xref: /openbmc/linux/drivers/mmc/host/mmci.c (revision 34fd4213)
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_nomadik = {
98 	.fifosize		= 16 * 4,
99 	.fifohalfsize		= 8 * 4,
100 	.clkreg			= MCI_CLK_ENABLE,
101 	.datalength_bits	= 24,
102 	.sdio			= true,
103 	.st_clkdiv		= true,
104 	.pwrreg_powerup		= MCI_PWR_ON,
105 	.signal_direction	= true,
106 };
107 
108 static struct variant_data variant_ux500 = {
109 	.fifosize		= 30 * 4,
110 	.fifohalfsize		= 8 * 4,
111 	.clkreg			= MCI_CLK_ENABLE,
112 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
113 	.datalength_bits	= 24,
114 	.sdio			= true,
115 	.st_clkdiv		= true,
116 	.pwrreg_powerup		= MCI_PWR_ON,
117 	.signal_direction	= true,
118 };
119 
120 static struct variant_data variant_ux500v2 = {
121 	.fifosize		= 30 * 4,
122 	.fifohalfsize		= 8 * 4,
123 	.clkreg			= MCI_CLK_ENABLE,
124 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
125 	.datalength_bits	= 24,
126 	.sdio			= true,
127 	.st_clkdiv		= true,
128 	.blksz_datactrl16	= true,
129 	.pwrreg_powerup		= MCI_PWR_ON,
130 	.signal_direction	= true,
131 };
132 
133 /*
134  * This must be called with host->lock held
135  */
136 static void mmci_write_clkreg(struct mmci_host *host, u32 clk)
137 {
138 	if (host->clk_reg != clk) {
139 		host->clk_reg = clk;
140 		writel(clk, host->base + MMCICLOCK);
141 	}
142 }
143 
144 /*
145  * This must be called with host->lock held
146  */
147 static void mmci_write_pwrreg(struct mmci_host *host, u32 pwr)
148 {
149 	if (host->pwr_reg != pwr) {
150 		host->pwr_reg = pwr;
151 		writel(pwr, host->base + MMCIPOWER);
152 	}
153 }
154 
155 /*
156  * This must be called with host->lock held
157  */
158 static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
159 {
160 	struct variant_data *variant = host->variant;
161 	u32 clk = variant->clkreg;
162 
163 	if (desired) {
164 		if (desired >= host->mclk) {
165 			clk = MCI_CLK_BYPASS;
166 			if (variant->st_clkdiv)
167 				clk |= MCI_ST_UX500_NEG_EDGE;
168 			host->cclk = host->mclk;
169 		} else if (variant->st_clkdiv) {
170 			/*
171 			 * DB8500 TRM says f = mclk / (clkdiv + 2)
172 			 * => clkdiv = (mclk / f) - 2
173 			 * Round the divider up so we don't exceed the max
174 			 * frequency
175 			 */
176 			clk = DIV_ROUND_UP(host->mclk, desired) - 2;
177 			if (clk >= 256)
178 				clk = 255;
179 			host->cclk = host->mclk / (clk + 2);
180 		} else {
181 			/*
182 			 * PL180 TRM says f = mclk / (2 * (clkdiv + 1))
183 			 * => clkdiv = mclk / (2 * f) - 1
184 			 */
185 			clk = host->mclk / (2 * desired) - 1;
186 			if (clk >= 256)
187 				clk = 255;
188 			host->cclk = host->mclk / (2 * (clk + 1));
189 		}
190 
191 		clk |= variant->clkreg_enable;
192 		clk |= MCI_CLK_ENABLE;
193 		/* This hasn't proven to be worthwhile */
194 		/* clk |= MCI_CLK_PWRSAVE; */
195 	}
196 
197 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
198 		clk |= MCI_4BIT_BUS;
199 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
200 		clk |= MCI_ST_8BIT_BUS;
201 
202 	mmci_write_clkreg(host, clk);
203 }
204 
205 static void
206 mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
207 {
208 	writel(0, host->base + MMCICOMMAND);
209 
210 	BUG_ON(host->data);
211 
212 	host->mrq = NULL;
213 	host->cmd = NULL;
214 
215 	mmc_request_done(host->mmc, mrq);
216 
217 	pm_runtime_mark_last_busy(mmc_dev(host->mmc));
218 	pm_runtime_put_autosuspend(mmc_dev(host->mmc));
219 }
220 
221 static void mmci_set_mask1(struct mmci_host *host, unsigned int mask)
222 {
223 	void __iomem *base = host->base;
224 
225 	if (host->singleirq) {
226 		unsigned int mask0 = readl(base + MMCIMASK0);
227 
228 		mask0 &= ~MCI_IRQ1MASK;
229 		mask0 |= mask;
230 
231 		writel(mask0, base + MMCIMASK0);
232 	}
233 
234 	writel(mask, base + MMCIMASK1);
235 }
236 
237 static void mmci_stop_data(struct mmci_host *host)
238 {
239 	writel(0, host->base + MMCIDATACTRL);
240 	mmci_set_mask1(host, 0);
241 	host->data = NULL;
242 }
243 
244 static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
245 {
246 	unsigned int flags = SG_MITER_ATOMIC;
247 
248 	if (data->flags & MMC_DATA_READ)
249 		flags |= SG_MITER_TO_SG;
250 	else
251 		flags |= SG_MITER_FROM_SG;
252 
253 	sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
254 }
255 
256 /*
257  * All the DMA operation mode stuff goes inside this ifdef.
258  * This assumes that you have a generic DMA device interface,
259  * no custom DMA interfaces are supported.
260  */
261 #ifdef CONFIG_DMA_ENGINE
262 static void __devinit mmci_dma_setup(struct mmci_host *host)
263 {
264 	struct mmci_platform_data *plat = host->plat;
265 	const char *rxname, *txname;
266 	dma_cap_mask_t mask;
267 
268 	if (!plat || !plat->dma_filter) {
269 		dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
270 		return;
271 	}
272 
273 	/* initialize pre request cookie */
274 	host->next_data.cookie = 1;
275 
276 	/* Try to acquire a generic DMA engine slave channel */
277 	dma_cap_zero(mask);
278 	dma_cap_set(DMA_SLAVE, mask);
279 
280 	/*
281 	 * If only an RX channel is specified, the driver will
282 	 * attempt to use it bidirectionally, however if it is
283 	 * is specified but cannot be located, DMA will be disabled.
