xref: /openbmc/qemu/hw/net/allwinner_emac.c (revision 77a8257e)
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 "hw/sysbus.h"
20 #include "net/net.h"
21 #include "qemu/fifo8.h"
22 #include "hw/net/allwinner_emac.h"
23 #include <zlib.h>
24 
25 static uint8_t padding[60];
26 
27 static void mii_set_link(RTL8201CPState *mii, bool link_ok)
28 {
29     if (link_ok) {
30         mii->bmsr |= MII_BMSR_LINK_ST | MII_BMSR_AN_COMP;
31         mii->anlpar |= MII_ANAR_TXFD | MII_ANAR_10FD | MII_ANAR_10 |
32                        MII_ANAR_CSMACD;
33     } else {
34         mii->bmsr &= ~(MII_BMSR_LINK_ST | MII_BMSR_AN_COMP);
35         mii->anlpar = MII_ANAR_TX;
36     }
37 }
38 
39 static void mii_reset(RTL8201CPState *mii, bool link_ok)
40 {
41     mii->bmcr = MII_BMCR_FD | MII_BMCR_AUTOEN | MII_BMCR_SPEED;
42     mii->bmsr = MII_BMSR_100TX_FD | MII_BMSR_100TX_HD | MII_BMSR_10T_FD |
43                 MII_BMSR_10T_HD | MII_BMSR_MFPS | MII_BMSR_AUTONEG;
44     mii->anar = MII_ANAR_TXFD | MII_ANAR_TX | MII_ANAR_10FD | MII_ANAR_10 |
45                 MII_ANAR_CSMACD;
46     mii->anlpar = MII_ANAR_TX;
47 
48     mii_set_link(mii, link_ok);
49 }
50 
51 static uint16_t RTL8201CP_mdio_read(AwEmacState *s, uint8_t addr, uint8_t reg)
52 {
53     RTL8201CPState *mii = &s->mii;
54     uint16_t ret = 0xffff;
55 
56     if (addr == s->phy_addr) {
57         switch (reg) {
58         case MII_BMCR:
59             return mii->bmcr;
60         case MII_BMSR:
61             return mii->bmsr;
62         case MII_PHYID1:
63             return RTL8201CP_PHYID1;
64         case MII_PHYID2:
65             return RTL8201CP_PHYID2;
66         case MII_ANAR:
67             return mii->anar;
68         case MII_ANLPAR:
69             return mii->anlpar;
70         case MII_ANER:
71         case MII_NSR:
72         case MII_LBREMR:
73         case MII_REC:
74         case MII_SNRDR:
75         case MII_TEST:
76             qemu_log_mask(LOG_UNIMP,
77                           "allwinner_emac: read from unimpl. mii reg 0x%x\n",
78                           reg);
79             return 0;
80         default:
81             qemu_log_mask(LOG_GUEST_ERROR,
82                           "allwinner_emac: read from invalid mii reg 0x%x\n",
83                           reg);
84             return 0;
85         }
86     }
87     return ret;
88 }
89 
90 static void RTL8201CP_mdio_write(AwEmacState *s, uint8_t addr, uint8_t reg,
91                                  uint16_t value)
92 {
93     RTL8201CPState *mii = &s->mii;
94     NetClientState *nc;
95 
96     if (addr == s->phy_addr) {
97         switch (reg) {
98         case MII_BMCR:
99             if (value & MII_BMCR_RESET) {
100                 nc = qemu_get_queue(s->nic);
101                 mii_reset(mii, !nc->link_down);
102             } else {
103                 mii->bmcr = value;
104             }
105             break;
106         case MII_ANAR:
107             mii->anar = value;
108             break;
109         case MII_BMSR:
110         case MII_PHYID1:
111         case MII_PHYID2:
112         case MII_ANLPAR:
113         case MII_ANER:
114             qemu_log_mask(LOG_GUEST_ERROR,
115                           "allwinner_emac: write to read-only mii reg 0x%x\n",
116                           reg);
117             break;
118         case MII_NSR:
119         case MII_LBREMR:
120         case MII_REC:
121         case MII_SNRDR:
122         case MII_TEST:
123             qemu_log_mask(LOG_UNIMP,
124                           "allwinner_emac: write to unimpl. mii reg 0x%x\n",
125                           reg);
126             break;
127         default:
128             qemu_log_mask(LOG_GUEST_ERROR,
129                           "allwinner_emac: write to invalid mii reg 0x%x\n",
130                           reg);
131         }
132     }
133 }
134 
135 static void aw_emac_update_irq(AwEmacState *s)
136 {
137     qemu_set_irq(s->irq, (s->int_sta & s->int_ctl) != 0);
138 }
139 
140 static void aw_emac_tx_reset(AwEmacState *s, int chan)
141 {
142     fifo8_reset(&s->tx_fifo[chan]);
143     s->tx_length[chan] = 0;
144 }
145 
146 static void aw_emac_rx_reset(AwEmacState *s)
147 {
148     fifo8_reset(&s->rx_fifo);
149     s->rx_num_packets = 0;
150     s->rx_packet_size = 0;
151     s->rx_packet_pos = 0;
152 }
153 
154 static void fifo8_push_word(Fifo8 *fifo, uint32_t val)
155 {
156     fifo8_push(fifo, val);
157     fifo8_push(fifo, val >> 8);
158     fifo8_push(fifo, val >> 16);
159     fifo8_push(fifo, val >> 24);
160 }
161 
162 static uint32_t fifo8_pop_word(Fifo8 *fifo)
163 {
164     uint32_t ret;
165 
166     ret = fifo8_pop(fifo);
167     ret |= fifo8_pop(fifo) << 8;
168     ret |= fifo8_pop(fifo) << 16;
169     ret |= fifo8_pop(fifo) << 24;
170 
171     return ret;
172 }
173 
174 static int aw_emac_can_receive(NetClientState *nc)
175 {
176     AwEmacState *s = qemu_get_nic_opaque(nc);
177 
178     /*
179      * To avoid packet drops, allow reception only when there is space
180      * for a full frame: 1522 + 8 (rx headers) + 2 (padding).
181      */
182     return (s->ctl & EMAC_CTL_RX_EN) && (fifo8_num_free(&s->rx_fifo) >= 1532);
183 }
184 
185 static ssize_t aw_emac_receive(NetClientState *nc, const uint8_t *buf,
186                                size_t size)
187 {
188     AwEmacState *s = qemu_get_nic_opaque(nc);
189     Fifo8 *fifo = &s->rx_fifo;
190     size_t padded_size, total_size;
191     uint32_t crc;
192 
193     padded_size = size > 60 ? size : 60;
194     total_size = QEMU_ALIGN_UP(RX_HDR_SIZE + padded_size + CRC_SIZE, 4);
195 
196     if (!(s->ctl & EMAC_CTL_RX_EN) || (fifo8_num_free(fifo) < total_size)) {
197         return -1;
198     }
199 
200     fifo8_push_word(fifo, EMAC_UNDOCUMENTED_MAGIC);
201     fifo8_push_word(fifo, EMAC_RX_HEADER(padded_size + CRC_SIZE,
202                                          EMAC_RX_IO_DATA_STATUS_OK));
203     fifo8_push_all(fifo, buf, size);
204     crc = crc32(~0, buf, size);
205 
206     if (padded_size != size) {
207         fifo8_push_all(fifo, padding, padded_size - size);
208         crc = crc32(crc, padding, padded_size - size);
209     }
210 
211     fifo8_push_word(fifo, crc);
212     fifo8_push_all(fifo, padding, QEMU_ALIGN_UP(padded_size, 4) - padded_size);
213     s->rx_num_packets++;
214 
215     s->int_sta |= EMAC_INT_RX;
216     aw_emac_update_irq(s);
217 
218     return size;
219 }
220 
221 static void aw_emac_reset(DeviceState *dev)
222 {
223     AwEmacState *s = AW_EMAC(dev);
224     NetClientState *nc = qemu_get_queue(s->nic);
225 
226     s->ctl = 0;
227     s->tx_mode = 0;
228     s->int_ctl = 0;
229     s->int_sta = 0;
230     s->tx_channel = 0;
231     s->phy_target = 0;
232 
233     aw_emac_tx_reset(s, 0);
234     aw_emac_tx_reset(s, 1);
