davinci_mmc.c revision ca2afb6dbea74ee762ae5856af7045a57a65e9c8
1/*
2 * davinci_mmc.c - TI DaVinci MMC/SD/SDIO driver
3 *
4 * Copyright (C) 2006 Texas Instruments.
5 *       Original author: Purushotam Kumar
6 * Copyright (C) 2009 David Brownell
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23#include <linux/module.h>
24#include <linux/ioport.h>
25#include <linux/platform_device.h>
26#include <linux/clk.h>
27#include <linux/err.h>
28#include <linux/cpufreq.h>
29#include <linux/mmc/host.h>
30#include <linux/io.h>
31#include <linux/irq.h>
32#include <linux/delay.h>
33#include <linux/dma-mapping.h>
34#include <linux/mmc/mmc.h>
35
36#include <mach/mmc.h>
37#include <mach/edma.h>
38
39/*
40 * Register Definitions
41 */
42#define DAVINCI_MMCCTL       0x00 /* Control Register                  */
43#define DAVINCI_MMCCLK       0x04 /* Memory Clock Control Register     */
44#define DAVINCI_MMCST0       0x08 /* Status Register 0                 */
45#define DAVINCI_MMCST1       0x0C /* Status Register 1                 */
46#define DAVINCI_MMCIM        0x10 /* Interrupt Mask Register           */
47#define DAVINCI_MMCTOR       0x14 /* Response Time-Out Register        */
48#define DAVINCI_MMCTOD       0x18 /* Data Read Time-Out Register       */
49#define DAVINCI_MMCBLEN      0x1C /* Block Length Register             */
50#define DAVINCI_MMCNBLK      0x20 /* Number of Blocks Register         */
51#define DAVINCI_MMCNBLC      0x24 /* Number of Blocks Counter Register */
52#define DAVINCI_MMCDRR       0x28 /* Data Receive Register             */
53#define DAVINCI_MMCDXR       0x2C /* Data Transmit Register            */
54#define DAVINCI_MMCCMD       0x30 /* Command Register                  */
55#define DAVINCI_MMCARGHL     0x34 /* Argument Register                 */
56#define DAVINCI_MMCRSP01     0x38 /* Response Register 0 and 1         */
57#define DAVINCI_MMCRSP23     0x3C /* Response Register 0 and 1         */
58#define DAVINCI_MMCRSP45     0x40 /* Response Register 0 and 1         */
59#define DAVINCI_MMCRSP67     0x44 /* Response Register 0 and 1         */
60#define DAVINCI_MMCDRSP      0x48 /* Data Response Register            */
61#define DAVINCI_MMCETOK      0x4C
62#define DAVINCI_MMCCIDX      0x50 /* Command Index Register            */
63#define DAVINCI_MMCCKC       0x54
64#define DAVINCI_MMCTORC      0x58
65#define DAVINCI_MMCTODC      0x5C
66#define DAVINCI_MMCBLNC      0x60
67#define DAVINCI_SDIOCTL      0x64
68#define DAVINCI_SDIOST0      0x68
69#define DAVINCI_SDIOEN       0x6C
70#define DAVINCI_SDIOST       0x70
71#define DAVINCI_MMCFIFOCTL   0x74 /* FIFO Control Register             */
72
73/* DAVINCI_MMCCTL definitions */
74#define MMCCTL_DATRST         (1 << 0)
75#define MMCCTL_CMDRST         (1 << 1)
76#define MMCCTL_WIDTH_8_BIT    (1 << 8)
77#define MMCCTL_WIDTH_4_BIT    (1 << 2)
78#define MMCCTL_DATEG_DISABLED (0 << 6)
79#define MMCCTL_DATEG_RISING   (1 << 6)
80#define MMCCTL_DATEG_FALLING  (2 << 6)
81#define MMCCTL_DATEG_BOTH     (3 << 6)
82#define MMCCTL_PERMDR_LE      (0 << 9)
83#define MMCCTL_PERMDR_BE      (1 << 9)
84#define MMCCTL_PERMDX_LE      (0 << 10)
85#define MMCCTL_PERMDX_BE      (1 << 10)
86
87/* DAVINCI_MMCCLK definitions */
88#define MMCCLK_CLKEN          (1 << 8)
89#define MMCCLK_CLKRT_MASK     (0xFF << 0)
90
91/* IRQ bit definitions, for DAVINCI_MMCST0 and DAVINCI_MMCIM */
92#define MMCST0_DATDNE         BIT(0)	/* data done */
93#define MMCST0_BSYDNE         BIT(1)	/* busy done */