284 	 */
285 	if (plat->dma_rx_param) {
286 		host->dma_rx_channel = dma_request_channel(mask,
287 							   plat->dma_filter,
288 							   plat->dma_rx_param);
289 		/* E.g if no DMA hardware is present */
290 		if (!host->dma_rx_channel)
291 			dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
292 	}
293 
294 	if (plat->dma_tx_param) {
295 		host->dma_tx_channel = dma_request_channel(mask,
296 							   plat->dma_filter,
297 							   plat->dma_tx_param);
298 		if (!host->dma_tx_channel)
299 			dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
300 	} else {
301 		host->dma_tx_channel = host->dma_rx_channel;
302 	}
303 
304 	if (host->dma_rx_channel)
305 		rxname = dma_chan_name(host->dma_rx_channel);
306 	else
307 		rxname = "none";
308 
309 	if (host->dma_tx_channel)
310 		txname = dma_chan_name(host->dma_tx_channel);
311 	else
312 		txname = "none";
313 
314 	dev_info(mmc_dev(host->mmc), "DMA channels RX %s, TX %s\n",
315 		 rxname, txname);
316 
317 	/*
318 	 * Limit the maximum segment size in any SG entry according to
319 	 * the parameters of the DMA engine device.
320 	 */
321 	if (host->dma_tx_channel) {
322 		struct device *dev = host->dma_tx_channel->device->dev;
323 		unsigned int max_seg_size = dma_get_max_seg_size(dev);
324 
325 		if (max_seg_size < host->mmc->max_seg_size)
326 			host->mmc->max_seg_size = max_seg_size;
327 	}
328 	if (host->dma_rx_channel) {
329 		struct device *dev = host->dma_rx_channel->device->dev;
330 		unsigned int max_seg_size = dma_get_max_seg_size(dev);
331 
332 		if (max_seg_size < host->mmc->max_seg_size)
333 			host->mmc->max_seg_size = max_seg_size;
334 	}
335 }
336 
337 /*
338  * This is used in __devinit or __devexit so inline it
339  * so it can be discarded.
340  */
341 static inline void mmci_dma_release(struct mmci_host *host)
342 {
343 	struct mmci_platform_data *plat = host->plat;
344 
345 	if (host->dma_rx_channel)
346 		dma_release_channel(host->dma_rx_channel);
347 	if (host->dma_tx_channel && plat->dma_tx_param)
348 		dma_release_channel(host->dma_tx_channel);
349 	host->dma_rx_channel = host->dma_tx_channel = NULL;
350 }
351 
352 static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
353 {
354 	struct dma_chan *chan = host->dma_current;
355 	enum dma_data_direction dir;
356 	u32 status;
357 	int i;
358 
359 	/* Wait up to 1ms for the DMA to complete */
360 	for (i = 0; ; i++) {
361 		status = readl(host->base + MMCISTATUS);
362 		if (!(status & MCI_RXDATAAVLBLMASK) || i >= 100)
363 			break;
364 		udelay(10);
365 	}
366 
367 	/*
368 	 * Check to see whether we still have some data left in the FIFO -
369 	 * this catches DMA controllers which are unable to monitor the
370 	 * DMALBREQ and DMALSREQ signals while allowing us to DMA to non-
371 	 * contiguous buffers.  On TX, we'll get a FIFO underrun error.
372 	 */
373 	if (status & MCI_RXDATAAVLBLMASK) {
374 		dmaengine_terminate_all(chan);
375 		if (!data->error)
376 			data->error = -EIO;
377 	}
378 
379 	if (data->flags & MMC_DATA_WRITE) {
380 		dir = DMA_TO_DEVICE;
381 	} else {
382 		dir = DMA_FROM_DEVICE;
383 	}
384 
385 	if (!data->host_cookie)
386 		dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
387 
388 	/*
389 	 * Use of DMA with scatter-gather is impossible.
390 	 * Give up with DMA and switch back to PIO mode.
391 	 */
392 	if (status & MCI_RXDATAAVLBLMASK) {
393 		dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
394 		mmci_dma_release(host);
395 	}
396 }
397 
398 static void mmci_dma_data_error(struct mmci_host *host)
399 {
400 	dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
401 	dmaengine_terminate_all(host->dma_current);
402 }
403 
404 static int mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
405 			      struct mmci_host_next *next)
406 {
407 	struct variant_data *variant = host->variant;
408 	struct dma_slave_config conf = {
409 		.src_addr = host->phybase + MMCIFIFO,
410 		.dst_addr = host->phybase + MMCIFIFO,
411 		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
412 		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
413 		.src_maxburst = variant->fifohalfsize >> 2, /* # of words */
414 		.dst_maxburst = variant->fifohalfsize >> 2, /* # of words */
415 		.device_fc = false,
416 	};
417 	struct dma_chan *chan;
418 	struct dma_device *device;
419 	struct dma_async_tx_descriptor *desc;
420 	enum dma_data_direction buffer_dirn;
421 	int nr_sg;
422 
423 	/* Check if next job is already prepared */
424 	if (data->host_cookie && !next &&
425 	    host->dma_current && host->dma_desc_current)
426 		return 0;
427 
428 	if (!next) {
429 		host->dma_current = NULL;
430 		host->dma_desc_current = NULL;
431 	}
432 
433 	if (data->flags & MMC_DATA_READ) {
434 		conf.direction = DMA_DEV_TO_MEM;
435 		buffer_dirn = DMA_FROM_DEVICE;
436 		chan = host->dma_rx_channel;
437 	} else {
438 		conf.direction = DMA_MEM_TO_DEV;
439 		buffer_dirn = DMA_TO_DEVICE;
440 		chan = host->dma_tx_channel;
441 	}
442 
443 	/* If there's no DMA channel, fall back to PIO */
444 	if (!chan)
445 		return -EINVAL;
446 
447 	/* If less than or equal to the fifo size, don't bother with DMA */
448 	if (data->blksz * data->blocks <= variant->fifosize)
449 		return -EINVAL;
450 
451 	device = chan->device;
452 	nr_sg = dma_map_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
453 	if (nr_sg == 0)
454 		return -EINVAL;
455 
456 	dmaengine_slave_config(chan, &conf);
457 	desc = dmaengine_prep_slave_sg(chan, data->sg, nr_sg,
458 					    conf.direction, DMA_CTRL_ACK);
459 	if (!desc)
460 		goto unmap_exit;
461 
462 	if (next) {
463 		next->dma_chan = chan;
464 		next->dma_desc = desc;
465 	} else {
466 		host->dma_current = chan;
467 		host->dma_desc_current = desc;
468 	}
469 
470 	return 0;
471 
472  unmap_exit:
473 	if (!next)
474 		dmaengine_terminate_all(chan);
