2 * Device model for Cadence UART
4 * Reference: Xilinx Zynq 7000 reference manual
5 * - http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf
6 * - Chapter 19 UART Controller
7 * - Appendix B for Register details
9 * Copyright (c) 2010 Xilinx Inc.
11 * Copyright (c) 2012 PetaLogix Pty Ltd.
12 * Written by Haibing Ma
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, see <http://www.gnu.org/licenses/>.
24 #include "qemu/osdep.h"
25 #include "hw/sysbus.h"
26 #include "sysemu/char.h"
27 #include "qemu/timer.h"
29 #include "hw/char/cadence_uart.h"
31 #ifdef CADENCE_UART_ERR_DEBUG
32 #define DB_PRINT(...) do { \
33 fprintf(stderr, ": %s: ", __func__); \
34 fprintf(stderr, ## __VA_ARGS__); \
40 #define UART_SR_INTR_RTRIG 0x00000001
41 #define UART_SR_INTR_REMPTY 0x00000002
42 #define UART_SR_INTR_RFUL 0x00000004
43 #define UART_SR_INTR_TEMPTY 0x00000008
44 #define UART_SR_INTR_TFUL 0x00000010
45 /* somewhat awkwardly, TTRIG is misaligned between SR and ISR */
46 #define UART_SR_TTRIG 0x00002000
47 #define UART_INTR_TTRIG 0x00000400
48 /* bits fields in CSR that correlate to CISR. If any of these bits are set in
49 * SR, then the same bit in CISR is set high too */
50 #define UART_SR_TO_CISR_MASK 0x0000001F
52 #define UART_INTR_ROVR 0x00000020
53 #define UART_INTR_FRAME 0x00000040
54 #define UART_INTR_PARE 0x00000080
55 #define UART_INTR_TIMEOUT 0x00000100
56 #define UART_INTR_DMSI 0x00000200
57 #define UART_INTR_TOVR 0x00001000
59 #define UART_SR_RACTIVE 0x00000400
60 #define UART_SR_TACTIVE 0x00000800
61 #define UART_SR_FDELT 0x00001000
63 #define UART_CR_RXRST 0x00000001
64 #define UART_CR_TXRST 0x00000002
65 #define UART_CR_RX_EN 0x00000004
66 #define UART_CR_RX_DIS 0x00000008
67 #define UART_CR_TX_EN 0x00000010
68 #define UART_CR_TX_DIS 0x00000020
69 #define UART_CR_RST_TO 0x00000040
70 #define UART_CR_STARTBRK 0x00000080
71 #define UART_CR_STOPBRK 0x00000100
73 #define UART_MR_CLKS 0x00000001
74 #define UART_MR_CHRL 0x00000006
75 #define UART_MR_CHRL_SH 1
76 #define UART_MR_PAR 0x00000038
77 #define UART_MR_PAR_SH 3
78 #define UART_MR_NBSTOP 0x000000C0
79 #define UART_MR_NBSTOP_SH 6
80 #define UART_MR_CHMODE 0x00000300
81 #define UART_MR_CHMODE_SH 8
82 #define UART_MR_UCLKEN 0x00000400
83 #define UART_MR_IRMODE 0x00000800
85 #define UART_DATA_BITS_6 (0x3 << UART_MR_CHRL_SH)
86 #define UART_DATA_BITS_7 (0x2 << UART_MR_CHRL_SH)
87 #define UART_PARITY_ODD (0x1 << UART_MR_PAR_SH)
88 #define UART_PARITY_EVEN (0x0 << UART_MR_PAR_SH)
89 #define UART_STOP_BITS_1 (0x3 << UART_MR_NBSTOP_SH)
90 #define UART_STOP_BITS_2 (0x2 << UART_MR_NBSTOP_SH)
91 #define NORMAL_MODE (0x0 << UART_MR_CHMODE_SH)
92 #define ECHO_MODE (0x1 << UART_MR_CHMODE_SH)
93 #define LOCAL_LOOPBACK (0x2 << UART_MR_CHMODE_SH)
94 #define REMOTE_LOOPBACK (0x3 << UART_MR_CHMODE_SH)
96 #define UART_INPUT_CLK 50000000
100 #define R_IER (0x08/4)
101 #define R_IDR (0x0C/4)
102 #define R_IMR (0x10/4)
103 #define R_CISR (0x14/4)
104 #define R_BRGR (0x18/4)
105 #define R_RTOR (0x1C/4)
106 #define R_RTRIG (0x20/4)
107 #define R_MCR (0x24/4)
108 #define R_MSR (0x28/4)
