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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Freescale QMC HDLC Device Driver
  4 *
  5 * Copyright 2023 CS GROUP France
  6 *
  7 * Author: Herve Codina <herve.codina@bootlin.com>
  8 */
  9
 10#include <linux/array_size.h>
 11#include <linux/bug.h>
 12#include <linux/cleanup.h>
 13#include <linux/bitmap.h>
 14#include <linux/dma-mapping.h>
 15#include <linux/device.h>
 16#include <linux/err.h>
 17#include <linux/framer/framer.h>
 18#include <linux/hdlc.h>
 19#include <linux/mod_devicetable.h>
 20#include <linux/module.h>
 21#include <linux/platform_device.h>
 22#include <linux/slab.h>
 23#include <linux/spinlock.h>
 24#include <linux/types.h>
 25
 26#include <soc/fsl/qe/qmc.h>
 27
 28struct qmc_hdlc_desc {
 29	struct net_device *netdev;
 30	struct sk_buff *skb; /* NULL if the descriptor is not in use */
 31	dma_addr_t dma_addr;
 32	size_t dma_size;
 33};
 34
 35struct qmc_hdlc {
 36	struct device *dev;
 37	struct qmc_chan *qmc_chan;
 38	struct net_device *netdev;
 39	struct framer *framer;
 40	spinlock_t carrier_lock; /* Protect carrier detection */
 41	struct notifier_block nb;
 42	bool is_crc32;
 43	spinlock_t tx_lock; /* Protect tx descriptors */
 44	struct qmc_hdlc_desc tx_descs[8];
 45	unsigned int tx_out;
 46	struct qmc_hdlc_desc rx_descs[4];
 47	u32 slot_map;
 48};
 49
 50static struct qmc_hdlc *netdev_to_qmc_hdlc(struct net_device *netdev)
 51{
 52	return dev_to_hdlc(netdev)->priv;
 53}
 54
 55static int qmc_hdlc_framer_set_carrier(struct qmc_hdlc *qmc_hdlc)
 56{
 57	struct framer_status framer_status;
 58	int ret;
 59
 60	if (!qmc_hdlc->framer)
 61		return 0;
 62
 63	guard(spinlock_irqsave)(&qmc_hdlc->carrier_lock);
 64
 65	ret = framer_get_status(qmc_hdlc->framer, &framer_status);
 66	if (ret) {
 67		dev_err(qmc_hdlc->dev, "get framer status failed (%d)\n", ret);
 68		return ret;
 69	}
 70	if (framer_status.link_is_on)
 71		netif_carrier_on(qmc_hdlc->netdev);
 72	else
 73		netif_carrier_off(qmc_hdlc->netdev);
 74
 75	return 0;
 76}
 77
 78static int qmc_hdlc_framer_notifier(struct notifier_block *nb, unsigned long action,
 79				    void *data)
 80{
 81	struct qmc_hdlc *qmc_hdlc = container_of(nb, struct qmc_hdlc, nb);
 82	int ret;
 83
 84	if (action != FRAMER_EVENT_STATUS)
 85		return NOTIFY_DONE;
 86
 87	ret = qmc_hdlc_framer_set_carrier(qmc_hdlc);
 88	return ret ? NOTIFY_DONE : NOTIFY_OK;
 89}
 90
 91static int qmc_hdlc_framer_start(struct qmc_hdlc *qmc_hdlc)
 92{
 93	struct framer_status framer_status;
 94	int ret;
 95
 96	if (!qmc_hdlc->framer)
 97		return 0;
 98
 99	ret = framer_power_on(qmc_hdlc->framer);
100	if (ret) {
101		dev_err(qmc_hdlc->dev, "framer power-on failed (%d)\n", ret);
102		return ret;
103	}
104
105	/* Be sure that get_status is supported */
106	ret = framer_get_status(qmc_hdlc->framer, &framer_status);
107	if (ret) {
108		dev_err(qmc_hdlc->dev, "get framer status failed (%d)\n", ret);
109		goto framer_power_off;
110	}
111
112	qmc_hdlc->nb.notifier_call = qmc_hdlc_framer_notifier;
113	ret = framer_notifier_register(qmc_hdlc->framer, &qmc_hdlc->nb);
114	if (ret) {
115		dev_err(qmc_hdlc->dev, "framer notifier register failed (%d)\n", ret);
116		goto framer_power_off;
117	}
118
119	return 0;
120
121framer_power_off:
122	framer_power_off(qmc_hdlc->framer);
123	return ret;
