xref: /openbmc/linux/drivers/mmc/host/mmci.c (revision 95c96174)
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/delay.h>
19 #include <linux/err.h>
20 #include <linux/highmem.h>
21 #include <linux/log2.h>
22 #include <linux/mmc/host.h>
23 #include <linux/mmc/card.h>
24 #include <linux/amba/bus.h>
25 #include <linux/clk.h>
26 #include <linux/scatterlist.h>
27 #include <linux/gpio.h>
28 #include <linux/regulator/consumer.h>
29 #include <linux/dmaengine.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/amba/mmci.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/types.h>
34 
35 #include <asm/div64.h>
36 #include <asm/io.h>
37 #include <asm/sizes.h>
38 
39 #include "mmci.h"
40 
41 #define DRIVER_NAME "mmci-pl18x"
42 
43 static unsigned int fmax = 515633;
44 
45 /**
46  * struct variant_data - MMCI variant-specific quirks
47  * @clkreg: default value for MCICLOCK register
48  * @clkreg_enable: enable value for MMCICLOCK register
49  * @datalength_bits: number of bits in the MMCIDATALENGTH register
50  * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
51  *	      is asserted (likewise for RX)
52  * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY
53  *		  is asserted (likewise for RX)
54  * @sdio: variant supports SDIO
55  * @st_clkdiv: true if using a ST-specific clock divider algorithm
56  * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register
57  * @pwrreg_powerup: power up value for MMCIPOWER register
58  * @signal_direction: input/out direction of bus signals can be indicated
59  */
60 struct variant_data {
61 	unsigned int		clkreg;
62 	unsigned int		clkreg_enable;
63 	unsigned int		datalength_bits;
64 	unsigned int		fifosize;
65 	unsigned int		fifohalfsize;
66 	bool			sdio;
67 	bool			st_clkdiv;
68 	bool			blksz_datactrl16;
69 	u32			pwrreg_powerup;
70 	bool			signal_direction;
71 };
72 
73 static struct variant_data variant_arm = {
74 	.fifosize		= 16 * 4,
75 	.fifohalfsize		= 8 * 4,
76 	.datalength_bits	= 16,
77 	.pwrreg_powerup		= MCI_PWR_UP,
78 };
79 
80 static struct variant_data variant_arm_extended_fifo = {
81 	.fifosize		= 128 * 4,
82 	.fifohalfsize		= 64 * 4,
83 	.datalength_bits	= 16,
84 	.pwrreg_powerup		= MCI_PWR_UP,
85 };
86 
87 static struct variant_data variant_u300 = {
88 	.fifosize		= 16 * 4,
89 	.fifohalfsize		= 8 * 4,
90 	.clkreg_enable		= MCI_ST_U300_HWFCEN,
91 	.datalength_bits	= 16,
92 	.sdio			= true,
93 	.pwrreg_powerup		= MCI_PWR_ON,
94 	.signal_direction	= true,
95 };
96 
97 static struct variant_data variant_ux500 = {
98 	.fifosize		= 30 * 4,
99 	.fifohalfsize		= 8 * 4,
100 	.clkreg			= MCI_CLK_ENABLE,
101 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
102 	.datalength_bits	= 24,
103 	.sdio			= true,
104 	.st_clkdiv		= true,
105 	.pwrreg_powerup		= MCI_PWR_ON,
106 	.signal_direction	= true,
107 };
108 
109 static struct variant_data variant_ux500v2 = {
110 	.fifosize		= 30 * 4,
111 	.fifohalfsize		= 8 * 4,
112 	.clkreg			= MCI_CLK_ENABLE,
113 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
114 	.datalength_bits	= 24,
115 	.sdio			= true,
116 	.st_clkdiv		= true,
117 	.blksz_datactrl16	= true,
118 	.pwrreg_powerup		= MCI_PWR_ON,
119 	.signal_direction	= true,
120 };
121 
122 /*
123  * This must be called with host->lock held
124  */
125 static void mmci_write_clkreg(struct mmci_host *host, u32 clk)
126 {
127 	if (host->clk_reg != clk) {
128 		host->clk_reg = clk;
129 		writel(clk, host->base + MMCICLOCK);
130 	}
131 }
132 
133 /*
134  * This must be called with host->lock held
135  */
136 static void mmci_write_pwrreg(struct mmci_host *host, u32 pwr)
137 {
138 	if (host->pwr_reg != pwr) {
139 		host->pwr_reg = pwr;
140 		writel(pwr, host->base + MMCIPOWER);
141 	}
142 }
143 
144 /*
145  * This must be called with host->lock held
146  */
147 static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
148 {
149 	struct variant_data *variant = host->variant;
150 	u32 clk = variant->clkreg;
151 
152 	if (desired) {
153 		if (desired >= host->mclk) {
154 			clk = MCI_CLK_BYPASS;
155 			if (variant->st_clkdiv)
156 				clk |= MCI_ST_UX500_NEG_EDGE;
157 			host->cclk = host->mclk;
158 		} else if (variant->st_clkdiv) {
159 			/*
160 			 * DB8500 TRM says f = mclk / (clkdiv + 2)
161 			 * => clkdiv = (mclk / f) - 2
162 			 * Round the divider up so we don't exceed the max
163 			 * frequency
164 			 */
165 			clk = DIV_ROUND_UP(host->mclk, desired) - 2;
166 			if (clk >= 256)
167 				clk = 255;
168 			host->cclk = host->mclk / (clk + 2);
169 		} else {
170 			/*
171 			 * PL180 TRM says f = mclk / (2 * (clkdiv + 1))
172 			 * => clkdiv = mclk / (2 * f) - 1
173 			 */
174 			clk = host->mclk / (2 * desired) - 1;
175 			if (clk >= 256)
176 				clk = 255;
177 			host->cclk = host->mclk / (2 * (clk + 1));
178 		}
179 
180 		clk |= variant->clkreg_enable;
181 		clk |= MCI_CLK_ENABLE;
182 		/* This hasn't proven to be worthwhile */
183 		/* clk |= MCI_CLK_PWRSAVE; */
184 	}
185 
186 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
187 		clk |= MCI_4BIT_BUS;
188 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
189 		clk |= MCI_ST_8BIT_BUS;
190 
191 	mmci_write_clkreg(host, clk);
192 }
193 
194 static void
195 mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
196 {
197 	writel(0, host->base + MMCICOMMAND);
198 
199 	BUG_ON(host->data);
200 
201 	host->mrq = NULL;
202 	host->cmd = NULL;
203 
204 	mmc_request_done(host->mmc, mrq);
205 
206 	pm_runtime_mark_last_busy(mmc_dev(host->mmc));
207 	pm_runtime_put_autosuspend(mmc_dev(host->mmc));
208 }
209 
210 static void mmci_set_mask1(struct mmci_host *host, unsigned int mask)
211 {
212 	void __iomem *base = host->base;
213 
214 	if (host->singleirq) {
215 		unsigned int mask0 = readl(base + MMCIMASK0);
216 
217 		mask0 &= ~MCI_IRQ1MASK;
218 		mask0 |= mask;
219 
220 		writel(mask0, base + MMCIMASK0);
221 	}
222 
223 	writel(mask, base + MMCIMASK1);
224 }
225 
226 static void mmci_stop_data(struct mmci_host *host)
227 {
228 	writel(0, host->base + MMCIDATACTRL);
229 	mmci_set_mask1(host, 0);
230 	host->data = NULL;
231 }
232 
233 static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
234 {
235 	unsigned int flags = SG_MITER_ATOMIC;
236 
237 	if (data->flags & MMC_DATA_READ)
238 		flags |= SG_MITER_TO_SG;
239 	else
240 		flags |= SG_MITER_FROM_SG;
241 
242 	sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
243 }
244 
245 /*
246  * All the DMA operation mode stuff goes inside this ifdef.
