xref: /openbmc/linux/drivers/mmc/host/mmci.c (revision 8fdff1dc)
1 /*
2  *  linux/drivers/mmc/host/mmci.c - ARM PrimeCell MMCI PL180/1 driver
3  *
4  *  Copyright (C) 2003 Deep Blue Solutions, Ltd, All Rights Reserved.
5  *  Copyright (C) 2010 ST-Ericsson SA
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/init.h>
14 #include <linux/ioport.h>
15 #include <linux/device.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/slab.h>
19 #include <linux/delay.h>
20 #include <linux/err.h>
21 #include <linux/highmem.h>
22 #include <linux/log2.h>
23 #include <linux/mmc/host.h>
24 #include <linux/mmc/card.h>
25 #include <linux/amba/bus.h>
26 #include <linux/clk.h>
27 #include <linux/scatterlist.h>
28 #include <linux/gpio.h>
29 #include <linux/of_gpio.h>
30 #include <linux/regulator/consumer.h>
31 #include <linux/dmaengine.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/amba/mmci.h>
34 #include <linux/pm_runtime.h>
35 #include <linux/types.h>
36 #include <linux/pinctrl/consumer.h>
37 
38 #include <asm/div64.h>
39 #include <asm/io.h>
40 #include <asm/sizes.h>
41 
42 #include "mmci.h"
43 
44 #define DRIVER_NAME "mmci-pl18x"
45 
46 static unsigned int fmax = 515633;
47 
48 /**
49  * struct variant_data - MMCI variant-specific quirks
50  * @clkreg: default value for MCICLOCK register
51  * @clkreg_enable: enable value for MMCICLOCK register
52  * @datalength_bits: number of bits in the MMCIDATALENGTH register
53  * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
54  *	      is asserted (likewise for RX)
55  * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY
56  *		  is asserted (likewise for RX)
57  * @sdio: variant supports SDIO
58  * @st_clkdiv: true if using a ST-specific clock divider algorithm
59  * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register
60  * @pwrreg_powerup: power up value for MMCIPOWER register
61  * @signal_direction: input/out direction of bus signals can be indicated
62  */
63 struct variant_data {
64 	unsigned int		clkreg;
65 	unsigned int		clkreg_enable;
66 	unsigned int		datalength_bits;
67 	unsigned int		fifosize;
68 	unsigned int		fifohalfsize;
69 	bool			sdio;
70 	bool			st_clkdiv;
71 	bool			blksz_datactrl16;
72 	u32			pwrreg_powerup;
73 	bool			signal_direction;
74 };
75 
76 static struct variant_data variant_arm = {
77 	.fifosize		= 16 * 4,
78 	.fifohalfsize		= 8 * 4,
79 	.datalength_bits	= 16,
80 	.pwrreg_powerup		= MCI_PWR_UP,
81 };
82 
83 static struct variant_data variant_arm_extended_fifo = {
84 	.fifosize		= 128 * 4,
85 	.fifohalfsize		= 64 * 4,
86 	.datalength_bits	= 16,
87 	.pwrreg_powerup		= MCI_PWR_UP,
88 };
89 
90 static struct variant_data variant_u300 = {
91 	.fifosize		= 16 * 4,
92 	.fifohalfsize		= 8 * 4,
93 	.clkreg_enable		= MCI_ST_U300_HWFCEN,
94 	.datalength_bits	= 16,
95 	.sdio			= true,
96 	.pwrreg_powerup		= MCI_PWR_ON,
97 	.signal_direction	= true,
98 };
99 
100 static struct variant_data variant_nomadik = {
101 	.fifosize		= 16 * 4,
102 	.fifohalfsize		= 8 * 4,
103 	.clkreg			= MCI_CLK_ENABLE,
104 	.datalength_bits	= 24,
105 	.sdio			= true,
106 	.st_clkdiv		= true,
107 	.pwrreg_powerup		= MCI_PWR_ON,
108 	.signal_direction	= true,
109 };
110 
111 static struct variant_data variant_ux500 = {
112 	.fifosize		= 30 * 4,
113 	.fifohalfsize		= 8 * 4,
114 	.clkreg			= MCI_CLK_ENABLE,
115 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
116 	.datalength_bits	= 24,
117 	.sdio			= true,
118 	.st_clkdiv		= true,
119 	.pwrreg_powerup		= MCI_PWR_ON,
120 	.signal_direction	= true,
121 };
122 
123 static struct variant_data variant_ux500v2 = {
124 	.fifosize		= 30 * 4,
125 	.fifohalfsize		= 8 * 4,
126 	.clkreg			= MCI_CLK_ENABLE,
127 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
128 	.datalength_bits	= 24,
129 	.sdio			= true,
130 	.st_clkdiv		= true,
131 	.blksz_datactrl16	= true,
132 	.pwrreg_powerup		= MCI_PWR_ON,
133 	.signal_direction	= true,
134 };
135 
136 /*
137  * This must be called with host->lock held
138  */
139 static void mmci_write_clkreg(struct mmci_host *host, u32 clk)
140 {
141 	if (host->clk_reg != clk) {
142 		host->clk_reg = clk;
143 		writel(clk, host->base + MMCICLOCK);
144 	}
145 }
146 
147 /*
148  * This must be called with host->lock held
149  */
150 static void mmci_write_pwrreg(struct mmci_host *host, u32 pwr)
151 {
152 	if (host->pwr_reg != pwr) {
153 		host->pwr_reg = pwr;
154 		writel(pwr, host->base + MMCIPOWER);
155 	}
156 }
157 
158 /*
159  * This must be called with host->lock held
160  */
161 static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
162 {
163 	struct variant_data *variant = host->variant;
164 	u32 clk = variant->clkreg;
165 
166 	if (desired) {
167 		if (desired >= host->mclk) {
168 			clk = MCI_CLK_BYPASS;
169 			if (variant->st_clkdiv)
170 				clk |= MCI_ST_UX500_NEG_EDGE;
171 			host->cclk = host->mclk;
172 		} else if (variant->st_clkdiv) {
173 			/*
174 			 * DB8500 TRM says f = mclk / (clkdiv + 2)
175 			 * => clkdiv = (mclk / f) - 2
176 			 * Round the divider up so we don't exceed the max
177 			 * frequency
178 			 */
179 			clk = DIV_ROUND_UP(host->mclk, desired) - 2;
180 			if (clk >= 256)
181 				clk = 255;
182 			host->cclk = host->mclk / (clk + 2);
183 		} else {
184 			/*
185 			 * PL180 TRM says f = mclk / (2 * (clkdiv + 1))
186 			 * => clkdiv = mclk / (2 * f) - 1
187 			 */
188 			clk = host->mclk / (2 * desired) - 1;
189 			if (clk >= 256)
190 				clk = 255;
191 			host->cclk = host->mclk / (2 * (clk + 1));
192 		}
193 
194 		clk |= variant->clkreg_enable;
195 		clk |= MCI_CLK_ENABLE;
196 		/* This hasn't proven to be worthwhile */
197 		/* clk |= MCI_CLK_PWRSAVE; */
198 	}
199 
200 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
201 		clk |= MCI_4BIT_BUS;
202 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
203 		clk |= MCI_ST_8BIT_BUS;
204 
205 	mmci_write_clkreg(host, clk);
206 }
207 
208 static void
209 mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
210 {
211 	writel(0, host->base + MMCICOMMAND);
212 
213 	BUG_ON(host->data);
214 
215 	host->mrq = NULL;
216 	host->cmd = NULL;
217 
218 	mmc_request_done(host->mmc, mrq);
219 
220 	pm_runtime_mark_last_busy(mmc_dev(host->mmc));
221 	pm_runtime_put_autosuspend(mmc_dev(host->mmc));
222 }
223 
224 static void mmci_set_mask1(struct mmci_host *host, unsigned int mask)
225 {
226 	void __iomem *base = host->base;
227 
228 	if (host->singleirq) {
229 		unsigned int mask0 = readl(base + MMCIMASK0);
230 
231 		mask0 &= ~MCI_IRQ1MASK;
232 		mask0 |= mask;
233 
234 		writel(mask0, base + MMCIMASK0);
235 	}
236 
237 	writel(mask, base + MMCIMASK1);
238 }
239 
240 static void mmci_stop_data(struct mmci_host *host)
241 {
242 	writel(0, host->base + MMCIDATACTRL);
243 	mmci_set_mask1(host, 0);
244 	host->data = NULL;
245 }
246 
247 static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
248 {
249 	unsigned int flags = SG_MITER_ATOMIC;
250 
251 	if (data->flags & MMC_DATA_READ)
252 		flags |= SG_MITER_TO_SG;
253 	else
254 		flags |= SG_MITER_FROM_SG;
255 
256 	sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
257 }
258 
259 /*
260  * All the DMA operation mode stuff goes inside this ifdef.
