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_7k_common.h"
47#include "qca_debug.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
56static int qcaspi_clkspeed;
57module_param(qcaspi_clkspeed, int, 0);
58MODULE_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
62static int qcaspi_burst_len = MAX_DMA_BURST_LEN;
63module_param(qcaspi_burst_len, int, 0);
64MODULE_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
68static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
69module_param(qcaspi_pluggable, int, 0);
70MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
71
72#define QCASPI_WRITE_VERIFY_MIN 0
73#define QCASPI_WRITE_VERIFY_MAX 3
74static int wr_verify = QCASPI_WRITE_VERIFY_MIN;
75module_param(wr_verify, int, 0);
76MODULE_PARM_DESC(wr_verify, "SPI register write verify trails. Use 0-3.");
77
78#define QCASPI_TX_TIMEOUT (1 * HZ)
79#define QCASPI_QCA7K_REBOOT_TIME_MS 1000
80
81static void
82start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
83{
84	*intr_cause = 0;
85
86	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
87	qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
88	netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
89}
90
91static void
92end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
93{
94	u16 intr_enable = (SPI_INT_CPU_ON |
95			   SPI_INT_PKT_AVLBL |
96			   SPI_INT_RDBUF_ERR |
97			   SPI_INT_WRBUF_ERR);
98
99	qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause, 0);
100	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable, wr_verify);
101	netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
102}
103
104static u32
105qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
106{
107	__be16 cmd;
108	struct spi_message msg;
109	struct spi_transfer transfer[2];
110	int ret;
111
112	memset(&transfer, 0, sizeof(transfer));
113	spi_message_init(&msg);
114
115	cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
116	transfer[0].tx_buf = &cmd;
117	transfer[0].len = QCASPI_CMD_LEN;
118	transfer[1].tx_buf = src;
119	transfer[1].len = len;
120
121	spi_message_add_tail(&transfer[0], &msg);
122	spi_message_add_tail(&transfer[1], &msg);
123	ret = spi_sync(qca->spi_dev, &msg);
124
125	if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
126		qcaspi_spi_error(qca);
127		return 0;
128	}
129
130	return len;
131}
132
133static u32
134qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
135{
136	struct spi_message msg;
137	struct spi_transfer transfer;
138	int ret;
139
140	memset(&transfer, 0, sizeof(transfer));
141	spi_message_init(&msg);
142
143	transfer.tx_buf = src;
144	transfer.len = len;
145
146	spi_message_add_tail(&transfer, &msg);
147	ret = spi_sync(qca->spi_dev, &msg);
148
149	if (ret || (msg.actual_length != len)) {
150		qcaspi_spi_error(qca);
151		return 0;
152	}
153
154	return len;
155}
156
157static u32
158qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
159{
160	struct spi_message msg;
161	__be16 cmd;
162	struct spi_transfer transfer[2];
163	int ret;
164
165	memset(&transfer, 0, sizeof(transfer));
166	spi_message_init(&msg);
167
168	cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
169	transfer[0].tx_buf = &cmd;
170	transfer[0].len = QCASPI_CMD_LEN;
171	transfer[1].rx_buf = dst;
172	transfer[1].len = len;
173
174	spi_message_add_tail(&transfer[0], &msg);
175	spi_message_add_tail(&transfer[1], &msg);
176	ret = spi_sync(qca->spi_dev, &msg);
177
178	if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
179		qcaspi_spi_error(qca);
180		return 0;
181	}
182
183	return len;
184}
185
186static u32
187qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
188{
189	struct spi_message msg;
190	struct spi_transfer transfer;
191	int ret;
192
193	memset(&transfer, 0, sizeof(transfer));
194	spi_message_init(&msg);
195
196	transfer.rx_buf = dst;
197	transfer.len = len;
198
199	spi_message_add_tail(&transfer, &msg);
200	ret = spi_sync(qca->spi_dev, &msg);
201
202	if (ret || (msg.actual_length != len)) {