247  * This assumes that you have a generic DMA device interface,
248  * no custom DMA interfaces are supported.
249  */
250 #ifdef CONFIG_DMA_ENGINE
251 static void __devinit mmci_dma_setup(struct mmci_host *host)
252 {
253 	struct mmci_platform_data *plat = host->plat;
254 	const char *rxname, *txname;
255 	dma_cap_mask_t mask;
256 
257 	if (!plat || !plat->dma_filter) {
258 		dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
259 		return;
260 	}
261 
262 	/* initialize pre request cookie */
263 	host->next_data.cookie = 1;
264 
265 	/* Try to acquire a generic DMA engine slave channel */
266 	dma_cap_zero(mask);
267 	dma_cap_set(DMA_SLAVE, mask);
268 
269 	/*
270 	 * If only an RX channel is specified, the driver will
271 	 * attempt to use it bidirectionally, however if it is
272 	 * is specified but cannot be located, DMA will be disabled.
273 	 */
274 	if (plat->dma_rx_param) {
275 		host->dma_rx_channel = dma_request_channel(mask,
276 							   plat->dma_filter,
277 							   plat->dma_rx_param);
278 		/* E.g if no DMA hardware is present */
279 		if (!host->dma_rx_channel)
280 			dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
281 	}
282 
283 	if (plat->dma_tx_param) {
284 		host->dma_tx_channel = dma_request_channel(mask,
285 							   plat->dma_filter,
286 							   plat->dma_tx_param);
287 		if (!host->dma_tx_channel)
288 			dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
289 	} else {
290 		host->dma_tx_channel = host->dma_rx_channel;
291 	}
292 
293 	if (host->dma_rx_channel)
294 		rxname = dma_chan_name(host->dma_rx_channel);
295 	else
296 		rxname = "none";
297 
298 	if (host->dma_tx_channel)
299 		txname = dma_chan_name(host->dma_tx_channel);
300 	else
301 		txname = "none";
302 
303 	dev_info(mmc_dev(host->mmc), "DMA channels RX %s, TX %s\n",
304 		 rxname, txname);
305 
306 	/*
307 	 * Limit the maximum segment size in any SG entry according to
308 	 * the parameters of the DMA engine device.
309 	 */
310 	if (host->dma_tx_channel) {
311 		struct device *dev = host->dma_tx_channel->device->dev;
312 		unsigned int max_seg_size = dma_get_max_seg_size(dev);
313 
314 		if (max_seg_size < host->mmc->max_seg_size)
315 			host->mmc->max_seg_size = max_seg_size;
316 	}
317 	if (host->dma_rx_channel) {
318 		struct device *dev = host->dma_rx_channel->device->dev;
319 		unsigned int max_seg_size = dma_get_max_seg_size(dev);
320 
321 		if (max_seg_size < host->mmc->max_seg_size)
322 			host->mmc->max_seg_size = max_seg_size;
323 	}
324 }
325 
326 /*
327  * This is used in __devinit or __devexit so inline it
328  * so it can be discarded.
329  */
330 static inline void mmci_dma_release(struct mmci_host *host)
331 {
332 	struct mmci_platform_data *plat = host->plat;
333 
334 	if (host->dma_rx_channel)
335 		dma_release_channel(host->dma_rx_channel);
336 	if (host->dma_tx_channel && plat->dma_tx_param)
337 		dma_release_channel(host->dma_tx_channel);
338 	host->dma_rx_channel = host->dma_tx_channel = NULL;
339 }
340 
341 static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
342 {
343 	struct dma_chan *chan = host->dma_current;
344 	enum dma_data_direction dir;
345 	u32 status;
346 	int i;
347 
348 	/* Wait up to 1ms for the DMA to complete */
349 	for (i = 0; ; i++) {
350 		status = readl(host->base + MMCISTATUS);
351 		if (!(status & MCI_RXDATAAVLBLMASK) || i >= 100)
352 			break;
353 		udelay(10);
354 	}
355 
356 	/*
357 	 * Check to see whether we still have some data left in the FIFO -
358 	 * this catches DMA controllers which are unable to monitor the
359 	 * DMALBREQ and DMALSREQ signals while allowing us to DMA to non-
360 	 * contiguous buffers.  On TX, we'll get a FIFO underrun error.
361 	 */
362 	if (status & MCI_RXDATAAVLBLMASK) {
363 		dmaengine_terminate_all(chan);
364 		if (!data->error)
365 			data->error = -EIO;
366 	}
367 
368 	if (data->flags & MMC_DATA_WRITE) {
369 		dir = DMA_TO_DEVICE;
370 	} else {
371 		dir = DMA_FROM_DEVICE;
372 	}
373 
374 	if (!data->host_cookie)
375 		dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
376 
377 	/*
378 	 * Use of DMA with scatter-gather is impossible.
379 	 * Give up with DMA and switch back to PIO mode.
