]> Git Repo - qemu.git/blame - hw/char/cadence_uart.c
char/cadence_uart: Remove TX timer & add TX FIFO state
[qemu.git] / hw / char / cadence_uart.c
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1/*
2 * Device model for Cadence UART
3 *
4 * Copyright (c) 2010 Xilinx Inc.
5 * Copyright (c) 2012 Peter A.G. Crosthwaite ([email protected])
6 * Copyright (c) 2012 PetaLogix Pty Ltd.
7 * Written by Haibing Ma
8 * M.Habib
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, see <http://www.gnu.org/licenses/>.
17 */
18
83c9f4ca 19#include "hw/sysbus.h"
dccfcd0e 20#include "sysemu/char.h"
1de7afc9 21#include "qemu/timer.h"
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22
23#ifdef CADENCE_UART_ERR_DEBUG
24#define DB_PRINT(...) do { \
25 fprintf(stderr, ": %s: ", __func__); \
26 fprintf(stderr, ## __VA_ARGS__); \
27 } while (0);
28#else
29 #define DB_PRINT(...)
30#endif
31
32#define UART_SR_INTR_RTRIG 0x00000001
33#define UART_SR_INTR_REMPTY 0x00000002
34#define UART_SR_INTR_RFUL 0x00000004
35#define UART_SR_INTR_TEMPTY 0x00000008
36#define UART_SR_INTR_TFUL 0x00000010
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37/* somewhat awkwardly, TTRIG is misaligned between SR and ISR */
38#define UART_SR_TTRIG 0x00002000
39#define UART_INTR_TTRIG 0x00000400
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40/* bits fields in CSR that correlate to CISR. If any of these bits are set in
41 * SR, then the same bit in CISR is set high too */
42#define UART_SR_TO_CISR_MASK 0x0000001F
43
44#define UART_INTR_ROVR 0x00000020
45#define UART_INTR_FRAME 0x00000040
46#define UART_INTR_PARE 0x00000080
47#define UART_INTR_TIMEOUT 0x00000100
48#define UART_INTR_DMSI 0x00000200
11a239a5 49#define UART_INTR_TOVR 0x00001000
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50
51#define UART_SR_RACTIVE 0x00000400
52#define UART_SR_TACTIVE 0x00000800
53#define UART_SR_FDELT 0x00001000
54
55#define UART_CR_RXRST 0x00000001
56#define UART_CR_TXRST 0x00000002
57#define UART_CR_RX_EN 0x00000004
58#define UART_CR_RX_DIS 0x00000008
59#define UART_CR_TX_EN 0x00000010
60#define UART_CR_TX_DIS 0x00000020
61#define UART_CR_RST_TO 0x00000040
62#define UART_CR_STARTBRK 0x00000080
63#define UART_CR_STOPBRK 0x00000100
64
65#define UART_MR_CLKS 0x00000001
66#define UART_MR_CHRL 0x00000006
67#define UART_MR_CHRL_SH 1
68#define UART_MR_PAR 0x00000038
69#define UART_MR_PAR_SH 3
70#define UART_MR_NBSTOP 0x000000C0
71#define UART_MR_NBSTOP_SH 6
72#define UART_MR_CHMODE 0x00000300
73#define UART_MR_CHMODE_SH 8
74#define UART_MR_UCLKEN 0x00000400
75#define UART_MR_IRMODE 0x00000800
76
77#define UART_DATA_BITS_6 (0x3 << UART_MR_CHRL_SH)
78#define UART_DATA_BITS_7 (0x2 << UART_MR_CHRL_SH)
79#define UART_PARITY_ODD (0x1 << UART_MR_PAR_SH)
80#define UART_PARITY_EVEN (0x0 << UART_MR_PAR_SH)
81#define UART_STOP_BITS_1 (0x3 << UART_MR_NBSTOP_SH)
82#define UART_STOP_BITS_2 (0x2 << UART_MR_NBSTOP_SH)
83#define NORMAL_MODE (0x0 << UART_MR_CHMODE_SH)
84#define ECHO_MODE (0x1 << UART_MR_CHMODE_SH)
85#define LOCAL_LOOPBACK (0x2 << UART_MR_CHMODE_SH)
86#define REMOTE_LOOPBACK (0x3 << UART_MR_CHMODE_SH)
87
88#define RX_FIFO_SIZE 16
89#define TX_FIFO_SIZE 16
90#define UART_INPUT_CLK 50000000
91
