Merge branches 'arm/rockchip', 'arm/exynos', 'arm/smmu', 'x86/vt-d', 'x86/amd', ...
[sfrench/cifs-2.6.git] / drivers / net / ethernet / qualcomm / qca_spi.c
1 /*
2  *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
3  *   Copyright (c) 2014, I2SE GmbH
4  *
5  *   Permission to use, copy, modify, and/or distribute this software
6  *   for any purpose with or without fee is hereby granted, provided
7  *   that the above copyright notice and this permission notice appear
8  *   in all copies.
9  *
10  *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
11  *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
12  *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
13  *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
14  *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
15  *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
16  *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
17  *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19
20 /*   This module implements the Qualcomm Atheros SPI protocol for
21  *   kernel-based SPI device; it is essentially an Ethernet-to-SPI
22  *   serial converter;
23  */
24
25 #include <linux/errno.h>
26 #include <linux/etherdevice.h>
27 #include <linux/if_arp.h>
28 #include <linux/if_ether.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/jiffies.h>
32 #include <linux/kernel.h>
33 #include <linux/kthread.h>
34 #include <linux/module.h>
35 #include <linux/moduleparam.h>
36 #include <linux/netdevice.h>
37 #include <linux/of.h>
38 #include <linux/of_device.h>
39 #include <linux/of_net.h>
40 #include <linux/sched.h>
41 #include <linux/skbuff.h>
42 #include <linux/spi/spi.h>
43 #include <linux/types.h>
44
45 #include "qca_7k.h"
46 #include "qca_debug.h"
47 #include "qca_framing.h"
48 #include "qca_spi.h"
49
50 #define MAX_DMA_BURST_LEN 5000
51
52 /*   Modules parameters     */
53 #define QCASPI_CLK_SPEED_MIN 1000000
54 #define QCASPI_CLK_SPEED_MAX 16000000
55 #define QCASPI_CLK_SPEED     8000000
56 static int qcaspi_clkspeed;
57 module_param(qcaspi_clkspeed, int, 0);
58 MODULE_PARM_DESC(qcaspi_clkspeed, "SPI bus clock speed (Hz). Use 1000000-16000000.");
59
60 #define QCASPI_BURST_LEN_MIN 1
61 #define QCASPI_BURST_LEN_MAX MAX_DMA_BURST_LEN
62 static int qcaspi_burst_len = MAX_DMA_BURST_LEN;
63 module_param(qcaspi_burst_len, int, 0);
64 MODULE_PARM_DESC(qcaspi_burst_len, "Number of data bytes per burst. Use 1-5000.");
65
66 #define QCASPI_PLUGGABLE_MIN 0
67 #define QCASPI_PLUGGABLE_MAX 1
68 static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
69 module_param(qcaspi_pluggable, int, 0);
70 MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
71
72 #define QCASPI_MTU QCAFRM_ETHMAXMTU
73 #define QCASPI_TX_TIMEOUT (1 * HZ)
74 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
75
76 static void
77 start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
78 {
79         *intr_cause = 0;
80
81         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
82         qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
83         netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
84 }
85
86 static void
87 end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
88 {
89         u16 intr_enable = (SPI_INT_CPU_ON |
90                            SPI_INT_PKT_AVLBL |
91                            SPI_INT_RDBUF_ERR |
92                            SPI_INT_WRBUF_ERR);
93
94         qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
95         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable);
96         netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
97 }
98
99 static u32
100 qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
101 {
102         __be16 cmd;
103         struct spi_message *msg = &qca->spi_msg2;
104         struct spi_transfer *transfer = &qca->spi_xfer2[0];
105         int ret;
106
107         cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
108         transfer->tx_buf = &cmd;
109         transfer->rx_buf = NULL;
110         transfer->len = QCASPI_CMD_LEN;
111         transfer = &qca->spi_xfer2[1];
112         transfer->tx_buf = src;
113         transfer->rx_buf = NULL;
114         transfer->len = len;
115
116         ret = spi_sync(qca->spi_dev, msg);
117
118         if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
119                 qcaspi_spi_error(qca);
120                 return 0;
121         }
122
123         return len;
124 }
125
126 static u32
127 qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