261  * This assumes that you have a generic DMA device interface,
262  * no custom DMA interfaces are supported.
263  */
264 #ifdef CONFIG_DMA_ENGINE
265 static void mmci_dma_setup(struct mmci_host *host)
266 {
267 	struct mmci_platform_data *plat = host->plat;
268 	const char *rxname, *txname;
269 	dma_cap_mask_t mask;
270 
271 	if (!plat || !plat->dma_filter) {
272 		dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
273 		return;
274 	}
275 
276 	/* initialize pre request cookie */
277 	host->next_data.cookie = 1;
278 
279 	/* Try to acquire a generic DMA engine slave channel */
280 	dma_cap_zero(mask);
281 	dma_cap_set(DMA_SLAVE, mask);
282 
283 	/*
284 	 * If only an RX channel is specified, the driver will
285 	 * attempt to use it bidirectionally, however if it is
286 	 * is specified but cannot be located, DMA will be disabled.
287 	 */
288 	if (plat->dma_rx_param) {
289 		host->dma_rx_channel = dma_request_channel(mask,
290 							   plat->dma_filter,
291 							   plat->dma_rx_param);
292 		/* E.g if no DMA hardware is present */
293 		if (!host->dma_rx_channel)
294 			dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
295 	}
296 
297 	if (plat->dma_tx_param) {
298 		host->dma_tx_channel = dma_request_channel(mask,
299 							   plat->dma_filter,
300 							   plat->dma_tx_param);
301 		if (!host->dma_tx_channel)
302 			dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
303 	} else {
304 		host->dma_tx_channel = host->dma_rx_channel;
305 	}
306 
307 	if (host->dma_rx_channel)
308 		rxname = dma_chan_name(host->dma_rx_channel);
309 	else
310 		rxname = "none";
311 
312 	if (host->dma_tx_channel)
313 		txname = dma_chan_name(host->dma_tx_channel);
314 	else
315 		txname = "none";
316 
317 	dev_info(mmc_dev(host->mmc), "DMA channels RX %s, TX %s\n",
318 		 rxname, txname);
319 
320 	/*
321 	 * Limit the maximum segment size in any SG entry according to
322 	 * the parameters of the DMA engine device.
323 	 */
324 	if (host->dma_tx_channel) {
325 		struct device *dev = host->dma_tx_channel->device->dev;
326 		unsigned int max_seg_size = dma_get_max_seg_size(dev);
327 
328 		if (max_seg_size < host->mmc->max_seg_size)
329 			host->mmc->max_seg_size = max_seg_size;
330 	}
331 	if (host->dma_rx_channel) {
332 		struct device *dev = host->dma_rx_channel->device->dev;
333 		unsigned int max_seg_size = dma_get_max_seg_size(dev);
334 
335 		if (max_seg_size < host->mmc->max_seg_size)
336 			host->mmc->max_seg_size = max_seg_size;
337 	}
338 }
339 
340 /*
341  * This is used in or so inline it
342  * so it can be discarded.
343  */
344 static inline void mmci_dma_release(struct mmci_host *host)
345 {
346 	struct mmci_platform_data *plat = host->plat;
347 
348 	if (host->dma_rx_channel)
349 		dma_release_channel(host->dma_rx_channel);
350 	if (host->dma_tx_channel && plat->dma_tx_param)
351 		dma_release_channel(host->dma_tx_channel);
352 	host->dma_rx_channel = host->dma_tx_channel = NULL;
353 }
354 
355 static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
356 {
357 	struct dma_chan *chan = host->dma_current;
358 	enum dma_data_direction dir;
359 	u32 status;
360 	int i;
361 
362 	/* Wait up to 1ms for the DMA to complete */
363 	for (i = 0; ; i++) {
364 		status = readl(host->base + MMCISTATUS);
365 		if (!(status & MCI_RXDATAAVLBLMASK) || i >= 100)
366 			break;
367 		udelay(10);
368 	}
369 
370 	/*
371 	 * Check to see whether we still have some data left in the FIFO -
372 	 * this catches DMA controllers which are unable to monitor the
373 	 * DMALBREQ and DMALSREQ signals while allowing us to DMA to non-
374 	 * contiguous buffers.  On TX, we'll get a FIFO underrun error.
375 	 */
376 	if (status & MCI_RXDATAAVLBLMASK) {
377 		dmaengine_terminate_all(chan);
378 		if (!data->error)
379 			data->error = -EIO;
380 	}
381 
382 	if (data->flags & MMC_DATA_WRITE) {
383 		dir = DMA_TO_DEVICE;
384 	} else {
385 		dir = DMA_FROM_DEVICE;
386 	}
387 
388 	if (!data->host_cookie)
389 		dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
390 
391 	/*
392 	 * Use of DMA with scatter-gather is impossible.
393 	 * Give up with DMA and switch back to PIO mode.
