aspeed/i2c: Enable SLAVE_ADDR_RX_MATCH always
[qemu.git] / hw / char / ibex_uart.c
blobe58181fcf429323d6b2b444864cb59ca9c9bc1e0
1 /*
2 * QEMU lowRISC Ibex UART device
4 * Copyright (c) 2020 Western Digital
6 * For details check the documentation here:
7 * https://docs.opentitan.org/hw/ip/uart/doc/
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * THE SOFTWARE.
28 #include "qemu/osdep.h"
29 #include "hw/char/ibex_uart.h"
30 #include "hw/irq.h"
31 #include "hw/qdev-clock.h"
32 #include "hw/qdev-properties.h"
33 #include "hw/qdev-properties-system.h"
34 #include "migration/vmstate.h"
35 #include "qemu/log.h"
36 #include "qemu/module.h"
38 REG32(INTR_STATE, 0x00)
39 FIELD(INTR_STATE, TX_WATERMARK, 0, 1)
40 FIELD(INTR_STATE, RX_WATERMARK, 1, 1)
41 FIELD(INTR_STATE, TX_EMPTY, 2, 1)
42 FIELD(INTR_STATE, RX_OVERFLOW, 3, 1)
43 REG32(INTR_ENABLE, 0x04)
44 REG32(INTR_TEST, 0x08)
45 REG32(ALERT_TEST, 0x0C)
46 REG32(CTRL, 0x10)
47 FIELD(CTRL, TX_ENABLE, 0, 1)
48 FIELD(CTRL, RX_ENABLE, 1, 1)
49 FIELD(CTRL, NF, 2, 1)
50 FIELD(CTRL, SLPBK, 4, 1)
51 FIELD(CTRL, LLPBK, 5, 1)
52 FIELD(CTRL, PARITY_EN, 6, 1)
53 FIELD(CTRL, PARITY_ODD, 7, 1)
54 FIELD(CTRL, RXBLVL, 8, 2)
55 FIELD(CTRL, NCO, 16, 16)
56 REG32(STATUS, 0x14)
57 FIELD(STATUS, TXFULL, 0, 1)
58 FIELD(STATUS, RXFULL, 1, 1)
59 FIELD(STATUS, TXEMPTY, 2, 1)
60 FIELD(STATUS, RXIDLE, 4, 1)
61 FIELD(STATUS, RXEMPTY, 5, 1)
62 REG32(RDATA, 0x18)
63 REG32(WDATA, 0x1C)
64 REG32(FIFO_CTRL, 0x20)
65 FIELD(FIFO_CTRL, RXRST, 0, 1)
66 FIELD(FIFO_CTRL, TXRST, 1, 1)
67 FIELD(FIFO_CTRL, RXILVL, 2, 3)
68 FIELD(FIFO_CTRL, TXILVL, 5, 2)
69 REG32(FIFO_STATUS, 0x24)
70 FIELD(FIFO_STATUS, TXLVL, 0, 5)
71 FIELD(FIFO_STATUS, RXLVL, 16, 5)
72 REG32(OVRD, 0x28)
73 REG32(VAL, 0x2C)
74 REG32(TIMEOUT_CTRL, 0x30)
76 static void ibex_uart_update_irqs(IbexUartState *s)
78 if (s->uart_intr_state & s->uart_intr_enable & R_INTR_STATE_TX_WATERMARK_MASK) {
79 qemu_set_irq(s->tx_watermark, 1);
80 } else {
81 qemu_set_irq(s->tx_watermark, 0);
84 if (s->uart_intr_state & s->uart_intr_enable & R_INTR_STATE_RX_WATERMARK_MASK) {
85 qemu_set_irq(s->rx_watermark, 1);
86 } else {
87 qemu_set_irq(s->rx_watermark, 0);
90 if (s->uart_intr_state & s->uart_intr_enable & R_INTR_STATE_TX_EMPTY_MASK) {
91 qemu_set_irq(s->tx_empty, 1);
92 } else {
93 qemu_set_irq(s->tx_empty, 0);
96 if (s->uart_intr_state & s->uart_intr_enable & R_INTR_STATE_RX_OVERFLOW_MASK) {
97 qemu_set_irq(s->rx_overflow, 1);
98 } else {
99 qemu_set_irq(s->rx_overflow, 0);
103 static int ibex_uart_can_receive(void *opaque)
105 IbexUartState *s = opaque;
107 if ((s->uart_ctrl & R_CTRL_RX_ENABLE_MASK)
108 && !(s->uart_status & R_STATUS_RXFULL_MASK)) {
109 return 1;
112 return 0;
115 static void ibex_uart_receive(void *opaque, const uint8_t *buf, int size)
117 IbexUartState *s = opaque;
118 uint8_t rx_fifo_level = (s->uart_fifo_ctrl & R_FIFO_CTRL_RXILVL_MASK)
119 >> R_FIFO_CTRL_RXILVL_SHIFT;
121 s->uart_rdata = *buf;
123 s->uart_status &= ~R_STATUS_RXIDLE_MASK;
124 s->uart_status &= ~R_STATUS_RXEMPTY_MASK;
125 /* The RXFULL is set after receiving a single byte
126 * as the FIFO buffers are not yet implemented.
