xref: /openbmc/linux/drivers/soc/fsl/qe/qmc.c (revision 745b7908)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * QMC driver
4  *
5  * Copyright 2022 CS GROUP France
6  *
7  * Author: Herve Codina <herve.codina@bootlin.com>
8  */
9 
10 #include <soc/fsl/qe/qmc.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/hdlc.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_platform.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <soc/fsl/cpm.h>
21 #include <sysdev/fsl_soc.h>
22 #include "tsa.h"
23 
24 /* SCC general mode register high (32 bits) */
25 #define SCC_GSMRL	0x00
26 #define SCC_GSMRL_ENR		(1 << 5)
27 #define SCC_GSMRL_ENT		(1 << 4)
28 #define SCC_GSMRL_MODE_QMC	(0x0A << 0)
29 
30 /* SCC general mode register low (32 bits) */
31 #define SCC_GSMRH	0x04
32 #define   SCC_GSMRH_CTSS	(1 << 7)
33 #define   SCC_GSMRH_CDS		(1 << 8)
34 #define   SCC_GSMRH_CTSP	(1 << 9)
35 #define   SCC_GSMRH_CDP		(1 << 10)
36 
37 /* SCC event register (16 bits) */
38 #define SCC_SCCE	0x10
39 #define   SCC_SCCE_IQOV		(1 << 3)
40 #define   SCC_SCCE_GINT		(1 << 2)
41 #define   SCC_SCCE_GUN		(1 << 1)
42 #define   SCC_SCCE_GOV		(1 << 0)
43 
44 /* SCC mask register (16 bits) */
45 #define SCC_SCCM	0x14
46 /* Multichannel base pointer (32 bits) */
47 #define QMC_GBL_MCBASE		0x00
48 /* Multichannel controller state (16 bits) */
49 #define QMC_GBL_QMCSTATE	0x04
50 /* Maximum receive buffer length (16 bits) */
51 #define QMC_GBL_MRBLR		0x06
52 /* Tx time-slot assignment table pointer (16 bits) */
53 #define QMC_GBL_TX_S_PTR	0x08
54 /* Rx pointer (16 bits) */
55 #define QMC_GBL_RXPTR		0x0A
56 /* Global receive frame threshold (16 bits) */
57 #define QMC_GBL_GRFTHR		0x0C
58 /* Global receive frame count (16 bits) */
59 #define QMC_GBL_GRFCNT		0x0E
60 /* Multichannel interrupt base address (32 bits) */
61 #define QMC_GBL_INTBASE		0x10
62 /* Multichannel interrupt pointer (32 bits) */
63 #define QMC_GBL_INTPTR		0x14
64 /* Rx time-slot assignment table pointer (16 bits) */
65 #define QMC_GBL_RX_S_PTR	0x18
66 /* Tx pointer (16 bits) */
67 #define QMC_GBL_TXPTR		0x1A
68 /* CRC constant (32 bits) */
69 #define QMC_GBL_C_MASK32	0x1C
70 /* Time slot assignment table Rx (32 x 16 bits) */
71 #define QMC_GBL_TSATRX		0x20
72 /* Time slot assignment table Tx (32 x 16 bits) */
73 #define QMC_GBL_TSATTX		0x60
74 /* CRC constant (16 bits) */
75 #define QMC_GBL_C_MASK16	0xA0
76 
77 /* TSA entry (16bit entry in TSATRX and TSATTX) */
78 #define QMC_TSA_VALID		(1 << 15)
79 #define QMC_TSA_WRAP		(1 << 14)
80 #define QMC_TSA_MASK		(0x303F)
81 #define QMC_TSA_CHANNEL(x)	((x) << 6)
82 
83 /* Tx buffer descriptor base address (16 bits, offset from MCBASE) */
84 #define QMC_SPE_TBASE	0x00
85 
86 /* Channel mode register (16 bits) */
87 #define QMC_SPE_CHAMR	0x02
88 #define   QMC_SPE_CHAMR_MODE_HDLC	(1 << 15)
89 #define   QMC_SPE_CHAMR_MODE_TRANSP	((0 << 15) | (1 << 13))
90 #define   QMC_SPE_CHAMR_ENT		(1 << 12)
91 #define   QMC_SPE_CHAMR_POL		(1 << 8)
92 #define   QMC_SPE_CHAMR_HDLC_IDLM	(1 << 13)
93 #define   QMC_SPE_CHAMR_HDLC_CRC	(1 << 7)
94 #define   QMC_SPE_CHAMR_HDLC_NOF	(0x0f << 0)
95 #define   QMC_SPE_CHAMR_TRANSP_RD	(1 << 14)
96 #define   QMC_SPE_CHAMR_TRANSP_SYNC	(1 << 10)
97 
98 /* Tx internal state (32 bits) */
99 #define QMC_SPE_TSTATE	0x04
100 /* Tx buffer descriptor pointer (16 bits) */
101 #define QMC_SPE_TBPTR	0x0C
102 /* Zero-insertion state (32 bits) */
103 #define QMC_SPE_ZISTATE	0x14
104 /* Channel’s interrupt mask flags (16 bits) */
105 #define QMC_SPE_INTMSK	0x1C
106 /* Rx buffer descriptor base address (16 bits, offset from MCBASE) */
107 #define QMC_SPE_RBASE	0x20
108 /* HDLC: Maximum frame length register (16 bits) */
109 #define QMC_SPE_MFLR	0x22
110 /* TRANSPARENT: Transparent maximum receive length (16 bits) */
111 #define QMC_SPE_TMRBLR	0x22
112 /* Rx internal state (32 bits) */
113 #define QMC_SPE_RSTATE	0x24
114 /* Rx buffer descriptor pointer (16 bits) */
115 #define QMC_SPE_RBPTR	0x2C
116 /* Packs 4 bytes to 1 long word before writing to buffer (32 bits) */
117 #define QMC_SPE_RPACK	0x30
118 /* Zero deletion state (32 bits) */
119 #define QMC_SPE_ZDSTATE	0x34
120 
121 /* Transparent synchronization (16 bits) */
122 #define QMC_SPE_TRNSYNC 0x3C
123 #define   QMC_SPE_TRNSYNC_RX(x)	((x) << 8)
124 #define   QMC_SPE_TRNSYNC_TX(x)	((x) << 0)
125 
126 /* Interrupt related registers bits */
127 #define QMC_INT_V		(1 << 15)
128 #define QMC_INT_W		(1 << 14)
129 #define QMC_INT_NID		(1 << 13)
130 #define QMC_INT_IDL		(1 << 12)
131 #define QMC_INT_GET_CHANNEL(x)	(((x) & 0x0FC0) >> 6)
132 #define QMC_INT_MRF		(1 << 5)
133 #define QMC_INT_UN		(1 << 4)
134 #define QMC_INT_RXF		(1 << 3)
135 #define QMC_INT_BSY		(1 << 2)
136 #define QMC_INT_TXB		(1 << 1)
137 #define QMC_INT_RXB		(1 << 0)
138 
139 /* BD related registers bits */
140 #define QMC_BD_RX_E	(1 << 15)
141 #define QMC_BD_RX_W	(1 << 13)
142 #define QMC_BD_RX_I	(1 << 12)
143 #define QMC_BD_RX_L	(1 << 11)
144 #define QMC_BD_RX_F	(1 << 10)
145 #define QMC_BD_RX_CM	(1 << 9)
146 #define QMC_BD_RX_UB	(1 << 7)
147 #define QMC_BD_RX_LG	(1 << 5)
148 #define QMC_BD_RX_NO	(1 << 4)
149 #define QMC_BD_RX_AB	(1 << 3)
150 #define QMC_BD_RX_CR	(1 << 2)
151 
152 #define QMC_BD_TX_R	(1 << 15)
153 #define QMC_BD_TX_W	(1 << 13)
154 #define QMC_BD_TX_I	(1 << 12)
155 #define QMC_BD_TX_L	(1 << 11)
156 #define QMC_BD_TX_TC	(1 << 10)
157 #define QMC_BD_TX_CM	(1 << 9)
158 #define QMC_BD_TX_UB	(1 << 7)
159 #define QMC_BD_TX_PAD	(0x0f << 0)
160 
161 /* Numbers of BDs and interrupt items */
162 #define QMC_NB_TXBDS	8
163 #define QMC_NB_RXBDS	8
164 #define QMC_NB_INTS	128
165 
166 struct qmc_xfer_desc {
167 	union {
168 		void (*tx_complete)(void *context);
169 		void (*rx_complete)(void *context, size_t length);
170 	};
171 	void *context;
172 };
173 
174 struct qmc_chan {
175 	struct list_head list;
176 	unsigned int id;
177 	struct qmc *qmc;
178 	void *__iomem s_param;
179 	enum qmc_mode mode;
180 	u64	tx_ts_mask;
181 	u64	rx_ts_mask;
182 	bool is_reverse_data;
183 
184 	spinlock_t	tx_lock;
185 	cbd_t __iomem *txbds;
186 	cbd_t __iomem *txbd_free;