94#define MMCST0_RSPDNE         BIT(2)	/* command done */
95#define MMCST0_TOUTRD         BIT(3)	/* data read timeout */
96#define MMCST0_TOUTRS         BIT(4)	/* command response timeout */
97#define MMCST0_CRCWR          BIT(5)	/* data write CRC error */
98#define MMCST0_CRCRD          BIT(6)	/* data read CRC error */
99#define MMCST0_CRCRS          BIT(7)	/* command response CRC error */
100#define MMCST0_DXRDY          BIT(9)	/* data transmit ready (fifo empty) */
101#define MMCST0_DRRDY          BIT(10)	/* data receive ready (data in fifo)*/
102#define MMCST0_DATED          BIT(11)	/* DAT3 edge detect */
103#define MMCST0_TRNDNE         BIT(12)	/* transfer done */
104
105/* DAVINCI_MMCST1 definitions */
106#define MMCST1_BUSY           (1 << 0)
107
108/* DAVINCI_MMCCMD definitions */
109#define MMCCMD_CMD_MASK       (0x3F << 0)
110#define MMCCMD_PPLEN          (1 << 7)
111#define MMCCMD_BSYEXP         (1 << 8)
112#define MMCCMD_RSPFMT_MASK    (3 << 9)
113#define MMCCMD_RSPFMT_NONE    (0 << 9)
114#define MMCCMD_RSPFMT_R1456   (1 << 9)
115#define MMCCMD_RSPFMT_R2      (2 << 9)
116#define MMCCMD_RSPFMT_R3      (3 << 9)
117#define MMCCMD_DTRW           (1 << 11)
118#define MMCCMD_STRMTP         (1 << 12)
119#define MMCCMD_WDATX          (1 << 13)
120#define MMCCMD_INITCK         (1 << 14)
121#define MMCCMD_DCLR           (1 << 15)
122#define MMCCMD_DMATRIG        (1 << 16)
123
124/* DAVINCI_MMCFIFOCTL definitions */
125#define MMCFIFOCTL_FIFORST    (1 << 0)
126#define MMCFIFOCTL_FIFODIR_WR (1 << 1)
127#define MMCFIFOCTL_FIFODIR_RD (0 << 1)
128#define MMCFIFOCTL_FIFOLEV    (1 << 2) /* 0 = 128 bits, 1 = 256 bits */
129#define MMCFIFOCTL_ACCWD_4    (0 << 3) /* access width of 4 bytes    */
130#define MMCFIFOCTL_ACCWD_3    (1 << 3) /* access width of 3 bytes    */
131#define MMCFIFOCTL_ACCWD_2    (2 << 3) /* access width of 2 bytes    */
132#define MMCFIFOCTL_ACCWD_1    (3 << 3) /* access width of 1 byte     */
133
134
135/* MMCSD Init clock in Hz in opendrain mode */
136#define MMCSD_INIT_CLOCK		200000
137
138/*
139 * One scatterlist dma "segment" is at most MAX_CCNT rw_threshold units,
140 * and we handle up to MAX_NR_SG segments.  MMC_BLOCK_BOUNCE kicks in only
141 * for drivers with max_hw_segs == 1, making the segments bigger (64KB)
142 * than the page or two that's otherwise typical. nr_sg (passed from
143 * platform data) == 16 gives at least the same throughput boost, using
144 * EDMA transfer linkage instead of spending CPU time copying pages.
145 */
146#define MAX_CCNT	((1 << 16) - 1)
147
148#define MAX_NR_SG	16
149
150static unsigned rw_threshold = 32;
151module_param(rw_threshold, uint, S_IRUGO);
152MODULE_PARM_DESC(rw_threshold,
153		"Read/Write threshold. Default = 32");
154
155static unsigned __initdata use_dma = 1;
156module_param(use_dma, uint, 0);
157MODULE_PARM_DESC(use_dma, "Whether to use DMA or not. Default = 1");
158
159struct mmc_davinci_host {
160	struct mmc_command *cmd;
161	struct mmc_data *data;
162	struct mmc_host *mmc;
163	struct clk *clk;
164	unsigned int mmc_input_clk;
165	void __iomem *base;
166	struct resource *mem_res;
167	int irq;
168	unsigned char bus_mode;
169
170#define DAVINCI_MMC_DATADIR_NONE	0
171#define DAVINCI_MMC_DATADIR_READ	1
172#define DAVINCI_MMC_DATADIR_WRITE	2
173	unsigned char data_dir;
174
175	/* buffer is used during PIO of one scatterlist segment, and
176	 * is updated along with buffer_bytes_left.  bytes_left applies
177	 * to all N blocks of the PIO transfer.