128 s->uart_status |= R_STATUS_RXFULL_MASK;
129 s->rx_level += 1;
131 if (size > rx_fifo_level) {
132 s->uart_intr_state |= R_INTR_STATE_RX_WATERMARK_MASK;
135 ibex_uart_update_irqs(s);
138 static gboolean ibex_uart_xmit(void *do_not_use, GIOCondition cond,
139 void *opaque)
141 IbexUartState *s = opaque;
142 uint8_t tx_fifo_level = (s->uart_fifo_ctrl & R_FIFO_CTRL_TXILVL_MASK)
143 >> R_FIFO_CTRL_TXILVL_SHIFT;
144 int ret;
146 /* instant drain the fifo when there's no back-end */
147 if (!qemu_chr_fe_backend_connected(&s->chr)) {
148 s->tx_level = 0;
149 return FALSE;
152 if (!s->tx_level) {
153 s->uart_status &= ~R_STATUS_TXFULL_MASK;
154 s->uart_status |= R_STATUS_TXEMPTY_MASK;
155 s->uart_intr_state |= R_INTR_STATE_TX_EMPTY_MASK;
156 s->uart_intr_state &= ~R_INTR_STATE_TX_WATERMARK_MASK;
157 ibex_uart_update_irqs(s);
158 return FALSE;
161 ret = qemu_chr_fe_write(&s->chr, s->tx_fifo, s->tx_level);
163 if (ret >= 0) {
164 s->tx_level -= ret;
165 memmove(s->tx_fifo, s->tx_fifo + ret, s->tx_level);
168 if (s->tx_level) {
169 guint r = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP,
170 ibex_uart_xmit, s);
171 if (!r) {
172 s->tx_level = 0;
173 return FALSE;
177 /* Clear the TX Full bit */
178 if (s->tx_level != IBEX_UART_TX_FIFO_SIZE) {
179 s->uart_status &= ~R_STATUS_TXFULL_MASK;
182 /* Disable the TX_WATERMARK IRQ */
183 if (s->tx_level < tx_fifo_level) {
184 s->uart_intr_state &= ~R_INTR_STATE_TX_WATERMARK_MASK;
187 /* Set TX empty */
188 if (s->tx_level == 0) {
189 s->uart_status |= R_STATUS_TXEMPTY_MASK;
190 s->uart_intr_state |= R_INTR_STATE_TX_EMPTY_MASK;
193 ibex_uart_update_irqs(s);
194 return FALSE;
197 static void uart_write_tx_fifo(IbexUartState *s, const uint8_t *buf,
198 int size)
200 uint64_t current_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
201 uint8_t tx_fifo_level = (s->uart_fifo_ctrl & R_FIFO_CTRL_TXILVL_MASK)
202 >> R_FIFO_CTRL_TXILVL_SHIFT;
204 if (size > IBEX_UART_TX_FIFO_SIZE - s->tx_level) {
205 size = IBEX_UART_TX_FIFO_SIZE - s->tx_level;
206 qemu_log_mask(LOG_GUEST_ERROR, "ibex_uart: TX FIFO overflow");
209 memcpy(s->tx_fifo + s->tx_level, buf, size);
210 s->tx_level += size;
212 if (s->tx_level > 0) {
213 s->uart_status &= ~R_STATUS_TXEMPTY_MASK;
216 if (s->tx_level >= tx_fifo_level) {
217 s->uart_intr_state |= R_INTR_STATE_TX_WATERMARK_MASK;
218 ibex_uart_update_irqs(s);
221 if (s->tx_level == IBEX_UART_TX_FIFO_SIZE) {
222 s->uart_status |= R_STATUS_TXFULL_MASK;
225 timer_mod(s->fifo_trigger_handle, current_time +
226 (s->char_tx_time * 4));
229 static void ibex_uart_reset(DeviceState *dev)
231 IbexUartState *s = IBEX_UART(dev);
233 s->uart_intr_state = 0x00000000;
234 s->uart_intr_state = 0x00000000;
235 s->uart_intr_enable = 0x00000000;
236 s->uart_ctrl = 0x00000000;
237 s->uart_status = 0x0000003c;
238 s->uart_rdata = 0x00000000;
239 s->uart_fifo_ctrl = 0x00000000;