187 	cbd_t __iomem *txbd_done;
188 	struct qmc_xfer_desc tx_desc[QMC_NB_TXBDS];
189 	u64	nb_tx_underrun;
190 	bool	is_tx_stopped;
191 
192 	spinlock_t	rx_lock;
193 	cbd_t __iomem *rxbds;
194 	cbd_t __iomem *rxbd_free;
195 	cbd_t __iomem *rxbd_done;
196 	struct qmc_xfer_desc rx_desc[QMC_NB_RXBDS];
197 	u64	nb_rx_busy;
198 	int	rx_pending;
199 	bool	is_rx_halted;
200 	bool	is_rx_stopped;
201 };
202 
203 struct qmc {
204 	struct device *dev;
205 	struct tsa_serial *tsa_serial;
206 	void *__iomem scc_regs;
207 	void *__iomem scc_pram;
208 	void *__iomem dpram;
209 	u16 scc_pram_offset;
210 	cbd_t __iomem *bd_table;
211 	dma_addr_t bd_dma_addr;
212 	size_t bd_size;
213 	u16 __iomem *int_table;
214 	u16 __iomem *int_curr;
215 	dma_addr_t int_dma_addr;
216 	size_t int_size;
217 	struct list_head chan_head;
218 	struct qmc_chan *chans[64];
219 };
220 
221 static inline void qmc_write16(void *__iomem addr, u16 val)
222 {
223 	iowrite16be(val, addr);
224 }
225 
226 static inline u16 qmc_read16(void *__iomem addr)
227 {
228 	return ioread16be(addr);
229 }
230 
231 static inline void qmc_setbits16(void *__iomem addr, u16 set)
232 {
233 	qmc_write16(addr, qmc_read16(addr) | set);
234 }
235 
236 static inline void qmc_clrbits16(void *__iomem addr, u16 clr)
237 {
238 	qmc_write16(addr, qmc_read16(addr) & ~clr);
239 }
240 
241 static inline void qmc_write32(void *__iomem addr, u32 val)
242 {
243 	iowrite32be(val, addr);
244 }
245 
246 static inline u32 qmc_read32(void *__iomem addr)
247 {
248 	return ioread32be(addr);
249 }
250 
251 static inline void qmc_setbits32(void *__iomem addr, u32 set)
252 {
253 	qmc_write32(addr, qmc_read32(addr) | set);
254 }
255 
256 
257 int qmc_chan_get_info(struct qmc_chan *chan, struct qmc_chan_info *info)
258 {
259 	struct tsa_serial_info tsa_info;
260 	int ret;
261 
262 	/* Retrieve info from the TSA related serial */
263 	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &tsa_info);
264 	if (ret)
265 		return ret;
266 
267 	info->mode = chan->mode;
268 	info->rx_fs_rate = tsa_info.rx_fs_rate;
269 	info->rx_bit_rate = tsa_info.rx_bit_rate;
270 	info->nb_tx_ts = hweight64(chan->tx_ts_mask);
271 	info->tx_fs_rate = tsa_info.tx_fs_rate;
272 	info->tx_bit_rate = tsa_info.tx_bit_rate;
273 	info->nb_rx_ts = hweight64(chan->rx_ts_mask);
274 
275 	return 0;
276 }
277 EXPORT_SYMBOL(qmc_chan_get_info);
278 
279 int qmc_chan_set_param(struct qmc_chan *chan, const struct qmc_chan_param *param)
280 {
281 	if (param->mode != chan->mode)
282 		return -EINVAL;
283 
284 	switch (param->mode) {
285 	case QMC_HDLC:
286 		if ((param->hdlc.max_rx_buf_size % 4) ||
287 		    (param->hdlc.max_rx_buf_size < 8))
288 			return -EINVAL;
289 
290 		qmc_write16(chan->qmc->scc_pram + QMC_GBL_MRBLR,
291 			    param->hdlc.max_rx_buf_size - 8);
292 		qmc_write16(chan->s_param + QMC_SPE_MFLR,
293 			    param->hdlc.max_rx_frame_size);
294 		if (param->hdlc.is_crc32) {
295 			qmc_setbits16(chan->s_param + QMC_SPE_CHAMR,
296 				      QMC_SPE_CHAMR_HDLC_CRC);
297 		} else {
298 			qmc_clrbits16(chan->s_param + QMC_SPE_CHAMR,
299 				      QMC_SPE_CHAMR_HDLC_CRC);
300 		}
301 		break;
302 
303 	case QMC_TRANSPARENT:
304 		qmc_write16(chan->s_param + QMC_SPE_TMRBLR,
305 			    param->transp.max_rx_buf_size);
306 		break;
307 
308 	default:
309 		return -EINVAL;
310 	}
311 
312 	return 0;
313 }
314 EXPORT_SYMBOL(qmc_chan_set_param);
315 
316 int qmc_chan_write_submit(struct qmc_chan *chan, dma_addr_t addr, size_t length,
317 			  void (*complete)(void *context), void *context)
318 {
319 	struct qmc_xfer_desc *xfer_desc;
320 	unsigned long flags;
321 	cbd_t *__iomem bd;
322 	u16 ctrl;
323 	int ret;
324 
325 	/*
326 	 * R bit  UB bit
327 	 *   0       0  : The BD is free
328 	 *   1       1  : The BD is in used, waiting for transfer
329 	 *   0       1  : The BD is in used, waiting for completion
330 	 *   1       0  : Should not append
331 	 */
332 
333 	spin_lock_irqsave(&chan->tx_lock, flags);
334 	bd = chan->txbd_free;
335 
336 	ctrl = qmc_read16(&bd->cbd_sc);
337 	if (ctrl & (QMC_BD_TX_R | QMC_BD_TX_UB)) {
338 		/* We are full ... */
339 		ret = -EBUSY;
340 		goto end;
341 	}
342 
343 	qmc_write16(&bd->cbd_datlen, length);
344 	qmc_write32(&bd->cbd_bufaddr, addr);
345 
346 	xfer_desc = &chan->tx_desc[bd - chan->txbds];
347 	xfer_desc->tx_complete = complete;
348 	xfer_desc->context = context;
349 
350 	/* Activate the descriptor */
351 	ctrl |= (QMC_BD_TX_R | QMC_BD_TX_UB);
352 	wmb(); /* Be sure to flush the descriptor before control update */
353 	qmc_write16(&bd->cbd_sc, ctrl);
354 
355 	if (!chan->is_tx_stopped)
356 		qmc_setbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_POL);
357 
358 	if (ctrl & QMC_BD_TX_W)
359 		chan->txbd_free = chan->txbds;
360 	else
361 		chan->txbd_free++;
362 
363 	ret = 0;
364 
365 end:
366 	spin_unlock_irqrestore(&chan->tx_lock, flags);
367 	return ret;
368 }
369 EXPORT_SYMBOL(qmc_chan_write_submit);
370 
371 static void qmc_chan_write_done(struct qmc_chan *chan)
372 {
373 	struct qmc_xfer_desc *xfer_desc;
374 	void (*complete)(void *context);
375 	unsigned long flags;
376 	void *context;
377 	cbd_t *__iomem bd;
378 	u16 ctrl;
379 
380 	/*
381 	 * R bit  UB bit
382 	 *   0       0  : The BD is free
383 	 *   1       1  : The BD is in used, waiting for transfer
384 	 *   0       1  : The BD is in used, waiting for completion
385 	 *   1       0  : Should not append
386 	 */
387 
388 	spin_lock_irqsave(&chan->tx_lock, flags);
389 	bd = chan->txbd_done;
390 
391 	ctrl = qmc_read16(&bd->cbd_sc);
392 	while (!(ctrl & QMC_BD_TX_R)) {
393 		if (!(ctrl & QMC_BD_TX_UB))
394 			goto end;
395 
396 		xfer_desc = &chan->tx_desc[bd - chan->txbds];
397 		complete = xfer_desc->tx_complete;
398 		context = xfer_desc->context;
399 		xfer_desc->tx_complete = NULL;
400 		xfer_desc->context = NULL;
401 
402 		qmc_write16(&bd->cbd_sc, ctrl & ~QMC_BD_TX_UB);
403 
404 		if (ctrl & QMC_BD_TX_W)
405 			chan->txbd_done = chan->txbds;
406 		else
407 			chan->txbd_done++;
408 
409 		if (complete) {
410 			spin_unlock_irqrestore(&chan->tx_lock, flags);