380 	 */
381 	if (status & MCI_RXDATAAVLBLMASK) {
382 		dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
383 		mmci_dma_release(host);
384 	}
385 }
386 
387 static void mmci_dma_data_error(struct mmci_host *host)
388 {
389 	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
390 	dmaengine_terminate_all(host->dma_current);
391 }
392 
393 static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
394 			      struct mmci_host_next *next)
395 {
396 	struct variant_data *variant = host->variant;
397 	struct dma_slave_config conf = {
398 		.src_addr = host->phybase + MMCIFIFO,
399 		.dst_addr = host->phybase + MMCIFIFO,
400 		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
401 		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
402 		.src_maxburst = variant->fifohalfsize >> 2, /* # of words */
403 		.dst_maxburst = variant->fifohalfsize >> 2, /* # of words */
404 		.device_fc = false,
405 	};
406 	struct dma_chan *chan;
407 	struct dma_device *device;
408 	struct dma_async_tx_descriptor *desc;
409 	enum dma_data_direction buffer_dirn;
410 	int nr_sg;
411 
412 	/* Check if next job is already prepared */
413 	if (data->host_cookie && !next &&
414 	    host->dma_current && host->dma_desc_current)
415 		return 0;
416 
417 	if (!next) {
418 		host->dma_current = NULL;
419 		host->dma_desc_current = NULL;
420 	}
421 
422 	if (data->flags & MMC_DATA_READ) {
423 		conf.direction = DMA_DEV_TO_MEM;
424 		buffer_dirn = DMA_FROM_DEVICE;
425 		chan = host->dma_rx_channel;
426 	} else {
427 		conf.direction = DMA_MEM_TO_DEV;
428 		buffer_dirn = DMA_TO_DEVICE;
429 		chan = host->dma_tx_channel;
430 	}
431 
432 	/* If there's no DMA channel, fall back to PIO */
433 	if (!chan)
434 		return -EINVAL;
435 
436 	/* If less than or equal to the fifo size, don't bother with DMA */
437 	if (data->blksz * data->blocks <= variant->fifosize)
438 		return -EINVAL;
439 
440 	device = chan->device;
441 	nr_sg = dma_map_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
442 	if (nr_sg == 0)
443 		return -EINVAL;
444 
445 	dmaengine_slave_config(chan, &conf);
446 	desc = dmaengine_prep_slave_sg(chan, data->sg, nr_sg,
447 					    conf.direction, DMA_CTRL_ACK);
448 	if (!desc)
449 		goto unmap_exit;
450 
451 	if (next) {
452 		next->dma_chan = chan;
453 		next->dma_desc = desc;
454 	} else {
455 		host->dma_current = chan;
456 		host->dma_desc_current = desc;
457 	}
458 
459 	return 0;
460 
461  unmap_exit:
462 	if (!next)
463 		dmaengine_terminate_all(chan);
464 	dma_unmap_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
465 	return -ENOMEM;
466 }
467 
468 static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
469 {
470 	int ret;
471 	struct mmc_data *data = host->data;
472 
473 	ret = mmci_dma_prep_data(host, host->data, NULL);
474 	if (ret)
475 		return ret;
476 
477 	/* Okay, go for it. */
478 	dev_vdbg(mmc_dev(host->mmc),
479 		 "Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
480 		 data->sg_len, data->blksz, data->blocks, data->flags);
481 	dmaengine_submit(host->dma_desc_current);
482 	dma_async_issue_pending(host->dma_current);
483 
484 	datactrl |= MCI_DPSM_DMAENABLE;
485 
486 	/* Trigger the DMA transfer */
487 	writel(datactrl, host->base + MMCIDATACTRL);
488 
489 	/*
490 	 * Let the MMCI say when the data is ended and it's time
491 	 * to fire next DMA request. When that happens, MMCI will
492 	 * call mmci_data_end()
493 	 */
494 	writel(readl(host->base + MMCIMASK0) | MCI_DATAENDMASK,
495 	       host->base + MMCIMASK0);
496 	return 0;
497 }
498 
499 static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
500 {
501 	struct mmci_host_next *next = &host->next_data;
502 
503 	if (data->host_cookie && data->host_cookie != next->cookie) {
504 		pr_warning("[%s] invalid cookie: data->host_cookie %d"
505 		       " host->next_data.cookie %d\n",
506 		       __func__, data->host_cookie, host->next_data.cookie);
507 		data->host_cookie = 0;
508 	}
509 
510 	if (!data->host_cookie)
511 		return;
512 
513 	host->dma_desc_current = next->dma_desc;
514 	host->dma_current = next->dma_chan;
515 
516 	next->dma_desc = NULL;
517 	next->dma_chan = NULL;
518 }
519 
520 static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq,
521 			     bool is_first_req)
522 {
523 	struct mmci_host *host = mmc_priv(mmc);
524 	struct mmc_data *data = mrq->data;
525 	struct mmci_host_next *nd = &host->next_data;
526 
527 	if (!data)
528 		return;
529 
530 	if (data->host_cookie) {
531 		data->host_cookie = 0;
532 		return;
533 	}
534 
535 	/* if config for dma */
536 	if (((data->flags & MMC_DATA_WRITE) && host->dma_tx_channel) ||
537 	    ((data->flags & MMC_DATA_READ) && host->dma_rx_channel)) {
538 		if (mmci_dma_prep_data(host, data, nd))
539 			data->host_cookie = 0;
540 		else
541 			data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
542 	}
543 }
544 
545 static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
546 			      int err)
547 {
548 	struct mmci_host *host = mmc_priv(mmc);
549 	struct mmc_data *data = mrq->data;
550 	struct dma_chan *chan;
551 	enum dma_data_direction dir;
552 
553 	if (!data)
554 		return;
555 
556 	if (data->flags & MMC_DATA_READ) {
557 		dir = DMA_FROM_DEVICE;
558 		chan = host->dma_rx_channel;
559 	} else {
560 		dir = DMA_TO_DEVICE;
561 		chan = host->dma_tx_channel;
562 	}
563 
564 
565 	/* if config for dma */
566 	if (chan) {
567 		if (err)
568 			dmaengine_terminate_all(chan);
569 		if (data->host_cookie)
570 			dma_unmap_sg(mmc_dev(host->mmc), data->sg,
571 				     data->sg_len, dir);
572 		mrq->data->host_cookie = 0;
573 	}
574 }
575 
576 #else
577 /* Blank functions if the DMA engine is not available */
578 static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
579 {
580 }
581 static inline void mmci_dma_setup(struct mmci_host *host)
582 {
583 }
584 
585 static inline void mmci_dma_release(struct mmci_host *host)
586 {
587 }
588 
589 static inline void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
590 {
591 }
592 
593 static inline void mmci_dma_data_error(struct mmci_host *host)
594 {
595 }
596 
597 static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
598 {
599 	return -ENOSYS;
600 }
601 
602 #define mmci_pre_request NULL
603 #define mmci_post_request NULL
604 
605 #endif
606 
607 static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
608 {
609 	struct variant_data *variant = host->variant;
610 	unsigned int datactrl, timeout, irqmask;
611 	unsigned long long clks;
612 	void __iomem *base;
613 	int blksz_bits;
614 
615 	dev_dbg(mmc_dev(host->mmc), "blksz %04x blks %04x flags %08x\n",
616 		data->blksz, data->blocks, data->flags);
617 
618 	host->data = data;
619 	host->size = data->blksz * data->blocks;
620 	data->bytes_xfered = 0;
621 
622 	clks = (unsigned long long)data->timeout_ns * host->cclk;
623 	do_div(clks, 1000000000UL);
624 
625 	timeout = data->timeout_clks + (unsigned int)clks;
626 
627 	base = host->base;
628 	writel(timeout, base + MMCIDATATIMER);
629 	writel(host->size, base + MMCIDATALENGTH);
630 
631 	blksz_bits = ffs(data->blksz) - 1;
632 	BUG_ON(1 << blksz_bits != data->blksz);
633 
634 	if (variant->blksz_datactrl16)
635 		datactrl = MCI_DPSM_ENABLE | (data->blksz << 16);
636 	else
637 		datactrl = MCI_DPSM_ENABLE | blksz_bits << 4;
638 
639 	if (data->flags & MMC_DATA_READ)
640 		datactrl |= MCI_DPSM_DIRECTION;
641 
642 	/* The ST Micro variants has a special bit to enable SDIO */
643 	if (variant->sdio && host->mmc->card)
644 		if (mmc_card_sdio(host->mmc->card))
645 			datactrl |= MCI_ST_DPSM_SDIOEN;
646 
647 	/*
648 	 * Attempt to use DMA operation mode, if this
649 	 * should fail, fall back to PIO mode
650 	 */
651 	if (!mmci_dma_start_data(host, datactrl))
652 		return;
653 
654 	/* IRQ mode, map the SG list for CPU reading/writing */
655 	mmci_init_sg(host, data);
656 
657 	if (data->flags & MMC_DATA_READ) {
658 		irqmask = MCI_RXFIFOHALFFULLMASK;
659 
660 		/*
661 		 * If we have less than the fifo 'half-full' threshold to
662 		 * transfer, trigger a PIO interrupt as soon as any data
663 		 * is available.