235     aw_emac_rx_reset(s);
236 
237     mii_reset(&s->mii, !nc->link_down);
238 }
239 
240 static uint64_t aw_emac_read(void *opaque, hwaddr offset, unsigned size)
241 {
242     AwEmacState *s = opaque;
243     Fifo8 *fifo = &s->rx_fifo;
244     NetClientState *nc;
245     uint64_t ret;
246 
247     switch (offset) {
248     case EMAC_CTL_REG:
249         return s->ctl;
250     case EMAC_TX_MODE_REG:
251         return s->tx_mode;
252     case EMAC_TX_INS_REG:
253         return s->tx_channel;
254     case EMAC_RX_CTL_REG:
255         return s->rx_ctl;
256     case EMAC_RX_IO_DATA_REG:
257         if (!s->rx_num_packets) {
258             qemu_log_mask(LOG_GUEST_ERROR,
259                           "Read IO data register when no packet available");
260             return 0;
261         }
262 
263         ret = fifo8_pop_word(fifo);
264 
265         switch (s->rx_packet_pos) {
266         case 0:     /* Word is magic header */
267             s->rx_packet_pos += 4;
268             break;
269         case 4:     /* Word is rx info header */
270             s->rx_packet_pos += 4;
271             s->rx_packet_size = QEMU_ALIGN_UP(extract32(ret, 0, 16), 4);
272             break;
273         default:    /* Word is packet data */
274             s->rx_packet_pos += 4;
275             s->rx_packet_size -= 4;
276 
277             if (!s->rx_packet_size) {
278                 s->rx_packet_pos = 0;
279                 s->rx_num_packets--;
280                 nc = qemu_get_queue(s->nic);
281                 if (aw_emac_can_receive(nc)) {
282                     qemu_flush_queued_packets(nc);
283                 }
284             }
285         }
286         return ret;
287     case EMAC_RX_FBC_REG:
288         return s->rx_num_packets;
289     case EMAC_INT_CTL_REG:
290         return s->int_ctl;
291     case EMAC_INT_STA_REG:
292         return s->int_sta;
293     case EMAC_MAC_MRDD_REG:
294         return RTL8201CP_mdio_read(s,
295                                    extract32(s->phy_target, PHY_ADDR_SHIFT, 8),
296                                    extract32(s->phy_target, PHY_REG_SHIFT, 8));
297     default:
298         qemu_log_mask(LOG_UNIMP,
299                       "allwinner_emac: read access to unknown register 0x"
300                       TARGET_FMT_plx "\n", offset);
301         ret = 0;
302     }
303 
304     return ret;
305 }
306 
307 static void aw_emac_write(void *opaque, hwaddr offset, uint64_t value,
308                           unsigned size)
309 {
310     AwEmacState *s = opaque;
311     Fifo8 *fifo;
312     NetClientState *nc = qemu_get_queue(s->nic);
313     int chan;
314 
315     switch (offset) {
316     case EMAC_CTL_REG:
317         if (value & EMAC_CTL_RESET) {
318             aw_emac_reset(DEVICE(s));
319             value &= ~EMAC_CTL_RESET;
320         }
321         s->ctl = value;
322         if (aw_emac_can_receive(nc)) {
323             qemu_flush_queued_packets(nc);
324         }
325         break;
326     case EMAC_TX_MODE_REG:
327         s->tx_mode = value;
328         break;
329     case EMAC_TX_CTL0_REG:
330     case EMAC_TX_CTL1_REG:
331         chan = (offset == EMAC_TX_CTL0_REG ? 0 : 1);
332         if ((value & 1) && (s->ctl & EMAC_CTL_TX_EN)) {
333             uint32_t len, ret;
334             const uint8_t *data;
335 
336             fifo = &s->tx_fifo[chan];
337             len = s->tx_length[chan];