411 			complete(context);
412 			spin_lock_irqsave(&chan->tx_lock, flags);
413 		}
414 
415 		bd = chan->txbd_done;
416 		ctrl = qmc_read16(&bd->cbd_sc);
417 	}
418 
419 end:
420 	spin_unlock_irqrestore(&chan->tx_lock, flags);
421 }
422 
423 int qmc_chan_read_submit(struct qmc_chan *chan, dma_addr_t addr, size_t length,
424 			 void (*complete)(void *context, size_t length), void *context)
425 {
426 	struct qmc_xfer_desc *xfer_desc;
427 	unsigned long flags;
428 	cbd_t *__iomem bd;
429 	u16 ctrl;
430 	int ret;
431 
432 	/*
433 	 * E bit  UB bit
434 	 *   0       0  : The BD is free
435 	 *   1       1  : The BD is in used, waiting for transfer
436 	 *   0       1  : The BD is in used, waiting for completion
437 	 *   1       0  : Should not append
438 	 */
439 
440 	spin_lock_irqsave(&chan->rx_lock, flags);
441 	bd = chan->rxbd_free;
442 
443 	ctrl = qmc_read16(&bd->cbd_sc);
444 	if (ctrl & (QMC_BD_RX_E | QMC_BD_RX_UB)) {
445 		/* We are full ... */
446 		ret = -EBUSY;
447 		goto end;
448 	}
449 
450 	qmc_write16(&bd->cbd_datlen, 0); /* data length is updated by the QMC */
451 	qmc_write32(&bd->cbd_bufaddr, addr);
452 
453 	xfer_desc = &chan->rx_desc[bd - chan->rxbds];
454 	xfer_desc->rx_complete = complete;
455 	xfer_desc->context = context;
456 
457 	/* Activate the descriptor */
458 	ctrl |= (QMC_BD_RX_E | QMC_BD_RX_UB);
459 	wmb(); /* Be sure to flush data before descriptor activation */
460 	qmc_write16(&bd->cbd_sc, ctrl);
461 
462 	/* Restart receiver if needed */
463 	if (chan->is_rx_halted && !chan->is_rx_stopped) {
464 		/* Restart receiver */
465 		if (chan->mode == QMC_TRANSPARENT)
466 			qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x18000080);
467 		else
468 			qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x00000080);
469 		qmc_write32(chan->s_param + QMC_SPE_RSTATE, 0x31000000);
470 		chan->is_rx_halted = false;
471 	}
472 	chan->rx_pending++;
473 
474 	if (ctrl & QMC_BD_RX_W)
475 		chan->rxbd_free = chan->rxbds;
476 	else
477 		chan->rxbd_free++;
478 
479 	ret = 0;
480 end:
481 	spin_unlock_irqrestore(&chan->rx_lock, flags);
482 	return ret;
483 }
484 EXPORT_SYMBOL(qmc_chan_read_submit);
485 
486 static void qmc_chan_read_done(struct qmc_chan *chan)
487 {
488 	void (*complete)(void *context, size_t size);
489 	struct qmc_xfer_desc *xfer_desc;
490 	unsigned long flags;
491 	cbd_t *__iomem bd;
492 	void *context;
493 	u16 datalen;
494 	u16 ctrl;
495 
496 	/*
497 	 * E bit  UB bit
498 	 *   0       0  : The BD is free
499 	 *   1       1  : The BD is in used, waiting for transfer
500 	 *   0       1  : The BD is in used, waiting for completion
501 	 *   1       0  : Should not append
502 	 */
503 
504 	spin_lock_irqsave(&chan->rx_lock, flags);
505 	bd = chan->rxbd_done;
506 
507 	ctrl = qmc_read16(&bd->cbd_sc);
508 	while (!(ctrl & QMC_BD_RX_E)) {
509 		if (!(ctrl & QMC_BD_RX_UB))
510 			goto end;
511 
512 		xfer_desc = &chan->rx_desc[bd - chan->rxbds];
513 		complete = xfer_desc->rx_complete;
514 		context = xfer_desc->context;
515 		xfer_desc->rx_complete = NULL;
516 		xfer_desc->context = NULL;
517 
518 		datalen = qmc_read16(&bd->cbd_datlen);
519 		qmc_write16(&bd->cbd_sc, ctrl & ~QMC_BD_RX_UB);
520 
521 		if (ctrl & QMC_BD_RX_W)
522 			chan->rxbd_done = chan->rxbds;
523 		else
524 			chan->rxbd_done++;
525 
526 		chan->rx_pending--;
527 
528 		if (complete) {
529 			spin_unlock_irqrestore(&chan->rx_lock, flags);
530 			complete(context, datalen);
531 			spin_lock_irqsave(&chan->rx_lock, flags);
532 		}
533 
534 		bd = chan->rxbd_done;
535 		ctrl = qmc_read16(&bd->cbd_sc);
536 	}
537 
538 end:
539 	spin_unlock_irqrestore(&chan->rx_lock, flags);
540 }
541 
542 static int qmc_chan_command(struct qmc_chan *chan, u8 qmc_opcode)
543 {
544 	return cpm_command(chan->id << 2, (qmc_opcode << 4) | 0x0E);
545 }
546 
547 static int qmc_chan_stop_rx(struct qmc_chan *chan)
548 {
549 	unsigned long flags;
550 	int ret;
551 
552 	spin_lock_irqsave(&chan->rx_lock, flags);
553 
554 	/* Send STOP RECEIVE command */
555 	ret = qmc_chan_command(chan, 0x0);
556 	if (ret) {
557 		dev_err(chan->qmc->dev, "chan %u: Send STOP RECEIVE failed (%d)\n",
558 			chan->id, ret);
559 		goto end;
560 	}
561 
562 	chan->is_rx_stopped = true;
563 
564 end:
565 	spin_unlock_irqrestore(&chan->rx_lock, flags);
566 	return ret;
567 }
568 
569 static int qmc_chan_stop_tx(struct qmc_chan *chan)
570 {
571 	unsigned long flags;
572 	int ret;
573 
574 	spin_lock_irqsave(&chan->tx_lock, flags);
575 
576 	/* Send STOP TRANSMIT command */
577 	ret = qmc_chan_command(chan, 0x1);
578 	if (ret) {
579 		dev_err(chan->qmc->dev, "chan %u: Send STOP TRANSMIT failed (%d)\n",
580 			chan->id, ret);
581 		goto end;
582 	}
583 
584 	chan->is_tx_stopped = true;
585 
586 end:
587 	spin_unlock_irqrestore(&chan->tx_lock, flags);
588 	return ret;
589 }
590 
591 int qmc_chan_stop(struct qmc_chan *chan, int direction)
592 {
593 	int ret;
594 
595 	if (direction & QMC_CHAN_READ) {
596 		ret = qmc_chan_stop_rx(chan);
597 		if (ret)
598 			return ret;
599 	}
600 
601 	if (direction & QMC_CHAN_WRITE) {
602 		ret = qmc_chan_stop_tx(chan);
603 		if (ret)
604 			return ret;
605 	}
606 
607 	return 0;
608 }
609 EXPORT_SYMBOL(qmc_chan_stop);
610 
611 static void qmc_chan_start_rx(struct qmc_chan *chan)
612 {
613 	unsigned long flags;
614 
615 	spin_lock_irqsave(&chan->rx_lock, flags);
616 
617 	/* Restart the receiver */
618 	if (chan->mode == QMC_TRANSPARENT)
619 		qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x18000080);
620 	else
621 		qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x00000080);
622 	qmc_write32(chan->s_param + QMC_SPE_RSTATE, 0x31000000);
623 	chan->is_rx_halted = false;
624 
625 	chan->is_rx_stopped = false;
626 
627 	spin_unlock_irqrestore(&chan->rx_lock, flags);
628 }
629 
630 static void qmc_chan_start_tx(struct qmc_chan *chan)
631 {
632 	unsigned long flags;
633 
634 	spin_lock_irqsave(&chan->tx_lock, flags);
635 
636 	/*
637 	 * Enable channel transmitter as it could be disabled if
638 	 * qmc_chan_reset() was called.