92#define R_CR (0x00/4)
93#define R_MR (0x04/4)
94#define R_IER (0x08/4)
95#define R_IDR (0x0C/4)
96#define R_IMR (0x10/4)
97#define R_CISR (0x14/4)
98#define R_BRGR (0x18/4)
99#define R_RTOR (0x1C/4)
100#define R_RTRIG (0x20/4)
101#define R_MCR (0x24/4)
102#define R_MSR (0x28/4)
103#define R_SR (0x2C/4)
104#define R_TX_RX (0x30/4)
105#define R_BDIV (0x34/4)
106#define R_FDEL (0x38/4)
107#define R_PMIN (0x3C/4)
108#define R_PWID (0x40/4)
109#define R_TTRIG (0x44/4)
110
111#define R_MAX (R_TTRIG + 1)
112
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113#define TYPE_CADENCE_UART "cadence_uart"
114#define CADENCE_UART(obj) OBJECT_CHECK(UartState, (obj), TYPE_CADENCE_UART)
115
35548b06 116typedef struct {
059ca2bf 117 /*< private >*/
534f6ff9 118 SysBusDevice parent_obj;
059ca2bf 119 /*< public >*/
534f6ff9 120
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121 MemoryRegion iomem;
122 uint32_t r[R_MAX];
1e77c91e 123 uint8_t rx_fifo[RX_FIFO_SIZE];
2152e08a 124 uint8_t tx_fifo[TX_FIFO_SIZE];
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125 uint32_t rx_wpos;
126 uint32_t rx_count;
2152e08a 127 uint32_t tx_count;
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128 uint64_t char_tx_time;
129 CharDriverState *chr;
130 qemu_irq irq;
1246b259 131 QEMUTimer *fifo_trigger_handle;
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132} UartState;
133
134static void uart_update_status(UartState *s)
135{
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136 s->r[R_SR] = 0;
137
138 s->r[R_SR] |= s->rx_count == RX_FIFO_SIZE ? UART_SR_INTR_RFUL : 0;
139 s->r[R_SR] |= !s->rx_count ? UART_SR_INTR_REMPTY : 0;
140 s->r[R_SR] |= s->rx_count >= s->r[R_RTRIG] ? UART_SR_INTR_RTRIG : 0;
141
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142 s->r[R_SR] |= s->tx_count == TX_FIFO_SIZE ? UART_SR_INTR_TFUL : 0;
143 s->r[R_SR] |= !s->tx_count ? UART_SR_INTR_TEMPTY : 0;
144 s->r[R_SR] |= s->tx_count >= s->r[R_TTRIG] ? UART_SR_TTRIG : 0;
145
35548b06 146 s->r[R_CISR] |= s->r[R_SR] & UART_SR_TO_CISR_MASK;
2152e08a 147 s->r[R_CISR] |= s->r[R_SR] & UART_SR_TTRIG ? UART_INTR_TTRIG : 0;
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148 qemu_set_irq(s->irq, !!(s->r[R_IMR] & s->r[R_CISR]));
149}
150
151static void fifo_trigger_update(void *opaque)
152{
153 UartState *s = (UartState *)opaque;
154
155 s->r[R_CISR] |= UART_INTR_TIMEOUT;
156
157 uart_update_status(s);
158}
159
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160static void uart_rx_reset(UartState *s)
161{
162 s->rx_wpos = 0;
163 s->rx_count = 0;
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164 if (s->chr) {
165 qemu_chr_accept_input(s->chr);
166 }
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167}
168
169static void uart_tx_reset(UartState *s)
170{
2152e08a 171 s->tx_count = 0;
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172}
173
174static void uart_send_breaks(UartState *s)
175{
176 int break_enabled = 1;
177
178 qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_BREAK,
179 &break_enabled);
180}
181
182static void uart_parameters_setup(UartState *s)
183{
184 QEMUSerialSetParams ssp;
185 unsigned int baud_rate, packet_size;
186
187 baud_rate = (s->r[R_MR] & UART_MR_CLKS) ?
