xref: /openbmc/qemu/hw/ssi/ibex_spi_host.c (revision 3d54cbf2)
1 /*
2  * QEMU model of the Ibex SPI Controller
3  * SPEC Reference: https://docs.opentitan.org/hw/ip/spi_host/doc/
4  *
5  * Copyright (C) 2022 Western Digital
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "qemu/log.h"
28 #include "qemu/module.h"
29 #include "hw/registerfields.h"
30 #include "hw/ssi/ibex_spi_host.h"
31 #include "hw/irq.h"
32 #include "hw/qdev-properties.h"
33 #include "hw/qdev-properties-system.h"
34 #include "migration/vmstate.h"
35 #include "trace.h"
36 
37 REG32(INTR_STATE, 0x00)
38     FIELD(INTR_STATE, ERROR, 0, 1)
39     FIELD(INTR_STATE, SPI_EVENT, 1, 1)
40 REG32(INTR_ENABLE, 0x04)
41     FIELD(INTR_ENABLE, ERROR, 0, 1)
42     FIELD(INTR_ENABLE, SPI_EVENT, 1, 1)
43 REG32(INTR_TEST, 0x08)
44     FIELD(INTR_TEST, ERROR, 0, 1)
45     FIELD(INTR_TEST, SPI_EVENT, 1, 1)
46 REG32(ALERT_TEST, 0x0c)
47     FIELD(ALERT_TEST, FETAL_TEST, 0, 1)
48 REG32(CONTROL, 0x10)
49     FIELD(CONTROL, RX_WATERMARK, 0, 8)
50     FIELD(CONTROL, TX_WATERMARK, 1, 8)
51     FIELD(CONTROL, OUTPUT_EN, 29, 1)
52     FIELD(CONTROL, SW_RST, 30, 1)
53     FIELD(CONTROL, SPIEN, 31, 1)
54 REG32(STATUS, 0x14)
55     FIELD(STATUS, TXQD, 0, 8)
56     FIELD(STATUS, RXQD, 18, 8)
57     FIELD(STATUS, CMDQD, 16, 3)
58     FIELD(STATUS, RXWM, 20, 1)
59     FIELD(STATUS, BYTEORDER, 22, 1)
60     FIELD(STATUS, RXSTALL, 23, 1)
61     FIELD(STATUS, RXEMPTY, 24, 1)
62     FIELD(STATUS, RXFULL, 25, 1)
63     FIELD(STATUS, TXWM, 26, 1)
64     FIELD(STATUS, TXSTALL, 27, 1)
65     FIELD(STATUS, TXEMPTY, 28, 1)
66     FIELD(STATUS, TXFULL, 29, 1)
67     FIELD(STATUS, ACTIVE, 30, 1)
68     FIELD(STATUS, READY, 31, 1)
69 REG32(CONFIGOPTS, 0x18)
70     FIELD(CONFIGOPTS, CLKDIV_0, 0, 16)
71     FIELD(CONFIGOPTS, CSNIDLE_0, 16, 4)
72     FIELD(CONFIGOPTS, CSNTRAIL_0, 20, 4)
73     FIELD(CONFIGOPTS, CSNLEAD_0, 24, 4)
74     FIELD(CONFIGOPTS, FULLCYC_0, 29, 1)
75     FIELD(CONFIGOPTS, CPHA_0, 30, 1)
76     FIELD(CONFIGOPTS, CPOL_0, 31, 1)
77 REG32(CSID, 0x1c)
78     FIELD(CSID, CSID, 0, 32)
79 REG32(COMMAND, 0x20)
80     FIELD(COMMAND, LEN, 0, 8)
81     FIELD(COMMAND, CSAAT, 9, 1)
82     FIELD(COMMAND, SPEED, 10, 2)
83     FIELD(COMMAND, DIRECTION, 12, 2)
84 REG32(ERROR_ENABLE, 0x2c)
85     FIELD(ERROR_ENABLE, CMDBUSY, 0, 1)
86     FIELD(ERROR_ENABLE, OVERFLOW, 1, 1)
87     FIELD(ERROR_ENABLE, UNDERFLOW, 2, 1)
88     FIELD(ERROR_ENABLE, CMDINVAL, 3, 1)
89     FIELD(ERROR_ENABLE, CSIDINVAL, 4, 1)
90 REG32(ERROR_STATUS, 0x30)
91     FIELD(ERROR_STATUS, CMDBUSY, 0, 1)