639 	 */
640 	qmc_setbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_ENT);
641 
642 	/* Set the POL bit in the channel mode register */
643 	qmc_setbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_POL);
644 
645 	chan->is_tx_stopped = false;
646 
647 	spin_unlock_irqrestore(&chan->tx_lock, flags);
648 }
649 
650 int qmc_chan_start(struct qmc_chan *chan, int direction)
651 {
652 	if (direction & QMC_CHAN_READ)
653 		qmc_chan_start_rx(chan);
654 
655 	if (direction & QMC_CHAN_WRITE)
656 		qmc_chan_start_tx(chan);
657 
658 	return 0;
659 }
660 EXPORT_SYMBOL(qmc_chan_start);
661 
662 static void qmc_chan_reset_rx(struct qmc_chan *chan)
663 {
664 	struct qmc_xfer_desc *xfer_desc;
665 	unsigned long flags;
666 	cbd_t *__iomem bd;
667 	u16 ctrl;
668 
669 	spin_lock_irqsave(&chan->rx_lock, flags);
670 	bd = chan->rxbds;
671 	do {
672 		ctrl = qmc_read16(&bd->cbd_sc);
673 		qmc_write16(&bd->cbd_sc, ctrl & ~(QMC_BD_RX_UB | QMC_BD_RX_E));
674 
675 		xfer_desc = &chan->rx_desc[bd - chan->rxbds];
676 		xfer_desc->rx_complete = NULL;
677 		xfer_desc->context = NULL;
678 
679 		bd++;
680 	} while (!(ctrl & QMC_BD_RX_W));
681 
682 	chan->rxbd_free = chan->rxbds;
683 	chan->rxbd_done = chan->rxbds;
684 	qmc_write16(chan->s_param + QMC_SPE_RBPTR,
685 		    qmc_read16(chan->s_param + QMC_SPE_RBASE));
686 
687 	chan->rx_pending = 0;
688 	chan->is_rx_stopped = false;
689 
690 	spin_unlock_irqrestore(&chan->rx_lock, flags);
691 }
692 
693 static void qmc_chan_reset_tx(struct qmc_chan *chan)
694 {
695 	struct qmc_xfer_desc *xfer_desc;
696 	unsigned long flags;
697 	cbd_t *__iomem bd;
698 	u16 ctrl;
699 
700 	spin_lock_irqsave(&chan->tx_lock, flags);
701 
702 	/* Disable transmitter. It will be re-enable on qmc_chan_start() */
703 	qmc_clrbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_ENT);
704 
705 	bd = chan->txbds;
706 	do {
707 		ctrl = qmc_read16(&bd->cbd_sc);
708 		qmc_write16(&bd->cbd_sc, ctrl & ~(QMC_BD_TX_UB | QMC_BD_TX_R));
709 
710 		xfer_desc = &chan->tx_desc[bd - chan->txbds];
711 		xfer_desc->tx_complete = NULL;
712 		xfer_desc->context = NULL;
713 
714 		bd++;
715 	} while (!(ctrl & QMC_BD_TX_W));
716 
717 	chan->txbd_free = chan->txbds;
718 	chan->txbd_done = chan->txbds;
719 	qmc_write16(chan->s_param + QMC_SPE_TBPTR,
720 		    qmc_read16(chan->s_param + QMC_SPE_TBASE));
721 
722 	/* Reset TSTATE and ZISTATE to their initial value */
723 	qmc_write32(chan->s_param + QMC_SPE_TSTATE, 0x30000000);
724 	qmc_write32(chan->s_param + QMC_SPE_ZISTATE, 0x00000100);
725 
726 	spin_unlock_irqrestore(&chan->tx_lock, flags);
727 }
728 
729 int qmc_chan_reset(struct qmc_chan *chan, int direction)
730 {
731 	if (direction & QMC_CHAN_READ)
732 		qmc_chan_reset_rx(chan);
733 
734 	if (direction & QMC_CHAN_WRITE)
735 		qmc_chan_reset_tx(chan);
736 
737 	return 0;
738 }
739 EXPORT_SYMBOL(qmc_chan_reset);
740 
741 static int qmc_check_chans(struct qmc *qmc)
742 {
743 	struct tsa_serial_info info;
744 	bool is_one_table = false;
745 	struct qmc_chan *chan;
746 	u64 tx_ts_mask = 0;
747 	u64 rx_ts_mask = 0;
748 	u64 tx_ts_assigned_mask;
749 	u64 rx_ts_assigned_mask;
750 	int ret;
751 
752 	/* Retrieve info from the TSA related serial */
753 	ret = tsa_serial_get_info(qmc->tsa_serial, &info);
754 	if (ret)
755 		return ret;
756 
757 	if ((info.nb_tx_ts > 64) || (info.nb_rx_ts > 64)) {
758 		dev_err(qmc->dev, "Number of TSA Tx/Rx TS assigned not supported\n");
759 		return -EINVAL;
760 	}
761 
762 	/*
763 	 * If more than 32 TS are assigned to this serial, one common table is
764 	 * used for Tx and Rx and so masks must be equal for all channels.