475 	dma_unmap_sg(device->dev, data->sg, data->sg_len, buffer_dirn);
476 	return -ENOMEM;
477 }
478 
479 static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
480 {
481 	int ret;
482 	struct mmc_data *data = host->data;
483 
484 	ret = mmci_dma_prep_data(host, host->data, NULL);
485 	if (ret)
486 		return ret;
487 
488 	/* Okay, go for it. */
489 	dev_vdbg(mmc_dev(host->mmc),
490 		 "Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
491 		 data->sg_len, data->blksz, data->blocks, data->flags);
492 	dmaengine_submit(host->dma_desc_current);
493 	dma_async_issue_pending(host->dma_current);
494 
495 	datactrl |= MCI_DPSM_DMAENABLE;
496 
497 	/* Trigger the DMA transfer */
498 	writel(datactrl, host->base + MMCIDATACTRL);
499 
500 	/*
501 	 * Let the MMCI say when the data is ended and it's time
502 	 * to fire next DMA request. When that happens, MMCI will
503 	 * call mmci_data_end()
504 	 */
505 	writel(readl(host->base + MMCIMASK0) | MCI_DATAENDMASK,
506 	       host->base + MMCIMASK0);
507 	return 0;
508 }
509 
510 static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
511 {
512 	struct mmci_host_next *next = &host->next_data;
513 
514 	if (data->host_cookie && data->host_cookie != next->cookie) {
515 		pr_warning("[%s] invalid cookie: data->host_cookie %d"
516 		       " host->next_data.cookie %d\n",
517 		       __func__, data->host_cookie, host->next_data.cookie);
518 		data->host_cookie = 0;
519 	}
520 
521 	if (!data->host_cookie)
522 		return;
523 
524 	host->dma_desc_current = next->dma_desc;
525 	host->dma_current = next->dma_chan;
526 
527 	next->dma_desc = NULL;
528 	next->dma_chan = NULL;
529 }
530 
531 static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq,
532 			     bool is_first_req)
533 {
534 	struct mmci_host *host = mmc_priv(mmc);
535 	struct mmc_data *data = mrq->data;
536 	struct mmci_host_next *nd = &host->next_data;
537 
538 	if (!data)
539 		return;
540 
541 	if (data->host_cookie) {
542 		data->host_cookie = 0;
543 		return;
544 	}
545 
546 	/* if config for dma */
547 	if (((data->flags & MMC_DATA_WRITE) && host->dma_tx_channel) ||
548 	    ((data->flags & MMC_DATA_READ) && host->dma_rx_channel)) {
549 		if (mmci_dma_prep_data(host, data, nd))
550 			data->host_cookie = 0;
551 		else
552 			data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
553 	}
554 }
555 
556 static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
557 			      int err)
558 {
559 	struct mmci_host *host = mmc_priv(mmc);
560 	struct mmc_data *data = mrq->data;
561 	struct dma_chan *chan;
562 	enum dma_data_direction dir;
563 
564 	if (!data)
565 		return;
566 
567 	if (data->flags & MMC_DATA_READ) {
568 		dir = DMA_FROM_DEVICE;
569 		chan = host->dma_rx_channel;
570 	} else {
571 		dir = DMA_TO_DEVICE;
572 		chan = host->dma_tx_channel;
573 	}
574 
575 
576 	/* if config for dma */
577 	if (chan) {
578 		if (err)
579 			dmaengine_terminate_all(chan);
580 		if (data->host_cookie)
581 			dma_unmap_sg(mmc_dev(host->mmc), data->sg,
582 				     data->sg_len, dir);
583 		mrq->data->host_cookie = 0;
584 	}
585 }
586 
587 #else
588 /* Blank functions if the DMA engine is not available */
589 static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
590 {
591 }
592 static inline void mmci_dma_setup(struct mmci_host *host)
593 {
594 }
595 
596 static inline void mmci_dma_release(struct mmci_host *host)
597 {
598 }
599 
600 static inline void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
601 {
602 }
603 
604 static inline void mmci_dma_data_error(struct mmci_host *host)
605 {
606 }
607 
608 static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
609 {
610 	return -ENOSYS;
611 }
612 
613 #define mmci_pre_request NULL
614 #define mmci_post_request NULL
615 
616 #endif
617 
618 static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
619 {
620 	struct variant_data *variant = host->variant;
621 	unsigned int datactrl, timeout, irqmask;
622 	unsigned long long clks;
623 	void __iomem *base;
624 	int blksz_bits;
625 
626 	dev_dbg(mmc_dev(host->mmc), "blksz %04x blks %04x flags %08x\n",
627 		data->blksz, data->blocks, data->flags);
628 
629 	host->data = data;
630 	host->size = data->blksz * data->blocks;
631 	data->bytes_xfered = 0;
632 
633 	clks = (unsigned long long)data->timeout_ns * host->cclk;
634 	do_div(clks, 1000000000UL);
635 
636 	timeout = data->timeout_clks + (unsigned int)clks;
637 
638 	base = host->base;
639 	writel(timeout, base + MMCIDATATIMER);
640 	writel(host->size, base + MMCIDATALENGTH);
641 
642 	blksz_bits = ffs(data->blksz) - 1;
643 	BUG_ON(1 << blksz_bits != data->blksz);
644 
645 	if (variant->blksz_datactrl16)
646 		datactrl = MCI_DPSM_ENABLE | (data->blksz << 16);
647 	else
648 		datactrl = MCI_DPSM_ENABLE | blksz_bits << 4;
649 
650 	if (data->flags & MMC_DATA_READ)
651 		datactrl |= MCI_DPSM_DIRECTION;
652 
653 	/* The ST Micro variants has a special bit to enable SDIO */
654 	if (variant->sdio && host->mmc->card)
655 		if (mmc_card_sdio(host->mmc->card))
656 			datactrl |= MCI_ST_DPSM_SDIOEN;
657 
658 	/*
659 	 * Attempt to use DMA operation mode, if this
660 	 * should fail, fall back to PIO mode
661 	 */
662 	if (!mmci_dma_start_data(host, datactrl))
663 		return;
664 
665 	/* IRQ mode, map the SG list for CPU reading/writing */
666 	mmci_init_sg(host, data);
667 
668 	if (data->flags & MMC_DATA_READ) {
669 		irqmask = MCI_RXFIFOHALFFULLMASK;
670 
671 		/*
672 		 * If we have less than the fifo 'half-full' threshold to
673 		 * transfer, trigger a PIO interrupt as soon as any data
674 		 * is available.
675 		 */
676 		if (host->size < variant->fifohalfsize)
677 			irqmask |= MCI_RXDATAAVLBLMASK;
678 	} else {
679 		/*
680 		 * We don't actually need to include "FIFO empty" here
681 		 * since its implicit in "FIFO half empty".