92     FIELD(ERROR_STATUS, OVERFLOW, 1, 1)
93     FIELD(ERROR_STATUS, UNDERFLOW, 2, 1)
94     FIELD(ERROR_STATUS, CMDINVAL, 3, 1)
95     FIELD(ERROR_STATUS, CSIDINVAL, 4, 1)
96     FIELD(ERROR_STATUS, ACCESSINVAL, 5, 1)
97 REG32(EVENT_ENABLE, 0x34)
98     FIELD(EVENT_ENABLE, RXFULL, 0, 1)
99     FIELD(EVENT_ENABLE, TXEMPTY, 1, 1)
100     FIELD(EVENT_ENABLE, RXWM, 2, 1)
101     FIELD(EVENT_ENABLE, TXWM, 3, 1)
102     FIELD(EVENT_ENABLE, READY, 4, 1)
103     FIELD(EVENT_ENABLE, IDLE, 5, 1)
104 
105 static inline uint8_t div4_round_up(uint8_t dividend)
106 {
107     return (dividend + 3) / 4;
108 }
109 
110 static void ibex_spi_rxfifo_reset(IbexSPIHostState *s)
111 {
112     uint32_t data = s->regs[IBEX_SPI_HOST_STATUS];
113     /* Empty the RX FIFO and assert RXEMPTY */
114     fifo8_reset(&s->rx_fifo);
115     data = FIELD_DP32(data, STATUS, RXFULL, 0);
116     data = FIELD_DP32(data, STATUS, RXEMPTY, 1);
117     s->regs[IBEX_SPI_HOST_STATUS] = data;
118 }
119 
120 static void ibex_spi_txfifo_reset(IbexSPIHostState *s)
121 {
122     uint32_t data = s->regs[IBEX_SPI_HOST_STATUS];
123     /* Empty the TX FIFO and assert TXEMPTY */
124     fifo8_reset(&s->tx_fifo);
125     data = FIELD_DP32(data, STATUS, TXFULL, 0);
126     data = FIELD_DP32(data, STATUS, TXEMPTY, 1);
127     s->regs[IBEX_SPI_HOST_STATUS] = data;
128 }
129 
130 static void ibex_spi_host_reset(DeviceState *dev)
131 {
132     IbexSPIHostState *s = IBEX_SPI_HOST(dev);
133     trace_ibex_spi_host_reset("Resetting Ibex SPI");
134 
135     /* SPI Host Register Reset */
136     s->regs[IBEX_SPI_HOST_INTR_STATE]   = 0x00;
137     s->regs[IBEX_SPI_HOST_INTR_ENABLE]  = 0x00;
138     s->regs[IBEX_SPI_HOST_INTR_TEST]    = 0x00;
139     s->regs[IBEX_SPI_HOST_ALERT_TEST]   = 0x00;
140     s->regs[IBEX_SPI_HOST_CONTROL]      = 0x7f;
141     s->regs[IBEX_SPI_HOST_STATUS]       = 0x00;
142     s->regs[IBEX_SPI_HOST_CONFIGOPTS]   = 0x00;
143     s->regs[IBEX_SPI_HOST_CSID]         = 0x00;
144     s->regs[IBEX_SPI_HOST_COMMAND]      = 0x00;
145     /* RX/TX Modelled by FIFO */
146     s->regs[IBEX_SPI_HOST_RXDATA]       = 0x00;
147     s->regs[IBEX_SPI_HOST_TXDATA]       = 0x00;
148 
149     s->regs[IBEX_SPI_HOST_ERROR_ENABLE] = 0x1F;
150     s->regs[IBEX_SPI_HOST_ERROR_STATUS] = 0x00;
151     s->regs[IBEX_SPI_HOST_EVENT_ENABLE] = 0x00;
152 
153     ibex_spi_rxfifo_reset(s);
154     ibex_spi_txfifo_reset(s);
155 
156     s->init_status = true;
157     return;
158 }
159 
160 /*
161  * Check if we need to trigger an interrupt.