765 	 */
766 	if ((info.nb_tx_ts > 32) || (info.nb_rx_ts > 32)) {
767 		if (info.nb_tx_ts != info.nb_rx_ts) {
768 			dev_err(qmc->dev, "Number of TSA Tx/Rx TS assigned are not equal\n");
769 			return -EINVAL;
770 		}
771 		is_one_table = true;
772 	}
773 
774 	tx_ts_assigned_mask = info.nb_tx_ts == 64 ? U64_MAX : (((u64)1) << info.nb_tx_ts) - 1;
775 	rx_ts_assigned_mask = info.nb_rx_ts == 64 ? U64_MAX : (((u64)1) << info.nb_rx_ts) - 1;
776 
777 	list_for_each_entry(chan, &qmc->chan_head, list) {
778 		if (chan->tx_ts_mask > tx_ts_assigned_mask) {
779 			dev_err(qmc->dev, "chan %u uses TSA unassigned Tx TS\n", chan->id);
780 			return -EINVAL;
781 		}
782 		if (tx_ts_mask & chan->tx_ts_mask) {
783 			dev_err(qmc->dev, "chan %u uses an already used Tx TS\n", chan->id);
784 			return -EINVAL;
785 		}
786 
787 		if (chan->rx_ts_mask > rx_ts_assigned_mask) {
788 			dev_err(qmc->dev, "chan %u uses TSA unassigned Rx TS\n", chan->id);
789 			return -EINVAL;
790 		}
791 		if (rx_ts_mask & chan->rx_ts_mask) {
792 			dev_err(qmc->dev, "chan %u uses an already used Rx TS\n", chan->id);
793 			return -EINVAL;
794 		}
795 
796 		if (is_one_table && (chan->tx_ts_mask != chan->rx_ts_mask)) {
797 			dev_err(qmc->dev, "chan %u uses different Rx and Tx TS\n", chan->id);
798 			return -EINVAL;
799 		}
800 
801 		tx_ts_mask |= chan->tx_ts_mask;
802 		rx_ts_mask |= chan->rx_ts_mask;
803 	}
804 
805 	return 0;
806 }
807 
808 static unsigned int qmc_nb_chans(struct qmc *qmc)
809 {
810 	unsigned int count = 0;
811 	struct qmc_chan *chan;
812 
813 	list_for_each_entry(chan, &qmc->chan_head, list)
814 		count++;
815 
816 	return count;
817 }
818 
819 static int qmc_of_parse_chans(struct qmc *qmc, struct device_node *np)
820 {
821 	struct device_node *chan_np;
822 	struct qmc_chan *chan;
823 	const char *mode;
824 	u32 chan_id;
825 	u64 ts_mask;
826 	int ret;
827 
828 	for_each_available_child_of_node(np, chan_np) {
829 		ret = of_property_read_u32(chan_np, "reg", &chan_id);
830 		if (ret) {
831 			dev_err(qmc->dev, "%pOF: failed to read reg\n", chan_np);
832 			of_node_put(chan_np);
833 			return ret;
834 		}
835 		if (chan_id > 63) {
836 			dev_err(qmc->dev, "%pOF: Invalid chan_id\n", chan_np);
837 			of_node_put(chan_np);
838 			return -EINVAL;
839 		}
840 
841 		chan = devm_kzalloc(qmc->dev, sizeof(*chan), GFP_KERNEL);
842 		if (!chan) {
843 			of_node_put(chan_np);
844 			return -ENOMEM;
845 		}
846 
847 		chan->id = chan_id;
848 		spin_lock_init(&chan->rx_lock);
849 		spin_lock_init(&chan->tx_lock);
850 
851 		ret = of_property_read_u64(chan_np, "fsl,tx-ts-mask", &ts_mask);
852 		if (ret) {
853 			dev_err(qmc->dev, "%pOF: failed to read fsl,tx-ts-mask\n",
854 				chan_np);
855 			of_node_put(chan_np);
856 			return ret;
857 		}
858 		chan->tx_ts_mask = ts_mask;
859 
860 		ret = of_property_read_u64(chan_np, "fsl,rx-ts-mask", &ts_mask);
861 		if (ret) {
862 			dev_err(qmc->dev, "%pOF: failed to read fsl,rx-ts-mask\n",
863 				chan_np);
864 			of_node_put(chan_np);
865 			return ret;
866 		}
867 		chan->rx_ts_mask = ts_mask;
868 
869 		mode = "transparent";
870 		ret = of_property_read_string(chan_np, "fsl,operational-mode", &mode);
871 		if (ret && ret != -EINVAL) {
872 			dev_err(qmc->dev, "%pOF: failed to read fsl,operational-mode\n",
873 				chan_np);
874 			of_node_put(chan_np);
875 			return ret;
876 		}
877 		if (!strcmp(mode, "transparent")) {
878 			chan->mode = QMC_TRANSPARENT;
879 		} else if (!strcmp(mode, "hdlc")) {
880 			chan->mode = QMC_HDLC;
881 		} else {
882 			dev_err(qmc->dev, "%pOF: Invalid fsl,operational-mode (%s)\n",
883 				chan_np, mode);
884 			of_node_put(chan_np);
885 			return -EINVAL;
886 		}
887 
888 		chan->is_reverse_data = of_property_read_bool(chan_np,
889 							      "fsl,reverse-data");
890 
891 		list_add_tail(&chan->list, &qmc->chan_head);
892 		qmc->chans[chan->id] = chan;
893 	}
894 
895 	return qmc_check_chans(qmc);
896 }
897 
898 static int qmc_setup_tsa_64rxtx(struct qmc *qmc, const struct tsa_serial_info *info)
899 {
900 	struct qmc_chan *chan;
901 	unsigned int i;
902 	u16 val;
903 
904 	/*
905 	 * Use a common Tx/Rx 64 entries table.
906 	 * Everything was previously checked, Tx and Rx related stuffs are
907 	 * identical -> Used Rx related stuff to build the table
908 	 */
909 
910 	/* Invalidate all entries */
911 	for (i = 0; i < 64; i++)
912 		qmc_write16(qmc->scc_pram + QMC_GBL_TSATRX + (i * 2), 0x0000);
913 
914 	/* Set entries based on Rx stuff*/
915 	list_for_each_entry(chan, &qmc->chan_head, list) {
916 		for (i = 0; i < info->nb_rx_ts; i++) {
917 			if (!(chan->rx_ts_mask & (((u64)1) << i)))
918 				continue;
919 
920 			val = QMC_TSA_VALID | QMC_TSA_MASK |
921 			      QMC_TSA_CHANNEL(chan->id);
922 			qmc_write16(qmc->scc_pram + QMC_GBL_TSATRX + (i * 2), val);
923 		}
924 	}
925 
926 	/* Set Wrap bit on last entry */
927 	qmc_setbits16(qmc->scc_pram + QMC_GBL_TSATRX + ((info->nb_rx_ts - 1) * 2),
928 		      QMC_TSA_WRAP);
929 
930 	/* Init pointers to the table */
931 	val = qmc->scc_pram_offset + QMC_GBL_TSATRX;
932 	qmc_write16(qmc->scc_pram + QMC_GBL_RX_S_PTR, val);
933 	qmc_write16(qmc->scc_pram + QMC_GBL_RXPTR, val);
934 	qmc_write16(qmc->scc_pram + QMC_GBL_TX_S_PTR, val);
935 	qmc_write16(qmc->scc_pram + QMC_GBL_TXPTR, val);
936 
937 	return 0;
938 }
939 
940 static int qmc_setup_tsa_32rx_32tx(struct qmc *qmc, const struct tsa_serial_info *info)
941 {
942 	struct qmc_chan *chan;
943 	unsigned int i;
944 	u16 val;
945 
946 	/*
947 	 * Use a Tx 32 entries table and a Rx 32 entries table.
948 	 * Everything was previously checked.
949 	 */
950 
951 	/* Invalidate all entries */
952 	for (i = 0; i < 32; i++) {
953 		qmc_write16(qmc->scc_pram + QMC_GBL_TSATRX + (i * 2), 0x0000);
954 		qmc_write16(qmc->scc_pram + QMC_GBL_TSATTX + (i * 2), 0x0000);
955 	}
956 
957 	/* Set entries based on Rx and Tx stuff*/
958 	list_for_each_entry(chan, &qmc->chan_head, list) {
959 		/* Rx part */
960 		for (i = 0; i < info->nb_rx_ts; i++) {
961 			if (!(chan->rx_ts_mask & (((u64)1) << i)))
962 				continue;
963 
964 			val = QMC_TSA_VALID | QMC_TSA_MASK |
965 			      QMC_TSA_CHANNEL(chan->id);
966 			qmc_write16(qmc->scc_pram + QMC_GBL_TSATRX + (i * 2), val);
967 		}
968 		/* Tx part */
969 		for (i = 0; i < info->nb_tx_ts; i++) {
970 			if (!(chan->tx_ts_mask & (((u64)1) << i)))
971 				continue;
972 
973 			val = QMC_TSA_VALID | QMC_TSA_MASK |
974 			      QMC_TSA_CHANNEL(chan->id);
975 			qmc_write16(qmc->scc_pram + QMC_GBL_TSATTX + (i * 2), val);
976 		}
977 	}
978 
979 	/* Set Wrap bit on last entries */
980 	qmc_setbits16(qmc->scc_pram + QMC_GBL_TSATRX + ((info->nb_rx_ts - 1) * 2),
981 		      QMC_TSA_WRAP);
982 	qmc_setbits16(qmc->scc_pram + QMC_GBL_TSATTX + ((info->nb_tx_ts - 1) * 2),
983 		      QMC_TSA_WRAP);
984 
985 	/* Init Rx pointers ...*/
986 	val = qmc->scc_pram_offset + QMC_GBL_TSATRX;
987 	qmc_write16(qmc->scc_pram + QMC_GBL_RX_S_PTR, val);
988 	qmc_write16(qmc->scc_pram + QMC_GBL_RXPTR, val);
989 
990 	/* ... and Tx pointers */
991 	val = qmc->scc_pram_offset + QMC_GBL_TSATTX;
992 	qmc_write16(qmc->scc_pram + QMC_GBL_TX_S_PTR, val);
993 	qmc_write16(qmc->scc_pram + QMC_GBL_TXPTR, val);
994 
995 	return 0;
996 }
997 
998 static int qmc_setup_tsa(struct qmc *qmc)
999 {
1000 	struct tsa_serial_info info;
1001 	int ret;
1002 
1003 	/* Retrieve info from the TSA related serial */
1004 	ret = tsa_serial_get_info(qmc->tsa_serial, &info);
1005 	if (ret)
1006 		return ret;
1007 
1008 	/*
1009 	 * Setup one common 64 entries table or two 32 entries (one for Tx and
1010 	 * one for Tx) according to assigned TS numbers.
