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.
10 * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
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 "migration/vmstate.h"
27 #include "chardev/char-fe.h"
28 #include "chardev/char-serial.h"
29 #include "qemu/timer.h"
31 #include "qemu/module.h"
32 #include "hw/char/cadence_uart.h"
34 #include "hw/qdev-clock.h"
37 #ifdef CADENCE_UART_ERR_DEBUG
38 #define DB_PRINT(...) do { \
39 fprintf(stderr, ": %s: ", __func__); \
40 fprintf(stderr, ## __VA_ARGS__); \
46 #define UART_SR_INTR_RTRIG 0x00000001
47 #define UART_SR_INTR_REMPTY 0x00000002
48 #define UART_SR_INTR_RFUL 0x00000004
49 #define UART_SR_INTR_TEMPTY 0x00000008
50 #define UART_SR_INTR_TFUL 0x00000010
51 /* somewhat awkwardly, TTRIG is misaligned between SR and ISR */
52 #define UART_SR_TTRIG 0x00002000
53 #define UART_INTR_TTRIG 0x00000400
54 /* bits fields in CSR that correlate to CISR. If any of these bits are set in
55 * SR, then the same bit in CISR is set high too */
56 #define UART_SR_TO_CISR_MASK 0x0000001F
58 #define UART_INTR_ROVR 0x00000020
59 #define UART_INTR_FRAME 0x00000040
60 #define UART_INTR_PARE 0x00000080
61 #define UART_INTR_TIMEOUT 0x00000100
62 #define UART_INTR_DMSI 0x00000200
63 #define UART_INTR_TOVR 0x00001000
65 #define UART_SR_RACTIVE 0x00000400
66 #define UART_SR_TACTIVE 0x00000800
67 #define UART_SR_FDELT 0x00001000
69 #define UART_CR_RXRST 0x00000001
70 #define UART_CR_TXRST 0x00000002
71 #define UART_CR_RX_EN 0x00000004
72 #define UART_CR_RX_DIS 0x00000008
73 #define UART_CR_TX_EN 0x00000010
74 #define UART_CR_TX_DIS 0x00000020
75 #define UART_CR_RST_TO 0x00000040
76 #define UART_CR_STARTBRK 0x00000080
77 #define UART_CR_STOPBRK 0x00000100
79 #define UART_MR_CLKS 0x00000001
80 #define UART_MR_CHRL 0x00000006
81 #define UART_MR_CHRL_SH 1
82 #define UART_MR_PAR 0x00000038
83 #define UART_MR_PAR_SH 3
84 #define UART_MR_NBSTOP 0x000000C0
85 #define UART_MR_NBSTOP_SH 6
86 #define UART_MR_CHMODE 0x00000300
87 #define UART_MR_CHMODE_SH 8
88 #define UART_MR_UCLKEN 0x00000400
89 #define UART_MR_IRMODE 0x00000800
91 #define UART_DATA_BITS_6 (0x3 << UART_MR_CHRL_SH)
92 #define UART_DATA_BITS_7 (0x2 << UART_MR_CHRL_SH)
93 #define UART_PARITY_ODD (0x1 << UART_MR_PAR_SH)
94 #define UART_PARITY_EVEN (0x0 << UART_MR_PAR_SH)
95 #define UART_STOP_BITS_1 (0x3 << UART_MR_NBSTOP_SH)
96 #define UART_STOP_BITS_2 (0x2 << UART_MR_NBSTOP_SH)
97 #define NORMAL_MODE (0x0 << UART_MR_CHMODE_SH)
98 #define ECHO_MODE (0x1 << UART_MR_CHMODE_SH)
99 #define LOCAL_LOOPBACK (0x2 << UART_MR_CHMODE_SH)