162  * The two interrupts lines (host_err and event) can
163  * be enabled separately in 'IBEX_SPI_HOST_INTR_ENABLE'.
164  *
165  * Interrupts are triggered based on the ones
166  * enabled in the `IBEX_SPI_HOST_EVENT_ENABLE` and `IBEX_SPI_HOST_ERROR_ENABLE`.
167  */
168 static void ibex_spi_host_irq(IbexSPIHostState *s)
169 {
170     uint32_t intr_test_reg = s->regs[IBEX_SPI_HOST_INTR_TEST];
171     uint32_t intr_en_reg = s->regs[IBEX_SPI_HOST_INTR_ENABLE];
172     uint32_t intr_state_reg = s->regs[IBEX_SPI_HOST_INTR_STATE];
173 
174     uint32_t err_en_reg = s->regs[IBEX_SPI_HOST_ERROR_ENABLE];
175     uint32_t event_en_reg = s->regs[IBEX_SPI_HOST_EVENT_ENABLE];
176     uint32_t err_status_reg = s->regs[IBEX_SPI_HOST_ERROR_STATUS];
177     uint32_t status_reg = s->regs[IBEX_SPI_HOST_STATUS];
178 
179 
180     bool error_en = FIELD_EX32(intr_en_reg, INTR_ENABLE, ERROR);
181     bool event_en = FIELD_EX32(intr_en_reg, INTR_ENABLE, SPI_EVENT);
182     bool err_pending = FIELD_EX32(intr_state_reg, INTR_STATE, ERROR);
183     bool status_pending = FIELD_EX32(intr_state_reg, INTR_STATE, SPI_EVENT);
184 
185     int err_irq = 0, event_irq = 0;
186 
187     /* Error IRQ enabled and Error IRQ Cleared */
188     if (error_en && !err_pending) {
189         /* Event enabled, Interrupt Test Error */
190         if (FIELD_EX32(intr_test_reg, INTR_TEST,  ERROR)) {
191             err_irq = 1;
192         } else if (FIELD_EX32(err_en_reg, ERROR_ENABLE,  CMDBUSY) &&
193                    FIELD_EX32(err_status_reg, ERROR_STATUS,  CMDBUSY)) {
194             /* Wrote to COMMAND when not READY */
195             err_irq = 1;
196         } else if (FIELD_EX32(err_en_reg, ERROR_ENABLE,  CMDINVAL)  &&
197                    FIELD_EX32(err_status_reg, ERROR_STATUS,  CMDINVAL)) {
198             /* Invalid command segment */
199             err_irq = 1;
200         } else if (FIELD_EX32(err_en_reg, ERROR_ENABLE,  CSIDINVAL) &&
201                    FIELD_EX32(err_status_reg, ERROR_STATUS,  CSIDINVAL)) {
202             /* Invalid value for CSID */
203             err_irq = 1;
204         }
205         if (err_irq) {
206             s->regs[IBEX_SPI_HOST_INTR_STATE] |= R_INTR_STATE_ERROR_MASK;
207         }
208     }
209 
210     qemu_set_irq(s->host_err, err_irq);
211 
212     /* Event IRQ Enabled and Event IRQ Cleared */
213     if (event_en && !status_pending) {
214         if (FIELD_EX32(intr_test_reg, INTR_STATE,  SPI_EVENT)) {
215             /* Event enabled, Interrupt Test Event */
216             event_irq = 1;
217         } else if (FIELD_EX32(event_en_reg, EVENT_ENABLE,  READY) &&
218                    FIELD_EX32(status_reg, STATUS, READY)) {
219             /* SPI Host ready for next command */
220             event_irq = 1;
221         } else if (FIELD_EX32(event_en_reg, EVENT_ENABLE,  TXEMPTY) &&
222                    FIELD_EX32(status_reg, STATUS,  TXEMPTY)) {
223             /* SPI TXEMPTY, TXFIFO drained */
224             event_irq = 1;
225         } else if (FIELD_EX32(event_en_reg, EVENT_ENABLE,  RXFULL) &&
226                    FIELD_EX32(status_reg, STATUS,  RXFULL)) {
227             /* SPI RXFULL, RXFIFO  full */
