1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/drivers/mmc/s3cmci.h - Samsung S3C MCI driver
4  *
5  *  Copyright (C) 2004-2006 maintech GmbH, Thomas Kleffel <tk@maintech.de>
6  *
7  * Current driver maintained by Ben Dooks and Simtec Electronics
8  *  Copyright (C) 2008 Simtec Electronics <ben-linux@fluff.org>
9  */
10 
11 #include <linux/module.h>
12 #include <linux/dmaengine.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/clk.h>
15 #include <linux/mmc/host.h>
16 #include <linux/platform_device.h>
17 #include <linux/cpufreq.h>
18 #include <linux/debugfs.h>
19 #include <linux/seq_file.h>
20 #include <linux/gpio/consumer.h>
21 #include <linux/interrupt.h>
22 #include <linux/irq.h>
23 #include <linux/io.h>
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/mmc/slot-gpio.h>
27 #include <linux/platform_data/mmc-s3cmci.h>
28 
29 #include "s3cmci.h"
30 
31 #define DRIVER_NAME "s3c-mci"
32 
33 #define S3C2410_SDICON			(0x00)
34 #define S3C2410_SDIPRE			(0x04)
35 #define S3C2410_SDICMDARG		(0x08)
36 #define S3C2410_SDICMDCON		(0x0C)
37 #define S3C2410_SDICMDSTAT		(0x10)
38 #define S3C2410_SDIRSP0			(0x14)
39 #define S3C2410_SDIRSP1			(0x18)
40 #define S3C2410_SDIRSP2			(0x1C)
41 #define S3C2410_SDIRSP3			(0x20)
42 #define S3C2410_SDITIMER		(0x24)
43 #define S3C2410_SDIBSIZE		(0x28)
44 #define S3C2410_SDIDCON			(0x2C)
45 #define S3C2410_SDIDCNT			(0x30)
46 #define S3C2410_SDIDSTA			(0x34)
47 #define S3C2410_SDIFSTA			(0x38)
48 
49 #define S3C2410_SDIDATA			(0x3C)
50 #define S3C2410_SDIIMSK			(0x40)
51 
52 #define S3C2440_SDIDATA			(0x40)
53 #define S3C2440_SDIIMSK			(0x3C)
54 
55 #define S3C2440_SDICON_SDRESET		(1 << 8)
56 #define S3C2410_SDICON_SDIOIRQ		(1 << 3)
57 #define S3C2410_SDICON_FIFORESET	(1 << 1)
58 #define S3C2410_SDICON_CLOCKTYPE	(1 << 0)
59 
60 #define S3C2410_SDICMDCON_LONGRSP	(1 << 10)
61 #define S3C2410_SDICMDCON_WAITRSP	(1 << 9)
62 #define S3C2410_SDICMDCON_CMDSTART	(1 << 8)
63 #define S3C2410_SDICMDCON_SENDERHOST	(1 << 6)
64 #define S3C2410_SDICMDCON_INDEX		(0x3f)
65 
66 #define S3C2410_SDICMDSTAT_CRCFAIL	(1 << 12)
67 #define S3C2410_SDICMDSTAT_CMDSENT	(1 << 11)
68 #define S3C2410_SDICMDSTAT_CMDTIMEOUT	(1 << 10)
69 #define S3C2410_SDICMDSTAT_RSPFIN	(1 << 9)
70 
71 #define S3C2440_SDIDCON_DS_WORD		(2 << 22)
72 #define S3C2410_SDIDCON_TXAFTERRESP	(1 << 20)
73 #define S3C2410_SDIDCON_RXAFTERCMD	(1 << 19)
74 #define S3C2410_SDIDCON_BLOCKMODE	(1 << 17)
75 #define S3C2410_SDIDCON_WIDEBUS		(1 << 16)
76 #define S3C2410_SDIDCON_DMAEN		(1 << 15)
77 #define S3C2410_SDIDCON_STOP		(1 << 14)
78 #define S3C2440_SDIDCON_DATSTART	(1 << 14)
79 
80 #define S3C2410_SDIDCON_XFER_RXSTART	(2 << 12)
81 #define S3C2410_SDIDCON_XFER_TXSTART	(3 << 12)
82 
83 #define S3C2410_SDIDCON_BLKNUM_MASK	(0xFFF)
84 
85 #define S3C2410_SDIDSTA_SDIOIRQDETECT	(1 << 9)
86 #define S3C2410_SDIDSTA_FIFOFAIL	(1 << 8)
87 #define S3C2410_SDIDSTA_CRCFAIL		(1 << 7)
88 #define S3C2410_SDIDSTA_RXCRCFAIL	(1 << 6)
89 #define S3C2410_SDIDSTA_DATATIMEOUT	(1 << 5)
90 #define S3C2410_SDIDSTA_XFERFINISH	(1 << 4)
91 #define S3C2410_SDIDSTA_TXDATAON	(1 << 1)
92 #define S3C2410_SDIDSTA_RXDATAON	(1 << 0)
93 
94 #define S3C2440_SDIFSTA_FIFORESET	(1 << 16)
95 #define S3C2440_SDIFSTA_FIFOFAIL	(3 << 14)
96 #define S3C2410_SDIFSTA_TFDET		(1 << 13)
97 #define S3C2410_SDIFSTA_RFDET		(1 << 12)
98 #define S3C2410_SDIFSTA_COUNTMASK	(0x7f)
99 
100 #define S3C2410_SDIIMSK_RESPONSECRC	(1 << 17)
101 #define S3C2410_SDIIMSK_CMDSENT		(1 << 16)
102 #define S3C2410_SDIIMSK_CMDTIMEOUT	(1 << 15)
103 #define S3C2410_SDIIMSK_RESPONSEND	(1 << 14)
104 #define S3C2410_SDIIMSK_SDIOIRQ		(1 << 12)
105 #define S3C2410_SDIIMSK_FIFOFAIL	(1 << 11)
106 #define S3C2410_SDIIMSK_CRCSTATUS	(1 << 10)
107 #define S3C2410_SDIIMSK_DATACRC		(1 << 9)
108 #define S3C2410_SDIIMSK_DATATIMEOUT	(1 << 8)
109 #define S3C2410_SDIIMSK_DATAFINISH	(1 << 7)
110 #define S3C2410_SDIIMSK_TXFIFOHALF	(1 << 4)
111 #define S3C2410_SDIIMSK_RXFIFOLAST	(1 << 2)
112 #define S3C2410_SDIIMSK_RXFIFOHALF	(1 << 0)
113 
114 enum dbg_channels {
115 	dbg_err   = (1 << 0),
116 	dbg_debug = (1 << 1),
117 	dbg_info  = (1 << 2),
118 	dbg_irq   = (1 << 3),
119 	dbg_sg    = (1 << 4),
120 	dbg_dma   = (1 << 5),
121 	dbg_pio   = (1 << 6),
122 	dbg_fail  = (1 << 7),
123 	dbg_conf  = (1 << 8),
124 };
125 
126 static const int dbgmap_err   = dbg_fail;
127 static const int dbgmap_info  = dbg_info | dbg_conf;
128 static const int dbgmap_debug = dbg_err | dbg_debug;
129 
130 #define dbg(host, channels, args...)		  \
131 	do {					  \
132 	if (dbgmap_err & channels) 		  \
133 		dev_err(&host->pdev->dev, args);  \
134 	else if (dbgmap_info & channels)	  \
135 		dev_info(&host->pdev->dev, args); \
136 	else if (dbgmap_debug & channels)	  \
137 		dev_dbg(&host->pdev->dev, args);  \
138 	} while (0)
139 
140 static void finalize_request(struct s3cmci_host *host);
141 static void s3cmci_send_request(struct mmc_host *mmc);
142 static void s3cmci_reset(struct s3cmci_host *host);
143 
144 #ifdef CONFIG_MMC_DEBUG
145 
dbg_dumpregs(struct s3cmci_host * host,char * prefix)146 static void dbg_dumpregs(struct s3cmci_host *host, char *prefix)
147 {
148 	u32 con, pre, cmdarg, cmdcon, cmdsta, r0, r1, r2, r3, timer;
149 	u32 datcon, datcnt, datsta, fsta;
150 
151 	con 	= readl(host->base + S3C2410_SDICON);
152 	pre 	= readl(host->base + S3C2410_SDIPRE);
153 	cmdarg 	= readl(host->base + S3C2410_SDICMDARG);
154 	cmdcon 	= readl(host->base + S3C2410_SDICMDCON);
155 	cmdsta 	= readl(host->base + S3C2410_SDICMDSTAT);
156 	r0 	= readl(host->base + S3C2410_SDIRSP0);
157 	r1 	= readl(host->base + S3C2410_SDIRSP1);
158 	r2 	= readl(host->base + S3C2410_SDIRSP2);
159 	r3 	= readl(host->base + S3C2410_SDIRSP3);
160 	timer 	= readl(host->base + S3C2410_SDITIMER);
161 	datcon 	= readl(host->base + S3C2410_SDIDCON);
162 	datcnt 	= readl(host->base + S3C2410_SDIDCNT);
163 	datsta 	= readl(host->base + S3C2410_SDIDSTA);
164 	fsta 	= readl(host->base + S3C2410_SDIFSTA);
165 
166 	dbg(host, dbg_debug, "%s  CON:[%08x]  PRE:[%08x]  TMR:[%08x]\n",
167 				prefix, con, pre, timer);
168 
169 	dbg(host, dbg_debug, "%s CCON:[%08x] CARG:[%08x] CSTA:[%08x]\n",
170 				prefix, cmdcon, cmdarg, cmdsta);
171 
