xref: /openbmc/linux/drivers/mmc/host/alcor.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2018 Oleksij Rempel <linux@rempel-privat.de>
4  *
5  * Driver for Alcor Micro AU6601 and AU6621 controllers
6  */
7 
8 /* Note: this driver was created without any documentation. Based
9  * on sniffing, testing and in some cases mimic of original driver.
10  * As soon as some one with documentation or more experience in SD/MMC, or
11  * reverse engineering then me, please review this driver and question every
12  * thing what I did. 2018 Oleksij Rempel <linux@rempel-privat.de>
13  */
14 
15 #include <linux/delay.h>
16 #include <linux/pci.h>
17 #include <linux/module.h>
18 #include <linux/io.h>
19 #include <linux/pm.h>
20 #include <linux/irq.h>
21 #include <linux/interrupt.h>
22 #include <linux/platform_device.h>
23 
24 #include <linux/mmc/host.h>
25 #include <linux/mmc/mmc.h>
26 
27 #include <linux/alcor_pci.h>
28 
29 enum alcor_cookie {
30 	COOKIE_UNMAPPED,
31 	COOKIE_PRE_MAPPED,
32 	COOKIE_MAPPED,
33 };
34 
35 struct alcor_pll_conf {
36 	unsigned int clk_src_freq;
37 	unsigned int clk_src_reg;
38 	unsigned int min_div;
39 	unsigned int max_div;
40 };
41 
42 struct alcor_sdmmc_host {
43 	struct  device *dev;
44 	struct alcor_pci_priv *alcor_pci;
45 
46 	struct mmc_request *mrq;
47 	struct mmc_command *cmd;
48 	struct mmc_data *data;
49 	unsigned int dma_on:1;
50 
51 	struct mutex cmd_mutex;
52 
53 	struct delayed_work timeout_work;
54 
55 	struct sg_mapping_iter sg_miter;	/* SG state for PIO */
56 	struct scatterlist *sg;
57 	unsigned int blocks;		/* remaining PIO blocks */
58 	int sg_count;
59 
60 	u32			irq_status_sd;
61 	unsigned char		cur_power_mode;
62 };
63 
64 static const struct alcor_pll_conf alcor_pll_cfg[] = {
65 	/* MHZ,		CLK src,		max div, min div */
66 	{ 31250000,	AU6601_CLK_31_25_MHZ,	1,	511},
67 	{ 48000000,	AU6601_CLK_48_MHZ,	1,	511},
68 	{125000000,	AU6601_CLK_125_MHZ,	1,	511},
69 	{384000000,	AU6601_CLK_384_MHZ,	1,	511},
70 };
71 
72 static inline void alcor_rmw8(struct alcor_sdmmc_host *host, unsigned int addr,
73 			       u8 clear, u8 set)
74 {
75 	struct alcor_pci_priv *priv = host->alcor_pci;
76 	u32 var;
77 
78 	var = alcor_read8(priv, addr);
79 	var &= ~clear;
80 	var |= set;
81 	alcor_write8(priv, var, addr);
82 }
83 
84 /* As soon as irqs are masked, some status updates may be missed.
85  * Use this with care.
86  */
87 static inline void alcor_mask_sd_irqs(struct alcor_sdmmc_host *host)
88 {
89 	struct alcor_pci_priv *priv = host->alcor_pci;
90 
91 	alcor_write32(priv, 0, AU6601_REG_INT_ENABLE);
92 }
93 
94 static inline void alcor_unmask_sd_irqs(struct alcor_sdmmc_host *host)
95 {
96 	struct alcor_pci_priv *priv = host->alcor_pci;
97 
98 	alcor_write32(priv, AU6601_INT_CMD_MASK | AU6601_INT_DATA_MASK |
99 		  AU6601_INT_CARD_INSERT | AU6601_INT_CARD_REMOVE |
100 		  AU6601_INT_OVER_CURRENT_ERR,
101 		  AU6601_REG_INT_ENABLE);
102 }
103 
104 static void alcor_reset(struct alcor_sdmmc_host *host, u8 val)
105 {
106 	struct alcor_pci_priv *priv = host->alcor_pci;
107 	int i;
108 
109 	alcor_write8(priv, val | AU6601_BUF_CTRL_RESET,
110 		      AU6601_REG_SW_RESET);
111 	for (i = 0; i < 100; i++) {
112 		if (!(alcor_read8(priv, AU6601_REG_SW_RESET) & val))
113 			return;
114 		udelay(50);
115 	}
116 	dev_err(host->dev, "%s: timeout\n", __func__);
117 }
118 
119 /*
120  * Perform DMA I/O of a single page.
121  */
122 static void alcor_data_set_dma(struct alcor_sdmmc_host *host)
123 {
124 	struct alcor_pci_priv *priv = host->alcor_pci;
125 	u32 addr;
126 
127 	if (!host->sg_count)
128 		return;
129 
130 	if (!host->sg) {
131 		dev_err(host->dev, "have blocks, but no SG\n");
132 		return;
133 	}
134 
135 	if (!sg_dma_len(host->sg)) {
136 		dev_err(host->dev, "DMA SG len == 0\n");
137 		return;
138 	}
139 
140 
141 	addr = (u32)sg_dma_address(host->sg);
142 
143 	alcor_write32(priv, addr, AU6601_REG_SDMA_ADDR);
144 	host->sg = sg_next(host->sg);
145 	host->sg_count--;
146 }
147 
148 static void alcor_trigger_data_transfer(struct alcor_sdmmc_host *host)
149 {
150 	struct alcor_pci_priv *priv = host->alcor_pci;
151 	struct mmc_data *data = host->data;
152 	u8 ctrl = 0;
153 
154 	if (data->flags & MMC_DATA_WRITE)
155 		ctrl |= AU6601_DATA_WRITE;
156 
157 	if (data->host_cookie == COOKIE_MAPPED) {
158 		/*
159 		 * For DMA transfers, this function is called just once,
160 		 * at the start of the operation. The hardware can only
161 		 * perform DMA I/O on a single page at a time, so here
162 		 * we kick off the transfer with the first page, and expect
163 		 * subsequent pages to be transferred upon IRQ events
164 		 * indicating that the single-page DMA was completed.