682 		 */
683 		irqmask = MCI_TXFIFOHALFEMPTYMASK;
684 	}
685 
686 	writel(datactrl, base + MMCIDATACTRL);
687 	writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
688 	mmci_set_mask1(host, irqmask);
689 }
690 
691 static void
692 mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
693 {
694 	void __iomem *base = host->base;
695 
696 	dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
697 	    cmd->opcode, cmd->arg, cmd->flags);
698 
699 	if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
700 		writel(0, base + MMCICOMMAND);
701 		udelay(1);
702 	}
703 
704 	c |= cmd->opcode | MCI_CPSM_ENABLE;
705 	if (cmd->flags & MMC_RSP_PRESENT) {
706 		if (cmd->flags & MMC_RSP_136)
707 			c |= MCI_CPSM_LONGRSP;
708 		c |= MCI_CPSM_RESPONSE;
709 	}
710 	if (/*interrupt*/0)
711 		c |= MCI_CPSM_INTERRUPT;
712 
713 	host->cmd = cmd;
714 
715 	writel(cmd->arg, base + MMCIARGUMENT);
716 	writel(c, base + MMCICOMMAND);
717 }
718 
719 static void
720 mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
721 	      unsigned int status)
722 {
723 	/* First check for errors */
724 	if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_STARTBITERR|
725 		      MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
726 		u32 remain, success;
727 
728 		/* Terminate the DMA transfer */
729 		if (dma_inprogress(host))
730 			mmci_dma_data_error(host);
731 
732 		/*
733 		 * Calculate how far we are into the transfer.  Note that
734 		 * the data counter gives the number of bytes transferred
735 		 * on the MMC bus, not on the host side.  On reads, this
736 		 * can be as much as a FIFO-worth of data ahead.  This
737 		 * matters for FIFO overruns only.
738 		 */
739 		remain = readl(host->base + MMCIDATACNT);
740 		success = data->blksz * data->blocks - remain;
741 
742 		dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ, status 0x%08x at 0x%08x\n",
743 			status, success);
744 		if (status & MCI_DATACRCFAIL) {
745 			/* Last block was not successful */
746 			success -= 1;
747 			data->error = -EILSEQ;
748 		} else if (status & MCI_DATATIMEOUT) {
749 			data->error = -ETIMEDOUT;
750 		} else if (status & MCI_STARTBITERR) {
751 			data->error = -ECOMM;
752 		} else if (status & MCI_TXUNDERRUN) {
753 			data->error = -EIO;
754 		} else if (status & MCI_RXOVERRUN) {
755 			if (success > host->variant->fifosize)
756 				success -= host->variant->fifosize;
757 			else
758 				success = 0;
759 			data->error = -EIO;
760 		}
761 		data->bytes_xfered = round_down(success, data->blksz);
762 	}
763 
764 	if (status & MCI_DATABLOCKEND)
765 		dev_err(mmc_dev(host->mmc), "stray MCI_DATABLOCKEND interrupt\n");
766 
767 	if (status & MCI_DATAEND || data->error) {
768 		if (dma_inprogress(host))
769 			mmci_dma_unmap(host, data);
770 		mmci_stop_data(host);
771 
772 		if (!data->error)
773 			/* The error clause is handled above, success! */
774 			data->bytes_xfered = data->blksz * data->blocks;
775 
776 		if (!data->stop) {
777 			mmci_request_end(host, data->mrq);
778 		} else {
779 			mmci_start_command(host, data->stop, 0);
780 		}
781 	}
782 }
783 
784 static void
785 mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
786 	     unsigned int status)
787 {
788 	void __iomem *base = host->base;
789 
790 	host->cmd = NULL;
791 
792 	if (status & MCI_CMDTIMEOUT) {
793 		cmd->error = -ETIMEDOUT;
794 	} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
795 		cmd->error = -EILSEQ;
796 	} else {
797 		cmd->resp[0] = readl(base + MMCIRESPONSE0);
798 		cmd->resp[1] = readl(base + MMCIRESPONSE1);
799 		cmd->resp[2] = readl(base + MMCIRESPONSE2);
800 		cmd->resp[3] = readl(base + MMCIRESPONSE3);
801 	}
802 
803 	if (!cmd->data || cmd->error) {
804 		if (host->data) {
805 			/* Terminate the DMA transfer */
806 			if (dma_inprogress(host))
807 				mmci_dma_data_error(host);
808 			mmci_stop_data(host);
809 		}
810 		mmci_request_end(host, cmd->mrq);
811 	} else if (!(cmd->data->flags & MMC_DATA_READ)) {
812 		mmci_start_data(host, cmd->data);
813 	}
814 }
815 
816 static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain)
817 {
818 	void __iomem *base = host->base;
819 	char *ptr = buffer;
820 	u32 status;
821 	int host_remain = host->size;
822 
823 	do {
824 		int count = host_remain - (readl(base + MMCIFIFOCNT) << 2);
825 
826 		if (count > remain)
827 			count = remain;
828 
829 		if (count <= 0)
830 			break;
831 
832 		/*
833 		 * SDIO especially may want to send something that is
834 		 * not divisible by 4 (as opposed to card sectors
835 		 * etc). Therefore make sure to always read the last bytes
836 		 * while only doing full 32-bit reads towards the FIFO.
837 		 */
838 		if (unlikely(count & 0x3)) {
839 			if (count < 4) {
840 				unsigned char buf[4];
841 				readsl(base + MMCIFIFO, buf, 1);
842 				memcpy(ptr, buf, count);
843 			} else {
844 				readsl(base + MMCIFIFO, ptr, count >> 2);
845 				count &= ~0x3;
846 			}
847 		} else {
848 			readsl(base + MMCIFIFO, ptr, count >> 2);
849 		}
850 
851 		ptr += count;
852 		remain -= count;
853 		host_remain -= count;
854 
855 		if (remain == 0)
856 			break;
857 
858 		status = readl(base + MMCISTATUS);
859 	} while (status & MCI_RXDATAAVLBL);
860 
861 	return ptr - buffer;
862 }
863 
864 static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int remain, u32 status)
865 {
866 	struct variant_data *variant = host->variant;
867 	void __iomem *base = host->base;
868 	char *ptr = buffer;
869 
870 	do {
871 		unsigned int count, maxcnt;
872 
873 		maxcnt = status & MCI_TXFIFOEMPTY ?
874 			 variant->fifosize : variant->fifohalfsize;
875 		count = min(remain, maxcnt);
876 
877 		/*
878 		 * The ST Micro variant for SDIO transfer sizes
879 		 * less then 8 bytes should have clock H/W flow
880 		 * control disabled.
881 		 */
882 		if (variant->sdio &&
883 		    mmc_card_sdio(host->mmc->card)) {
884 			u32 clk;
885 			if (count < 8)
886 				clk = host->clk_reg & ~variant->clkreg_enable;
887 			else
888 				clk = host->clk_reg | variant->clkreg_enable;
889 
890 			mmci_write_clkreg(host, clk);
891 		}
892 
893 		/*
894 		 * SDIO especially may want to send something that is
895 		 * not divisible by 4 (as opposed to card sectors
896 		 * etc), and the FIFO only accept full 32-bit writes.
897 		 * So compensate by adding +3 on the count, a single
898 		 * byte become a 32bit write, 7 bytes will be two
899 		 * 32bit writes etc.
