xref: /openbmc/qemu/hw/net/allwinner_emac.c (revision 8692aa29)
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 #include "qemu/osdep.h"
20 #include "hw/sysbus.h"
21 #include "net/net.h"
22 #include "qemu/fifo8.h"
23 #include "hw/net/allwinner_emac.h"
24 #include "qemu/log.h"
25 #include <zlib.h>
26 
27 static uint8_t padding[60];
28 
29 static void mii_set_link(RTL8201CPState *mii, bool link_ok)
30 {
31     if (link_ok) {
32         mii->bmsr |= MII_BMSR_LINK_ST | MII_BMSR_AN_COMP;
33         mii->anlpar |= MII_ANAR_TXFD | MII_ANAR_10FD | MII_ANAR_10 |
34                        MII_ANAR_CSMACD;
35     } else {
36         mii->bmsr &= ~(MII_BMSR_LINK_ST | MII_BMSR_AN_COMP);
37         mii->anlpar = MII_ANAR_TX;
38     }
39 }
40 
41 static void mii_reset(RTL8201CPState *mii, bool link_ok)
42 {
43     mii->bmcr = MII_BMCR_FD | MII_BMCR_AUTOEN | MII_BMCR_SPEED;
44     mii->bmsr = MII_BMSR_100TX_FD | MII_BMSR_100TX_HD | MII_BMSR_10T_FD |
45                 MII_BMSR_10T_HD | MII_BMSR_MFPS | MII_BMSR_AUTONEG;
46     mii->anar = MII_ANAR_TXFD | MII_ANAR_TX | MII_ANAR_10FD | MII_ANAR_10 |
47                 MII_ANAR_CSMACD;
48     mii->anlpar = MII_ANAR_TX;
49 
50     mii_set_link(mii, link_ok);
51 }
52 
53 static uint16_t RTL8201CP_mdio_read(AwEmacState *s, uint8_t addr, uint8_t reg)
54 {
55     RTL8201CPState *mii = &s->mii;
56     uint16_t ret = 0xffff;
57 
58     if (addr == s->phy_addr) {
59         switch (reg) {
60         case MII_BMCR:
61             return mii->bmcr;
62         case MII_BMSR:
63             return mii->bmsr;
64         case MII_PHYID1:
65             return RTL8201CP_PHYID1;
66         case MII_PHYID2:
67             return RTL8201CP_PHYID2;
68         case MII_ANAR:
69             return mii->anar;
70         case MII_ANLPAR:
71             return mii->anlpar;
72         case MII_ANER:
73         case MII_NSR:
74         case MII_LBREMR:
75         case MII_REC:
76         case MII_SNRDR:
77         case MII_TEST:
78             qemu_log_mask(LOG_UNIMP,
79                           "allwinner_emac: read from unimpl. mii reg 0x%x\n",
80                           reg);
81             return 0;
82         default:
83             qemu_log_mask(LOG_GUEST_ERROR,
84                           "allwinner_emac: read from invalid mii reg 0x%x\n",
85                           reg);
86             return 0;
87         }
88     }
89     return ret;
90 }
91 
92 static void RTL8201CP_mdio_write(AwEmacState *s, uint8_t addr, uint8_t reg,
93                                  uint16_t value)
94 {
95     RTL8201CPState *mii = &s->mii;
96     NetClientState *nc;
97 
98     if (addr == s->phy_addr) {
99         switch (reg) {
100         case MII_BMCR:
101             if (value & MII_BMCR_RESET) {
102                 nc = qemu_get_queue(s->nic);
103                 mii_reset(mii, !nc->link_down);
104             } else {
105                 mii->bmcr = value;
106             }
107             break;
108         case MII_ANAR:
109             mii->anar = value;
110             break;
111         case MII_BMSR:
112         case MII_PHYID1:
113         case MII_PHYID2:
114         case MII_ANLPAR:
115         case MII_ANER:
116             qemu_log_mask(LOG_GUEST_ERROR,
117                           "allwinner_emac: write to read-only mii reg 0x%x\n",
118                           reg);
119             break;
120         case MII_NSR:
121         case MII_LBREMR:
122         case MII_REC:
123         case MII_SNRDR:
124         case MII_TEST:
125             qemu_log_mask(LOG_UNIMP,
126                           "allwinner_emac: write to unimpl. mii reg 0x%x\n",
127                           reg);
128             break;
129         default:
130             qemu_log_mask(LOG_GUEST_ERROR,
131                           "allwinner_emac: write to invalid mii reg 0x%x\n",
132                           reg);
133         }
134     }
135 }
136 
137 static void aw_emac_update_irq(AwEmacState *s)
138 {
139     qemu_set_irq(s->irq, (s->int_sta & s->int_ctl) != 0);
140 }
141 
142 static void aw_emac_tx_reset(AwEmacState *s, int chan)
143 {
144     fifo8_reset(&s->tx_fifo[chan]);
145     s->tx_length[chan] = 0;
146 }
147 
148 static void aw_emac_rx_reset(AwEmacState *s)
149 {
150     fifo8_reset(&s->rx_fifo);
151     s->rx_num_packets = 0;
152     s->rx_packet_size = 0;
153     s->rx_packet_pos = 0;
154 }
155 
156 static void fifo8_push_word(Fifo8 *fifo, uint32_t val)
157 {
158     fifo8_push(fifo, val);
159     fifo8_push(fifo, val >> 8);
160     fifo8_push(fifo, val >> 16);
161     fifo8_push(fifo, val >> 24);
162 }
163 
164 static uint32_t fifo8_pop_word(Fifo8 *fifo)
165 {
166     uint32_t ret;
167 
168     ret = fifo8_pop(fifo);
169     ret |= fifo8_pop(fifo) << 8;
170     ret |= fifo8_pop(fifo) << 16;
171     ret |= fifo8_pop(fifo) << 24;
172 
173     return ret;
174 }
175 
176 static int aw_emac_can_receive(NetClientState *nc)
177 {
178     AwEmacState *s = qemu_get_nic_opaque(nc);
179 
180     /*
181      * To avoid packet drops, allow reception only when there is space
182      * for a full frame: 1522 + 8 (rx headers) + 2 (padding).
183      */
184     return (s->ctl & EMAC_CTL_RX_EN) && (fifo8_num_free(&s->rx_fifo) >= 1532);
185 }
186 
187 static ssize_t aw_emac_receive(NetClientState *nc, const uint8_t *buf,
188                                size_t size)
189 {
190     AwEmacState *s = qemu_get_nic_opaque(nc);
191     Fifo8 *fifo = &s->rx_fifo;
192     size_t padded_size, total_size;
193     uint32_t crc;
194 
195     padded_size = size > 60 ? size : 60;
196     total_size = QEMU_ALIGN_UP(RX_HDR_SIZE + padded_size + CRC_SIZE, 4);
197 
198     if (!(s->ctl & EMAC_CTL_RX_EN) || (fifo8_num_free(fifo) < total_size)) {
199         return -1;
200     }
201 
202     fifo8_push_word(fifo, EMAC_UNDOCUMENTED_MAGIC);
203     fifo8_push_word(fifo, EMAC_RX_HEADER(padded_size + CRC_SIZE,
204                                          EMAC_RX_IO_DATA_STATUS_OK));
205     fifo8_push_all(fifo, buf, size);
206     crc = crc32(~0, buf, size);
207 
208     if (padded_size != size) {
209         fifo8_push_all(fifo, padding, padded_size - size);
210         crc = crc32(crc, padding, padded_size - size);
211     }
212 
213     fifo8_push_word(fifo, crc);
214     fifo8_push_all(fifo, padding, QEMU_ALIGN_UP(padded_size, 4) - padded_size);
215     s->rx_num_packets++;
216 
217     s->int_sta |= EMAC_INT_RX;
218     aw_emac_update_irq(s);
219 
220     return size;
221 }
222 
223 static void aw_emac_reset(DeviceState *dev)
224 {
225     AwEmacState *s = AW_EMAC(dev);
226     NetClientState *nc = qemu_get_queue(s->nic);
227 
228     s->ctl = 0;
229     s->tx_mode = 0;
230     s->int_ctl = 0;
231     s->int_sta = 0;
232     s->tx_channel = 0;
233     s->phy_target = 0;
234 
235     aw_emac_tx_reset(s, 0);