172 	dbg(host, dbg_debug, "%s DCON:[%08x] FSTA:[%08x]"
173 			       " DSTA:[%08x] DCNT:[%08x]\n",
174 				prefix, datcon, fsta, datsta, datcnt);
175 
176 	dbg(host, dbg_debug, "%s   R0:[%08x]   R1:[%08x]"
177 			       "   R2:[%08x]   R3:[%08x]\n",
178 				prefix, r0, r1, r2, r3);
179 }
180 
prepare_dbgmsg(struct s3cmci_host * host,struct mmc_command * cmd,int stop)181 static void prepare_dbgmsg(struct s3cmci_host *host, struct mmc_command *cmd,
182 			   int stop)
183 {
184 	snprintf(host->dbgmsg_cmd, 300,
185 		 "#%u%s op:%i arg:0x%08x flags:0x08%x retries:%u",
186 		 host->ccnt, (stop ? " (STOP)" : ""),
187 		 cmd->opcode, cmd->arg, cmd->flags, cmd->retries);
188 
189 	if (cmd->data) {
190 		snprintf(host->dbgmsg_dat, 300,
191 			 "#%u bsize:%u blocks:%u bytes:%u",
192 			 host->dcnt, cmd->data->blksz,
193 			 cmd->data->blocks,
194 			 cmd->data->blocks * cmd->data->blksz);
195 	} else {
196 		host->dbgmsg_dat[0] = '\0';
197 	}
198 }
199 
dbg_dumpcmd(struct s3cmci_host * host,struct mmc_command * cmd,int fail)200 static void dbg_dumpcmd(struct s3cmci_host *host, struct mmc_command *cmd,
201 			int fail)
202 {
203 	unsigned int dbglvl = fail ? dbg_fail : dbg_debug;
204 
205 	if (!cmd)
206 		return;
207 
208 	if (cmd->error == 0) {
209 		dbg(host, dbglvl, "CMD[OK] %s R0:0x%08x\n",
210 			host->dbgmsg_cmd, cmd->resp[0]);
211 	} else {
212 		dbg(host, dbglvl, "CMD[ERR %i] %s Status:%s\n",
213 			cmd->error, host->dbgmsg_cmd, host->status);
214 	}
215 
216 	if (!cmd->data)
217 		return;
218 
219 	if (cmd->data->error == 0) {
220 		dbg(host, dbglvl, "DAT[OK] %s\n", host->dbgmsg_dat);
221 	} else {
222 		dbg(host, dbglvl, "DAT[ERR %i] %s DCNT:0x%08x\n",
223 			cmd->data->error, host->dbgmsg_dat,
224 			readl(host->base + S3C2410_SDIDCNT));
225 	}
226 }
227 #else
dbg_dumpcmd(struct s3cmci_host * host,struct mmc_command * cmd,int fail)228 static void dbg_dumpcmd(struct s3cmci_host *host,
229 			struct mmc_command *cmd, int fail) { }
230 
prepare_dbgmsg(struct s3cmci_host * host,struct mmc_command * cmd,int stop)231 static void prepare_dbgmsg(struct s3cmci_host *host, struct mmc_command *cmd,
232 			   int stop) { }
233 
dbg_dumpregs(struct s3cmci_host * host,char * prefix)234 static void dbg_dumpregs(struct s3cmci_host *host, char *prefix) { }
235 
236 #endif /* CONFIG_MMC_DEBUG */
237 
238 /**
239  * s3cmci_host_usedma - return whether the host is using dma or pio
240  * @host: The host state
241  *
242  * Return true if the host is using DMA to transfer data, else false
243  * to use PIO mode. Will return static data depending on the driver
244  * configuration.
245  */
s3cmci_host_usedma(struct s3cmci_host * host)246 static inline bool s3cmci_host_usedma(struct s3cmci_host *host)
247 {
248 #ifdef CONFIG_MMC_S3C_PIO
249 	return false;
250 #else /* CONFIG_MMC_S3C_DMA */
251 	return true;
252 #endif
253 }
254 
enable_imask(struct s3cmci_host * host,u32 imask)255 static inline u32 enable_imask(struct s3cmci_host *host, u32 imask)
256 {
257 	u32 newmask;
258 
259 	newmask = readl(host->base + host->sdiimsk);
260 	newmask |= imask;
261 
262 	writel(newmask, host->base + host->sdiimsk);
263 
264 	return newmask;
265 }
266 
disable_imask(struct s3cmci_host * host,u32 imask)267 static inline u32 disable_imask(struct s3cmci_host *host, u32 imask)
268 {
269 	u32 newmask;
270 
271 	newmask = readl(host->base + host->sdiimsk);
272 	newmask &= ~imask;
273 
274 	writel(newmask, host->base + host->sdiimsk);
275 
276 	return newmask;
277 }
278 
clear_imask(struct s3cmci_host * host)279 static inline void clear_imask(struct s3cmci_host *host)
280 {
281 	u32 mask = readl(host->base + host->sdiimsk);
282 
283 	/* preserve the SDIO IRQ mask state */
284 	mask &= S3C2410_SDIIMSK_SDIOIRQ;
285 	writel(mask, host->base + host->sdiimsk);
286 }
287 
288 /**
289  * s3cmci_check_sdio_irq - test whether the SDIO IRQ is being signalled
290  * @host: The host to check.
291  *
292  * Test to see if the SDIO interrupt is being signalled in case the
293  * controller has failed to re-detect a card interrupt. Read GPE8 and
294  * see if it is low and if so, signal a SDIO interrupt.
295  *
296  * This is currently called if a request is finished (we assume that the
297  * bus is now idle) and when the SDIO IRQ is enabled in case the IRQ is
298  * already being indicated.
299 */
s3cmci_check_sdio_irq(struct s3cmci_host * host)300 static void s3cmci_check_sdio_irq(struct s3cmci_host *host)
301 {
302 	if (host->sdio_irqen) {
303 		if (host->pdata->bus[3] &&
304 		    gpiod_get_value(host->pdata->bus[3]) == 0) {
305 			pr_debug("%s: signalling irq\n", __func__);
306 			mmc_signal_sdio_irq(host->mmc);
307 		}
308 	}
309 }
310 
get_data_buffer(struct s3cmci_host * host,u32 * bytes,u32 ** pointer)311 static inline int get_data_buffer(struct s3cmci_host *host,
312 				  u32 *bytes, u32 **pointer)
313 {
314 	struct scatterlist *sg;
315 
316 	if (host->pio_active == XFER_NONE)
317 		return -EINVAL;
318 
319 	if ((!host->mrq) || (!host->mrq->data))
320 		return -EINVAL;
321 
322 	if (host->pio_sgptr >= host->mrq->data->sg_len) {
323 		dbg(host, dbg_debug, "no more buffers (%i/%i)\n",
324 		      host->pio_sgptr, host->mrq->data->sg_len);
325 		return -EBUSY;
326 	}
327 	sg = &host->mrq->data->sg[host->pio_sgptr];
328 
329 	*bytes = sg->length;
330 	*pointer = sg_virt(sg);
331 
332 	host->pio_sgptr++;
333 
334 	dbg(host, dbg_sg, "new buffer (%i/%i)\n",
335 	    host->pio_sgptr, host->mrq->data->sg_len);
336 
337 	return 0;
338 }
339 
fifo_count(struct s3cmci_host * host)340 static inline u32 fifo_count(struct s3cmci_host *host)
341 {
342 	u32 fifostat = readl(host->base + S3C2410_SDIFSTA);
343 
344 	fifostat &= S3C2410_SDIFSTA_COUNTMASK;
345 	return fifostat;
346 }
347 
fifo_free(struct s3cmci_host * host)348 static inline u32 fifo_free(struct s3cmci_host *host)
349 {
350 	u32 fifostat = readl(host->base + S3C2410_SDIFSTA);
351 
352 	fifostat &= S3C2410_SDIFSTA_COUNTMASK;
353 	return 63 - fifostat;
354 }
355 
356 /**
357  * s3cmci_enable_irq - enable IRQ, after having disabled it.
358  * @host: The device state.
359  * @more: True if more IRQs are expected from transfer.
360  *
361  * Enable the main IRQ if needed after it has been disabled.