394 	 */
395 	if (status & MCI_RXDATAAVLBLMASK) {
396 		dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
397 		mmci_dma_release(host);
398 	}
399 }
400 
401 static void mmci_dma_data_error(struct mmci_host *host)
402 {
403 	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
404 	dmaengine_terminate_all(host->dma_current);
405 }
406 
407 static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
408 			      struct mmci_host_next *next)
409 {
410 	struct variant_data *variant = host->variant;
411 	struct dma_slave_config conf = {
412 		.src_addr = host->phybase + MMCIFIFO,
413 		.dst_addr = host->phybase + MMCIFIFO,
414 		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
415 		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
416 		.src_maxburst = variant->fifohalfsize >> 2, /* # of words */
417 		.dst_maxburst = variant->fifohalfsize >> 2, /* # of words */
418 		.device_fc = false,
419 	};
420 	struct dma_chan *chan;
421 	struct dma_device *device;
422 	struct dma_async_tx_descriptor *desc;
423 	enum dma_data_direction buffer_dirn;
424 	int nr_sg;
425 
426 	/* Check if next job is already prepared */
427 	if (data->host_cookie && !next &&
428 	    host->dma_current && host->dma_desc_current)
429 		return 0;
430 
431 	if (!next) {
432 		host->dma_current = NULL;
433 		host->dma_desc_current = NULL;
434 	}
435 
436 	if (data->flags & MMC_DATA_READ) {
437 		conf.direction = DMA_DEV_TO_MEM;
438 		buffer_dirn = DMA_FROM_DEVICE;
439 		chan = host->dma_rx_channel;
440 	} else {
441 		conf.direction = DMA_MEM_TO_DEV;
442 		buffer_dirn = DMA_TO_DEVICE;
443 		chan = host->dma_tx_channel;
444 	}
445 
446 	/* If there's no DMA channel, fall back to PIO */
447 	if (!chan)
448 		return -EINVAL;
449 
450 	/* If less than or equal to the fifo size, don't bother with DMA */
451 	if (data->blksz * data->blocks <= variant->fifosize)
452 		return -EINVAL;
453 
454 	device = chan->device;
455 	nr_sg = dma_map_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
456 	if (nr_sg == 0)
457 		return -EINVAL;
458 
459 	dmaengine_slave_config(chan, &conf);
460 	desc = dmaengine_prep_slave_sg(chan, data->sg, nr_sg,
461 					    conf.direction, DMA_CTRL_ACK);
462 	if (!desc)
463 		goto unmap_exit;
464 
465 	if (next) {
466 		next->dma_chan = chan;
467 		next->dma_desc = desc;
468 	} else {
469 		host->dma_current = chan;
470 		host->dma_desc_current = desc;
471 	}
472 
473 	return 0;
474 
475  unmap_exit:
476 	if (!next)
477 		dmaengine_terminate_all(chan);
478 	dma_unmap_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
479 	return -ENOMEM;
480 }
481 
482 static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
483 {
484 	int ret;
485 	struct mmc_data *data = host->data;
486 
487 	ret = mmci_dma_prep_data(host, host->data, NULL);
488 	if (ret)
489 		return ret;
490 
491 	/* Okay, go for it. */
492 	dev_vdbg(mmc_dev(host->mmc),
493 		 "Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
494 		 data->sg_len, data->blksz, data->blocks, data->flags);
495 	dmaengine_submit(host->dma_desc_current);
496 	dma_async_issue_pending(host->dma_current);
497 
498 	datactrl |= MCI_DPSM_DMAENABLE;
499 
500 	/* Trigger the DMA transfer */
501 	writel(datactrl, host->base + MMCIDATACTRL);
502 
503 	/*
504 	 * Let the MMCI say when the data is ended and it's time
505 	 * to fire next DMA request. When that happens, MMCI will
506 	 * call mmci_data_end()
507 	 */
508 	writel(readl(host->base + MMCIMASK0) | MCI_DATAENDMASK,
509 	       host->base + MMCIMASK0);
510 	return 0;
511 }
512 
513 static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
514 {
515 	struct mmci_host_next *next = &host->next_data;
516 
517 	if (data->host_cookie && data->host_cookie != next->cookie) {
518 		pr_warning("[%s] invalid cookie: data->host_cookie %d"
519 		       " host->next_data.cookie %d\n",
520 		       __func__, data->host_cookie, host->next_data.cookie);
521 		data->host_cookie = 0;
522 	}
523 
524 	if (!data->host_cookie)
525 		return;
526 
527 	host->dma_desc_current = next->dma_desc;
528 	host->dma_current = next->dma_chan;
529 
530 	next->dma_desc = NULL;
531 	next->dma_chan = NULL;
532 }
533 
534 static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq,
535 			     bool is_first_req)
536 {
537 	struct mmci_host *host = mmc_priv(mmc);
538 	struct mmc_data *data = mrq->data;
539 	struct mmci_host_next *nd = &host->next_data;
540 
541 	if (!data)
542 		return;
543 
544 	if (data->host_cookie) {
545 		data->host_cookie = 0;
546 		return;
547 	}
548 
549 	/* if config for dma */
550 	if (((data->flags & MMC_DATA_WRITE) && host->dma_tx_channel) ||
551 	    ((data->flags & MMC_DATA_READ) && host->dma_rx_channel)) {
552 		if (mmci_dma_prep_data(host, data, nd))
553 			data->host_cookie = 0;
554 		else
555 			data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
556 	}
557 }
558 
559 static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
560 			      int err)
561 {
562 	struct mmci_host *host = mmc_priv(mmc);
563 	struct mmc_data *data = mrq->data;
564 	struct dma_chan *chan;
565 	enum dma_data_direction dir;
566 
567 	if (!data)
568 		return;
569 
570 	if (data->flags & MMC_DATA_READ) {
571 		dir = DMA_FROM_DEVICE;
572 		chan = host->dma_rx_channel;
573 	} else {
574 		dir = DMA_TO_DEVICE;
575 		chan = host->dma_tx_channel;
576 	}
577 
578 
579 	/* if config for dma */
580 	if (chan) {
581 		if (err)
582 			dmaengine_terminate_all(chan);
583 		if (data->host_cookie)
584 			dma_unmap_sg(mmc_dev(host->mmc), data->sg,
585 				     data->sg_len, dir);
586 		mrq->data->host_cookie = 0;
587 	}
588 }
589 
590 #else
591 /* Blank functions if the DMA engine is not available */
592 static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
593 {
594 }
595 static inline void mmci_dma_setup(struct mmci_host *host)
596 {
597 }
598 
599 static inline void mmci_dma_release(struct mmci_host *host)
600 {
601 }
602 
603 static inline void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
604 {
605 }
606 
607 static inline void mmci_dma_data_error(struct mmci_host *host)
608 {
609 }
610 
611 static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
612 {
613 	return -ENOSYS;
614 }
615 
616 #define mmci_pre_request NULL
617 #define mmci_post_request NULL
618 
619 #endif
620 
621 static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
622 {
623 	struct variant_data *variant = host->variant;
624 	unsigned int datactrl, timeout, irqmask;
625 	unsigned long long clks;
626 	void __iomem *base;
627 	int blksz_bits;
628 
629 	dev_dbg(mmc_dev(host->mmc), "blksz %04x blks %04x flags %08x\n",
630 		data->blksz, data->blocks, data->flags);
631 
632 	host->data = data;
633 	host->size = data->blksz * data->blocks;
634 	data->bytes_xfered = 0;
635 
636 	clks = (unsigned long long)data->timeout_ns * host->cclk;
637 	do_div(clks, 1000000000UL);
638 
639 	timeout = data->timeout_clks + (unsigned int)clks;
640 
641 	base = host->base;
642 	writel(timeout, base + MMCIDATATIMER);
643 	writel(host->size, base + MMCIDATALENGTH);
644 
645 	blksz_bits = ffs(data->blksz) - 1;
646 	BUG_ON(1 << blksz_bits != data->blksz);
647 
648 	if (variant->blksz_datactrl16)
649 		datactrl = MCI_DPSM_ENABLE | (data->blksz << 16);
650 	else
651 		datactrl = MCI_DPSM_ENABLE | blksz_bits << 4;
652 
653 	if (data->flags & MMC_DATA_READ)
654 		datactrl |= MCI_DPSM_DIRECTION;
655 
656 	/* The ST Micro variants has a special bit to enable SDIO */
657 	if (variant->sdio && host->mmc->card)
658 		if (mmc_card_sdio(host->mmc->card)) {
659 			/*
660 			 * The ST Micro variants has a special bit
661 			 * to enable SDIO.
662 			 */
663 			u32 clk;
664 
665 			datactrl |= MCI_ST_DPSM_SDIOEN;
666 
667 			/*
668 			 * The ST Micro variant for SDIO small write transfers
669 			 * needs to have clock H/W flow control disabled,
670 			 * otherwise the transfer will not start. The threshold
671 			 * depends on the rate of MCLK.
