xref: /linux/drivers/soc/fsl/qe/qmc.c (revision 55d0969c451159cff86949b38c39171cab962069)
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/bitfield.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/firmware.h>
14 #include <linux/hdlc.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_platform.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <soc/fsl/cpm.h>
23 #include <soc/fsl/qe/ucc_slow.h>
24 #include <soc/fsl/qe/qe.h>
25 #include <sysdev/fsl_soc.h>
26 #include "tsa.h"
27 
28 /* SCC general mode register low (32 bits) (GUMR_L in QE) */
29 #define SCC_GSMRL	0x00
30 #define SCC_GSMRL_ENR		BIT(5)
31 #define SCC_GSMRL_ENT		BIT(4)
32 #define SCC_GSMRL_MODE_MASK	GENMASK(3, 0)
33 #define SCC_CPM1_GSMRL_MODE_QMC	FIELD_PREP_CONST(SCC_GSMRL_MODE_MASK, 0x0A)
34 #define SCC_QE_GSMRL_MODE_QMC	FIELD_PREP_CONST(SCC_GSMRL_MODE_MASK, 0x02)
35 
36 /* SCC general mode register high (32 bits) (identical to GUMR_H in QE) */
37 #define SCC_GSMRH	0x04
38 #define   SCC_GSMRH_CTSS	BIT(7)
39 #define   SCC_GSMRH_CDS		BIT(8)
40 #define   SCC_GSMRH_CTSP	BIT(9)
41 #define   SCC_GSMRH_CDP		BIT(10)
42 #define   SCC_GSMRH_TTX		BIT(11)
43 #define   SCC_GSMRH_TRX		BIT(12)
44 
45 /* SCC event register (16 bits) (identical to UCCE in QE) */
46 #define SCC_SCCE	0x10
47 #define   SCC_SCCE_IQOV		BIT(3)
48 #define   SCC_SCCE_GINT		BIT(2)
49 #define   SCC_SCCE_GUN		BIT(1)
50 #define   SCC_SCCE_GOV		BIT(0)
51 
52 /* SCC mask register (16 bits) */
53 #define SCC_SCCM	0x14
54 
55 /* UCC Extended Mode Register (8 bits, QE only) */
56 #define SCC_QE_UCC_GUEMR	0x90
57 
58 /* Multichannel base pointer (32 bits) */
59 #define QMC_GBL_MCBASE		0x00
60 /* Multichannel controller state (16 bits) */
61 #define QMC_GBL_QMCSTATE	0x04
62 /* Maximum receive buffer length (16 bits) */
63 #define QMC_GBL_MRBLR		0x06
64 /* Tx time-slot assignment table pointer (16 bits) */
65 #define QMC_GBL_TX_S_PTR	0x08
66 /* Rx pointer (16 bits) */
67 #define QMC_GBL_RXPTR		0x0A
68 /* Global receive frame threshold (16 bits) */
69 #define QMC_GBL_GRFTHR		0x0C
70 /* Global receive frame count (16 bits) */
71 #define QMC_GBL_GRFCNT		0x0E
72 /* Multichannel interrupt base address (32 bits) */
73 #define QMC_GBL_INTBASE		0x10
74 /* Multichannel interrupt pointer (32 bits) */
75 #define QMC_GBL_INTPTR		0x14
76 /* Rx time-slot assignment table pointer (16 bits) */
77 #define QMC_GBL_RX_S_PTR	0x18
78 /* Tx pointer (16 bits) */
79 #define QMC_GBL_TXPTR		0x1A
80 /* CRC constant (32 bits) */
81 #define QMC_GBL_C_MASK32	0x1C
82 /* Time slot assignment table Rx (32 x 16 bits) */
83 #define QMC_GBL_TSATRX		0x20
84 /* Time slot assignment table Tx (32 x 16 bits) */
85 #define QMC_GBL_TSATTX		0x60
86 /* CRC constant (16 bits) */
87 #define QMC_GBL_C_MASK16	0xA0
88 /* Rx framer base pointer (16 bits, QE only) */
89 #define QMC_QE_GBL_RX_FRM_BASE	0xAC
90 /* Tx framer base pointer (16 bits, QE only) */
91 #define QMC_QE_GBL_TX_FRM_BASE	0xAE
92 /* A reserved area (0xB0 -> 0xC3) that must be initialized to 0 (QE only) */
93 #define QMC_QE_GBL_RSV_B0_START	0xB0
94 #define QMC_QE_GBL_RSV_B0_SIZE	0x14
95 /* QMC Global Channel specific base (32 bits, QE only) */
96 #define QMC_QE_GBL_GCSBASE	0xC4
97 
98 /* TSA entry (16bit entry in TSATRX and TSATTX) */
99 #define QMC_TSA_VALID		BIT(15)
100 #define QMC_TSA_WRAP		BIT(14)
101 #define QMC_TSA_MASK_MASKH	GENMASK(13, 12)
102 #define QMC_TSA_MASK_MASKL	GENMASK(5, 0)
103 #define QMC_TSA_MASK_8BIT	(FIELD_PREP_CONST(QMC_TSA_MASK_MASKH, 0x3) | \
104 				 FIELD_PREP_CONST(QMC_TSA_MASK_MASKL, 0x3F))
105 #define QMC_TSA_CHANNEL_MASK	GENMASK(11, 6)
106 #define QMC_TSA_CHANNEL(x)	FIELD_PREP(QMC_TSA_CHANNEL_MASK, x)
107 
108 /* Tx buffer descriptor base address (16 bits, offset from MCBASE) */
109 #define QMC_SPE_TBASE	0x00
110 
111 /* Channel mode register (16 bits) */
112 #define QMC_SPE_CHAMR	0x02
113 #define   QMC_SPE_CHAMR_MODE_MASK	GENMASK(15, 15)
114 #define   QMC_SPE_CHAMR_MODE_HDLC	FIELD_PREP_CONST(QMC_SPE_CHAMR_MODE_MASK, 1)
115 #define   QMC_SPE_CHAMR_MODE_TRANSP	(FIELD_PREP_CONST(QMC_SPE_CHAMR_MODE_MASK, 0) | BIT(13))
116 #define   QMC_SPE_CHAMR_ENT		BIT(12)
117 #define   QMC_SPE_CHAMR_POL		BIT(8)
118 #define   QMC_SPE_CHAMR_HDLC_IDLM	BIT(13)
119 #define   QMC_SPE_CHAMR_HDLC_CRC	BIT(7)
120 #define   QMC_SPE_CHAMR_HDLC_NOF_MASK	GENMASK(3, 0)
121 #define   QMC_SPE_CHAMR_HDLC_NOF(x)	FIELD_PREP(QMC_SPE_CHAMR_HDLC_NOF_MASK, x)
122 #define   QMC_SPE_CHAMR_TRANSP_RD	BIT(14)
123 #define   QMC_SPE_CHAMR_TRANSP_SYNC	BIT(10)
124 
125 /* Tx internal state (32 bits) */
126 #define QMC_SPE_TSTATE	0x04
127 /* Tx buffer descriptor pointer (16 bits) */
128 #define QMC_SPE_TBPTR	0x0C
129 /* Zero-insertion state (32 bits) */
130 #define QMC_SPE_ZISTATE	0x14
131 /* Channel’s interrupt mask flags (16 bits) */
132 #define QMC_SPE_INTMSK	0x1C
133 /* Rx buffer descriptor base address (16 bits, offset from MCBASE) */
134 #define QMC_SPE_RBASE	0x20
135 /* HDLC: Maximum frame length register (16 bits) */
136 #define QMC_SPE_MFLR	0x22
137 /* TRANSPARENT: Transparent maximum receive length (16 bits) */
138 #define QMC_SPE_TMRBLR	0x22
139 /* Rx internal state (32 bits) */
140 #define QMC_SPE_RSTATE	0x24
141 /* Rx buffer descriptor pointer (16 bits) */
142 #define QMC_SPE_RBPTR	0x2C
143 /* Packs 4 bytes to 1 long word before writing to buffer (32 bits) */
144 #define QMC_SPE_RPACK	0x30
145 /* Zero deletion state (32 bits) */
146 #define QMC_SPE_ZDSTATE	0x34
147 
148 /* Transparent synchronization (16 bits) */
149 #define QMC_SPE_TRNSYNC 0x3C
150 #define   QMC_SPE_TRNSYNC_RX_MASK	GENMASK(15, 8)
151 #define   QMC_SPE_TRNSYNC_RX(x)		FIELD_PREP(QMC_SPE_TRNSYNC_RX_MASK, x)
152 #define   QMC_SPE_TRNSYNC_TX_MASK	GENMASK(7, 0)
153 #define   QMC_SPE_TRNSYNC_TX(x)		FIELD_PREP(QMC_SPE_TRNSYNC_TX_MASK, x)
154 
155 /* Interrupt related registers bits */
156 #define QMC_INT_V		BIT(15)
157 #define QMC_INT_W		BIT(14)
158 #define QMC_INT_NID		BIT(13)
159 #define QMC_INT_IDL		BIT(12)
160 #define QMC_INT_CHANNEL_MASK	GENMASK(11, 6)
161 #define QMC_INT_GET_CHANNEL(x)	FIELD_GET(QMC_INT_CHANNEL_MASK, x)
162 #define QMC_INT_MRF		BIT(5)
163 #define QMC_INT_UN		BIT(4)
164 #define QMC_INT_RXF		BIT(3)
165 #define QMC_INT_BSY		BIT(2)
166 #define QMC_INT_TXB		BIT(1)
167 #define QMC_INT_RXB		BIT(0)
168 
169 /* BD related registers bits */
170 #define QMC_BD_RX_E	BIT(15)
171 #define QMC_BD_RX_W	BIT(13)
172 #define QMC_BD_RX_I	BIT(12)
173 #define QMC_BD_RX_L	BIT(11)
174 #define QMC_BD_RX_F	BIT(10)
175 #define QMC_BD_RX_CM	BIT(9)
176 #define QMC_BD_RX_UB	BIT(7)
177 #define QMC_BD_RX_LG	BIT(5)
178 #define QMC_BD_RX_NO	BIT(4)
179 #define QMC_BD_RX_AB	BIT(3)
180 #define QMC_BD_RX_CR	BIT(2)
181 
182 #define QMC_BD_TX_R		BIT(15)
183 #define QMC_BD_TX_W		BIT(13)
184 #define QMC_BD_TX_I		BIT(12)
185 #define QMC_BD_TX_L		BIT(11)
186 #define QMC_BD_TX_TC		BIT(10)
187 #define QMC_BD_TX_CM		BIT(9)
188 #define QMC_BD_TX_UB		BIT(7)
189 #define QMC_BD_TX_PAD_MASK	GENMASK(3, 0)
190 #define QMC_BD_TX_PAD(x)	FIELD_PREP(QMC_BD_TX_PAD_MASK, x)
191 
192 /* Numbers of BDs and interrupt items */
193 #define QMC_NB_TXBDS	8
194 #define QMC_NB_RXBDS	8
195 #define QMC_NB_INTS	128
196 
197 struct qmc_xfer_desc {
198 	union {
199 		void (*tx_complete)(void *context);
200 		void (*rx_complete)(void *context, size_t length, unsigned int flags);
201 	};
202 	void *context;
203 };
204 
205 struct qmc_chan {
206 	struct list_head list;
207 	unsigned int id;
208 	struct qmc *qmc;
209 	void __iomem *s_param;
210 	enum qmc_mode mode;
211 	spinlock_t	ts_lock; /* Protect timeslots */
212 	u64	tx_ts_mask_avail;
213 	u64	tx_ts_mask;
214 	u64	rx_ts_mask_avail;
215 	u64	rx_ts_mask;
216 	bool is_reverse_data;
217 
218 	spinlock_t	tx_lock; /* Protect Tx related data */
219 	cbd_t __iomem *txbds;
220 	cbd_t __iomem *txbd_free;
221 	cbd_t __iomem *txbd_done;
222 	struct qmc_xfer_desc tx_desc[QMC_NB_TXBDS];
223 	u64	nb_tx_underrun;
224 	bool	is_tx_stopped;
225 
226 	spinlock_t	rx_lock; /* Protect Rx related data */
227 	cbd_t __iomem *rxbds;
228 	cbd_t __iomem *rxbd_free;
229 	cbd_t __iomem *rxbd_done;
230 	struct qmc_xfer_desc rx_desc[QMC_NB_RXBDS];
231 	u64	nb_rx_busy;
232 	int	rx_pending;
233 	bool	is_rx_halted;
234 	bool	is_rx_stopped;
235 };
236 
237 enum qmc_version {
238 	QMC_CPM1,
239 	QMC_QE,
240 };
241 
242 struct qmc_data {
243 	enum qmc_version version;
244 	u32 tstate; /* Initial TSTATE value */
245 	u32 rstate; /* Initial RSTATE value */
246 	u32 zistate; /* Initial ZISTATE value */
247 	u32 zdstate_hdlc; /* Initial ZDSTATE value (HDLC mode) */
248 	u32 zdstate_transp; /* Initial ZDSTATE value (Transparent mode) */
249 	u32 rpack; /* Initial RPACK value */
250 };
251 
252 struct qmc {
253 	struct device *dev;
254 	const struct qmc_data *data;
255 	struct tsa_serial *tsa_serial;
256 	void __iomem *scc_regs;
257 	void __iomem *scc_pram;
258 	void __iomem *dpram;
259 	u16 scc_pram_offset;
260 	u32 dpram_offset;
261 	u32 qe_subblock;
262 	cbd_t __iomem *bd_table;
263 	dma_addr_t bd_dma_addr;
264 	size_t bd_size;
265 	u16 __iomem *int_table;
266 	u16 __iomem *int_curr;
267 	dma_addr_t int_dma_addr;
268 	size_t int_size;
269 	bool is_tsa_64rxtx;
270 	struct list_head chan_head;
271 	struct qmc_chan *chans[64];
272 };
273 
274 static void qmc_write8(void __iomem *addr, u8 val)
275 {
276 	iowrite8(val, addr);
277 }