228             event_irq = 1;
229         }
230         if (event_irq) {
231             s->regs[IBEX_SPI_HOST_INTR_STATE] |= R_INTR_STATE_SPI_EVENT_MASK;
232         }
233     }
234 
235     qemu_set_irq(s->event, event_irq);
236 }
237 
238 static void ibex_spi_host_transfer(IbexSPIHostState *s)
239 {
240     uint32_t rx, tx, data;
241     /* Get num of one byte transfers */
242     uint8_t segment_len = FIELD_EX32(s->regs[IBEX_SPI_HOST_COMMAND],
243                                      COMMAND,  LEN);
244 
245     while (segment_len > 0) {
246         if (fifo8_is_empty(&s->tx_fifo)) {
247             /* Assert Stall */
248             s->regs[IBEX_SPI_HOST_STATUS] |= R_STATUS_TXSTALL_MASK;
249             break;
250         } else if (fifo8_is_full(&s->rx_fifo)) {
251             /* Assert Stall */
252             s->regs[IBEX_SPI_HOST_STATUS] |= R_STATUS_RXSTALL_MASK;
253             break;
254         } else {
255             tx = fifo8_pop(&s->tx_fifo);
256         }
257 
258         rx = ssi_transfer(s->ssi, tx);
259 
260         trace_ibex_spi_host_transfer(tx, rx);
261 
262         if (!fifo8_is_full(&s->rx_fifo)) {
263             fifo8_push(&s->rx_fifo, rx);
264         } else {
265             /* Assert RXFULL */
266             s->regs[IBEX_SPI_HOST_STATUS] |= R_STATUS_RXFULL_MASK;
267         }
268         --segment_len;
269     }
270 
271     data = s->regs[IBEX_SPI_HOST_STATUS];
272     /* Assert Ready */
273     data = FIELD_DP32(data, STATUS, READY, 1);
274     /* Set RXQD */
275     data = FIELD_DP32(data, STATUS, RXQD, div4_round_up(segment_len));
276     /* Set TXQD */
277     data = FIELD_DP32(data, STATUS, TXQD, fifo8_num_used(&s->tx_fifo) / 4);
278     /* Clear TXFULL */
279     data = FIELD_DP32(data, STATUS, TXFULL, 0);
280     /* Reset RXEMPTY */
281     data = FIELD_DP32(data, STATUS, RXEMPTY, 0);
282     /* Update register status */
283     s->regs[IBEX_SPI_HOST_STATUS] = data;
284     /* Drop remaining bytes that exceed segment_len */
285     ibex_spi_txfifo_reset(s);
286 
287     ibex_spi_host_irq(s);
288 }
289 
290 static uint64_t ibex_spi_host_read(void *opaque, hwaddr addr,
291                                      unsigned int size)
292 {
293     IbexSPIHostState *s = opaque;
294     uint32_t rc = 0;
295     uint8_t rx_byte = 0;
296 
297     trace_ibex_spi_host_read(addr, size);
298 
299     /* Match reg index */
300     addr = addr >> 2;
301     switch (addr) {
302     /* Skipping any W/O registers */
303     case IBEX_SPI_HOST_INTR_STATE...IBEX_SPI_HOST_INTR_ENABLE:
304     case IBEX_SPI_HOST_CONTROL...IBEX_SPI_HOST_STATUS:
305         rc = s->regs[addr];
306         break;
307     case IBEX_SPI_HOST_CSID:
308         rc = s->regs[addr];
309         break;
310     case IBEX_SPI_HOST_CONFIGOPTS:
311         rc = s->config_opts[s->regs[IBEX_SPI_HOST_CSID]];
312         break;
313     case IBEX_SPI_HOST_TXDATA:
314         rc = s->regs[addr];
315         break;
316     case IBEX_SPI_HOST_RXDATA:
317         /* Clear RXFULL */
318         s->regs[IBEX_SPI_HOST_STATUS] &= ~R_STATUS_RXFULL_MASK;
319 
320         for (int i = 0; i < 4; ++i) {