1011 	 */
1012 	return ((info.nb_tx_ts > 32) || (info.nb_rx_ts > 32)) ?
1013 		qmc_setup_tsa_64rxtx(qmc, &info) :
1014 		qmc_setup_tsa_32rx_32tx(qmc, &info);
1015 }
1016 
1017 static int qmc_setup_chan_trnsync(struct qmc *qmc, struct qmc_chan *chan)
1018 {
1019 	struct tsa_serial_info info;
1020 	u16 first_rx, last_tx;
1021 	u16 trnsync;
1022 	int ret;
1023 
1024 	/* Retrieve info from the TSA related serial */
1025 	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &info);
1026 	if (ret)
1027 		return ret;
1028 
1029 	/* Find the first Rx TS allocated to the channel */
1030 	first_rx = chan->rx_ts_mask ? __ffs64(chan->rx_ts_mask) + 1 : 0;
1031 
1032 	/* Find the last Tx TS allocated to the channel */
1033 	last_tx = fls64(chan->tx_ts_mask);
1034 
1035 	trnsync = 0;
1036 	if (info.nb_rx_ts)
1037 		trnsync |= QMC_SPE_TRNSYNC_RX((first_rx % info.nb_rx_ts) * 2);
1038 	if (info.nb_tx_ts)
1039 		trnsync |= QMC_SPE_TRNSYNC_TX((last_tx % info.nb_tx_ts) * 2);
1040 
1041 	qmc_write16(chan->s_param + QMC_SPE_TRNSYNC, trnsync);
1042 
1043 	dev_dbg(qmc->dev, "chan %u: trnsync=0x%04x, rx %u/%u 0x%llx, tx %u/%u 0x%llx\n",
1044 		chan->id, trnsync,
1045 		first_rx, info.nb_rx_ts, chan->rx_ts_mask,
1046 		last_tx, info.nb_tx_ts, chan->tx_ts_mask);
1047 
1048 	return 0;
1049 }
1050 
1051 static int qmc_setup_chan(struct qmc *qmc, struct qmc_chan *chan)
1052 {
1053 	unsigned int i;
1054 	cbd_t __iomem *bd;
1055 	int ret;
1056 	u16 val;
1057 
1058 	chan->qmc = qmc;
1059 
1060 	/* Set channel specific parameter base address */
1061 	chan->s_param = qmc->dpram + (chan->id * 64);
1062 	/* 16 bd per channel (8 rx and 8 tx) */
1063 	chan->txbds = qmc->bd_table + (chan->id * (QMC_NB_TXBDS + QMC_NB_RXBDS));
1064 	chan->rxbds = qmc->bd_table + (chan->id * (QMC_NB_TXBDS + QMC_NB_RXBDS)) + QMC_NB_TXBDS;
1065 
1066 	chan->txbd_free = chan->txbds;
1067 	chan->txbd_done = chan->txbds;
1068 	chan->rxbd_free = chan->rxbds;
1069 	chan->rxbd_done = chan->rxbds;
1070 
1071 	/* TBASE and TBPTR*/
1072 	val = chan->id * (QMC_NB_TXBDS + QMC_NB_RXBDS) * sizeof(cbd_t);
1073 	qmc_write16(chan->s_param + QMC_SPE_TBASE, val);
1074 	qmc_write16(chan->s_param + QMC_SPE_TBPTR, val);
1075 
1076 	/* RBASE and RBPTR*/
1077 	val = ((chan->id * (QMC_NB_TXBDS + QMC_NB_RXBDS)) + QMC_NB_TXBDS) * sizeof(cbd_t);
1078 	qmc_write16(chan->s_param + QMC_SPE_RBASE, val);
1079 	qmc_write16(chan->s_param + QMC_SPE_RBPTR, val);
1080 	qmc_write32(chan->s_param + QMC_SPE_TSTATE, 0x30000000);
1081 	qmc_write32(chan->s_param + QMC_SPE_RSTATE, 0x31000000);
1082 	qmc_write32(chan->s_param + QMC_SPE_ZISTATE, 0x00000100);
1083 	if (chan->mode == QMC_TRANSPARENT) {
1084 		qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x18000080);
1085 		qmc_write16(chan->s_param + QMC_SPE_TMRBLR, 60);
1086 		val = QMC_SPE_CHAMR_MODE_TRANSP | QMC_SPE_CHAMR_TRANSP_SYNC;
1087 		if (chan->is_reverse_data)
1088 			val |= QMC_SPE_CHAMR_TRANSP_RD;
1089 		qmc_write16(chan->s_param + QMC_SPE_CHAMR, val);
1090 		ret = qmc_setup_chan_trnsync(qmc, chan);
1091 		if (ret)
1092 			return ret;
1093 	} else {
1094 		qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x00000080);
1095 		qmc_write16(chan->s_param + QMC_SPE_MFLR, 60);
1096 		qmc_write16(chan->s_param + QMC_SPE_CHAMR,
1097 			QMC_SPE_CHAMR_MODE_HDLC | QMC_SPE_CHAMR_HDLC_IDLM);
1098 	}
1099 
1100 	/* Do not enable interrupts now. They will be enabled later */
1101 	qmc_write16(chan->s_param + QMC_SPE_INTMSK, 0x0000);
1102 
1103 	/* Init Rx BDs and set Wrap bit on last descriptor */
1104 	BUILD_BUG_ON(QMC_NB_RXBDS == 0);
1105 	val = QMC_BD_RX_I;
1106 	for (i = 0; i < QMC_NB_RXBDS; i++) {
1107 		bd = chan->rxbds + i;
1108 		qmc_write16(&bd->cbd_sc, val);
1109 	}
1110 	bd = chan->rxbds + QMC_NB_RXBDS - 1;
1111 	qmc_write16(&bd->cbd_sc, val | QMC_BD_RX_W);
1112 
1113 	/* Init Tx BDs and set Wrap bit on last descriptor */
1114 	BUILD_BUG_ON(QMC_NB_TXBDS == 0);
1115 	val = QMC_BD_TX_I;
1116 	if (chan->mode == QMC_HDLC)
1117 		val |= QMC_BD_TX_L | QMC_BD_TX_TC;
1118 	for (i = 0; i < QMC_NB_TXBDS; i++) {
1119 		bd = chan->txbds + i;
1120 		qmc_write16(&bd->cbd_sc, val);
1121 	}
1122 	bd = chan->txbds + QMC_NB_TXBDS - 1;
1123 	qmc_write16(&bd->cbd_sc, val | QMC_BD_TX_W);
1124 
1125 	return 0;
1126 }
1127 
1128 static int qmc_setup_chans(struct qmc *qmc)
1129 {
1130 	struct qmc_chan *chan;
1131 	int ret;
1132 
1133 	list_for_each_entry(chan, &qmc->chan_head, list) {
1134 		ret = qmc_setup_chan(qmc, chan);
1135 		if (ret)
1136 			return ret;
1137 	}
1138 
1139 	return 0;
1140 }
1141 
1142 static int qmc_finalize_chans(struct qmc *qmc)
1143 {
1144 	struct qmc_chan *chan;
1145 	int ret;
1146 
1147 	list_for_each_entry(chan, &qmc->chan_head, list) {
1148 		/* Unmask channel interrupts */
1149 		if (chan->mode == QMC_HDLC) {
1150 			qmc_write16(chan->s_param + QMC_SPE_INTMSK,
1151 				    QMC_INT_NID | QMC_INT_IDL | QMC_INT_MRF |
1152 				    QMC_INT_UN | QMC_INT_RXF | QMC_INT_BSY |
1153 				    QMC_INT_TXB | QMC_INT_RXB);
1154 		} else {
1155 			qmc_write16(chan->s_param + QMC_SPE_INTMSK,
1156 				    QMC_INT_UN | QMC_INT_BSY |
1157 				    QMC_INT_TXB | QMC_INT_RXB);
1158 		}
1159 
1160 		/* Forced stop the channel */
1161 		ret = qmc_chan_stop(chan, QMC_CHAN_ALL);
1162 		if (ret)
1163 			return ret;
1164 	}
1165 
1166 	return 0;
1167 }
1168 
1169 static int qmc_setup_ints(struct qmc *qmc)
1170 {
1171 	unsigned int i;
1172 	u16 __iomem *last;
1173 
1174 	/* Raz all entries */
1175 	for (i = 0; i < (qmc->int_size / sizeof(u16)); i++)