124}
125
126static void qmc_hdlc_framer_stop(struct qmc_hdlc *qmc_hdlc)
127{
128	if (!qmc_hdlc->framer)
129		return;
130
131	framer_notifier_unregister(qmc_hdlc->framer, &qmc_hdlc->nb);
132	framer_power_off(qmc_hdlc->framer);
133}
134
135static int qmc_hdlc_framer_set_iface(struct qmc_hdlc *qmc_hdlc, int if_iface,
136				     const te1_settings *te1)
137{
138	struct framer_config config;
139	int ret;
140
141	if (!qmc_hdlc->framer)
142		return 0;
143
144	ret = framer_get_config(qmc_hdlc->framer, &config);
145	if (ret)
146		return ret;
147
148	switch (if_iface) {
149	case IF_IFACE_E1:
150		config.iface = FRAMER_IFACE_E1;
151		break;
152	case IF_IFACE_T1:
153		config.iface = FRAMER_IFACE_T1;
154		break;
155	default:
156		return -EINVAL;
157	}
158
159	switch (te1->clock_type) {
160	case CLOCK_DEFAULT:
161		/* Keep current value */
162		break;
163	case CLOCK_EXT:
164		config.clock_type = FRAMER_CLOCK_EXT;
165		break;
166	case CLOCK_INT:
167		config.clock_type = FRAMER_CLOCK_INT;
168		break;
169	default:
170		return -EINVAL;
171	}
172	config.line_clock_rate = te1->clock_rate;
173
174	return framer_set_config(qmc_hdlc->framer, &config);
175}
176
177static int qmc_hdlc_framer_get_iface(struct qmc_hdlc *qmc_hdlc, int *if_iface, te1_settings *te1)
178{
179	struct framer_config config;
180	int ret;
181
182	if (!qmc_hdlc->framer) {
183		*if_iface = IF_IFACE_E1;
184		return 0;
185	}
186
187	ret = framer_get_config(qmc_hdlc->framer, &config);
188	if (ret)
189		return ret;
190
191	switch (config.iface) {
192	case FRAMER_IFACE_E1:
193		*if_iface = IF_IFACE_E1;
194		break;
195	case FRAMER_IFACE_T1:
196		*if_iface = IF_IFACE_T1;
197		break;
198	}
199
200	if (!te1)
201		return 0; /* Only iface type requested */
202
203	switch (config.clock_type) {
204	case FRAMER_CLOCK_EXT:
205		te1->clock_type = CLOCK_EXT;
206		break;
207	case FRAMER_CLOCK_INT:
208		te1->clock_type = CLOCK_INT;
209		break;
210	default:
211		return -EINVAL;
212	}
213	te1->clock_rate = config.line_clock_rate;
214	return 0;
215}
216
217static int qmc_hdlc_framer_init(struct qmc_hdlc *qmc_hdlc)
218{
219	int ret;
220
221	if (!qmc_hdlc->framer)
222		return 0;
223
224	ret = framer_init(qmc_hdlc->framer);
225	if (ret) {
226		dev_err(qmc_hdlc->dev, "framer init failed (%d)\n", ret);
227		return ret;
228	}
229
230	return 0;
231}
232
233static void qmc_hdlc_framer_exit(struct qmc_hdlc *qmc_hdlc)
234{
235	if (!qmc_hdlc->framer)
236		return;
237
238	framer_exit(qmc_hdlc->framer);
239}
240
241static int qmc_hdlc_recv_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc, size_t size);
242
243#define QMC_HDLC_RX_ERROR_FLAGS				\
244	(QMC_RX_FLAG_HDLC_OVF | QMC_RX_FLAG_HDLC_UNA |	\
245	 QMC_RX_FLAG_HDLC_CRC | QMC_RX_FLAG_HDLC_ABORT)
246
247static void qmc_hcld_recv_complete(void *context, size_t length, unsigned int flags)
248{
249	struct qmc_hdlc_desc *desc = context;
250	struct net_device *netdev;
251	struct qmc_hdlc *qmc_hdlc;
252	int ret;
253
254	netdev = desc->netdev;
255	qmc_hdlc = netdev_to_qmc_hdlc(netdev);
256
257	dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_FROM_DEVICE);
258
259	if (flags & QMC_HDLC_RX_ERROR_FLAGS) {
260		netdev->stats.rx_errors++;
261		if (flags & QMC_RX_FLAG_HDLC_OVF) /* Data overflow */
262			netdev->stats.rx_over_errors++;
263		if (flags & QMC_RX_FLAG_HDLC_UNA) /* bits received not multiple of 8 */