203		qcaspi_spi_error(qca);
204		return 0;
205	}
206
207	return len;
208}
209
210static int
211qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
212{
213	__be16 tx_data;
214	struct spi_message msg;
215	struct spi_transfer transfer;
216	int ret;
217
218	memset(&transfer, 0, sizeof(transfer));
219
220	spi_message_init(&msg);
221
222	tx_data = cpu_to_be16(cmd);
223	transfer.len = sizeof(cmd);
224	transfer.tx_buf = &tx_data;
225	spi_message_add_tail(&transfer, &msg);
226
227	ret = spi_sync(qca->spi_dev, &msg);
228
229	if (!ret)
230		ret = msg.status;
231
232	if (ret)
233		qcaspi_spi_error(qca);
234
235	return ret;
236}
237
238static int
239qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
240{
241	u32 count;
242	u32 written;
243	u32 offset;
244	u32 len;
245
246	len = skb->len;
247
248	qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len, wr_verify);
249	if (qca->legacy_mode)
250		qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
251
252	offset = 0;
253	while (len) {
254		count = len;
255		if (count > qca->burst_len)
256			count = qca->burst_len;
257
258		if (qca->legacy_mode) {
259			written = qcaspi_write_legacy(qca,
260						      skb->data + offset,
261						      count);
262		} else {
263			written = qcaspi_write_burst(qca,
264						     skb->data + offset,
265						     count);
266		}
267
268		if (written != count)
269			return -1;
270
271		offset += count;
272		len -= count;
273	}
274
275	return 0;
276}
277
278static int
279qcaspi_transmit(struct qcaspi *qca)
280{
281	struct net_device_stats *n_stats = &qca->net_dev->stats;
282	u16 available = 0;
283	u32 pkt_len;
284	u16 new_head;
285	u16 packets = 0;
286
287	if (qca->txr.skb[qca->txr.head] == NULL)
288		return 0;
289
290	qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
291
292	if (available > QCASPI_HW_BUF_LEN) {
293		/* This could only happen by interferences on the SPI line.
294		 * So retry later ...
295		 */
296		qca->stats.buf_avail_err++;
297		return -1;
298	}
299
300	while (qca->txr.skb[qca->txr.head]) {
301		pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
302
303		if (available < pkt_len) {
304			if (packets == 0)
305				qca->stats.write_buf_miss++;
306			break;
307		}
308
309		if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
310			qca->stats.write_err++;
311			return -1;
312		}
313
314		packets++;
315		n_stats->tx_packets++;
316		n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
317		available -= pkt_len;
318
319		/* remove the skb from the queue */
320		/* XXX After inconsistent lock states netif_tx_lock()
321		 * has been replaced by netif_tx_lock_bh() and so on.
322		 */
323		netif_tx_lock_bh(qca->net_dev);
324		dev_kfree_skb(qca->txr.skb[qca->txr.head]);
325		qca->txr.skb[qca->txr.head] = NULL;
326		qca->txr.size -= pkt_len;
327		new_head = qca->txr.head + 1;
328		if (new_head >= qca->txr.count)
329			new_head = 0;
330		qca->txr.head = new_head;
331		if (netif_queue_stopped(qca->net_dev))
332			netif_wake_queue(qca->net_dev);
333		netif_tx_unlock_bh(qca->net_dev);
334	}
335
336	return 0;
337}
338
339static int
340qcaspi_receive(struct qcaspi *qca)
341{
342	struct net_device *net_dev = qca->net_dev;
343	struct net_device_stats *n_stats = &net_dev->stats;
344	u16 available = 0;
345	u32 bytes_read;
346	u8 *cp;
347
348	/* Allocate rx SKB if we don't have one available. */
349	if (!qca->rx_skb) {
350		qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
351							net_dev->mtu +
352							VLAN_ETH_HLEN);
353		if (!qca->rx_skb) {
354			netdev_dbg(net_dev, "out of RX resources\n");
355			qca->stats.out_of_mem++;
356			return -1;
357		}
358	}
359
360	/* Read the packet size. */
361	qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
362
363	netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
364		   available);
365
366	if (available > QCASPI_HW_BUF_LEN + QCASPI_HW_PKT_LEN) {
367		/* This could only happen by interferences on the SPI line.
368		 * So retry later ...