240 s->uart_fifo_status = 0x00000000;
241 s->uart_ovrd = 0x00000000;
242 s->uart_val = 0x00000000;
243 s->uart_timeout_ctrl = 0x00000000;
245 s->tx_level = 0;
246 s->rx_level = 0;
248 s->char_tx_time = (NANOSECONDS_PER_SECOND / 230400) * 10;
250 ibex_uart_update_irqs(s);
253 static uint64_t ibex_uart_get_baud(IbexUartState *s)
255 uint64_t baud;
257 baud = ((s->uart_ctrl & R_CTRL_NCO_MASK) >> 16);
258 baud *= clock_get_hz(s->f_clk);
259 baud >>= 20;
261 return baud;
264 static uint64_t ibex_uart_read(void *opaque, hwaddr addr,
265 unsigned int size)
267 IbexUartState *s = opaque;
268 uint64_t retvalue = 0;
270 switch (addr >> 2) {
271 case R_INTR_STATE:
272 retvalue = s->uart_intr_state;
273 break;
274 case R_INTR_ENABLE:
275 retvalue = s->uart_intr_enable;
276 break;
277 case R_INTR_TEST:
278 qemu_log_mask(LOG_GUEST_ERROR,
279 "%s: wdata is write only\n", __func__);
280 break;
282 case R_CTRL:
283 retvalue = s->uart_ctrl;
284 break;
285 case R_STATUS:
286 retvalue = s->uart_status;
287 break;
289 case R_RDATA:
290 retvalue = s->uart_rdata;
291 if ((s->uart_ctrl & R_CTRL_RX_ENABLE_MASK) && (s->rx_level > 0)) {
292 qemu_chr_fe_accept_input(&s->chr);
294 s->rx_level -= 1;
295 s->uart_status &= ~R_STATUS_RXFULL_MASK;
296 if (s->rx_level == 0) {
297 s->uart_status |= R_STATUS_RXIDLE_MASK;
298 s->uart_status |= R_STATUS_RXEMPTY_MASK;
301 break;
302 case R_WDATA:
303 qemu_log_mask(LOG_GUEST_ERROR,
304 "%s: wdata is write only\n", __func__);
305 break;
307 case R_FIFO_CTRL:
308 retvalue = s->uart_fifo_ctrl;
309 break;
310 case R_FIFO_STATUS:
311 retvalue = s->uart_fifo_status;
313 retvalue |= (s->rx_level & 0x1F) << R_FIFO_STATUS_RXLVL_SHIFT;
314 retvalue |= (s->tx_level & 0x1F) << R_FIFO_STATUS_TXLVL_SHIFT;
316 qemu_log_mask(LOG_UNIMP,
317 "%s: RX fifos are not supported\n", __func__);
318 break;
320 case R_OVRD:
321 retvalue = s->uart_ovrd;
322 qemu_log_mask(LOG_UNIMP,
323 "%s: ovrd is not supported\n", __func__);
324 break;
325 case R_VAL:
326 retvalue = s->uart_val;
327 qemu_log_mask(LOG_UNIMP,
328 "%s: val is not supported\n", __func__);
329 break;
330 case R_TIMEOUT_CTRL:
331 retvalue = s->uart_timeout_ctrl;
332 qemu_log_mask(LOG_UNIMP,
333 "%s: timeout_ctrl is not supported\n", __func__);
334 break;
335 default:
336 qemu_log_mask(LOG_GUEST_ERROR,
337 "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
338 return 0;
341 return retvalue;
344 static void ibex_uart_write(void *opaque, hwaddr addr,
345 uint64_t val64, unsigned int size)
347 IbexUartState *s = opaque;
348 uint32_t value = val64;
350 switch (addr >> 2) {
351 case R_INTR_STATE:
352 /* Write 1 clear */
353 s->uart_intr_state &= ~value;
354 ibex_uart_update_irqs(s);
355 break;
356 case R_INTR_ENABLE:
357 s->uart_intr_enable = value;
358 ibex_uart_update_irqs(s);
359 break;
360 case R_INTR_TEST:
361 s->uart_intr_state |= value;