321             if (fifo8_is_empty(&s->rx_fifo)) {
322                 /* Assert RXEMPTY, no IRQ */
323                 s->regs[IBEX_SPI_HOST_STATUS] |= R_STATUS_RXEMPTY_MASK;
324                 s->regs[IBEX_SPI_HOST_ERROR_STATUS] |=
325                                                 R_ERROR_STATUS_UNDERFLOW_MASK;
326                 return rc;
327             }
328             rx_byte = fifo8_pop(&s->rx_fifo);
329             rc |= rx_byte << (i * 8);
330         }
331         break;
332     case IBEX_SPI_HOST_ERROR_ENABLE...IBEX_SPI_HOST_EVENT_ENABLE:
333         rc = s->regs[addr];
334         break;
335     default:
336         qemu_log_mask(LOG_GUEST_ERROR, "Bad offset 0x%" HWADDR_PRIx "\n",
337                       addr << 2);
338     }
339     return rc;
340 }
341 
342 
343 static void ibex_spi_host_write(void *opaque, hwaddr addr,
344                                 uint64_t val64, unsigned int size)
345 {
346     IbexSPIHostState *s = opaque;
347     uint32_t val32 = val64;
348     uint32_t shift_mask = 0xff, status = 0, data = 0;
349     uint8_t txqd_len;
350 
351     trace_ibex_spi_host_write(addr, size, val64);
352 
353     /* Match reg index */
354     addr = addr >> 2;
355 
356     switch (addr) {
357     /* Skipping any R/O registers */
358     case IBEX_SPI_HOST_INTR_STATE:
359         /* rw1c status register */
360         if (FIELD_EX32(val32, INTR_STATE, ERROR)) {
361             data = FIELD_DP32(data, INTR_STATE, ERROR, 0);
362         }
363         if (FIELD_EX32(val32, INTR_STATE, SPI_EVENT)) {
364             data = FIELD_DP32(data, INTR_STATE, SPI_EVENT, 0);
365         }
366         s->regs[addr] = data;
367         break;
368     case IBEX_SPI_HOST_INTR_ENABLE:
369         s->regs[addr] = val32;
370         break;
371     case IBEX_SPI_HOST_INTR_TEST:
372         s->regs[addr] = val32;
373         ibex_spi_host_irq(s);
374         break;
375     case IBEX_SPI_HOST_ALERT_TEST:
376         s->regs[addr] = val32;
377         qemu_log_mask(LOG_UNIMP,
378                         "%s: SPI_ALERT_TEST is not supported\n", __func__);
379         break;
380     case IBEX_SPI_HOST_CONTROL:
381         s->regs[addr] = val32;
382 
383         if (val32 & R_CONTROL_SW_RST_MASK)  {
384             ibex_spi_host_reset((DeviceState *)s);
385             /* Clear active if any */
386             s->regs[IBEX_SPI_HOST_STATUS] &=  ~R_STATUS_ACTIVE_MASK;
387         }
388 
389         if (val32 & R_CONTROL_OUTPUT_EN_MASK)  {
390             qemu_log_mask(LOG_UNIMP,
391                           "%s: CONTROL_OUTPUT_EN is not supported\n", __func__);
392         }
393         break;
394     case IBEX_SPI_HOST_CONFIGOPTS:
395         /* Update the respective config-opts register based on CSIDth index */
396         s->config_opts[s->regs[IBEX_SPI_HOST_CSID]] = val32;
397         qemu_log_mask(LOG_UNIMP,
398                       "%s: CONFIGOPTS Hardware settings not supported\n",
399                          __func__);
400         break;
401     case IBEX_SPI_HOST_CSID:
402         if (val32 >= s->num_cs) {
403             /* CSID exceeds max num_cs */
404             s->regs[IBEX_SPI_HOST_ERROR_STATUS] |=