264			netdev->stats.rx_frame_errors++;
265		if (flags & QMC_RX_FLAG_HDLC_ABORT) /* Received an abort sequence */
266			netdev->stats.rx_frame_errors++;
267		if (flags & QMC_RX_FLAG_HDLC_CRC) /* CRC error */
268			netdev->stats.rx_crc_errors++;
269		kfree_skb(desc->skb);
270	} else {
271		netdev->stats.rx_packets++;
272		netdev->stats.rx_bytes += length;
273
274		skb_put(desc->skb, length);
275		desc->skb->protocol = hdlc_type_trans(desc->skb, netdev);
276		netif_rx(desc->skb);
277	}
278
279	/* Re-queue a transfer using the same descriptor */
280	ret = qmc_hdlc_recv_queue(qmc_hdlc, desc, desc->dma_size);
281	if (ret) {
282		dev_err(qmc_hdlc->dev, "queue recv desc failed (%d)\n", ret);
283		netdev->stats.rx_errors++;
284	}
285}
286
287static int qmc_hdlc_recv_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc, size_t size)
288{
289	int ret;
290
291	desc->skb = dev_alloc_skb(size);
292	if (!desc->skb)
293		return -ENOMEM;
294
295	desc->dma_size = size;
296	desc->dma_addr = dma_map_single(qmc_hdlc->dev, desc->skb->data,
297					desc->dma_size, DMA_FROM_DEVICE);
298	ret = dma_mapping_error(qmc_hdlc->dev, desc->dma_addr);
299	if (ret)
300		goto free_skb;
301
302	ret = qmc_chan_read_submit(qmc_hdlc->qmc_chan, desc->dma_addr, desc->dma_size,
303				   qmc_hcld_recv_complete, desc);
304	if (ret)
305		goto dma_unmap;
306
307	return 0;
308
309dma_unmap:
310	dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_FROM_DEVICE);
311free_skb:
312	kfree_skb(desc->skb);
313	desc->skb = NULL;
314	return ret;
315}
316
317static void qmc_hdlc_xmit_complete(void *context)
318{
319	struct qmc_hdlc_desc *desc = context;
320	struct net_device *netdev;
321	struct qmc_hdlc *qmc_hdlc;
322	struct sk_buff *skb;
323
324	netdev = desc->netdev;
325	qmc_hdlc = netdev_to_qmc_hdlc(netdev);
326
327	scoped_guard(spinlock_irqsave, &qmc_hdlc->tx_lock) {
328		dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_TO_DEVICE);
329		skb = desc->skb;
330		desc->skb = NULL; /* Release the descriptor */
331		if (netif_queue_stopped(netdev))
332			netif_wake_queue(netdev);
333	}
334
335	netdev->stats.tx_packets++;
336	netdev->stats.tx_bytes += skb->len;
337
338	dev_consume_skb_any(skb);
339}
340
341static int qmc_hdlc_xmit_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdlc_desc *desc)
342{
343	int ret;
344
345	desc->dma_addr = dma_map_single(qmc_hdlc->dev, desc->skb->data,
346					desc->dma_size, DMA_TO_DEVICE);
347	ret = dma_mapping_error(qmc_hdlc->dev, desc->dma_addr);
348	if (ret) {
349		dev_err(qmc_hdlc->dev, "failed to map skb\n");
350		return ret;
351	}
352
353	ret = qmc_chan_write_submit(qmc_hdlc->qmc_chan, desc->dma_addr, desc->dma_size,
354				    qmc_hdlc_xmit_complete, desc);
355	if (ret) {
356		dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_TO_DEVICE);
357		dev_err(qmc_hdlc->dev, "qmc chan write returns %d\n", ret);
358		return ret;
359	}
360
361	return 0;
362}
363
364static netdev_tx_t qmc_hdlc_xmit(struct sk_buff *skb, struct net_device *netdev)
365{
366	struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
367	struct qmc_hdlc_desc *desc;
368	int err;
369
370	guard(spinlock_irqsave)(&qmc_hdlc->tx_lock);
371
372	desc = &qmc_hdlc->tx_descs[qmc_hdlc->tx_out];
373	if (WARN_ONCE(desc->skb, "No tx descriptors available\n")) {
374		/* Should never happen.