278 
279 static void qmc_write16(void __iomem *addr, u16 val)
280 {
281 	iowrite16be(val, addr);
282 }
283 
284 static u16 qmc_read16(void __iomem *addr)
285 {
286 	return ioread16be(addr);
287 }
288 
289 static void qmc_setbits16(void __iomem *addr, u16 set)
290 {
291 	qmc_write16(addr, qmc_read16(addr) | set);
292 }
293 
294 static void qmc_clrbits16(void __iomem *addr, u16 clr)
295 {
296 	qmc_write16(addr, qmc_read16(addr) & ~clr);
297 }
298 
299 static void qmc_clrsetbits16(void __iomem *addr, u16 clr, u16 set)
300 {
301 	qmc_write16(addr, (qmc_read16(addr) & ~clr) | set);
302 }
303 
304 static void qmc_write32(void __iomem *addr, u32 val)
305 {
306 	iowrite32be(val, addr);
307 }
308 
309 static u32 qmc_read32(void __iomem *addr)
310 {
311 	return ioread32be(addr);
312 }
313 
314 static void qmc_setbits32(void __iomem *addr, u32 set)
315 {
316 	qmc_write32(addr, qmc_read32(addr) | set);
317 }
318 
319 static bool qmc_is_qe(const struct qmc *qmc)
320 {
321 	if (IS_ENABLED(CONFIG_QUICC_ENGINE) && IS_ENABLED(CONFIG_CPM))
322 		return qmc->data->version == QMC_QE;
323 
324 	return IS_ENABLED(CONFIG_QUICC_ENGINE);
325 }
326 
327 int qmc_chan_get_info(struct qmc_chan *chan, struct qmc_chan_info *info)
328 {
329 	struct tsa_serial_info tsa_info;
330 	unsigned long flags;
331 	int ret;
332 
333 	/* Retrieve info from the TSA related serial */
334 	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &tsa_info);
335 	if (ret)
336 		return ret;
337 
338 	spin_lock_irqsave(&chan->ts_lock, flags);
339 
340 	info->mode = chan->mode;
341 	info->rx_fs_rate = tsa_info.rx_fs_rate;
342 	info->rx_bit_rate = tsa_info.rx_bit_rate;
343 	info->nb_tx_ts = hweight64(chan->tx_ts_mask);
344 	info->tx_fs_rate = tsa_info.tx_fs_rate;
345 	info->tx_bit_rate = tsa_info.tx_bit_rate;
346 	info->nb_rx_ts = hweight64(chan->rx_ts_mask);
347 
348 	spin_unlock_irqrestore(&chan->ts_lock, flags);
349 
350 	return 0;
351 }
352 EXPORT_SYMBOL(qmc_chan_get_info);
353 
354 int qmc_chan_get_ts_info(struct qmc_chan *chan, struct qmc_chan_ts_info *ts_info)
355 {
356 	unsigned long flags;
357 
358 	spin_lock_irqsave(&chan->ts_lock, flags);
359 
360 	ts_info->rx_ts_mask_avail = chan->rx_ts_mask_avail;
361 	ts_info->tx_ts_mask_avail = chan->tx_ts_mask_avail;
362 	ts_info->rx_ts_mask = chan->rx_ts_mask;
363 	ts_info->tx_ts_mask = chan->tx_ts_mask;
364 
365 	spin_unlock_irqrestore(&chan->ts_lock, flags);
366 
367 	return 0;
368 }
369 EXPORT_SYMBOL(qmc_chan_get_ts_info);
370 
371 int qmc_chan_set_ts_info(struct qmc_chan *chan, const struct qmc_chan_ts_info *ts_info)
372 {
373 	unsigned long flags;
374 	int ret;
375 
376 	/* Only a subset of available timeslots is allowed */
377 	if ((ts_info->rx_ts_mask & chan->rx_ts_mask_avail) != ts_info->rx_ts_mask)
378 		return -EINVAL;
379 	if ((ts_info->tx_ts_mask & chan->tx_ts_mask_avail) != ts_info->tx_ts_mask)
380 		return -EINVAL;
381 
382 	/* In case of common rx/tx table, rx/tx masks must be identical */
383 	if (chan->qmc->is_tsa_64rxtx) {
384 		if (ts_info->rx_ts_mask != ts_info->tx_ts_mask)
385 			return -EINVAL;
386 	}
387 
388 	spin_lock_irqsave(&chan->ts_lock, flags);
389 
390 	if ((chan->tx_ts_mask != ts_info->tx_ts_mask && !chan->is_tx_stopped) ||
391 	    (chan->rx_ts_mask != ts_info->rx_ts_mask && !chan->is_rx_stopped)) {
392 		dev_err(chan->qmc->dev, "Channel rx and/or tx not stopped\n");
393 		ret = -EBUSY;
394 	} else {
395 		chan->tx_ts_mask = ts_info->tx_ts_mask;
396 		chan->rx_ts_mask = ts_info->rx_ts_mask;
397 		ret = 0;
398 	}
399 	spin_unlock_irqrestore(&chan->ts_lock, flags);
400 
401 	return ret;
402 }
403 EXPORT_SYMBOL(qmc_chan_set_ts_info);
404 
405 int qmc_chan_set_param(struct qmc_chan *chan, const struct qmc_chan_param *param)
406 {
407 	if (param->mode != chan->mode)
408 		return -EINVAL;
409 
410 	switch (param->mode) {
411 	case QMC_HDLC:
412 		if (param->hdlc.max_rx_buf_size % 4 ||
413 		    param->hdlc.max_rx_buf_size < 8)
414 			return -EINVAL;
415 
416 		qmc_write16(chan->qmc->scc_pram + QMC_GBL_MRBLR,
417 			    param->hdlc.max_rx_buf_size - 8);
418 		qmc_write16(chan->s_param + QMC_SPE_MFLR,
419 			    param->hdlc.max_rx_frame_size);
420 		if (param->hdlc.is_crc32) {
421 			qmc_setbits16(chan->s_param + QMC_SPE_CHAMR,
422 				      QMC_SPE_CHAMR_HDLC_CRC);
423 		} else {
424 			qmc_clrbits16(chan->s_param + QMC_SPE_CHAMR,
425 				      QMC_SPE_CHAMR_HDLC_CRC);
426 		}
427 		break;
428 
429 	case QMC_TRANSPARENT:
430 		qmc_write16(chan->s_param + QMC_SPE_TMRBLR,
431 			    param->transp.max_rx_buf_size);
432 		break;
433 
434 	default:
435 		return -EINVAL;
436 	}
437 
438 	return 0;
439 }
440 EXPORT_SYMBOL(qmc_chan_set_param);
441 
442 int qmc_chan_write_submit(struct qmc_chan *chan, dma_addr_t addr, size_t length,
443 			  void (*complete)(void *context), void *context)
444 {
445 	struct qmc_xfer_desc *xfer_desc;
446 	unsigned long flags;
447 	cbd_t __iomem *bd;
448 	u16 ctrl;
449 	int ret;
450 
451 	/*
452 	 * R bit  UB bit
453 	 *   0       0  : The BD is free
454 	 *   1       1  : The BD is in used, waiting for transfer
455 	 *   0       1  : The BD is in used, waiting for completion
456 	 *   1       0  : Should not append
457 	 */
458 
459 	spin_lock_irqsave(&chan->tx_lock, flags);
460 	bd = chan->txbd_free;
461 
462 	ctrl = qmc_read16(&bd->cbd_sc);
463 	if (ctrl & (QMC_BD_TX_R | QMC_BD_TX_UB)) {
464 		/* We are full ... */
465 		ret = -EBUSY;
466 		goto end;
467 	}
468 
469 	qmc_write16(&bd->cbd_datlen, length);
470 	qmc_write32(&bd->cbd_bufaddr, addr);
471 
472 	xfer_desc = &chan->tx_desc[bd - chan->txbds];
473 	xfer_desc->tx_complete = complete;
474 	xfer_desc->context = context;
475 
476 	/* Activate the descriptor */
477 	ctrl |= (QMC_BD_TX_R | QMC_BD_TX_UB);
478 	wmb(); /* Be sure to flush the descriptor before control update */
479 	qmc_write16(&bd->cbd_sc, ctrl);
480 
481 	if (!chan->is_tx_stopped)
482 		qmc_setbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_POL);
483 
484 	if (ctrl & QMC_BD_TX_W)
485 		chan->txbd_free = chan->txbds;
486 	else
487 		chan->txbd_free++;
488 
489 	ret = 0;
490 
491 end:
492 	spin_unlock_irqrestore(&chan->tx_lock, flags);
493 	return ret;
494 }
495 EXPORT_SYMBOL(qmc_chan_write_submit);
496 
497 static void qmc_chan_write_done(struct qmc_chan *chan)
498 {
499 	struct qmc_xfer_desc *xfer_desc;
500 	void (*complete)(void *context);
501 	unsigned long flags;
502 	void *context;
503 	cbd_t __iomem *bd;
504 	u16 ctrl;
505 
506 	/*
507 	 * R bit  UB bit
508 	 *   0       0  : The BD is free
509 	 *   1       1  : The BD is in used, waiting for transfer
510 	 *   0       1  : The BD is in used, waiting for completion
511 	 *   1       0  : Should not append
512 	 */
513 
514 	spin_lock_irqsave(&chan->tx_lock, flags);
515 	bd = chan->txbd_done;
516 
517 	ctrl = qmc_read16(&bd->cbd_sc);
518 	while (!(ctrl & QMC_BD_TX_R)) {
519 		if (!(ctrl & QMC_BD_TX_UB))
520 			goto end;
521 
522 		xfer_desc = &chan->tx_desc[bd - chan->txbds];
523 		complete = xfer_desc->tx_complete;
524 		context = xfer_desc->context;
525 		xfer_desc->tx_complete = NULL;
526 		xfer_desc->context = NULL;
527 
528 		qmc_write16(&bd->cbd_sc, ctrl & ~QMC_BD_TX_UB);
529 
530 		if (ctrl & QMC_BD_TX_W)
531 			chan->txbd_done = chan->txbds;
532 		else
533 			chan->txbd_done++;
534 
535 		if (complete) {
536 			spin_unlock_irqrestore(&chan->tx_lock, flags);
537 			complete(context);
538 			spin_lock_irqsave(&chan->tx_lock, flags);
539 		}
540 
541 		bd = chan->txbd_done;
542 		ctrl = qmc_read16(&bd->cbd_sc);
543 	}
544 
545 end:
546 	spin_unlock_irqrestore(&chan->tx_lock, flags);
547 }
548 
549 int qmc_chan_read_submit(struct qmc_chan *chan, dma_addr_t addr, size_t length,
550 			 void (*complete)(void *context, size_t length, unsigned int flags),
551 			 void *context)
552 {
553 	struct qmc_xfer_desc *xfer_desc;
554 	unsigned long flags;
555 	cbd_t __iomem *bd;
556 	u16 ctrl;
557 	int ret;
558 
559 	/*
560 	 * E bit  UB bit
561 	 *   0       0  : The BD is free
562 	 *   1       1  : The BD is in used, waiting for transfer
563 	 *   0       1  : The BD is in used, waiting for completion
564 	 *   1       0  : Should not append
565 	 */
566 
567 	spin_lock_irqsave(&chan->rx_lock, flags);
568 	bd = chan->rxbd_free;
569 
570 	ctrl = qmc_read16(&bd->cbd_sc);
571 	if (ctrl & (QMC_BD_RX_E | QMC_BD_RX_UB)) {
572 		/* We are full ... */
573 		ret = -EBUSY;
574 		goto end;
575 	}
576 
577 	qmc_write16(&bd->cbd_datlen, 0); /* data length is updated by the QMC */
578 	qmc_write32(&bd->cbd_bufaddr, addr);
579 
580 	xfer_desc = &chan->rx_desc[bd - chan->rxbds];
581 	xfer_desc->rx_complete = complete;
582 	xfer_desc->context = context;
583 
584 	/* Clear previous status flags */
585 	ctrl &= ~(QMC_BD_RX_L | QMC_BD_RX_F | QMC_BD_RX_LG | QMC_BD_RX_NO |
586 		  QMC_BD_RX_AB | QMC_BD_RX_CR);
587 
588 	/* Activate the descriptor */
589 	ctrl |= (QMC_BD_RX_E | QMC_BD_RX_UB);
590 	wmb(); /* Be sure to flush data before descriptor activation */
591 	qmc_write16(&bd->cbd_sc, ctrl);
592 
593 	/* Restart receiver if needed */
594 	if (chan->is_rx_halted && !chan->is_rx_stopped) {
595 		/* Restart receiver */
596 		qmc_write32(chan->s_param + QMC_SPE_RPACK, chan->qmc->data->rpack);
597 		qmc_write32(chan->s_param + QMC_SPE_ZDSTATE,
598 			    chan->mode == QMC_TRANSPARENT ?