900 		 */
901 		writesl(base + MMCIFIFO, ptr, (count + 3) >> 2);
902 
903 		ptr += count;
904 		remain -= count;
905 
906 		if (remain == 0)
907 			break;
908 
909 		status = readl(base + MMCISTATUS);
910 	} while (status & MCI_TXFIFOHALFEMPTY);
911 
912 	return ptr - buffer;
913 }
914 
915 /*
916  * PIO data transfer IRQ handler.
917  */
918 static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
919 {
920 	struct mmci_host *host = dev_id;
921 	struct sg_mapping_iter *sg_miter = &host->sg_miter;
922 	struct variant_data *variant = host->variant;
923 	void __iomem *base = host->base;
924 	unsigned long flags;
925 	u32 status;
926 
927 	status = readl(base + MMCISTATUS);
928 
929 	dev_dbg(mmc_dev(host->mmc), "irq1 (pio) %08x\n", status);
930 
931 	local_irq_save(flags);
932 
933 	do {
934 		unsigned int remain, len;
935 		char *buffer;
936 
937 		/*
938 		 * For write, we only need to test the half-empty flag
939 		 * here - if the FIFO is completely empty, then by
940 		 * definition it is more than half empty.
941 		 *
942 		 * For read, check for data available.
943 		 */
944 		if (!(status & (MCI_TXFIFOHALFEMPTY|MCI_RXDATAAVLBL)))
945 			break;
946 
947 		if (!sg_miter_next(sg_miter))
948 			break;
949 
950 		buffer = sg_miter->addr;
951 		remain = sg_miter->length;
952 
953 		len = 0;
954 		if (status & MCI_RXACTIVE)
955 			len = mmci_pio_read(host, buffer, remain);
956 		if (status & MCI_TXACTIVE)
957 			len = mmci_pio_write(host, buffer, remain, status);
958 
959 		sg_miter->consumed = len;
960 
961 		host->size -= len;
962 		remain -= len;
963 
964 		if (remain)
965 			break;
966 
967 		status = readl(base + MMCISTATUS);
968 	} while (1);
969 
970 	sg_miter_stop(sg_miter);
971 
972 	local_irq_restore(flags);
973 
974 	/*
975 	 * If we have less than the fifo 'half-full' threshold to transfer,
976 	 * trigger a PIO interrupt as soon as any data is available.
977 	 */
978 	if (status & MCI_RXACTIVE && host->size < variant->fifohalfsize)
979 		mmci_set_mask1(host, MCI_RXDATAAVLBLMASK);
980 
981 	/*
982 	 * If we run out of data, disable the data IRQs; this
983 	 * prevents a race where the FIFO becomes empty before
984 	 * the chip itself has disabled the data path, and
985 	 * stops us racing with our data end IRQ.
986 	 */
987 	if (host->size == 0) {
988 		mmci_set_mask1(host, 0);
989 		writel(readl(base + MMCIMASK0) | MCI_DATAENDMASK, base + MMCIMASK0);
990 	}
991 
992 	return IRQ_HANDLED;
993 }
994 
995 /*
996  * Handle completion of command and data transfers.
997  */
998 static irqreturn_t mmci_irq(int irq, void *dev_id)
999 {
1000 	struct mmci_host *host = dev_id;
1001 	u32 status;
1002 	int ret = 0;
1003 
1004 	spin_lock(&host->lock);
1005 
1006 	do {
1007 		struct mmc_command *cmd;
1008 		struct mmc_data *data;
1009 
1010 		status = readl(host->base + MMCISTATUS);
1011 
1012 		if (host->singleirq) {
1013 			if (status & readl(host->base + MMCIMASK1))
1014 				mmci_pio_irq(irq, dev_id);
1015 
1016 			status &= ~MCI_IRQ1MASK;
1017 		}
1018 
1019 		status &= readl(host->base + MMCIMASK0);
1020 		writel(status, host->base + MMCICLEAR);
1021 
1022 		dev_dbg(mmc_dev(host->mmc), "irq0 (data+cmd) %08x\n", status);
1023 
1024 		data = host->data;
1025 		if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_STARTBITERR|
1026 			      MCI_TXUNDERRUN|MCI_RXOVERRUN|MCI_DATAEND|
1027 			      MCI_DATABLOCKEND) && data)
1028 			mmci_data_irq(host, data, status);
1029 
1030 		cmd = host->cmd;
1031 		if (status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND) && cmd)
1032 			mmci_cmd_irq(host, cmd, status);
1033 
1034 		ret = 1;
1035 	} while (status);
1036 
1037 	spin_unlock(&host->lock);
1038 
1039 	return IRQ_RETVAL(ret);
1040 }
1041 
1042 static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
1043 {
1044 	struct mmci_host *host = mmc_priv(mmc);
1045 	unsigned long flags;
1046 
1047 	WARN_ON(host->mrq != NULL);
1048 
1049 	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
1050 		dev_err(mmc_dev(mmc), "unsupported block size (%d bytes)\n",
1051 			mrq->data->blksz);
1052 		mrq->cmd->error = -EINVAL;
1053 		mmc_request_done(mmc, mrq);
1054 		return;
1055 	}
1056 
1057 	pm_runtime_get_sync(mmc_dev(mmc));
1058 
1059 	spin_lock_irqsave(&host->lock, flags);
1060 
1061 	host->mrq = mrq;
1062 
1063 	if (mrq->data)
1064 		mmci_get_next_data(host, mrq->data);
1065 
1066 	if (mrq->data && mrq->data->flags & MMC_DATA_READ)
1067 		mmci_start_data(host, mrq->data);
1068 
1069 	mmci_start_command(host, mrq->cmd, 0);
1070 
1071 	spin_unlock_irqrestore(&host->lock, flags);
1072 }
1073 
1074 static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1075 {
1076 	struct mmci_host *host = mmc_priv(mmc);
1077 	struct variant_data *variant = host->variant;
1078 	u32 pwr = 0;
1079 	unsigned long flags;
1080 	int ret;
1081 
1082 	pm_runtime_get_sync(mmc_dev(mmc));
1083 
1084 	if (host->plat->ios_handler &&
1085 		host->plat->ios_handler(mmc_dev(mmc), ios))
1086 			dev_err(mmc_dev(mmc), "platform ios_handler failed\n");
1087 
1088 	switch (ios->power_mode) {
1089 	case MMC_POWER_OFF:
1090 		if (host->vcc)
1091 			ret = mmc_regulator_set_ocr(mmc, host->vcc, 0);
1092 		break;
1093 	case MMC_POWER_UP:
1094 		if (host->vcc) {
1095 			ret = mmc_regulator_set_ocr(mmc, host->vcc, ios->vdd);
1096 			if (ret) {
1097 				dev_err(mmc_dev(mmc), "unable to set OCR\n");
1098 				/*
1099 				 * The .set_ios() function in the mmc_host_ops
1100 				 * struct return void, and failing to set the
1101 				 * power should be rare so we print an error
1102 				 * and return here.