369		 */
370		qca->stats.buf_avail_err++;
371		return -1;
372	} else if (available == 0) {
373		netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
374		return -1;
375	}
376
377	qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available, wr_verify);
378
379	if (qca->legacy_mode)
380		qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
381
382	while (available) {
383		u32 count = available;
384
385		if (count > qca->burst_len)
386			count = qca->burst_len;
387
388		if (qca->legacy_mode) {
389			bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
390							count);
391		} else {
392			bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
393						       count);
394		}
395
396		netdev_dbg(net_dev, "available: %d, byte read: %d\n",
397			   available, bytes_read);
398
399		if (bytes_read) {
400			available -= bytes_read;
401		} else {
402			qca->stats.read_err++;
403			return -1;
404		}
405
406		cp = qca->rx_buffer;
407
408		while ((bytes_read--) && (qca->rx_skb)) {
409			s32 retcode;
410
411			retcode = qcafrm_fsm_decode(&qca->frm_handle,
412						    qca->rx_skb->data,
413						    skb_tailroom(qca->rx_skb),
414						    *cp);
415			cp++;
416			switch (retcode) {
417			case QCAFRM_GATHER:
418			case QCAFRM_NOHEAD:
419				break;
420			case QCAFRM_NOTAIL:
421				netdev_dbg(net_dev, "no RX tail\n");
422				n_stats->rx_errors++;
423				n_stats->rx_dropped++;
424				break;
425			case QCAFRM_INVLEN:
426				netdev_dbg(net_dev, "invalid RX length\n");
427				n_stats->rx_errors++;
428				n_stats->rx_dropped++;
429				break;
430			default:
431				qca->rx_skb->dev = qca->net_dev;
432				n_stats->rx_packets++;
433				n_stats->rx_bytes += retcode;
434				skb_put(qca->rx_skb, retcode);
435				qca->rx_skb->protocol = eth_type_trans(
436					qca->rx_skb, qca->rx_skb->dev);
437				skb_checksum_none_assert(qca->rx_skb);
438				netif_rx_ni(qca->rx_skb);
439				qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
440					net_dev->mtu + VLAN_ETH_HLEN);
441				if (!qca->rx_skb) {
442					netdev_dbg(net_dev, "out of RX resources\n");
443					n_stats->rx_errors++;
444					qca->stats.out_of_mem++;
445					break;
446				}
447			}
448		}
449	}
450
451	return 0;
452}
453
454/*   Check that tx ring stores only so much bytes
455 *   that fit into the internal QCA buffer.
456 */
457
458static int
459qcaspi_tx_ring_has_space(struct tx_ring *txr)
460{
461	if (txr->skb[txr->tail])
462		return 0;
463
464	return (txr->size + QCAFRM_MAX_LEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
465}
466
467/*   Flush the tx ring. This function is only safe to
468 *   call from the qcaspi_spi_thread.
469 */
470
471static void
472qcaspi_flush_tx_ring(struct qcaspi *qca)
473{
474	int i;
475
476	/* XXX After inconsistent lock states netif_tx_lock()
477	 * has been replaced by netif_tx_lock_bh() and so on.
478	 */
479	netif_tx_lock_bh(qca->net_dev);
480	for (i = 0; i < TX_RING_MAX_LEN; i++) {
481		if (qca->txr.skb[i]) {
482			dev_kfree_skb(qca->txr.skb[i]);
483			qca->txr.skb[i] = NULL;
484			qca->net_dev->stats.tx_dropped++;
485		}
486	}
487	qca->txr.tail = 0;
488	qca->txr.head = 0;
489	qca->txr.size = 0;
490	netif_tx_unlock_bh(qca->net_dev);
491}
492
493static void
494qcaspi_qca7k_sync(struct qcaspi *qca, int event)
495{
496	u16 signature = 0;
497	u16 spi_config;
498	u16 wrbuf_space = 0;
499
500	if (event == QCASPI_EVENT_CPUON) {
501		/* Read signature twice, if not valid
502		 * go back to unknown state.