375		 * Previous xmit should have already stopped the queue.
376		 */
377		netif_stop_queue(netdev);
378		return NETDEV_TX_BUSY;
379	}
380
381	desc->netdev = netdev;
382	desc->dma_size = skb->len;
383	desc->skb = skb;
384	err = qmc_hdlc_xmit_queue(qmc_hdlc, desc);
385	if (err) {
386		desc->skb = NULL; /* Release the descriptor */
387		if (err == -EBUSY) {
388			netif_stop_queue(netdev);
389			return NETDEV_TX_BUSY;
390		}
391		dev_kfree_skb(skb);
392		netdev->stats.tx_dropped++;
393		return NETDEV_TX_OK;
394	}
395
396	qmc_hdlc->tx_out = (qmc_hdlc->tx_out + 1) % ARRAY_SIZE(qmc_hdlc->tx_descs);
397
398	if (qmc_hdlc->tx_descs[qmc_hdlc->tx_out].skb)
399		netif_stop_queue(netdev);
400
401	return NETDEV_TX_OK;
402}
403
404static int qmc_hdlc_xlate_slot_map(struct qmc_hdlc *qmc_hdlc,
405				   u32 slot_map, struct qmc_chan_ts_info *ts_info)
406{
407	DECLARE_BITMAP(ts_mask_avail, 64);
408	DECLARE_BITMAP(ts_mask, 64);
409	DECLARE_BITMAP(map, 64);
410
411	/* Tx and Rx available masks must be identical */
412	if (ts_info->rx_ts_mask_avail != ts_info->tx_ts_mask_avail) {
413		dev_err(qmc_hdlc->dev, "tx and rx available timeslots mismatch (0x%llx, 0x%llx)\n",
414			ts_info->rx_ts_mask_avail, ts_info->tx_ts_mask_avail);
415		return -EINVAL;
416	}
417
418	bitmap_from_u64(ts_mask_avail, ts_info->rx_ts_mask_avail);
419	bitmap_from_u64(map, slot_map);
420	bitmap_scatter(ts_mask, map, ts_mask_avail, 64);
421
422	if (bitmap_weight(ts_mask, 64) != bitmap_weight(map, 64)) {
423		dev_err(qmc_hdlc->dev, "Cannot translate timeslots %64pb -> (%64pb, %64pb)\n",
424			map, ts_mask_avail, ts_mask);
425		return -EINVAL;
426	}
427
428	bitmap_to_arr64(&ts_info->tx_ts_mask, ts_mask, 64);
429	ts_info->rx_ts_mask = ts_info->tx_ts_mask;
430	return 0;
431}
432
433static int qmc_hdlc_xlate_ts_info(struct qmc_hdlc *qmc_hdlc,
434				  const struct qmc_chan_ts_info *ts_info, u32 *slot_map)
435{
436	DECLARE_BITMAP(ts_mask_avail, 64);
437	DECLARE_BITMAP(ts_mask, 64);
438	DECLARE_BITMAP(map, 64);
439	u32 slot_array[2];
440
441	/* Tx and Rx masks and available masks must be identical */
442	if (ts_info->rx_ts_mask_avail != ts_info->tx_ts_mask_avail) {
443		dev_err(qmc_hdlc->dev, "tx and rx available timeslots mismatch (0x%llx, 0x%llx)\n",
444			ts_info->rx_ts_mask_avail, ts_info->tx_ts_mask_avail);
445		return -EINVAL;
446	}
447	if (ts_info->rx_ts_mask != ts_info->tx_ts_mask) {
448		dev_err(qmc_hdlc->dev, "tx and rx timeslots mismatch (0x%llx, 0x%llx)\n",
449			ts_info->rx_ts_mask, ts_info->tx_ts_mask);
450		return -EINVAL;
451	}
452
453	bitmap_from_u64(ts_mask_avail, ts_info->rx_ts_mask_avail);
454	bitmap_from_u64(ts_mask, ts_info->rx_ts_mask);
455	bitmap_gather(map, ts_mask, ts_mask_avail, 64);
456
457	if (bitmap_weight(ts_mask, 64) != bitmap_weight(map, 64)) {
458		dev_err(qmc_hdlc->dev, "Cannot translate timeslots (%64pb, %64pb) -> %64pb\n",
459			ts_mask_avail, ts_mask, map);
460		return -EINVAL;
461	}
462
463	bitmap_to_arr32(slot_array, map, 64);
464	if (slot_array[1]) {