664 		 */
665 		if (host->size < variant->fifohalfsize)
666 			irqmask |= MCI_RXDATAAVLBLMASK;
667 	} else {
668 		/*
669 		 * We don't actually need to include "FIFO empty" here
670 		 * since its implicit in "FIFO half empty".
671 		 */
672 		irqmask = MCI_TXFIFOHALFEMPTYMASK;
673 	}
674 
675 	writel(datactrl, base + MMCIDATACTRL);
676 	writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
677 	mmci_set_mask1(host, irqmask);
678 }
679 
680 static void
681 mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
682 {
683 	void __iomem *base = host->base;
684 
685 	dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
686 	    cmd->opcode, cmd->arg, cmd->flags);
687 
688 	if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
689 		writel(0, base + MMCICOMMAND);
690 		udelay(1);
691 	}
692 
693 	c |= cmd->opcode | MCI_CPSM_ENABLE;
694 	if (cmd->flags & MMC_RSP_PRESENT) {
695 		if (cmd->flags & MMC_RSP_136)
696 			c |= MCI_CPSM_LONGRSP;
697 		c |= MCI_CPSM_RESPONSE;
698 	}
699 	if (/*interrupt*/0)
700 		c |= MCI_CPSM_INTERRUPT;
701 
702 	host->cmd = cmd;
703 
704 	writel(cmd->arg, base + MMCIARGUMENT);
705 	writel(c, base + MMCICOMMAND);
706 }
707 
708 static void
709 mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
710 	      unsigned int status)
711 {
712 	/* First check for errors */
713 	if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_STARTBITERR|
714 		      MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
715 		u32 remain, success;
716 
717 		/* Terminate the DMA transfer */
718 		if (dma_inprogress(host))
719 			mmci_dma_data_error(host);
720 
721 		/*
722 		 * Calculate how far we are into the transfer.  Note that
723 		 * the data counter gives the number of bytes transferred
724 		 * on the MMC bus, not on the host side.  On reads, this
725 		 * can be as much as a FIFO-worth of data ahead.  This
726 		 * matters for FIFO overruns only.
727 		 */
728 		remain = readl(host->base + MMCIDATACNT);
729 		success = data->blksz * data->blocks - remain;
730 
731 		dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ, status 0x%08x at 0x%08x\n",
732 			status, success);
733 		if (status & MCI_DATACRCFAIL) {
734 			/* Last block was not successful */
735 			success -= 1;
736 			data->error = -EILSEQ;
737 		} else if (status & MCI_DATATIMEOUT) {
738 			data->error = -ETIMEDOUT;
739 		} else if (status & MCI_STARTBITERR) {
740 			data->error = -ECOMM;
741 		} else if (status & MCI_TXUNDERRUN) {
742 			data->error = -EIO;
743 		} else if (status & MCI_RXOVERRUN) {
744 			if (success > host->variant->fifosize)
745 				success -= host->variant->fifosize;
746 			else
747 				success = 0;
748 			data->error = -EIO;
749 		}
750 		data->bytes_xfered = round_down(success, data->blksz);
751 	}
752 
753 	if (status & MCI_DATABLOCKEND)
754 		dev_err(mmc_dev(host->mmc), "stray MCI_DATABLOCKEND interrupt\n");
755 
756 	if (status & MCI_DATAEND || data->error) {
757 		if (dma_inprogress(host))
758 			mmci_dma_unmap(host, data);
759 		mmci_stop_data(host);
760 
761 		if (!data->error)
762 			/* The error clause is handled above, success! */
763 			data->bytes_xfered = data->blksz * data->blocks;
764 
765 		if (!data->stop) {
766 			mmci_request_end(host, data->mrq);
767 		} else {
768 			mmci_start_command(host, data->stop, 0);
769 		}
770 	}
771 }
772 
773 static void
774 mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
775 	     unsigned int status)
776 {
777 	void __iomem *base = host->base;
778 
779 	host->cmd = NULL;
780 
781 	if (status & MCI_CMDTIMEOUT) {
782 		cmd->error = -ETIMEDOUT;
783 	} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
784 		cmd->error = -EILSEQ;
785 	} else {
786 		cmd->resp[0] = readl(base + MMCIRESPONSE0);
787 		cmd->resp[1] = readl(base + MMCIRESPONSE1);
788 		cmd->resp[2] = readl(base + MMCIRESPONSE2);
789 		cmd->resp[3] = readl(base + MMCIRESPONSE3);
790 	}
791 
792 	if (!cmd->data || cmd->error) {
793 		if (host->data) {
794 			/* Terminate the DMA transfer */
795 			if (dma_inprogress(host))
796 				mmci_dma_data_error(host);
797 			mmci_stop_data(host);
798 		}
799 		mmci_request_end(host, cmd->mrq);
800 	} else if (!(cmd->data->flags & MMC_DATA_READ)) {
801 		mmci_start_data(host, cmd->data);
802 	}
803 }
804 
805 static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain)
806 {
807 	void __iomem *base = host->base;
808 	char *ptr = buffer;
809 	u32 status;
810 	int host_remain = host->size;
811 
812 	do {
813 		int count = host_remain - (readl(base + MMCIFIFOCNT) << 2);
814 
815 		if (count > remain)
816 			count = remain;
817 
818 		if (count <= 0)
819 			break;
820 
821 		/*
822 		 * SDIO especially may want to send something that is
823 		 * not divisible by 4 (as opposed to card sectors
824 		 * etc). Therefore make sure to always read the last bytes
825 		 * while only doing full 32-bit reads towards the FIFO.
826 		 */
827 		if (unlikely(count & 0x3)) {
828 			if (count < 4) {
829 				unsigned char buf[4];
830 				readsl(base + MMCIFIFO, buf, 1);
831 				memcpy(ptr, buf, count);
832 			} else {
833 				readsl(base + MMCIFIFO, ptr, count >> 2);
834 				count &= ~0x3;
835 			}
836 		} else {
837 			readsl(base + MMCIFIFO, ptr, count >> 2);
838 		}
839 
840 		ptr += count;
841 		remain -= count;
842 		host_remain -= count;
843 
844 		if (remain == 0)
845 			break;
846 
847 		status = readl(base + MMCISTATUS);
848 	} while (status & MCI_RXDATAAVLBL);
849 
850 	return ptr - buffer;
851 }
852 
853 static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int remain, u32 status)
854 {
855 	struct variant_data *variant = host->variant;
856 	void __iomem *base = host->base;
857 	char *ptr = buffer;
858 
859 	do {
860 		unsigned int count, maxcnt;
861 
862 		maxcnt = status & MCI_TXFIFOEMPTY ?