362  *
363  * The IRQ can be one of the following states:
364  *	- disabled during IDLE
365  *	- disabled whilst processing data
366  *	- enabled during transfer
367  *	- enabled whilst awaiting SDIO interrupt detection
368  */
s3cmci_enable_irq(struct s3cmci_host * host,bool more)369 static void s3cmci_enable_irq(struct s3cmci_host *host, bool more)
370 {
371 	unsigned long flags;
372 	bool enable = false;
373 
374 	local_irq_save(flags);
375 
376 	host->irq_enabled = more;
377 	host->irq_disabled = false;
378 
379 	enable = more | host->sdio_irqen;
380 
381 	if (host->irq_state != enable) {
382 		host->irq_state = enable;
383 
384 		if (enable)
385 			enable_irq(host->irq);
386 		else
387 			disable_irq(host->irq);
388 	}
389 
390 	local_irq_restore(flags);
391 }
392 
s3cmci_disable_irq(struct s3cmci_host * host,bool transfer)393 static void s3cmci_disable_irq(struct s3cmci_host *host, bool transfer)
394 {
395 	unsigned long flags;
396 
397 	local_irq_save(flags);
398 
399 	/* pr_debug("%s: transfer %d\n", __func__, transfer); */
400 
401 	host->irq_disabled = transfer;
402 
403 	if (transfer && host->irq_state) {
404 		host->irq_state = false;
405 		disable_irq(host->irq);
406 	}
407 
408 	local_irq_restore(flags);
409 }
410 
do_pio_read(struct s3cmci_host * host)411 static void do_pio_read(struct s3cmci_host *host)
412 {
413 	int res;
414 	u32 fifo;
415 	u32 *ptr;
416 	u32 fifo_words;
417 	void __iomem *from_ptr;
418 
419 	/* write real prescaler to host, it might be set slow to fix */
420 	writel(host->prescaler, host->base + S3C2410_SDIPRE);
421 
422 	from_ptr = host->base + host->sdidata;
423 
424 	while ((fifo = fifo_count(host))) {
425 		if (!host->pio_bytes) {
426 			res = get_data_buffer(host, &host->pio_bytes,
427 					      &host->pio_ptr);
428 			if (res) {
429 				host->pio_active = XFER_NONE;
430 				host->complete_what = COMPLETION_FINALIZE;
431 
432 				dbg(host, dbg_pio, "pio_read(): "
433 				    "complete (no more data).\n");
434 				return;
435 			}
436 
437 			dbg(host, dbg_pio,
438 			    "pio_read(): new target: [%i]@[%p]\n",
439 			    host->pio_bytes, host->pio_ptr);
440 		}
441 
442 		dbg(host, dbg_pio,
443 		    "pio_read(): fifo:[%02i] buffer:[%03i] dcnt:[%08X]\n",
444 		    fifo, host->pio_bytes,
445 		    readl(host->base + S3C2410_SDIDCNT));
446 
447 		/* If we have reached the end of the block, we can
448 		 * read a word and get 1 to 3 bytes.  If we in the
449 		 * middle of the block, we have to read full words,
450 		 * otherwise we will write garbage, so round down to
451 		 * an even multiple of 4. */
452 		if (fifo >= host->pio_bytes)
453 			fifo = host->pio_bytes;
454 		else
455 			fifo -= fifo & 3;
456 
457 		host->pio_bytes -= fifo;
458 		host->pio_count += fifo;
459 
460 		fifo_words = fifo >> 2;
461 		ptr = host->pio_ptr;
462 		while (fifo_words--)
463 			*ptr++ = readl(from_ptr);
464 		host->pio_ptr = ptr;
465 
466 		if (fifo & 3) {
467 			u32 n = fifo & 3;
468 			u32 data = readl(from_ptr);
469 			u8 *p = (u8 *)host->pio_ptr;
470 
471 			while (n--) {
472 				*p++ = data;
473 				data >>= 8;
474 			}
475 		}
476 	}
477 
478 	if (!host->pio_bytes) {
479 		res = get_data_buffer(host, &host->pio_bytes, &host->pio_ptr);
480 		if (res) {
481 			dbg(host, dbg_pio,
482 			    "pio_read(): complete (no more buffers).\n");
483 			host->pio_active = XFER_NONE;
484 			host->complete_what = COMPLETION_FINALIZE;
485 
486 			return;
487 		}
488 	}
489 
490 	enable_imask(host,
491 		     S3C2410_SDIIMSK_RXFIFOHALF | S3C2410_SDIIMSK_RXFIFOLAST);
492 }
493 
do_pio_write(struct s3cmci_host * host)494 static void do_pio_write(struct s3cmci_host *host)
495 {
496 	void __iomem *to_ptr;
497 	int res;
498 	u32 fifo;
499 	u32 *ptr;
500 
501 	to_ptr = host->base + host->sdidata;
502 
503 	while ((fifo = fifo_free(host)) > 3) {
504 		if (!host->pio_bytes) {
505 			res = get_data_buffer(host, &host->pio_bytes,
506 							&host->pio_ptr);
507 			if (res) {
508 				dbg(host, dbg_pio,
509 				    "pio_write(): complete (no more data).\n");
510 				host->pio_active = XFER_NONE;
511 
512 				return;
513 			}
514 
515 			dbg(host, dbg_pio,
516 			    "pio_write(): new source: [%i]@[%p]\n",
517 			    host->pio_bytes, host->pio_ptr);
518 
519 		}
520 
521 		/* If we have reached the end of the block, we have to
522 		 * write exactly the remaining number of bytes.  If we
523 		 * in the middle of the block, we have to write full
524 		 * words, so round down to an even multiple of 4. */
525 		if (fifo >= host->pio_bytes)
526 			fifo = host->pio_bytes;
527 		else
528 			fifo -= fifo & 3;
529 
530 		host->pio_bytes -= fifo;
531 		host->pio_count += fifo;
532 
533 		fifo = (fifo + 3) >> 2;
534 		ptr = host->pio_ptr;
535 		while (fifo--)
536 			writel(*ptr++, to_ptr);
537 		host->pio_ptr = ptr;
538 	}
539 
540 	enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
541 }
542 
pio_tasklet(struct tasklet_struct * t)543 static void pio_tasklet(struct tasklet_struct *t)
544 {
545 	struct s3cmci_host *host = from_tasklet(host, t, pio_tasklet);
546 
547 	s3cmci_disable_irq(host, true);
548 
549 	if (host->pio_active == XFER_WRITE)
550 		do_pio_write(host);
551 
552 	if (host->pio_active == XFER_READ)
553 		do_pio_read(host);
554 
555 	if (host->complete_what == COMPLETION_FINALIZE) {
556 		clear_imask(host);
557 		if (host->pio_active != XFER_NONE) {
558 			dbg(host, dbg_err, "unfinished %s "
559 			    "- pio_count:[%u] pio_bytes:[%u]\n",
560 			    (host->pio_active == XFER_READ) ? "read" : "write",
561 			    host->pio_count, host->pio_bytes);
562 
563 			if (host->mrq->data)
564 				host->mrq->data->error = -EINVAL;
565 		}
566 
567 		s3cmci_enable_irq(host, false);
568 		finalize_request(host);
569 	} else
570 		s3cmci_enable_irq(host, true);
571 }
572 
573 /*
574  * ISR for SDI Interface IRQ
575  * Communication between driver and ISR works as follows:
576  *   host->mrq 			points to current request
577  *   host->complete_what	Indicates when the request is considered done
578  *     COMPLETION_CMDSENT	  when the command was sent
579  *     COMPLETION_RSPFIN          when a response was received
580  *     COMPLETION_XFERFINISH	  when the data transfer is finished
581  *     COMPLETION_XFERFINISH_RSPFIN both of the above.