672 			 */
673 			if (data->flags & MMC_DATA_WRITE &&
674 			    (host->size < 8 ||
675 			     (host->size <= 8 && host->mclk > 50000000)))
676 				clk = host->clk_reg & ~variant->clkreg_enable;
677 			else
678 				clk = host->clk_reg | variant->clkreg_enable;
679 
680 			mmci_write_clkreg(host, clk);
681 		}
682 
683 	/*
684 	 * Attempt to use DMA operation mode, if this
685 	 * should fail, fall back to PIO mode
686 	 */
687 	if (!mmci_dma_start_data(host, datactrl))
688 		return;
689 
690 	/* IRQ mode, map the SG list for CPU reading/writing */
691 	mmci_init_sg(host, data);
692 
693 	if (data->flags & MMC_DATA_READ) {
694 		irqmask = MCI_RXFIFOHALFFULLMASK;
695 
696 		/*
697 		 * If we have less than the fifo 'half-full' threshold to
698 		 * transfer, trigger a PIO interrupt as soon as any data
699 		 * is available.
700 		 */
701 		if (host->size < variant->fifohalfsize)
702 			irqmask |= MCI_RXDATAAVLBLMASK;
703 	} else {
704 		/*
705 		 * We don't actually need to include "FIFO empty" here
706 		 * since its implicit in "FIFO half empty".
707 		 */
708 		irqmask = MCI_TXFIFOHALFEMPTYMASK;
709 	}
710 
711 	writel(datactrl, base + MMCIDATACTRL);
712 	writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
713 	mmci_set_mask1(host, irqmask);
714 }
715 
716 static void
717 mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
718 {
719 	void __iomem *base = host->base;
720 
721 	dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
722 	    cmd->opcode, cmd->arg, cmd->flags);
723 
724 	if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
725 		writel(0, base + MMCICOMMAND);
726 		udelay(1);
727 	}
728 
729 	c |= cmd->opcode | MCI_CPSM_ENABLE;
730 	if (cmd->flags & MMC_RSP_PRESENT) {
731 		if (cmd->flags & MMC_RSP_136)
732 			c |= MCI_CPSM_LONGRSP;
733 		c |= MCI_CPSM_RESPONSE;
734 	}
735 	if (/*interrupt*/0)
736 		c |= MCI_CPSM_INTERRUPT;
737 
738 	host->cmd = cmd;
739 
740 	writel(cmd->arg, base + MMCIARGUMENT);
741 	writel(c, base + MMCICOMMAND);
742 }
743 
744 static void
745 mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
746 	      unsigned int status)
747 {
748 	/* First check for errors */
749 	if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_STARTBITERR|
750 		      MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
751 		u32 remain, success;
752 
753 		/* Terminate the DMA transfer */
754 		if (dma_inprogress(host))
755 			mmci_dma_data_error(host);
756 
757 		/*
758 		 * Calculate how far we are into the transfer.  Note that
759 		 * the data counter gives the number of bytes transferred
760 		 * on the MMC bus, not on the host side.  On reads, this
761 		 * can be as much as a FIFO-worth of data ahead.  This
762 		 * matters for FIFO overruns only.
763 		 */
764 		remain = readl(host->base + MMCIDATACNT);
765 		success = data->blksz * data->blocks - remain;
766 
767 		dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ, status 0x%08x at 0x%08x\n",
768 			status, success);
769 		if (status & MCI_DATACRCFAIL) {
770 			/* Last block was not successful */
771 			success -= 1;
772 			data->error = -EILSEQ;
773 		} else if (status & MCI_DATATIMEOUT) {
774 			data->error = -ETIMEDOUT;
775 		} else if (status & MCI_STARTBITERR) {
776 			data->error = -ECOMM;
777 		} else if (status & MCI_TXUNDERRUN) {
778 			data->error = -EIO;
779 		} else if (status & MCI_RXOVERRUN) {
780 			if (success > host->variant->fifosize)
781 				success -= host->variant->fifosize;
782 			else
783 				success = 0;
784 			data->error = -EIO;
785 		}
786 		data->bytes_xfered = round_down(success, data->blksz);
787 	}
788 
789 	if (status & MCI_DATABLOCKEND)
790 		dev_err(mmc_dev(host->mmc), "stray MCI_DATABLOCKEND interrupt\n");
791 
792 	if (status & MCI_DATAEND || data->error) {
793 		if (dma_inprogress(host))
794 			mmci_dma_unmap(host, data);
795 		mmci_stop_data(host);
796 
797 		if (!data->error)
798 			/* The error clause is handled above, success! */
799 			data->bytes_xfered = data->blksz * data->blocks;
800 
801 		if (!data->stop) {
802 			mmci_request_end(host, data->mrq);
803 		} else {
804 			mmci_start_command(host, data->stop, 0);
805 		}
806 	}
807 }
808 
809 static void
810 mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
811 	     unsigned int status)
812 {
813 	void __iomem *base = host->base;
814 
815 	host->cmd = NULL;
816 
817 	if (status & MCI_CMDTIMEOUT) {
818 		cmd->error = -ETIMEDOUT;
819 	} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
820 		cmd->error = -EILSEQ;
821 	} else {
822 		cmd->resp[0] = readl(base + MMCIRESPONSE0);
823 		cmd->resp[1] = readl(base + MMCIRESPONSE1);
824 		cmd->resp[2] = readl(base + MMCIRESPONSE2);
825 		cmd->resp[3] = readl(base + MMCIRESPONSE3);
826 	}
827 
828 	if (!cmd->data || cmd->error) {
829 		if (host->data) {
830 			/* Terminate the DMA transfer */
831 			if (dma_inprogress(host))
832 				mmci_dma_data_error(host);
833 			mmci_stop_data(host);
834 		}
835 		mmci_request_end(host, cmd->mrq);
836 	} else if (!(cmd->data->flags & MMC_DATA_READ)) {
837 		mmci_start_data(host, cmd->data);
838 	}
839 }
840 
841 static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain)
842 {
843 	void __iomem *base = host->base;
844 	char *ptr = buffer;
845 	u32 status;
846 	int host_remain = host->size;
847 
848 	do {
849 		int count = host_remain - (readl(base + MMCIFIFOCNT) << 2);
850 
851 		if (count > remain)
852 			count = remain;
853 
854 		if (count <= 0)
855 			break;
856 
857 		/*
858 		 * SDIO especially may want to send something that is
859 		 * not divisible by 4 (as opposed to card sectors
860 		 * etc). Therefore make sure to always read the last bytes
861 		 * while only doing full 32-bit reads towards the FIFO.
862 		 */
863 		if (unlikely(count & 0x3)) {
864 			if (count < 4) {
865 				unsigned char buf[4];
866 				ioread32_rep(base + MMCIFIFO, buf, 1);
867 				memcpy(ptr, buf, count);
868 			} else {
869 				ioread32_rep(base + MMCIFIFO, ptr, count >> 2);
870 				count &= ~0x3;
871 			}
872 		} else {
873 			ioread32_rep(base + MMCIFIFO, ptr, count >> 2);
874 		}
875 
876 		ptr += count;
877 		remain -= count;
878 		host_remain -= count;
879 
880 		if (remain == 0)
881 			break;
882 
883 		status = readl(base + MMCISTATUS);
884 	} while (status & MCI_RXDATAAVLBL);
885 
886 	return ptr - buffer;
887 }
888 
889 static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int remain, u32 status)
890 {
891 	struct variant_data *variant = host->variant;
892 	void __iomem *base = host->base;
893 	char *ptr = buffer;
894 
895 	do {
896 		unsigned int count, maxcnt;
897 
898 		maxcnt = status & MCI_TXFIFOEMPTY ?