362 ibex_uart_update_irqs(s);
363 break;
365 case R_CTRL:
366 s->uart_ctrl = value;
368 if (value & R_CTRL_NF_MASK) {
369 qemu_log_mask(LOG_UNIMP,
370 "%s: UART_CTRL_NF is not supported\n", __func__);
372 if (value & R_CTRL_SLPBK_MASK) {
373 qemu_log_mask(LOG_UNIMP,
374 "%s: UART_CTRL_SLPBK is not supported\n", __func__);
376 if (value & R_CTRL_LLPBK_MASK) {
377 qemu_log_mask(LOG_UNIMP,
378 "%s: UART_CTRL_LLPBK is not supported\n", __func__);
380 if (value & R_CTRL_PARITY_EN_MASK) {
381 qemu_log_mask(LOG_UNIMP,
382 "%s: UART_CTRL_PARITY_EN is not supported\n",
383 __func__);
385 if (value & R_CTRL_PARITY_ODD_MASK) {
386 qemu_log_mask(LOG_UNIMP,
387 "%s: UART_CTRL_PARITY_ODD is not supported\n",
388 __func__);
390 if (value & R_CTRL_RXBLVL_MASK) {
391 qemu_log_mask(LOG_UNIMP,
392 "%s: UART_CTRL_RXBLVL is not supported\n", __func__);
394 if (value & R_CTRL_NCO_MASK) {
395 uint64_t baud = ibex_uart_get_baud(s);
397 s->char_tx_time = (NANOSECONDS_PER_SECOND / baud) * 10;
399 break;
400 case R_STATUS:
401 qemu_log_mask(LOG_GUEST_ERROR,
402 "%s: status is read only\n", __func__);
403 break;
405 case R_RDATA:
406 qemu_log_mask(LOG_GUEST_ERROR,
407 "%s: rdata is read only\n", __func__);
408 break;
409 case R_WDATA:
410 uart_write_tx_fifo(s, (uint8_t *) &value, 1);
411 break;
413 case R_FIFO_CTRL:
414 s->uart_fifo_ctrl = value;
416 if (value & R_FIFO_CTRL_RXRST_MASK) {
417 s->rx_level = 0;
418 qemu_log_mask(LOG_UNIMP,
419 "%s: RX fifos are not supported\n", __func__);
421 if (value & R_FIFO_CTRL_TXRST_MASK) {
422 s->tx_level = 0;
424 break;
425 case R_FIFO_STATUS:
426 qemu_log_mask(LOG_GUEST_ERROR,
427 "%s: fifo_status is read only\n", __func__);
428 break;
430 case R_OVRD:
431 s->uart_ovrd = value;
432 qemu_log_mask(LOG_UNIMP,
433 "%s: ovrd is not supported\n", __func__);
434 break;
435 case R_VAL:
436 qemu_log_mask(LOG_GUEST_ERROR,
437 "%s: val is read only\n", __func__);
438 break;
439 case R_TIMEOUT_CTRL:
440 s->uart_timeout_ctrl = value;
441 qemu_log_mask(LOG_UNIMP,
442 "%s: timeout_ctrl is not supported\n", __func__);
443 break;
444 default:
445 qemu_log_mask(LOG_GUEST_ERROR,
446 "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
450 static void ibex_uart_clk_update(void *opaque, ClockEvent event)
452 IbexUartState *s = opaque;
454 /* recompute uart's speed on clock change */
455 uint64_t baud = ibex_uart_get_baud(s);
457 s->char_tx_time = (NANOSECONDS_PER_SECOND / baud) * 10;
460 static void fifo_trigger_update(void *opaque)
462 IbexUartState *s = opaque;
464 if (s->uart_ctrl & R_CTRL_TX_ENABLE_MASK) {
465 ibex_uart_xmit(NULL, G_IO_OUT, s);
469 static const MemoryRegionOps ibex_uart_ops = {
470 .read = ibex_uart_read,
471 .write = ibex_uart_write,
472 .endianness = DEVICE_NATIVE_ENDIAN,
473 .impl.min_access_size = 4,
474 .impl.max_access_size = 4,
477 static int ibex_uart_post_load(void *opaque, int version_id)