128 {
129         struct spi_message *msg = &qca->spi_msg1;
130         struct spi_transfer *transfer = &qca->spi_xfer1;
131         int ret;
132
133         transfer->tx_buf = src;
134         transfer->rx_buf = NULL;
135         transfer->len = len;
136
137         ret = spi_sync(qca->spi_dev, msg);
138
139         if (ret || (msg->actual_length != len)) {
140                 qcaspi_spi_error(qca);
141                 return 0;
142         }
143
144         return len;
145 }
146
147 static u32
148 qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
149 {
150         struct spi_message *msg = &qca->spi_msg2;
151         __be16 cmd;
152         struct spi_transfer *transfer = &qca->spi_xfer2[0];
153         int ret;
154
155         cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
156         transfer->tx_buf = &cmd;
157         transfer->rx_buf = NULL;
158         transfer->len = QCASPI_CMD_LEN;
159         transfer = &qca->spi_xfer2[1];
160         transfer->tx_buf = NULL;
161         transfer->rx_buf = dst;
162         transfer->len = len;
163
164         ret = spi_sync(qca->spi_dev, msg);
165
166         if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
167                 qcaspi_spi_error(qca);
168                 return 0;
169         }
170
171         return len;
172 }
173
174 static u32
175 qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
176 {
177         struct spi_message *msg = &qca->spi_msg1;
178         struct spi_transfer *transfer = &qca->spi_xfer1;
179         int ret;
180
181         transfer->tx_buf = NULL;
182         transfer->rx_buf = dst;
183         transfer->len = len;
184
185         ret = spi_sync(qca->spi_dev, msg);
186
187         if (ret || (msg->actual_length != len)) {
188                 qcaspi_spi_error(qca);
189                 return 0;
190         }
191
192         return len;
193 }
194
195 static int
196 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
197 {
198         u32 count;
199         u32 written;
200         u32 offset;
201         u32 len;
202
203         len = skb->len;
204
205         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len);
206         if (qca->legacy_mode)
207                 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
208
209         offset = 0;
210         while (len) {
211                 count = len;
212                 if (count > qca->burst_len)
213                         count = qca->burst_len;
214
215                 if (qca->legacy_mode) {
216                         written = qcaspi_write_legacy(qca,
217                                                       skb->data + offset,
218                                                       count);
219                 } else {
220                         written = qcaspi_write_burst(qca,
221                                                      skb->data + offset,
222                                                      count);
223                 }
224
225                 if (written != count)
226                         return -1;
227
228                 offset += count;
229                 len -= count;
230         }
231
232         return 0;
233 }
234
235 static int
236 qcaspi_transmit(struct qcaspi *qca)
237 {
238         struct net_device_stats *n_stats = &qca->net_dev->stats;
239         u16 available = 0;
240         u32 pkt_len;
241         u16 new_head;
242         u16 packets = 0;
243
244         if (qca->txr.skb[qca->txr.head] == NULL)
245                 return 0;
246
247         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
248
249         while (qca->txr.skb[qca->txr.head]) {
250                 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
251
252                 if (available < pkt_len) {
253                         if (packets == 0)
254                                 qca->stats.write_buf_miss++;
255                         break;
256                 }
257
258                 if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
259                         qca->stats.write_err++;
260                         return -1;
261                 }
262
263                 packets++;
264                 n_stats->tx_packets++;
265                 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
266                 available -= pkt_len;
267
268                 /* remove the skb from the queue */
269                 /* XXX After inconsistent lock states netif_tx_lock()
270                  * has been replaced by netif_tx_lock_bh() and so on.
