
448 if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) {
449 if (fifo_elements_number(&s->rx)) {
450 res = fifo_retrieve(&s->rx);
452 fprintf(stderr, "%c", res);
454 if (!fifo_elements_number(&s->rx)) {
455 s->reg[I_(UTRSTAT)] &= ~UTRSTAT_Rx_BUFFER_DATA_READY;
457 s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY;
460 s->reg[I_(UINTSP)] |= UINTSP_ERROR;
461 exynos4210_uart_update_irq(s);
465 s->reg[I_(UTRSTAT)] &= ~UTRSTAT_Rx_BUFFER_DATA_READY;
466 res = s->reg[I_(URXH)];
470 PRINT_DEBUG("UART%d: Trying to read from WO register: %s [%04x]\n",
471 s->channel, exynos4210_uart_regname(offset), offset);
474 return s->reg[I_(offset)];
480 static const MemoryRegionOps exynos4210_uart_ops = {
481 .read = exynos4210_uart_read,
482 .write = exynos4210_uart_write,
483 .endianness = DEVICE_NATIVE_ENDIAN,
485 .max_access_size = 4,
490 static int exynos4210_uart_can_receive(void *opaque)
492 Exynos4210UartState *s = (Exynos4210UartState *)opaque;
494 return fifo_empty_elements_number(&s->rx);
498 static void exynos4210_uart_receive(void *opaque, const uint8_t *buf, int size)
500 Exynos4210UartState *s = (Exynos4210UartState *)opaque;
503 if (s->reg[I_(UFCON)] & UFCON_FIFO_ENABLE) {
504 if (fifo_empty_elements_number(&s->rx) < size) {
505 for (i = 0; i < fifo_empty_elements_number(&s->rx); i++) {
506 fifo_store(&s->rx, buf[i]);
508 s->reg[I_(UINTSP)] |= UINTSP_ERROR;
509 s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY;
511 for (i = 0; i < size; i++) {
512 fifo_store(&s->rx, buf[i]);
514 s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY;
516 /* XXX: Around here we maybe should check Rx trigger level */
517 s->reg[I_(UINTSP)] |= UINTSP_RXD;
519 s->reg[I_(URXH)] = buf[0];
520 s->reg[I_(UINTSP)] |= UINTSP_RXD;
521 s->reg[I_(UTRSTAT)] |= UTRSTAT_Rx_BUFFER_DATA_READY;
524 exynos4210_uart_update_irq(s);
528 static void exynos4210_uart_event(void *opaque, int event)
530 Exynos4210UartState *s = (Exynos4210UartState *)opaque;
532 if (event == CHR_EVENT_BREAK) {
533 /* When the RxDn is held in logic 0, then a null byte is pushed into the
535 fifo_store(&s->rx, '\0');
536 s->reg[I_(UERSTAT)] |= UERSTAT_BREAK;
537 exynos4210_uart_update_irq(s);
542 static void exynos4210_uart_reset(DeviceState *dev)
544 Exynos4210UartState *s = EXYNOS4210_UART(dev);
547 for (i = 0; i < ARRAY_SIZE(exynos4210_uart_regs); i++) {
548 s->reg[I_(exynos4210_uart_regs[i].offset)] =
549 exynos4210_uart_regs[i].reset_value;
555 PRINT_DEBUG("UART%d: Rx FIFO size: %d\n", s->channel, s->rx.size);
558 static const VMStateDescription vmstate_exynos4210_uart_fifo = {
559 .name = "exynos4210.uart.fifo",
561 .minimum_version_id = 1,
562 .fields = (VMStateField[]) {
563 VMSTATE_UINT32(sp, Exynos4210UartFIFO),
564 VMSTATE_UINT32(rp, Exynos4210UartFIFO),
565 VMSTATE_VBUFFER_UINT32(data, Exynos4210UartFIFO, 1, NULL, size),
566 VMSTATE_END_OF_LIST()
570 static const VMStateDescription vmstate_exynos4210_uart = {
571 .name = "exynos4210.uart",
573 .minimum_version_id = 1,
574 .fields = (VMStateField[]) {
575 VMSTATE_STRUCT(rx, Exynos4210UartState, 1,
576 vmstate_exynos4210_uart_fifo, Exynos4210UartFIFO),
577 VMSTATE_UINT32_ARRAY(reg, Exynos4210UartState,
578 EXYNOS4210_UART_REGS_MEM_SIZE / sizeof(uint32_t)),
579 VMSTATE_END_OF_LIST()
583 DeviceState *exynos4210_uart_create(hwaddr addr,
592 dev = qdev_create(NULL, TYPE_EXYNOS4210_UART);
594 qdev_prop_set_chr(dev, "chardev", chr);
595 qdev_prop_set_uint32(dev, "channel", channel);
596 qdev_prop_set_uint32(dev, "rx-size", fifo_size);
597 qdev_prop_set_uint32(dev, "tx-size", fifo_size);
599 bus = SYS_BUS_DEVICE(dev);
600 qdev_init_nofail(dev);
601 if (addr != (hwaddr)-1) {
602 sysbus_mmio_map(bus, 0, addr);
604 sysbus_connect_irq(bus, 0, irq);
609 static void exynos4210_uart_init(Object *obj)
611 SysBusDevice *dev = SYS_BUS_DEVICE(obj);
612 Exynos4210UartState *s = EXYNOS4210_UART(dev);
615 memory_region_init_io(&s->iomem, obj, &exynos4210_uart_ops, s,
616 "exynos4210.uart", EXYNOS4210_UART_REGS_MEM_SIZE);
617 sysbus_init_mmio(dev, &s->iomem);
619 sysbus_init_irq(dev, &s->irq);
622 static void exynos4210_uart_realize(DeviceState *dev, Error **errp)
624 Exynos4210UartState *s = EXYNOS4210_UART(dev);
626 qemu_chr_fe_set_handlers(&s->chr, exynos4210_uart_can_receive,
627 exynos4210_uart_receive, exynos4210_uart_event,
628 NULL, s, NULL, true);
631 static Property exynos4210_uart_properties[] = {
632 DEFINE_PROP_CHR("chardev", Exynos4210UartState, chr),
633 DEFINE_PROP_UINT32("channel", Exynos4210UartState, channel, 0),
634 DEFINE_PROP_UINT32("rx-size", Exynos4210UartState, rx.size, 16),
635 DEFINE_PROP_UINT32("tx-size", Exynos4210UartState, tx.size, 16),
636 DEFINE_PROP_END_OF_LIST(),
639 static void exynos4210_uart_class_init(ObjectClass *klass, void *data)
641 DeviceClass *dc = DEVICE_CLASS(klass);
643 dc->realize = exynos4210_uart_realize;
644 dc->reset = exynos4210_uart_reset;
645 dc->props = exynos4210_uart_properties;
646 dc->vmsd = &vmstate_exynos4210_uart;
649 static const TypeInfo exynos4210_uart_info = {
650 .name = TYPE_EXYNOS4210_UART,
651 .parent = TYPE_SYS_BUS_DEVICE,
652 .instance_size = sizeof(Exynos4210UartState),
653 .instance_init = exynos4210_uart_init,
654 .class_init = exynos4210_uart_class_init,
657 static void exynos4210_uart_register(void)
659 type_register_static(&exynos4210_uart_info);
662 type_init(exynos4210_uart_register)