599 				chan->qmc->data->zdstate_transp :
600 				chan->qmc->data->zdstate_hdlc);
601 		qmc_write32(chan->s_param + QMC_SPE_RSTATE, chan->qmc->data->rstate);
602 		chan->is_rx_halted = false;
603 	}
604 	chan->rx_pending++;
605 
606 	if (ctrl & QMC_BD_RX_W)
607 		chan->rxbd_free = chan->rxbds;
608 	else
609 		chan->rxbd_free++;
610 
611 	ret = 0;
612 end:
613 	spin_unlock_irqrestore(&chan->rx_lock, flags);
614 	return ret;
615 }
616 EXPORT_SYMBOL(qmc_chan_read_submit);
617 
618 static void qmc_chan_read_done(struct qmc_chan *chan)
619 {
620 	void (*complete)(void *context, size_t size, unsigned int flags);
621 	struct qmc_xfer_desc *xfer_desc;
622 	unsigned long flags;
623 	cbd_t __iomem *bd;
624 	void *context;
625 	u16 datalen;
626 	u16 ctrl;
627 
628 	/*
629 	 * E bit  UB bit
630 	 *   0       0  : The BD is free
631 	 *   1       1  : The BD is in used, waiting for transfer
632 	 *   0       1  : The BD is in used, waiting for completion
633 	 *   1       0  : Should not append
634 	 */
635 
636 	spin_lock_irqsave(&chan->rx_lock, flags);
637 	bd = chan->rxbd_done;
638 
639 	ctrl = qmc_read16(&bd->cbd_sc);
640 	while (!(ctrl & QMC_BD_RX_E)) {
641 		if (!(ctrl & QMC_BD_RX_UB))
642 			goto end;
643 
644 		xfer_desc = &chan->rx_desc[bd - chan->rxbds];
645 		complete = xfer_desc->rx_complete;
646 		context = xfer_desc->context;
647 		xfer_desc->rx_complete = NULL;
648 		xfer_desc->context = NULL;
649 
650 		datalen = qmc_read16(&bd->cbd_datlen);
651 		qmc_write16(&bd->cbd_sc, ctrl & ~QMC_BD_RX_UB);
652 
653 		if (ctrl & QMC_BD_RX_W)
654 			chan->rxbd_done = chan->rxbds;
655 		else
656 			chan->rxbd_done++;
657 
658 		chan->rx_pending--;
659 
660 		if (complete) {
661 			spin_unlock_irqrestore(&chan->rx_lock, flags);
662 
663 			/*
664 			 * Avoid conversion between internal hardware flags and
665 			 * the software API flags.
666 			 * -> Be sure that the software API flags are consistent
667 			 *    with the hardware flags
668 			 */
669 			BUILD_BUG_ON(QMC_RX_FLAG_HDLC_LAST  != QMC_BD_RX_L);
670 			BUILD_BUG_ON(QMC_RX_FLAG_HDLC_FIRST != QMC_BD_RX_F);
671 			BUILD_BUG_ON(QMC_RX_FLAG_HDLC_OVF   != QMC_BD_RX_LG);
672 			BUILD_BUG_ON(QMC_RX_FLAG_HDLC_UNA   != QMC_BD_RX_NO);
673 			BUILD_BUG_ON(QMC_RX_FLAG_HDLC_ABORT != QMC_BD_RX_AB);
674 			BUILD_BUG_ON(QMC_RX_FLAG_HDLC_CRC   != QMC_BD_RX_CR);
675 
676 			complete(context, datalen,
677 				 ctrl & (QMC_BD_RX_L | QMC_BD_RX_F | QMC_BD_RX_LG |
678 					 QMC_BD_RX_NO | QMC_BD_RX_AB | QMC_BD_RX_CR));
679 			spin_lock_irqsave(&chan->rx_lock, flags);
680 		}
681 
682 		bd = chan->rxbd_done;
683 		ctrl = qmc_read16(&bd->cbd_sc);
684 	}
685 
686 end:
687 	spin_unlock_irqrestore(&chan->rx_lock, flags);
688 }
689 
690 static int qmc_chan_setup_tsa_64rxtx(struct qmc_chan *chan, const struct tsa_serial_info *info,
691 				     bool enable)
692 {
693 	unsigned int i;
694 	u16 curr;
695 	u16 val;
696 
697 	/*
698 	 * Use a common Tx/Rx 64 entries table.
699 	 * Tx and Rx related stuffs must be identical
700 	 */
701 	if (chan->tx_ts_mask != chan->rx_ts_mask) {
702 		dev_err(chan->qmc->dev, "chan %u uses different Rx and Tx TS\n", chan->id);
703 		return -EINVAL;
704 	}
705 
706 	val = QMC_TSA_VALID | QMC_TSA_MASK_8BIT | QMC_TSA_CHANNEL(chan->id);
707 
708 	/* Check entries based on Rx stuff*/
709 	for (i = 0; i < info->nb_rx_ts; i++) {
710 		if (!(chan->rx_ts_mask & (((u64)1) << i)))
711 			continue;
712 
713 		curr = qmc_read16(chan->qmc->scc_pram + QMC_GBL_TSATRX + (i * 2));
714 		if (curr & QMC_TSA_VALID && (curr & ~QMC_TSA_WRAP) != val) {
715 			dev_err(chan->qmc->dev, "chan %u TxRx entry %d already used\n",
716 				chan->id, i);
717 			return -EBUSY;
718 		}
719 	}
720 
721 	/* Set entries based on Rx stuff*/
722 	for (i = 0; i < info->nb_rx_ts; i++) {
723 		if (!(chan->rx_ts_mask & (((u64)1) << i)))
724 			continue;
725 
726 		qmc_clrsetbits16(chan->qmc->scc_pram + QMC_GBL_TSATRX + (i * 2),
727 				 (u16)~QMC_TSA_WRAP, enable ? val : 0x0000);
728 	}
729 
730 	return 0;
731 }
732 
733 static int qmc_chan_setup_tsa_32rx(struct qmc_chan *chan, const struct tsa_serial_info *info,
734 				   bool enable)
735 {
736 	unsigned int i;
737 	u16 curr;
738 	u16 val;
739 
740 	/* Use a Rx 32 entries table */
741 
742 	val = QMC_TSA_VALID | QMC_TSA_MASK_8BIT | QMC_TSA_CHANNEL(chan->id);
743 
744 	/* Check entries based on Rx stuff */
745 	for (i = 0; i < info->nb_rx_ts; i++) {
746 		if (!(chan->rx_ts_mask & (((u64)1) << i)))
747 			continue;
748 
749 		curr = qmc_read16(chan->qmc->scc_pram + QMC_GBL_TSATRX + (i * 2));
750 		if (curr & QMC_TSA_VALID && (curr & ~QMC_TSA_WRAP) != val) {
751 			dev_err(chan->qmc->dev, "chan %u Rx entry %d already used\n",
752 				chan->id, i);
753 			return -EBUSY;
754 		}
755 	}
756 
757 	/* Set entries based on Rx stuff */
758 	for (i = 0; i < info->nb_rx_ts; i++) {
759 		if (!(chan->rx_ts_mask & (((u64)1) << i)))
760 			continue;
761 
762 		qmc_clrsetbits16(chan->qmc->scc_pram + QMC_GBL_TSATRX + (i * 2),
763 				 (u16)~QMC_TSA_WRAP, enable ? val : 0x0000);
764 	}
765 
766 	return 0;
767 }
768 
769 static int qmc_chan_setup_tsa_32tx(struct qmc_chan *chan, const struct tsa_serial_info *info,
770 				   bool enable)
771 {
772 	unsigned int i;
773 	u16 curr;
774 	u16 val;
775 
776 	/* Use a Tx 32 entries table */
777 
778 	val = QMC_TSA_VALID | QMC_TSA_MASK_8BIT | QMC_TSA_CHANNEL(chan->id);
779 
780 	/* Check entries based on Tx stuff */
781 	for (i = 0; i < info->nb_tx_ts; i++) {
782 		if (!(chan->tx_ts_mask & (((u64)1) << i)))
783 			continue;
784 
785 		curr = qmc_read16(chan->qmc->scc_pram + QMC_GBL_TSATTX + (i * 2));
786 		if (curr & QMC_TSA_VALID && (curr & ~QMC_TSA_WRAP) != val) {
787 			dev_err(chan->qmc->dev, "chan %u Tx entry %d already used\n",
788 				chan->id, i);
789 			return -EBUSY;
790 		}
791 	}
792 
793 	/* Set entries based on Tx stuff */
794 	for (i = 0; i < info->nb_tx_ts; i++) {
795 		if (!(chan->tx_ts_mask & (((u64)1) << i)))
796 			continue;
797 
798 		qmc_clrsetbits16(chan->qmc->scc_pram + QMC_GBL_TSATTX + (i * 2),
799 				 (u16)~QMC_TSA_WRAP, enable ? val : 0x0000);
800 	}
801 
802 	return 0;
803 }
804 
805 static int qmc_chan_setup_tsa_tx(struct qmc_chan *chan, bool enable)
806 {
807 	struct tsa_serial_info info;
808 	int ret;
809 
810 	/* Retrieve info from the TSA related serial */
811 	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &info);
812 	if (ret)
813 		return ret;
814 
815 	/* Setup entries */
816 	if (chan->qmc->is_tsa_64rxtx)
817 		return qmc_chan_setup_tsa_64rxtx(chan, &info, enable);
818 
819 	return qmc_chan_setup_tsa_32tx(chan, &info, enable);
820 }
821 
822 static int qmc_chan_setup_tsa_rx(struct qmc_chan *chan, bool enable)
823 {
824 	struct tsa_serial_info info;
825 	int ret;
826 
827 	/* Retrieve info from the TSA related serial */
828 	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &info);
829 	if (ret)
830 		return ret;
831 
832 	/* Setup entries */
833 	if (chan->qmc->is_tsa_64rxtx)
834 		return qmc_chan_setup_tsa_64rxtx(chan, &info, enable);
835 
836 	return qmc_chan_setup_tsa_32rx(chan, &info, enable);
837 }
838 
839 static int qmc_chan_cpm1_command(struct qmc_chan *chan, u8 qmc_opcode)
840 {
841 	return cpm_command(chan->id << 2, (qmc_opcode << 4) | 0x0E);
842 }
843 
844 static int qmc_chan_qe_command(struct qmc_chan *chan, u32 cmd)
845 {
846 	if (!qe_issue_cmd(cmd, chan->qmc->qe_subblock, chan->id, 0))
847 		return -EIO;
848 	return 0;
849 }
850 
851 static int qmc_chan_stop_rx(struct qmc_chan *chan)
852 {
853 	unsigned long flags;
854 	int ret;
855 
856 	spin_lock_irqsave(&chan->rx_lock, flags);
857 
858 	if (chan->is_rx_stopped) {
859 		/* The channel is already stopped -> simply return ok */
860 		ret = 0;
861 		goto end;
862 	}
863 
864 	/* Send STOP RECEIVE command */
865 	ret = qmc_is_qe(chan->qmc) ?