165 		 */
166 		alcor_data_set_dma(host);
167 		ctrl |= AU6601_DATA_DMA_MODE;
168 		host->dma_on = 1;
169 		alcor_write32(priv, data->sg_count * 0x1000,
170 			       AU6601_REG_BLOCK_SIZE);
171 	} else {
172 		/*
173 		 * For PIO transfers, we break down each operation
174 		 * into several sector-sized transfers. When one sector has
175 		 * complete, the IRQ handler will call this function again
176 		 * to kick off the transfer of the next sector.
177 		 */
178 		alcor_write32(priv, data->blksz, AU6601_REG_BLOCK_SIZE);
179 	}
180 
181 	alcor_write8(priv, ctrl | AU6601_DATA_START_XFER,
182 		      AU6601_DATA_XFER_CTRL);
183 }
184 
185 static void alcor_trf_block_pio(struct alcor_sdmmc_host *host, bool read)
186 {
187 	struct alcor_pci_priv *priv = host->alcor_pci;
188 	size_t blksize, len;
189 	u8 *buf;
190 
191 	if (!host->blocks)
192 		return;
193 
194 	if (host->dma_on) {
195 		dev_err(host->dev, "configured DMA but got PIO request.\n");
196 		return;
197 	}
198 
199 	if (!!(host->data->flags & MMC_DATA_READ) != read) {
200 		dev_err(host->dev, "got unexpected direction %i != %i\n",
201 			!!(host->data->flags & MMC_DATA_READ), read);
202 	}
203 
204 	if (!sg_miter_next(&host->sg_miter))
205 		return;
206 
207 	blksize = host->data->blksz;
208 	len = min(host->sg_miter.length, blksize);
209 
210 	dev_dbg(host->dev, "PIO, %s block size: 0x%zx\n",
211 		read ? "read" : "write", blksize);
212 
213 	host->sg_miter.consumed = len;
214 	host->blocks--;
215 
216 	buf = host->sg_miter.addr;
217 
218 	if (read)
219 		ioread32_rep(priv->iobase + AU6601_REG_BUFFER, buf, len >> 2);
220 	else
221 		iowrite32_rep(priv->iobase + AU6601_REG_BUFFER, buf, len >> 2);
222 
223 	sg_miter_stop(&host->sg_miter);
224 }
225 
226 static void alcor_prepare_sg_miter(struct alcor_sdmmc_host *host)
227 {
228 	unsigned int flags = SG_MITER_ATOMIC;
229 	struct mmc_data *data = host->data;
230 
231 	if (data->flags & MMC_DATA_READ)
232 		flags |= SG_MITER_TO_SG;
233 	else
234 		flags |= SG_MITER_FROM_SG;
235 	sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
236 }
237 
238 static void alcor_prepare_data(struct alcor_sdmmc_host *host,
239 			       struct mmc_command *cmd)
240 {
241 	struct alcor_pci_priv *priv = host->alcor_pci;
242 	struct mmc_data *data = cmd->data;
243 
244 	if (!data)
245 		return;
246 
247 
248 	host->data = data;
249 	host->data->bytes_xfered = 0;
250 	host->blocks = data->blocks;
251 	host->sg = data->sg;
252 	host->sg_count = data->sg_count;
253 	dev_dbg(host->dev, "prepare DATA: sg %i, blocks: %i\n",
254 			host->sg_count, host->blocks);
255 
256 	if (data->host_cookie != COOKIE_MAPPED)
257 		alcor_prepare_sg_miter(host);
258 
259 	alcor_write8(priv, 0, AU6601_DATA_XFER_CTRL);
260 }
261 
262 static void alcor_send_cmd(struct alcor_sdmmc_host *host,
263 			   struct mmc_command *cmd, bool set_timeout)
264 {
265 	struct alcor_pci_priv *priv = host->alcor_pci;
266 	unsigned long timeout = 0;
267 	u8 ctrl = 0;
268 
269 	host->cmd = cmd;
270 	alcor_prepare_data(host, cmd);
271 
272 	dev_dbg(host->dev, "send CMD. opcode: 0x%02x, arg; 0x%08x\n",
273 		cmd->opcode, cmd->arg);
274 	alcor_write8(priv, cmd->opcode | 0x40, AU6601_REG_CMD_OPCODE);
275 	alcor_write32be(priv, cmd->arg, AU6601_REG_CMD_ARG);
276 
277 	switch (mmc_resp_type(cmd)) {
278 	case MMC_RSP_NONE:
279 		ctrl = AU6601_CMD_NO_RESP;
280 		break;
281 	case MMC_RSP_R1:
282 		ctrl = AU6601_CMD_6_BYTE_CRC;
283 		break;
284 	case MMC_RSP_R1B:
285 		ctrl = AU6601_CMD_6_BYTE_CRC | AU6601_CMD_STOP_WAIT_RDY;
286 		break;
287 	case MMC_RSP_R2:
288 		ctrl = AU6601_CMD_17_BYTE_CRC;
289 		break;
290 	case MMC_RSP_R3:
291 		ctrl = AU6601_CMD_6_BYTE_WO_CRC;
292 		break;
293 	default:
294 		dev_err(host->dev, "%s: cmd->flag (0x%02x) is not valid\n",
295 			mmc_hostname(mmc_from_priv(host)), mmc_resp_type(cmd));
296 		break;
297 	}
298 
299 	if (set_timeout) {
300 		if (!cmd->data && cmd->busy_timeout)
301 			timeout = cmd->busy_timeout;
302 		else
303 			timeout = 10000;
304 
305 		schedule_delayed_work(&host->timeout_work,
306 				      msecs_to_jiffies(timeout));
307 	}
308 
309 	dev_dbg(host->dev, "xfer ctrl: 0x%02x; timeout: %lu\n", ctrl, timeout);
310 	alcor_write8(priv, ctrl | AU6601_CMD_START_XFER,
311 				 AU6601_CMD_XFER_CTRL);
312 }
313 
314 static void alcor_request_complete(struct alcor_sdmmc_host *host,
315 				   bool cancel_timeout)
316 {
317 	struct mmc_request *mrq;
318 
319 	/*
320 	 * If this work gets rescheduled while running, it will
321 	 * be run again afterwards but without any active request.