582  *   host->complete_request	is the completion-object the driver waits for
583  *
584  * 1) Driver sets up host->mrq and host->complete_what
585  * 2) Driver prepares the transfer
586  * 3) Driver enables interrupts
587  * 4) Driver starts transfer
588  * 5) Driver waits for host->complete_rquest
589  * 6) ISR checks for request status (errors and success)
590  * 6) ISR sets host->mrq->cmd->error and host->mrq->data->error
591  * 7) ISR completes host->complete_request
592  * 8) ISR disables interrupts
593  * 9) Driver wakes up and takes care of the request
594  *
595  * Note: "->error"-fields are expected to be set to 0 before the request
596  *       was issued by mmc.c - therefore they are only set, when an error
597  *       contition comes up
598  */
599 
s3cmci_irq(int irq,void * dev_id)600 static irqreturn_t s3cmci_irq(int irq, void *dev_id)
601 {
602 	struct s3cmci_host *host = dev_id;
603 	struct mmc_command *cmd;
604 	u32 mci_csta, mci_dsta, mci_fsta, mci_dcnt, mci_imsk;
605 	u32 mci_cclear = 0, mci_dclear;
606 	unsigned long iflags;
607 
608 	mci_dsta = readl(host->base + S3C2410_SDIDSTA);
609 	mci_imsk = readl(host->base + host->sdiimsk);
610 
611 	if (mci_dsta & S3C2410_SDIDSTA_SDIOIRQDETECT) {
612 		if (mci_imsk & S3C2410_SDIIMSK_SDIOIRQ) {
613 			mci_dclear = S3C2410_SDIDSTA_SDIOIRQDETECT;
614 			writel(mci_dclear, host->base + S3C2410_SDIDSTA);
615 
616 			mmc_signal_sdio_irq(host->mmc);
617 			return IRQ_HANDLED;
618 		}
619 	}
620 
621 	spin_lock_irqsave(&host->complete_lock, iflags);
622 
623 	mci_csta = readl(host->base + S3C2410_SDICMDSTAT);
624 	mci_dcnt = readl(host->base + S3C2410_SDIDCNT);
625 	mci_fsta = readl(host->base + S3C2410_SDIFSTA);
626 	mci_dclear = 0;
627 
628 	if ((host->complete_what == COMPLETION_NONE) ||
629 	    (host->complete_what == COMPLETION_FINALIZE)) {
630 		host->status = "nothing to complete";
631 		clear_imask(host);
632 		goto irq_out;
633 	}
634 
635 	if (!host->mrq) {
636 		host->status = "no active mrq";
637 		clear_imask(host);
638 		goto irq_out;
639 	}
640 
641 	cmd = host->cmd_is_stop ? host->mrq->stop : host->mrq->cmd;
642 
643 	if (!cmd) {
644 		host->status = "no active cmd";
645 		clear_imask(host);
646 		goto irq_out;
647 	}
648 
649 	if (!s3cmci_host_usedma(host)) {
650 		if ((host->pio_active == XFER_WRITE) &&
651 		    (mci_fsta & S3C2410_SDIFSTA_TFDET)) {
652 
653 			disable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
654 			tasklet_schedule(&host->pio_tasklet);
655 			host->status = "pio tx";
656 		}
657 
658 		if ((host->pio_active == XFER_READ) &&
659 		    (mci_fsta & S3C2410_SDIFSTA_RFDET)) {
660 
661 			disable_imask(host,
662 				      S3C2410_SDIIMSK_RXFIFOHALF |
663 				      S3C2410_SDIIMSK_RXFIFOLAST);
664 
665 			tasklet_schedule(&host->pio_tasklet);
666 			host->status = "pio rx";
667 		}
668 	}
669 
670 	if (mci_csta & S3C2410_SDICMDSTAT_CMDTIMEOUT) {
671 		dbg(host, dbg_err, "CMDSTAT: error CMDTIMEOUT\n");
672 		cmd->error = -ETIMEDOUT;
673 		host->status = "error: command timeout";
674 		goto fail_transfer;
675 	}
676 
677 	if (mci_csta & S3C2410_SDICMDSTAT_CMDSENT) {
678 		if (host->complete_what == COMPLETION_CMDSENT) {
679 			host->status = "ok: command sent";
680 			goto close_transfer;
681 		}
682 
683 		mci_cclear |= S3C2410_SDICMDSTAT_CMDSENT;
684 	}
685 
686 	if (mci_csta & S3C2410_SDICMDSTAT_CRCFAIL) {
687 		if (cmd->flags & MMC_RSP_CRC) {
688 			if (host->mrq->cmd->flags & MMC_RSP_136) {
689 				dbg(host, dbg_irq,
690 				    "fixup: ignore CRC fail with long rsp\n");
691 			} else {
692 				/* note, we used to fail the transfer
693 				 * here, but it seems that this is just
694 				 * the hardware getting it wrong.
695 				 *
696 				 * cmd->error = -EILSEQ;
697 				 * host->status = "error: bad command crc";
698 				 * goto fail_transfer;
699 				*/
700 			}
701 		}
702 
703 		mci_cclear |= S3C2410_SDICMDSTAT_CRCFAIL;
704 	}
705 
706 	if (mci_csta & S3C2410_SDICMDSTAT_RSPFIN) {
707 		if (host->complete_what == COMPLETION_RSPFIN) {
708 			host->status = "ok: command response received";
709 			goto close_transfer;
710 		}
711 
712 		if (host->complete_what == COMPLETION_XFERFINISH_RSPFIN)
713 			host->complete_what = COMPLETION_XFERFINISH;
714 
715 		mci_cclear |= S3C2410_SDICMDSTAT_RSPFIN;
716 	}
717 
718 	/* errors handled after this point are only relevant
719 	   when a data transfer is in progress */
720 
721 	if (!cmd->data)
722 		goto clear_status_bits;
723 
724 	/* Check for FIFO failure */
725 	if (host->is2440) {
726 		if (mci_fsta & S3C2440_SDIFSTA_FIFOFAIL) {
727 			dbg(host, dbg_err, "FIFO failure\n");
728 			host->mrq->data->error = -EILSEQ;
729 			host->status = "error: 2440 fifo failure";
730 			goto fail_transfer;
731 		}
732 	} else {
733 		if (mci_dsta & S3C2410_SDIDSTA_FIFOFAIL) {
734 			dbg(host, dbg_err, "FIFO failure\n");
735 			cmd->data->error = -EILSEQ;
736 			host->status = "error:  fifo failure";
737 			goto fail_transfer;
738 		}
739 	}
740 
741 	if (mci_dsta & S3C2410_SDIDSTA_RXCRCFAIL) {
742 		dbg(host, dbg_err, "bad data crc (outgoing)\n");
743 		cmd->data->error = -EILSEQ;
744 		host->status = "error: bad data crc (outgoing)";
745 		goto fail_transfer;
746 	}
747 
748 	if (mci_dsta & S3C2410_SDIDSTA_CRCFAIL) {
749 		dbg(host, dbg_err, "bad data crc (incoming)\n");
750 		cmd->data->error = -EILSEQ;
751 		host->status = "error: bad data crc (incoming)";
752 		goto fail_transfer;
753 	}
754 
755 	if (mci_dsta & S3C2410_SDIDSTA_DATATIMEOUT) {
756 		dbg(host, dbg_err, "data timeout\n");
757 		cmd->data->error = -ETIMEDOUT;
758 		host->status = "error: data timeout";
759 		goto fail_transfer;
760 	}
761 
762 	if (mci_dsta & S3C2410_SDIDSTA_XFERFINISH) {
763 		if (host->complete_what == COMPLETION_XFERFINISH) {
764 			host->status = "ok: data transfer completed";
765 			goto close_transfer;
766 		}
767 
768 		if (host->complete_what == COMPLETION_XFERFINISH_RSPFIN)
769 			host->complete_what = COMPLETION_RSPFIN;
770 
771 		mci_dclear |= S3C2410_SDIDSTA_XFERFINISH;
772 	}
773 
774 clear_status_bits:
775 	writel(mci_cclear, host->base + S3C2410_SDICMDSTAT);
776 	writel(mci_dclear, host->base + S3C2410_SDIDSTA);
777 
778 	goto irq_out;
779 
780 fail_transfer:
781 	host->pio_active = XFER_NONE;
782 
783 close_transfer:
784 	host->complete_what = COMPLETION_FINALIZE;
785 
786 	clear_imask(host);
787 	tasklet_schedule(&host->pio_tasklet);
788 
789 	goto irq_out;
790 
791 irq_out:
792 	dbg(host, dbg_irq,
793 	    "csta:0x%08x dsta:0x%08x fsta:0x%08x dcnt:0x%08x status:%s.\n",
794 	    mci_csta, mci_dsta, mci_fsta, mci_dcnt, host->status);
795 
796 	spin_unlock_irqrestore(&host->complete_lock, iflags);
797 	return IRQ_HANDLED;
798 
799 }
800 
s3cmci_dma_done_callback(void * arg)801 static void s3cmci_dma_done_callback(void *arg)
802 {
803 	struct s3cmci_host *host = arg;
804 	unsigned long iflags;
805 
806 	BUG_ON(!host->mrq);
807 	BUG_ON(!host->mrq->data);
808 
809 	spin_lock_irqsave(&host->complete_lock, iflags);
810 
811 	dbg(host, dbg_dma, "DMA FINISHED\n");
812 
813 	host->dma_complete = 1;
814 	host->complete_what = COMPLETION_FINALIZE;
815 
816 	tasklet_schedule(&host->pio_tasklet);