236     aw_emac_tx_reset(s, 1);
237     aw_emac_rx_reset(s);
238 
239     mii_reset(&s->mii, !nc->link_down);
240 }
241 
242 static uint64_t aw_emac_read(void *opaque, hwaddr offset, unsigned size)
243 {
244     AwEmacState *s = opaque;
245     Fifo8 *fifo = &s->rx_fifo;
246     NetClientState *nc;
247     uint64_t ret;
248 
249     switch (offset) {
250     case EMAC_CTL_REG:
251         return s->ctl;
252     case EMAC_TX_MODE_REG:
253         return s->tx_mode;
254     case EMAC_TX_INS_REG:
255         return s->tx_channel;
256     case EMAC_RX_CTL_REG:
257         return s->rx_ctl;
258     case EMAC_RX_IO_DATA_REG:
259         if (!s->rx_num_packets) {
260             qemu_log_mask(LOG_GUEST_ERROR,
261                           "Read IO data register when no packet available");
262             return 0;
263         }
264 
265         ret = fifo8_pop_word(fifo);
266 
267         switch (s->rx_packet_pos) {
268         case 0:     /* Word is magic header */
269             s->rx_packet_pos += 4;
270             break;
271         case 4:     /* Word is rx info header */
272             s->rx_packet_pos += 4;
273             s->rx_packet_size = QEMU_ALIGN_UP(extract32(ret, 0, 16), 4);
274             break;
275         default:    /* Word is packet data */
276             s->rx_packet_pos += 4;
277             s->rx_packet_size -= 4;
278 
279             if (!s->rx_packet_size) {
280                 s->rx_packet_pos = 0;
281                 s->rx_num_packets--;
282                 nc = qemu_get_queue(s->nic);
283                 if (aw_emac_can_receive(nc)) {
284                     qemu_flush_queued_packets(nc);
285                 }
286             }
287         }
288         return ret;
289     case EMAC_RX_FBC_REG:
290         return s->rx_num_packets;
291     case EMAC_INT_CTL_REG:
292         return s->int_ctl;
293     case EMAC_INT_STA_REG:
294         return s->int_sta;
295     case EMAC_MAC_MRDD_REG:
296         return RTL8201CP_mdio_read(s,
297                                    extract32(s->phy_target, PHY_ADDR_SHIFT, 8),
298                                    extract32(s->phy_target, PHY_REG_SHIFT, 8));
299     default:
300         qemu_log_mask(LOG_UNIMP,
301                       "allwinner_emac: read access to unknown register 0x"
302                       TARGET_FMT_plx "\n", offset);
303         ret = 0;
304     }
305 
306     return ret;
307 }
308 
309 static void aw_emac_write(void *opaque, hwaddr offset, uint64_t value,
310                           unsigned size)
311 {
312     AwEmacState *s = opaque;
313     Fifo8 *fifo;
314     NetClientState *nc = qemu_get_queue(s->nic);
315     int chan;
316 
317     switch (offset) {
318     case EMAC_CTL_REG:
319         if (value & EMAC_CTL_RESET) {
320             aw_emac_reset(DEVICE(s));
321             value &= ~EMAC_CTL_RESET;
322         }
323         s->ctl = value;
324         if (aw_emac_can_receive(nc)) {
325             qemu_flush_queued_packets(nc);
326         }
327         break;
328     case EMAC_TX_MODE_REG:
329         s->tx_mode = value;
330         break;
331     case EMAC_TX_CTL0_REG:
332     case EMAC_TX_CTL1_REG:
333         chan = (offset == EMAC_TX_CTL0_REG ? 0 : 1);
334         if ((value & 1) && (s->ctl & EMAC_CTL_TX_EN)) {
335             uint32_t len, ret;
336             const uint8_t *data;
337 
338             fifo = &s->tx_fifo[chan];