503		 */
504		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
505		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
506		if (signature != QCASPI_GOOD_SIGNATURE) {
507			qca->sync = QCASPI_SYNC_UNKNOWN;
508			netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
509		} else {
510			/* ensure that the WRBUF is empty */
511			qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
512					     &wrbuf_space);
513			if (wrbuf_space != QCASPI_HW_BUF_LEN) {
514				netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
515				qca->sync = QCASPI_SYNC_UNKNOWN;
516			} else {
517				netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
518				qca->sync = QCASPI_SYNC_READY;
519				return;
520			}
521		}
522	}
523
524	switch (qca->sync) {
525	case QCASPI_SYNC_READY:
526		/* Read signature, if not valid go to unknown state. */
527		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
528		if (signature != QCASPI_GOOD_SIGNATURE) {
529			qca->sync = QCASPI_SYNC_UNKNOWN;
530			netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
531			/* don't reset right away */
532			return;
533		}
534		break;
535	case QCASPI_SYNC_UNKNOWN:
536		/* Read signature, if not valid stay in unknown state */
537		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
538		if (signature != QCASPI_GOOD_SIGNATURE) {
539			netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
540			return;
541		}
542
543		/* TODO: use GPIO to reset QCA7000 in legacy mode*/
544		netdev_dbg(qca->net_dev, "sync: resetting device.\n");
545		qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
546		spi_config |= QCASPI_SLAVE_RESET_BIT;
547		qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config, 0);
548
549		qca->sync = QCASPI_SYNC_RESET;
550		qca->stats.trig_reset++;
551		qca->reset_count = 0;
552		break;
553	case QCASPI_SYNC_RESET:
554		qca->reset_count++;
555		netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
556			   qca->reset_count);
557		if (qca->reset_count >= QCASPI_RESET_TIMEOUT) {
558			/* reset did not seem to take place, try again */
559			qca->sync = QCASPI_SYNC_UNKNOWN;
560			qca->stats.reset_timeout++;
561			netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
562		}
563		break;
564	}
565}
566
567static int
568qcaspi_spi_thread(void *data)
569{
570	struct qcaspi *qca = data;
571	u16 intr_cause = 0;
572
573	netdev_info(qca->net_dev, "SPI thread created\n");
574	while (!kthread_should_stop()) {
575		set_current_state(TASK_INTERRUPTIBLE);
576		if (kthread_should_park()) {
577			netif_tx_disable(qca->net_dev);
578			netif_carrier_off(qca->net_dev);
579			qcaspi_flush_tx_ring(qca);
580			kthread_parkme();
581			if (qca->sync == QCASPI_SYNC_READY) {
582				netif_carrier_on(qca->net_dev);
583				netif_wake_queue(qca->net_dev);
584			}
585			continue;
586		}
587
588		if ((qca->intr_req == qca->intr_svc) &&
589		    !qca->txr.skb[qca->txr.head])
590			schedule();
591
592		set_current_state(TASK_RUNNING);
593
594		netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
595			   qca->intr_req - qca->intr_svc,
596			   qca->txr.skb[qca->txr.head]);
597
598		qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
599
600		if (qca->sync != QCASPI_SYNC_READY) {
601			netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
602				   (unsigned int)qca->sync);
603			netif_stop_queue(qca->net_dev);
604			netif_carrier_off(qca->net_dev);
605			qcaspi_flush_tx_ring(qca);
606			msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
607		}
608
609		if (qca->intr_svc != qca->intr_req) {
610			qca->intr_svc = qca->intr_req;
611			start_spi_intr_handling(qca, &intr_cause);
612
613			if (intr_cause & SPI_INT_CPU_ON) {
614				qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
615
616				/* Frame decoding in progress */
617				if (qca->frm_handle.state != qca->frm_handle.init)
618					qca->net_dev->stats.rx_dropped++;
619