100 #define REMOTE_LOOPBACK (0x3 << UART_MR_CHMODE_SH)
102 #define UART_DEFAULT_REF_CLK (50 * 1000 * 1000)
104 #define R_CR (0x00/4)
105 #define R_MR (0x04/4)
106 #define R_IER (0x08/4)
107 #define R_IDR (0x0C/4)
108 #define R_IMR (0x10/4)
109 #define R_CISR (0x14/4)
110 #define R_BRGR (0x18/4)
111 #define R_RTOR (0x1C/4)
112 #define R_RTRIG (0x20/4)
113 #define R_MCR (0x24/4)
114 #define R_MSR (0x28/4)
115 #define R_SR (0x2C/4)
116 #define R_TX_RX (0x30/4)
117 #define R_BDIV (0x34/4)
118 #define R_FDEL (0x38/4)
119 #define R_PMIN (0x3C/4)
120 #define R_PWID (0x40/4)
121 #define R_TTRIG (0x44/4)
124 static void uart_update_status(CadenceUARTState
*s
)
128 s
->r
[R_SR
] |= s
->rx_count
== CADENCE_UART_RX_FIFO_SIZE
? UART_SR_INTR_RFUL
130 s
->r
[R_SR
] |= !s
->rx_count
? UART_SR_INTR_REMPTY
: 0;
131 s
->r
[R_SR
] |= s
->rx_count
>= s
->r
[R_RTRIG
] ? UART_SR_INTR_RTRIG
: 0;
133 s
->r
[R_SR
] |= s
->tx_count
== CADENCE_UART_TX_FIFO_SIZE
? UART_SR_INTR_TFUL
135 s
->r
[R_SR
] |= !s
->tx_count
? UART_SR_INTR_TEMPTY
: 0;
136 s
->r
[R_SR
] |= s
->tx_count
>= s
->r
[R_TTRIG
] ? UART_SR_TTRIG
: 0;
138 s
->r
[R_CISR
] |= s
->r
[R_SR
] & UART_SR_TO_CISR_MASK
;
139 s
->r
[R_CISR
] |= s
->r
[R_SR
] & UART_SR_TTRIG
? UART_INTR_TTRIG
: 0;
140 qemu_set_irq(s
->irq
, !!(s
->r
[R_IMR
] & s
->r
[R_CISR
]));
143 static void fifo_trigger_update(void *opaque
)
145 CadenceUARTState
*s
= opaque
;
148 s
->r
[R_CISR
] |= UART_INTR_TIMEOUT
;
149 uart_update_status(s
);
153 static void uart_rx_reset(CadenceUARTState
*s
)
157 qemu_chr_fe_accept_input(&s
->chr
);
160 static void uart_tx_reset(CadenceUARTState
*s
)
165 static void uart_send_breaks(CadenceUARTState
*s
)
167 int break_enabled
= 1;
169 qemu_chr_fe_ioctl(&s
->chr
, CHR_IOCTL_SERIAL_SET_BREAK
,
173 static void uart_parameters_setup(CadenceUARTState
*s
)
175 QEMUSerialSetParams ssp
;
176 unsigned int baud_rate
, packet_size
, input_clk
;
177 input_clk
= clock_get_hz(s
->refclk
);
179 baud_rate
= (s
->r
[R_MR
] & UART_MR_CLKS
) ? input_clk
/ 8 : input_clk
;
180 baud_rate
/= (s
->r
[R_BRGR
] * (s
->r
[R_BDIV
] + 1));
181 trace_cadence_uart_baudrate(baud_rate
);
183 ssp
.speed
= baud_rate
;
187 switch (s
->r
[R_MR
] & UART_MR_PAR
) {
188 case UART_PARITY_EVEN
:
192 case UART_PARITY_ODD
:
201 switch (s
->r
[R_MR
] & UART_MR_CHRL
) {
202 case UART_DATA_BITS_6
:
205 case UART_DATA_BITS_7
:
213 switch (s
->r
[R_MR
] & UART_MR_NBSTOP
) {
214 case UART_STOP_BITS_1
:
222 packet_size
+= ssp
.data_bits
+ ssp
.stop_bits
;
223 if (ssp
.speed
== 0) {
225 * Avoid division-by-zero below.