866 		qmc_chan_qe_command(chan, QE_QMC_STOP_RX) :
867 		qmc_chan_cpm1_command(chan, 0x0);
868 	if (ret) {
869 		dev_err(chan->qmc->dev, "chan %u: Send STOP RECEIVE failed (%d)\n",
870 			chan->id, ret);
871 		goto end;
872 	}
873 
874 	chan->is_rx_stopped = true;
875 
876 	if (!chan->qmc->is_tsa_64rxtx || chan->is_tx_stopped) {
877 		ret = qmc_chan_setup_tsa_rx(chan, false);
878 		if (ret) {
879 			dev_err(chan->qmc->dev, "chan %u: Disable tsa entries failed (%d)\n",
880 				chan->id, ret);
881 			goto end;
882 		}
883 	}
884 
885 end:
886 	spin_unlock_irqrestore(&chan->rx_lock, flags);
887 	return ret;
888 }
889 
890 static int qmc_chan_stop_tx(struct qmc_chan *chan)
891 {
892 	unsigned long flags;
893 	int ret;
894 
895 	spin_lock_irqsave(&chan->tx_lock, flags);
896 
897 	if (chan->is_tx_stopped) {
898 		/* The channel is already stopped -> simply return ok */
899 		ret = 0;
900 		goto end;
901 	}
902 
903 	/* Send STOP TRANSMIT command */
904 	ret = qmc_is_qe(chan->qmc) ?
905 		qmc_chan_qe_command(chan, QE_QMC_STOP_TX) :
906 		qmc_chan_cpm1_command(chan, 0x1);
907 	if (ret) {
908 		dev_err(chan->qmc->dev, "chan %u: Send STOP TRANSMIT failed (%d)\n",
909 			chan->id, ret);
910 		goto end;
911 	}
912 
913 	chan->is_tx_stopped = true;
914 
915 	if (!chan->qmc->is_tsa_64rxtx || chan->is_rx_stopped) {
916 		ret = qmc_chan_setup_tsa_tx(chan, false);
917 		if (ret) {
918 			dev_err(chan->qmc->dev, "chan %u: Disable tsa entries failed (%d)\n",
919 				chan->id, ret);
920 			goto end;
921 		}
922 	}
923 
924 end:
925 	spin_unlock_irqrestore(&chan->tx_lock, flags);
926 	return ret;
927 }
928 
929 static int qmc_chan_start_rx(struct qmc_chan *chan);
930 
931 int qmc_chan_stop(struct qmc_chan *chan, int direction)
932 {
933 	bool is_rx_rollback_needed = false;
934 	unsigned long flags;
935 	int ret = 0;
936 
937 	spin_lock_irqsave(&chan->ts_lock, flags);
938 
939 	if (direction & QMC_CHAN_READ) {
940 		is_rx_rollback_needed = !chan->is_rx_stopped;
941 		ret = qmc_chan_stop_rx(chan);
942 		if (ret)
943 			goto end;
944 	}
945 
946 	if (direction & QMC_CHAN_WRITE) {
947 		ret = qmc_chan_stop_tx(chan);
948 		if (ret) {
949 			/* Restart rx if needed */
950 			if (is_rx_rollback_needed)
951 				qmc_chan_start_rx(chan);
952 			goto end;
953 		}
954 	}
955 
956 end:
957 	spin_unlock_irqrestore(&chan->ts_lock, flags);
958 	return ret;
959 }
960 EXPORT_SYMBOL(qmc_chan_stop);
961 
962 static int qmc_setup_chan_trnsync(struct qmc *qmc, struct qmc_chan *chan)
963 {
964 	struct tsa_serial_info info;
965 	unsigned int w_rx, w_tx;
966 	u16 first_rx, last_tx;
967 	u16 trnsync;
968 	int ret;
969 
970 	/* Retrieve info from the TSA related serial */
971 	ret = tsa_serial_get_info(chan->qmc->tsa_serial, &info);
972 	if (ret)
973 		return ret;
974 
975 	w_rx = hweight64(chan->rx_ts_mask);
976 	w_tx = hweight64(chan->tx_ts_mask);
977 	if (w_rx <= 1 && w_tx <= 1) {
978 		dev_dbg(qmc->dev, "only one or zero ts -> disable trnsync\n");
979 		qmc_clrbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_TRANSP_SYNC);
980 		return 0;
981 	}
982 
983 	/* Find the first Rx TS allocated to the channel */
984 	first_rx = chan->rx_ts_mask ? __ffs64(chan->rx_ts_mask) + 1 : 0;
985 
986 	/* Find the last Tx TS allocated to the channel */
987 	last_tx = fls64(chan->tx_ts_mask);
988 
989 	trnsync = 0;
990 	if (info.nb_rx_ts)
991 		trnsync |= QMC_SPE_TRNSYNC_RX((first_rx % info.nb_rx_ts) * 2);
992 	if (info.nb_tx_ts)
993 		trnsync |= QMC_SPE_TRNSYNC_TX((last_tx % info.nb_tx_ts) * 2);
994 
995 	qmc_write16(chan->s_param + QMC_SPE_TRNSYNC, trnsync);
996 	qmc_setbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_TRANSP_SYNC);
997 
998 	dev_dbg(qmc->dev, "chan %u: trnsync=0x%04x, rx %u/%u 0x%llx, tx %u/%u 0x%llx\n",
999 		chan->id, trnsync,
1000 		first_rx, info.nb_rx_ts, chan->rx_ts_mask,
1001 		last_tx, info.nb_tx_ts, chan->tx_ts_mask);
1002 
1003 	return 0;
1004 }
1005 
1006 static int qmc_chan_start_rx(struct qmc_chan *chan)
1007 {
1008 	unsigned long flags;
1009 	int ret;
1010 
1011 	spin_lock_irqsave(&chan->rx_lock, flags);
1012 
1013 	if (!chan->is_rx_stopped) {
1014 		/* The channel is already started -> simply return ok */
1015 		ret = 0;
1016 		goto end;
1017 	}
1018 
1019 	ret = qmc_chan_setup_tsa_rx(chan, true);
1020 	if (ret) {
1021 		dev_err(chan->qmc->dev, "chan %u: Enable tsa entries failed (%d)\n",
1022 			chan->id, ret);
1023 		goto end;
1024 	}
1025 
1026 	if (chan->mode == QMC_TRANSPARENT) {
1027 		ret = qmc_setup_chan_trnsync(chan->qmc, chan);
1028 		if (ret) {
1029 			dev_err(chan->qmc->dev, "chan %u: setup TRNSYNC failed (%d)\n",
1030 				chan->id, ret);
1031 			goto end;
1032 		}
1033 	}
1034 
1035 	/* Restart the receiver */
1036 	qmc_write32(chan->s_param + QMC_SPE_RPACK, chan->qmc->data->rpack);
1037 	qmc_write32(chan->s_param + QMC_SPE_ZDSTATE,
1038 		    chan->mode == QMC_TRANSPARENT ?
1039 			chan->qmc->data->zdstate_transp :
1040 			chan->qmc->data->zdstate_hdlc);
1041 	qmc_write32(chan->s_param + QMC_SPE_RSTATE, chan->qmc->data->rstate);
1042 	chan->is_rx_halted = false;
1043 
1044 	chan->is_rx_stopped = false;
1045 
1046 end:
1047 	spin_unlock_irqrestore(&chan->rx_lock, flags);
1048 	return ret;
1049 }
1050 
1051 static int qmc_chan_start_tx(struct qmc_chan *chan)
1052 {
1053 	unsigned long flags;
1054 	int ret;
1055 
1056 	spin_lock_irqsave(&chan->tx_lock, flags);
1057 
1058 	if (!chan->is_tx_stopped) {
1059 		/* The channel is already started -> simply return ok */
1060 		ret = 0;
1061 		goto end;
1062 	}
1063 
1064 	ret = qmc_chan_setup_tsa_tx(chan, true);
1065 	if (ret) {
1066 		dev_err(chan->qmc->dev, "chan %u: Enable tsa entries failed (%d)\n",
1067 			chan->id, ret);
1068 		goto end;
1069 	}
1070 
1071 	if (chan->mode == QMC_TRANSPARENT) {
1072 		ret = qmc_setup_chan_trnsync(chan->qmc, chan);
1073 		if (ret) {
1074 			dev_err(chan->qmc->dev, "chan %u: setup TRNSYNC failed (%d)\n",
1075 				chan->id, ret);
1076 			goto end;
1077 		}
1078 	}
1079 
1080 	/*
1081 	 * Enable channel transmitter as it could be disabled if
1082 	 * qmc_chan_reset() was called.
1083 	 */
1084 	qmc_setbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_ENT);
1085 
1086 	/* Set the POL bit in the channel mode register */
1087 	qmc_setbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_POL);
1088 
1089 	chan->is_tx_stopped = false;
1090 
1091 end:
1092 	spin_unlock_irqrestore(&chan->tx_lock, flags);
1093 	return ret;
1094 }
1095 
1096 int qmc_chan_start(struct qmc_chan *chan, int direction)
1097 {
1098 	bool is_rx_rollback_needed = false;
1099 	unsigned long flags;
1100 	int ret = 0;
1101 
1102 	spin_lock_irqsave(&chan->ts_lock, flags);
1103 
1104 	if (direction & QMC_CHAN_READ) {
1105 		is_rx_rollback_needed = chan->is_rx_stopped;
1106 		ret = qmc_chan_start_rx(chan);
1107 		if (ret)
1108 			goto end;
1109 	}
1110 
1111 	if (direction & QMC_CHAN_WRITE) {
1112 		ret = qmc_chan_start_tx(chan);
1113 		if (ret) {
1114 			/* Restop rx if needed */
1115 			if (is_rx_rollback_needed)
1116 				qmc_chan_stop_rx(chan);
1117 			goto end;
1118 		}
1119 	}
1120 
1121 end:
1122 	spin_unlock_irqrestore(&chan->ts_lock, flags);
1123 	return ret;
1124 }
1125 EXPORT_SYMBOL(qmc_chan_start);
1126 
1127 static void qmc_chan_reset_rx(struct qmc_chan *chan)
1128 {
1129 	struct qmc_xfer_desc *xfer_desc;
1130 	unsigned long flags;
1131 	cbd_t __iomem *bd;
1132 	u16 ctrl;
1133 
1134 	spin_lock_irqsave(&chan->rx_lock, flags);
1135 	bd = chan->rxbds;
1136 	do {
1137 		ctrl = qmc_read16(&bd->cbd_sc);
1138 		qmc_write16(&bd->cbd_sc, ctrl & ~(QMC_BD_RX_UB | QMC_BD_RX_E));
1139 
1140 		xfer_desc = &chan->rx_desc[bd - chan->rxbds];
1141 		xfer_desc->rx_complete = NULL;
1142 		xfer_desc->context = NULL;
1143 
1144 		bd++;
1145 	} while (!(ctrl & QMC_BD_RX_W));
1146 
1147 	chan->rxbd_free = chan->rxbds;
1148 	chan->rxbd_done = chan->rxbds;
1149 	qmc_write16(chan->s_param + QMC_SPE_RBPTR,
1150 		    qmc_read16(chan->s_param + QMC_SPE_RBASE));
1151 
1152 	chan->rx_pending = 0;
1153 
1154 	spin_unlock_irqrestore(&chan->rx_lock, flags);
1155 }
1156 
1157 static void qmc_chan_reset_tx(struct qmc_chan *chan)
1158 {
1159 	struct qmc_xfer_desc *xfer_desc;
1160 	unsigned long flags;
1161 	cbd_t __iomem *bd;
1162 	u16 ctrl;
1163 
1164 	spin_lock_irqsave(&chan->tx_lock, flags);
1165 
1166 	/* Disable transmitter. It will be re-enable on qmc_chan_start() */
1167 	qmc_clrbits16(chan->s_param + QMC_SPE_CHAMR, QMC_SPE_CHAMR_ENT);
1168 
1169 	bd = chan->txbds;
1170 	do {
1171 		ctrl = qmc_read16(&bd->cbd_sc);
1172 		qmc_write16(&bd->cbd_sc, ctrl & ~(QMC_BD_TX_UB | QMC_BD_TX_R));
1173 
1174 		xfer_desc = &chan->tx_desc[bd - chan->txbds];
1175 		xfer_desc->tx_complete = NULL;
1176 		xfer_desc->context = NULL;
1177 
1178 		bd++;
1179 	} while (!(ctrl & QMC_BD_TX_W));
1180 
1181 	chan->txbd_free = chan->txbds;
1182 	chan->txbd_done = chan->txbds;
1183 	qmc_write16(chan->s_param + QMC_SPE_TBPTR,
1184 		    qmc_read16(chan->s_param + QMC_SPE_TBASE));
1185 
1186 	/* Reset TSTATE and ZISTATE to their initial value */
1187 	qmc_write32(chan->s_param + QMC_SPE_TSTATE, chan->qmc->data->tstate);
1188 	qmc_write32(chan->s_param + QMC_SPE_ZISTATE, chan->qmc->data->zistate);
1189 
1190 	spin_unlock_irqrestore(&chan->tx_lock, flags);
1191 }
1192 
1193 int qmc_chan_reset(struct qmc_chan *chan, int direction)
1194 {
1195 	if (direction & QMC_CHAN_READ)
1196 		qmc_chan_reset_rx(chan);
1197 
1198 	if (direction & QMC_CHAN_WRITE)
1199 		qmc_chan_reset_tx(chan);
1200 
1201 	return 0;
1202 }
1203 EXPORT_SYMBOL(qmc_chan_reset);
1204 
1205 static int qmc_check_chans(struct qmc *qmc)
1206 {
1207 	struct tsa_serial_info info;
1208 	struct qmc_chan *chan;
1209 	u64 tx_ts_assigned_mask;
1210 	u64 rx_ts_assigned_mask;
1211 	int ret;
1212 
1213 	/* Retrieve info from the TSA related serial */
1214 	ret = tsa_serial_get_info(qmc->tsa_serial, &info);
1215 	if (ret)
1216 		return ret;
1217 
1218 	if (info.nb_tx_ts > 64 || info.nb_rx_ts > 64) {
1219 		dev_err(qmc->dev, "Number of TSA Tx/Rx TS assigned not supported\n");
1220 		return -EINVAL;
1221 	}
1222 
1223 	/*
1224 	 * If more than 32 TS are assigned to this serial, one common table is
1225 	 * used for Tx and Rx and so masks must be equal for all channels.