271                  */
272                 netif_tx_lock_bh(qca->net_dev);
273                 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
274                 qca->txr.skb[qca->txr.head] = NULL;
275                 qca->txr.size -= pkt_len;
276                 new_head = qca->txr.head + 1;
277                 if (new_head >= qca->txr.count)
278                         new_head = 0;
279                 qca->txr.head = new_head;
280                 if (netif_queue_stopped(qca->net_dev))
281                         netif_wake_queue(qca->net_dev);
282                 netif_tx_unlock_bh(qca->net_dev);
283         }
284
285         return 0;
286 }
287
288 static int
289 qcaspi_receive(struct qcaspi *qca)
290 {
291         struct net_device *net_dev = qca->net_dev;
292         struct net_device_stats *n_stats = &net_dev->stats;
293         u16 available = 0;
294         u32 bytes_read;
295         u8 *cp;
296
297         /* Allocate rx SKB if we don't have one available. */
298         if (!qca->rx_skb) {
299                 qca->rx_skb = netdev_alloc_skb(net_dev,
300                                                net_dev->mtu + VLAN_ETH_HLEN);
301                 if (!qca->rx_skb) {
302                         netdev_dbg(net_dev, "out of RX resources\n");
303                         qca->stats.out_of_mem++;
304                         return -1;
305                 }
306         }
307
308         /* Read the packet size. */
309         qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
310         netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
311                    available);
312
313         if (available == 0) {
314                 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
315                 return -1;
316         }
317
318         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available);
319
320         if (qca->legacy_mode)
321                 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
322
323         while (available) {
324                 u32 count = available;
325
326                 if (count > qca->burst_len)
327                         count = qca->burst_len;
328
329                 if (qca->legacy_mode) {
330                         bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
331                                                         count);
332                 } else {
333                         bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
334                                                        count);
335                 }
336
337                 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
338                            available, bytes_read);
339
340                 if (bytes_read) {
341                         available -= bytes_read;
342                 } else {
343                         qca->stats.read_err++;
344                         return -1;
345                 }
346
347                 cp = qca->rx_buffer;
348
349                 while ((bytes_read--) && (qca->rx_skb)) {
350                         s32 retcode;
351
352                         retcode = qcafrm_fsm_decode(&qca->frm_handle,
353                                                     qca->rx_skb->data,
354                                                     skb_tailroom(qca->rx_skb),
355                                                     *cp);
356                         cp++;
357                         switch (retcode) {
358                         case QCAFRM_GATHER:
359                         case QCAFRM_NOHEAD:
360                                 break;
361                         case QCAFRM_NOTAIL:
362                                 netdev_dbg(net_dev, "no RX tail\n");
363                                 n_stats->rx_errors++;
364                                 n_stats->rx_dropped++;
365                                 break;
366                         case QCAFRM_INVLEN:
367                                 netdev_dbg(net_dev, "invalid RX length\n");
368                                 n_stats->rx_errors++;
369                                 n_stats->rx_dropped++;
370                                 break;
371                         default:
372                                 qca->rx_skb->dev = qca->net_dev;
373                                 n_stats->rx_packets++;
374                                 n_stats->rx_bytes += retcode;
375                                 skb_put(qca->rx_skb, retcode);
376                                 qca->rx_skb->protocol = eth_type_trans(
377                                         qca->rx_skb, qca->rx_skb->dev);
378                                 qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
379                                 netif_rx_ni(qca->rx_skb);
380                                 qca->rx_skb = netdev_alloc_skb(net_dev,
381                                         net_dev->mtu + VLAN_ETH_HLEN);
382                                 if (!qca->rx_skb) {
383                                         netdev_dbg(net_dev, "out of RX resources\n");
384                                         n_stats->rx_errors++;
385                                         qca->stats.out_of_mem++;
386                                         break;
387                                 }
388                         }
389                 }
390         }
391
392         return 0;
393 }
394
395 /*   Check that tx ring stores only so much bytes
396  *   that fit into the internal QCA buffer.