226 * TODO: find something better
230 s
->char_tx_time
= (NANOSECONDS_PER_SECOND
/ ssp
.speed
) * packet_size
;
231 qemu_chr_fe_ioctl(&s
->chr
, CHR_IOCTL_SERIAL_SET_PARAMS
, &ssp
);
234 static int uart_can_receive(void *opaque
)
236 CadenceUARTState
*s
= opaque
;
237 int ret
= MAX(CADENCE_UART_RX_FIFO_SIZE
, CADENCE_UART_TX_FIFO_SIZE
);
238 uint32_t ch_mode
= s
->r
[R_MR
] & UART_MR_CHMODE
;
240 if (ch_mode
== NORMAL_MODE
|| ch_mode
== ECHO_MODE
) {
241 ret
= MIN(ret
, CADENCE_UART_RX_FIFO_SIZE
- s
->rx_count
);
243 if (ch_mode
== REMOTE_LOOPBACK
|| ch_mode
== ECHO_MODE
) {
244 ret
= MIN(ret
, CADENCE_UART_TX_FIFO_SIZE
- s
->tx_count
);
249 static void uart_ctrl_update(CadenceUARTState
*s
)
251 if (s
->r
[R_CR
] & UART_CR_TXRST
) {
255 if (s
->r
[R_CR
] & UART_CR_RXRST
) {
259 s
->r
[R_CR
] &= ~(UART_CR_TXRST
| UART_CR_RXRST
);
261 if (s
->r
[R_CR
] & UART_CR_STARTBRK
&& !(s
->r
[R_CR
] & UART_CR_STOPBRK
)) {
266 static void uart_write_rx_fifo(void *opaque
, const uint8_t *buf
, int size
)
268 CadenceUARTState
*s
= opaque
;
269 uint64_t new_rx_time
= qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
);
272 if ((s
->r
[R_CR
] & UART_CR_RX_DIS
) || !(s
->r
[R_CR
] & UART_CR_RX_EN
)) {
276 if (s
->rx_count
== CADENCE_UART_RX_FIFO_SIZE
) {
277 s
->r
[R_CISR
] |= UART_INTR_ROVR
;
279 for (i
= 0; i
< size
; i
++) {
280 s
->rx_fifo
[s
->rx_wpos
] = buf
[i
];
281 s
->rx_wpos
= (s
->rx_wpos
+ 1) % CADENCE_UART_RX_FIFO_SIZE
;
284 timer_mod(s
->fifo_trigger_handle
, new_rx_time
+
285 (s
->char_tx_time
* 4));
287 uart_update_status(s
);
290 static gboolean
cadence_uart_xmit(GIOChannel
*chan
, GIOCondition cond
,
293 CadenceUARTState
*s
= opaque
;
296 /* instant drain the fifo when there's no back-end */
297 if (!qemu_chr_fe_backend_connected(&s
->chr
)) {
306 ret
= qemu_chr_fe_write(&s
->chr
, s
->tx_fifo
, s
->tx_count
);
310 memmove(s
->tx_fifo
, s
->tx_fifo
+ ret
, s
->tx_count
);
314 guint r
= qemu_chr_fe_add_watch(&s
->chr
, G_IO_OUT
| G_IO_HUP
,
315 cadence_uart_xmit
, s
);
322 uart_update_status(s
);
326 static void uart_write_tx_fifo(CadenceUARTState
*s
, const uint8_t *buf
,
329 if ((s
->r
[R_CR
] & UART_CR_TX_DIS
) || !(s
->r
[R_CR
] & UART_CR_TX_EN
)) {
333 if (size
> CADENCE_UART_TX_FIFO_SIZE
- s
->tx_count
) {
334 size
= CADENCE_UART_TX_FIFO_SIZE
- s
->tx_count
;
336 * This can only be a guest error via a bad tx fifo register push,
337 * as can_receive() should stop remote loop and echo modes ever getting
340 qemu_log_mask(LOG_GUEST_ERROR
, "cadence_uart: TxFIFO overflow");
341 s
->r
[R_CISR
] |= UART_INTR_ROVR
;
344 memcpy(s
->tx_fifo
+ s
->tx_count
, buf
, size
);
347 cadence_uart_xmit(NULL
, G_IO_OUT
, s
);
350 static void uart_receive(void *opaque
, const uint8_t *buf
, int size
)
352 CadenceUARTState
*s
= opaque
;
353 uint32_t ch_mode
= s
->r
[R_MR
] & UART_MR_CHMODE
;
355 /* ignore characters when unclocked or in reset */
356 if (!clock_is_enabled(s
->refclk
) || device_is_in_reset(DEVICE(s
))) {
360 if (ch_mode