899 			 variant->fifosize : variant->fifohalfsize;
900 		count = min(remain, maxcnt);
901 
902 		/*
903 		 * SDIO especially may want to send something that is
904 		 * not divisible by 4 (as opposed to card sectors
905 		 * etc), and the FIFO only accept full 32-bit writes.
906 		 * So compensate by adding +3 on the count, a single
907 		 * byte become a 32bit write, 7 bytes will be two
908 		 * 32bit writes etc.
909 		 */
910 		iowrite32_rep(base + MMCIFIFO, ptr, (count + 3) >> 2);
911 
912 		ptr += count;
913 		remain -= count;
914 
915 		if (remain == 0)
916 			break;
917 
918 		status = readl(base + MMCISTATUS);
919 	} while (status & MCI_TXFIFOHALFEMPTY);
920 
921 	return ptr - buffer;
922 }
923 
924 /*
925  * PIO data transfer IRQ handler.
926  */
927 static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
928 {
929 	struct mmci_host *host = dev_id;
930 	struct sg_mapping_iter *sg_miter = &host->sg_miter;
931 	struct variant_data *variant = host->variant;
932 	void __iomem *base = host->base;
933 	unsigned long flags;
934 	u32 status;
935 
936 	status = readl(base + MMCISTATUS);
937 
938 	dev_dbg(mmc_dev(host->mmc), "irq1 (pio) %08x\n", status);
939 
940 	local_irq_save(flags);
941 
942 	do {
943 		unsigned int remain, len;
944 		char *buffer;
945 
946 		/*
947 		 * For write, we only need to test the half-empty flag
948 		 * here - if the FIFO is completely empty, then by
949 		 * definition it is more than half empty.
950 		 *
951 		 * For read, check for data available.
952 		 */
953 		if (!(status & (MCI_TXFIFOHALFEMPTY|MCI_RXDATAAVLBL)))
954 			break;
955 
956 		if (!sg_miter_next(sg_miter))
957 			break;
958 
959 		buffer = sg_miter->addr;
960 		remain = sg_miter->length;
961 
962 		len = 0;
963 		if (status & MCI_RXACTIVE)
964 			len = mmci_pio_read(host, buffer, remain);
965 		if (status & MCI_TXACTIVE)
966 			len = mmci_pio_write(host, buffer, remain, status);
967 
968 		sg_miter->consumed = len;
969 
970 		host->size -= len;
971 		remain -= len;
972 
973 		if (remain)
974 			break;
975 
976 		status = readl(base + MMCISTATUS);
977 	} while (1);
978 
979 	sg_miter_stop(sg_miter);
980 
981 	local_irq_restore(flags);
982 
983 	/*
984 	 * If we have less than the fifo 'half-full' threshold to transfer,
985 	 * trigger a PIO interrupt as soon as any data is available.
986 	 */
987 	if (status & MCI_RXACTIVE && host->size < variant->fifohalfsize)
988 		mmci_set_mask1(host, MCI_RXDATAAVLBLMASK);
989 
990 	/*
991 	 * If we run out of data, disable the data IRQs; this
992 	 * prevents a race where the FIFO becomes empty before
993 	 * the chip itself has disabled the data path, and
994 	 * stops us racing with our data end IRQ.
995 	 */
996 	if (host->size == 0) {
997 		mmci_set_mask1(host, 0);
998 		writel(readl(base + MMCIMASK0) | MCI_DATAENDMASK, base + MMCIMASK0);
999 	}
1000 
1001 	return IRQ_HANDLED;
1002 }
1003 
1004 /*
1005  * Handle completion of command and data transfers.
1006  */
1007 static irqreturn_t mmci_irq(int irq, void *dev_id)
1008 {
1009 	struct mmci_host *host = dev_id;
1010 	u32 status;
1011 	int ret = 0;
1012 
1013 	spin_lock(&host->lock);
1014 
1015 	do {
1016 		struct mmc_command *cmd;
1017 		struct mmc_data *data;
1018 
1019 		status = readl(host->base + MMCISTATUS);
1020 
1021 		if (host->singleirq) {
1022 			if (status & readl(host->base + MMCIMASK1))
1023 				mmci_pio_irq(irq, dev_id);
1024 
1025 			status &= ~MCI_IRQ1MASK;
1026 		}
1027 
1028 		status &= readl(host->base + MMCIMASK0);
1029 		writel(status, host->base + MMCICLEAR);
1030 
1031 		dev_dbg(mmc_dev(host->mmc), "irq0 (data+cmd) %08x\n", status);
1032 
1033 		data = host->data;
1034 		if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_STARTBITERR|
1035 			      MCI_TXUNDERRUN|MCI_RXOVERRUN|MCI_DATAEND|
1036 			      MCI_DATABLOCKEND) && data)
1037 			mmci_data_irq(host, data, status);
1038 
1039 		cmd = host->cmd;
1040 		if (status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND) && cmd)
1041 			mmci_cmd_irq(host, cmd, status);
1042 
1043 		ret = 1;
1044 	} while (status);
1045 
1046 	spin_unlock(&host->lock);
1047 
1048 	return IRQ_RETVAL(ret);
1049 }
1050 
1051 static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
1052 {
1053 	struct mmci_host *host = mmc_priv(mmc);
1054 	unsigned long flags;
1055 
1056 	WARN_ON(host->mrq != NULL);
1057 
1058 	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
1059 		dev_err(mmc_dev(mmc), "unsupported block size (%d bytes)\n",
1060 			mrq->data->blksz);
1061 		mrq->cmd->error = -EINVAL;
1062 		mmc_request_done(mmc, mrq);
1063 		return;
1064 	}
1065 
1066 	pm_runtime_get_sync(mmc_dev(mmc));
1067 
1068 	spin_lock_irqsave(&host->lock, flags);
1069 
1070 	host->mrq = mrq;
1071 
1072 	if (mrq->data)
1073 		mmci_get_next_data(host, mrq->data);
1074 
1075 	if (mrq->data && mrq->data->flags & MMC_DATA_READ)
1076 		mmci_start_data(host, mrq->data);
1077 
1078 	mmci_start_command(host, mrq->cmd, 0);
1079 
1080 	spin_unlock_irqrestore(&host->lock, flags);
1081 }
1082 
1083 static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1084 {
1085 	struct mmci_host *host = mmc_priv(mmc);
1086 	struct variant_data *variant = host->variant;
1087 	u32 pwr = 0;
1088 	unsigned long flags;
1089 	int ret;
1090 
1091 	pm_runtime_get_sync(mmc_dev(mmc));
1092 
1093 	if (host->plat->ios_handler &&
1094 		host->plat->ios_handler(mmc_dev(mmc), ios))
1095 			dev_err(mmc_dev(mmc), "platform ios_handler failed\n");
1096 
1097 	switch (ios->power_mode) {
1098 	case MMC_POWER_OFF:
1099 		if (host->vcc)
1100 			ret = mmc_regulator_set_ocr(mmc, host->vcc, 0);
1101 		break;
1102 	case MMC_POWER_UP:
1103 		if (host->vcc) {
1104 			ret = mmc_regulator_set_ocr(mmc, host->vcc, ios->vdd);
1105 			if (ret) {
1106 				dev_err(mmc_dev(mmc), "unable to set OCR\n");
1107 				/*
1108 				 * The .set_ios() function in the mmc_host_ops
1109 				 * struct return void, and failing to set the
1110 				 * power should be rare so we print an error
1111 				 * and return here.
1112 				 */
1113 				goto out;
1114 			}
1115 		}
1116 		/*
1117 		 * The ST Micro variant doesn't have the PL180s MCI_PWR_UP
1118 		 * and instead uses MCI_PWR_ON so apply whatever value is
1119 		 * configured in the variant data.