465		dev_err(qmc_hdlc->dev, "Slot map out of 32bit (%64pb, %64pb) -> %64pb\n",
466			ts_mask_avail, ts_mask, map);
467		return -EINVAL;
468	}
469
470	*slot_map = slot_array[0];
471	return 0;
472}
473
474static int qmc_hdlc_set_iface(struct qmc_hdlc *qmc_hdlc, int if_iface, const te1_settings *te1)
475{
476	struct qmc_chan_ts_info ts_info;
477	int ret;
478
479	ret = qmc_chan_get_ts_info(qmc_hdlc->qmc_chan, &ts_info);
480	if (ret) {
481		dev_err(qmc_hdlc->dev, "get QMC channel ts info failed %d\n", ret);
482		return ret;
483	}
484	ret = qmc_hdlc_xlate_slot_map(qmc_hdlc, te1->slot_map, &ts_info);
485	if (ret)
486		return ret;
487
488	ret = qmc_chan_set_ts_info(qmc_hdlc->qmc_chan, &ts_info);
489	if (ret) {
490		dev_err(qmc_hdlc->dev, "set QMC channel ts info failed %d\n", ret);
491		return ret;
492	}
493
494	qmc_hdlc->slot_map = te1->slot_map;
495
496	ret = qmc_hdlc_framer_set_iface(qmc_hdlc, if_iface, te1);
497	if (ret) {
498		dev_err(qmc_hdlc->dev, "framer set iface failed %d\n", ret);
499		return ret;
500	}
501
502	return 0;
503}
504
505static int qmc_hdlc_ioctl(struct net_device *netdev, struct if_settings *ifs)
506{
507	struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
508	te1_settings te1;
509	int ret;
510
511	switch (ifs->type) {
512	case IF_GET_IFACE:
513		if (ifs->size < sizeof(te1)) {
514			/* Retrieve type only */
515			ret = qmc_hdlc_framer_get_iface(qmc_hdlc, &ifs->type, NULL);
516			if (ret)
517				return ret;
518
519			if (!ifs->size)
520				return 0; /* only type requested */
521
522			ifs->size = sizeof(te1); /* data size wanted */
523			return -ENOBUFS;
524		}
525
526		memset(&te1, 0, sizeof(te1));
527
528		/* Retrieve info from framer */
529		ret = qmc_hdlc_framer_get_iface(qmc_hdlc, &ifs->type, &te1);
530		if (ret)
531			return ret;
532
533		/* Update slot_map */
534		te1.slot_map = qmc_hdlc->slot_map;
535
536		if (copy_to_user(ifs->ifs_ifsu.te1, &te1, sizeof(te1)))
537			return -EFAULT;
538		return 0;
539
540	case IF_IFACE_E1:
541	case IF_IFACE_T1:
542		if (!capable(CAP_NET_ADMIN))
543			return -EPERM;
544
545		if (netdev->flags & IFF_UP)
546			return -EBUSY;
547
548		if (copy_from_user(&te1, ifs->ifs_ifsu.te1, sizeof(te1)))
549			return -EFAULT;
550
551		return qmc_hdlc_set_iface(qmc_hdlc, ifs->type, &te1);
552
553	default:
554		return hdlc_ioctl(netdev, ifs);
555	}
556}
557
558static int qmc_hdlc_open(struct net_device *netdev)
559{
560	struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
561	struct qmc_chan_param chan_param;
562	struct qmc_hdlc_desc *desc;
563	int ret;
564	int i;
565
566	ret = qmc_hdlc_framer_start(qmc_hdlc);
567	if (ret)
568		return ret;
569
570	ret = hdlc_open(netdev);
571	if (ret)
572		goto framer_stop;
573
574	/* Update carrier */
575	qmc_hdlc_framer_set_carrier(qmc_hdlc);
576
577	chan_param.mode = QMC_HDLC;
578	/* HDLC_MAX_MRU + 4 for the CRC
579	 * HDLC_MAX_MRU + 4 + 8 for the CRC and some extraspace needed by the QMC
580	 */
581	chan_param.hdlc.max_rx_buf_size = HDLC_MAX_MRU + 4 + 8;
582	chan_param.hdlc.max_rx_frame_size = HDLC_MAX_MRU + 4;