817 	spin_unlock_irqrestore(&host->complete_lock, iflags);
818 
819 }
820 
finalize_request(struct s3cmci_host * host)821 static void finalize_request(struct s3cmci_host *host)
822 {
823 	struct mmc_request *mrq = host->mrq;
824 	struct mmc_command *cmd;
825 	int debug_as_failure = 0;
826 
827 	if (host->complete_what != COMPLETION_FINALIZE)
828 		return;
829 
830 	if (!mrq)
831 		return;
832 	cmd = host->cmd_is_stop ? mrq->stop : mrq->cmd;
833 
834 	if (cmd->data && (cmd->error == 0) &&
835 	    (cmd->data->error == 0)) {
836 		if (s3cmci_host_usedma(host) && (!host->dma_complete)) {
837 			dbg(host, dbg_dma, "DMA Missing (%d)!\n",
838 			    host->dma_complete);
839 			return;
840 		}
841 	}
842 
843 	/* Read response from controller. */
844 	cmd->resp[0] = readl(host->base + S3C2410_SDIRSP0);
845 	cmd->resp[1] = readl(host->base + S3C2410_SDIRSP1);
846 	cmd->resp[2] = readl(host->base + S3C2410_SDIRSP2);
847 	cmd->resp[3] = readl(host->base + S3C2410_SDIRSP3);
848 
849 	writel(host->prescaler, host->base + S3C2410_SDIPRE);
850 
851 	if (cmd->error)
852 		debug_as_failure = 1;
853 
854 	if (cmd->data && cmd->data->error)
855 		debug_as_failure = 1;
856 
857 	dbg_dumpcmd(host, cmd, debug_as_failure);
858 
859 	/* Cleanup controller */
860 	writel(0, host->base + S3C2410_SDICMDARG);
861 	writel(S3C2410_SDIDCON_STOP, host->base + S3C2410_SDIDCON);
862 	writel(0, host->base + S3C2410_SDICMDCON);
863 	clear_imask(host);
864 
865 	if (cmd->data && cmd->error)
866 		cmd->data->error = cmd->error;
867 
868 	if (cmd->data && cmd->data->stop && (!host->cmd_is_stop)) {
869 		host->cmd_is_stop = 1;
870 		s3cmci_send_request(host->mmc);
871 		return;
872 	}
873 
874 	/* If we have no data transfer we are finished here */
875 	if (!mrq->data)
876 		goto request_done;
877 
878 	/* Calculate the amout of bytes transfer if there was no error */
879 	if (mrq->data->error == 0) {
880 		mrq->data->bytes_xfered =
881 			(mrq->data->blocks * mrq->data->blksz);
882 	} else {
883 		mrq->data->bytes_xfered = 0;
884 	}
885 
886 	/* If we had an error while transferring data we flush the
887 	 * DMA channel and the fifo to clear out any garbage. */
888 	if (mrq->data->error != 0) {
889 		if (s3cmci_host_usedma(host))
890 			dmaengine_terminate_all(host->dma);
891 
892 		if (host->is2440) {
893 			/* Clear failure register and reset fifo. */
894 			writel(S3C2440_SDIFSTA_FIFORESET |
895 			       S3C2440_SDIFSTA_FIFOFAIL,
896 			       host->base + S3C2410_SDIFSTA);
897 		} else {
898 			u32 mci_con;
899 
900 			/* reset fifo */
901 			mci_con = readl(host->base + S3C2410_SDICON);
902 			mci_con |= S3C2410_SDICON_FIFORESET;
903 
904 			writel(mci_con, host->base + S3C2410_SDICON);
905 		}
906 	}
907 
908 request_done:
909 	host->complete_what = COMPLETION_NONE;
910 	host->mrq = NULL;
911 
912 	s3cmci_check_sdio_irq(host);
913 	mmc_request_done(host->mmc, mrq);
914 }
915 
s3cmci_send_command(struct s3cmci_host * host,struct mmc_command * cmd)916 static void s3cmci_send_command(struct s3cmci_host *host,
917 					struct mmc_command *cmd)
918 {
919 	u32 ccon, imsk;
920 
921 	imsk  = S3C2410_SDIIMSK_CRCSTATUS | S3C2410_SDIIMSK_CMDTIMEOUT |
922 		S3C2410_SDIIMSK_RESPONSEND | S3C2410_SDIIMSK_CMDSENT |
923 		S3C2410_SDIIMSK_RESPONSECRC;
924 
925 	enable_imask(host, imsk);
926 
927 	if (cmd->data)
928 		host->complete_what = COMPLETION_XFERFINISH_RSPFIN;
929 	else if (cmd->flags & MMC_RSP_PRESENT)
930 		host->complete_what = COMPLETION_RSPFIN;
931 	else
932 		host->complete_what = COMPLETION_CMDSENT;
933 
934 	writel(cmd->arg, host->base + S3C2410_SDICMDARG);
935 
936 	ccon  = cmd->opcode & S3C2410_SDICMDCON_INDEX;
937 	ccon |= S3C2410_SDICMDCON_SENDERHOST | S3C2410_SDICMDCON_CMDSTART;
938 
939 	if (cmd->flags & MMC_RSP_PRESENT)
940 		ccon |= S3C2410_SDICMDCON_WAITRSP;
941 
942 	if (cmd->flags & MMC_RSP_136)
943 		ccon |= S3C2410_SDICMDCON_LONGRSP;
944 
945 	writel(ccon, host->base + S3C2410_SDICMDCON);
946 }
947 
s3cmci_setup_data(struct s3cmci_host * host,struct mmc_data * data)948 static int s3cmci_setup_data(struct s3cmci_host *host, struct mmc_data *data)
949 {
950 	u32 dcon, imsk, stoptries = 3;
951 
952 	if ((data->blksz & 3) != 0) {
953 		/* We cannot deal with unaligned blocks with more than
954 		 * one block being transferred. */
955 
956 		if (data->blocks > 1) {
957 			pr_warn("%s: can't do non-word sized block transfers (blksz %d)\n",
958 				__func__, data->blksz);
959 			return -EINVAL;
960 		}
961 	}
962 
963 	while (readl(host->base + S3C2410_SDIDSTA) &
964 	       (S3C2410_SDIDSTA_TXDATAON | S3C2410_SDIDSTA_RXDATAON)) {
965 
966 		dbg(host, dbg_err,
967 		    "mci_setup_data() transfer stillin progress.\n");
968 
969 		writel(S3C2410_SDIDCON_STOP, host->base + S3C2410_SDIDCON);
970 		s3cmci_reset(host);
971 
972 		if ((stoptries--) == 0) {
973 			dbg_dumpregs(host, "DRF");
974 			return -EINVAL;
975 		}
976 	}
977 
978 	dcon  = data->blocks & S3C2410_SDIDCON_BLKNUM_MASK;
979 
980 	if (s3cmci_host_usedma(host))
981 		dcon |= S3C2410_SDIDCON_DMAEN;
982 
983 	if (host->bus_width == MMC_BUS_WIDTH_4)
984 		dcon |= S3C2410_SDIDCON_WIDEBUS;
985 
986 	dcon |= S3C2410_SDIDCON_BLOCKMODE;
987 
988 	if (data->flags & MMC_DATA_WRITE) {
989 		dcon |= S3C2410_SDIDCON_TXAFTERRESP;
990 		dcon |= S3C2410_SDIDCON_XFER_TXSTART;
991 	}
992 
993 	if (data->flags & MMC_DATA_READ) {
994 		dcon |= S3C2410_SDIDCON_RXAFTERCMD;
995 		dcon |= S3C2410_SDIDCON_XFER_RXSTART;
996 	}
997 
998 	if (host->is2440) {
999 		dcon |= S3C2440_SDIDCON_DS_WORD;
1000 		dcon |= S3C2440_SDIDCON_DATSTART;
1001 	}
1002 
1003 	writel(dcon, host->base + S3C2410_SDIDCON);
1004 
1005 	/* write BSIZE register */
1006 
1007 	writel(data->blksz, host->base + S3C2410_SDIBSIZE);
1008 
1009 	/* add to IMASK register */
1010 	imsk = S3C2410_SDIIMSK_FIFOFAIL | S3C2410_SDIIMSK_DATACRC |
1011 	       S3C2410_SDIIMSK_DATATIMEOUT | S3C2410_SDIIMSK_DATAFINISH;
1012 
1013 	enable_imask(host, imsk);
1014 
1015 	/* write TIMER register */
1016 
1017 	if (host->is2440) {
1018 		writel(0x007FFFFF, host->base + S3C2410_SDITIMER);
1019 	} else {
1020 		writel(0x0000FFFF, host->base + S3C2410_SDITIMER);
1021 
1022 		/* FIX: set slow clock to prevent timeouts on read */
1023 		if (data->flags & MMC_DATA_READ)
1024 			writel(0xFF, host->base + S3C2410_SDIPRE);
1025 	}
1026 
1027 	return 0;
1028 }
1029 
1030 #define BOTH_DIR (MMC_DATA_WRITE | MMC_DATA_READ)
1031 
s3cmci_prepare_pio(struct s3cmci_host * host,struct mmc_data * data)1032 static int s3cmci_prepare_pio(struct s3cmci_host *host, struct mmc_data *data)
1033 {
1034 	int rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
1035 
1036 	BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);
1037 
1038 	host->pio_sgptr = 0;
1039 	host->pio_bytes = 0;
1040 	host->pio_count = 0;
1041 	host->pio_active = rw ? XFER_WRITE : XFER_READ;
1042 
1043 	if (rw) {
1044 		do_pio_write(host);
1045 		enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
1046 	} else {
1047 		enable_imask(host, S3C2410_SDIIMSK_RXFIFOHALF
1048 			     | S3C2410_SDIIMSK_RXFIFOLAST);
1049 	}
1050 
1051 	return 0;
1052 }
1053 
s3cmci_prepare_dma(struct s3cmci_host * host,struct mmc_data * data)1054 static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data)