1226 	 */
1227 	if (info.nb_tx_ts > 32 || info.nb_rx_ts > 32) {
1228 		if (info.nb_tx_ts != info.nb_rx_ts) {
1229 			dev_err(qmc->dev, "Number of TSA Tx/Rx TS assigned are not equal\n");
1230 			return -EINVAL;
1231 		}
1232 	}
1233 
1234 	tx_ts_assigned_mask = info.nb_tx_ts == 64 ? U64_MAX : (((u64)1) << info.nb_tx_ts) - 1;
1235 	rx_ts_assigned_mask = info.nb_rx_ts == 64 ? U64_MAX : (((u64)1) << info.nb_rx_ts) - 1;
1236 
1237 	list_for_each_entry(chan, &qmc->chan_head, list) {
1238 		if (chan->tx_ts_mask_avail > tx_ts_assigned_mask) {
1239 			dev_err(qmc->dev, "chan %u can use TSA unassigned Tx TS\n", chan->id);
1240 			return -EINVAL;
1241 		}
1242 
1243 		if (chan->rx_ts_mask_avail > rx_ts_assigned_mask) {
1244 			dev_err(qmc->dev, "chan %u can use TSA unassigned Rx TS\n", chan->id);
1245 			return -EINVAL;
1246 		}
1247 	}
1248 
1249 	return 0;
1250 }
1251 
1252 static unsigned int qmc_nb_chans(struct qmc *qmc)
1253 {
1254 	unsigned int count = 0;
1255 	struct qmc_chan *chan;
1256 
1257 	list_for_each_entry(chan, &qmc->chan_head, list)
1258 		count++;
1259 
1260 	return count;
1261 }
1262 
1263 static int qmc_of_parse_chans(struct qmc *qmc, struct device_node *np)
1264 {
1265 	struct device_node *chan_np;
1266 	struct qmc_chan *chan;
1267 	const char *mode;
1268 	u32 chan_id;
1269 	u64 ts_mask;
1270 	int ret;
1271 
1272 	for_each_available_child_of_node(np, chan_np) {
1273 		ret = of_property_read_u32(chan_np, "reg", &chan_id);
1274 		if (ret) {
1275 			dev_err(qmc->dev, "%pOF: failed to read reg\n", chan_np);
1276 			of_node_put(chan_np);
1277 			return ret;
1278 		}
1279 		if (chan_id > 63) {
1280 			dev_err(qmc->dev, "%pOF: Invalid chan_id\n", chan_np);
1281 			of_node_put(chan_np);
1282 			return -EINVAL;
1283 		}
1284 
1285 		chan = devm_kzalloc(qmc->dev, sizeof(*chan), GFP_KERNEL);
1286 		if (!chan) {
1287 			of_node_put(chan_np);
1288 			return -ENOMEM;
1289 		}
1290 
1291 		chan->id = chan_id;
1292 		spin_lock_init(&chan->ts_lock);
1293 		spin_lock_init(&chan->rx_lock);
1294 		spin_lock_init(&chan->tx_lock);
1295 
1296 		ret = of_property_read_u64(chan_np, "fsl,tx-ts-mask", &ts_mask);
1297 		if (ret) {
1298 			dev_err(qmc->dev, "%pOF: failed to read fsl,tx-ts-mask\n",
1299 				chan_np);
1300 			of_node_put(chan_np);
1301 			return ret;
1302 		}
1303 		chan->tx_ts_mask_avail = ts_mask;
1304 		chan->tx_ts_mask = chan->tx_ts_mask_avail;
1305 
1306 		ret = of_property_read_u64(chan_np, "fsl,rx-ts-mask", &ts_mask);
1307 		if (ret) {
1308 			dev_err(qmc->dev, "%pOF: failed to read fsl,rx-ts-mask\n",
1309 				chan_np);
1310 			of_node_put(chan_np);
1311 			return ret;
1312 		}
1313 		chan->rx_ts_mask_avail = ts_mask;
1314 		chan->rx_ts_mask = chan->rx_ts_mask_avail;
1315 
1316 		mode = "transparent";
1317 		ret = of_property_read_string(chan_np, "fsl,operational-mode", &mode);
1318 		if (ret && ret != -EINVAL) {
1319 			dev_err(qmc->dev, "%pOF: failed to read fsl,operational-mode\n",
1320 				chan_np);
1321 			of_node_put(chan_np);
1322 			return ret;
1323 		}
1324 		if (!strcmp(mode, "transparent")) {
1325 			chan->mode = QMC_TRANSPARENT;
1326 		} else if (!strcmp(mode, "hdlc")) {
1327 			chan->mode = QMC_HDLC;
1328 		} else {
1329 			dev_err(qmc->dev, "%pOF: Invalid fsl,operational-mode (%s)\n",
1330 				chan_np, mode);
1331 			of_node_put(chan_np);
1332 			return -EINVAL;
1333 		}
1334 
1335 		chan->is_reverse_data = of_property_read_bool(chan_np,
1336 							      "fsl,reverse-data");
1337 
1338 		list_add_tail(&chan->list, &qmc->chan_head);
1339 		qmc->chans[chan->id] = chan;
1340 	}
1341 
1342 	return qmc_check_chans(qmc);
1343 }
1344 
1345 static int qmc_init_tsa_64rxtx(struct qmc *qmc, const struct tsa_serial_info *info)
1346 {
1347 	unsigned int i;
1348 	u16 val;
1349 
1350 	/*
1351 	 * Use a common Tx/Rx 64 entries table.
1352 	 * Everything was previously checked, Tx and Rx related stuffs are
1353 	 * identical -> Used Rx related stuff to build the table
1354 	 */
1355 	qmc->is_tsa_64rxtx = true;
1356 
1357 	/* Invalidate all entries */
1358 	for (i = 0; i < 64; i++)
1359 		qmc_write16(qmc->scc_pram + QMC_GBL_TSATRX + (i * 2), 0x0000);
1360 
1361 	/* Set Wrap bit on last entry */
1362 	qmc_setbits16(qmc->scc_pram + QMC_GBL_TSATRX + ((info->nb_rx_ts - 1) * 2),
1363 		      QMC_TSA_WRAP);
1364 
1365 	/* Init pointers to the table */
1366 	val = qmc->scc_pram_offset + QMC_GBL_TSATRX;
1367 	qmc_write16(qmc->scc_pram + QMC_GBL_RX_S_PTR, val);
1368 	qmc_write16(qmc->scc_pram + QMC_GBL_RXPTR, val);
1369 	qmc_write16(qmc->scc_pram + QMC_GBL_TX_S_PTR, val);
1370 	qmc_write16(qmc->scc_pram + QMC_GBL_TXPTR, val);
1371 
1372 	return 0;
1373 }
1374 
1375 static int qmc_init_tsa_32rx_32tx(struct qmc *qmc, const struct tsa_serial_info *info)
1376 {
1377 	unsigned int i;
1378 	u16 val;
1379 
1380 	/*
1381 	 * Use a Tx 32 entries table and a Rx 32 entries table.
1382 	 * Everything was previously checked.
1383 	 */
1384 	qmc->is_tsa_64rxtx = false;
1385 
1386 	/* Invalidate all entries */
1387 	for (i = 0; i < 32; i++) {
1388 		qmc_write16(qmc->scc_pram + QMC_GBL_TSATRX + (i * 2), 0x0000);
1389 		qmc_write16(qmc->scc_pram + QMC_GBL_TSATTX + (i * 2), 0x0000);
1390 	}
1391 
1392 	/* Set Wrap bit on last entries */
1393 	qmc_setbits16(qmc->scc_pram + QMC_GBL_TSATRX + ((info->nb_rx_ts - 1) * 2),
1394 		      QMC_TSA_WRAP);
1395 	qmc_setbits16(qmc->scc_pram + QMC_GBL_TSATTX + ((info->nb_tx_ts - 1) * 2),
1396 		      QMC_TSA_WRAP);
1397 
1398 	/* Init Rx pointers ...*/
1399 	val = qmc->scc_pram_offset + QMC_GBL_TSATRX;
1400 	qmc_write16(qmc->scc_pram + QMC_GBL_RX_S_PTR, val);
1401 	qmc_write16(qmc->scc_pram + QMC_GBL_RXPTR, val);
1402 
1403 	/* ... and Tx pointers */
1404 	val = qmc->scc_pram_offset + QMC_GBL_TSATTX;
1405 	qmc_write16(qmc->scc_pram + QMC_GBL_TX_S_PTR, val);
1406 	qmc_write16(qmc->scc_pram + QMC_GBL_TXPTR, val);
1407 
1408 	return 0;
1409 }
1410 
1411 static int qmc_init_tsa(struct qmc *qmc)
1412 {
1413 	struct tsa_serial_info info;
1414 	int ret;
1415 
1416 	/* Retrieve info from the TSA related serial */
1417 	ret = tsa_serial_get_info(qmc->tsa_serial, &info);
1418 	if (ret)
1419 		return ret;
1420 
1421 	/*
1422 	 * Initialize one common 64 entries table or two 32 entries (one for Tx
1423 	 * and one for Tx) according to assigned TS numbers.
1424 	 */
1425 	return ((info.nb_tx_ts > 32) || (info.nb_rx_ts > 32)) ?