863 			 variant->fifosize : variant->fifohalfsize;
864 		count = min(remain, maxcnt);
865 
866 		/*
867 		 * The ST Micro variant for SDIO transfer sizes
868 		 * less then 8 bytes should have clock H/W flow
869 		 * control disabled.
870 		 */
871 		if (variant->sdio &&
872 		    mmc_card_sdio(host->mmc->card)) {
873 			u32 clk;
874 			if (count < 8)
875 				clk = host->clk_reg & ~variant->clkreg_enable;
876 			else
877 				clk = host->clk_reg | variant->clkreg_enable;
878 
879 			mmci_write_clkreg(host, clk);
880 		}
881 
882 		/*
883 		 * SDIO especially may want to send something that is
884 		 * not divisible by 4 (as opposed to card sectors
885 		 * etc), and the FIFO only accept full 32-bit writes.
886 		 * So compensate by adding +3 on the count, a single
887 		 * byte become a 32bit write, 7 bytes will be two
888 		 * 32bit writes etc.
889 		 */
890 		writesl(base + MMCIFIFO, ptr, (count + 3) >> 2);
891 
892 		ptr += count;
893 		remain -= count;
894 
895 		if (remain == 0)
896 			break;
897 
898 		status = readl(base + MMCISTATUS);
899 	} while (status & MCI_TXFIFOHALFEMPTY);
900 
901 	return ptr - buffer;
902 }
903 
904 /*
905  * PIO data transfer IRQ handler.
906  */
907 static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
908 {
909 	struct mmci_host *host = dev_id;
910 	struct sg_mapping_iter *sg_miter = &host->sg_miter;
911 	struct variant_data *variant = host->variant;
912 	void __iomem *base = host->base;
913 	unsigned long flags;
914 	u32 status;
915 
916 	status = readl(base + MMCISTATUS);
917 
918 	dev_dbg(mmc_dev(host->mmc), "irq1 (pio) %08x\n", status);
919 
920 	local_irq_save(flags);
921 
922 	do {
923 		unsigned int remain, len;
924 		char *buffer;
925 
926 		/*
927 		 * For write, we only need to test the half-empty flag
928 		 * here - if the FIFO is completely empty, then by
929 		 * definition it is more than half empty.
930 		 *
931 		 * For read, check for data available.
932 		 */
933 		if (!(status & (MCI_TXFIFOHALFEMPTY|MCI_RXDATAAVLBL)))
934 			break;
935 
936 		if (!sg_miter_next(sg_miter))
937 			break;
938 
939 		buffer = sg_miter->addr;
940 		remain = sg_miter->length;
941 
942 		len = 0;
943 		if (status & MCI_RXACTIVE)
944 			len = mmci_pio_read(host, buffer, remain);
945 		if (status & MCI_TXACTIVE)
946 			len = mmci_pio_write(host, buffer, remain, status);
947 
948 		sg_miter->consumed = len;
949 
950 		host->size -= len;
951 		remain -= len;
952 
953 		if (remain)
954 			break;
955 
956 		status = readl(base + MMCISTATUS);
957 	} while (1);
958 
959 	sg_miter_stop(sg_miter);
960 
961 	local_irq_restore(flags);
962 
963 	/*
964 	 * If we have less than the fifo 'half-full' threshold to transfer,
965 	 * trigger a PIO interrupt as soon as any data is available.
966 	 */
967 	if (status & MCI_RXACTIVE && host->size < variant->fifohalfsize)
968 		mmci_set_mask1(host, MCI_RXDATAAVLBLMASK);
969 
970 	/*
971 	 * If we run out of data, disable the data IRQs; this
972 	 * prevents a race where the FIFO becomes empty before
973 	 * the chip itself has disabled the data path, and
974 	 * stops us racing with our data end IRQ.
975 	 */
976 	if (host->size == 0) {
977 		mmci_set_mask1(host, 0);
978 		writel(readl(base + MMCIMASK0) | MCI_DATAENDMASK, base + MMCIMASK0);
979 	}
980 
981 	return IRQ_HANDLED;
982 }
983 
984 /*
985  * Handle completion of command and data transfers.
986  */
987 static irqreturn_t mmci_irq(int irq, void *dev_id)
988 {
989 	struct mmci_host *host = dev_id;
990 	u32 status;
991 	int ret = 0;
992 
993 	spin_lock(&host->lock);
994 
995 	do {
996 		struct mmc_command *cmd;
997 		struct mmc_data *data;
998 
999 		status = readl(host->base + MMCISTATUS);
1000 
1001 		if (host->singleirq) {
1002 			if (status & readl(host->base + MMCIMASK1))
1003 				mmci_pio_irq(irq, dev_id);
1004 
1005 			status &= ~MCI_IRQ1MASK;
1006 		}
1007 
1008 		status &= readl(host->base + MMCIMASK0);
1009 		writel(status, host->base + MMCICLEAR);
1010 
1011 		dev_dbg(mmc_dev(host->mmc), "irq0 (data+cmd) %08x\n", status);
1012 
1013 		data = host->data;
1014 		if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_STARTBITERR|
1015 			      MCI_TXUNDERRUN|MCI_RXOVERRUN|MCI_DATAEND|
1016 			      MCI_DATABLOCKEND) && data)
1017 			mmci_data_irq(host, data, status);
1018 
1019 		cmd = host->cmd;
1020 		if (status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND) && cmd)
1021 			mmci_cmd_irq(host, cmd, status);
1022 
1023 		ret = 1;
1024 	} while (status);
1025 
1026 	spin_unlock(&host->lock);
1027 
1028 	return IRQ_RETVAL(ret);
1029 }
1030 
1031 static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
1032 {
1033 	struct mmci_host *host = mmc_priv(mmc);
1034 	unsigned long flags;
1035 
1036 	WARN_ON(host->mrq != NULL);
1037 
1038 	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
1039 		dev_err(mmc_dev(mmc), "unsupported block size (%d bytes)\n",
1040 			mrq->data->blksz);
1041 		mrq->cmd->error = -EINVAL;
1042 		mmc_request_done(mmc, mrq);
1043 		return;
1044 	}
1045 
1046 	pm_runtime_get_sync(mmc_dev(mmc));
1047 
1048 	spin_lock_irqsave(&host->lock, flags);
1049 
1050 	host->mrq = mrq;
1051 
1052 	if (mrq->data)
1053 		mmci_get_next_data(host, mrq->data);
1054 
1055 	if (mrq->data && mrq->data->flags & MMC_DATA_READ)
1056 		mmci_start_data(host, mrq->data);
1057 
1058 	mmci_start_command(host, mrq->cmd, 0);
1059 
1060 	spin_unlock_irqrestore(&host->lock, flags);
1061 }
1062 
1063 static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1064 {
1065 	struct mmci_host *host = mmc_priv(mmc);
1066 	struct variant_data *variant = host->variant;
1067 	u32 pwr = 0;
1068 	unsigned long flags;
1069 	int ret;
1070 
1071 	pm_runtime_get_sync(mmc_dev(mmc));
1072 
1073 	if (host->plat->ios_handler &&
1074 		host->plat->ios_handler(mmc_dev(mmc), ios))
1075 			dev_err(mmc_dev(mmc), "platform ios_handler failed\n");
1076 
1077 	switch (ios->power_mode) {
1078 	case MMC_POWER_OFF:
1079 		if (host->vcc)
1080 			ret = mmc_regulator_set_ocr(mmc, host->vcc, 0);
1081 		break;
1082 	case MMC_POWER_UP:
1083 		if (host->vcc) {
1084 			ret = mmc_regulator_set_ocr(mmc, host->vcc, ios->vdd);
1085 			if (ret) {
1086 				dev_err(mmc_dev(mmc), "unable to set OCR\n");
1087 				/*
1088 				 * The .set_ios() function in the mmc_host_ops
1089 				 * struct return void, and failing to set the
1090 				 * power should be rare so we print an error
1091 				 * and return here.