397  */
398
399 static int
400 qcaspi_tx_ring_has_space(struct tx_ring *txr)
401 {
402         if (txr->skb[txr->tail])
403                 return 0;
404
405         return (txr->size + QCAFRM_ETHMAXLEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
406 }
407
408 /*   Flush the tx ring. This function is only safe to
409  *   call from the qcaspi_spi_thread.
410  */
411
412 static void
413 qcaspi_flush_tx_ring(struct qcaspi *qca)
414 {
415         int i;
416
417         /* XXX After inconsistent lock states netif_tx_lock()
418          * has been replaced by netif_tx_lock_bh() and so on.
419          */
420         netif_tx_lock_bh(qca->net_dev);
421         for (i = 0; i < TX_RING_MAX_LEN; i++) {
422                 if (qca->txr.skb[i]) {
423                         dev_kfree_skb(qca->txr.skb[i]);
424                         qca->txr.skb[i] = NULL;
425                         qca->net_dev->stats.tx_dropped++;
426                 }
427         }
428         qca->txr.tail = 0;
429         qca->txr.head = 0;
430         qca->txr.size = 0;
431         netif_tx_unlock_bh(qca->net_dev);
432 }
433
434 static void
435 qcaspi_qca7k_sync(struct qcaspi *qca, int event)
436 {
437         u16 signature = 0;
438         u16 spi_config;
439         u16 wrbuf_space = 0;
440         static u16 reset_count;
441
442         if (event == QCASPI_EVENT_CPUON) {
443                 /* Read signature twice, if not valid
444                  * go back to unknown state.
445                  */
446                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
447                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
448                 if (signature != QCASPI_GOOD_SIGNATURE) {
449                         qca->sync = QCASPI_SYNC_UNKNOWN;
450                         netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
451                 } else {
452                         /* ensure that the WRBUF is empty */
453                         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
454                                              &wrbuf_space);
455                         if (wrbuf_space != QCASPI_HW_BUF_LEN) {
456                                 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
457                                 qca->sync = QCASPI_SYNC_UNKNOWN;
458                         } else {
459                                 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
460                                 qca->sync = QCASPI_SYNC_READY;
461                                 return;
462                         }
463                 }
464         }
465
466         switch (qca->sync) {
467         case QCASPI_SYNC_READY:
468                 /* Read signature, if not valid go to unknown state. */
469                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
470                 if (signature != QCASPI_GOOD_SIGNATURE) {
471                         qca->sync = QCASPI_SYNC_UNKNOWN;
472                         netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
473                         /* don't reset right away */
474                         return;
475                 }
476                 break;
477         case QCASPI_SYNC_UNKNOWN:
478                 /* Read signature, if not valid stay in unknown state */
479                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
480                 if (signature != QCASPI_GOOD_SIGNATURE) {
481                         netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
482                         return;
483                 }
484
485                 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
486                 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
487                 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
488                 spi_config |= QCASPI_SLAVE_RESET_BIT;
489                 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config);
490
491                 qca->sync = QCASPI_SYNC_RESET;
492                 qca->stats.trig_reset++;
493                 reset_count = 0;
494                 break;
495         case QCASPI_SYNC_RESET:
496                 reset_count++;
497                 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
498                            reset_count);
499                 if (reset_count >= QCASPI_RESET_TIMEOUT) {
500                         /* reset did not seem to take place, try again */