188 UART_INPUT_CLK / 8 : UART_INPUT_CLK;
189
190 ssp.speed = baud_rate / (s->r[R_BRGR] * (s->r[R_BDIV] + 1));
191 packet_size = 1;
192
193 switch (s->r[R_MR] & UART_MR_PAR) {
194 case UART_PARITY_EVEN:
195 ssp.parity = 'E';
196 packet_size++;
197 break;
198 case UART_PARITY_ODD:
199 ssp.parity = 'O';
200 packet_size++;
201 break;
202 default:
203 ssp.parity = 'N';
204 break;
205 }
206
207 switch (s->r[R_MR] & UART_MR_CHRL) {
208 case UART_DATA_BITS_6:
209 ssp.data_bits = 6;
210 break;
211 case UART_DATA_BITS_7:
212 ssp.data_bits = 7;
213 break;
214 default:
215 ssp.data_bits = 8;
216 break;
217 }
218
219 switch (s->r[R_MR] & UART_MR_NBSTOP) {
220 case UART_STOP_BITS_1:
221 ssp.stop_bits = 1;
222 break;
223 default:
224 ssp.stop_bits = 2;
225 break;
226 }
227
228 packet_size += ssp.data_bits + ssp.stop_bits;
229 s->char_tx_time = (get_ticks_per_sec() / ssp.speed) * packet_size;
230 qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
231}
232
233static int uart_can_receive(void *opaque)
234{
235 UartState *s = (UartState *)opaque;
236
237 return RX_FIFO_SIZE - s->rx_count;
238}
239
240static void uart_ctrl_update(UartState *s)
241{
242 if (s->r[R_CR] & UART_CR_TXRST) {
243 uart_tx_reset(s);
244 }
245
246 if (s->r[R_CR] & UART_CR_RXRST) {
247 uart_rx_reset(s);
248 }
249
250 s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST);
251
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252 if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) {
253 uart_send_breaks(s);
254 }
255}
256
257static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size)
258{
259 UartState *s = (UartState *)opaque;
bc72ad67 260 uint64_t new_rx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
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261 int i;
262
263 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) {
264 return;
265 }
266
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267 if (s->rx_count == RX_FIFO_SIZE) {
268 s->r[R_CISR] |= UART_INTR_ROVR;
269 } else {
270 for (i = 0; i < size; i++) {
1e77c91e 271 s->rx_fifo[s->rx_wpos] = buf[i];
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272 s->rx_wpos = (s->rx_wpos + 1) % RX_FIFO_SIZE;
273 s->rx_count++;
35548b06 274 }
bc72ad67 275 timer_mod(s->fifo_trigger_handle, new_rx_time +
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276 (s->char_tx_time * 4));
277 }
278 uart_update_status(s);
279}
280
281static void uart_write_tx_fifo(UartState *s, const uint8_t *buf, int size)
282{
283 if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) {
284 return;
285 }
286
b52df465 287 qemu_chr_fe_write_all(s->chr, buf, size);
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288}
289
290static void uart_receive(void *opaque, const uint8_t *buf, int size)
291{
292 UartState *s = (UartState *)opaque;
293 uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
294
295 if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
296 uart_write_rx_fifo(opaque, buf, size);
297 }
298 if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) {
299 uart_write_tx_fifo(s, buf, size);
300 }
301}
302
303static void uart_event(void *opaque, int event)
304{
305 UartState *s = (UartState *)opaque;
306 uint8_t buf = '\0';
307
308 if (event == CHR_EVENT_BREAK) {
309 uart_write_rx_fifo(opaque, &buf, 1);
310 }
311
312 uart_update_status(s);
313}
314
315static void uart_read_rx_fifo(UartState *s, uint32_t *c)
316{
317 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) {
318 return;
319 }
320
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321 if (s->rx_count) {
322 uint32_t rx_rpos =
323 (RX_FIFO_SIZE + s->rx_wpos - s->rx_count) % RX_FIFO_SIZE;
1e77c91e 324 *c = s->rx_fifo[rx_rpos];
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325 s->rx_count--;
326
9893c80d 327 qemu_chr_accept_input(s->chr);
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328 } else {
329 *c = 0;
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330 }
331
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332 uart_update_status(s);
333}
334
a8170e5e 335static void uart_write(void *opaque, hwaddr offset,
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336 uint64_t value, unsigned size)
337{
338 UartState *s = (UartState *)opaque;
339
2ddef11b 340 DB_PRINT(" offset:%x data:%08x\n", (unsigned)offset, (unsigned)value);
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341 offset >>= 2;
342 switch (offset) {
343 case R_IER: /* ier (wts imr) */
344 s->r[R_IMR] |= value;
345 break;
346 case R_IDR: /* idr (wtc imr) */
347 s->r[R_IMR] &= ~value;
348 break;
349 case R_IMR: /* imr (read only) */
350 break;
351 case R_CISR: /* cisr (wtc) */
352 s->r[R_CISR] &= ~value;
353 break;
354 case R_TX_RX: /* UARTDR */