1092 				 */
1093 				goto out;
1094 			}
1095 		}
1096 		/*
1097 		 * The ST Micro variant doesn't have the PL180s MCI_PWR_UP
1098 		 * and instead uses MCI_PWR_ON so apply whatever value is
1099 		 * configured in the variant data.
1100 		 */
1101 		pwr |= variant->pwrreg_powerup;
1102 
1103 		break;
1104 	case MMC_POWER_ON:
1105 		pwr |= MCI_PWR_ON;
1106 		break;
1107 	}
1108 
1109 	if (variant->signal_direction && ios->power_mode != MMC_POWER_OFF) {
1110 		/*
1111 		 * The ST Micro variant has some additional bits
1112 		 * indicating signal direction for the signals in
1113 		 * the SD/MMC bus and feedback-clock usage.
1114 		 */
1115 		pwr |= host->plat->sigdir;
1116 
1117 		if (ios->bus_width == MMC_BUS_WIDTH_4)
1118 			pwr &= ~MCI_ST_DATA74DIREN;
1119 		else if (ios->bus_width == MMC_BUS_WIDTH_1)
1120 			pwr &= (~MCI_ST_DATA74DIREN &
1121 				~MCI_ST_DATA31DIREN &
1122 				~MCI_ST_DATA2DIREN);
1123 	}
1124 
1125 	if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
1126 		if (host->hw_designer != AMBA_VENDOR_ST)
1127 			pwr |= MCI_ROD;
1128 		else {
1129 			/*
1130 			 * The ST Micro variant use the ROD bit for something
1131 			 * else and only has OD (Open Drain).
1132 			 */
1133 			pwr |= MCI_OD;
1134 		}
1135 	}
1136 
1137 	spin_lock_irqsave(&host->lock, flags);
1138 
1139 	mmci_set_clkreg(host, ios->clock);
1140 	mmci_write_pwrreg(host, pwr);
1141 
1142 	spin_unlock_irqrestore(&host->lock, flags);
1143 
1144  out:
1145 	pm_runtime_mark_last_busy(mmc_dev(mmc));
1146 	pm_runtime_put_autosuspend(mmc_dev(mmc));
1147 }
1148 
1149 static int mmci_get_ro(struct mmc_host *mmc)
1150 {
1151 	struct mmci_host *host = mmc_priv(mmc);
1152 
1153 	if (host->gpio_wp == -ENOSYS)
1154 		return -ENOSYS;
1155 
1156 	return gpio_get_value_cansleep(host->gpio_wp);
1157 }
1158 
1159 static int mmci_get_cd(struct mmc_host *mmc)
1160 {
1161 	struct mmci_host *host = mmc_priv(mmc);
1162 	struct mmci_platform_data *plat = host->plat;
1163 	unsigned int status;
1164 
1165 	if (host->gpio_cd == -ENOSYS) {
1166 		if (!plat->status)
1167 			return 1; /* Assume always present */
1168 
1169 		status = plat->status(mmc_dev(host->mmc));
1170 	} else
1171 		status = !!gpio_get_value_cansleep(host->gpio_cd)
1172 			^ plat->cd_invert;
1173 
1174 	/*
1175 	 * Use positive logic throughout - status is zero for no card,
1176 	 * non-zero for card inserted.
1177 	 */
1178 	return status;
1179 }
1180 
1181 static irqreturn_t mmci_cd_irq(int irq, void *dev_id)
1182 {
1183 	struct mmci_host *host = dev_id;
1184 
1185 	mmc_detect_change(host->mmc, msecs_to_jiffies(500));
1186 
1187 	return IRQ_HANDLED;
1188 }
1189 
1190 static const struct mmc_host_ops mmci_ops = {
1191 	.request	= mmci_request,
1192 	.pre_req	= mmci_pre_request,
1193 	.post_req	= mmci_post_request,
1194 	.set_ios	= mmci_set_ios,
1195 	.get_ro		= mmci_get_ro,
1196 	.get_cd		= mmci_get_cd,
1197 };
1198 
1199 static int __devinit mmci_probe(struct amba_device *dev,
1200 	const struct amba_id *id)
1201 {
1202 	struct mmci_platform_data *plat = dev->dev.platform_data;
1203 	struct variant_data *variant = id->data;
1204 	struct mmci_host *host;
1205 	struct mmc_host *mmc;
1206 	int ret;
1207 
1208 	/* must have platform data */
1209 	if (!plat) {
1210 		ret = -EINVAL;
1211 		goto out;
1212 	}
1213 
1214 	ret = amba_request_regions(dev, DRIVER_NAME);
1215 	if (ret)
1216 		goto out;
1217 
1218 	mmc = mmc_alloc_host(sizeof(struct mmci_host), &dev->dev);
1219 	if (!mmc) {
1220 		ret = -ENOMEM;
1221 		goto rel_regions;
1222 	}
1223 
1224 	host = mmc_priv(mmc);
1225 	host->mmc = mmc;
1226 
1227 	host->gpio_wp = -ENOSYS;
1228 	host->gpio_cd = -ENOSYS;
1229 	host->gpio_cd_irq = -1;
1230 
1231 	host->hw_designer = amba_manf(dev);
1232 	host->hw_revision = amba_rev(dev);
1233 	dev_dbg(mmc_dev(mmc), "designer ID = 0x%02x\n", host->hw_designer);
1234 	dev_dbg(mmc_dev(mmc), "revision = 0x%01x\n", host->hw_revision);
1235 
1236 	host->clk = clk_get(&dev->dev, NULL);
1237 	if (IS_ERR(host->clk)) {
1238 		ret = PTR_ERR(host->clk);
1239 		host->clk = NULL;
1240 		goto host_free;
1241 	}
1242 
1243 	ret = clk_prepare(host->clk);
1244 	if (ret)
1245 		goto clk_free;
1246 
1247 	ret = clk_enable(host->clk);
1248 	if (ret)
1249 		goto clk_unprep;
1250 
1251 	host->plat = plat;
1252 	host->variant = variant;
1253 	host->mclk = clk_get_rate(host->clk);
1254 	/*
1255 	 * According to the spec, mclk is max 100 MHz,
1256 	 * so we try to adjust the clock down to this,
1257 	 * (if possible).