1176 		qmc_write16(qmc->int_table + i, 0x0000);
1177 
1178 	/* Set Wrap bit on last entry */
1179 	if (qmc->int_size >= sizeof(u16)) {
1180 		last = qmc->int_table + (qmc->int_size / sizeof(u16)) - 1;
1181 		qmc_write16(last, QMC_INT_W);
1182 	}
1183 
1184 	return 0;
1185 }
1186 
1187 static void qmc_irq_gint(struct qmc *qmc)
1188 {
1189 	struct qmc_chan *chan;
1190 	unsigned int chan_id;
1191 	unsigned long flags;
1192 	u16 int_entry;
1193 
1194 	int_entry = qmc_read16(qmc->int_curr);
1195 	while (int_entry & QMC_INT_V) {
1196 		/* Clear all but the Wrap bit */
1197 		qmc_write16(qmc->int_curr, int_entry & QMC_INT_W);
1198 
1199 		chan_id = QMC_INT_GET_CHANNEL(int_entry);
1200 		chan = qmc->chans[chan_id];
1201 		if (!chan) {
1202 			dev_err(qmc->dev, "interrupt on invalid chan %u\n", chan_id);
1203 			goto int_next;
1204 		}
1205 
1206 		if (int_entry & QMC_INT_TXB)
1207 			qmc_chan_write_done(chan);
1208 
1209 		if (int_entry & QMC_INT_UN) {
1210 			dev_info(qmc->dev, "intr chan %u, 0x%04x (UN)\n", chan_id,
1211 				 int_entry);
1212 			chan->nb_tx_underrun++;
1213 		}
1214 
1215 		if (int_entry & QMC_INT_BSY) {
1216 			dev_info(qmc->dev, "intr chan %u, 0x%04x (BSY)\n", chan_id,
1217 				 int_entry);
1218 			chan->nb_rx_busy++;
1219 			/* Restart the receiver if needed */
1220 			spin_lock_irqsave(&chan->rx_lock, flags);
1221 			if (chan->rx_pending && !chan->is_rx_stopped) {
1222 				if (chan->mode == QMC_TRANSPARENT)
1223 					qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x18000080);
1224 				else
1225 					qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, 0x00000080);
1226 				qmc_write32(chan->s_param + QMC_SPE_RSTATE, 0x31000000);
1227 				chan->is_rx_halted = false;
1228 			} else {
1229 				chan->is_rx_halted = true;
1230 			}
1231 			spin_unlock_irqrestore(&chan->rx_lock, flags);
1232 		}
1233 
1234 		if (int_entry & QMC_INT_RXB)
1235 			qmc_chan_read_done(chan);
1236 
1237 int_next:
1238 		if (int_entry & QMC_INT_W)
1239 			qmc->int_curr = qmc->int_table;
1240 		else
1241 			qmc->int_curr++;
1242 		int_entry = qmc_read16(qmc->int_curr);
1243 	}
1244 }
1245 
1246 static irqreturn_t qmc_irq_handler(int irq, void *priv)
1247 {
1248 	struct qmc *qmc = (struct qmc *)priv;
1249 	u16 scce;
1250 
1251 	scce = qmc_read16(qmc->scc_regs + SCC_SCCE);
1252 	qmc_write16(qmc->scc_regs + SCC_SCCE, scce);
1253 
1254 	if (unlikely(scce & SCC_SCCE_IQOV))
1255 		dev_info(qmc->dev, "IRQ queue overflow\n");
1256 
1257 	if (unlikely(scce & SCC_SCCE_GUN))
1258 		dev_err(qmc->dev, "Global transmitter underrun\n");
1259 
1260 	if (unlikely(scce & SCC_SCCE_GOV))
1261 		dev_err(qmc->dev, "Global receiver overrun\n");
1262 
1263 	/* normal interrupt */
1264 	if (likely(scce & SCC_SCCE_GINT))
1265 		qmc_irq_gint(qmc);
1266 
1267 	return IRQ_HANDLED;
1268 }
1269 
1270 static int qmc_probe(struct platform_device *pdev)
1271 {
1272 	struct device_node *np = pdev->dev.of_node;
1273 	unsigned int nb_chans;
1274 	struct resource *res;
1275 	struct qmc *qmc;
1276 	int irq;
1277 	int ret;
1278 
1279 	qmc = devm_kzalloc(&pdev->dev, sizeof(*qmc), GFP_KERNEL);
1280 	if (!qmc)
1281 		return -ENOMEM;
1282 
1283 	qmc->dev = &pdev->dev;
1284 	INIT_LIST_HEAD(&qmc->chan_head);
1285 
1286 	qmc->scc_regs = devm_platform_ioremap_resource_byname(pdev, "scc_regs");
1287 	if (IS_ERR(qmc->scc_regs))
1288 		return PTR_ERR(qmc->scc_regs);
1289 
1290 
1291 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "scc_pram");
1292 	if (!res)
1293 		return -EINVAL;
1294 	qmc->scc_pram_offset = res->start - get_immrbase();
1295 	qmc->scc_pram = devm_ioremap_resource(qmc->dev, res);
1296 	if (IS_ERR(qmc->scc_pram))
1297 		return PTR_ERR(qmc->scc_pram);
1298 
1299 	qmc->dpram  = devm_platform_ioremap_resource_byname(pdev, "dpram");
1300 	if (IS_ERR(qmc->dpram))
1301 		return PTR_ERR(qmc->dpram);
1302 
1303 	qmc->tsa_serial = devm_tsa_serial_get_byphandle(qmc->dev, np, "fsl,tsa-serial");
1304 	if (IS_ERR(qmc->tsa_serial)) {
1305 		return dev_err_probe(qmc->dev, PTR_ERR(qmc->tsa_serial),
1306 				     "Failed to get TSA serial\n");
1307 	}
1308 
1309 	/* Connect the serial (SCC) to TSA */
1310 	ret = tsa_serial_connect(qmc->tsa_serial);
1311 	if (ret) {
1312 		dev_err(qmc->dev, "Failed to connect TSA serial\n");
1313 		return ret;
1314 	}
1315 
1316 	/* Parse channels informationss */
1317 	ret = qmc_of_parse_chans(qmc, np);
1318 	if (ret)
1319 		goto err_tsa_serial_disconnect;
1320 
1321 	nb_chans = qmc_nb_chans(qmc);
1322 
1323 	/* Init GMSR_H and GMSR_L registers */
1324 	qmc_write32(qmc->scc_regs + SCC_GSMRH,
1325 		    SCC_GSMRH_CDS | SCC_GSMRH_CTSS | SCC_GSMRH_CDP | SCC_GSMRH_CTSP);
1326 
1327 	/* enable QMC mode */
1328 	qmc_write32(qmc->scc_regs + SCC_GSMRL, SCC_GSMRL_MODE_QMC);
1329 
1330 	/*
1331 	 * Allocate the buffer descriptor table
1332 	 * 8 rx and 8 tx descriptors per channel
1333 	 */
1334 	qmc->bd_size = (nb_chans * (QMC_NB_TXBDS + QMC_NB_RXBDS)) * sizeof(cbd_t);
1335 	qmc->bd_table = dmam_alloc_coherent(qmc->dev, qmc->bd_size,
1336 		&qmc->bd_dma_addr, GFP_KERNEL);
1337 	if (!qmc->bd_table) {
1338 		dev_err(qmc->dev, "Failed to allocate bd table\n");
1339 		ret = -ENOMEM;
1340 		goto err_tsa_serial_disconnect;
1341 	}
1342 	memset(qmc->bd_table, 0, qmc->bd_size);
1343 
1344 	qmc_write32(qmc->scc_pram + QMC_GBL_MCBASE, qmc->bd_dma_addr);
1345 
1346 	/* Allocate the interrupt table */
1347 	qmc->int_size = QMC_NB_INTS * sizeof(u16);
1348 	qmc->int_table = dmam_alloc_coherent(qmc->dev, qmc->int_size,
1349 		&qmc->int_dma_addr, GFP_KERNEL);