620				qcafrm_fsm_init_spi(&qca->frm_handle);
621				qca->stats.device_reset++;
622
623				/* not synced. */
624				if (qca->sync != QCASPI_SYNC_READY)
625					continue;
626
627				netif_wake_queue(qca->net_dev);
628				netif_carrier_on(qca->net_dev);
629			}
630
631			if (intr_cause & SPI_INT_RDBUF_ERR) {
632				/* restart sync */
633				netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
634				qca->stats.read_buf_err++;
635				qca->sync = QCASPI_SYNC_UNKNOWN;
636				continue;
637			}
638
639			if (intr_cause & SPI_INT_WRBUF_ERR) {
640				/* restart sync */
641				netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
642				qca->stats.write_buf_err++;
643				qca->sync = QCASPI_SYNC_UNKNOWN;
644				continue;
645			}
646
647			/* can only handle other interrupts
648			 * if sync has occurred
649			 */
650			if (qca->sync == QCASPI_SYNC_READY) {
651				if (intr_cause & SPI_INT_PKT_AVLBL)
652					qcaspi_receive(qca);
653			}
654
655			end_spi_intr_handling(qca, intr_cause);
656		}
657
658		if (qca->sync == QCASPI_SYNC_READY)
659			qcaspi_transmit(qca);
660	}
661	set_current_state(TASK_RUNNING);
662	netdev_info(qca->net_dev, "SPI thread exit\n");
663
664	return 0;
665}
666
667static irqreturn_t
668qcaspi_intr_handler(int irq, void *data)
669{
670	struct qcaspi *qca = data;
671
672	qca->intr_req++;
673	if (qca->spi_thread &&
674	    qca->spi_thread->state != TASK_RUNNING)
675		wake_up_process(qca->spi_thread);
676
677	return IRQ_HANDLED;
678}
679
680static int
681qcaspi_netdev_open(struct net_device *dev)
682{
683	struct qcaspi *qca = netdev_priv(dev);
684	int ret = 0;
685
686	if (!qca)
687		return -EINVAL;
688
689	qca->intr_req = 1;
690	qca->intr_svc = 0;
691	qca->sync = QCASPI_SYNC_UNKNOWN;
692	qcafrm_fsm_init_spi(&qca->frm_handle);
693
694	qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
695				      qca, "%s", dev->name);
696
697	if (IS_ERR(qca->spi_thread)) {
698		netdev_err(dev, "%s: unable to start kernel thread.\n",
699			   QCASPI_DRV_NAME);
700		return PTR_ERR(qca->spi_thread);
701	}
702
703	ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
704			  dev->name, qca);
705	if (ret) {
706		netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
707			   QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
708		kthread_stop(qca->spi_thread);
709		return ret;
710	}
711
712	/* SPI thread takes care of TX queue */
713
714	return 0;
715}
716
717static int
718qcaspi_netdev_close(struct net_device *dev)
719{
720	struct qcaspi *qca = netdev_priv(dev);
721
722	netif_stop_queue(dev);
723
724	qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
725	free_irq(qca->spi_dev->irq, qca);
726
727	kthread_stop(qca->spi_thread);
728	qca->spi_thread = NULL;
729	qcaspi_flush_tx_ring(qca);
730
731	return 0;
732}
733
734static netdev_tx_t
735qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
736{
737	u32 frame_len;
738	u8 *ptmp;
739	struct qcaspi *qca = netdev_priv(dev);
740	u16 new_tail;
741	struct sk_buff *tskb;
742	u8 pad_len = 0;
743
744	if (skb->len < QCAFRM_MIN_LEN)
745		pad_len = QCAFRM_MIN_LEN - skb->len;
746
747	if (qca->txr.skb[qca->txr.tail]) {
748		netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
749		netif_stop_queue(qca->net_dev);
750		qca->stats.ring_full++;
751		return NETDEV_TX_BUSY;
752	}
753
754	if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
755	    (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
756		tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
757				       QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
758		if (!tskb) {
759			qca->stats.out_of_mem++;
760			return NETDEV_TX_BUSY;
761		}
762		dev_kfree_skb(skb);
763		skb = tskb;
764	}
765
766	frame_len = skb->len + pad_len;
767
768	ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
769	qcafrm_create_header(ptmp, frame_len);
770
771	if (pad_len) {
772		ptmp = skb_put_zero(skb, pad_len);