322 	 */
323 	if (!host->mrq)
324 		return;
325 
326 	if (cancel_timeout)
327 		cancel_delayed_work(&host->timeout_work);
328 
329 	mrq = host->mrq;
330 
331 	host->mrq = NULL;
332 	host->cmd = NULL;
333 	host->data = NULL;
334 	host->dma_on = 0;
335 
336 	mmc_request_done(mmc_from_priv(host), mrq);
337 }
338 
339 static void alcor_finish_data(struct alcor_sdmmc_host *host)
340 {
341 	struct mmc_data *data;
342 
343 	data = host->data;
344 	host->data = NULL;
345 	host->dma_on = 0;
346 
347 	/*
348 	 * The specification states that the block count register must
349 	 * be updated, but it does not specify at what point in the
350 	 * data flow. That makes the register entirely useless to read
351 	 * back so we have to assume that nothing made it to the card
352 	 * in the event of an error.
353 	 */
354 	if (data->error)
355 		data->bytes_xfered = 0;
356 	else
357 		data->bytes_xfered = data->blksz * data->blocks;
358 
359 	/*
360 	 * Need to send CMD12 if -
361 	 * a) open-ended multiblock transfer (no CMD23)
362 	 * b) error in multiblock transfer
363 	 */
364 	if (data->stop &&
365 	    (data->error ||
366 	     !host->mrq->sbc)) {
367 
368 		/*
369 		 * The controller needs a reset of internal state machines
370 		 * upon error conditions.
371 		 */
372 		if (data->error)
373 			alcor_reset(host, AU6601_RESET_CMD | AU6601_RESET_DATA);
374 
375 		alcor_unmask_sd_irqs(host);
376 		alcor_send_cmd(host, data->stop, false);
377 		return;
378 	}
379 
380 	alcor_request_complete(host, 1);
381 }
382 
383 static void alcor_err_irq(struct alcor_sdmmc_host *host, u32 intmask)
384 {
385 	dev_dbg(host->dev, "ERR IRQ %x\n", intmask);
386 
387 	if (host->cmd) {
388 		if (intmask & AU6601_INT_CMD_TIMEOUT_ERR)
389 			host->cmd->error = -ETIMEDOUT;
390 		else
391 			host->cmd->error = -EILSEQ;
392 	}
393 
394 	if (host->data) {
395 		if (intmask & AU6601_INT_DATA_TIMEOUT_ERR)
396 			host->data->error = -ETIMEDOUT;
397 		else
398 			host->data->error = -EILSEQ;
399 
400 		host->data->bytes_xfered = 0;
401 	}
402 
403 	alcor_reset(host, AU6601_RESET_CMD | AU6601_RESET_DATA);
404 	alcor_request_complete(host, 1);
405 }
406 
407 static int alcor_cmd_irq_done(struct alcor_sdmmc_host *host, u32 intmask)
408 {
409 	struct alcor_pci_priv *priv = host->alcor_pci;
410 
411 	intmask &= AU6601_INT_CMD_END;
412 
413 	if (!intmask)
414 		return true;
415 
416 	/* got CMD_END but no CMD is in progress, wake thread an process the
417 	 * error
418 	 */
419 	if (!host->cmd)
420 		return false;
421 
422 	if (host->cmd->flags & MMC_RSP_PRESENT) {
423 		struct mmc_command *cmd = host->cmd;
424 
425 		cmd->resp[0] = alcor_read32be(priv, AU6601_REG_CMD_RSP0);
426 		dev_dbg(host->dev, "RSP0: 0x%04x\n", cmd->resp[0]);
427 		if (host->cmd->flags & MMC_RSP_136) {
428 			cmd->resp[1] =
429 				alcor_read32be(priv, AU6601_REG_CMD_RSP1);
430 			cmd->resp[2] =
431 				alcor_read32be(priv, AU6601_REG_CMD_RSP2);
432 			cmd->resp[3] =
433 				alcor_read32be(priv, AU6601_REG_CMD_RSP3);
434 			dev_dbg(host->dev, "RSP1,2,3: 0x%04x 0x%04x 0x%04x\n",
435 				cmd->resp[1], cmd->resp[2], cmd->resp[3]);
436 		}
437 
438 	}
439 
440 	host->cmd->error = 0;
441 
442 	/* Processed actual command. */
443 	if (!host->data)
444 		return false;
445 
446 	alcor_trigger_data_transfer(host);
447 	host->cmd = NULL;
448 	return true;
449 }
450 
451 static void alcor_cmd_irq_thread(struct alcor_sdmmc_host *host, u32 intmask)
452 {
453 	intmask &= AU6601_INT_CMD_END;
454 
455 	if (!intmask)
456 		return;
457 
458 	if (!host->cmd && intmask & AU6601_INT_CMD_END) {
459 		dev_dbg(host->dev, "Got command interrupt 0x%08x even though no command operation was in progress.\n",
460 			intmask);
461 	}
462 
463 	/* Processed actual command. */
464 	if (!host->data)
465 		alcor_request_complete(host, 1);
466 	else
467 		alcor_trigger_data_transfer(host);
468 	host->cmd = NULL;
469 }
470 
471 static int alcor_data_irq_done(struct alcor_sdmmc_host *host, u32 intmask)
472 {
473 	u32 tmp;
474 
475 	intmask &= AU6601_INT_DATA_MASK;
476 
477 	/* nothing here to do */
478 	if (!intmask)
479 		return 1;
480 
481 	/* we was too fast and got DATA_END after it was processed?