1426 		qmc_init_tsa_64rxtx(qmc, &info) :
1427 		qmc_init_tsa_32rx_32tx(qmc, &info);
1428 }
1429 
1430 static int qmc_setup_chan(struct qmc *qmc, struct qmc_chan *chan)
1431 {
1432 	unsigned int i;
1433 	cbd_t __iomem *bd;
1434 	int ret;
1435 	u16 val;
1436 
1437 	chan->qmc = qmc;
1438 
1439 	/* Set channel specific parameter base address */
1440 	chan->s_param = qmc->dpram + (chan->id * 64);
1441 	/* 16 bd per channel (8 rx and 8 tx) */
1442 	chan->txbds = qmc->bd_table + (chan->id * (QMC_NB_TXBDS + QMC_NB_RXBDS));
1443 	chan->rxbds = qmc->bd_table + (chan->id * (QMC_NB_TXBDS + QMC_NB_RXBDS)) + QMC_NB_TXBDS;
1444 
1445 	chan->txbd_free = chan->txbds;
1446 	chan->txbd_done = chan->txbds;
1447 	chan->rxbd_free = chan->rxbds;
1448 	chan->rxbd_done = chan->rxbds;
1449 
1450 	/* TBASE and TBPTR*/
1451 	val = chan->id * (QMC_NB_TXBDS + QMC_NB_RXBDS) * sizeof(cbd_t);
1452 	qmc_write16(chan->s_param + QMC_SPE_TBASE, val);
1453 	qmc_write16(chan->s_param + QMC_SPE_TBPTR, val);
1454 
1455 	/* RBASE and RBPTR*/
1456 	val = ((chan->id * (QMC_NB_TXBDS + QMC_NB_RXBDS)) + QMC_NB_TXBDS) * sizeof(cbd_t);
1457 	qmc_write16(chan->s_param + QMC_SPE_RBASE, val);
1458 	qmc_write16(chan->s_param + QMC_SPE_RBPTR, val);
1459 	qmc_write32(chan->s_param + QMC_SPE_TSTATE, chan->qmc->data->tstate);
1460 	qmc_write32(chan->s_param + QMC_SPE_RSTATE, chan->qmc->data->rstate);
1461 	qmc_write32(chan->s_param + QMC_SPE_ZISTATE, chan->qmc->data->zistate);
1462 	qmc_write32(chan->s_param + QMC_SPE_RPACK, chan->qmc->data->rpack);
1463 	if (chan->mode == QMC_TRANSPARENT) {
1464 		qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, chan->qmc->data->zdstate_transp);
1465 		qmc_write16(chan->s_param + QMC_SPE_TMRBLR, 60);
1466 		val = QMC_SPE_CHAMR_MODE_TRANSP;
1467 		if (chan->is_reverse_data)
1468 			val |= QMC_SPE_CHAMR_TRANSP_RD;
1469 		qmc_write16(chan->s_param + QMC_SPE_CHAMR, val);
1470 		ret = qmc_setup_chan_trnsync(qmc, chan);
1471 		if (ret)
1472 			return ret;
1473 	} else {
1474 		qmc_write32(chan->s_param + QMC_SPE_ZDSTATE, chan->qmc->data->zdstate_hdlc);
1475 		qmc_write16(chan->s_param + QMC_SPE_MFLR, 60);
1476 		qmc_write16(chan->s_param + QMC_SPE_CHAMR,
1477 			    QMC_SPE_CHAMR_MODE_HDLC | QMC_SPE_CHAMR_HDLC_IDLM);
1478 	}
1479 
1480 	/* Do not enable interrupts now. They will be enabled later */
1481 	qmc_write16(chan->s_param + QMC_SPE_INTMSK, 0x0000);
1482 
1483 	/* Init Rx BDs and set Wrap bit on last descriptor */
1484 	BUILD_BUG_ON(QMC_NB_RXBDS == 0);
1485 	val = QMC_BD_RX_I;
1486 	for (i = 0; i < QMC_NB_RXBDS; i++) {
1487 		bd = chan->rxbds + i;
1488 		qmc_write16(&bd->cbd_sc, val);
1489 	}
1490 	bd = chan->rxbds + QMC_NB_RXBDS - 1;
1491 	qmc_write16(&bd->cbd_sc, val | QMC_BD_RX_W);
1492 
1493 	/* Init Tx BDs and set Wrap bit on last descriptor */
1494 	BUILD_BUG_ON(QMC_NB_TXBDS == 0);
1495 	val = QMC_BD_TX_I;
1496 	if (chan->mode == QMC_HDLC)
1497 		val |= QMC_BD_TX_L | QMC_BD_TX_TC;
1498 	for (i = 0; i < QMC_NB_TXBDS; i++) {
1499 		bd = chan->txbds + i;
1500 		qmc_write16(&bd->cbd_sc, val);
1501 	}
1502 	bd = chan->txbds + QMC_NB_TXBDS - 1;
1503 	qmc_write16(&bd->cbd_sc, val | QMC_BD_TX_W);
1504 
1505 	return 0;
1506 }
1507 
1508 static int qmc_setup_chans(struct qmc *qmc)
1509 {
1510 	struct qmc_chan *chan;
1511 	int ret;
1512 
1513 	list_for_each_entry(chan, &qmc->chan_head, list) {
1514 		ret = qmc_setup_chan(qmc, chan);
1515 		if (ret)
1516 			return ret;
1517 	}
1518 
1519 	return 0;
1520 }
1521 
1522 static int qmc_finalize_chans(struct qmc *qmc)
1523 {
1524 	struct qmc_chan *chan;
1525 	int ret;
1526 
1527 	list_for_each_entry(chan, &qmc->chan_head, list) {
1528 		/* Unmask channel interrupts */
1529 		if (chan->mode == QMC_HDLC) {
1530 			qmc_write16(chan->s_param + QMC_SPE_INTMSK,
1531 				    QMC_INT_NID | QMC_INT_IDL | QMC_INT_MRF |
1532 				    QMC_INT_UN | QMC_INT_RXF | QMC_INT_BSY |
1533 				    QMC_INT_TXB | QMC_INT_RXB);
1534 		} else {
1535 			qmc_write16(chan->s_param + QMC_SPE_INTMSK,
1536 				    QMC_INT_UN | QMC_INT_BSY |
1537 				    QMC_INT_TXB | QMC_INT_RXB);
1538 		}
1539 
1540 		/* Forced stop the channel */
1541 		ret = qmc_chan_stop(chan, QMC_CHAN_ALL);
1542 		if (ret)
1543 			return ret;
1544 	}
1545 
1546 	return 0;
1547 }
1548 
1549 static int qmc_setup_ints(struct qmc *qmc)
1550 {
1551 	unsigned int i;
1552 	u16 __iomem *last;
1553 
1554 	/* Raz all entries */
1555 	for (i = 0; i < (qmc->int_size / sizeof(u16)); i++)
1556 		qmc_write16(qmc->int_table + i, 0x0000);
1557 
1558 	/* Set Wrap bit on last entry */
1559 	if (qmc->int_size >= sizeof(u16)) {
1560 		last = qmc->int_table + (qmc->int_size / sizeof(u16)) - 1;
1561 		qmc_write16(last, QMC_INT_W);
1562 	}
1563 
1564 	return 0;
1565 }
1566 
1567 static void qmc_irq_gint(struct qmc *qmc)
1568 {
1569 	struct qmc_chan *chan;
1570 	unsigned int chan_id;
1571 	unsigned long flags;
1572 	u16 int_entry;
1573 
1574 	int_entry = qmc_read16(qmc->int_curr);
1575 	while (int_entry & QMC_INT_V) {
1576 		/* Clear all but the Wrap bit */
1577 		qmc_write16(qmc->int_curr, int_entry & QMC_INT_W);
1578 
1579 		chan_id = QMC_INT_GET_CHANNEL(int_entry);
1580 		chan = qmc->chans[chan_id];
1581 		if (!chan) {
1582 			dev_err(qmc->dev, "interrupt on invalid chan %u\n", chan_id);
1583 			goto int_next;
1584 		}
1585 
1586 		if (int_entry & QMC_INT_TXB)
1587 			qmc_chan_write_done(chan);
1588 
1589 		if (int_entry & QMC_INT_UN) {
1590 			dev_info(qmc->dev, "intr chan %u, 0x%04x (UN)\n", chan_id,
1591 				 int_entry);
1592 			chan->nb_tx_underrun++;
1593 		}
1594 
1595 		if (int_entry & QMC_INT_BSY) {
1596 			dev_info(qmc->dev, "intr chan %u, 0x%04x (BSY)\n", chan_id,
1597 				 int_entry);
1598 			chan->nb_rx_busy++;
1599 			/* Restart the receiver if needed */
1600 			spin_lock_irqsave(&chan->rx_lock, flags);
1601 			if (chan->rx_pending && !chan->is_rx_stopped) {
1602 				qmc_write32(chan->s_param + QMC_SPE_RPACK,
1603 					    chan->qmc->data->rpack);
1604 				qmc_write32(chan->s_param + QMC_SPE_ZDSTATE,
1605 					    chan->mode == QMC_TRANSPARENT ?
1606 						chan->qmc->data->zdstate_transp :
1607 						chan->qmc->data->zdstate_hdlc);
1608 				qmc_write32(chan->s_param + QMC_SPE_RSTATE,
1609 					    chan->qmc->data->rstate);
1610 				chan->is_rx_halted = false;
1611 			} else {
1612 				chan->is_rx_halted = true;
1613 			}
1614 			spin_unlock_irqrestore(&chan->rx_lock, flags);
1615 		}
1616 
1617 		if (int_entry & QMC_INT_RXB)
1618 			qmc_chan_read_done(chan);
1619 
1620 int_next:
1621 		if (int_entry & QMC_INT_W)
1622 			qmc->int_curr = qmc->int_table;
1623 		else
1624 			qmc->int_curr++;
1625 		int_entry = qmc_read16(qmc->int_curr);
1626 	}
1627 }
1628 
1629 static irqreturn_t qmc_irq_handler(int irq, void *priv)
1630 {
1631 	struct qmc *qmc = (struct qmc *)priv;
1632 	u16 scce;
1633 
1634 	scce = qmc_read16(qmc->scc_regs + SCC_SCCE);
1635 	qmc_write16(qmc->scc_regs + SCC_SCCE, scce);
1636 
1637 	if (unlikely(scce & SCC_SCCE_IQOV))
1638 		dev_info(qmc->dev, "IRQ queue overflow\n");
1639 
1640 	if (unlikely(scce & SCC_SCCE_GUN))
1641 		dev_err(qmc->dev, "Global transmitter underrun\n");
1642 
1643 	if (unlikely(scce & SCC_SCCE_GOV))
1644 		dev_err(qmc->dev, "Global receiver overrun\n");
1645 
1646 	/* normal interrupt */
1647 	if (likely(scce & SCC_SCCE_GINT))
1648 		qmc_irq_gint(qmc);
1649 
1650 	return IRQ_HANDLED;
1651 }
1652 
1653 static int qmc_qe_soft_qmc_init(struct qmc *qmc, struct device_node *np)
1654 {
1655 	struct qe_firmware_info *qe_fw_info;
1656 	const struct qe_firmware *qe_fw;
1657 	const struct firmware *fw;
1658 	const char *filename;
1659 	int ret;
1660 
1661 	ret = of_property_read_string(np, "fsl,soft-qmc", &filename);
1662 	switch (ret) {
1663 	case 0:
1664 		break;
1665 	case -EINVAL:
1666 		/* fsl,soft-qmc property not set -> Simply do nothing */
1667 		return 0;
1668 	default:
1669 		dev_err(qmc->dev, "%pOF: failed to read fsl,soft-qmc\n",
1670 			np);
1671 		return ret;
1672 	}
1673 
1674 	qe_fw_info = qe_get_firmware_info();
1675 	if (qe_fw_info) {
1676 		if (!strstr(qe_fw_info->id, "Soft-QMC")) {
1677 			dev_err(qmc->dev, "Another Firmware is already loaded\n");
1678 			return -EALREADY;
1679 		}
1680 		dev_info(qmc->dev, "Firmware already loaded\n");
1681 		return 0;
1682 	}
1683 
1684 	dev_info(qmc->dev, "Using firmware %s\n", filename);
1685 
1686 	ret = request_firmware(&fw, filename, qmc->dev);
1687 	if (ret) {
1688 		dev_err(qmc->dev, "Failed to request firmware %s\n", filename);
1689 		return ret;
1690 	}
1691 
1692 	qe_fw = (const struct qe_firmware *)fw->data;
1693 
1694 	if (fw->size < sizeof(qe_fw->header) ||
1695 	    be32_to_cpu(qe_fw->header.length) != fw->size) {
1696 		dev_err(qmc->dev, "Invalid firmware %s\n", filename);
1697 		ret = -EINVAL;
1698 		goto end;
1699 	}
1700 
1701 	ret = qe_upload_firmware(qe_fw);
1702 	if (ret) {
1703 		dev_err(qmc->dev, "Failed to load firmware %s\n", filename);
1704 		goto end;
1705 	}
1706 
1707 	ret = 0;
1708 end:
1709 	release_firmware(fw);
1710 	return ret;
1711 }
1712 
1713 static int qmc_cpm1_init_resources(struct qmc *qmc, struct platform_device *pdev)
1714 {
1715 	struct resource *res;
1716 
1717 	qmc->scc_regs = devm_platform_ioremap_resource_byname(pdev, "scc_regs");
1718 	if (IS_ERR(qmc->scc_regs))
1719 		return PTR_ERR(qmc->scc_regs);
1720 
1721 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "scc_pram");
1722 	if (!res)
1723 		return -EINVAL;
1724 	qmc->scc_pram_offset = res->start - get_immrbase();
1725 	qmc->scc_pram = devm_ioremap_resource(qmc->dev, res);
1726 	if (IS_ERR(qmc->scc_pram))
1727 		return PTR_ERR(qmc->scc_pram);
1728 
1729 	qmc->dpram  = devm_platform_ioremap_resource_byname(pdev, "dpram");
1730 	if (IS_ERR(qmc->dpram))
1731 		return PTR_ERR(qmc->dpram);
1732 
1733 	return 0;
1734 }
1735 
1736 static int qmc_qe_init_resources(struct qmc *qmc, struct platform_device *pdev)
1737 {
1738 	struct resource *res;
1739 	int ucc_num;
1740 	s32 info;
1741 
1742 	qmc->scc_regs = devm_platform_ioremap_resource_byname(pdev, "ucc_regs");
1743 	if (IS_ERR(qmc->scc_regs))
1744 		return PTR_ERR(qmc->scc_regs);
1745 
1746 	ucc_num = tsa_serial_get_num(qmc->tsa_serial);
1747 	if (ucc_num < 0)
1748 		return dev_err_probe(qmc->dev, ucc_num, "Failed to get UCC num\n");
1749 
1750 	qmc->qe_subblock = ucc_slow_get_qe_cr_subblock(ucc_num);
1751 	if (qmc->qe_subblock == QE_CR_SUBBLOCK_INVALID) {
1752 		dev_err(qmc->dev, "Unsupported ucc num %u\n", ucc_num);
1753 		return -EINVAL;
1754 	}
1755 	/* Allocate the 'Global Multichannel Parameters' and the
1756 	 * 'Framer parameters' areas. The 'Framer parameters' area
1757 	 * is located right after the 'Global Multichannel Parameters'.
