]> Git Repo - qemu.git/blame - hw/char/cadence_uart.c
char/cadence_uart: Fix can_receive logic
[qemu.git] / hw / char / cadence_uart.c
CommitLineData
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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;
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236 int ret = MAX(RX_FIFO_SIZE, TX_FIFO_SIZE);
237 uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
35548b06 238
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239 if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
240 ret = MIN(ret, RX_FIFO_SIZE - s->rx_count);
241 }
242 if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) {
243 ret = MIN(ret, TX_FIFO_SIZE - s->tx_count);
244 }
245 return ret;
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246}
247
248static void uart_ctrl_update(UartState *s)
249{
250 if (s->r[R_CR] & UART_CR_TXRST) {
251 uart_tx_reset(s);
252 }
253
254 if (s->r[R_CR] & UART_CR_RXRST) {
255 uart_rx_reset(s);
256 }
257
258 s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST);
259
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260 if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) {
261 uart_send_breaks(s);
262 }
263}
264
265static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size)
266{
267 UartState *s = (UartState *)opaque;
bc72ad67 268 uint64_t new_rx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
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269 int i;
270
271 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) {
272 return;
273 }
274
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275 if (s->rx_count == RX_FIFO_SIZE) {
276 s->r[R_CISR] |= UART_INTR_ROVR;
277 } else {
278 for (i = 0; i < size; i++) {
1e77c91e 279 s->rx_fifo[s->rx_wpos] = buf[i];
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280 s->rx_wpos = (s->rx_wpos + 1) % RX_FIFO_SIZE;
281 s->rx_count++;
35548b06 282 }
bc72ad67 283 timer_mod(s->fifo_trigger_handle, new_rx_time +
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284 (s->char_tx_time * 4));
285 }
286 uart_update_status(s);
287}
288
289static void uart_write_tx_fifo(UartState *s, const uint8_t *buf, int size)
290{
291 if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) {
292 return;
293 }
294
b52df465 295 qemu_chr_fe_write_all(s->chr, buf, size);
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296}
297
298static void uart_receive(void *opaque, const uint8_t *buf, int size)
299{
300 UartState *s = (UartState *)opaque;
301 uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
302
303 if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
304 uart_write_rx_fifo(opaque, buf, size);
305 }
306 if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) {
307 uart_write_tx_fifo(s, buf, size);
308 }
309}
310
311static void uart_event(void *opaque, int event)
312{
313 UartState *s = (UartState *)opaque;
314 uint8_t buf = '\0';
315
316 if (event == CHR_EVENT_BREAK) {
317 uart_write_rx_fifo(opaque, &buf, 1);
318 }
319
320 uart_update_status(s);
321}
322
323static void uart_read_rx_fifo(UartState *s, uint32_t *c)
324{
325 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) {
326 return;
327 }
328
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329 if (s->rx_count) {
330 uint32_t rx_rpos =
331 (RX_FIFO_SIZE + s->rx_wpos - s->rx_count) % RX_FIFO_SIZE;
1e77c91e 332 *c = s->rx_fifo[rx_rpos];
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333 s->rx_count--;
334
9893c80d 335 qemu_chr_accept_input(s->chr);
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336 } else {
337 *c = 0;
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338 }
339
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340 uart_update_status(s);
341}
342
a8170e5e 343static void uart_write(void *opaque, hwaddr offset,
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344 uint64_t value, unsigned size)
345{
346 UartState *s = (UartState *)opaque;
347
2ddef11b 348 DB_PRINT(" offset:%x data:%08x\n", (unsigned)offset, (unsigned)value);
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349 offset >>= 2;
350 switch (offset) {
351 case R_IER: /* ier (wts imr) */
352 s->r[R_IMR] |= value;
353 break;
354 case R_IDR: /* idr (wtc imr) */
355 s->r[R_IMR] &= ~value;
356 break;
357 case R_IMR: /* imr (read only) */
358 break;
359 case R_CISR: /* cisr (wtc) */
360 s->r[R_CISR] &= ~value;
361 break;
362 case R_TX_RX: /* UARTDR */
363 switch (s->r[R_MR] & UART_MR_CHMODE) {
364 case NORMAL_MODE:
365 uart_write_tx_fifo(s, (uint8_t *) &value, 1);
366 break;
367 case LOCAL_LOOPBACK:
368 uart_write_rx_fifo(opaque, (uint8_t *) &value, 1);
369 break;
370 }
371 break;
372 default:
373 s->r[offset] = value;
374 }
375
376 switch (offset) {
377 case R_CR:
378 uart_ctrl_update(s);
379 break;
380 case R_MR:
381 uart_parameters_setup(s);
382 break;
383 }
589bfb68 384 uart_update_status(s);
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385}
386
a8170e5e 387static uint64_t uart_read(void *opaque, hwaddr offset,
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388 unsigned size)
389{
390 UartState *s = (UartState *)opaque;
391 uint32_t c = 0;
392
393 offset >>= 2;
5d40097f 394 if (offset >= R_MAX) {
2ddef11b 395 c = 0;
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396 } else if (offset == R_TX_RX) {
397 uart_read_rx_fifo(s, &c);
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398 } else {
399 c = s->r[offset];
35548b06 400 }
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401
402 DB_PRINT(" offset:%x data:%08x\n", (unsigned)(offset << 2), (unsigned)c);
403 return c;
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404}
405
406static const MemoryRegionOps uart_ops = {
407 .read = uart_read,
408 .write = uart_write,
409 .endianness = DEVICE_NATIVE_ENDIAN,
410};
411
823dd487 412static void cadence_uart_reset(DeviceState *dev)
35548b06 413{
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414 UartState *s = CADENCE_UART(dev);
415
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416 s->r[R_CR] = 0x00000128;
417 s->r[R_IMR] = 0;
418 s->r[R_CISR] = 0;
419 s->r[R_RTRIG] = 0x00000020;
420 s->r[R_BRGR] = 0x0000000F;
421 s->r[R_TTRIG] = 0x00000020;
422
423 uart_rx_reset(s);
424 uart_tx_reset(s);
425
426 s->rx_count = 0;
427 s->rx_wpos = 0;
676f4c09 428 uart_update_status(s);
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429}
430
431static int cadence_uart_init(SysBusDevice *dev)
432{
534f6ff9 433 UartState *s = CADENCE_UART(dev);
35548b06 434
300b1fc6 435 memory_region_init_io(&s->iomem, OBJECT(s), &uart_ops, s, "uart", 0x1000);
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436 sysbus_init_mmio(dev, &s->iomem);
437 sysbus_init_irq(dev, &s->irq);
438
bc72ad67 439 s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL,
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440 (QEMUTimerCB *)fifo_trigger_update, s);
441
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442 s->char_tx_time = (get_ticks_per_sec() / 9600) * 10;
443
444 s->chr = qemu_char_get_next_serial();
445
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446 if (s->chr) {
447 qemu_chr_add_handlers(s->chr, uart_can_receive, uart_receive,
448 uart_event, s);
449 }
450
451 return 0;
452}
453
454static int cadence_uart_post_load(void *opaque, int version_id)
455{
456 UartState *s = opaque;
457
458 uart_parameters_setup(s);
459 uart_update_status(s);
460 return 0;
461}
462
463static const VMStateDescription vmstate_cadence_uart = {
464 .name = "cadence_uart",
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465 .version_id = 2,
466 .minimum_version_id = 2,
467 .minimum_version_id_old = 2,
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468 .post_load = cadence_uart_post_load,
469 .fields = (VMStateField[]) {
470 VMSTATE_UINT32_ARRAY(r, UartState, R_MAX),
1e77c91e 471 VMSTATE_UINT8_ARRAY(rx_fifo, UartState, RX_FIFO_SIZE),
2152e08a 472 VMSTATE_UINT8_ARRAY(tx_fifo, UartState, RX_FIFO_SIZE),
35548b06 473 VMSTATE_UINT32(rx_count, UartState),
2152e08a 474 VMSTATE_UINT32(tx_count, UartState),
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475 VMSTATE_UINT32(rx_wpos, UartState),
476 VMSTATE_TIMER(fifo_trigger_handle, UartState),
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477 VMSTATE_END_OF_LIST()
478 }
479};
480
481static void cadence_uart_class_init(ObjectClass *klass, void *data)
482{
483 DeviceClass *dc = DEVICE_CLASS(klass);
484 SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
485
486 sdc->init = cadence_uart_init;
487 dc->vmsd = &vmstate_cadence_uart;
823dd487 488 dc->reset = cadence_uart_reset;
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489}
490
8c43a6f0 491static const TypeInfo cadence_uart_info = {
534f6ff9 492 .name = TYPE_CADENCE_UART,
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493 .parent = TYPE_SYS_BUS_DEVICE,
494 .instance_size = sizeof(UartState),
495 .class_init = cadence_uart_class_init,
496};
497
498static void cadence_uart_register_types(void)
499{
500 type_register_static(&cadence_uart_info);
501}
502
503type_init(cadence_uart_register_types)
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