482 	 * lets ignore it for now.
483 	 */
484 	if (!host->data && intmask == AU6601_INT_DATA_END)
485 		return 1;
486 
487 	/* looks like an error, so lets handle it. */
488 	if (!host->data)
489 		return 0;
490 
491 	tmp = intmask & (AU6601_INT_READ_BUF_RDY | AU6601_INT_WRITE_BUF_RDY
492 			 | AU6601_INT_DMA_END);
493 	switch (tmp) {
494 	case 0:
495 		break;
496 	case AU6601_INT_READ_BUF_RDY:
497 		alcor_trf_block_pio(host, true);
498 		return 1;
499 	case AU6601_INT_WRITE_BUF_RDY:
500 		alcor_trf_block_pio(host, false);
501 		return 1;
502 	case AU6601_INT_DMA_END:
503 		if (!host->sg_count)
504 			break;
505 
506 		alcor_data_set_dma(host);
507 		break;
508 	default:
509 		dev_err(host->dev, "Got READ_BUF_RDY and WRITE_BUF_RDY at same time\n");
510 		break;
511 	}
512 
513 	if (intmask & AU6601_INT_DATA_END) {
514 		if (!host->dma_on && host->blocks) {
515 			alcor_trigger_data_transfer(host);
516 			return 1;
517 		} else {
518 			return 0;
519 		}
520 	}
521 
522 	return 1;
523 }
524 
525 static void alcor_data_irq_thread(struct alcor_sdmmc_host *host, u32 intmask)
526 {
527 	intmask &= AU6601_INT_DATA_MASK;
528 
529 	if (!intmask)
530 		return;
531 
532 	if (!host->data) {
533 		dev_dbg(host->dev, "Got data interrupt 0x%08x even though no data operation was in progress.\n",
534 			intmask);
535 		alcor_reset(host, AU6601_RESET_DATA);
536 		return;
537 	}
538 
539 	if (alcor_data_irq_done(host, intmask))
540 		return;
541 
542 	if ((intmask & AU6601_INT_DATA_END) || !host->blocks ||
543 	    (host->dma_on && !host->sg_count))
544 		alcor_finish_data(host);
545 }
546 
547 static void alcor_cd_irq(struct alcor_sdmmc_host *host, u32 intmask)
548 {
549 	dev_dbg(host->dev, "card %s\n",
550 		intmask & AU6601_INT_CARD_REMOVE ? "removed" : "inserted");
551 
552 	if (host->mrq) {
553 		dev_dbg(host->dev, "cancel all pending tasks.\n");
554 
555 		if (host->data)
556 			host->data->error = -ENOMEDIUM;
557 
558 		if (host->cmd)
559 			host->cmd->error = -ENOMEDIUM;
560 		else
561 			host->mrq->cmd->error = -ENOMEDIUM;
562 
563 		alcor_request_complete(host, 1);
564 	}
565 
566 	mmc_detect_change(mmc_from_priv(host), msecs_to_jiffies(1));
567 }
568 
569 static irqreturn_t alcor_irq_thread(int irq, void *d)
570 {
571 	struct alcor_sdmmc_host *host = d;
572 	irqreturn_t ret = IRQ_HANDLED;
573 	u32 intmask, tmp;
574 
575 	mutex_lock(&host->cmd_mutex);
576 
577 	intmask = host->irq_status_sd;
578 
579 	/* some thing bad */
580 	if (unlikely(!intmask || AU6601_INT_ALL_MASK == intmask)) {
581 		dev_dbg(host->dev, "unexpected IRQ: 0x%04x\n", intmask);
582 		ret = IRQ_NONE;
583 		goto exit;
584 	}
585 
586 	tmp = intmask & (AU6601_INT_CMD_MASK | AU6601_INT_DATA_MASK);
587 	if (tmp) {
588 		if (tmp & AU6601_INT_ERROR_MASK)
589 			alcor_err_irq(host, tmp);
590 		else {
591 			alcor_cmd_irq_thread(host, tmp);
592 			alcor_data_irq_thread(host, tmp);
593 		}
594 		intmask &= ~(AU6601_INT_CMD_MASK | AU6601_INT_DATA_MASK);
595 	}
596 
597 	if (intmask & (AU6601_INT_CARD_INSERT | AU6601_INT_CARD_REMOVE)) {
598 		alcor_cd_irq(host, intmask);
599 		intmask &= ~(AU6601_INT_CARD_INSERT | AU6601_INT_CARD_REMOVE);
600 	}
601 
602 	if (intmask & AU6601_INT_OVER_CURRENT_ERR) {
603 		dev_warn(host->dev,
604 			 "warning: over current detected!\n");
605 		intmask &= ~AU6601_INT_OVER_CURRENT_ERR;
606 	}
607 
608 	if (intmask)
609 		dev_dbg(host->dev, "got not handled IRQ: 0x%04x\n", intmask);
610 
611 exit:
612 	mutex_unlock(&host->cmd_mutex);
613 	alcor_unmask_sd_irqs(host);
614 	return ret;
615 }
616 
617 
618 static irqreturn_t alcor_irq(int irq, void *d)
619 {
620 	struct alcor_sdmmc_host *host = d;
621 	struct alcor_pci_priv *priv = host->alcor_pci;
622 	u32 status, tmp;
623 	irqreturn_t ret;
624 	int cmd_done, data_done;
625 
626 	status = alcor_read32(priv, AU6601_REG_INT_STATUS);
627 	if (!status)
628 		return IRQ_NONE;
629 
630 	alcor_write32(priv, status, AU6601_REG_INT_STATUS);
631 
632 	tmp = status & (AU6601_INT_READ_BUF_RDY | AU6601_INT_WRITE_BUF_RDY
633 			| AU6601_INT_DATA_END | AU6601_INT_DMA_END
634 			| AU6601_INT_CMD_END);
635 	if (tmp == status) {
636 		cmd_done = alcor_cmd_irq_done(host, tmp);
637 		data_done = alcor_data_irq_done(host, tmp);
638 		/* use fast path for simple tasks */
639 		if (cmd_done && data_done) {
640 			ret = IRQ_HANDLED;
641 			goto alcor_irq_done;
642 		}
643 	}
644 
645 	host->irq_status_sd = status;
646 	ret = IRQ_WAKE_THREAD;
647 	alcor_mask_sd_irqs(host);