109 #define R_SR (0x2C/4)
110 #define R_TX_RX (0x30/4)
111 #define R_BDIV (0x34/4)
112 #define R_FDEL (0x38/4)
113 #define R_PMIN (0x3C/4)
114 #define R_PWID (0x40/4)
115 #define R_TTRIG (0x44/4)
118 static void uart_update_status(CadenceUARTState *s)
122 s->r[R_SR] |= s->rx_count == CADENCE_UART_RX_FIFO_SIZE ? UART_SR_INTR_RFUL
124 s->r[R_SR] |= !s->rx_count ? UART_SR_INTR_REMPTY : 0;
125 s->r[R_SR] |= s->rx_count >= s->r[R_RTRIG] ? UART_SR_INTR_RTRIG : 0;
127 s->r[R_SR] |= s->tx_count == CADENCE_UART_TX_FIFO_SIZE ? UART_SR_INTR_TFUL
129 s->r[R_SR] |= !s->tx_count ? UART_SR_INTR_TEMPTY : 0;
130 s->r[R_SR] |= s->tx_count >= s->r[R_TTRIG] ? UART_SR_TTRIG : 0;
132 s->r[R_CISR] |= s->r[R_SR] & UART_SR_TO_CISR_MASK;
133 s->r[R_CISR] |= s->r[R_SR] & UART_SR_TTRIG ? UART_INTR_TTRIG : 0;
134 qemu_set_irq(s->irq, !!(s->r[R_IMR] & s->r[R_CISR]));
137 static void fifo_trigger_update(void *opaque)
139 CadenceUARTState *s = opaque;
142 s->r[R_CISR] |= UART_INTR_TIMEOUT;
143 uart_update_status(s);
147 static void uart_rx_reset(CadenceUARTState *s)
151 qemu_chr_fe_accept_input(&s->chr);
154 static void uart_tx_reset(CadenceUARTState *s)
159 static void uart_send_breaks(CadenceUARTState *s)
161 int break_enabled = 1;
163 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_BREAK,
167 static void uart_parameters_setup(CadenceUARTState *s)
169 QEMUSerialSetParams ssp;
170 unsigned int baud_rate, packet_size;
172 baud_rate = (s->r[R_MR] & UART_MR_CLKS) ?
173 UART_INPUT_CLK / 8 : UART_INPUT_CLK;
175 ssp.speed = baud_rate / (s->r[R_BRGR] * (s->r[R_BDIV] + 1));
178 switch (s->r[R_MR] & UART_MR_PAR) {
179 case UART_PARITY_EVEN:
183 case UART_PARITY_ODD:
192 switch (s->r[R_MR] & UART_MR_CHRL) {
193 case UART_DATA_BITS_6:
196 case UART_DATA_BITS_7:
204 switch (s->r[R_MR] & UART_MR_NBSTOP) {
205 case UART_STOP_BITS_1:
213 packet_size += ssp.data_bits + ssp.stop_bits;
214 s->char_tx_time = (NANOSECONDS_PER_SECOND / ssp.speed) * packet_size;
215 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
218 static int uart_can_receive(void *opaque)
220 CadenceUARTState *s = opaque;
221 int ret = MAX(CADENCE_UART_RX_FIFO_SIZE, CADENCE_UART_TX_FIFO_SIZE);
222 uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
224 if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
225 ret = MIN(ret, CADENCE_UART_RX_FIFO_SIZE - s->rx_count);
227 if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) {
228 ret = MIN(ret, CADENCE_UART_TX_FIFO_SIZE - s->tx_count);
233 static void uart_ctrl_update(CadenceUARTState *s)
235 if (s->r[R_CR] & UART_CR_TXRST) {
239 if (s->r[R_CR] & UART_CR_RXRST) {
243 s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST);
245 if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) {
250 static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size)
252 CadenceUARTState *s = opaque;
253 uint64_t new_rx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
256 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) {
260 if (s->rx_count == CADENCE_UART_RX_FIFO_SIZE) {
261 s->r[R_CISR] |= UART_INTR_ROVR;