583	chan_param.hdlc.is_crc32 = qmc_hdlc->is_crc32;
584	ret = qmc_chan_set_param(qmc_hdlc->qmc_chan, &chan_param);
585	if (ret) {
586		dev_err(qmc_hdlc->dev, "failed to set param (%d)\n", ret);
587		goto hdlc_close;
588	}
589
590	/* Queue as many recv descriptors as possible */
591	for (i = 0; i < ARRAY_SIZE(qmc_hdlc->rx_descs); i++) {
592		desc = &qmc_hdlc->rx_descs[i];
593
594		desc->netdev = netdev;
595		ret = qmc_hdlc_recv_queue(qmc_hdlc, desc, chan_param.hdlc.max_rx_buf_size);
596		if (ret == -EBUSY && i != 0)
597			break; /* We use all the QMC chan capability */
598		if (ret)
599			goto free_desc;
600	}
601
602	ret = qmc_chan_start(qmc_hdlc->qmc_chan, QMC_CHAN_ALL);
603	if (ret) {
604		dev_err(qmc_hdlc->dev, "qmc chan start failed (%d)\n", ret);
605		goto free_desc;
606	}
607
608	netif_start_queue(netdev);
609
610	return 0;
611
612free_desc:
613	qmc_chan_reset(qmc_hdlc->qmc_chan, QMC_CHAN_ALL);
614	while (i--) {
615		desc = &qmc_hdlc->rx_descs[i];
616		dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size,
617				 DMA_FROM_DEVICE);
618		kfree_skb(desc->skb);
619		desc->skb = NULL;
620	}
621hdlc_close:
622	hdlc_close(netdev);
623framer_stop:
624	qmc_hdlc_framer_stop(qmc_hdlc);
625	return ret;
626}
627
628static int qmc_hdlc_close(struct net_device *netdev)
629{
630	struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
631	struct qmc_hdlc_desc *desc;
632	int i;
633
634	qmc_chan_stop(qmc_hdlc->qmc_chan, QMC_CHAN_ALL);
635	qmc_chan_reset(qmc_hdlc->qmc_chan, QMC_CHAN_ALL);
636
637	netif_stop_queue(netdev);
638
639	for (i = 0; i < ARRAY_SIZE(qmc_hdlc->tx_descs); i++) {
640		desc = &qmc_hdlc->tx_descs[i];
641		if (!desc->skb)
642			continue;
643		dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size,
644				 DMA_TO_DEVICE);
645		kfree_skb(desc->skb);
646		desc->skb = NULL;
647	}
648
649	for (i = 0; i < ARRAY_SIZE(qmc_hdlc->rx_descs); i++) {
650		desc = &qmc_hdlc->rx_descs[i];
651		if (!desc->skb)
652			continue;
653		dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size,
654				 DMA_FROM_DEVICE);
655		kfree_skb(desc->skb);
656		desc->skb = NULL;
657	}
658
659	hdlc_close(netdev);
660	qmc_hdlc_framer_stop(qmc_hdlc);
661	return 0;
662}
663
664static int qmc_hdlc_attach(struct net_device *netdev, unsigned short encoding,
665			   unsigned short parity)
666{
667	struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
668
669	if (encoding != ENCODING_NRZ)
670		return -EINVAL;
671
672	switch (parity) {
673	case PARITY_CRC16_PR1_CCITT:
674		qmc_hdlc->is_crc32 = false;
675		break;
676	case PARITY_CRC32_PR1_CCITT:
677		qmc_hdlc->is_crc32 = true;
678		break;
679	default:
680		dev_err(qmc_hdlc->dev, "unsupported parity %u\n", parity);
681		return -EINVAL;
682	}
683
684	return 0;
685}
686
687static const struct net_device_ops qmc_hdlc_netdev_ops = {
688	.ndo_open       = qmc_hdlc_open,
689	.ndo_stop       = qmc_hdlc_close,
690	.ndo_start_xmit = hdlc_start_xmit,
691	.ndo_siocwandev = qmc_hdlc_ioctl,
692};
693