1103 				 */
1104 				goto out;
1105 			}
1106 		}
1107 		/*
1108 		 * The ST Micro variant doesn't have the PL180s MCI_PWR_UP
1109 		 * and instead uses MCI_PWR_ON so apply whatever value is
1110 		 * configured in the variant data.
1111 		 */
1112 		pwr |= variant->pwrreg_powerup;
1113 
1114 		break;
1115 	case MMC_POWER_ON:
1116 		pwr |= MCI_PWR_ON;
1117 		break;
1118 	}
1119 
1120 	if (variant->signal_direction && ios->power_mode != MMC_POWER_OFF) {
1121 		/*
1122 		 * The ST Micro variant has some additional bits
1123 		 * indicating signal direction for the signals in
1124 		 * the SD/MMC bus and feedback-clock usage.
1125 		 */
1126 		pwr |= host->plat->sigdir;
1127 
1128 		if (ios->bus_width == MMC_BUS_WIDTH_4)
1129 			pwr &= ~MCI_ST_DATA74DIREN;
1130 		else if (ios->bus_width == MMC_BUS_WIDTH_1)
1131 			pwr &= (~MCI_ST_DATA74DIREN &
1132 				~MCI_ST_DATA31DIREN &
1133 				~MCI_ST_DATA2DIREN);
1134 	}
1135 
1136 	if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
1137 		if (host->hw_designer != AMBA_VENDOR_ST)
1138 			pwr |= MCI_ROD;
1139 		else {
1140 			/*
1141 			 * The ST Micro variant use the ROD bit for something
1142 			 * else and only has OD (Open Drain).
1143 			 */
1144 			pwr |= MCI_OD;
1145 		}
1146 	}
1147 
1148 	spin_lock_irqsave(&host->lock, flags);
1149 
1150 	mmci_set_clkreg(host, ios->clock);
1151 	mmci_write_pwrreg(host, pwr);
1152 
1153 	spin_unlock_irqrestore(&host->lock, flags);
1154 
1155  out:
1156 	pm_runtime_mark_last_busy(mmc_dev(mmc));
1157 	pm_runtime_put_autosuspend(mmc_dev(mmc));
1158 }
1159 
1160 static int mmci_get_ro(struct mmc_host *mmc)
1161 {
1162 	struct mmci_host *host = mmc_priv(mmc);
1163 
1164 	if (host->gpio_wp == -ENOSYS)
1165 		return -ENOSYS;
1166 
1167 	return gpio_get_value_cansleep(host->gpio_wp);
1168 }
1169 
1170 static int mmci_get_cd(struct mmc_host *mmc)
1171 {
1172 	struct mmci_host *host = mmc_priv(mmc);
1173 	struct mmci_platform_data *plat = host->plat;
1174 	unsigned int status;
1175 
1176 	if (host->gpio_cd == -ENOSYS) {
1177 		if (!plat->status)
1178 			return 1; /* Assume always present */
1179 
1180 		status = plat->status(mmc_dev(host->mmc));
1181 	} else
1182 		status = !!gpio_get_value_cansleep(host->gpio_cd)
1183 			^ plat->cd_invert;
1184 
1185 	/*
1186 	 * Use positive logic throughout - status is zero for no card,
1187 	 * non-zero for card inserted.
1188 	 */
1189 	return status;
1190 }
1191 
1192 static irqreturn_t mmci_cd_irq(int irq, void *dev_id)
1193 {
1194 	struct mmci_host *host = dev_id;
1195 
1196 	mmc_detect_change(host->mmc, msecs_to_jiffies(500));
1197 
1198 	return IRQ_HANDLED;
1199 }
1200 
1201 static const struct mmc_host_ops mmci_ops = {
1202 	.request	= mmci_request,
1203 	.pre_req	= mmci_pre_request,
1204 	.post_req	= mmci_post_request,
1205 	.set_ios	= mmci_set_ios,
1206 	.get_ro		= mmci_get_ro,
1207 	.get_cd		= mmci_get_cd,
1208 };
1209 
1210 static int __devinit mmci_probe(struct amba_device *dev,
1211 	const struct amba_id *id)
1212 {
1213 	struct mmci_platform_data *plat = dev->dev.platform_data;
1214 	struct variant_data *variant = id->data;
1215 	struct mmci_host *host;
1216 	struct mmc_host *mmc;
1217 	int ret;
1218 
1219 	/* must have platform data */
1220 	if (!plat) {
1221 		ret = -EINVAL;
1222 		goto out;
1223 	}
1224 
1225 	ret = amba_request_regions(dev, DRIVER_NAME);
1226 	if (ret)
1227 		goto out;
1228 
1229 	mmc = mmc_alloc_host(sizeof(struct mmci_host), &dev->dev);
1230 	if (!mmc) {
1231 		ret = -ENOMEM;
1232 		goto rel_regions;
1233 	}
1234 
1235 	host = mmc_priv(mmc);
1236 	host->mmc = mmc;
1237 
1238 	host->gpio_wp = -ENOSYS;
1239 	host->gpio_cd = -ENOSYS;
1240 	host->gpio_cd_irq = -1;
1241 
1242 	host->hw_designer = amba_manf(dev);
1243 	host->hw_revision = amba_rev(dev);
1244 	dev_dbg(mmc_dev(mmc), "designer ID = 0x%02x\n", host->hw_designer);
1245 	dev_dbg(mmc_dev(mmc), "revision = 0x%01x\n", host->hw_revision);
1246 
1247 	host->clk = clk_get(&dev->dev, NULL);
1248 	if (IS_ERR(host->clk)) {
1249 		ret = PTR_ERR(host->clk);
1250 		host->clk = NULL;
1251 		goto host_free;
1252 	}
1253 
1254 	ret = clk_prepare(host->clk);
1255 	if (ret)
1256 		goto clk_free;
1257 
1258 	ret = clk_enable(host->clk);
1259 	if (ret)
1260 		goto clk_unprep;
1261 
1262 	host->plat = plat;
1263 	host->variant = variant;
1264 	host->mclk = clk_get_rate(host->clk);
1265 	/*
1266 	 * According to the spec, mclk is max 100 MHz,
1267 	 * so we try to adjust the clock down to this,
1268 	 * (if possible).