1055 {
1056 	int rw = data->flags & MMC_DATA_WRITE;
1057 	struct dma_async_tx_descriptor *desc;
1058 	struct dma_slave_config conf = {
1059 		.src_addr = host->mem->start + host->sdidata,
1060 		.dst_addr = host->mem->start + host->sdidata,
1061 		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
1062 		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
1063 	};
1064 
1065 	BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);
1066 
1067 	/* Restore prescaler value */
1068 	writel(host->prescaler, host->base + S3C2410_SDIPRE);
1069 
1070 	if (!rw)
1071 		conf.direction = DMA_DEV_TO_MEM;
1072 	else
1073 		conf.direction = DMA_MEM_TO_DEV;
1074 
1075 	dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
1076 		   mmc_get_dma_dir(data));
1077 
1078 	dmaengine_slave_config(host->dma, &conf);
1079 	desc = dmaengine_prep_slave_sg(host->dma, data->sg, data->sg_len,
1080 		conf.direction,
1081 		DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
1082 	if (!desc)
1083 		goto unmap_exit;
1084 	desc->callback = s3cmci_dma_done_callback;
1085 	desc->callback_param = host;
1086 	dmaengine_submit(desc);
1087 	dma_async_issue_pending(host->dma);
1088 
1089 	return 0;
1090 
1091 unmap_exit:
1092 	dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
1093 		     mmc_get_dma_dir(data));
1094 	return -ENOMEM;
1095 }
1096 
s3cmci_send_request(struct mmc_host * mmc)1097 static void s3cmci_send_request(struct mmc_host *mmc)
1098 {
1099 	struct s3cmci_host *host = mmc_priv(mmc);
1100 	struct mmc_request *mrq = host->mrq;
1101 	struct mmc_command *cmd = host->cmd_is_stop ? mrq->stop : mrq->cmd;
1102 
1103 	host->ccnt++;
1104 	prepare_dbgmsg(host, cmd, host->cmd_is_stop);
1105 
1106 	/* Clear command, data and fifo status registers
1107 	   Fifo clear only necessary on 2440, but doesn't hurt on 2410
1108 	*/
1109 	writel(0xFFFFFFFF, host->base + S3C2410_SDICMDSTAT);
1110 	writel(0xFFFFFFFF, host->base + S3C2410_SDIDSTA);
1111 	writel(0xFFFFFFFF, host->base + S3C2410_SDIFSTA);
1112 
1113 	if (cmd->data) {
1114 		int res = s3cmci_setup_data(host, cmd->data);
1115 
1116 		host->dcnt++;
1117 
1118 		if (res) {
1119 			dbg(host, dbg_err, "setup data error %d\n", res);
1120 			cmd->error = res;
1121 			cmd->data->error = res;
1122 
1123 			mmc_request_done(mmc, mrq);
1124 			return;
1125 		}
1126 
1127 		if (s3cmci_host_usedma(host))
1128 			res = s3cmci_prepare_dma(host, cmd->data);
1129 		else
1130 			res = s3cmci_prepare_pio(host, cmd->data);
1131 
1132 		if (res) {
1133 			dbg(host, dbg_err, "data prepare error %d\n", res);
1134 			cmd->error = res;
1135 			cmd->data->error = res;
1136 
1137 			mmc_request_done(mmc, mrq);
1138 			return;
1139 		}
1140 	}
1141 
1142 	/* Send command */
1143 	s3cmci_send_command(host, cmd);
1144 
1145 	/* Enable Interrupt */
1146 	s3cmci_enable_irq(host, true);
1147 }
1148 
s3cmci_request(struct mmc_host * mmc,struct mmc_request * mrq)1149 static void s3cmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
1150 {
1151 	struct s3cmci_host *host = mmc_priv(mmc);
1152 
1153 	host->status = "mmc request";
1154 	host->cmd_is_stop = 0;
1155 	host->mrq = mrq;
1156 
1157 	if (mmc_gpio_get_cd(mmc) == 0) {
1158 		dbg(host, dbg_err, "%s: no medium present\n", __func__);
1159 		host->mrq->cmd->error = -ENOMEDIUM;
1160 		mmc_request_done(mmc, mrq);
1161 	} else
1162 		s3cmci_send_request(mmc);
1163 }
1164 
s3cmci_set_clk(struct s3cmci_host * host,struct mmc_ios * ios)1165 static void s3cmci_set_clk(struct s3cmci_host *host, struct mmc_ios *ios)
1166 {
1167 	u32 mci_psc;
1168 
1169 	/* Set clock */
1170 	for (mci_psc = 0; mci_psc < 255; mci_psc++) {
1171 		host->real_rate = host->clk_rate / (host->clk_div*(mci_psc+1));
1172 
1173 		if (host->real_rate <= ios->clock)
1174 			break;
1175 	}
1176 
1177 	if (mci_psc > 255)
1178 		mci_psc = 255;
1179 
1180 	host->prescaler = mci_psc;
1181 	writel(host->prescaler, host->base + S3C2410_SDIPRE);
1182 
1183 	/* If requested clock is 0, real_rate will be 0, too */
1184 	if (ios->clock == 0)
1185 		host->real_rate = 0;
1186 }
1187 
s3cmci_set_ios(struct mmc_host * mmc,struct mmc_ios * ios)1188 static void s3cmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1189 {
1190 	struct s3cmci_host *host = mmc_priv(mmc);
1191 	u32 mci_con;
1192 
1193 	/* Set the power state */
1194 
1195 	mci_con = readl(host->base + S3C2410_SDICON);
1196 
1197 	switch (ios->power_mode) {
1198 	case MMC_POWER_ON:
1199 	case MMC_POWER_UP:
1200 		if (!host->is2440)
1201 			mci_con |= S3C2410_SDICON_FIFORESET;
1202 		break;
1203 
1204 	case MMC_POWER_OFF:
1205 	default:
1206 		if (host->is2440)
1207 			mci_con |= S3C2440_SDICON_SDRESET;
1208 		break;
1209 	}
1210 
1211 	if (host->pdata->set_power)
1212 		host->pdata->set_power(ios->power_mode, ios->vdd);
1213 
1214 	s3cmci_set_clk(host, ios);
1215 
1216 	/* Set CLOCK_ENABLE */
1217 	if (ios->clock)
1218 		mci_con |= S3C2410_SDICON_CLOCKTYPE;
1219 	else
1220 		mci_con &= ~S3C2410_SDICON_CLOCKTYPE;
1221 
1222 	writel(mci_con, host->base + S3C2410_SDICON);
1223 
1224 	if ((ios->power_mode == MMC_POWER_ON) ||
1225 	    (ios->power_mode == MMC_POWER_UP)) {
1226 		dbg(host, dbg_conf, "running at %lukHz (requested: %ukHz).\n",
1227 			host->real_rate/1000, ios->clock/1000);
1228 	} else {
1229 		dbg(host, dbg_conf, "powered down.\n");
1230 	}
1231 
1232 	host->bus_width = ios->bus_width;
1233 }
1234 
s3cmci_reset(struct s3cmci_host * host)1235 static void s3cmci_reset(struct s3cmci_host *host)
1236 {
1237 	u32 con = readl(host->base + S3C2410_SDICON);
1238 
1239 	con |= S3C2440_SDICON_SDRESET;
1240 	writel(con, host->base + S3C2410_SDICON);
1241 }
1242 
s3cmci_enable_sdio_irq(struct mmc_host * mmc,int enable)1243 static void s3cmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
1244 {
1245 	struct s3cmci_host *host = mmc_priv(mmc);
1246 	unsigned long flags;
1247 	u32 con;
1248 
1249 	local_irq_save(flags);
1250 
1251 	con = readl(host->base + S3C2410_SDICON);
1252 	host->sdio_irqen = enable;
1253 
1254 	if (enable == host->sdio_irqen)
1255 		goto same_state;
1256 
1257 	if (enable) {
1258 		con |= S3C2410_SDICON_SDIOIRQ;
1259 		enable_imask(host, S3C2410_SDIIMSK_SDIOIRQ);
1260 
1261 		if (!host->irq_state && !host->irq_disabled) {
1262 			host->irq_state = true;
1263 			enable_irq(host->irq);
1264 		}
1265 	} else {
1266 		disable_imask(host, S3C2410_SDIIMSK_SDIOIRQ);
1267 		con &= ~S3C2410_SDICON_SDIOIRQ;
1268 
1269 		if (!host->irq_enabled && host->irq_state) {
1270 			disable_irq_nosync(host->irq);
1271 			host->irq_state = false;
1272 		}
1273 	}
1274 
1275 	writel(con, host->base + S3C2410_SDICON);
1276 
1277  same_state:
1278 	local_irq_restore(flags);
1279 
1280 	s3cmci_check_sdio_irq(host);
1281 }
1282 
1283 static const struct mmc_host_ops s3cmci_ops = {
1284 	.request	= s3cmci_request,
1285 	.set_ios	= s3cmci_set_ios,
1286 	.get_ro		= mmc_gpio_get_ro,
1287 	.get_cd		= mmc_gpio_get_cd,
1288 	.enable_sdio_irq = s3cmci_enable_sdio_irq,
1289 };
1290 
1291 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
1292 
s3cmci_cpufreq_transition(struct notifier_block * nb,unsigned long val,void * data)1293 static int s3cmci_cpufreq_transition(struct notifier_block *nb,