501                         qca->sync = QCASPI_SYNC_UNKNOWN;
502                         qca->stats.reset_timeout++;
503                         netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
504                 }
505                 break;
506         }
507 }
508
509 static int
510 qcaspi_spi_thread(void *data)
511 {
512         struct qcaspi *qca = data;
513         u16 intr_cause = 0;
514
515         netdev_info(qca->net_dev, "SPI thread created\n");
516         while (!kthread_should_stop()) {
517                 set_current_state(TASK_INTERRUPTIBLE);
518                 if ((qca->intr_req == qca->intr_svc) &&
519                     (qca->txr.skb[qca->txr.head] == NULL) &&
520                     (qca->sync == QCASPI_SYNC_READY))
521                         schedule();
522
523                 set_current_state(TASK_RUNNING);
524
525                 netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
526                            qca->intr_req - qca->intr_svc,
527                            qca->txr.skb[qca->txr.head]);
528
529                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
530
531                 if (qca->sync != QCASPI_SYNC_READY) {
532                         netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
533                                    (unsigned int)qca->sync);
534                         netif_stop_queue(qca->net_dev);
535                         netif_carrier_off(qca->net_dev);
536                         qcaspi_flush_tx_ring(qca);
537                         msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
538                 }
539
540                 if (qca->intr_svc != qca->intr_req) {
541                         qca->intr_svc = qca->intr_req;
542                         start_spi_intr_handling(qca, &intr_cause);
543
544                         if (intr_cause & SPI_INT_CPU_ON) {
545                                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
546
547                                 /* not synced. */
548                                 if (qca->sync != QCASPI_SYNC_READY)
549                                         continue;
550
551                                 qca->stats.device_reset++;
552                                 netif_wake_queue(qca->net_dev);
553                                 netif_carrier_on(qca->net_dev);
554                         }
555
556                         if (intr_cause & SPI_INT_RDBUF_ERR) {
557                                 /* restart sync */
558                                 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
559                                 qca->stats.read_buf_err++;
560                                 qca->sync = QCASPI_SYNC_UNKNOWN;
561                                 continue;
562                         }
563
564                         if (intr_cause & SPI_INT_WRBUF_ERR) {
565                                 /* restart sync */
566                                 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
567                                 qca->stats.write_buf_err++;
568                                 qca->sync = QCASPI_SYNC_UNKNOWN;
569                                 continue;
570                         }
571
572                         /* can only handle other interrupts
573                          * if sync has occurred
574                          */
575                         if (qca->sync == QCASPI_SYNC_READY) {
576                                 if (intr_cause & SPI_INT_PKT_AVLBL)
577                                         qcaspi_receive(qca);
578                         }
579
580                         end_spi_intr_handling(qca, intr_cause);
581                 }
582
583                 if (qca->sync == QCASPI_SYNC_READY)
584                         qcaspi_transmit(qca);
585         }
586         set_current_state(TASK_RUNNING);
587         netdev_info(qca->net_dev, "SPI thread exit\n");
588
589         return 0;
590 }
591
592 static irqreturn_t
593 qcaspi_intr_handler(int irq, void *data)
594 {
595         struct qcaspi *qca = data;
596
597         qca->intr_req++;
598         if (qca->spi_thread &&
599             qca->spi_thread->state != TASK_RUNNING)
600                 wake_up_process(qca->spi_thread);
601
602         return IRQ_HANDLED;
603 }
604
605 int
606 qcaspi_netdev_open(struct net_device *dev)
607 {
608         struct qcaspi *qca = netdev_priv(dev);