648 alcor_irq_done:
649 	return ret;
650 }
651 
652 static void alcor_set_clock(struct alcor_sdmmc_host *host, unsigned int clock)
653 {
654 	struct alcor_pci_priv *priv = host->alcor_pci;
655 	int i, diff = 0x7fffffff, tmp_clock = 0;
656 	u16 clk_src = 0;
657 	u8 clk_div = 0;
658 
659 	if (clock == 0) {
660 		alcor_write16(priv, 0, AU6601_CLK_SELECT);
661 		return;
662 	}
663 
664 	for (i = 0; i < ARRAY_SIZE(alcor_pll_cfg); i++) {
665 		unsigned int tmp_div, tmp_diff;
666 		const struct alcor_pll_conf *cfg = &alcor_pll_cfg[i];
667 
668 		tmp_div = DIV_ROUND_UP(cfg->clk_src_freq, clock);
669 		if (cfg->min_div > tmp_div || tmp_div > cfg->max_div)
670 			continue;
671 
672 		tmp_clock = DIV_ROUND_UP(cfg->clk_src_freq, tmp_div);
673 		tmp_diff = abs(clock - tmp_clock);
674 
675 		if (tmp_diff < diff) {
676 			diff = tmp_diff;
677 			clk_src = cfg->clk_src_reg;
678 			clk_div = tmp_div;
679 		}
680 	}
681 
682 	clk_src |= ((clk_div - 1) << 8);
683 	clk_src |= AU6601_CLK_ENABLE;
684 
685 	dev_dbg(host->dev, "set freq %d cal freq %d, use div %d, mod %x\n",
686 			clock, tmp_clock, clk_div, clk_src);
687 
688 	alcor_write16(priv, clk_src, AU6601_CLK_SELECT);
689 
690 }
691 
692 static void alcor_set_timing(struct mmc_host *mmc, struct mmc_ios *ios)
693 {
694 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
695 
696 	if (ios->timing == MMC_TIMING_LEGACY) {
697 		alcor_rmw8(host, AU6601_CLK_DELAY,
698 			    AU6601_CLK_POSITIVE_EDGE_ALL, 0);
699 	} else {
700 		alcor_rmw8(host, AU6601_CLK_DELAY,
701 			    0, AU6601_CLK_POSITIVE_EDGE_ALL);
702 	}
703 }
704 
705 static void alcor_set_bus_width(struct mmc_host *mmc, struct mmc_ios *ios)
706 {
707 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
708 	struct alcor_pci_priv *priv = host->alcor_pci;
709 
710 	if (ios->bus_width == MMC_BUS_WIDTH_1) {
711 		alcor_write8(priv, 0, AU6601_REG_BUS_CTRL);
712 	} else if (ios->bus_width == MMC_BUS_WIDTH_4) {
713 		alcor_write8(priv, AU6601_BUS_WIDTH_4BIT,
714 			      AU6601_REG_BUS_CTRL);
715 	} else
716 		dev_err(host->dev, "Unknown BUS mode\n");
717 
718 }
719 
720 static int alcor_card_busy(struct mmc_host *mmc)
721 {
722 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
723 	struct alcor_pci_priv *priv = host->alcor_pci;
724 	u8 status;
725 
726 	/* Check whether dat[0:3] low */
727 	status = alcor_read8(priv, AU6601_DATA_PIN_STATE);
728 
729 	return !(status & AU6601_BUS_STAT_DAT_MASK);
730 }
731 
732 static int alcor_get_cd(struct mmc_host *mmc)
733 {
734 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
735 	struct alcor_pci_priv *priv = host->alcor_pci;
736 	u8 detect;
737 
738 	detect = alcor_read8(priv, AU6601_DETECT_STATUS)
739 		& AU6601_DETECT_STATUS_M;
740 	/* check if card is present then send command and data */
741 	return (detect == AU6601_SD_DETECTED);
742 }
743 
744 static int alcor_get_ro(struct mmc_host *mmc)
745 {
746 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
747 	struct alcor_pci_priv *priv = host->alcor_pci;
748 	u8 status;
749 
750 	/* get write protect pin status */
751 	status = alcor_read8(priv, AU6601_INTERFACE_MODE_CTRL);
752 
753 	return !!(status & AU6601_SD_CARD_WP);
754 }
755 
756 static void alcor_request(struct mmc_host *mmc, struct mmc_request *mrq)
757 {
758 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
759 
760 	mutex_lock(&host->cmd_mutex);
761 
762 	host->mrq = mrq;
763 
764 	/* check if card is present then send command and data */
765 	if (alcor_get_cd(mmc))
766 		alcor_send_cmd(host, mrq->cmd, true);
767 	else {
768 		mrq->cmd->error = -ENOMEDIUM;
769 		alcor_request_complete(host, 1);
770 	}
771 
772 	mutex_unlock(&host->cmd_mutex);
773 }
774 
775 static void alcor_pre_req(struct mmc_host *mmc,
776 			   struct mmc_request *mrq)
777 {
778 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
779 	struct mmc_data *data = mrq->data;
780 	struct mmc_command *cmd = mrq->cmd;
781 	struct scatterlist *sg;
782 	unsigned int i, sg_len;
783 
784 	if (!data || !cmd)
785 		return;
786 
787 	data->host_cookie = COOKIE_UNMAPPED;
788 
789 	/* FIXME: looks like the DMA engine works only with CMD18 */
790 	if (cmd->opcode != MMC_READ_MULTIPLE_BLOCK
791 			&& cmd->opcode != MMC_WRITE_MULTIPLE_BLOCK)
792 		return;
793 	/*
794 	 * We don't do DMA on "complex" transfers, i.e. with
795 	 * non-word-aligned buffers or lengths. A future improvement
796 	 * could be made to use temporary DMA bounce-buffers when these
797 	 * requirements are not met.