479 IbexUartState *s = opaque;
481 ibex_uart_update_irqs(s);
482 return 0;
485 static const VMStateDescription vmstate_ibex_uart = {
486 .name = TYPE_IBEX_UART,
487 .version_id = 1,
488 .minimum_version_id = 1,
489 .post_load = ibex_uart_post_load,
490 .fields = (VMStateField[]) {
491 VMSTATE_UINT8_ARRAY(tx_fifo, IbexUartState,
492 IBEX_UART_TX_FIFO_SIZE),
493 VMSTATE_UINT32(tx_level, IbexUartState),
494 VMSTATE_UINT64(char_tx_time, IbexUartState),
495 VMSTATE_TIMER_PTR(fifo_trigger_handle, IbexUartState),
496 VMSTATE_UINT32(uart_intr_state, IbexUartState),
497 VMSTATE_UINT32(uart_intr_enable, IbexUartState),
498 VMSTATE_UINT32(uart_ctrl, IbexUartState),
499 VMSTATE_UINT32(uart_status, IbexUartState),
500 VMSTATE_UINT32(uart_rdata, IbexUartState),
501 VMSTATE_UINT32(uart_fifo_ctrl, IbexUartState),
502 VMSTATE_UINT32(uart_fifo_status, IbexUartState),
503 VMSTATE_UINT32(uart_ovrd, IbexUartState),
504 VMSTATE_UINT32(uart_val, IbexUartState),
505 VMSTATE_UINT32(uart_timeout_ctrl, IbexUartState),
506 VMSTATE_END_OF_LIST()
510 static Property ibex_uart_properties[] = {
511 DEFINE_PROP_CHR("chardev", IbexUartState, chr),
512 DEFINE_PROP_END_OF_LIST(),
515 static void ibex_uart_init(Object *obj)
517 IbexUartState *s = IBEX_UART(obj);
519 s->f_clk = qdev_init_clock_in(DEVICE(obj), "f_clock",
520 ibex_uart_clk_update, s, ClockUpdate);
521 clock_set_hz(s->f_clk, IBEX_UART_CLOCK);
523 sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->tx_watermark);
524 sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->rx_watermark);
525 sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->tx_empty);
526 sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->rx_overflow);
528 memory_region_init_io(&s->mmio, obj, &ibex_uart_ops, s,
529 TYPE_IBEX_UART, 0x400);
530 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
533 static void ibex_uart_realize(DeviceState *dev, Error **errp)
535 IbexUartState *s = IBEX_UART(dev);
537 s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL,
538 fifo_trigger_update, s);
540 qemu_chr_fe_set_handlers(&s->chr, ibex_uart_can_receive,
541 ibex_uart_receive, NULL, NULL,
542 s, NULL, true);
545 static void ibex_uart_class_init(ObjectClass *klass, void *data)
547 DeviceClass *dc = DEVICE_CLASS(klass);
549 dc->reset = ibex_uart_reset;
550 dc->realize = ibex_uart_realize;
551 dc->vmsd = &vmstate_ibex_uart;
552 device_class_set_props(dc, ibex_uart_properties);
553 set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
556 static const TypeInfo ibex_uart_info = {
557 .name = TYPE_IBEX_UART,
558 .parent = TYPE_SYS_BUS_DEVICE,
559 .instance_size = sizeof(IbexUartState),
560 .instance_init = ibex_uart_init,
561 .class_init = ibex_uart_class_init,
564 static void ibex_uart_register_types(void)
566 type_register_static(&ibex_uart_info);
569 type_init(ibex_uart_register_types)