609         int ret = 0;
610
611         if (!qca)
612                 return -EINVAL;
613
614         qca->intr_req = 1;
615         qca->intr_svc = 0;
616         qca->sync = QCASPI_SYNC_UNKNOWN;
617         qcafrm_fsm_init(&qca->frm_handle);
618
619         qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
620                                       qca, "%s", dev->name);
621
622         if (IS_ERR(qca->spi_thread)) {
623                 netdev_err(dev, "%s: unable to start kernel thread.\n",
624                            QCASPI_DRV_NAME);
625                 return PTR_ERR(qca->spi_thread);
626         }
627
628         ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
629                           dev->name, qca);
630         if (ret) {
631                 netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
632                            QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
633                 kthread_stop(qca->spi_thread);
634                 return ret;
635         }
636
637         netif_start_queue(qca->net_dev);
638
639         return 0;
640 }
641
642 int
643 qcaspi_netdev_close(struct net_device *dev)
644 {
645         struct qcaspi *qca = netdev_priv(dev);
646
647         netif_stop_queue(dev);
648
649         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
650         free_irq(qca->spi_dev->irq, qca);
651
652         kthread_stop(qca->spi_thread);
653         qca->spi_thread = NULL;
654         qcaspi_flush_tx_ring(qca);
655
656         return 0;
657 }
658
659 static netdev_tx_t
660 qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
661 {
662         u32 frame_len;
663         u8 *ptmp;
664         struct qcaspi *qca = netdev_priv(dev);
665         u16 new_tail;
666         struct sk_buff *tskb;
667         u8 pad_len = 0;
668
669         if (skb->len < QCAFRM_ETHMINLEN)
670                 pad_len = QCAFRM_ETHMINLEN - skb->len;
671
672         if (qca->txr.skb[qca->txr.tail]) {
673                 netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
674                 netif_stop_queue(qca->net_dev);
675                 qca->stats.ring_full++;
676                 return NETDEV_TX_BUSY;
677         }
678
679         if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
680             (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
681                 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
682                                        QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
683                 if (!tskb) {
684                         netdev_dbg(qca->net_dev, "could not allocate tx_buff\n");
685                         qca->stats.out_of_mem++;
686                         return NETDEV_TX_BUSY;
687                 }
688                 dev_kfree_skb(skb);
689                 skb = tskb;
690         }
691
692         frame_len = skb->len + pad_len;
693
694         ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
695         qcafrm_create_header(ptmp, frame_len);
696
697         if (pad_len) {
698                 ptmp = skb_put(skb, pad_len);
699                 memset(ptmp, 0, pad_len);
700         }
701
702         ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
703         qcafrm_create_footer(ptmp);
704
705         netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
706                    skb->len);
707
708         qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
709
710         new_tail = qca->txr.tail + 1;
711         if (new_tail >= qca->txr.count)
712                 new_tail = 0;
713
714         qca->txr.skb[qca->txr.tail] = skb;
715         qca->txr.tail = new_tail;
716
717         if (!qcaspi_tx_ring_has_space(&qca->txr)) {
718                 netif_stop_queue(qca->net_dev);
719                 qca->stats.ring_full++;
720         }
721
722         dev->trans_start = jiffies;
723
724         if (qca->spi_thread &&
725             qca->spi_thread->state != TASK_RUNNING)
726                 wake_up_process(qca->spi_thread);
727
728         return NETDEV_TX_OK;
729 }
730
731 static void
732 qcaspi_netdev_tx_timeout(struct net_device *dev)
733 {
734         struct qcaspi *qca = netdev_priv(dev);
735
736         netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
737                     jiffies, jiffies - dev->trans_start);
738         qca->net_dev->stats.tx_errors++;
739         /* wake the queue if there is room */