1758 	 * The 'Framer parameters' need 1 byte per receive and transmit
1759 	 * channel. The maximum number of receive or transmit channel
1760 	 * is 64. So reserve 2 * 64 bytes for the 'Framer parameters'.
1761 	 */
1762 	info = devm_qe_muram_alloc(qmc->dev, UCC_SLOW_PRAM_SIZE + 2 * 64,
1763 				   ALIGNMENT_OF_UCC_SLOW_PRAM);
1764 	if (info < 0)
1765 		return info;
1766 
1767 	if (!qe_issue_cmd(QE_ASSIGN_PAGE_TO_DEVICE, qmc->qe_subblock,
1768 			  QE_CR_PROTOCOL_UNSPECIFIED, info)) {
1769 		dev_err(qmc->dev, "QE_ASSIGN_PAGE_TO_DEVICE cmd failed");
1770 		return -EIO;
1771 	}
1772 	qmc->scc_pram = qe_muram_addr(info);
1773 	qmc->scc_pram_offset = info;
1774 
1775 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dpram");
1776 	if (!res)
1777 		return -EINVAL;
1778 	qmc->dpram_offset = res->start - qe_muram_dma(qe_muram_addr(0));
1779 	qmc->dpram = devm_ioremap_resource(qmc->dev, res);
1780 	if (IS_ERR(qmc->scc_pram))
1781 		return PTR_ERR(qmc->scc_pram);
1782 
1783 	return 0;
1784 }
1785 
1786 static int qmc_init_resources(struct qmc *qmc, struct platform_device *pdev)
1787 {
1788 	return qmc_is_qe(qmc) ?
1789 		qmc_qe_init_resources(qmc, pdev) :
1790 		qmc_cpm1_init_resources(qmc, pdev);
1791 }
1792 
1793 static int qmc_cpm1_init_scc(struct qmc *qmc)
1794 {
1795 	u32 val;
1796 	int ret;
1797 
1798 	/* Connect the serial (SCC) to TSA */
1799 	ret = tsa_serial_connect(qmc->tsa_serial);
1800 	if (ret)
1801 		return dev_err_probe(qmc->dev, ret, "Failed to connect TSA serial\n");
1802 
1803 	/* Init GMSR_H and GMSR_L registers */
1804 	val = SCC_GSMRH_CDS | SCC_GSMRH_CTSS | SCC_GSMRH_CDP | SCC_GSMRH_CTSP;
1805 	qmc_write32(qmc->scc_regs + SCC_GSMRH, val);
1806 
1807 	/* enable QMC mode */
1808 	qmc_write32(qmc->scc_regs + SCC_GSMRL, SCC_CPM1_GSMRL_MODE_QMC);
1809 
1810 	/* Disable and clear interrupts */
1811 	qmc_write16(qmc->scc_regs + SCC_SCCM, 0x0000);
1812 	qmc_write16(qmc->scc_regs + SCC_SCCE, 0x000F);
1813 
1814 	return 0;
1815 }
1816 
1817 static int qmc_qe_init_ucc(struct qmc *qmc)
1818 {
1819 	u32 val;
1820 	int ret;
1821 
1822 	/* Set the UCC in slow mode */
1823 	qmc_write8(qmc->scc_regs + SCC_QE_UCC_GUEMR,
1824 		   UCC_GUEMR_SET_RESERVED3 | UCC_GUEMR_MODE_SLOW_RX | UCC_GUEMR_MODE_SLOW_TX);
1825 
1826 	/* Connect the serial (UCC) to TSA */
1827 	ret = tsa_serial_connect(qmc->tsa_serial);
1828 	if (ret)
1829 		return dev_err_probe(qmc->dev, ret, "Failed to connect TSA serial\n");
1830 
1831 	/* Initialize the QMC tx startup addresses */
1832 	if (!qe_issue_cmd(QE_PUSHSCHED, qmc->qe_subblock,
1833 			  QE_CR_PROTOCOL_UNSPECIFIED, 0x80)) {
1834 		dev_err(qmc->dev, "QE_CMD_PUSH_SCHED tx cmd failed");
1835 		ret = -EIO;
1836 		goto err_tsa_serial_disconnect;
1837 	}
1838 
1839 	/* Initialize the QMC rx startup addresses */
1840 	if (!qe_issue_cmd(QE_PUSHSCHED, qmc->qe_subblock | 0x00020000,
1841 			  QE_CR_PROTOCOL_UNSPECIFIED, 0x82)) {
1842 		dev_err(qmc->dev, "QE_CMD_PUSH_SCHED rx cmd failed");
1843 		ret = -EIO;
1844 		goto err_tsa_serial_disconnect;
1845 	}
1846 
1847 	/* Re-init RXPTR and TXPTR with the content of RX_S_PTR and
1848 	 * TX_S_PTR (RX_S_PTR and TX_S_PTR are initialized during
1849 	 * qmc_setup_tsa() call
1850 	 */
1851 	val = qmc_read16(qmc->scc_pram + QMC_GBL_RX_S_PTR);
1852 	qmc_write16(qmc->scc_pram + QMC_GBL_RXPTR, val);
1853 	val = qmc_read16(qmc->scc_pram + QMC_GBL_TX_S_PTR);
1854 	qmc_write16(qmc->scc_pram + QMC_GBL_TXPTR, val);
1855 
1856 	/* Init GUMR_H and GUMR_L registers (SCC GSMR_H and GSMR_L) */
1857 	val = SCC_GSMRH_CDS | SCC_GSMRH_CTSS | SCC_GSMRH_CDP | SCC_GSMRH_CTSP |
1858 	      SCC_GSMRH_TRX | SCC_GSMRH_TTX;
1859 	qmc_write32(qmc->scc_regs + SCC_GSMRH, val);
1860 
1861 	/* enable QMC mode */
1862 	qmc_write32(qmc->scc_regs + SCC_GSMRL, SCC_QE_GSMRL_MODE_QMC);
1863 
1864 	/* Disable and clear interrupts */
1865 	qmc_write16(qmc->scc_regs + SCC_SCCM, 0x0000);
1866 	qmc_write16(qmc->scc_regs + SCC_SCCE, 0x000F);
1867 
1868 	return 0;
1869 
1870 err_tsa_serial_disconnect:
1871 	tsa_serial_disconnect(qmc->tsa_serial);
1872 	return ret;
1873 }
1874 
1875 static int qmc_init_xcc(struct qmc *qmc)
1876 {
1877 	return qmc_is_qe(qmc) ?