1120 		 */
1121 		pwr |= variant->pwrreg_powerup;
1122 
1123 		break;
1124 	case MMC_POWER_ON:
1125 		pwr |= MCI_PWR_ON;
1126 		break;
1127 	}
1128 
1129 	if (variant->signal_direction && ios->power_mode != MMC_POWER_OFF) {
1130 		/*
1131 		 * The ST Micro variant has some additional bits
1132 		 * indicating signal direction for the signals in
1133 		 * the SD/MMC bus and feedback-clock usage.
1134 		 */
1135 		pwr |= host->plat->sigdir;
1136 
1137 		if (ios->bus_width == MMC_BUS_WIDTH_4)
1138 			pwr &= ~MCI_ST_DATA74DIREN;
1139 		else if (ios->bus_width == MMC_BUS_WIDTH_1)
1140 			pwr &= (~MCI_ST_DATA74DIREN &
1141 				~MCI_ST_DATA31DIREN &
1142 				~MCI_ST_DATA2DIREN);
1143 	}
1144 
1145 	if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
1146 		if (host->hw_designer != AMBA_VENDOR_ST)
1147 			pwr |= MCI_ROD;
1148 		else {
1149 			/*
1150 			 * The ST Micro variant use the ROD bit for something
1151 			 * else and only has OD (Open Drain).
1152 			 */
1153 			pwr |= MCI_OD;
1154 		}
1155 	}
1156 
1157 	spin_lock_irqsave(&host->lock, flags);
1158 
1159 	mmci_set_clkreg(host, ios->clock);
1160 	mmci_write_pwrreg(host, pwr);
1161 
1162 	spin_unlock_irqrestore(&host->lock, flags);
1163 
1164  out:
1165 	pm_runtime_mark_last_busy(mmc_dev(mmc));
1166 	pm_runtime_put_autosuspend(mmc_dev(mmc));
1167 }
1168 
1169 static int mmci_get_ro(struct mmc_host *mmc)
1170 {
1171 	struct mmci_host *host = mmc_priv(mmc);
1172 
1173 	if (host->gpio_wp == -ENOSYS)
1174 		return -ENOSYS;
1175 
1176 	return gpio_get_value_cansleep(host->gpio_wp);
1177 }
1178 
1179 static int mmci_get_cd(struct mmc_host *mmc)
1180 {
1181 	struct mmci_host *host = mmc_priv(mmc);
1182 	struct mmci_platform_data *plat = host->plat;
1183 	unsigned int status;
1184 
1185 	if (host->gpio_cd == -ENOSYS) {
1186 		if (!plat->status)
1187 			return 1; /* Assume always present */
1188 
1189 		status = plat->status(mmc_dev(host->mmc));
1190 	} else
1191 		status = !!gpio_get_value_cansleep(host->gpio_cd)
1192 			^ plat->cd_invert;
1193 
1194 	/*
1195 	 * Use positive logic throughout - status is zero for no card,
1196 	 * non-zero for card inserted.
1197 	 */
1198 	return status;
1199 }
1200 
1201 static irqreturn_t mmci_cd_irq(int irq, void *dev_id)
1202 {
1203 	struct mmci_host *host = dev_id;
1204 
1205 	mmc_detect_change(host->mmc, msecs_to_jiffies(500));
1206 
1207 	return IRQ_HANDLED;
1208 }
1209 
1210 static const struct mmc_host_ops mmci_ops = {
1211 	.request	= mmci_request,
1212 	.pre_req	= mmci_pre_request,
1213 	.post_req	= mmci_post_request,
1214 	.set_ios	= mmci_set_ios,
1215 	.get_ro		= mmci_get_ro,
1216 	.get_cd		= mmci_get_cd,
1217 };
1218 
1219 #ifdef CONFIG_OF
1220 static void mmci_dt_populate_generic_pdata(struct device_node *np,
1221 					struct mmci_platform_data *pdata)
1222 {
1223 	int bus_width = 0;
1224 
1225 	pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
1226 	pdata->gpio_cd = of_get_named_gpio(np, "cd-gpios", 0);
1227 
1228 	if (of_get_property(np, "cd-inverted", NULL))
1229 		pdata->cd_invert = true;
1230 	else
1231 		pdata->cd_invert = false;
1232 
1233 	of_property_read_u32(np, "max-frequency", &pdata->f_max);
1234 	if (!pdata->f_max)
1235 		pr_warn("%s has no 'max-frequency' property\n", np->full_name);
1236 
1237 	if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
1238 		pdata->capabilities |= MMC_CAP_MMC_HIGHSPEED;
1239 	if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
1240 		pdata->capabilities |= MMC_CAP_SD_HIGHSPEED;
1241 
1242 	of_property_read_u32(np, "bus-width", &bus_width);
1243 	switch (bus_width) {
1244 	case 0 :
1245 		/* No bus-width supplied. */
1246 		break;
1247 	case 4 :
1248 		pdata->capabilities |= MMC_CAP_4_BIT_DATA;
1249 		break;
1250 	case 8 :
1251 		pdata->capabilities |= MMC_CAP_8_BIT_DATA;
1252 		break;
1253 	default :
1254 		pr_warn("%s: Unsupported bus width\n", np->full_name);
1255 	}
1256 }
1257 #else
1258 static void mmci_dt_populate_generic_pdata(struct device_node *np,
1259 					struct mmci_platform_data *pdata)
1260 {
1261 	return;
1262 }
1263 #endif
1264 
1265 static int mmci_probe(struct amba_device *dev,
1266 	const struct amba_id *id)
1267 {
1268 	struct mmci_platform_data *plat = dev->dev.platform_data;
1269 	struct device_node *np = dev->dev.of_node;
1270 	struct variant_data *variant = id->data;
1271 	struct mmci_host *host;
1272 	struct mmc_host *mmc;
1273 	int ret;
1274 
1275 	/* Must have platform data or Device Tree. */
1276 	if (!plat && !np) {
1277 		dev_err(&dev->dev, "No plat data or DT found\n");
1278 		return -EINVAL;
1279 	}
1280 
1281 	if (!plat) {
1282 		plat = devm_kzalloc(&dev->dev, sizeof(*plat), GFP_KERNEL);
1283 		if (!plat)
1284 			return -ENOMEM;
1285 	}
1286 
1287 	if (np)
1288 		mmci_dt_populate_generic_pdata(np, plat);
1289 
1290 	ret = amba_request_regions(dev, DRIVER_NAME);
1291 	if (ret)
1292 		goto out;
1293 
1294 	mmc = mmc_alloc_host(sizeof(struct mmci_host), &dev->dev);
1295 	if (!mmc) {
1296 		ret = -ENOMEM;
1297 		goto rel_regions;
1298 	}
1299 
1300 	host = mmc_priv(mmc);
1301 	host->mmc = mmc;
1302 
1303 	host->gpio_wp = -ENOSYS;
1304 	host->gpio_cd = -ENOSYS;
1305 	host->gpio_cd_irq = -1;
1306 
1307 	host->hw_designer = amba_manf(dev);
1308 	host->hw_revision = amba_rev(dev);
1309 	dev_dbg(mmc_dev(mmc), "designer ID = 0x%02x\n", host->hw_designer);
1310 	dev_dbg(mmc_dev(mmc), "revision = 0x%01x\n", host->hw_revision);
1311 
1312 	host->clk = clk_get(&dev->dev, NULL);
1313 	if (IS_ERR(host->clk)) {
1314 		ret = PTR_ERR(host->clk);
1315 		host->clk = NULL;
1316 		goto host_free;
1317 	}
1318 
1319 	ret = clk_prepare_enable(host->clk);
1320 	if (ret)
1321 		goto clk_free;
1322 
1323 	host->plat = plat;
1324 	host->variant = variant;
1325 	host->mclk = clk_get_rate(host->clk);
1326 	/*
1327 	 * According to the spec, mclk is max 100 MHz,
1328 	 * so we try to adjust the clock down to this,
1329 	 * (if possible).