405                                                 R_ERROR_STATUS_CSIDINVAL_MASK;
406             ibex_spi_host_irq(s);
407             return;
408         }
409         s->regs[addr] = val32;
410         break;
411     case IBEX_SPI_HOST_COMMAND:
412         s->regs[addr] = val32;
413 
414         /* STALL, IP not enabled */
415         if (!(FIELD_EX32(s->regs[IBEX_SPI_HOST_CONTROL],
416                          CONTROL, SPIEN))) {
417             return;
418         }
419 
420         /* SPI not ready, IRQ Error */
421         if (!(FIELD_EX32(s->regs[IBEX_SPI_HOST_STATUS],
422                          STATUS, READY))) {
423             s->regs[IBEX_SPI_HOST_ERROR_STATUS] |= R_ERROR_STATUS_CMDBUSY_MASK;
424             ibex_spi_host_irq(s);
425             return;
426         }
427 
428         /* Assert Not Ready */
429         s->regs[IBEX_SPI_HOST_STATUS] &= ~R_STATUS_READY_MASK;
430 
431         if (FIELD_EX32(val32, COMMAND, DIRECTION) != BIDIRECTIONAL_TRANSFER) {
432             qemu_log_mask(LOG_UNIMP,
433                           "%s: Rx Only/Tx Only are not supported\n", __func__);
434         }
435 
436         if (val32 & R_COMMAND_CSAAT_MASK)  {
437             qemu_log_mask(LOG_UNIMP,
438                           "%s: CSAAT is not supported\n", __func__);
439         }
440         if (val32 & R_COMMAND_SPEED_MASK)  {
441             qemu_log_mask(LOG_UNIMP,
442                           "%s: SPEED is not supported\n", __func__);
443         }
444 
445         /* Set Transfer Callback */
446         timer_mod(s->fifo_trigger_handle,
447                     qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
448                     (TX_INTERRUPT_TRIGGER_DELAY_NS));
449 
450         break;
451     case IBEX_SPI_HOST_TXDATA:
452         /*
453          * This is a hardware `feature` where
454          * the first word written to TXDATA after init is omitted entirely
455          */
456         if (s->init_status) {
457             s->init_status = false;
458             return;
459         }
460 
461         for (int i = 0; i < 4; ++i) {
462             /* Attempting to write when TXFULL */
463             if (fifo8_is_full(&s->tx_fifo)) {
464                 /* Assert RXEMPTY, no IRQ */
465                 s->regs[IBEX_SPI_HOST_STATUS] |= R_STATUS_TXFULL_MASK;
466                 s->regs[IBEX_SPI_HOST_ERROR_STATUS] |=
467                                                  R_ERROR_STATUS_OVERFLOW_MASK;
468                 ibex_spi_host_irq(s);
469                 return;
470             }
471             /* Byte ordering is set by the IP */
472             status = s->regs[IBEX_SPI_HOST_STATUS];
473             if (FIELD_EX32(status, STATUS, BYTEORDER) == 0) {
474                 /* LE: LSB transmitted first (default for ibex processor) */
475                 shift_mask = 0xff << (i * 8);
476             } else {
477                 /* BE: MSB transmitted first */
478                 qemu_log_mask(LOG_UNIMP,
479                              "%s: Big endian is not supported\n", __func__);
480             }
481 
482             fifo8_push(&s->tx_fifo, (val32 & shift_mask) >> (i * 8));