1878 		qmc_qe_init_ucc(qmc) :
1879 		qmc_cpm1_init_scc(qmc);
1880 }
1881 
1882 static void qmc_exit_xcc(struct qmc *qmc)
1883 {
1884 	/* Disconnect the serial from TSA */
1885 	tsa_serial_disconnect(qmc->tsa_serial);
1886 }
1887 
1888 static int qmc_probe(struct platform_device *pdev)
1889 {
1890 	struct device_node *np = pdev->dev.of_node;
1891 	unsigned int nb_chans;
1892 	struct qmc *qmc;
1893 	int irq;
1894 	int ret;
1895 
1896 	qmc = devm_kzalloc(&pdev->dev, sizeof(*qmc), GFP_KERNEL);
1897 	if (!qmc)
1898 		return -ENOMEM;
1899 
1900 	qmc->dev = &pdev->dev;
1901 	qmc->data = of_device_get_match_data(&pdev->dev);
1902 	if (!qmc->data) {
1903 		dev_err(qmc->dev, "Missing match data\n");
1904 		return -EINVAL;
1905 	}
1906 	INIT_LIST_HEAD(&qmc->chan_head);
1907 
1908 	qmc->tsa_serial = devm_tsa_serial_get_byphandle(qmc->dev, np, "fsl,tsa-serial");
1909 	if (IS_ERR(qmc->tsa_serial)) {
1910 		return dev_err_probe(qmc->dev, PTR_ERR(qmc->tsa_serial),
1911 				     "Failed to get TSA serial\n");
1912 	}
1913 
1914 	ret = qmc_init_resources(qmc, pdev);
1915 	if (ret)
1916 		return ret;
1917 
1918 	if (qmc_is_qe(qmc)) {
1919 		ret = qmc_qe_soft_qmc_init(qmc, np);
1920 		if (ret)
1921 			return ret;
1922 	}
1923 
1924 	/* Parse channels informationss */
1925 	ret = qmc_of_parse_chans(qmc, np);
1926 	if (ret)
1927 		return ret;
1928 
1929 	nb_chans = qmc_nb_chans(qmc);
1930 
1931 	/*
1932 	 * Allocate the buffer descriptor table
1933 	 * 8 rx and 8 tx descriptors per channel
1934 	 */
1935 	qmc->bd_size = (nb_chans * (QMC_NB_TXBDS + QMC_NB_RXBDS)) * sizeof(cbd_t);
1936 	qmc->bd_table = dmam_alloc_coherent(qmc->dev, qmc->bd_size,
1937 					    &qmc->bd_dma_addr, GFP_KERNEL);
1938 	if (!qmc->bd_table) {
1939 		dev_err(qmc->dev, "Failed to allocate bd table\n");
1940 		return -ENOMEM;
1941 	}
1942 	memset(qmc->bd_table, 0, qmc->bd_size);
1943 
1944 	qmc_write32(qmc->scc_pram + QMC_GBL_MCBASE, qmc->bd_dma_addr);
1945 
1946 	/* Allocate the interrupt table */
1947 	qmc->int_size = QMC_NB_INTS * sizeof(u16);
1948 	qmc->int_table = dmam_alloc_coherent(qmc->dev, qmc->int_size,
1949 					     &qmc->int_dma_addr, GFP_KERNEL);
1950 	if (!qmc->int_table) {
1951 		dev_err(qmc->dev, "Failed to allocate interrupt table\n");
1952 		return -ENOMEM;
1953 	}
1954 	memset(qmc->int_table, 0, qmc->int_size);
1955 
1956 	qmc->int_curr = qmc->int_table;
1957 	qmc_write32(qmc->scc_pram + QMC_GBL_INTBASE, qmc->int_dma_addr);
1958 	qmc_write32(qmc->scc_pram + QMC_GBL_INTPTR, qmc->int_dma_addr);
1959 
1960 	/* Set MRBLR (valid for HDLC only) max MRU + max CRC */
1961 	qmc_write16(qmc->scc_pram + QMC_GBL_MRBLR, HDLC_MAX_MRU + 4);
1962 
1963 	qmc_write16(qmc->scc_pram + QMC_GBL_GRFTHR, 1);
1964 	qmc_write16(qmc->scc_pram + QMC_GBL_GRFCNT, 1);
1965 
1966 	qmc_write32(qmc->scc_pram + QMC_GBL_C_MASK32, 0xDEBB20E3);
1967 	qmc_write16(qmc->scc_pram + QMC_GBL_C_MASK16, 0xF0B8);
1968 
1969 	if (qmc_is_qe(qmc)) {
1970 		/* Zeroed the reserved area */
1971 		memset_io(qmc->scc_pram + QMC_QE_GBL_RSV_B0_START, 0,
1972 			  QMC_QE_GBL_RSV_B0_SIZE);
1973 
1974 		qmc_write32(qmc->scc_pram + QMC_QE_GBL_GCSBASE, qmc->dpram_offset);
1975 
1976 		/* Init 'framer parameters' area and set the base addresses */
1977 		memset_io(qmc->scc_pram + UCC_SLOW_PRAM_SIZE, 0x01, 64);
1978 		memset_io(qmc->scc_pram + UCC_SLOW_PRAM_SIZE + 64, 0x01, 64);
1979 		qmc_write16(qmc->scc_pram + QMC_QE_GBL_RX_FRM_BASE,
1980 			    qmc->scc_pram_offset + UCC_SLOW_PRAM_SIZE);
1981 		qmc_write16(qmc->scc_pram + QMC_QE_GBL_TX_FRM_BASE,
1982 			    qmc->scc_pram_offset + UCC_SLOW_PRAM_SIZE + 64);
1983 	}
1984 
1985 	ret = qmc_init_tsa(qmc);
1986 	if (ret)
1987 		return ret;
1988 
1989 	qmc_write16(qmc->scc_pram + QMC_GBL_QMCSTATE, 0x8000);
1990 
1991 	ret = qmc_setup_chans(qmc);
1992 	if (ret)
1993 		return ret;
1994 
1995 	/* Init interrupts table */
1996 	ret = qmc_setup_ints(qmc);
1997 	if (ret)
1998 		return ret;
1999 
2000 	/* Init SCC (CPM1) or UCC (QE) */
2001 	ret = qmc_init_xcc(qmc);
2002 	if (ret)
2003 		return ret;
2004 
2005 	/* Set the irq handler */
2006 	irq = platform_get_irq(pdev, 0);
2007 	if (irq < 0)
2008 		goto err_exit_xcc;
2009 	ret = devm_request_irq(qmc->dev, irq, qmc_irq_handler, 0, "qmc", qmc);
2010 	if (ret < 0)
2011 		goto err_exit_xcc;
2012 
2013 	/* Enable interrupts */
2014 	qmc_write16(qmc->scc_regs + SCC_SCCM,
2015 		    SCC_SCCE_IQOV | SCC_SCCE_GINT | SCC_SCCE_GUN | SCC_SCCE_GOV);
2016 
2017 	ret = qmc_finalize_chans(qmc);
2018 	if (ret < 0)
2019 		goto err_disable_intr;
2020 
2021 	/* Enable transmitter and receiver */
2022 	qmc_setbits32(qmc->scc_regs + SCC_GSMRL, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
2023 
2024 	platform_set_drvdata(pdev, qmc);
2025 
2026 	/* Populate channel related devices */
2027 	ret = devm_of_platform_populate(qmc->dev);
2028 	if (ret)
2029 		goto err_disable_txrx;
2030 
2031 	return 0;
2032 
2033 err_disable_txrx:
2034 	qmc_setbits32(qmc->scc_regs + SCC_GSMRL, 0);
2035 
2036 err_disable_intr:
2037 	qmc_write16(qmc->scc_regs + SCC_SCCM, 0);
2038 
2039 err_exit_xcc:
2040 	qmc_exit_xcc(qmc);
2041 	return ret;
2042 }
2043 
2044 static void qmc_remove(struct platform_device *pdev)
2045 {
2046 	struct qmc *qmc = platform_get_drvdata(pdev);
2047 
2048 	/* Disable transmitter and receiver */
2049 	qmc_setbits32(qmc->scc_regs + SCC_GSMRL, 0);
2050 
2051 	/* Disable interrupts */
2052 	qmc_write16(qmc->scc_regs + SCC_SCCM, 0);
2053 
2054 	/* Exit SCC (CPM1) or UCC (QE) */
2055 	qmc_exit_xcc(qmc);
2056 }
2057 
2058 static const struct qmc_data qmc_data_cpm1 __maybe_unused = {
2059 	.version = QMC_CPM1,
2060 	.tstate = 0x30000000,
2061 	.rstate = 0x31000000,
2062 	.zistate = 0x00000100,
2063 	.zdstate_hdlc = 0x00000080,
2064 	.zdstate_transp = 0x18000080,
2065 	.rpack = 0x00000000,
2066 };
2067 
2068 static const struct qmc_data qmc_data_qe __maybe_unused = {
2069 	.version = QMC_QE,
2070 	.tstate = 0x30000000,
2071 	.rstate = 0x30000000,
2072 	.zistate = 0x00000200,
2073 	.zdstate_hdlc = 0x80FFFFE0,
2074 	.zdstate_transp = 0x003FFFE2,
2075 	.rpack = 0x80000000,
2076 };
2077 
2078 static const struct of_device_id qmc_id_table[] = {
2079 #if IS_ENABLED(CONFIG_CPM1)
2080 	{ .compatible = "fsl,cpm1-scc-qmc", .data = &qmc_data_cpm1 },
2081 #endif
2082 #if IS_ENABLED(CONFIG_QUICC_ENGINE)
2083 	{ .compatible = "fsl,qe-ucc-qmc", .data = &qmc_data_qe },
2084 #endif
2085 	{} /* sentinel */
2086 };
2087 MODULE_DEVICE_TABLE(of, qmc_id_table);
2088 
2089 static struct platform_driver qmc_driver = {
2090 	.driver = {
2091 		.name = "fsl-qmc",
2092 		.of_match_table = of_match_ptr(qmc_id_table),
2093 	},
2094 	.probe = qmc_probe,
2095 	.remove_new = qmc_remove,
2096 };
2097 module_platform_driver(qmc_driver);
2098 
2099 static struct qmc_chan *qmc_chan_get_from_qmc(struct device_node *qmc_np, unsigned int chan_index)
2100 {
2101 	struct platform_device *pdev;
2102 	struct qmc_chan *qmc_chan;
2103 	struct qmc *qmc;
2104 
2105 	if (!of_match_node(qmc_driver.driver.of_match_table, qmc_np))
2106 		return ERR_PTR(-EINVAL);
2107 
2108 	pdev = of_find_device_by_node(qmc_np);
2109 	if (!pdev)
2110 		return ERR_PTR(-ENODEV);
2111 
2112 	qmc = platform_get_drvdata(pdev);
2113 	if (!qmc) {
2114 		platform_device_put(pdev);
2115 		return ERR_PTR(-EPROBE_DEFER);
2116 	}
2117 
2118 	if (chan_index >= ARRAY_SIZE(qmc->chans)) {
2119 		platform_device_put(pdev);
2120 		return ERR_PTR(-EINVAL);
2121 	}
2122 
2123 	qmc_chan = qmc->chans[chan_index];
2124 	if (!qmc_chan) {
2125 		platform_device_put(pdev);
2126 		return ERR_PTR(-ENOENT);
2127 	}
2128 
2129 	return qmc_chan;
2130 }
2131 
2132 int qmc_chan_count_phandles(struct device_node *np, const char *phandles_name)
2133 {
2134 	int count;
2135 
2136 	/* phandles are fixed args phandles with one arg */
2137 	count = of_count_phandle_with_args(np, phandles_name, NULL);
2138 	if (count < 0)
2139 		return count;
2140 
2141 	return count / 2;
2142 }
2143 EXPORT_SYMBOL(qmc_chan_count_phandles);
2144 
2145 struct qmc_chan *qmc_chan_get_byphandles_index(struct device_node *np,
2146 					       const char *phandles_name,
2147 					       int index)
2148 {
2149 	struct of_phandle_args out_args;
2150 	struct qmc_chan *qmc_chan;
2151 	int ret;
2152 
2153 	ret = of_parse_phandle_with_fixed_args(np, phandles_name, 1, index,
2154 					       &out_args);
2155 	if (ret < 0)
2156 		return ERR_PTR(ret);
2157 
2158 	if (out_args.args_count != 1) {
2159 		of_node_put(out_args.np);
2160 		return ERR_PTR(-EINVAL);
2161 	}
2162 
2163 	qmc_chan = qmc_chan_get_from_qmc(out_args.np, out_args.args[0]);
2164 	of_node_put(out_args.np);
2165 	return qmc_chan;
2166 }
2167 EXPORT_SYMBOL(qmc_chan_get_byphandles_index);
2168 
2169 struct qmc_chan *qmc_chan_get_bychild(struct device_node *np)
2170 {
2171 	struct device_node *qmc_np;
2172 	u32 chan_index;
2173 	int ret;
2174 
2175 	qmc_np = np->parent;
2176 	ret = of_property_read_u32(np, "reg", &chan_index);
2177 	if (ret)
2178 		return ERR_PTR(-EINVAL);
2179 
2180 	return qmc_chan_get_from_qmc(qmc_np, chan_index);
2181 }
2182 EXPORT_SYMBOL(qmc_chan_get_bychild);
2183 
2184 void qmc_chan_put(struct qmc_chan *chan)
2185 {
2186 	put_device(chan->qmc->dev);
2187 }
2188 EXPORT_SYMBOL(qmc_chan_put);
2189 
2190 static void devm_qmc_chan_release(struct device *dev, void *res)
2191 {
2192 	struct qmc_chan **qmc_chan = res;
2193 
2194 	qmc_chan_put(*qmc_chan);
2195 }
2196 
2197 struct qmc_chan *devm_qmc_chan_get_byphandles_index(struct device *dev,
2198 						    struct device_node *np,
2199 						    const char *phandles_name,
2200 						    int index)
2201 {
2202 	struct qmc_chan *qmc_chan;
2203 	struct qmc_chan **dr;
2204 
2205 	dr = devres_alloc(devm_qmc_chan_release, sizeof(*dr), GFP_KERNEL);
2206 	if (!dr)
2207 		return ERR_PTR(-ENOMEM);
2208 
2209 	qmc_chan = qmc_chan_get_byphandles_index(np, phandles_name, index);
2210 	if (!IS_ERR(qmc_chan)) {
2211 		*dr = qmc_chan;
2212 		devres_add(dev, dr);
2213 	} else {
2214 		devres_free(dr);
2215 	}
2216 
2217 	return qmc_chan;
2218 }
2219 EXPORT_SYMBOL(devm_qmc_chan_get_byphandles_index);
2220 
2221 struct qmc_chan *devm_qmc_chan_get_bychild(struct device *dev,
2222 					   struct device_node *np)
2223 {
2224 	struct qmc_chan *qmc_chan;
2225 	struct qmc_chan **dr;
2226 
2227 	dr = devres_alloc(devm_qmc_chan_release, sizeof(*dr), GFP_KERNEL);
2228 	if (!dr)
2229 		return ERR_PTR(-ENOMEM);
2230 
2231 	qmc_chan = qmc_chan_get_bychild(np);
2232 	if (!IS_ERR(qmc_chan)) {
2233 		*dr = qmc_chan;
2234 		devres_add(dev, dr);
2235 	} else {
2236 		devres_free(dr);
2237 	}
2238 
2239 	return qmc_chan;
2240 }
2241 EXPORT_SYMBOL(devm_qmc_chan_get_bychild);
2242 
2243 MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
2244 MODULE_DESCRIPTION("CPM/QE QMC driver");
2245 MODULE_LICENSE("GPL");
2246