1330 	 */
1331 	if (host->mclk > 100000000) {
1332 		ret = clk_set_rate(host->clk, 100000000);
1333 		if (ret < 0)
1334 			goto clk_disable;
1335 		host->mclk = clk_get_rate(host->clk);
1336 		dev_dbg(mmc_dev(mmc), "eventual mclk rate: %u Hz\n",
1337 			host->mclk);
1338 	}
1339 	host->phybase = dev->res.start;
1340 	host->base = ioremap(dev->res.start, resource_size(&dev->res));
1341 	if (!host->base) {
1342 		ret = -ENOMEM;
1343 		goto clk_disable;
1344 	}
1345 
1346 	mmc->ops = &mmci_ops;
1347 	/*
1348 	 * The ARM and ST versions of the block have slightly different
1349 	 * clock divider equations which means that the minimum divider
1350 	 * differs too.
1351 	 */
1352 	if (variant->st_clkdiv)
1353 		mmc->f_min = DIV_ROUND_UP(host->mclk, 257);
1354 	else
1355 		mmc->f_min = DIV_ROUND_UP(host->mclk, 512);
1356 	/*
1357 	 * If the platform data supplies a maximum operating
1358 	 * frequency, this takes precedence. Else, we fall back
1359 	 * to using the module parameter, which has a (low)
1360 	 * default value in case it is not specified. Either
1361 	 * value must not exceed the clock rate into the block,
1362 	 * of course.
1363 	 */
1364 	if (plat->f_max)
1365 		mmc->f_max = min(host->mclk, plat->f_max);
1366 	else
1367 		mmc->f_max = min(host->mclk, fmax);
1368 	dev_dbg(mmc_dev(mmc), "clocking block at %u Hz\n", mmc->f_max);
1369 
1370 	host->pinctrl = devm_pinctrl_get(&dev->dev);
1371 	if (IS_ERR(host->pinctrl)) {
1372 		ret = PTR_ERR(host->pinctrl);
1373 		goto clk_disable;
1374 	}
1375 
1376 	host->pins_default = pinctrl_lookup_state(host->pinctrl,
1377 			PINCTRL_STATE_DEFAULT);
1378 
1379 	/* enable pins to be muxed in and configured */
1380 	if (!IS_ERR(host->pins_default)) {
1381 		ret = pinctrl_select_state(host->pinctrl, host->pins_default);
1382 		if (ret)
1383 			dev_warn(&dev->dev, "could not set default pins\n");
1384 	} else
1385 		dev_warn(&dev->dev, "could not get default pinstate\n");
1386 
1387 #ifdef CONFIG_REGULATOR
1388 	/* If we're using the regulator framework, try to fetch a regulator */
1389 	host->vcc = regulator_get(&dev->dev, "vmmc");
1390 	if (IS_ERR(host->vcc))
1391 		host->vcc = NULL;
1392 	else {
1393 		int mask = mmc_regulator_get_ocrmask(host->vcc);
1394 
1395 		if (mask < 0)
1396 			dev_err(&dev->dev, "error getting OCR mask (%d)\n",
1397 				mask);
1398 		else {
1399 			host->mmc->ocr_avail = (u32) mask;
1400 			if (plat->ocr_mask)
1401 				dev_warn(&dev->dev,
1402 				 "Provided ocr_mask/setpower will not be used "
1403 				 "(using regulator instead)\n");
1404 		}
1405 	}
1406 #endif
1407 	/* Fall back to platform data if no regulator is found */
1408 	if (host->vcc == NULL)
1409 		mmc->ocr_avail = plat->ocr_mask;
1410 	mmc->caps = plat->capabilities;
1411 	mmc->caps2 = plat->capabilities2;
1412 
1413 	/*
1414 	 * We can do SGIO
1415 	 */
1416 	mmc->max_segs = NR_SG;
1417 
1418 	/*
1419 	 * Since only a certain number of bits are valid in the data length
1420 	 * register, we must ensure that we don't exceed 2^num-1 bytes in a
1421 	 * single request.
1422 	 */
1423 	mmc->max_req_size = (1 << variant->datalength_bits) - 1;
1424 
1425 	/*
1426 	 * Set the maximum segment size.  Since we aren't doing DMA
1427 	 * (yet) we are only limited by the data length register.
1428 	 */
1429 	mmc->max_seg_size = mmc->max_req_size;
1430 
1431 	/*
1432 	 * Block size can be up to 2048 bytes, but must be a power of two.
1433 	 */
1434 	mmc->max_blk_size = 1 << 11;
1435 
1436 	/*
1437 	 * Limit the number of blocks transferred so that we don't overflow
1438 	 * the maximum request size.
1439 	 */
1440 	mmc->max_blk_count = mmc->max_req_size >> 11;
1441 
1442 	spin_lock_init(&host->lock);
1443 
1444 	writel(0, host->base + MMCIMASK0);
1445 	writel(0, host->base + MMCIMASK1);
1446 	writel(0xfff, host->base + MMCICLEAR);
1447 
1448 	if (plat->gpio_cd == -EPROBE_DEFER) {
1449 		ret = -EPROBE_DEFER;
1450 		goto err_gpio_cd;
1451 	}
1452 	if (gpio_is_valid(plat->gpio_cd)) {
1453 		ret = gpio_request(plat->gpio_cd, DRIVER_NAME " (cd)");
1454 		if (ret == 0)
1455 			ret = gpio_direction_input(plat->gpio_cd);
1456 		if (ret == 0)
1457 			host->gpio_cd = plat->gpio_cd;
1458 		else if (ret != -ENOSYS)
1459 			goto err_gpio_cd;
1460 
1461 		/*
1462 		 * A gpio pin that will detect cards when inserted and removed
1463 		 * will most likely want to trigger on the edges if it is
1464 		 * 0 when ejected and 1 when inserted (or mutatis mutandis
1465 		 * for the inverted case) so we request triggers on both
1466 		 * edges.