== NORMAL_MODE
|| ch_mode
== ECHO_MODE
) {
361 uart_write_rx_fifo(opaque
, buf
, size
);
363 if (ch_mode
== REMOTE_LOOPBACK
|| ch_mode
== ECHO_MODE
) {
364 uart_write_tx_fifo(s
, buf
, size
);
368 static void uart_event(void *opaque
, QEMUChrEvent event
)
370 CadenceUARTState
*s
= opaque
;
373 /* ignore characters when unclocked or in reset */
374 if (!clock_is_enabled(s
->refclk
) || device_is_in_reset(DEVICE(s
))) {
378 if (event
== CHR_EVENT_BREAK
) {
379 uart_write_rx_fifo(opaque
, &buf
, 1);
382 uart_update_status(s
);
385 static void uart_read_rx_fifo(CadenceUARTState
*s
, uint32_t *c
)
387 if ((s
->r
[R_CR
] & UART_CR_RX_DIS
) || !(s
->r
[R_CR
] & UART_CR_RX_EN
)) {
392 uint32_t rx_rpos
= (CADENCE_UART_RX_FIFO_SIZE
+ s
->rx_wpos
-
393 s
->rx_count
) % CADENCE_UART_RX_FIFO_SIZE
;
394 *c
= s
->rx_fifo
[rx_rpos
];
397 qemu_chr_fe_accept_input(&s
->chr
);
402 uart_update_status(s
);
405 static void uart_write(void *opaque
, hwaddr offset
,
406 uint64_t value
, unsigned size
)
408 CadenceUARTState
*s
= opaque
;
410 DB_PRINT(" offset:%x data:%08x\n", (unsigned)offset
, (unsigned)value
);
412 if (offset
>= CADENCE_UART_R_MAX
) {
416 case R_IER
: /* ier (wts imr) */
417 s
->r
[R_IMR
] |= value
;
419 case R_IDR
: /* idr (wtc imr) */
420 s
->r
[R_IMR
] &= ~value
;
422 case R_IMR
: /* imr (read only) */
424 case R_CISR
: /* cisr (wtc) */
425 s
->r
[R_CISR
] &= ~value
;
427 case R_TX_RX
: /* UARTDR */
428 switch (s
->r
[R_MR
] & UART_MR_CHMODE
) {
430 uart_write_tx_fifo(s
, (uint8_t *) &value
, 1);
433 uart_write_rx_fifo(opaque
, (uint8_t *) &value
, 1);
437 case R_BRGR
: /* Baud rate generator */
439 s
->r
[offset
] = value
& 0xFFFF;
442 case R_BDIV
: /* Baud rate divider */
444 s
->r
[offset
] = value
& 0xFF;
448 s
->r
[offset
] = value
;
456 uart_parameters_setup(s
);
459 uart_update_status(s
);
462 static uint64_t uart_read(void *opaque
, hwaddr offset
,
465 CadenceUARTState
*s
= opaque
;
469 if (offset
>= CADENCE_UART_R_MAX
) {
471 } else if (offset
== R_TX_RX
) {
472 uart_read_rx_fifo(s
, &c
);
477 DB_PRINT(" offset:%x data:%08x\n", (unsigned)(offset
<< 2), (unsigned)c
);
481 static const MemoryRegionOps uart_ops
= {
484 .endianness
= DEVICE_NATIVE_ENDIAN
,
487 static void cadence_uart_reset_init(Object
*obj
, ResetType type
)
489 CadenceUARTState
*s
= CADENCE_UART(obj
);
491 s
->r
[R_CR
] = 0x00000128;
494 s
->r
[R_RTRIG
] = 0x00000020;
495 s
->r
[R_BRGR
] = 0x0000028B;
496 s
->r
[R_BDIV
] = 0x0000000F;
497 s
->r
[R_TTRIG
] = 0x00000020;
500 static void cadence_uart_reset_hold(Object
*obj
)
502 CadenceUARTState
*s
= CADENCE_UART(obj
);
507 uart_update_status(s
);
510 static void cadence_uart_realize(DeviceState
*dev
, Error
**errp
)
512 CadenceUARTState
*s
= CADENCE_UART(dev
);
514 s
->fifo_trigger_handle
= timer_new_ns(QEMU_CLOCK_VIRTUAL
,
515 fifo_trigger_update
, s
);
517 qemu_chr_fe_set_handlers(&s
->chr
, uart_can_receive
, uart_receive
,
518 uart_event
, NULL
, s
, NULL
, true);
521 static void cadence_uart_refclk_update(void *opaque