1269 	 */
1270 	if (host->mclk > 100000000) {
1271 		ret = clk_set_rate(host->clk, 100000000);
1272 		if (ret < 0)
1273 			goto clk_disable;
1274 		host->mclk = clk_get_rate(host->clk);
1275 		dev_dbg(mmc_dev(mmc), "eventual mclk rate: %u Hz\n",
1276 			host->mclk);
1277 	}
1278 	host->phybase = dev->res.start;
1279 	host->base = ioremap(dev->res.start, resource_size(&dev->res));
1280 	if (!host->base) {
1281 		ret = -ENOMEM;
1282 		goto clk_disable;
1283 	}
1284 
1285 	mmc->ops = &mmci_ops;
1286 	/*
1287 	 * The ARM and ST versions of the block have slightly different
1288 	 * clock divider equations which means that the minimum divider
1289 	 * differs too.
1290 	 */
1291 	if (variant->st_clkdiv)
1292 		mmc->f_min = DIV_ROUND_UP(host->mclk, 257);
1293 	else
1294 		mmc->f_min = DIV_ROUND_UP(host->mclk, 512);
1295 	/*
1296 	 * If the platform data supplies a maximum operating
1297 	 * frequency, this takes precedence. Else, we fall back
1298 	 * to using the module parameter, which has a (low)
1299 	 * default value in case it is not specified. Either
1300 	 * value must not exceed the clock rate into the block,
1301 	 * of course.
1302 	 */
1303 	if (plat->f_max)
1304 		mmc->f_max = min(host->mclk, plat->f_max);
1305 	else
1306 		mmc->f_max = min(host->mclk, fmax);
1307 	dev_dbg(mmc_dev(mmc), "clocking block at %u Hz\n", mmc->f_max);
1308 
1309 #ifdef CONFIG_REGULATOR
1310 	/* If we're using the regulator framework, try to fetch a regulator */
1311 	host->vcc = regulator_get(&dev->dev, "vmmc");
1312 	if (IS_ERR(host->vcc))
1313 		host->vcc = NULL;
1314 	else {
1315 		int mask = mmc_regulator_get_ocrmask(host->vcc);
1316 
1317 		if (mask < 0)
1318 			dev_err(&dev->dev, "error getting OCR mask (%d)\n",
1319 				mask);
1320 		else {
1321 			host->mmc->ocr_avail = (u32) mask;
1322 			if (plat->ocr_mask)
1323 				dev_warn(&dev->dev,
1324 				 "Provided ocr_mask/setpower will not be used "
1325 				 "(using regulator instead)\n");
1326 		}
1327 	}
1328 #endif
1329 	/* Fall back to platform data if no regulator is found */
1330 	if (host->vcc == NULL)
1331 		mmc->ocr_avail = plat->ocr_mask;
1332 	mmc->caps = plat->capabilities;
1333 	mmc->caps2 = plat->capabilities2;
1334 
1335 	/*
1336 	 * We can do SGIO
1337 	 */
1338 	mmc->max_segs = NR_SG;
1339 
1340 	/*
1341 	 * Since only a certain number of bits are valid in the data length
1342 	 * register, we must ensure that we don't exceed 2^num-1 bytes in a
1343 	 * single request.
1344 	 */
1345 	mmc->max_req_size = (1 << variant->datalength_bits) - 1;
1346 
1347 	/*
1348 	 * Set the maximum segment size.  Since we aren't doing DMA
1349 	 * (yet) we are only limited by the data length register.
1350 	 */
1351 	mmc->max_seg_size = mmc->max_req_size;
1352 
1353 	/*
1354 	 * Block size can be up to 2048 bytes, but must be a power of two.
1355 	 */
1356 	mmc->max_blk_size = 1 << 11;
1357 
1358 	/*
1359 	 * Limit the number of blocks transferred so that we don't overflow
1360 	 * the maximum request size.
1361 	 */
1362 	mmc->max_blk_count = mmc->max_req_size >> 11;
1363 
1364 	spin_lock_init(&host->lock);
1365 
1366 	writel(0, host->base + MMCIMASK0);
1367 	writel(0, host->base + MMCIMASK1);
1368 	writel(0xfff, host->base + MMCICLEAR);
1369 
1370 	if (gpio_is_valid(plat->gpio_cd)) {
1371 		ret = gpio_request(plat->gpio_cd, DRIVER_NAME " (cd)");
1372 		if (ret == 0)
1373 			ret = gpio_direction_input(plat->gpio_cd);
1374 		if (ret == 0)
1375 			host->gpio_cd = plat->gpio_cd;
1376 		else if (ret != -ENOSYS)
1377 			goto err_gpio_cd;
1378 
1379 		/*
1380 		 * A gpio pin that will detect cards when inserted and removed
1381 		 * will most likely want to trigger on the edges if it is
1382 		 * 0 when ejected and 1 when inserted (or mutatis mutandis
1383 		 * for the inverted case) so we request triggers on both
1384 		 * edges.
1385 		 */
1386 		ret = request_any_context_irq(gpio_to_irq(plat->gpio_cd),
1387 				mmci_cd_irq,
1388 				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
1389 				DRIVER_NAME " (cd)", host);
1390 		if (ret >= 0)
1391 			host->gpio_cd_irq = gpio_to_irq(plat->gpio_cd);
1392 	}
1393 	if (gpio_is_valid(plat->gpio_wp)) {
1394 		ret = gpio_request(plat->gpio_wp, DRIVER_NAME " (wp)");
1395 		if (ret == 0)
1396 			ret = gpio_direction_input(plat->gpio_wp);
1397 		if (ret == 0)
1398 			host->gpio_wp = plat->gpio_wp;
1399 		else if (ret != -ENOSYS)
1400 			goto err_gpio_wp;
1401 	}
1402 
1403 	if ((host->plat->status || host->gpio_cd != -ENOSYS)
1404 	    && host->gpio_cd_irq < 0)
1405 		mmc->caps |= MMC_CAP_NEEDS_POLL;
1406 
1407 	ret = request_irq(dev->irq[0], mmci_irq, IRQF_SHARED, DRIVER_NAME " (cmd)", host);
1408 	if (ret)
1409 		goto unmap;
1410 
1411 	if (dev->irq[1] == NO_IRQ || !dev->irq[1])
1412 		host->singleirq = true;
1413 	else {
1414 		ret = request_irq(dev->irq[1], mmci_pio_irq, IRQF_SHARED,
1415 				  DRIVER_NAME " (pio)", host);
1416 		if (ret)
1417 			goto irq0_free;
1418 	}
1419 
1420 	writel(MCI_IRQENABLE, host->base + MMCIMASK0);
1421 
1422 	amba_set_drvdata(dev, mmc);
1423 
1424 	dev_info(&dev->dev, "%s: PL%03x manf %x rev%u at 0x%08llx irq %d,%d (pio)\n",
1425 		 mmc_hostname(mmc), amba_part(dev), amba_manf(dev),
1426 		 amba_rev(dev), (unsigned long long)dev->res.start,
1427 		 dev->irq[0], dev->irq[1]);
1428 
1429 	mmci_dma_setup(host);
1430 
1431 	pm_runtime_set_autosuspend_delay(&dev->dev, 50);
1432 	pm_runtime_use_autosuspend(&dev->dev);
1433 	pm_runtime_put(&dev->dev);
1434 
1435 	mmc_add_host(mmc);
1436 
1437 	return 0;
1438 
1439  irq0_free:
1440 	free_irq(dev->irq[0], host);
1441  unmap:
1442 	if (host->gpio_wp != -ENOSYS)
1443 		gpio_free(host->gpio_wp);
1444  err_gpio_wp:
1445 	if (host->gpio_cd_irq >= 0)
1446 		free_irq(host->gpio_cd_irq, host);
1447 	if (host->gpio_cd != -ENOSYS)
1448 		gpio_free(host->gpio_cd);
1449  err_gpio_cd:
1450 	iounmap(host->base);
1451  clk_disable:
1452 	clk_disable(host->clk);
1453  clk_unprep:
1454 	clk_unprepare(host->clk);
1455  clk_free:
1456 	clk_put(host->clk);
1457  host_free:
1458 	mmc_free_host(mmc);
1459  rel_regions:
1460 	amba_release_regions(dev);
1461  out:
1462 	return ret;
1463 }
1464 
1465 static int __devexit mmci_remove(struct amba_device *dev)
1466 {
1467 	struct mmc_host *mmc = amba_get_drvdata(dev);
1468 
1469 	amba_set_drvdata(dev, NULL);
1470 
1471 	if (mmc) {
1472 		struct mmci_host *host = mmc_priv(mmc);
1473 
1474 		/*
1475 		 * Undo pm_runtime_put() in probe.  We use the _sync
1476 		 * version here so that we can access the primecell.