1467 		 */
1468 		ret = request_any_context_irq(gpio_to_irq(plat->gpio_cd),
1469 				mmci_cd_irq,
1470 				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
1471 				DRIVER_NAME " (cd)", host);
1472 		if (ret >= 0)
1473 			host->gpio_cd_irq = gpio_to_irq(plat->gpio_cd);
1474 	}
1475 	if (plat->gpio_wp == -EPROBE_DEFER) {
1476 		ret = -EPROBE_DEFER;
1477 		goto err_gpio_wp;
1478 	}
1479 	if (gpio_is_valid(plat->gpio_wp)) {
1480 		ret = gpio_request(plat->gpio_wp, DRIVER_NAME " (wp)");
1481 		if (ret == 0)
1482 			ret = gpio_direction_input(plat->gpio_wp);
1483 		if (ret == 0)
1484 			host->gpio_wp = plat->gpio_wp;
1485 		else if (ret != -ENOSYS)
1486 			goto err_gpio_wp;
1487 	}
1488 
1489 	if ((host->plat->status || host->gpio_cd != -ENOSYS)
1490 	    && host->gpio_cd_irq < 0)
1491 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1492 
1493 	ret = request_irq(dev->irq[0], mmci_irq, IRQF_SHARED, DRIVER_NAME " (cmd)", host);
1494 	if (ret)
1495 		goto unmap;
1496 
1497 	if (!dev->irq[1])
1498 		host->singleirq = true;
1499 	else {
1500 		ret = request_irq(dev->irq[1], mmci_pio_irq, IRQF_SHARED,
1501 				  DRIVER_NAME " (pio)", host);
1502 		if (ret)
1503 			goto irq0_free;
1504 	}
1505 
1506 	writel(MCI_IRQENABLE, host->base + MMCIMASK0);
1507 
1508 	amba_set_drvdata(dev, mmc);
1509 
1510 	dev_info(&dev->dev, "%s: PL%03x manf %x rev%u at 0x%08llx irq %d,%d (pio)\n",
1511 		 mmc_hostname(mmc), amba_part(dev), amba_manf(dev),
1512 		 amba_rev(dev), (unsigned long long)dev->res.start,
1513 		 dev->irq[0], dev->irq[1]);
1514 
1515 	mmci_dma_setup(host);
1516 
1517 	pm_runtime_set_autosuspend_delay(&dev->dev, 50);
1518 	pm_runtime_use_autosuspend(&dev->dev);
1519 	pm_runtime_put(&dev->dev);
1520 
1521 	mmc_add_host(mmc);
1522 
1523 	return 0;
1524 
1525  irq0_free:
1526 	free_irq(dev->irq[0], host);
1527  unmap:
1528 	if (host->gpio_wp != -ENOSYS)
1529 		gpio_free(host->gpio_wp);
1530  err_gpio_wp:
1531 	if (host->gpio_cd_irq >= 0)
1532 		free_irq(host->gpio_cd_irq, host);
1533 	if (host->gpio_cd != -ENOSYS)
1534 		gpio_free(host->gpio_cd);
1535  err_gpio_cd:
1536 	iounmap(host->base);
1537  clk_disable:
1538 	clk_disable_unprepare(host->clk);
1539  clk_free:
1540 	clk_put(host->clk);
1541  host_free:
1542 	mmc_free_host(mmc);
1543  rel_regions:
1544 	amba_release_regions(dev);
1545  out:
1546 	return ret;
1547 }
1548 
1549 static int mmci_remove(struct amba_device *dev)
1550 {
1551 	struct mmc_host *mmc = amba_get_drvdata(dev);
1552 
1553 	amba_set_drvdata(dev, NULL);
1554 
1555 	if (mmc) {
1556 		struct mmci_host *host = mmc_priv(mmc);
1557 
1558 		/*
1559 		 * Undo pm_runtime_put() in probe.  We use the _sync
1560 		 * version here so that we can access the primecell.
1561 		 */
1562 		pm_runtime_get_sync(&dev->dev);
1563 
1564 		mmc_remove_host(mmc);
1565 
1566 		writel(0, host->base + MMCIMASK0);
1567 		writel(0, host->base + MMCIMASK1);
1568 
1569 		writel(0, host->base + MMCICOMMAND);
1570 		writel(0, host->base + MMCIDATACTRL);
1571 
1572 		mmci_dma_release(host);
1573 		free_irq(dev->irq[0], host);
1574 		if (!host->singleirq)
1575 			free_irq(dev->irq[1], host);
1576 
1577 		if (host->gpio_wp != -ENOSYS)
1578 			gpio_free(host->gpio_wp);
1579 		if (host->gpio_cd_irq >= 0)
1580 			free_irq(host->gpio_cd_irq, host);
1581 		if (host->gpio_cd != -ENOSYS)
1582 			gpio_free(host->gpio_cd);
1583 
1584 		iounmap(host->base);
1585 		clk_disable_unprepare(host->clk);
1586 		clk_put(host->clk);
1587 
1588 		if (host->vcc)
1589 			mmc_regulator_set_ocr(mmc, host->vcc, 0);
1590 		regulator_put(host->vcc);
1591 
1592 		mmc_free_host(mmc);
1593 
1594 		amba_release_regions(dev);
1595 	}
1596 
1597 	return 0;
1598 }
1599 
1600 #ifdef CONFIG_SUSPEND
1601 static int mmci_suspend(struct device *dev)
1602 {
1603 	struct amba_device *adev = to_amba_device(dev);
1604 	struct mmc_host *mmc = amba_get_drvdata(adev);
1605 	int ret = 0;
1606 
1607 	if (mmc) {
1608 		struct mmci_host *host = mmc_priv(mmc);
1609 
1610 		ret = mmc_suspend_host(mmc);
1611 		if (ret == 0) {
1612 			pm_runtime_get_sync(dev);
1613 			writel(0, host->base + MMCIMASK0);
1614 		}
1615 	}
1616 
1617 	return ret;
1618 }
1619 
1620 static int mmci_resume(struct device *dev)
1621 {
1622 	struct amba_device *adev = to_amba_device(dev);
1623 	struct mmc_host *mmc = amba_get_drvdata(adev);
1624 	int ret = 0;
1625 
1626 	if (mmc) {
1627 		struct mmci_host *host = mmc_priv(mmc);
1628 
1629 		writel(MCI_IRQENABLE, host->base + MMCIMASK0);
1630 		pm_runtime_put(dev);
1631 
1632 		ret = mmc_resume_host(mmc);
1633 	}
1634 
1635 	return ret;
1636 }
1637 #endif
1638 
1639 static const struct dev_pm_ops mmci_dev_pm_ops = {
1640 	SET_SYSTEM_SLEEP_PM_OPS(mmci_suspend, mmci_resume)
1641 };
1642 
1643 static struct amba_id mmci_ids[] = {
1644 	{
1645 		.id	= 0x00041180,
1646 		.mask	= 0xff0fffff,
1647 		.data	= &variant_arm,
1648 	},
1649 	{
1650 		.id	= 0x01041180,
1651 		.mask	= 0xff0fffff,
1652 		.data	= &variant_arm_extended_fifo,
1653 	},
1654 	{
1655 		.id	= 0x00041181,
1656 		.mask	= 0x000fffff,
1657 		.data	= &variant_arm,
1658 	},
1659 	/* ST Micro variants */
1660 	{
1661 		.id     = 0x00180180,
1662 		.mask   = 0x00ffffff,
1663 		.data	= &variant_u300,
1664 	},
1665 	{
1666 		.id     = 0x10180180,
1667 		.mask   = 0xf0ffffff,
1668 		.data	= &variant_nomadik,
1669 	},
1670 	{
1671 		.id     = 0x00280180,
1672 		.mask   = 0x00ffffff,
1673 		.data	= &variant_u300,
1674 	},
1675 	{
1676 		.id     = 0x00480180,
1677 		.mask   = 0xf0ffffff,
1678 		.data	= &variant_ux500,
1679 	},
1680 	{
1681 		.id     = 0x10480180,
1682 		.mask   = 0xf0ffffff,
1683 		.data	= &variant_ux500v2,
1684 	},
1685 	{ 0, 0 },
1686 };
1687 
1688 MODULE_DEVICE_TABLE(amba, mmci_ids);
1689 
1690 static struct amba_driver mmci_driver = {
1691 	.drv		= {
1692 		.name	= DRIVER_NAME,
1693 		.pm	= &mmci_dev_pm_ops,
1694 	},
1695 	.probe		= mmci_probe,
1696 	.remove		= mmci_remove,
1697 	.id_table	= mmci_ids,
1698 };
1699 
1700 module_amba_driver(mmci_driver);
1701 
1702 module_param(fmax, uint, 0444);
1703 
1704 MODULE_DESCRIPTION("ARM PrimeCell PL180/181 Multimedia Card Interface driver");
1705 MODULE_LICENSE("GPL");
1706