)
523 CadenceUARTState
*s
= opaque
;
525 /* recompute uart's speed on clock change */
526 uart_parameters_setup(s
);
529 static void cadence_uart_init(Object
*obj
)
531 SysBusDevice
*sbd
= SYS_BUS_DEVICE(obj
);
532 CadenceUARTState
*s
= CADENCE_UART(obj
);
534 memory_region_init_io(&s
->iomem
, obj
, &uart_ops
, s
, "uart", 0x1000);
535 sysbus_init_mmio(sbd
, &s
->iomem
);
536 sysbus_init_irq(sbd
, &s
->irq
);
538 s
->refclk
= qdev_init_clock_in(DEVICE(obj
), "refclk",
539 cadence_uart_refclk_update
, s
);
540 /* initialize the frequency in case the clock remains unconnected */
541 clock_set_hz(s
->refclk
, UART_DEFAULT_REF_CLK
);
543 s
->char_tx_time
= (NANOSECONDS_PER_SECOND
/ 9600) * 10;
546 static int cadence_uart_pre_load(void *opaque
)
548 CadenceUARTState
*s
= opaque
;
550 /* the frequency will be overriden if the refclk field is present */
551 clock_set_hz(s
->refclk
, UART_DEFAULT_REF_CLK
);
555 static int cadence_uart_post_load(void *opaque
, int version_id
)
557 CadenceUARTState
*s
= opaque
;
559 /* Ensure these two aren't invalid numbers */
560 if (s
->r
[R_BRGR
] < 1 || s
->r
[R_BRGR
] & ~0xFFFF ||
561 s
->r
[R_BDIV
] <= 3 || s
->r
[R_BDIV
] & ~0xFF) {
562 /* Value is invalid, abort */
566 uart_parameters_setup(s
);
567 uart_update_status(s
);
571 static const VMStateDescription vmstate_cadence_uart
= {
572 .name
= "cadence_uart",
574 .minimum_version_id
= 2,
575 .pre_load
= cadence_uart_pre_load
,
576 .post_load
= cadence_uart_post_load
,
577 .fields
= (VMStateField
[]) {
578 VMSTATE_UINT32_ARRAY(r
, CadenceUARTState
, CADENCE_UART_R_MAX
),
579 VMSTATE_UINT8_ARRAY(rx_fifo
, CadenceUARTState
,
580 CADENCE_UART_RX_FIFO_SIZE
),
581 VMSTATE_UINT8_ARRAY(tx_fifo
, CadenceUARTState
,
582 CADENCE_UART_TX_FIFO_SIZE
),
583 VMSTATE_UINT32(rx_count
, CadenceUARTState
),
584 VMSTATE_UINT32(tx_count
, CadenceUARTState
),
585 VMSTATE_UINT32(rx_wpos
, CadenceUARTState
),
586 VMSTATE_TIMER_PTR(fifo_trigger_handle
, CadenceUARTState
),
587 VMSTATE_CLOCK_V(refclk
, CadenceUARTState
, 3),
588 VMSTATE_END_OF_LIST()
592 static Property cadence_uart_properties
[] = {
593 DEFINE_PROP_CHR("chardev", CadenceUARTState
, chr
),
594 DEFINE_PROP_END_OF_LIST(),
597 static void cadence_uart_class_init(ObjectClass
*klass
, void *data
)
599 DeviceClass
*dc
= DEVICE_CLASS(klass
);
600 ResettableClass
*rc
= RESETTABLE_CLASS(klass
);
602 dc
->realize
= cadence_uart_realize
;
603 dc
->vmsd
= &vmstate_cadence_uart
;
604 rc
->phases
.enter
= cadence_uart_reset_init
;
605 rc
->phases
.hold
= cadence_uart_reset_hold
;
606 device_class_set_props(dc
, cadence_uart_properties
);
609 static const TypeInfo cadence_uart_info
= {
610 .name
= TYPE_CADENCE_UART
,
611 .parent
= TYPE_SYS_BUS_DEVICE
,
612 .instance_size
= sizeof(CadenceUARTState
),
613 .instance_init
= cadence_uart_init
,
614 .class_init
= cadence_uart_class_init
,
617 static void cadence_uart_register_types(void)
619 type_register_static(&cadence_uart_info
);
622 type_init(cadence_uart_register_types
)