740         if (qcaspi_tx_ring_has_space(&qca->txr))
741                 netif_wake_queue(dev);
742 }
743
744 static int
745 qcaspi_netdev_init(struct net_device *dev)
746 {
747         struct qcaspi *qca = netdev_priv(dev);
748
749         dev->mtu = QCASPI_MTU;
750         dev->type = ARPHRD_ETHER;
751         qca->clkspeed = qcaspi_clkspeed;
752         qca->burst_len = qcaspi_burst_len;
753         qca->spi_thread = NULL;
754         qca->buffer_size = (dev->mtu + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
755                 QCAFRM_FOOTER_LEN + 4) * 4;
756
757         memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
758
759         qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
760         if (!qca->rx_buffer)
761                 return -ENOBUFS;
762
763         qca->rx_skb = netdev_alloc_skb(dev, qca->net_dev->mtu + VLAN_ETH_HLEN);
764         if (!qca->rx_skb) {
765                 kfree(qca->rx_buffer);
766                 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
767                 return -ENOBUFS;
768         }
769
770         return 0;
771 }
772
773 static void
774 qcaspi_netdev_uninit(struct net_device *dev)
775 {
776         struct qcaspi *qca = netdev_priv(dev);
777
778         kfree(qca->rx_buffer);
779         qca->buffer_size = 0;
780         if (qca->rx_skb)
781                 dev_kfree_skb(qca->rx_skb);
782 }
783
784 static int
785 qcaspi_netdev_change_mtu(struct net_device *dev, int new_mtu)
786 {
787         if ((new_mtu < QCAFRM_ETHMINMTU) || (new_mtu > QCAFRM_ETHMAXMTU))
788                 return -EINVAL;
789
790         dev->mtu = new_mtu;
791
792         return 0;
793 }
794
795 static const struct net_device_ops qcaspi_netdev_ops = {
796         .ndo_init = qcaspi_netdev_init,
797         .ndo_uninit = qcaspi_netdev_uninit,
798         .ndo_open = qcaspi_netdev_open,
799         .ndo_stop = qcaspi_netdev_close,
800         .ndo_start_xmit = qcaspi_netdev_xmit,
801         .ndo_change_mtu = qcaspi_netdev_change_mtu,
802         .ndo_set_mac_address = eth_mac_addr,
803         .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
804         .ndo_validate_addr = eth_validate_addr,
805 };
806
807 static void
808 qcaspi_netdev_setup(struct net_device *dev)
809 {
810         struct qcaspi *qca = NULL;
811
812         dev->netdev_ops = &qcaspi_netdev_ops;
813         qcaspi_set_ethtool_ops(dev);
814         dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
815         dev->flags = IFF_MULTICAST;
816         dev->tx_queue_len = 100;
817
818         qca = netdev_priv(dev);
819         memset(qca, 0, sizeof(struct qcaspi));
820
821         memset(&qca->spi_xfer1, 0, sizeof(struct spi_transfer));
822         memset(&qca->spi_xfer2, 0, sizeof(struct spi_transfer) * 2);
823
824         spi_message_init(&qca->spi_msg1);
825         spi_message_add_tail(&qca->spi_xfer1, &qca->spi_msg1);
826
827         spi_message_init(&qca->spi_msg2);
828         spi_message_add_tail(&qca->spi_xfer2[0], &qca->spi_msg2);
829         spi_message_add_tail(&qca->spi_xfer2[1], &qca->spi_msg2);
830
831         memset(&qca->txr, 0, sizeof(qca->txr));
832         qca->txr.count = TX_RING_MAX_LEN;
833 }
834
835 static const struct of_device_id qca_spi_of_match[] = {
836         { .compatible = "qca,qca7000" },
837         { /* sentinel */ }
838 };
839 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
840
841 static int
842 qca_spi_probe(struct spi_device *spi_device)
843 {
844         struct qcaspi *qca = NULL;
845         struct net_device *qcaspi_devs = NULL;
846         u8 legacy_mode = 0;
847         u16 signature;
848         const char *mac;
849
850         if (!spi_device->dev.of_node) {
851                 dev_err(&spi_device->dev, "Missing device tree\n");
852                 return -EINVAL;
853         }
854
855         legacy_mode = of_property_read_bool(spi_device->dev.of_node,
856                                             "qca,legacy-mode");
857
858         if (qcaspi_clkspeed == 0) {
859                 if (spi_device->max_speed_hz)
860                         qcaspi_clkspeed = spi_device->max_speed_hz;
861                 else
862                         qcaspi_clkspeed = QCASPI_CLK_SPEED;
863         }
864
865         if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
866             (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
867                 dev_info(&spi_device->dev, "Invalid clkspeed: %d\n",