483         }
484         status = s->regs[IBEX_SPI_HOST_STATUS];
485         /* Reset TXEMPTY */
486         status = FIELD_DP32(status, STATUS, TXEMPTY, 0);
487         /* Update TXQD */
488         txqd_len = FIELD_EX32(status, STATUS, TXQD);
489         /* Partial bytes (size < 4) are padded, in words. */
490         txqd_len += 1;
491         status = FIELD_DP32(status, STATUS, TXQD, txqd_len);
492         /* Assert Ready */
493         status = FIELD_DP32(status, STATUS, READY, 1);
494         /* Update register status */
495         s->regs[IBEX_SPI_HOST_STATUS] = status;
496         break;
497     case IBEX_SPI_HOST_ERROR_ENABLE:
498         s->regs[addr] = val32;
499 
500         if (val32 & R_ERROR_ENABLE_CMDINVAL_MASK)  {
501             qemu_log_mask(LOG_UNIMP,
502                           "%s: Segment Length is not supported\n", __func__);
503         }
504         break;
505     case IBEX_SPI_HOST_ERROR_STATUS:
506     /*
507      *  Indicates any errors that have occurred.
508      *  When an error occurs, the corresponding bit must be cleared
509      *  here before issuing any further commands
510      */
511         status = s->regs[addr];
512         /* rw1c status register */
513         if (FIELD_EX32(val32, ERROR_STATUS, CMDBUSY)) {
514             status = FIELD_DP32(status, ERROR_STATUS, CMDBUSY, 0);
515         }
516         if (FIELD_EX32(val32, ERROR_STATUS, OVERFLOW)) {
517             status = FIELD_DP32(status, ERROR_STATUS, OVERFLOW, 0);
518         }
519         if (FIELD_EX32(val32, ERROR_STATUS, UNDERFLOW)) {
520             status = FIELD_DP32(status, ERROR_STATUS, UNDERFLOW, 0);
521         }
522         if (FIELD_EX32(val32, ERROR_STATUS, CMDINVAL)) {
523             status = FIELD_DP32(status, ERROR_STATUS, CMDINVAL, 0);
524         }
525         if (FIELD_EX32(val32, ERROR_STATUS, CSIDINVAL)) {
526             status = FIELD_DP32(status, ERROR_STATUS, CSIDINVAL, 0);
527         }
528         if (FIELD_EX32(val32, ERROR_STATUS, ACCESSINVAL)) {
529             status = FIELD_DP32(status, ERROR_STATUS, ACCESSINVAL, 0);
530         }
531         s->regs[addr] = status;
532         break;
533     case IBEX_SPI_HOST_EVENT_ENABLE:
534     /* Controls which classes of SPI events raise an interrupt. */
535         s->regs[addr] = val32;
536 
537         if (val32 & R_EVENT_ENABLE_RXWM_MASK)  {
538             qemu_log_mask(LOG_UNIMP,
539                           "%s: RXWM is not supported\n", __func__);
540         }
541         if (val32 & R_EVENT_ENABLE_TXWM_MASK)  {
542             qemu_log_mask(LOG_UNIMP,
543                           "%s: TXWM is not supported\n", __func__);
544         }
545 
546         if (val32 & R_EVENT_ENABLE_IDLE_MASK)  {
547             qemu_log_mask(LOG_UNIMP,
548                           "%s: IDLE is not supported\n", __func__);
549         }
550         break;
551     default:
552         qemu_log_mask(LOG_GUEST_ERROR, "Bad offset 0x%" HWADDR_PRIx "\n",
553                       addr << 2);
554     }
555 }
556 
557 static const MemoryRegionOps ibex_spi_ops = {
558     .read = ibex_spi_host_read,
559     .write = ibex_spi_host_write,
