xref: /openbmc/qemu/hw/net/allwinner_emac.c (revision 59a3a1c0)
1 /*
2  * Emulation of Allwinner EMAC Fast Ethernet controller and
3  * Realtek RTL8201CP PHY
4  *
5  * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
6  *
7  * This model is based on reverse-engineering of Linux kernel driver.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  * GNU General Public License for more details.
17  *
18  */
19 
20 #include "qemu/osdep.h"
21 #include "hw/sysbus.h"
22 #include "migration/vmstate.h"
23 #include "net/net.h"
24 #include "qemu/fifo8.h"
25 #include "hw/irq.h"
26 #include "hw/net/allwinner_emac.h"
27 #include "hw/qdev-properties.h"
28 #include "qemu/log.h"
29 #include "qemu/module.h"
30 #include <zlib.h>
31 
32 static uint8_t padding[60];
33 
34 static void mii_set_link(RTL8201CPState *mii, bool link_ok)
35 {
36     if (link_ok) {
37         mii->bmsr |= MII_BMSR_LINK_ST | MII_BMSR_AN_COMP;
38         mii->anlpar |= MII_ANAR_TXFD | MII_ANAR_10FD | MII_ANAR_10 |
39                        MII_ANAR_CSMACD;
40     } else {
41         mii->bmsr &= ~(MII_BMSR_LINK_ST | MII_BMSR_AN_COMP);
42         mii->anlpar = MII_ANAR_TX;
43     }
44 }
45 
46 static void mii_reset(RTL8201CPState *mii, bool link_ok)
47 {
48     mii->bmcr = MII_BMCR_FD | MII_BMCR_AUTOEN | MII_BMCR_SPEED;
49     mii->bmsr = MII_BMSR_100TX_FD | MII_BMSR_100TX_HD | MII_BMSR_10T_FD |
50                 MII_BMSR_10T_HD | MII_BMSR_MFPS | MII_BMSR_AUTONEG;
51     mii->anar = MII_ANAR_TXFD | MII_ANAR_TX | MII_ANAR_10FD | MII_ANAR_10 |
52                 MII_ANAR_CSMACD;
53     mii->anlpar = MII_ANAR_TX;
54 
55     mii_set_link(mii, link_ok);
56 }
57 
58 static uint16_t RTL8201CP_mdio_read(AwEmacState *s, uint8_t addr, uint8_t reg)
59 {
60     RTL8201CPState *mii = &s->mii;
61     uint16_t ret = 0xffff;
62 
63     if (addr == s->phy_addr) {
64         switch (reg) {
65         case MII_BMCR:
66             return mii->bmcr;
67         case MII_BMSR:
68             return mii->bmsr;
69         case MII_PHYID1:
70             return RTL8201CP_PHYID1;
71         case MII_PHYID2:
72             return RTL8201CP_PHYID2;
73         case MII_ANAR:
74             return mii->anar;
75         case MII_ANLPAR:
76             return mii->anlpar;
77         case MII_ANER:
78         case MII_NSR:
79         case MII_LBREMR:
80         case MII_REC:
81         case MII_SNRDR:
82         case MII_TEST:
83             qemu_log_mask(LOG_UNIMP,
84                           "allwinner_emac: read from unimpl. mii reg 0x%x\n",
85                           reg);
86             return 0;
87         default:
88             qemu_log_mask(LOG_GUEST_ERROR,
89                           "allwinner_emac: read from invalid mii reg 0x%x\n",
90                           reg);
91             return 0;
92         }
93     }
94     return ret;
95 }
96 
97 static void RTL8201CP_mdio_write(AwEmacState *s, uint8_t addr, uint8_t reg,
98                                  uint16_t value)
99 {
100     RTL8201CPState *mii = &s->mii;
101     NetClientState *nc;
102 
103     if (addr == s->phy_addr) {
104         switch (reg) {
105         case MII_BMCR:
106             if (value & MII_BMCR_RESET) {
107                 nc = qemu_get_queue(s->nic);
108                 mii_reset(mii, !nc->link_down);
109             } else {
110                 mii->bmcr = value;
111             }
112             break;
113         case MII_ANAR:
114             mii->anar = value;
115             break;
116         case MII_BMSR:
117         case MII_PHYID1:
118         case MII_PHYID2:
119         case MII_ANLPAR:
120         case MII_ANER:
121             qemu_log_mask(LOG_GUEST_ERROR,
122                           "allwinner_emac: write to read-only mii reg 0x%x\n",
123                           reg);
124             break;
125         case MII_NSR:
126         case MII_LBREMR:
127         case MII_REC:
128         case MII_SNRDR:
129         case MII_TEST:
130             qemu_log_mask(LOG_UNIMP,
131                           "allwinner_emac: write to unimpl. mii reg 0x%x\n",
132                           reg);
133             break;
134         default:
135             qemu_log_mask(LOG_GUEST_ERROR,
136                           "allwinner_emac: write to invalid mii reg 0x%x\n",
137                           reg);
138         }
139     }
140 }
141 
142 static void aw_emac_update_irq(AwEmacState *s)
143 {
144     qemu_set_irq(s->irq, (s->int_sta & s->int_ctl) != 0);
145 }
146 
147 static void aw_emac_tx_reset(AwEmacState *s, int chan)
148 {
149     fifo8_reset(&s->tx_fifo[chan]);
150     s->tx_length[chan] = 0;
151 }
152 
153 static void aw_emac_rx_reset(AwEmacState *s)
154 {
155     fifo8_reset(&s->rx_fifo);
156     s->rx_num_packets = 0;
157     s->rx_packet_size = 0;
158     s->rx_packet_pos = 0;
159 }
160 
161 static void fifo8_push_word(Fifo8 *fifo, uint32_t val)
162 {
163     fifo8_push(fifo, val);
164     fifo8_push(fifo, val >> 8);
165     fifo8_push(fifo, val >> 16);
166     fifo8_push(fifo, val >> 24);
167 }
168 
169 static uint32_t fifo8_pop_word(Fifo8 *fifo)
170 {
171     uint32_t ret;
172 
173     ret = fifo8_pop(fifo);
174     ret |= fifo8_pop(fifo) << 8;
175     ret |= fifo8_pop(fifo) << 16;
176     ret |= fifo8_pop(fifo) << 24;
177 
178     return ret;
179 }
180 
181 static int aw_emac_can_receive(NetClientState *nc)
182 {
183     AwEmacState *s = qemu_get_nic_opaque(nc);
184 
185     /*
186      * To avoid packet drops, allow reception only when there is space
187      * for a full frame: 1522 + 8 (rx headers) + 2 (padding).
188      */
189     return (s->ctl & EMAC_CTL_RX_EN) && (fifo8_num_free(&s->rx_fifo) >= 1532);
190 }
191 
192 static ssize_t aw_emac_receive(NetClientState *nc, const uint8_t *buf,
193                                size_t size)
194 {
195     AwEmacState *s = qemu_get_nic_opaque(nc);
196     Fifo8 *fifo = &s->rx_fifo;
197     size_t padded_size, total_size;
198     uint32_t crc;
199 
200     padded_size = size > 60 ? size : 60;
201     total_size = QEMU_ALIGN_UP(RX_HDR_SIZE + padded_size + CRC_SIZE, 4);
202 
203     if (!(s->ctl & EMAC_CTL_RX_EN) || (fifo8_num_free(fifo) < total_size)) {
204         return -1;
205     }
206 
207     fifo8_push_word(fifo, EMAC_UNDOCUMENTED_MAGIC);
208     fifo8_push_word(fifo, EMAC_RX_HEADER(padded_size + CRC_SIZE,
209                                          EMAC_RX_IO_DATA_STATUS_OK));
210     fifo8_push_all(fifo, buf, size);
211     crc = crc32(~0, buf, size);
212 
213     if (padded_size != size) {
214         fifo8_push_all(fifo, padding, padded_size - size);
215         crc = crc32(crc, padding, padded_size - size);
216     }
217 
218     fifo8_push_word(fifo, crc);
219     fifo8_push_all(fifo, padding, QEMU_ALIGN_UP(padded_size, 4) - padded_size);
220     s->rx_num_packets++;
221 
222     s->int_sta |= EMAC_INT_RX;
223     aw_emac_update_irq(s);
224 
225     return size;
226 }
227 
228 static void aw_emac_reset(DeviceState *dev)
229 {
230     AwEmacState *s = AW_EMAC(dev);