694static int qmc_hdlc_probe(struct platform_device *pdev)
695{
696	struct device *dev = &pdev->dev;
697	struct qmc_chan_ts_info ts_info;
698	struct qmc_hdlc *qmc_hdlc;
699	struct qmc_chan_info info;
700	hdlc_device *hdlc;
701	int ret;
702
703	qmc_hdlc = devm_kzalloc(dev, sizeof(*qmc_hdlc), GFP_KERNEL);
704	if (!qmc_hdlc)
705		return -ENOMEM;
706
707	qmc_hdlc->dev = dev;
708	spin_lock_init(&qmc_hdlc->tx_lock);
709	spin_lock_init(&qmc_hdlc->carrier_lock);
710
711	qmc_hdlc->qmc_chan = devm_qmc_chan_get_bychild(dev, dev->of_node);
712	if (IS_ERR(qmc_hdlc->qmc_chan))
713		return dev_err_probe(dev, PTR_ERR(qmc_hdlc->qmc_chan),
714				     "get QMC channel failed\n");
715
716	ret = qmc_chan_get_info(qmc_hdlc->qmc_chan, &info);
717	if (ret)
718		return dev_err_probe(dev, ret, "get QMC channel info failed\n");
719
720	if (info.mode != QMC_HDLC)
721		return dev_err_probe(dev, -EINVAL, "QMC chan mode %d is not QMC_HDLC\n",
722				     info.mode);
723
724	ret = qmc_chan_get_ts_info(qmc_hdlc->qmc_chan, &ts_info);
725	if (ret)
726		return dev_err_probe(dev, ret, "get QMC channel ts info failed\n");
727
728	ret = qmc_hdlc_xlate_ts_info(qmc_hdlc, &ts_info, &qmc_hdlc->slot_map);
729	if (ret)
730		return ret;
731
732	qmc_hdlc->framer = devm_framer_optional_get(dev, "fsl,framer");
733	if (IS_ERR(qmc_hdlc->framer))
734		return PTR_ERR(qmc_hdlc->framer);
735
736	ret = qmc_hdlc_framer_init(qmc_hdlc);
737	if (ret)
738		return ret;
739
740	qmc_hdlc->netdev = alloc_hdlcdev(qmc_hdlc);
741	if (!qmc_hdlc->netdev) {
742		ret = -ENOMEM;
743		goto framer_exit;
744	}
745
746	hdlc = dev_to_hdlc(qmc_hdlc->netdev);
747	hdlc->attach = qmc_hdlc_attach;
748	hdlc->xmit = qmc_hdlc_xmit;
749	SET_NETDEV_DEV(qmc_hdlc->netdev, dev);
750	qmc_hdlc->netdev->tx_queue_len = ARRAY_SIZE(qmc_hdlc->tx_descs);
751	qmc_hdlc->netdev->netdev_ops = &qmc_hdlc_netdev_ops;
752	ret = register_hdlc_device(qmc_hdlc->netdev);
753	if (ret) {
754		dev_err_probe(dev, ret, "failed to register hdlc device\n");
755		goto free_netdev;
756	}
757
758	platform_set_drvdata(pdev, qmc_hdlc);
759	return 0;
760
761free_netdev:
762	free_netdev(qmc_hdlc->netdev);
763framer_exit:
764	qmc_hdlc_framer_exit(qmc_hdlc);
765	return ret;
766}
767
768static int qmc_hdlc_remove(struct platform_device *pdev)
769{
770	struct qmc_hdlc *qmc_hdlc = platform_get_drvdata(pdev);
771
772	unregister_hdlc_device(qmc_hdlc->netdev);
773	free_netdev(qmc_hdlc->netdev);
774	qmc_hdlc_framer_exit(qmc_hdlc);
775
776	return 0;
777}
778
779static const struct of_device_id qmc_hdlc_id_table[] = {
780	{ .compatible = "fsl,qmc-hdlc" },
781	{} /* sentinel */
782};
783MODULE_DEVICE_TABLE(of, qmc_hdlc_id_table);
784
785static struct platform_driver qmc_hdlc_driver = {
786	.driver = {
787		.name = "fsl-qmc-hdlc",
788		.of_match_table = qmc_hdlc_id_table,
789	},
790	.probe = qmc_hdlc_probe,
791	.remove = qmc_hdlc_remove,
792};
793module_platform_driver(qmc_hdlc_driver);
794
795MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
796MODULE_DESCRIPTION("QMC HDLC driver");
797MODULE_LICENSE("GPL");