1350 	if (!qmc->int_table) {
1351 		dev_err(qmc->dev, "Failed to allocate interrupt table\n");
1352 		ret = -ENOMEM;
1353 		goto err_tsa_serial_disconnect;
1354 	}
1355 	memset(qmc->int_table, 0, qmc->int_size);
1356 
1357 	qmc->int_curr = qmc->int_table;
1358 	qmc_write32(qmc->scc_pram + QMC_GBL_INTBASE, qmc->int_dma_addr);
1359 	qmc_write32(qmc->scc_pram + QMC_GBL_INTPTR, qmc->int_dma_addr);
1360 
1361 	/* Set MRBLR (valid for HDLC only) max MRU + max CRC */
1362 	qmc_write16(qmc->scc_pram + QMC_GBL_MRBLR, HDLC_MAX_MRU + 4);
1363 
1364 	qmc_write16(qmc->scc_pram + QMC_GBL_GRFTHR, 1);
1365 	qmc_write16(qmc->scc_pram + QMC_GBL_GRFCNT, 1);
1366 
1367 	qmc_write32(qmc->scc_pram + QMC_GBL_C_MASK32, 0xDEBB20E3);
1368 	qmc_write16(qmc->scc_pram + QMC_GBL_C_MASK16, 0xF0B8);
1369 
1370 	ret = qmc_setup_tsa(qmc);
1371 	if (ret)
1372 		goto err_tsa_serial_disconnect;
1373 
1374 	qmc_write16(qmc->scc_pram + QMC_GBL_QMCSTATE, 0x8000);
1375 
1376 	ret = qmc_setup_chans(qmc);
1377 	if (ret)
1378 		goto err_tsa_serial_disconnect;
1379 
1380 	/* Init interrupts table */
1381 	ret = qmc_setup_ints(qmc);
1382 	if (ret)
1383 		goto err_tsa_serial_disconnect;
1384 
1385 	/* Disable and clear interrupts,  set the irq handler */
1386 	qmc_write16(qmc->scc_regs + SCC_SCCM, 0x0000);
1387 	qmc_write16(qmc->scc_regs + SCC_SCCE, 0x000F);
1388 	irq = platform_get_irq(pdev, 0);
1389 	if (irq < 0)
1390 		goto err_tsa_serial_disconnect;
1391 	ret = devm_request_irq(qmc->dev, irq, qmc_irq_handler, 0, "qmc", qmc);
1392 	if (ret < 0)
1393 		goto err_tsa_serial_disconnect;
1394 
1395 	/* Enable interrupts */
1396 	qmc_write16(qmc->scc_regs + SCC_SCCM,
1397 		SCC_SCCE_IQOV | SCC_SCCE_GINT | SCC_SCCE_GUN | SCC_SCCE_GOV);
1398 
1399 	ret = qmc_finalize_chans(qmc);
1400 	if (ret < 0)
1401 		goto err_disable_intr;
1402 
1403 	/* Enable transmiter and receiver */
1404 	qmc_setbits32(qmc->scc_regs + SCC_GSMRL, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
1405 
1406 	platform_set_drvdata(pdev, qmc);
1407 
1408 	return 0;
1409 
1410 err_disable_intr:
1411 	qmc_write16(qmc->scc_regs + SCC_SCCM, 0);
1412 
1413 err_tsa_serial_disconnect:
1414 	tsa_serial_disconnect(qmc->tsa_serial);
1415 	return ret;
1416 }
1417 
1418 static int qmc_remove(struct platform_device *pdev)
1419 {
1420 	struct qmc *qmc = platform_get_drvdata(pdev);
1421 
1422 	/* Disable transmiter and receiver */
1423 	qmc_setbits32(qmc->scc_regs + SCC_GSMRL, 0);
1424 
1425 	/* Disable interrupts */
1426 	qmc_write16(qmc->scc_regs + SCC_SCCM, 0);
1427 
1428 	/* Disconnect the serial from TSA */
1429 	tsa_serial_disconnect(qmc->tsa_serial);
1430 
1431 	return 0;
1432 }
1433 
1434 static const struct of_device_id qmc_id_table[] = {
1435 	{ .compatible = "fsl,cpm1-scc-qmc" },
1436 	{} /* sentinel */
1437 };
1438 MODULE_DEVICE_TABLE(of, qmc_id_table);
1439 
1440 static struct platform_driver qmc_driver = {
1441 	.driver = {
1442 		.name = "fsl-qmc",
1443 		.of_match_table = of_match_ptr(qmc_id_table),
1444 	},
1445 	.probe = qmc_probe,
1446 	.remove = qmc_remove,
1447 };
1448 module_platform_driver(qmc_driver);
1449 
1450 struct qmc_chan *qmc_chan_get_byphandle(struct device_node *np, const char *phandle_name)
1451 {
1452 	struct of_phandle_args out_args;
1453 	struct platform_device *pdev;
1454 	struct qmc_chan *qmc_chan;
1455 	struct qmc *qmc;
1456 	int ret;
1457 
1458 	ret = of_parse_phandle_with_fixed_args(np, phandle_name, 1, 0,
1459 					       &out_args);
1460 	if (ret < 0)
1461 		return ERR_PTR(ret);
1462 
1463 	if (!of_match_node(qmc_driver.driver.of_match_table, out_args.np)) {
1464 		of_node_put(out_args.np);
1465 		return ERR_PTR(-EINVAL);
1466 	}
1467 
1468 	pdev = of_find_device_by_node(out_args.np);
1469 	of_node_put(out_args.np);
1470 	if (!pdev)
1471 		return ERR_PTR(-ENODEV);
1472 
1473 	qmc = platform_get_drvdata(pdev);
1474 	if (!qmc) {
1475 		platform_device_put(pdev);
1476 		return ERR_PTR(-EPROBE_DEFER);
1477 	}
1478 
1479 	if (out_args.args_count != 1) {
1480 		platform_device_put(pdev);
1481 		return ERR_PTR(-EINVAL);
1482 	}
1483 
1484 	if (out_args.args[0] >= ARRAY_SIZE(qmc->chans)) {
1485 		platform_device_put(pdev);
1486 		return ERR_PTR(-EINVAL);
1487 	}
1488 
1489 	qmc_chan = qmc->chans[out_args.args[0]];
1490 	if (!qmc_chan) {
1491 		platform_device_put(pdev);
1492 		return ERR_PTR(-ENOENT);
1493 	}
1494 
1495 	return qmc_chan;
1496 }
1497 EXPORT_SYMBOL(qmc_chan_get_byphandle);
1498 
1499 void qmc_chan_put(struct qmc_chan *chan)
1500 {
1501 	put_device(chan->qmc->dev);
1502 }
1503 EXPORT_SYMBOL(qmc_chan_put);
1504 
1505 static void devm_qmc_chan_release(struct device *dev, void *res)
1506 {
1507 	struct qmc_chan **qmc_chan = res;
1508 
1509 	qmc_chan_put(*qmc_chan);
1510 }
1511 
1512 struct qmc_chan *devm_qmc_chan_get_byphandle(struct device *dev,
1513 					     struct device_node *np,
1514 					     const char *phandle_name)
1515 {
1516 	struct qmc_chan *qmc_chan;
1517 	struct qmc_chan **dr;
1518 
1519 	dr = devres_alloc(devm_qmc_chan_release, sizeof(*dr), GFP_KERNEL);
1520 	if (!dr)
1521 		return ERR_PTR(-ENOMEM);
1522 
1523 	qmc_chan = qmc_chan_get_byphandle(np, phandle_name);
1524 	if (!IS_ERR(qmc_chan)) {
1525 		*dr = qmc_chan;
1526 		devres_add(dev, dr);
1527 	} else {
1528 		devres_free(dr);
1529 	}
1530 
1531 	return qmc_chan;
1532 }
1533 EXPORT_SYMBOL(devm_qmc_chan_get_byphandle);
1534 
1535 MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
1536 MODULE_DESCRIPTION("CPM QMC driver");
1537 MODULE_LICENSE("GPL");
1538