231     NetClientState *nc = qemu_get_queue(s->nic);
232 
233     s->ctl = 0;
234     s->tx_mode = 0;
235     s->int_ctl = 0;
236     s->int_sta = 0;
237     s->tx_channel = 0;
238     s->phy_target = 0;
239 
240     aw_emac_tx_reset(s, 0);
241     aw_emac_tx_reset(s, 1);
242     aw_emac_rx_reset(s);
243 
244     mii_reset(&s->mii, !nc->link_down);
245 }
246 
247 static uint64_t aw_emac_read(void *opaque, hwaddr offset, unsigned size)
248 {
249     AwEmacState *s = opaque;
250     Fifo8 *fifo = &s->rx_fifo;
251     NetClientState *nc;
252     uint64_t ret;
253 
254     switch (offset) {
255     case EMAC_CTL_REG:
256         return s->ctl;
257     case EMAC_TX_MODE_REG:
258         return s->tx_mode;
259     case EMAC_TX_INS_REG:
260         return s->tx_channel;
261     case EMAC_RX_CTL_REG:
262         return s->rx_ctl;
263     case EMAC_RX_IO_DATA_REG:
264         if (!s->rx_num_packets) {
265             qemu_log_mask(LOG_GUEST_ERROR,
266                           "Read IO data register when no packet available");
267             return 0;
268         }
269 
270         ret = fifo8_pop_word(fifo);
271 
272         switch (s->rx_packet_pos) {
273         case 0:     /* Word is magic header */
274             s->rx_packet_pos += 4;
275             break;
276         case 4:     /* Word is rx info header */
277             s->rx_packet_pos += 4;
278             s->rx_packet_size = QEMU_ALIGN_UP(extract32(ret, 0, 16), 4);
279             break;
280         default:    /* Word is packet data */
281             s->rx_packet_pos += 4;
282             s->rx_packet_size -= 4;
283 
284             if (!s->rx_packet_size) {
285                 s->rx_packet_pos = 0;
286                 s->rx_num_packets--;
287                 nc = qemu_get_queue(s->nic);
288                 if (aw_emac_can_receive(nc)) {
289                     qemu_flush_queued_packets(nc);
290                 }
291             }
292         }
293         return ret;
294     case EMAC_RX_FBC_REG:
295         return s->rx_num_packets;
296     case EMAC_INT_CTL_REG:
297         return s->int_ctl;
298     case EMAC_INT_STA_REG:
299         return s->int_sta;
300     case EMAC_MAC_MRDD_REG:
301         return RTL8201CP_mdio_read(s,
302                                    extract32(s->phy_target, PHY_ADDR_SHIFT, 8),
303                                    extract32(s->phy_target, PHY_REG_SHIFT, 8));
304     default:
305         qemu_log_mask(LOG_UNIMP,
306                       "allwinner_emac: read access to unknown register 0x"
307                       TARGET_FMT_plx "\n", offset);
308         ret = 0;
309     }
310 
311     return ret;
312 }
313 
314 static void aw_emac_write(void *opaque, hwaddr offset, uint64_t value,
315                           unsigned size)
316 {
317     AwEmacState *s = opaque;
318     Fifo8 *fifo;
319     NetClientState *nc = qemu_get_queue(s->nic);
320     int chan;
321 
322     switch (offset) {
323     case EMAC_CTL_REG:
324         if (value & EMAC_CTL_RESET) {
325             aw_emac_reset(DEVICE(s));
326             value &= ~EMAC_CTL_RESET;
327         }
328         s->ctl = value;
329         if (aw_emac_can_receive(nc)) {
330             qemu_flush_queued_packets(nc);
331         }
332         break;
333     case EMAC_TX_MODE_REG:
334         s->tx_mode = value;
335         break;
336     case EMAC_TX_CTL0_REG:
337     case EMAC_TX_CTL1_REG:
338         chan = (offset == EMAC_TX_CTL0_REG ? 0 : 1);