1258 	 */
1259 	if (host->mclk > 100000000) {
1260 		ret = clk_set_rate(host->clk, 100000000);
1261 		if (ret < 0)
1262 			goto clk_disable;
1263 		host->mclk = clk_get_rate(host->clk);
1264 		dev_dbg(mmc_dev(mmc), "eventual mclk rate: %u Hz\n",
1265 			host->mclk);
1266 	}
1267 	host->phybase = dev->res.start;
1268 	host->base = ioremap(dev->res.start, resource_size(&dev->res));
1269 	if (!host->base) {
1270 		ret = -ENOMEM;
1271 		goto clk_disable;
1272 	}
1273 
1274 	mmc->ops = &mmci_ops;
1275 	/*
1276 	 * The ARM and ST versions of the block have slightly different
1277 	 * clock divider equations which means that the minimum divider
1278 	 * differs too.
1279 	 */
1280 	if (variant->st_clkdiv)
1281 		mmc->f_min = DIV_ROUND_UP(host->mclk, 257);
1282 	else
1283 		mmc->f_min = DIV_ROUND_UP(host->mclk, 512);
1284 	/*
1285 	 * If the platform data supplies a maximum operating
1286 	 * frequency, this takes precedence. Else, we fall back
1287 	 * to using the module parameter, which has a (low)
1288 	 * default value in case it is not specified. Either
1289 	 * value must not exceed the clock rate into the block,
1290 	 * of course.
1291 	 */
1292 	if (plat->f_max)
1293 		mmc->f_max = min(host->mclk, plat->f_max);
1294 	else
1295 		mmc->f_max = min(host->mclk, fmax);
1296 	dev_dbg(mmc_dev(mmc), "clocking block at %u Hz\n", mmc->f_max);
1297 
1298 #ifdef CONFIG_REGULATOR
1299 	/* If we're using the regulator framework, try to fetch a regulator */
1300 	host->vcc = regulator_get(&dev->dev, "vmmc");
1301 	if (IS_ERR(host->vcc))
1302 		host->vcc = NULL;
1303 	else {
1304 		int mask = mmc_regulator_get_ocrmask(host->vcc);
1305 
1306 		if (mask < 0)
1307 			dev_err(&dev->dev, "error getting OCR mask (%d)\n",
1308 				mask);
1309 		else {
1310 			host->mmc->ocr_avail = (u32) mask;
1311 			if (plat->ocr_mask)
1312 				dev_warn(&dev->dev,
1313 				 "Provided ocr_mask/setpower will not be used "
1314 				 "(using regulator instead)\n");
1315 		}
1316 	}
1317 #endif
1318 	/* Fall back to platform data if no regulator is found */
1319 	if (host->vcc == NULL)
1320 		mmc->ocr_avail = plat->ocr_mask;
1321 	mmc->caps = plat->capabilities;
1322 	mmc->caps2 = plat->capabilities2;
1323 
1324 	/*
1325 	 * We can do SGIO
1326 	 */
1327 	mmc->max_segs = NR_SG;
1328 
1329 	/*
1330 	 * Since only a certain number of bits are valid in the data length
1331 	 * register, we must ensure that we don't exceed 2^num-1 bytes in a
1332 	 * single request.
1333 	 */
1334 	mmc->max_req_size = (1 << variant->datalength_bits) - 1;
1335 
1336 	/*
1337 	 * Set the maximum segment size.  Since we aren't doing DMA
1338 	 * (yet) we are only limited by the data length register.
1339 	 */
1340 	mmc->max_seg_size = mmc->max_req_size;
1341 
1342 	/*
1343 	 * Block size can be up to 2048 bytes, but must be a power of two.
1344 	 */
1345 	mmc->max_blk_size = 1 << 11;
1346 
1347 	/*
1348 	 * Limit the number of blocks transferred so that we don't overflow
1349 	 * the maximum request size.
1350 	 */
1351 	mmc->max_blk_count = mmc->max_req_size >> 11;
1352 
1353 	spin_lock_init(&host->lock);
1354 
1355 	writel(0, host->base + MMCIMASK0);
1356 	writel(0, host->base + MMCIMASK1);
1357 	writel(0xfff, host->base + MMCICLEAR);
1358 
1359 	if (gpio_is_valid(plat->gpio_cd)) {
1360 		ret = gpio_request(plat->gpio_cd, DRIVER_NAME " (cd)");
1361 		if (ret == 0)
1362 			ret = gpio_direction_input(plat->gpio_cd);
1363 		if (ret == 0)
1364 			host->gpio_cd = plat->gpio_cd;
1365 		else if (ret != -ENOSYS)
1366 			goto err_gpio_cd;
1367 
1368 		/*
1369 		 * A gpio pin that will detect cards when inserted and removed
1370 		 * will most likely want to trigger on the edges if it is
1371 		 * 0 when ejected and 1 when inserted (or mutatis mutandis
1372 		 * for the inverted case) so we request triggers on both
1373 		 * edges.