339             len = s->tx_length[chan];
340 
341             if (len > fifo8_num_used(fifo)) {
342                 len = fifo8_num_used(fifo);
343                 qemu_log_mask(LOG_GUEST_ERROR,
344                               "allwinner_emac: TX length > fifo data length\n");
345             }
346             if (len > 0) {
347                 data = fifo8_pop_buf(fifo, len, &ret);
348                 qemu_send_packet(nc, data, ret);
349                 aw_emac_tx_reset(s, chan);
350                 /* Raise TX interrupt */
351                 s->int_sta |= EMAC_INT_TX_CHAN(chan);
352                 aw_emac_update_irq(s);
353             }
354         }
355         break;
356     case EMAC_TX_INS_REG:
357         s->tx_channel = value < NUM_TX_FIFOS ? value : 0;
358         break;
359     case EMAC_TX_PL0_REG:
360     case EMAC_TX_PL1_REG:
361         chan = (offset == EMAC_TX_PL0_REG ? 0 : 1);
362         if (value > TX_FIFO_SIZE) {
363             qemu_log_mask(LOG_GUEST_ERROR,
364                           "allwinner_emac: invalid TX frame length %d\n",
365                           (int)value);
366             value = TX_FIFO_SIZE;
367         }
368         s->tx_length[chan] = value;
369         break;
370     case EMAC_TX_IO_DATA_REG:
371         fifo = &s->tx_fifo[s->tx_channel];
372         if (fifo8_num_free(fifo) < 4) {
373             qemu_log_mask(LOG_GUEST_ERROR,
374                           "allwinner_emac: TX data overruns fifo\n");
375             break;
376         }
377         fifo8_push_word(fifo, value);
378         break;
379     case EMAC_RX_CTL_REG:
380         s->rx_ctl = value;
381         break;
382     case EMAC_RX_FBC_REG:
383         if (value == 0) {
384             aw_emac_rx_reset(s);
385         }
386         break;
387     case EMAC_INT_CTL_REG:
388         s->int_ctl = value;
389         aw_emac_update_irq(s);
390         break;
391     case EMAC_INT_STA_REG:
392         s->int_sta &= ~value;
393         aw_emac_update_irq(s);
394         break;
395     case EMAC_MAC_MADR_REG:
396         s->phy_target = value;
397         break;
398     case EMAC_MAC_MWTD_REG:
399         RTL8201CP_mdio_write(s, extract32(s->phy_target, PHY_ADDR_SHIFT, 8),
400                              extract32(s->phy_target, PHY_REG_SHIFT, 8), value);
401         break;
402     default:
403         qemu_log_mask(LOG_UNIMP,
404                       "allwinner_emac: write access to unknown register 0x"
405                       TARGET_FMT_plx "\n", offset);
406     }
407 }
408 
409 static void aw_emac_set_link(NetClientState *nc)
410 {
411     AwEmacState *s = qemu_get_nic_opaque(nc);
412 
413     mii_set_link(&s->mii, !nc->link_down);
414 }
415 
416 static const MemoryRegionOps aw_emac_mem_ops = {
417     .read = aw_emac_read,
418     .write = aw_emac_write,
419     .endianness = DEVICE_NATIVE_ENDIAN,
420     .valid = {
421         .min_access_size = 4,
422         .max_access_size = 4,
423     },
424 };
425 
426 static NetClientInfo net_aw_emac_info = {
427     .type = NET_CLIENT_OPTIONS_KIND_NIC,
428     .size = sizeof(NICState),
429     .can_receive = aw_emac_can_receive,
430     .receive = aw_emac_receive,
431     .link_status_changed = aw_emac_set_link,
432 };
433 
434 static void aw_emac_init(Object *obj)
435 {
436     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
437     AwEmacState *s = AW_EMAC(obj);
438 