339         if ((value & 1) && (s->ctl & EMAC_CTL_TX_EN)) {
340             uint32_t len, ret;
341             const uint8_t *data;
342 
343             fifo = &s->tx_fifo[chan];
344             len = s->tx_length[chan];
345 
346             if (len > fifo8_num_used(fifo)) {
347                 len = fifo8_num_used(fifo);
348                 qemu_log_mask(LOG_GUEST_ERROR,
349                               "allwinner_emac: TX length > fifo data length\n");
350             }
351             if (len > 0) {
352                 data = fifo8_pop_buf(fifo, len, &ret);
353                 qemu_send_packet(nc, data, ret);
354                 aw_emac_tx_reset(s, chan);
355                 /* Raise TX interrupt */
356                 s->int_sta |= EMAC_INT_TX_CHAN(chan);
357                 aw_emac_update_irq(s);
358             }
359         }
360         break;
361     case EMAC_TX_INS_REG:
362         s->tx_channel = value < NUM_TX_FIFOS ? value : 0;
363         break;
364     case EMAC_TX_PL0_REG:
365     case EMAC_TX_PL1_REG:
366         chan = (offset == EMAC_TX_PL0_REG ? 0 : 1);
367         if (value > TX_FIFO_SIZE) {
368             qemu_log_mask(LOG_GUEST_ERROR,
369                           "allwinner_emac: invalid TX frame length %d\n",
370                           (int)value);
371             value = TX_FIFO_SIZE;
372         }
373         s->tx_length[chan] = value;
374         break;
375     case EMAC_TX_IO_DATA_REG:
376         fifo = &s->tx_fifo[s->tx_channel];
377         if (fifo8_num_free(fifo) < 4) {
378             qemu_log_mask(LOG_GUEST_ERROR,
379                           "allwinner_emac: TX data overruns fifo\n");
380             break;
381         }
382         fifo8_push_word(fifo, value);
383         break;
384     case EMAC_RX_CTL_REG:
385         s->rx_ctl = value;
386         break;
387     case EMAC_RX_FBC_REG:
388         if (value == 0) {
389             aw_emac_rx_reset(s);
390         }
391         break;
392     case EMAC_INT_CTL_REG:
393         s->int_ctl = value;
394         aw_emac_update_irq(s);
395         break;
396     case EMAC_INT_STA_REG:
397         s->int_sta &= ~value;
398         aw_emac_update_irq(s);
399         break;
400     case EMAC_MAC_MADR_REG:
401         s->phy_target = value;
402         break;
403     case EMAC_MAC_MWTD_REG:
404         RTL8201CP_mdio_write(s, extract32(s->phy_target, PHY_ADDR_SHIFT, 8),
405                              extract32(s->phy_target, PHY_REG_SHIFT, 8), value);
406         break;
407     default:
408         qemu_log_mask(LOG_UNIMP,
409                       "allwinner_emac: write access to unknown register 0x"
410                       TARGET_FMT_plx "\n", offset);
411     }
412 }
413 
414 static void aw_emac_set_link(NetClientState *nc)
415 {
416     AwEmacState *s = qemu_get_nic_opaque(nc);
417 
418     mii_set_link(&s->mii, !nc->link_down);
419 }
420 
421 static const MemoryRegionOps aw_emac_mem_ops = {
422     .read = aw_emac_read,
423     .write = aw_emac_write,
424     .endianness = DEVICE_NATIVE_ENDIAN,
425     .valid = {
426         .min_access_size = 4,
427         .max_access_size = 4,
428     },
429 };
430 
431 static NetClientInfo net_aw_emac_info = {
432     .type = NET_CLIENT_DRIVER_NIC,
433     .size = sizeof(NICState),
434     .can_receive = aw_emac_can_receive,
435     .receive = aw_emac_receive,
436     .link_status_changed = aw_emac_set_link,
437 };
438 
439 static void aw_emac_init(Object *obj)
440 {
441     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