1374 		 */
1375 		ret = request_any_context_irq(gpio_to_irq(plat->gpio_cd),
1376 				mmci_cd_irq,
1377 				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
1378 				DRIVER_NAME " (cd)", host);
1379 		if (ret >= 0)
1380 			host->gpio_cd_irq = gpio_to_irq(plat->gpio_cd);
1381 	}
1382 	if (gpio_is_valid(plat->gpio_wp)) {
1383 		ret = gpio_request(plat->gpio_wp, DRIVER_NAME " (wp)");
1384 		if (ret == 0)
1385 			ret = gpio_direction_input(plat->gpio_wp);
1386 		if (ret == 0)
1387 			host->gpio_wp = plat->gpio_wp;
1388 		else if (ret != -ENOSYS)
1389 			goto err_gpio_wp;
1390 	}
1391 
1392 	if ((host->plat->status || host->gpio_cd != -ENOSYS)
1393 	    && host->gpio_cd_irq < 0)
1394 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1395 
1396 	ret = request_irq(dev->irq[0], mmci_irq, IRQF_SHARED, DRIVER_NAME " (cmd)", host);
1397 	if (ret)
1398 		goto unmap;
1399 
1400 	if (dev->irq[1] == NO_IRQ || !dev->irq[1])
1401 		host->singleirq = true;
1402 	else {
1403 		ret = request_irq(dev->irq[1], mmci_pio_irq, IRQF_SHARED,
1404 				  DRIVER_NAME " (pio)", host);
1405 		if (ret)
1406 			goto irq0_free;
1407 	}
1408 
1409 	writel(MCI_IRQENABLE, host->base + MMCIMASK0);
1410 
1411 	amba_set_drvdata(dev, mmc);
1412 
1413 	dev_info(&dev->dev, "%s: PL%03x manf %x rev%u at 0x%08llx irq %d,%d (pio)\n",
1414 		 mmc_hostname(mmc), amba_part(dev), amba_manf(dev),
1415 		 amba_rev(dev), (unsigned long long)dev->res.start,
1416 		 dev->irq[0], dev->irq[1]);
1417 
1418 	mmci_dma_setup(host);
1419 
1420 	pm_runtime_set_autosuspend_delay(&dev->dev, 50);
1421 	pm_runtime_use_autosuspend(&dev->dev);
1422 	pm_runtime_put(&dev->dev);
1423 
1424 	mmc_add_host(mmc);
1425 
1426 	return 0;
1427 
1428  irq0_free:
1429 	free_irq(dev->irq[0], host);
1430  unmap:
1431 	if (host->gpio_wp != -ENOSYS)
1432 		gpio_free(host->gpio_wp);
1433  err_gpio_wp:
1434 	if (host->gpio_cd_irq >= 0)
1435 		free_irq(host->gpio_cd_irq, host);
1436 	if (host->gpio_cd != -ENOSYS)
1437 		gpio_free(host->gpio_cd);
1438  err_gpio_cd:
1439 	iounmap(host->base);
1440  clk_disable:
1441 	clk_disable(host->clk);
1442  clk_unprep:
1443 	clk_unprepare(host->clk);
1444  clk_free:
1445 	clk_put(host->clk);
1446  host_free:
1447 	mmc_free_host(mmc);
1448  rel_regions:
1449 	amba_release_regions(dev);
1450  out:
1451 	return ret;
1452 }
1453 
1454 static int __devexit mmci_remove(struct amba_device *dev)
1455 {
1456 	struct mmc_host *mmc = amba_get_drvdata(dev);
1457 
1458 	amba_set_drvdata(dev, NULL);
1459 
1460 	if (mmc) {
1461 		struct mmci_host *host = mmc_priv(mmc);
1462 
1463 		/*
1464 		 * Undo pm_runtime_put() in probe.  We use the _sync
1465 		 * version here so that we can access the primecell.
1466 		 */
1467 		pm_runtime_get_sync(&dev->dev);
1468 
1469 		mmc_remove_host(mmc);
1470 
1471 		writel(0, host->base + MMCIMASK0);
1472 		writel(0, host->base + MMCIMASK1);
1473 
1474 		writel(0, host->base + MMCICOMMAND);
1475 		writel(0, host->base + MMCIDATACTRL);
1476 
1477 		mmci_dma_release(host);
1478 		free_irq(dev->irq[0], host);
1479 		if (!host->singleirq)
1480 			free_irq(dev->irq[1], host);
1481 
1482 		if (host->gpio_wp != -ENOSYS)
1483 			gpio_free(host->gpio_wp);
1484 		if (host->gpio_cd_irq >= 0)
1485 			free_irq(host->gpio_cd_irq, host);
1486 		if (host->gpio_cd != -ENOSYS)
1487 			gpio_free(host->gpio_cd);
1488 
1489 		iounmap(host->base);
1490 		clk_disable(host->clk);
1491 		clk_unprepare(host->clk);
1492 		clk_put(host->clk);
1493 
1494 		if (host->vcc)
1495 			mmc_regulator_set_ocr(mmc, host->vcc, 0);
1496 		regulator_put(host->vcc);
1497 
1498 		mmc_free_host(mmc);
1499 
1500 		amba_release_regions(dev);
1501 	}
1502 
1503 	return 0;
1504 }
1505 
1506 #ifdef CONFIG_SUSPEND
1507 static int mmci_suspend(struct device *dev)
1508 {
1509 	struct amba_device *adev = to_amba_device(dev);
1510 	struct mmc_host *mmc = amba_get_drvdata(adev);
1511 	int ret = 0;
1512 
1513 	if (mmc) {
1514 		struct mmci_host *host = mmc_priv(mmc);
1515 
1516 		ret = mmc_suspend_host(mmc);
1517 		if (ret == 0) {
1518 			pm_runtime_get_sync(dev);
1519 			writel(0, host->base + MMCIMASK0);
1520 		}
1521 	}
1522 
1523 	return ret;
1524 }
1525 
1526 static int mmci_resume(struct device *dev)
1527 {
1528 	struct amba_device *adev = to_amba_device(dev);
1529 	struct mmc_host *mmc = amba_get_drvdata(adev);
1530 	int ret = 0;
1531 
1532 	if (mmc) {
1533 		struct mmci_host *host = mmc_priv(mmc);
1534 
1535 		writel(MCI_IRQENABLE, host->base + MMCIMASK0);
1536 		pm_runtime_put(dev);
1537 
1538 		ret = mmc_resume_host(mmc);
1539 	}
1540 
1541 	return ret;
1542 }
1543 #endif
1544 
1545 static const struct dev_pm_ops mmci_dev_pm_ops = {
1546 	SET_SYSTEM_SLEEP_PM_OPS(mmci_suspend, mmci_resume)
1547 };
1548 
1549 static struct amba_id mmci_ids[] = {
1550 	{
1551 		.id	= 0x00041180,
1552 		.mask	= 0xff0fffff,
1553 		.data	= &variant_arm,
1554 	},
1555 	{
1556 		.id	= 0x01041180,
1557 		.mask	= 0xff0fffff,
1558 		.data	= &variant_arm_extended_fifo,
1559 	},
1560 	{
1561 		.id	= 0x00041181,
1562 		.mask	= 0x000fffff,
1563 		.data	= &variant_arm,
1564 	},
1565 	/* ST Micro variants */
1566 	{
1567 		.id     = 0x00180180,
1568 		.mask   = 0x00ffffff,
1569 		.data	= &variant_u300,
1570 	},
1571 	{
1572 		.id     = 0x00280180,
1573 		.mask   = 0x00ffffff,
1574 		.data	= &variant_u300,
1575 	},
1576 	{
1577 		.id     = 0x00480180,
1578 		.mask   = 0xf0ffffff,
1579 		.data	= &variant_ux500,
1580 	},
1581 	{
1582 		.id     = 0x10480180,
1583 		.mask   = 0xf0ffffff,
1584 		.data	= &variant_ux500v2,
1585 	},
1586 	{ 0, 0 },
1587 };
1588 
1589 MODULE_DEVICE_TABLE(amba, mmci_ids);
1590 
1591 static struct amba_driver mmci_driver = {
1592 	.drv		= {
1593 		.name	= DRIVER_NAME,
1594 		.pm	= &mmci_dev_pm_ops,
1595 	},
1596 	.probe		= mmci_probe,
1597 	.remove		= __devexit_p(mmci_remove),
1598 	.id_table	= mmci_ids,
1599 };
1600 
1601 module_amba_driver(mmci_driver);
1602 
1603 module_param(fmax, uint, 0444);
1604 
1605 MODULE_DESCRIPTION("ARM PrimeCell PL180/181 Multimedia Card Interface driver");
1606 MODULE_LICENSE("GPL");
1607