338 
339             if (len > fifo8_num_used(fifo)) {
340                 len = fifo8_num_used(fifo);
341                 qemu_log_mask(LOG_GUEST_ERROR,
342                               "allwinner_emac: TX length > fifo data length\n");
343             }
344             if (len > 0) {
345                 data = fifo8_pop_buf(fifo, len, &ret);
346                 qemu_send_packet(nc, data, ret);
347                 aw_emac_tx_reset(s, chan);
348                 /* Raise TX interrupt */
349                 s->int_sta |= EMAC_INT_TX_CHAN(chan);
350                 aw_emac_update_irq(s);
351             }
352         }
353         break;
354     case EMAC_TX_INS_REG:
355         s->tx_channel = value < NUM_TX_FIFOS ? value : 0;
356         break;
357     case EMAC_TX_PL0_REG:
358     case EMAC_TX_PL1_REG:
359         chan = (offset == EMAC_TX_PL0_REG ? 0 : 1);
360         if (value > TX_FIFO_SIZE) {
361             qemu_log_mask(LOG_GUEST_ERROR,
362                           "allwinner_emac: invalid TX frame length %d\n",
363                           (int)value);
364             value = TX_FIFO_SIZE;
365         }
366         s->tx_length[chan] = value;
367         break;
368     case EMAC_TX_IO_DATA_REG:
369         fifo = &s->tx_fifo[s->tx_channel];
370         if (fifo8_num_free(fifo) < 4) {
371             qemu_log_mask(LOG_GUEST_ERROR,
372                           "allwinner_emac: TX data overruns fifo\n");
373             break;
374         }
375         fifo8_push_word(fifo, value);
376         break;
377     case EMAC_RX_CTL_REG:
378         s->rx_ctl = value;
379         break;
380     case EMAC_RX_FBC_REG:
381         if (value == 0) {
382             aw_emac_rx_reset(s);
383         }
384         break;
385     case EMAC_INT_CTL_REG:
386         s->int_ctl = value;
387         aw_emac_update_irq(s);
388         break;
389     case EMAC_INT_STA_REG:
390         s->int_sta &= ~value;
391         aw_emac_update_irq(s);
392         break;
393     case EMAC_MAC_MADR_REG:
394         s->phy_target = value;
395         break;
396     case EMAC_MAC_MWTD_REG:
397         RTL8201CP_mdio_write(s, extract32(s->phy_target, PHY_ADDR_SHIFT, 8),
398                              extract32(s->phy_target, PHY_REG_SHIFT, 8), value);
399         break;
400     default:
401         qemu_log_mask(LOG_UNIMP,
402                       "allwinner_emac: write access to unknown register 0x"
403                       TARGET_FMT_plx "\n", offset);
404     }
405 }
406 
407 static void aw_emac_set_link(NetClientState *nc)
408 {
409     AwEmacState *s = qemu_get_nic_opaque(nc);
410 
411     mii_set_link(&s->mii, !nc->link_down);
412 }
413 
414 static const MemoryRegionOps aw_emac_mem_ops = {
415     .read = aw_emac_read,
416     .write = aw_emac_write,
417     .endianness = DEVICE_NATIVE_ENDIAN,
418     .valid = {
419         .min_access_size = 4,
420         .max_access_size = 4,
421     },
422 };
423 
424 static NetClientInfo net_aw_emac_info = {
425     .type = NET_CLIENT_OPTIONS_KIND_NIC,
426     .size = sizeof(NICState),
427     .can_receive = aw_emac_can_receive,
428     .receive = aw_emac_receive,
429     .link_status_changed = aw_emac_set_link,
430 };
431 
432 static void aw_emac_init(Object *obj)
433 {
434     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
435     AwEmacState *s = AW_EMAC(obj);
436 