1477 		 */
1478 		pm_runtime_get_sync(&dev->dev);
1479 
1480 		mmc_remove_host(mmc);
1481 
1482 		writel(0, host->base + MMCIMASK0);
1483 		writel(0, host->base + MMCIMASK1);
1484 
1485 		writel(0, host->base + MMCICOMMAND);
1486 		writel(0, host->base + MMCIDATACTRL);
1487 
1488 		mmci_dma_release(host);
1489 		free_irq(dev->irq[0], host);
1490 		if (!host->singleirq)
1491 			free_irq(dev->irq[1], host);
1492 
1493 		if (host->gpio_wp != -ENOSYS)
1494 			gpio_free(host->gpio_wp);
1495 		if (host->gpio_cd_irq >= 0)
1496 			free_irq(host->gpio_cd_irq, host);
1497 		if (host->gpio_cd != -ENOSYS)
1498 			gpio_free(host->gpio_cd);
1499 
1500 		iounmap(host->base);
1501 		clk_disable(host->clk);
1502 		clk_unprepare(host->clk);
1503 		clk_put(host->clk);
1504 
1505 		if (host->vcc)
1506 			mmc_regulator_set_ocr(mmc, host->vcc, 0);
1507 		regulator_put(host->vcc);
1508 
1509 		mmc_free_host(mmc);
1510 
1511 		amba_release_regions(dev);
1512 	}
1513 
1514 	return 0;
1515 }
1516 
1517 #ifdef CONFIG_SUSPEND
1518 static int mmci_suspend(struct device *dev)
1519 {
1520 	struct amba_device *adev = to_amba_device(dev);
1521 	struct mmc_host *mmc = amba_get_drvdata(adev);
1522 	int ret = 0;
1523 
1524 	if (mmc) {
1525 		struct mmci_host *host = mmc_priv(mmc);
1526 
1527 		ret = mmc_suspend_host(mmc);
1528 		if (ret == 0) {
1529 			pm_runtime_get_sync(dev);
1530 			writel(0, host->base + MMCIMASK0);
1531 		}
1532 	}
1533 
1534 	return ret;
1535 }
1536 
1537 static int mmci_resume(struct device *dev)
1538 {
1539 	struct amba_device *adev = to_amba_device(dev);
1540 	struct mmc_host *mmc = amba_get_drvdata(adev);
1541 	int ret = 0;
1542 
1543 	if (mmc) {
1544 		struct mmci_host *host = mmc_priv(mmc);
1545 
1546 		writel(MCI_IRQENABLE, host->base + MMCIMASK0);
1547 		pm_runtime_put(dev);
1548 
1549 		ret = mmc_resume_host(mmc);
1550 	}
1551 
1552 	return ret;
1553 }
1554 #endif
1555 
1556 static const struct dev_pm_ops mmci_dev_pm_ops = {
1557 	SET_SYSTEM_SLEEP_PM_OPS(mmci_suspend, mmci_resume)
1558 };
1559 
1560 static struct amba_id mmci_ids[] = {
1561 	{
1562 		.id	= 0x00041180,
1563 		.mask	= 0xff0fffff,
1564 		.data	= &variant_arm,
1565 	},
1566 	{
1567 		.id	= 0x01041180,
1568 		.mask	= 0xff0fffff,
1569 		.data	= &variant_arm_extended_fifo,
1570 	},
1571 	{
1572 		.id	= 0x00041181,
1573 		.mask	= 0x000fffff,
1574 		.data	= &variant_arm,
1575 	},
1576 	/* ST Micro variants */
1577 	{
1578 		.id     = 0x00180180,
1579 		.mask   = 0x00ffffff,
1580 		.data	= &variant_u300,
1581 	},
1582 	{
1583 		.id     = 0x10180180,
1584 		.mask   = 0xf0ffffff,
1585 		.data	= &variant_nomadik,
1586 	},
1587 	{
1588 		.id     = 0x00280180,
1589 		.mask   = 0x00ffffff,
1590 		.data	= &variant_u300,
1591 	},
1592 	{
1593 		.id     = 0x00480180,
1594 		.mask   = 0xf0ffffff,
1595 		.data	= &variant_ux500,
1596 	},
1597 	{
1598 		.id     = 0x10480180,
1599 		.mask   = 0xf0ffffff,
1600 		.data	= &variant_ux500v2,
1601 	},
1602 	{ 0, 0 },
1603 };
1604 
1605 MODULE_DEVICE_TABLE(amba, mmci_ids);
1606 
1607 static struct amba_driver mmci_driver = {
1608 	.drv		= {
1609 		.name	= DRIVER_NAME,
1610 		.pm	= &mmci_dev_pm_ops,
1611 	},
1612 	.probe		= mmci_probe,
1613 	.remove		= __devexit_p(mmci_remove),
1614 	.id_table	= mmci_ids,
1615 };
1616 
1617 module_amba_driver(mmci_driver);
1618 
1619 module_param(fmax, uint, 0444);
1620 
1621 MODULE_DESCRIPTION("ARM PrimeCell PL180/181 Multimedia Card Interface driver");
1622 MODULE_LICENSE("GPL");
1623