439     memory_region_init_io(&s->iomem, OBJECT(s), &aw_emac_mem_ops, s,
440                           "aw_emac", 0x1000);
441     sysbus_init_mmio(sbd, &s->iomem);
442     sysbus_init_irq(sbd, &s->irq);
443 }
444 
445 static void aw_emac_realize(DeviceState *dev, Error **errp)
446 {
447     AwEmacState *s = AW_EMAC(dev);
448 
449     qemu_macaddr_default_if_unset(&s->conf.macaddr);
450     s->nic = qemu_new_nic(&net_aw_emac_info, &s->conf,
451                           object_get_typename(OBJECT(dev)), dev->id, s);
452     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
453 
454     fifo8_create(&s->rx_fifo, RX_FIFO_SIZE);
455     fifo8_create(&s->tx_fifo[0], TX_FIFO_SIZE);
456     fifo8_create(&s->tx_fifo[1], TX_FIFO_SIZE);
457 }
458 
459 static Property aw_emac_properties[] = {
460     DEFINE_NIC_PROPERTIES(AwEmacState, conf),
461     DEFINE_PROP_UINT8("phy-addr", AwEmacState, phy_addr, 0),
462     DEFINE_PROP_END_OF_LIST(),
463 };
464 
465 static const VMStateDescription vmstate_mii = {
466     .name = "rtl8201cp",
467     .version_id = 1,
468     .minimum_version_id = 1,
469     .fields = (VMStateField[]) {
470         VMSTATE_UINT16(bmcr, RTL8201CPState),
471         VMSTATE_UINT16(bmsr, RTL8201CPState),
472         VMSTATE_UINT16(anar, RTL8201CPState),
473         VMSTATE_UINT16(anlpar, RTL8201CPState),
474         VMSTATE_END_OF_LIST()
475     }
476 };
477 
478 static int aw_emac_post_load(void *opaque, int version_id)
479 {
480     AwEmacState *s = opaque;
481 
482     aw_emac_set_link(qemu_get_queue(s->nic));
483 
484     return 0;
485 }
486 
487 static const VMStateDescription vmstate_aw_emac = {
488     .name = "allwinner_emac",
489     .version_id = 1,
490     .minimum_version_id = 1,
491     .post_load = aw_emac_post_load,
492     .fields = (VMStateField[]) {
493         VMSTATE_STRUCT(mii, AwEmacState, 1, vmstate_mii, RTL8201CPState),
494         VMSTATE_UINT32(ctl, AwEmacState),
495         VMSTATE_UINT32(tx_mode, AwEmacState),
496         VMSTATE_UINT32(rx_ctl, AwEmacState),
497         VMSTATE_UINT32(int_ctl, AwEmacState),
498         VMSTATE_UINT32(int_sta, AwEmacState),
499         VMSTATE_UINT32(phy_target, AwEmacState),
500         VMSTATE_FIFO8(rx_fifo, AwEmacState),
501         VMSTATE_UINT32(rx_num_packets, AwEmacState),
502         VMSTATE_UINT32(rx_packet_size, AwEmacState),
503         VMSTATE_UINT32(rx_packet_pos, AwEmacState),
504         VMSTATE_STRUCT_ARRAY(tx_fifo, AwEmacState, NUM_TX_FIFOS, 1,
505                              vmstate_fifo8, Fifo8),
506         VMSTATE_UINT32_ARRAY(tx_length, AwEmacState, NUM_TX_FIFOS),
507         VMSTATE_UINT32(tx_channel, AwEmacState),
508         VMSTATE_END_OF_LIST()
509     }
510 };
511 
512 static void aw_emac_class_init(ObjectClass *klass, void *data)
513 {
514     DeviceClass *dc = DEVICE_CLASS(klass);
515 
516     dc->realize = aw_emac_realize;
517     dc->props = aw_emac_properties;
518     dc->reset = aw_emac_reset;
519     dc->vmsd = &vmstate_aw_emac;
520 }
521 
522 static const TypeInfo aw_emac_info = {
523     .name           = TYPE_AW_EMAC,
524     .parent         = TYPE_SYS_BUS_DEVICE,
525     .instance_size  = sizeof(AwEmacState),
526     .instance_init   = aw_emac_init,
527     .class_init     = aw_emac_class_init,
528 };
529 
530 static void aw_emac_register_types(void)
531 {
532     type_register_static(&aw_emac_info);
533 }
534 
535 type_init(aw_emac_register_types)
536