868                          qcaspi_clkspeed);
869                 return -EINVAL;
870         }
871
872         if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
873             (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
874                 dev_info(&spi_device->dev, "Invalid burst len: %d\n",
875                          qcaspi_burst_len);
876                 return -EINVAL;
877         }
878
879         if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
880             (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
881                 dev_info(&spi_device->dev, "Invalid pluggable: %d\n",
882                          qcaspi_pluggable);
883                 return -EINVAL;
884         }
885
886         dev_info(&spi_device->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
887                  QCASPI_DRV_VERSION,
888                  qcaspi_clkspeed,
889                  qcaspi_burst_len,
890                  qcaspi_pluggable);
891
892         spi_device->mode = SPI_MODE_3;
893         spi_device->max_speed_hz = qcaspi_clkspeed;
894         if (spi_setup(spi_device) < 0) {
895                 dev_err(&spi_device->dev, "Unable to setup SPI device\n");
896                 return -EFAULT;
897         }
898
899         qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
900         if (!qcaspi_devs)
901                 return -ENOMEM;
902
903         qcaspi_netdev_setup(qcaspi_devs);
904
905         qca = netdev_priv(qcaspi_devs);
906         if (!qca) {
907                 free_netdev(qcaspi_devs);
908                 dev_err(&spi_device->dev, "Fail to retrieve private structure\n");
909                 return -ENOMEM;
910         }
911         qca->net_dev = qcaspi_devs;
912         qca->spi_dev = spi_device;
913         qca->legacy_mode = legacy_mode;
914
915         spi_set_drvdata(spi_device, qcaspi_devs);
916
917         mac = of_get_mac_address(spi_device->dev.of_node);
918
919         if (mac)
920                 ether_addr_copy(qca->net_dev->dev_addr, mac);
921
922         if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
923                 eth_hw_addr_random(qca->net_dev);
924                 dev_info(&spi_device->dev, "Using random MAC address: %pM\n",
925                          qca->net_dev->dev_addr);
926         }
927
928         netif_carrier_off(qca->net_dev);
929
930         if (!qcaspi_pluggable) {
931                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
932                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
933
934                 if (signature != QCASPI_GOOD_SIGNATURE) {
935                         dev_err(&spi_device->dev, "Invalid signature (0x%04X)\n",
936                                 signature);
937                         free_netdev(qcaspi_devs);
938                         return -EFAULT;
939                 }
940         }
941
942         if (register_netdev(qcaspi_devs)) {
943                 dev_info(&spi_device->dev, "Unable to register net device %s\n",
944                          qcaspi_devs->name);
945                 free_netdev(qcaspi_devs);
946                 return -EFAULT;
947         }
948
949         qcaspi_init_device_debugfs(qca);
950
951         return 0;
952 }
953
954 static int
955 qca_spi_remove(struct spi_device *spi_device)
956 {
957         struct net_device *qcaspi_devs = spi_get_drvdata(spi_device);
958         struct qcaspi *qca = netdev_priv(qcaspi_devs);
959
960         qcaspi_remove_device_debugfs(qca);
961
962         unregister_netdev(qcaspi_devs);
963         free_netdev(qcaspi_devs);
964
965         return 0;
966 }
967
968 static const struct spi_device_id qca_spi_id[] = {
969         { "qca7000", 0 },
970         { /* sentinel */ }
971 };
972 MODULE_DEVICE_TABLE(spi, qca_spi_id);
973
974 static struct spi_driver qca_spi_driver = {
975         .driver = {
976                 .name   = QCASPI_DRV_NAME,
977                 .owner  = THIS_MODULE,
978                 .of_match_table = qca_spi_of_match,
979         },
980         .id_table = qca_spi_id,
981         .probe    = qca_spi_probe,
982         .remove   = qca_spi_remove,
983 };
984 module_spi_driver(qca_spi_driver);
985
986 MODULE_DESCRIPTION("Qualcomm Atheros SPI Driver");
987 MODULE_AUTHOR("Qualcomm Atheros Communications");
988 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
989 MODULE_LICENSE("Dual BSD/GPL");
990 MODULE_VERSION(QCASPI_DRV_VERSION);