798 	 *
799 	 * Also, we don't bother with all the DMA setup overhead for
800 	 * short transfers.
801 	 */
802 	if (data->blocks * data->blksz < AU6601_MAX_DMA_BLOCK_SIZE)
803 		return;
804 
805 	if (data->blksz & 3)
806 		return;
807 
808 	for_each_sg(data->sg, sg, data->sg_len, i) {
809 		if (sg->length != AU6601_MAX_DMA_BLOCK_SIZE)
810 			return;
811 		if (sg->offset != 0)
812 			return;
813 	}
814 
815 	/* This data might be unmapped at this time */
816 
817 	sg_len = dma_map_sg(host->dev, data->sg, data->sg_len,
818 			    mmc_get_dma_dir(data));
819 	if (sg_len)
820 		data->host_cookie = COOKIE_MAPPED;
821 
822 	data->sg_count = sg_len;
823 }
824 
825 static void alcor_post_req(struct mmc_host *mmc,
826 			    struct mmc_request *mrq,
827 			    int err)
828 {
829 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
830 	struct mmc_data *data = mrq->data;
831 
832 	if (!data)
833 		return;
834 
835 	if (data->host_cookie == COOKIE_MAPPED) {
836 		dma_unmap_sg(host->dev,
837 			     data->sg,
838 			     data->sg_len,
839 			     mmc_get_dma_dir(data));
840 	}
841 
842 	data->host_cookie = COOKIE_UNMAPPED;
843 }
844 
845 static void alcor_set_power_mode(struct mmc_host *mmc, struct mmc_ios *ios)
846 {
847 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
848 	struct alcor_pci_priv *priv = host->alcor_pci;
849 
850 	switch (ios->power_mode) {
851 	case MMC_POWER_OFF:
852 		alcor_set_clock(host, ios->clock);
853 		/* set all pins to input */
854 		alcor_write8(priv, 0, AU6601_OUTPUT_ENABLE);
855 		/* turn of VDD */
856 		alcor_write8(priv, 0, AU6601_POWER_CONTROL);
857 		break;
858 	case MMC_POWER_UP:
859 		break;
860 	case MMC_POWER_ON:
861 		/* This is most trickiest part. The order and timings of
862 		 * instructions seems to play important role. Any changes may
863 		 * confuse internal state engine if this HW.
864 		 * FIXME: If we will ever get access to documentation, then this
865 		 * part should be reviewed again.
866 		 */
867 
868 		/* enable SD card mode */
869 		alcor_write8(priv, AU6601_SD_CARD,
870 			      AU6601_ACTIVE_CTRL);
871 		/* set signal voltage to 3.3V */
872 		alcor_write8(priv, 0, AU6601_OPT);
873 		/* no documentation about clk delay, for now just try to mimic
874 		 * original driver.
875 		 */
876 		alcor_write8(priv, 0x20, AU6601_CLK_DELAY);
877 		/* set BUS width to 1 bit */
878 		alcor_write8(priv, 0, AU6601_REG_BUS_CTRL);
879 		/* set CLK first time */
880 		alcor_set_clock(host, ios->clock);
881 		/* power on VDD */
882 		alcor_write8(priv, AU6601_SD_CARD,
883 			      AU6601_POWER_CONTROL);
884 		/* wait until the CLK will get stable */
885 		mdelay(20);
886 		/* set CLK again, mimic original driver. */
887 		alcor_set_clock(host, ios->clock);
888 
889 		/* enable output */
890 		alcor_write8(priv, AU6601_SD_CARD,
891 			      AU6601_OUTPUT_ENABLE);
892 		/* The clk will not work on au6621. We need to trigger data
893 		 * transfer.