773	}
774
775	ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
776	qcafrm_create_footer(ptmp);
777
778	netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
779		   skb->len);
780
781	qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
782
783	new_tail = qca->txr.tail + 1;
784	if (new_tail >= qca->txr.count)
785		new_tail = 0;
786
787	qca->txr.skb[qca->txr.tail] = skb;
788	qca->txr.tail = new_tail;
789
790	if (!qcaspi_tx_ring_has_space(&qca->txr)) {
791		netif_stop_queue(qca->net_dev);
792		qca->stats.ring_full++;
793	}
794
795	netif_trans_update(dev);
796
797	if (qca->spi_thread &&
798	    qca->spi_thread->state != TASK_RUNNING)
799		wake_up_process(qca->spi_thread);
800
801	return NETDEV_TX_OK;
802}
803
804static void
805qcaspi_netdev_tx_timeout(struct net_device *dev, unsigned int txqueue)
806{
807	struct qcaspi *qca = netdev_priv(dev);
808
809	netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
810		    jiffies, jiffies - dev_trans_start(dev));
811	qca->net_dev->stats.tx_errors++;
812	/* Trigger tx queue flush and QCA7000 reset */
813	qca->sync = QCASPI_SYNC_UNKNOWN;
814
815	if (qca->spi_thread)
816		wake_up_process(qca->spi_thread);
817}
818
819static int
820qcaspi_netdev_init(struct net_device *dev)
821{
822	struct qcaspi *qca = netdev_priv(dev);
823
824	dev->mtu = QCAFRM_MAX_MTU;
825	dev->type = ARPHRD_ETHER;
826	qca->clkspeed = qcaspi_clkspeed;
827	qca->burst_len = qcaspi_burst_len;
828	qca->spi_thread = NULL;
829	qca->buffer_size = (dev->mtu + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
830		QCAFRM_FOOTER_LEN + 4) * 4;
831
832	memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
833
834	qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
835	if (!qca->rx_buffer)
836		return -ENOBUFS;
837
838	qca->rx_skb = netdev_alloc_skb_ip_align(dev, qca->net_dev->mtu +
839						VLAN_ETH_HLEN);
840	if (!qca->rx_skb) {
841		kfree(qca->rx_buffer);
842		netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
843		return -ENOBUFS;
844	}
845
846	return 0;
847}
848
849static void
850qcaspi_netdev_uninit(struct net_device *dev)
851{
852	struct qcaspi *qca = netdev_priv(dev);
853
854	kfree(qca->rx_buffer);
855	qca->buffer_size = 0;
856	dev_kfree_skb(qca->rx_skb);
857}
858
859static const struct net_device_ops qcaspi_netdev_ops = {
860	.ndo_init = qcaspi_netdev_init,
861	.ndo_uninit = qcaspi_netdev_uninit,
862	.ndo_open = qcaspi_netdev_open,
863	.ndo_stop = qcaspi_netdev_close,
864	.ndo_start_xmit = qcaspi_netdev_xmit,
865	.ndo_set_mac_address = eth_mac_addr,
866	.ndo_tx_timeout = qcaspi_netdev_tx_timeout,
867	.ndo_validate_addr = eth_validate_addr,
868};
869
870static void
871qcaspi_netdev_setup(struct net_device *dev)
872{
873	struct qcaspi *qca = NULL;
874
875	dev->netdev_ops = &qcaspi_netdev_ops;
876	qcaspi_set_ethtool_ops(dev);
877	dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
878	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
879	dev->tx_queue_len = 100;
880
881	/* MTU range: 46 - 1500 */
882	dev->min_mtu = QCAFRM_MIN_MTU;
883	dev->max_mtu = QCAFRM_MAX_MTU;
884
885	qca = netdev_priv(dev);
886	memset(qca, 0, sizeof(struct qcaspi));
887
888	memset(&qca->txr, 0, sizeof(qca->txr));
889	qca->txr.count = TX_RING_MAX_LEN;
890}
891
892static const struct of_device_id qca_spi_of_match[] = {
893	{ .compatible = "qca,qca7000" },
894	{ /* sentinel */ }
895};
896MODULE_DEVICE_TABLE(of, qca_spi_of_match);
897
898static int
899qca_spi_probe(struct spi_device *spi)
900{
901	struct qcaspi *qca = NULL;
902	struct net_device *qcaspi_devs = NULL;
903	u8 legacy_mode = 0;
904	u16 signature;
905	const char *mac;
906
907	if (!spi->dev.of_node) {
908		dev_err(&spi->dev, "Missing device tree\n");
909		return -EINVAL;
910	}
911
912	legacy_mode = of_property_read_bool(spi->dev.of_node,
913					    "qca,legacy-mode");
914
915	if (qcaspi_clkspeed == 0) {
916		if (spi->max_speed_hz)