1294 				     unsigned long val, void *data)
1295 {
1296 	struct s3cmci_host *host;
1297 	struct mmc_host *mmc;
1298 	unsigned long newclk;
1299 	unsigned long flags;
1300 
1301 	host = container_of(nb, struct s3cmci_host, freq_transition);
1302 	newclk = clk_get_rate(host->clk);
1303 	mmc = host->mmc;
1304 
1305 	if ((val == CPUFREQ_PRECHANGE && newclk > host->clk_rate) ||
1306 	    (val == CPUFREQ_POSTCHANGE && newclk < host->clk_rate)) {
1307 		spin_lock_irqsave(&mmc->lock, flags);
1308 
1309 		host->clk_rate = newclk;
1310 
1311 		if (mmc->ios.power_mode != MMC_POWER_OFF &&
1312 		    mmc->ios.clock != 0)
1313 			s3cmci_set_clk(host, &mmc->ios);
1314 
1315 		spin_unlock_irqrestore(&mmc->lock, flags);
1316 	}
1317 
1318 	return 0;
1319 }
1320 
s3cmci_cpufreq_register(struct s3cmci_host * host)1321 static inline int s3cmci_cpufreq_register(struct s3cmci_host *host)
1322 {
1323 	host->freq_transition.notifier_call = s3cmci_cpufreq_transition;
1324 
1325 	return cpufreq_register_notifier(&host->freq_transition,
1326 					 CPUFREQ_TRANSITION_NOTIFIER);
1327 }
1328 
s3cmci_cpufreq_deregister(struct s3cmci_host * host)1329 static inline void s3cmci_cpufreq_deregister(struct s3cmci_host *host)
1330 {
1331 	cpufreq_unregister_notifier(&host->freq_transition,
1332 				    CPUFREQ_TRANSITION_NOTIFIER);
1333 }
1334 
1335 #else
s3cmci_cpufreq_register(struct s3cmci_host * host)1336 static inline int s3cmci_cpufreq_register(struct s3cmci_host *host)
1337 {
1338 	return 0;
1339 }
1340 
s3cmci_cpufreq_deregister(struct s3cmci_host * host)1341 static inline void s3cmci_cpufreq_deregister(struct s3cmci_host *host)
1342 {
1343 }
1344 #endif
1345 
1346 
1347 #ifdef CONFIG_DEBUG_FS
1348 
s3cmci_state_show(struct seq_file * seq,void * v)1349 static int s3cmci_state_show(struct seq_file *seq, void *v)
1350 {
1351 	struct s3cmci_host *host = seq->private;
1352 
1353 	seq_printf(seq, "Register base = 0x%p\n", host->base);
1354 	seq_printf(seq, "Clock rate = %ld\n", host->clk_rate);
1355 	seq_printf(seq, "Prescale = %d\n", host->prescaler);
1356 	seq_printf(seq, "is2440 = %d\n", host->is2440);
1357 	seq_printf(seq, "IRQ = %d\n", host->irq);
1358 	seq_printf(seq, "IRQ enabled = %d\n", host->irq_enabled);
1359 	seq_printf(seq, "IRQ disabled = %d\n", host->irq_disabled);
1360 	seq_printf(seq, "IRQ state = %d\n", host->irq_state);
1361 	seq_printf(seq, "CD IRQ = %d\n", host->irq_cd);
1362 	seq_printf(seq, "Do DMA = %d\n", s3cmci_host_usedma(host));
1363 	seq_printf(seq, "SDIIMSK at %d\n", host->sdiimsk);
1364 	seq_printf(seq, "SDIDATA at %d\n", host->sdidata);
1365 
1366 	return 0;
1367 }
1368 
1369 DEFINE_SHOW_ATTRIBUTE(s3cmci_state);
1370 
1371 #define DBG_REG(_r) { .addr = S3C2410_SDI##_r, .name = #_r }
1372 
1373 struct s3cmci_reg {
1374 	unsigned short	addr;
1375 	unsigned char	*name;
1376 };
1377 
1378 static const struct s3cmci_reg debug_regs[] = {
1379 	DBG_REG(CON),
1380 	DBG_REG(PRE),
1381 	DBG_REG(CMDARG),
1382 	DBG_REG(CMDCON),
1383 	DBG_REG(CMDSTAT),
1384 	DBG_REG(RSP0),
1385 	DBG_REG(RSP1),
1386 	DBG_REG(RSP2),
1387 	DBG_REG(RSP3),
1388 	DBG_REG(TIMER),
1389 	DBG_REG(BSIZE),
1390 	DBG_REG(DCON),
1391 	DBG_REG(DCNT),
1392 	DBG_REG(DSTA),
1393 	DBG_REG(FSTA),
1394 	{}
1395 };
1396 
s3cmci_regs_show(struct seq_file * seq,void * v)1397 static int s3cmci_regs_show(struct seq_file *seq, void *v)
1398 {
1399 	struct s3cmci_host *host = seq->private;
1400 	const struct s3cmci_reg *rptr = debug_regs;
1401 
1402 	for (; rptr->name; rptr++)
1403 		seq_printf(seq, "SDI%s\t=0x%08x\n", rptr->name,
1404 			   readl(host->base + rptr->addr));
1405 
1406 	seq_printf(seq, "SDIIMSK\t=0x%08x\n", readl(host->base + host->sdiimsk));
1407 
1408 	return 0;
1409 }
1410 
1411 DEFINE_SHOW_ATTRIBUTE(s3cmci_regs);
1412 
s3cmci_debugfs_attach(struct s3cmci_host * host)1413 static void s3cmci_debugfs_attach(struct s3cmci_host *host)
1414 {
1415 	struct device *dev = &host->pdev->dev;
1416 	struct dentry *root;
1417 
1418 	root = debugfs_create_dir(dev_name(dev), NULL);
1419 	host->debug_root = root;
1420 
1421 	debugfs_create_file("state", 0444, root, host, &s3cmci_state_fops);
1422 	debugfs_create_file("regs", 0444, root, host, &s3cmci_regs_fops);
1423 }
1424 
s3cmci_debugfs_remove(struct s3cmci_host * host)1425 static void s3cmci_debugfs_remove(struct s3cmci_host *host)
1426 {
1427 	debugfs_remove_recursive(host->debug_root);
1428 }
1429 
1430 #else
s3cmci_debugfs_attach(struct s3cmci_host * host)1431 static inline void s3cmci_debugfs_attach(struct s3cmci_host *host) { }
s3cmci_debugfs_remove(struct s3cmci_host * host)1432 static inline void s3cmci_debugfs_remove(struct s3cmci_host *host) { }
1433 
1434 #endif /* CONFIG_DEBUG_FS */
1435 
s3cmci_probe_pdata(struct s3cmci_host * host)1436 static int s3cmci_probe_pdata(struct s3cmci_host *host)
1437 {
1438 	struct platform_device *pdev = host->pdev;
1439 	struct mmc_host *mmc = host->mmc;
1440 	struct s3c24xx_mci_pdata *pdata;
1441 	int i, ret;
1442 
1443 	host->is2440 = platform_get_device_id(pdev)->driver_data;
1444 	pdata = pdev->dev.platform_data;
1445 	if (!pdata) {
1446 		dev_err(&pdev->dev, "need platform data");
1447 		return -ENXIO;
1448 	}
1449 
1450 	for (i = 0; i < 6; i++) {
1451 		pdata->bus[i] = devm_gpiod_get_index(&pdev->dev, "bus", i,
1452 						     GPIOD_OUT_LOW);
1453 		if (IS_ERR(pdata->bus[i])) {
1454 			dev_err(&pdev->dev, "failed to get gpio %d\n", i);
1455 			return PTR_ERR(pdata->bus[i]);
1456 		}
1457 	}
1458 
1459 	if (pdata->no_wprotect)
1460 		mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
1461 
1462 	if (pdata->no_detect)
1463 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1464 
1465 	if (pdata->wprotect_invert)
1466 		mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
1467 
1468 	/* If we get -ENOENT we have no card detect GPIO line */
1469 	ret = mmc_gpiod_request_cd(mmc, "cd", 0, false, 0);
1470 	if (ret != -ENOENT) {
1471 		dev_err(&pdev->dev, "error requesting GPIO for CD %d\n",
1472 			ret);
1473 		return ret;
1474 	}
1475 
1476 	ret = mmc_gpiod_request_ro(host->mmc, "wp", 0, 0);
1477 	if (ret != -ENOENT) {
1478 		dev_err(&pdev->dev, "error requesting GPIO for WP %d\n",
1479 			ret);
1480 		return ret;
1481 	}
1482 
1483 	return 0;
1484 }
1485 
s3cmci_probe_dt(struct s3cmci_host * host)1486 static int s3cmci_probe_dt(struct s3cmci_host *host)
1487 {
1488 	struct platform_device *pdev = host->pdev;
1489 	struct s3c24xx_mci_pdata *pdata;
1490 	struct mmc_host *mmc = host->mmc;
1491 	int ret;
1492 
1493 	host->is2440 = (long) of_device_get_match_data(&pdev->dev);
1494 
1495 	ret = mmc_of_parse(mmc);
1496 	if (ret)
1497 		return ret;
1498 
1499 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1500 	if (!pdata)
1501 		return -ENOMEM;
1502 
1503 	pdev->dev.platform_data = pdata;
1504 
1505 	return 0;
1506 }
1507 
s3cmci_probe(struct platform_device * pdev)1508 static int s3cmci_probe(struct platform_device *pdev)
1509 {
1510 	struct s3cmci_host *host;
1511 	struct mmc_host	*mmc;
1512 	int ret;
1513 
1514 	mmc = mmc_alloc_host(sizeof(struct s3cmci_host), &pdev->dev);
1515 	if (!mmc) {
1516 		ret = -ENOMEM;
1517 		goto probe_out;
1518 	}
1519 