894 		 */
895 		alcor_write8(priv, AU6601_DATA_WRITE,
896 			      AU6601_DATA_XFER_CTRL);
897 		/* configure timeout. Not clear what exactly it means. */
898 		alcor_write8(priv, 0x7d, AU6601_TIME_OUT_CTRL);
899 		mdelay(100);
900 		break;
901 	default:
902 		dev_err(host->dev, "Unknown power parameter\n");
903 	}
904 }
905 
906 static void alcor_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
907 {
908 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
909 
910 	mutex_lock(&host->cmd_mutex);
911 
912 	dev_dbg(host->dev, "set ios. bus width: %x, power mode: %x\n",
913 		ios->bus_width, ios->power_mode);
914 
915 	if (ios->power_mode != host->cur_power_mode) {
916 		alcor_set_power_mode(mmc, ios);
917 		host->cur_power_mode = ios->power_mode;
918 	} else {
919 		alcor_set_timing(mmc, ios);
920 		alcor_set_bus_width(mmc, ios);
921 		alcor_set_clock(host, ios->clock);
922 	}
923 
924 	mutex_unlock(&host->cmd_mutex);
925 }
926 
927 static int alcor_signal_voltage_switch(struct mmc_host *mmc,
928 				       struct mmc_ios *ios)
929 {
930 	struct alcor_sdmmc_host *host = mmc_priv(mmc);
931 
932 	mutex_lock(&host->cmd_mutex);
933 
934 	switch (ios->signal_voltage) {
935 	case MMC_SIGNAL_VOLTAGE_330:
936 		alcor_rmw8(host, AU6601_OPT, AU6601_OPT_SD_18V, 0);
937 		break;
938 	case MMC_SIGNAL_VOLTAGE_180:
939 		alcor_rmw8(host, AU6601_OPT, 0, AU6601_OPT_SD_18V);
940 		break;
941 	default:
942 		/* No signal voltage switch required */
943 		break;
944 	}
945 
946 	mutex_unlock(&host->cmd_mutex);
947 	return 0;
948 }
949 
950 static const struct mmc_host_ops alcor_sdc_ops = {
951 	.card_busy	= alcor_card_busy,
952 	.get_cd		= alcor_get_cd,
953 	.get_ro		= alcor_get_ro,
954 	.post_req	= alcor_post_req,
955 	.pre_req	= alcor_pre_req,
956 	.request	= alcor_request,
957 	.set_ios	= alcor_set_ios,
958 	.start_signal_voltage_switch = alcor_signal_voltage_switch,
959 };
960 
961 static void alcor_timeout_timer(struct work_struct *work)
962 {
963 	struct delayed_work *d = to_delayed_work(work);
964 	struct alcor_sdmmc_host *host = container_of(d, struct alcor_sdmmc_host,
965 						timeout_work);
966 	mutex_lock(&host->cmd_mutex);
967 
968 	dev_dbg(host->dev, "triggered timeout\n");
969 	if (host->mrq) {
970 		dev_err(host->dev, "Timeout waiting for hardware interrupt.\n");
971 
972 		if (host->data) {
973 			host->data->error = -ETIMEDOUT;
974 		} else {
975 			if (host->cmd)
976 				host->cmd->error = -ETIMEDOUT;
977 			else
978 				host->mrq->cmd->error = -ETIMEDOUT;
979 		}
980 
981 		alcor_reset(host, AU6601_RESET_CMD | AU6601_RESET_DATA);
982 		alcor_request_complete(host, 0);
983 	}
984 
985 	mutex_unlock(&host->cmd_mutex);
986 }
987 
988 static void alcor_hw_init(struct alcor_sdmmc_host *host)
989 {
990 	struct alcor_pci_priv *priv = host->alcor_pci;
991 	struct alcor_dev_cfg *cfg = priv->cfg;
992 
993 	/* FIXME: This part is a mimics HW init of original driver.
994 	 * If we will ever get access to documentation, then this part
995 	 * should be reviewed again.
996 	 */
997 
998 	/* reset command state engine */
999 	alcor_reset(host, AU6601_RESET_CMD);
1000 
1001 	alcor_write8(priv, 0, AU6601_DMA_BOUNDARY);
1002 	/* enable sd card mode */
1003 	alcor_write8(priv, AU6601_SD_CARD, AU6601_ACTIVE_CTRL);
1004 
1005 	/* set BUS width to 1 bit */
1006 	alcor_write8(priv, 0, AU6601_REG_BUS_CTRL);
1007 
1008 	/* reset data state engine */
1009 	alcor_reset(host, AU6601_RESET_DATA);
1010 	/* Not sure if a voodoo with AU6601_DMA_BOUNDARY is really needed */
1011 	alcor_write8(priv, 0, AU6601_DMA_BOUNDARY);
1012 
1013 	alcor_write8(priv, 0, AU6601_INTERFACE_MODE_CTRL);
1014 	/* not clear what we are doing here. */
1015 	alcor_write8(priv, 0x44, AU6601_PAD_DRIVE0);
1016 	alcor_write8(priv, 0x44, AU6601_PAD_DRIVE1);
1017 	alcor_write8(priv, 0x00, AU6601_PAD_DRIVE2);
1018 
1019 	/* for 6601 - dma_boundary; for 6621 - dma_page_cnt
1020 	 * exact meaning of this register is not clear.
1021 	 */
1022 	alcor_write8(priv, cfg->dma, AU6601_DMA_BOUNDARY);
1023 
1024 	/* make sure all pins are set to input and VDD is off */
1025 	alcor_write8(priv, 0, AU6601_OUTPUT_ENABLE);
1026 	alcor_write8(priv, 0, AU6601_POWER_CONTROL);
1027 
1028 	alcor_write8(priv, AU6601_DETECT_EN, AU6601_DETECT_STATUS);
1029 	/* now we should be safe to enable IRQs */
1030 	alcor_unmask_sd_irqs(host);
1031 }
1032 
1033 static void alcor_hw_uninit(struct alcor_sdmmc_host *host)
1034 {
1035 	struct alcor_pci_priv *priv = host->alcor_pci;
1036 
1037 	alcor_mask_sd_irqs(host);
1038 	alcor_reset(host, AU6601_RESET_CMD | AU6601_RESET_DATA);
1039 
1040 	alcor_write8(priv, 0, AU6601_DETECT_STATUS);
1041 
1042 	alcor_write8(priv, 0, AU6601_OUTPUT_ENABLE);
1043 	alcor_write8(priv, 0, AU6601_POWER_CONTROL);
1044 
1045 	alcor_write8(priv, 0, AU6601_OPT);
1046 }
1047 
1048 static void alcor_init_mmc(struct alcor_sdmmc_host *host)
1049 {
1050 	struct mmc_host *mmc = mmc_from_priv(host);
1051 
1052 	mmc->f_min = AU6601_MIN_CLOCK;
1053 	mmc->f_max = AU6601_MAX_CLOCK;
1054 	mmc->ocr_avail = MMC_VDD_33_34;
1055 	mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SD_HIGHSPEED
1056 		| MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | MMC_CAP_UHS_SDR50
1057 		| MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50;
1058 	mmc->caps2 = MMC_CAP2_NO_SDIO;
1059 	mmc->ops = &alcor_sdc_ops;
1060 
1061 	/* The hardware does DMA data transfer of 4096 bytes to/from a single
1062 	 * buffer address. Scatterlists are not supported at the hardware
1063 	 * level, however we can work with them at the driver level,
1064 	 * provided that each segment is exactly 4096 bytes in size.