437     memory_region_init_io(&s->iomem, OBJECT(s), &aw_emac_mem_ops, s,
438                           "aw_emac", 0x1000);
439     sysbus_init_mmio(sbd, &s->iomem);
440     sysbus_init_irq(sbd, &s->irq);
441 }
442 
443 static void aw_emac_realize(DeviceState *dev, Error **errp)
444 {
445     AwEmacState *s = AW_EMAC(dev);
446 
447     qemu_macaddr_default_if_unset(&s->conf.macaddr);
448     s->nic = qemu_new_nic(&net_aw_emac_info, &s->conf,
449                           object_get_typename(OBJECT(dev)), dev->id, s);
450     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
451 
452     fifo8_create(&s->rx_fifo, RX_FIFO_SIZE);
453     fifo8_create(&s->tx_fifo[0], TX_FIFO_SIZE);
454     fifo8_create(&s->tx_fifo[1], TX_FIFO_SIZE);
455 }
456 
457 static Property aw_emac_properties[] = {
458     DEFINE_NIC_PROPERTIES(AwEmacState, conf),
459     DEFINE_PROP_UINT8("phy-addr", AwEmacState, phy_addr, 0),
460     DEFINE_PROP_END_OF_LIST(),
461 };
462 
463 static const VMStateDescription vmstate_mii = {
464     .name = "rtl8201cp",
465     .version_id = 1,
466     .minimum_version_id = 1,
467     .fields = (VMStateField[]) {
468         VMSTATE_UINT16(bmcr, RTL8201CPState),
469         VMSTATE_UINT16(bmsr, RTL8201CPState),
470         VMSTATE_UINT16(anar, RTL8201CPState),
471         VMSTATE_UINT16(anlpar, RTL8201CPState),
472         VMSTATE_END_OF_LIST()
473     }
474 };
475 
476 static int aw_emac_post_load(void *opaque, int version_id)
477 {
478     AwEmacState *s = opaque;
479 
480     aw_emac_set_link(qemu_get_queue(s->nic));
481 
482     return 0;
483 }
484 
485 static const VMStateDescription vmstate_aw_emac = {
486     .name = "allwinner_emac",
487     .version_id = 1,
488     .minimum_version_id = 1,
489     .post_load = aw_emac_post_load,
490     .fields = (VMStateField[]) {
491         VMSTATE_STRUCT(mii, AwEmacState, 1, vmstate_mii, RTL8201CPState),
492         VMSTATE_UINT32(ctl, AwEmacState),
493         VMSTATE_UINT32(tx_mode, AwEmacState),
494         VMSTATE_UINT32(rx_ctl, AwEmacState),
495         VMSTATE_UINT32(int_ctl, AwEmacState),
496         VMSTATE_UINT32(int_sta, AwEmacState),
497         VMSTATE_UINT32(phy_target, AwEmacState),
498         VMSTATE_FIFO8(rx_fifo, AwEmacState),
499         VMSTATE_UINT32(rx_num_packets, AwEmacState),
500         VMSTATE_UINT32(rx_packet_size, AwEmacState),
501         VMSTATE_UINT32(rx_packet_pos, AwEmacState),
502         VMSTATE_STRUCT_ARRAY(tx_fifo, AwEmacState, NUM_TX_FIFOS, 1,
503                              vmstate_fifo8, Fifo8),
504         VMSTATE_UINT32_ARRAY(tx_length, AwEmacState, NUM_TX_FIFOS),
505         VMSTATE_UINT32(tx_channel, AwEmacState),
506         VMSTATE_END_OF_LIST()
507     }
508 };
509 
510 static void aw_emac_class_init(ObjectClass *klass, void *data)
511 {
512     DeviceClass *dc = DEVICE_CLASS(klass);
513 
514     dc->realize = aw_emac_realize;
515     dc->props = aw_emac_properties;
516     dc->reset = aw_emac_reset;
517     dc->vmsd = &vmstate_aw_emac;
518 }
519 
520 static const TypeInfo aw_emac_info = {
521     .name           = TYPE_AW_EMAC,
522     .parent         = TYPE_SYS_BUS_DEVICE,
523     .instance_size  = sizeof(AwEmacState),
524     .instance_init   = aw_emac_init,
525     .class_init     = aw_emac_class_init,
526 };
527 
528 static void aw_emac_register_types(void)
529 {
530     type_register_static(&aw_emac_info);
531 }
532 
533 type_init(aw_emac_register_types)
534