442     AwEmacState *s = AW_EMAC(obj);
443 
444     memory_region_init_io(&s->iomem, OBJECT(s), &aw_emac_mem_ops, s,
445                           "aw_emac", 0x1000);
446     sysbus_init_mmio(sbd, &s->iomem);
447     sysbus_init_irq(sbd, &s->irq);
448 }
449 
450 static void aw_emac_realize(DeviceState *dev, Error **errp)
451 {
452     AwEmacState *s = AW_EMAC(dev);
453 
454     qemu_macaddr_default_if_unset(&s->conf.macaddr);
455     s->nic = qemu_new_nic(&net_aw_emac_info, &s->conf,
456                           object_get_typename(OBJECT(dev)), dev->id, s);
457     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
458 
459     fifo8_create(&s->rx_fifo, RX_FIFO_SIZE);
460     fifo8_create(&s->tx_fifo[0], TX_FIFO_SIZE);
461     fifo8_create(&s->tx_fifo[1], TX_FIFO_SIZE);
462 }
463 
464 static Property aw_emac_properties[] = {
465     DEFINE_NIC_PROPERTIES(AwEmacState, conf),
466     DEFINE_PROP_UINT8("phy-addr", AwEmacState, phy_addr, 0),
467     DEFINE_PROP_END_OF_LIST(),
468 };
469 
470 static const VMStateDescription vmstate_mii = {
471     .name = "rtl8201cp",
472     .version_id = 1,
473     .minimum_version_id = 1,
474     .fields = (VMStateField[]) {
475         VMSTATE_UINT16(bmcr, RTL8201CPState),
476         VMSTATE_UINT16(bmsr, RTL8201CPState),
477         VMSTATE_UINT16(anar, RTL8201CPState),
478         VMSTATE_UINT16(anlpar, RTL8201CPState),
479         VMSTATE_END_OF_LIST()
480     }
481 };
482 
483 static int aw_emac_post_load(void *opaque, int version_id)
484 {
485     AwEmacState *s = opaque;
486 
487     aw_emac_set_link(qemu_get_queue(s->nic));
488 
489     return 0;
490 }
491 
492 static const VMStateDescription vmstate_aw_emac = {
493     .name = "allwinner_emac",
494     .version_id = 1,
495     .minimum_version_id = 1,
496     .post_load = aw_emac_post_load,
497     .fields = (VMStateField[]) {
498         VMSTATE_STRUCT(mii, AwEmacState, 1, vmstate_mii, RTL8201CPState),
499         VMSTATE_UINT32(ctl, AwEmacState),
500         VMSTATE_UINT32(tx_mode, AwEmacState),
501         VMSTATE_UINT32(rx_ctl, AwEmacState),
502         VMSTATE_UINT32(int_ctl, AwEmacState),
503         VMSTATE_UINT32(int_sta, AwEmacState),
504         VMSTATE_UINT32(phy_target, AwEmacState),
505         VMSTATE_FIFO8(rx_fifo, AwEmacState),
506         VMSTATE_UINT32(rx_num_packets, AwEmacState),
507         VMSTATE_UINT32(rx_packet_size, AwEmacState),
508         VMSTATE_UINT32(rx_packet_pos, AwEmacState),
509         VMSTATE_STRUCT_ARRAY(tx_fifo, AwEmacState, NUM_TX_FIFOS, 1,
510                              vmstate_fifo8, Fifo8),
511         VMSTATE_UINT32_ARRAY(tx_length, AwEmacState, NUM_TX_FIFOS),
512         VMSTATE_UINT32(tx_channel, AwEmacState),
513         VMSTATE_END_OF_LIST()
514     }
515 };
516 
517 static void aw_emac_class_init(ObjectClass *klass, void *data)
518 {
519     DeviceClass *dc = DEVICE_CLASS(klass);
520 
521     dc->realize = aw_emac_realize;
522     dc->props = aw_emac_properties;
523     dc->reset = aw_emac_reset;
524     dc->vmsd = &vmstate_aw_emac;
525 }
526 
527 static const TypeInfo aw_emac_info = {
528     .name           = TYPE_AW_EMAC,
529     .parent         = TYPE_SYS_BUS_DEVICE,
530     .instance_size  = sizeof(AwEmacState),
531     .instance_init   = aw_emac_init,
532     .class_init     = aw_emac_class_init,
533 };
534 
535 static void aw_emac_register_types(void)
536 {
537     type_register_static(&aw_emac_info);
538 }
539 
540 type_init(aw_emac_register_types)
541