1065 	 * Upon DMA completion of a single segment (signalled via IRQ), we
1066 	 * immediately proceed to transfer the next segment from the
1067 	 * scatterlist.
1068 	 *
1069 	 * The overall request is limited to 240 sectors, matching the
1070 	 * original vendor driver.
1071 	 */
1072 	mmc->max_segs = AU6601_MAX_DMA_SEGMENTS;
1073 	mmc->max_seg_size = AU6601_MAX_DMA_BLOCK_SIZE;
1074 	mmc->max_blk_count = 240;
1075 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
1076 	dma_set_max_seg_size(host->dev, mmc->max_seg_size);
1077 }
1078 
1079 static int alcor_pci_sdmmc_drv_probe(struct platform_device *pdev)
1080 {
1081 	struct alcor_pci_priv *priv = pdev->dev.platform_data;
1082 	struct mmc_host *mmc;
1083 	struct alcor_sdmmc_host *host;
1084 	int ret;
1085 
1086 	mmc = mmc_alloc_host(sizeof(*host), &pdev->dev);
1087 	if (!mmc) {
1088 		dev_err(&pdev->dev, "Can't allocate MMC\n");
1089 		return -ENOMEM;
1090 	}
1091 
1092 	host = mmc_priv(mmc);
1093 	host->dev = &pdev->dev;
1094 	host->cur_power_mode = MMC_POWER_UNDEFINED;
1095 	host->alcor_pci = priv;
1096 
1097 	/* make sure irqs are disabled */
1098 	alcor_write32(priv, 0, AU6601_REG_INT_ENABLE);
1099 	alcor_write32(priv, 0, AU6601_MS_INT_ENABLE);
1100 
1101 	ret = devm_request_threaded_irq(&pdev->dev, priv->irq,
1102 			alcor_irq, alcor_irq_thread, IRQF_SHARED,
1103 			DRV_NAME_ALCOR_PCI_SDMMC, host);
1104 
1105 	if (ret) {
1106 		dev_err(&pdev->dev, "Failed to get irq for data line\n");
1107 		goto free_host;
1108 	}
1109 
1110 	mutex_init(&host->cmd_mutex);
1111 	INIT_DELAYED_WORK(&host->timeout_work, alcor_timeout_timer);
1112 
1113 	alcor_init_mmc(host);
1114 	alcor_hw_init(host);
1115 
1116 	dev_set_drvdata(&pdev->dev, host);
1117 	mmc_add_host(mmc);
1118 	return 0;
1119 
1120 free_host:
1121 	mmc_free_host(mmc);
1122 	return ret;
1123 }
1124 
1125 static int alcor_pci_sdmmc_drv_remove(struct platform_device *pdev)
1126 {
1127 	struct alcor_sdmmc_host *host = dev_get_drvdata(&pdev->dev);
1128 	struct mmc_host *mmc = mmc_from_priv(host);
1129 
1130 	if (cancel_delayed_work_sync(&host->timeout_work))
1131 		alcor_request_complete(host, 0);
1132 
1133 	alcor_hw_uninit(host);
1134 	mmc_remove_host(mmc);
1135 	mmc_free_host(mmc);
1136 
1137 	return 0;
1138 }
1139 
1140 #ifdef CONFIG_PM_SLEEP
1141 static int alcor_pci_sdmmc_suspend(struct device *dev)
1142 {
1143 	struct alcor_sdmmc_host *host = dev_get_drvdata(dev);
1144 
1145 	if (cancel_delayed_work_sync(&host->timeout_work))
1146 		alcor_request_complete(host, 0);
1147 
1148 	alcor_hw_uninit(host);
1149 
1150 	return 0;
1151 }
1152 
1153 static int alcor_pci_sdmmc_resume(struct device *dev)
1154 {
1155 	struct alcor_sdmmc_host *host = dev_get_drvdata(dev);
1156 
1157 	alcor_hw_init(host);
1158 
1159 	return 0;
1160 }
1161 #endif /* CONFIG_PM_SLEEP */
1162 
1163 static SIMPLE_DEV_PM_OPS(alcor_mmc_pm_ops, alcor_pci_sdmmc_suspend,
1164 			 alcor_pci_sdmmc_resume);
1165 
1166 static const struct platform_device_id alcor_pci_sdmmc_ids[] = {
1167 	{
1168 		.name = DRV_NAME_ALCOR_PCI_SDMMC,
1169 	}, {
1170 		/* sentinel */
1171 	}
1172 };
1173 MODULE_DEVICE_TABLE(platform, alcor_pci_sdmmc_ids);
1174 
1175 static struct platform_driver alcor_pci_sdmmc_driver = {
1176 	.probe		= alcor_pci_sdmmc_drv_probe,
1177 	.remove		= alcor_pci_sdmmc_drv_remove,
1178 	.id_table	= alcor_pci_sdmmc_ids,
1179 	.driver		= {
1180 		.name	= DRV_NAME_ALCOR_PCI_SDMMC,
1181 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1182 		.pm	= &alcor_mmc_pm_ops
1183 	},
1184 };
1185 module_platform_driver(alcor_pci_sdmmc_driver);
1186 
1187 MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>");
1188 MODULE_DESCRIPTION("PCI driver for Alcor Micro AU6601 Secure Digital Host Controller Interface");
1189 MODULE_LICENSE("GPL");
1190