355 switch (s->r[R_MR] & UART_MR_CHMODE) {
356 case NORMAL_MODE:
357 uart_write_tx_fifo(s, (uint8_t *) &value, 1);
358 break;
359 case LOCAL_LOOPBACK:
360 uart_write_rx_fifo(opaque, (uint8_t *) &value, 1);
361 break;
362 }
363 break;
364 default:
365 s->r[offset] = value;
366 }
367
368 switch (offset) {
369 case R_CR:
370 uart_ctrl_update(s);
371 break;
372 case R_MR:
373 uart_parameters_setup(s);
374 break;
375 }
589bfb68 376 uart_update_status(s);
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377}
378
a8170e5e 379static uint64_t uart_read(void *opaque, hwaddr offset,
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380 unsigned size)
381{
382 UartState *s = (UartState *)opaque;
383 uint32_t c = 0;
384
385 offset >>= 2;
5d40097f 386 if (offset >= R_MAX) {
2ddef11b 387 c = 0;
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388 } else if (offset == R_TX_RX) {
389 uart_read_rx_fifo(s, &c);
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390 } else {
391 c = s->r[offset];
35548b06 392 }
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393
394 DB_PRINT(" offset:%x data:%08x\n", (unsigned)(offset << 2), (unsigned)c);
395 return c;
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396}
397
398static const MemoryRegionOps uart_ops = {
399 .read = uart_read,
400 .write = uart_write,
401 .endianness = DEVICE_NATIVE_ENDIAN,
402};
403
823dd487 404static void cadence_uart_reset(DeviceState *dev)
35548b06 405{
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406 UartState *s = CADENCE_UART(dev);
407
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408 s->r[R_CR] = 0x00000128;
409 s->r[R_IMR] = 0;
410 s->r[R_CISR] = 0;
411 s->r[R_RTRIG] = 0x00000020;
412 s->r[R_BRGR] = 0x0000000F;
413 s->r[R_TTRIG] = 0x00000020;
414
415 uart_rx_reset(s);
416 uart_tx_reset(s);
417
418 s->rx_count = 0;
419 s->rx_wpos = 0;
676f4c09 420 uart_update_status(s);
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421}
422
423static int cadence_uart_init(SysBusDevice *dev)
424{
534f6ff9 425 UartState *s = CADENCE_UART(dev);
35548b06 426
300b1fc6 427 memory_region_init_io(&s->iomem, OBJECT(s), &uart_ops, s, "uart", 0x1000);
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428 sysbus_init_mmio(dev, &s->iomem);
429 sysbus_init_irq(dev, &s->irq);
430
bc72ad67 431 s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL,
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432 (QEMUTimerCB *)fifo_trigger_update, s);
433
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434 s->char_tx_time = (get_ticks_per_sec() / 9600) * 10;
435
436 s->chr = qemu_char_get_next_serial();
437
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438 if (s->chr) {
439 qemu_chr_add_handlers(s->chr, uart_can_receive, uart_receive,
440 uart_event, s);
441 }
442
443 return 0;
444}
445
446static int cadence_uart_post_load(void *opaque, int version_id)
447{
448 UartState *s = opaque;
449
450 uart_parameters_setup(s);
451 uart_update_status(s);
452 return 0;
453}
454
455static const VMStateDescription vmstate_cadence_uart = {
456 .name = "cadence_uart",
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457 .version_id = 2,
458 .minimum_version_id = 2,
459 .minimum_version_id_old = 2,
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460 .post_load = cadence_uart_post_load,
461 .fields = (VMStateField[]) {
462 VMSTATE_UINT32_ARRAY(r, UartState, R_MAX),
1e77c91e 463 VMSTATE_UINT8_ARRAY(rx_fifo, UartState, RX_FIFO_SIZE),
2152e08a 464 VMSTATE_UINT8_ARRAY(tx_fifo, UartState, RX_FIFO_SIZE),
35548b06 465 VMSTATE_UINT32(rx_count, UartState),
2152e08a 466 VMSTATE_UINT32(tx_count, UartState),
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467 VMSTATE_UINT32(rx_wpos, UartState),
468 VMSTATE_TIMER(fifo_trigger_handle, UartState),
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469 VMSTATE_END_OF_LIST()
470 }
471};
472
473static void cadence_uart_class_init(ObjectClass *klass, void *data)
474{
475 DeviceClass *dc = DEVICE_CLASS(klass);
476 SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
477
478 sdc->init = cadence_uart_init;
479 dc->vmsd = &vmstate_cadence_uart;
823dd487 480 dc->reset = cadence_uart_reset;
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481}
482
8c43a6f0 483static const TypeInfo cadence_uart_info = {
534f6ff9 484 .name = TYPE_CADENCE_UART,
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485 .parent = TYPE_SYS_BUS_DEVICE,
486 .instance_size = sizeof(UartState),
487 .class_init = cadence_uart_class_init,
488};
489
490static void cadence_uart_register_types(void)
491{
492 type_register_static(&cadence_uart_info);
493}
494
495type_init(cadence_uart_register_types)
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