560     /* Ibex default LE */
561     .endianness = DEVICE_LITTLE_ENDIAN,
562 };
563 
564 static Property ibex_spi_properties[] = {
565     DEFINE_PROP_UINT32("num_cs", IbexSPIHostState, num_cs, 1),
566     DEFINE_PROP_END_OF_LIST(),
567 };
568 
569 static const VMStateDescription vmstate_ibex = {
570     .name = TYPE_IBEX_SPI_HOST,
571     .version_id = 1,
572     .minimum_version_id = 1,
573     .fields = (const VMStateField[]) {
574         VMSTATE_UINT32_ARRAY(regs, IbexSPIHostState, IBEX_SPI_HOST_MAX_REGS),
575         VMSTATE_VARRAY_UINT32(config_opts, IbexSPIHostState,
576                               num_cs, 0, vmstate_info_uint32, uint32_t),
577         VMSTATE_FIFO8(rx_fifo, IbexSPIHostState),
578         VMSTATE_FIFO8(tx_fifo, IbexSPIHostState),
579         VMSTATE_TIMER_PTR(fifo_trigger_handle, IbexSPIHostState),
580         VMSTATE_BOOL(init_status, IbexSPIHostState),
581         VMSTATE_END_OF_LIST()
582     }
583 };
584 
585 static void fifo_trigger_update(void *opaque)
586 {
587     IbexSPIHostState *s = opaque;
588     ibex_spi_host_transfer(s);
589 }
590 
591 static void ibex_spi_host_realize(DeviceState *dev, Error **errp)
592 {
593     IbexSPIHostState *s = IBEX_SPI_HOST(dev);
594     int i;
595 
596     s->ssi = ssi_create_bus(dev, "ssi");
597     s->cs_lines = g_new0(qemu_irq, s->num_cs);
598 
599     for (i = 0; i < s->num_cs; ++i) {
600         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->cs_lines[i]);
601     }
602 
603     /* Setup CONFIGOPTS Multi-register */
604     s->config_opts = g_new0(uint32_t, s->num_cs);
605 
606     /* Setup FIFO Interrupt Timer */
607     s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL,
608                                           fifo_trigger_update, s);
609 
610     /* FIFO sizes as per OT Spec */
611     fifo8_create(&s->tx_fifo, IBEX_SPI_HOST_TXFIFO_LEN);
612     fifo8_create(&s->rx_fifo, IBEX_SPI_HOST_RXFIFO_LEN);
613 }
614 
615 static void ibex_spi_host_init(Object *obj)
616 {
617     IbexSPIHostState *s = IBEX_SPI_HOST(obj);
618 
619     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->host_err);
620     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->event);
621 
622     memory_region_init_io(&s->mmio, obj, &ibex_spi_ops, s,
623                           TYPE_IBEX_SPI_HOST, 0x1000);
624     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
625 }
626 
627 static void ibex_spi_host_class_init(ObjectClass *klass, void *data)
628 {
629     DeviceClass *dc = DEVICE_CLASS(klass);
630     dc->realize = ibex_spi_host_realize;
631     dc->reset = ibex_spi_host_reset;
632     dc->vmsd = &vmstate_ibex;
633     device_class_set_props(dc, ibex_spi_properties);
634 }
635 
636 static const TypeInfo ibex_spi_host_info = {
637     .name          = TYPE_IBEX_SPI_HOST,
638     .parent        = TYPE_SYS_BUS_DEVICE,
639     .instance_size = sizeof(IbexSPIHostState),
640     .instance_init = ibex_spi_host_init,
641     .class_init    = ibex_spi_host_class_init,
642 };
643 
644 static void ibex_spi_host_register_types(void)
645 {
646     type_register_static(&ibex_spi_host_info);
647 }
648 
649 type_init(ibex_spi_host_register_types)
650