917			qcaspi_clkspeed = spi->max_speed_hz;
918		else
919			qcaspi_clkspeed = QCASPI_CLK_SPEED;
920	}
921
922	if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
923	    (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
924		dev_err(&spi->dev, "Invalid clkspeed: %d\n",
925			qcaspi_clkspeed);
926		return -EINVAL;
927	}
928
929	if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
930	    (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
931		dev_err(&spi->dev, "Invalid burst len: %d\n",
932			qcaspi_burst_len);
933		return -EINVAL;
934	}
935
936	if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
937	    (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
938		dev_err(&spi->dev, "Invalid pluggable: %d\n",
939			qcaspi_pluggable);
940		return -EINVAL;
941	}
942
943	if (wr_verify < QCASPI_WRITE_VERIFY_MIN ||
944	    wr_verify > QCASPI_WRITE_VERIFY_MAX) {
945		dev_err(&spi->dev, "Invalid write verify: %d\n",
946			wr_verify);
947		return -EINVAL;
948	}
949
950	dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
951		 QCASPI_DRV_VERSION,
952		 qcaspi_clkspeed,
953		 qcaspi_burst_len,
954		 qcaspi_pluggable);
955
956	spi->mode = SPI_MODE_3;
957	spi->max_speed_hz = qcaspi_clkspeed;
958	if (spi_setup(spi) < 0) {
959		dev_err(&spi->dev, "Unable to setup SPI device\n");
960		return -EFAULT;
961	}
962
963	qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
964	if (!qcaspi_devs)
965		return -ENOMEM;
966
967	qcaspi_netdev_setup(qcaspi_devs);
968	SET_NETDEV_DEV(qcaspi_devs, &spi->dev);
969
970	qca = netdev_priv(qcaspi_devs);
971	if (!qca) {
972		free_netdev(qcaspi_devs);
973		dev_err(&spi->dev, "Fail to retrieve private structure\n");
974		return -ENOMEM;
975	}
976	qca->net_dev = qcaspi_devs;
977	qca->spi_dev = spi;
978	qca->legacy_mode = legacy_mode;
979
980	spi_set_drvdata(spi, qcaspi_devs);
981
982	mac = of_get_mac_address(spi->dev.of_node);
983
984	if (!IS_ERR(mac))
985		ether_addr_copy(qca->net_dev->dev_addr, mac);
986
987	if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
988		eth_hw_addr_random(qca->net_dev);
989		dev_info(&spi->dev, "Using random MAC address: %pM\n",
990			 qca->net_dev->dev_addr);
991	}
992
993	netif_carrier_off(qca->net_dev);
994
995	if (!qcaspi_pluggable) {
996		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
997		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
998
999		if (signature != QCASPI_GOOD_SIGNATURE) {
1000			dev_err(&spi->dev, "Invalid signature (0x%04X)\n",
1001				signature);
1002			free_netdev(qcaspi_devs);
1003			return -EFAULT;
1004		}
1005	}
1006
1007	if (register_netdev(qcaspi_devs)) {
1008		dev_err(&spi->dev, "Unable to register net device %s\n",
1009			qcaspi_devs->name);
1010		free_netdev(qcaspi_devs);
1011		return -EFAULT;
1012	}
1013
1014	qcaspi_init_device_debugfs(qca);
1015
1016	return 0;
1017}
1018
1019static int
1020qca_spi_remove(struct spi_device *spi)
1021{
1022	struct net_device *qcaspi_devs = spi_get_drvdata(spi);
1023	struct qcaspi *qca = netdev_priv(qcaspi_devs);
1024
1025	qcaspi_remove_device_debugfs(qca);
1026
1027	unregister_netdev(qcaspi_devs);
1028	free_netdev(qcaspi_devs);
1029
1030	return 0;
1031}
1032
1033static const struct spi_device_id qca_spi_id[] = {
1034	{ "qca7000", 0 },
1035	{ /* sentinel */ }
1036};
1037MODULE_DEVICE_TABLE(spi, qca_spi_id);
1038
1039static struct spi_driver qca_spi_driver = {
1040	.driver	= {
1041		.name	= QCASPI_DRV_NAME,
1042		.of_match_table = qca_spi_of_match,
1043	},
1044	.id_table = qca_spi_id,
1045	.probe    = qca_spi_probe,
1046	.remove   = qca_spi_remove,
1047};
1048module_spi_driver(qca_spi_driver);
1049
1050MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");
1051MODULE_AUTHOR("Qualcomm Atheros Communications");
1052MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
1053MODULE_LICENSE("Dual BSD/GPL");
1054MODULE_VERSION(QCASPI_DRV_VERSION);
1055