263 for (i = 0; i < size; i++) {
264 s->rx_fifo[s->rx_wpos] = buf[i];
265 s->rx_wpos = (s->rx_wpos + 1) % CADENCE_UART_RX_FIFO_SIZE;
268 timer_mod(s->fifo_trigger_handle, new_rx_time +
269 (s->char_tx_time * 4));
271 uart_update_status(s);
274 static gboolean cadence_uart_xmit(GIOChannel *chan, GIOCondition cond,
277 CadenceUARTState *s = opaque;
280 /* instant drain the fifo when there's no back-end */
281 if (!qemu_chr_fe_get_driver(&s->chr)) {
290 ret = qemu_chr_fe_write(&s->chr, s->tx_fifo, s->tx_count);
294 memmove(s->tx_fifo, s->tx_fifo + ret, s->tx_count);
298 guint r = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP,
299 cadence_uart_xmit, s);
306 uart_update_status(s);
310 static void uart_write_tx_fifo(CadenceUARTState *s, const uint8_t *buf,
313 if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) {
317 if (size > CADENCE_UART_TX_FIFO_SIZE - s->tx_count) {
318 size = CADENCE_UART_TX_FIFO_SIZE - s->tx_count;
320 * This can only be a guest error via a bad tx fifo register push,
321 * as can_receive() should stop remote loop and echo modes ever getting
324 qemu_log_mask(LOG_GUEST_ERROR, "cadence_uart: TxFIFO overflow");
325 s->r[R_CISR] |= UART_INTR_ROVR;
328 memcpy(s->tx_fifo + s->tx_count, buf, size);
331 cadence_uart_xmit(NULL, G_IO_OUT, s);
334 static void uart_receive(void *opaque, const uint8_t *buf, int size)
336 CadenceUARTState *s = opaque;
337 uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
339 if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
340 uart_write_rx_fifo(opaque, buf, size);
342 if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) {
343 uart_write_tx_fifo(s, buf, size);
347 static void uart_event(void *opaque, int event)
349 CadenceUARTState *s = opaque;
352 if (event == CHR_EVENT_BREAK) {
353 uart_write_rx_fifo(opaque, &buf, 1);
356 uart_update_status(s);
359 static void uart_read_rx_fifo(CadenceUARTState *s, uint32_t *c)
361 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) {
366 uint32_t rx_rpos = (CADENCE_UART_RX_FIFO_SIZE + s->rx_wpos -
367 s->rx_count) % CADENCE_UART_RX_FIFO_SIZE;
368 *c = s->rx_fifo[rx_rpos];
371 qemu_chr_fe_accept_input(&s->chr);
376 uart_update_status(s);
379 static void uart_write(void *opaque, hwaddr offset,
380 uint64_t value, unsigned size)
382 CadenceUARTState *s = opaque;
384 DB_PRINT(" offset:%x data:%08x\n", (unsigned)offset, (unsigned)value);
386 if (offset >= CADENCE_UART_R_MAX) {
390 case R_IER: /* ier (wts imr) */
391 s->r[R_IMR] |= value;
393 case R_IDR: /* idr (wtc imr) */
394 s->r[R_IMR] &= ~value;
396 case R_IMR: /* imr (read only) */
398 case R_CISR: /* cisr (wtc) */
399 s->r[R_CISR] &= ~value;
401 case R_TX_RX: /* UARTDR */
402 switch (s->r[R_MR] & UART_MR_CHMODE) {
404 uart_write_tx_fifo(s, (uint8_t *) &value, 1);
407 uart_write_rx_fifo(opaque, (uint8_t *) &value, 1);
411 case R_BRGR: /* Baud rate generator */
413 s->r[offset] = value & 0xFFFF;
416 case R_BDIV: /* Baud rate divider */
418 s->r[offset] = value & 0xFF;
422 s->r[offset] = value;
430 uart_parameters_setup(s);
433 uart_update_status(s);