1520 	host = mmc_priv(mmc);
1521 	host->mmc 	= mmc;
1522 	host->pdev	= pdev;
1523 
1524 	if (pdev->dev.of_node)
1525 		ret = s3cmci_probe_dt(host);
1526 	else
1527 		ret = s3cmci_probe_pdata(host);
1528 
1529 	if (ret)
1530 		goto probe_free_host;
1531 
1532 	host->pdata = pdev->dev.platform_data;
1533 
1534 	spin_lock_init(&host->complete_lock);
1535 	tasklet_setup(&host->pio_tasklet, pio_tasklet);
1536 
1537 	if (host->is2440) {
1538 		host->sdiimsk	= S3C2440_SDIIMSK;
1539 		host->sdidata	= S3C2440_SDIDATA;
1540 		host->clk_div	= 1;
1541 	} else {
1542 		host->sdiimsk	= S3C2410_SDIIMSK;
1543 		host->sdidata	= S3C2410_SDIDATA;
1544 		host->clk_div	= 2;
1545 	}
1546 
1547 	host->complete_what 	= COMPLETION_NONE;
1548 	host->pio_active 	= XFER_NONE;
1549 
1550 	host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1551 	if (!host->mem) {
1552 		dev_err(&pdev->dev,
1553 			"failed to get io memory region resource.\n");
1554 
1555 		ret = -ENOENT;
1556 		goto probe_free_host;
1557 	}
1558 
1559 	host->mem = request_mem_region(host->mem->start,
1560 				       resource_size(host->mem), pdev->name);
1561 
1562 	if (!host->mem) {
1563 		dev_err(&pdev->dev, "failed to request io memory region.\n");
1564 		ret = -ENOENT;
1565 		goto probe_free_host;
1566 	}
1567 
1568 	host->base = ioremap(host->mem->start, resource_size(host->mem));
1569 	if (!host->base) {
1570 		dev_err(&pdev->dev, "failed to ioremap() io memory region.\n");
1571 		ret = -EINVAL;
1572 		goto probe_free_mem_region;
1573 	}
1574 
1575 	host->irq = platform_get_irq(pdev, 0);
1576 	if (host->irq <= 0) {
1577 		ret = -EINVAL;
1578 		goto probe_iounmap;
1579 	}
1580 
1581 	if (request_irq(host->irq, s3cmci_irq, IRQF_NO_AUTOEN, DRIVER_NAME, host)) {
1582 		dev_err(&pdev->dev, "failed to request mci interrupt.\n");
1583 		ret = -ENOENT;
1584 		goto probe_iounmap;
1585 	}
1586 
1587 	host->irq_state = false;
1588 
1589 	/* Depending on the dma state, get a DMA channel to use. */
1590 
1591 	if (s3cmci_host_usedma(host)) {
1592 		host->dma = dma_request_chan(&pdev->dev, "rx-tx");
1593 		ret = PTR_ERR_OR_ZERO(host->dma);
1594 		if (ret) {
1595 			dev_err(&pdev->dev, "cannot get DMA channel.\n");
1596 			goto probe_free_irq;
1597 		}
1598 	}
1599 
1600 	host->clk = clk_get(&pdev->dev, "sdi");
1601 	if (IS_ERR(host->clk)) {
1602 		dev_err(&pdev->dev, "failed to find clock source.\n");
1603 		ret = PTR_ERR(host->clk);
1604 		host->clk = NULL;
1605 		goto probe_free_dma;
1606 	}
1607 
1608 	ret = clk_prepare_enable(host->clk);
1609 	if (ret) {
1610 		dev_err(&pdev->dev, "failed to enable clock source.\n");
1611 		goto clk_free;
1612 	}
1613 
1614 	host->clk_rate = clk_get_rate(host->clk);
1615 
1616 	mmc->ops 	= &s3cmci_ops;
1617 	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
1618 #ifdef CONFIG_MMC_S3C_HW_SDIO_IRQ
1619 	mmc->caps	= MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
1620 #else
1621 	mmc->caps	= MMC_CAP_4_BIT_DATA;
1622 #endif
1623 	mmc->f_min 	= host->clk_rate / (host->clk_div * 256);
1624 	mmc->f_max 	= host->clk_rate / host->clk_div;
1625 
1626 	if (host->pdata->ocr_avail)
1627 		mmc->ocr_avail = host->pdata->ocr_avail;
1628 
1629 	mmc->max_blk_count	= 4095;
1630 	mmc->max_blk_size	= 4095;
1631 	mmc->max_req_size	= 4095 * 512;
1632 	mmc->max_seg_size	= mmc->max_req_size;
1633 
1634 	mmc->max_segs		= 128;
1635 
1636 	dbg(host, dbg_debug,
1637 	    "probe: mode:%s mapped mci_base:%p irq:%u irq_cd:%u dma:%p.\n",
1638 	    (host->is2440?"2440":""),
1639 	    host->base, host->irq, host->irq_cd, host->dma);
1640 
1641 	ret = s3cmci_cpufreq_register(host);
1642 	if (ret) {
1643 		dev_err(&pdev->dev, "failed to register cpufreq\n");
1644 		goto free_dmabuf;
1645 	}
1646 
1647 	ret = mmc_add_host(mmc);
1648 	if (ret) {
1649 		dev_err(&pdev->dev, "failed to add mmc host.\n");
1650 		goto free_cpufreq;
1651 	}
1652 
1653 	s3cmci_debugfs_attach(host);
1654 
1655 	platform_set_drvdata(pdev, mmc);
1656 	dev_info(&pdev->dev, "%s - using %s, %s SDIO IRQ\n", mmc_hostname(mmc),
1657 		 s3cmci_host_usedma(host) ? "dma" : "pio",
1658 		 mmc->caps & MMC_CAP_SDIO_IRQ ? "hw" : "sw");
1659 
1660 	return 0;
1661 
1662  free_cpufreq:
1663 	s3cmci_cpufreq_deregister(host);
1664 
1665  free_dmabuf:
1666 	clk_disable_unprepare(host->clk);
1667 
1668  clk_free:
1669 	clk_put(host->clk);
1670 
1671  probe_free_dma:
1672 	if (s3cmci_host_usedma(host))
1673 		dma_release_channel(host->dma);
1674 
1675  probe_free_irq:
1676 	free_irq(host->irq, host);
1677 
1678  probe_iounmap:
1679 	iounmap(host->base);
1680 
1681  probe_free_mem_region:
1682 	release_mem_region(host->mem->start, resource_size(host->mem));
1683 
1684  probe_free_host:
1685 	mmc_free_host(mmc);
1686 
1687  probe_out:
1688 	return ret;
1689 }
1690 
s3cmci_shutdown(struct platform_device * pdev)1691 static void s3cmci_shutdown(struct platform_device *pdev)
1692 {
1693 	struct mmc_host	*mmc = platform_get_drvdata(pdev);
1694 	struct s3cmci_host *host = mmc_priv(mmc);
1695 
1696 	if (host->irq_cd >= 0)
1697 		free_irq(host->irq_cd, host);
1698 
1699 	s3cmci_debugfs_remove(host);
1700 	s3cmci_cpufreq_deregister(host);
1701 	mmc_remove_host(mmc);
1702 	clk_disable_unprepare(host->clk);
1703 }
1704 
s3cmci_remove(struct platform_device * pdev)1705 static int s3cmci_remove(struct platform_device *pdev)
1706 {
1707 	struct mmc_host		*mmc  = platform_get_drvdata(pdev);
1708 	struct s3cmci_host	*host = mmc_priv(mmc);
1709 
1710 	s3cmci_shutdown(pdev);
1711 
1712 	clk_put(host->clk);
1713 
1714 	tasklet_disable(&host->pio_tasklet);
1715 
1716 	if (s3cmci_host_usedma(host))
1717 		dma_release_channel(host->dma);
1718 
1719 	free_irq(host->irq, host);
1720 
1721 	iounmap(host->base);
1722 	release_mem_region(host->mem->start, resource_size(host->mem));
1723 
1724 	mmc_free_host(mmc);
1725 	return 0;
1726 }
1727 
1728 static const struct of_device_id s3cmci_dt_match[] = {
1729 	{
1730 		.compatible = "samsung,s3c2410-sdi",
1731 		.data = (void *)0,
1732 	},
1733 	{
1734 		.compatible = "samsung,s3c2412-sdi",
1735 		.data = (void *)1,
1736 	},
1737 	{
1738 		.compatible = "samsung,s3c2440-sdi",
1739 		.data = (void *)1,
1740 	},
1741 	{ /* sentinel */ },
1742 };
1743 MODULE_DEVICE_TABLE(of, s3cmci_dt_match);
1744 
1745 static const struct platform_device_id s3cmci_driver_ids[] = {
1746 	{
1747 		.name	= "s3c2410-sdi",
1748 		.driver_data	= 0,
1749 	}, {
1750 		.name	= "s3c2412-sdi",
1751 		.driver_data	= 1,
1752 	}, {
1753 		.name	= "s3c2440-sdi",
1754 		.driver_data	= 1,
1755 	},
1756 	{ }
1757 };
1758 
1759 MODULE_DEVICE_TABLE(platform, s3cmci_driver_ids);
1760 
1761 static struct platform_driver s3cmci_driver = {
1762 	.driver	= {
1763 		.name	= "s3c-sdi",
1764 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1765 		.of_match_table = s3cmci_dt_match,
1766 	},
1767 	.id_table	= s3cmci_driver_ids,
1768 	.probe		= s3cmci_probe,
1769 	.remove		= s3cmci_remove,
1770 	.shutdown	= s3cmci_shutdown,
1771 };
1772 
1773 module_platform_driver(s3cmci_driver);
1774 
1775 MODULE_DESCRIPTION("Samsung S3C MMC/SD Card Interface driver");
1776 MODULE_LICENSE("GPL v2");
1777 MODULE_AUTHOR("Thomas Kleffel <tk@maintech.de>, Ben Dooks <ben-linux@fluff.org>");
1778