436 static uint64_t uart_read(void *opaque, hwaddr offset,
439 CadenceUARTState *s = opaque;
443 if (offset >= CADENCE_UART_R_MAX) {
445 } else if (offset == R_TX_RX) {
446 uart_read_rx_fifo(s, &c);
451 DB_PRINT(" offset:%x data:%08x\n", (unsigned)(offset << 2), (unsigned)c);
455 static const MemoryRegionOps uart_ops = {
458 .endianness = DEVICE_NATIVE_ENDIAN,
461 static void cadence_uart_reset(DeviceState *dev)
463 CadenceUARTState *s = CADENCE_UART(dev);
465 s->r[R_CR] = 0x00000128;
468 s->r[R_RTRIG] = 0x00000020;
469 s->r[R_BRGR] = 0x0000028B;
470 s->r[R_BDIV] = 0x0000000F;
471 s->r[R_TTRIG] = 0x00000020;
476 uart_update_status(s);
479 static void cadence_uart_realize(DeviceState *dev, Error **errp)
481 CadenceUARTState *s = CADENCE_UART(dev);
483 s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL,
484 fifo_trigger_update, s);
486 qemu_chr_fe_set_handlers(&s->chr, uart_can_receive, uart_receive,
487 uart_event, s, NULL, true);
490 static void cadence_uart_init(Object *obj)
492 SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
493 CadenceUARTState *s = CADENCE_UART(obj);
495 memory_region_init_io(&s->iomem, obj, &uart_ops, s, "uart", 0x1000);
496 sysbus_init_mmio(sbd, &s->iomem);
497 sysbus_init_irq(sbd, &s->irq);
499 s->char_tx_time = (NANOSECONDS_PER_SECOND / 9600) * 10;
502 static int cadence_uart_post_load(void *opaque, int version_id)
504 CadenceUARTState *s = opaque;
506 /* Ensure these two aren't invalid numbers */
507 if (s->r[R_BRGR] < 1 || s->r[R_BRGR] & ~0xFFFF ||
508 s->r[R_BDIV] <= 3 || s->r[R_BDIV] & ~0xFF) {
509 /* Value is invalid, abort */
513 uart_parameters_setup(s);
514 uart_update_status(s);
518 static const VMStateDescription vmstate_cadence_uart = {
519 .name = "cadence_uart",
521 .minimum_version_id = 2,
522 .post_load = cadence_uart_post_load,
523 .fields = (VMStateField[]) {
524 VMSTATE_UINT32_ARRAY(r, CadenceUARTState, CADENCE_UART_R_MAX),
525 VMSTATE_UINT8_ARRAY(rx_fifo, CadenceUARTState,
526 CADENCE_UART_RX_FIFO_SIZE),
527 VMSTATE_UINT8_ARRAY(tx_fifo, CadenceUARTState,
528 CADENCE_UART_TX_FIFO_SIZE),
529 VMSTATE_UINT32(rx_count, CadenceUARTState),
530 VMSTATE_UINT32(tx_count, CadenceUARTState),
531 VMSTATE_UINT32(rx_wpos, CadenceUARTState),
532 VMSTATE_TIMER_PTR(fifo_trigger_handle, CadenceUARTState),
533 VMSTATE_END_OF_LIST()
537 static Property cadence_uart_properties[] = {
538 DEFINE_PROP_CHR("chardev", CadenceUARTState, chr),
539 DEFINE_PROP_END_OF_LIST(),
542 static void cadence_uart_class_init(ObjectClass *klass, void *data)
544 DeviceClass *dc = DEVICE_CLASS(klass);
546 dc->realize = cadence_uart_realize;
547 dc->vmsd = &vmstate_cadence_uart;
548 dc->reset = cadence_uart_reset;
549 dc->props = cadence_uart_properties;
552 static const TypeInfo cadence_uart_info = {
553 .name = TYPE_CADENCE_UART,
554 .parent = TYPE_SYS_BUS_DEVICE,
555 .instance_size = sizeof(CadenceUARTState),
556 .instance_init = cadence_uart_init,
557 .class_init = cadence_uart_class_init,
560 static void cadence_uart_register_types(void)
562 type_register_static(&cadence_uart_info);
565 type_init(cadence_uart_register_types)