178	 */
179	u8 *buffer;
180	u32 buffer_bytes_left;
181	u32 bytes_left;
182
183	u32 rxdma, txdma;
184	bool use_dma;
185	bool do_dma;
186
187	/* Scatterlist DMA uses one or more parameter RAM entries:
188	 * the main one (associated with rxdma or txdma) plus zero or
189	 * more links.  The entries for a given transfer differ only
190	 * by memory buffer (address, length) and link field.
191	 */
192	struct edmacc_param	tx_template;
193	struct edmacc_param	rx_template;
194	unsigned		n_link;
195	u32			links[MAX_NR_SG - 1];
196
197	/* For PIO we walk scatterlists one segment at a time. */
198	unsigned int		sg_len;
199	struct scatterlist *sg;
200
201	/* Version of the MMC/SD controller */
202	u8 version;
203	/* for ns in one cycle calculation */
204	unsigned ns_in_one_cycle;
205	/* Number of sg segments */
206	u8 nr_sg;
207#ifdef CONFIG_CPU_FREQ
208	struct notifier_block	freq_transition;
209#endif
210};
211
212
213/* PIO only */
214static void mmc_davinci_sg_to_buf(struct mmc_davinci_host *host)
215{
216	host->buffer_bytes_left = sg_dma_len(host->sg);
217	host->buffer = sg_virt(host->sg);
218	if (host->buffer_bytes_left > host->bytes_left)
219		host->buffer_bytes_left = host->bytes_left;
220}
221
222static void davinci_fifo_data_trans(struct mmc_davinci_host *host,
223					unsigned int n)
224{
225	u8 *p;
226	unsigned int i;
227
228	if (host->buffer_bytes_left == 0) {
229		host->sg = sg_next(host->data->sg);
230		mmc_davinci_sg_to_buf(host);
231	}
232
233	p = host->buffer;
234	if (n > host->buffer_bytes_left)
235		n = host->buffer_bytes_left;
236	host->buffer_bytes_left -= n;
237	host->bytes_left -= n;
238
239	/* NOTE:  we never transfer more than rw_threshold bytes
240	 * to/from the fifo here; there's no I/O overlap.
241	 * This also assumes that access width( i.e. ACCWD) is 4 bytes
242	 */
243	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
244		for (i = 0; i < (n >> 2); i++) {
245			writel(*((u32 *)p), host->base + DAVINCI_MMCDXR);
246			p = p + 4;
247		}
248		if (n & 3) {
249			iowrite8_rep(host->base + DAVINCI_MMCDXR, p, (n & 3));
250			p = p + (n & 3);
251		}
252	} else {
253		for (i = 0; i < (n >> 2); i++) {
254			*((u32 *)p) = readl(host->base + DAVINCI_MMCDRR);
255			p  = p + 4;
256		}
257		if (n & 3) {
258			ioread8_rep(host->base + DAVINCI_MMCDRR, p, (n & 3));
259			p = p + (n & 3);
260		}
261	}
262	host->buffer = p;
263}
264
265static void mmc_davinci_start_command(struct mmc_davinci_host *host,
266		struct mmc_command *cmd)
267{
268	u32 cmd_reg = 0;
269	u32 im_val;
270
271	dev_dbg(mmc_dev(host->mmc), "CMD%d, arg 0x%08x%s\n",
272		cmd->opcode, cmd->arg,
273		({ char *s;
274		switch (mmc_resp_type(cmd)) {
275		case MMC_RSP_R1:
276			s = ", R1/R5/R6/R7 response";
277			break;
278		case MMC_RSP_R1B:
279			s = ", R1b response";
280			break;
281		case MMC_RSP_R2:
282			s = ", R2 response";
283			break;
284		case MMC_RSP_R3:
285			s = ", R3/R4 response";
286			break;
287		default:
288			s = ", (R? response)";
289			break;
290		}; s; }));
291	host->cmd = cmd;
292
293	switch (mmc_resp_type(cmd)) {
294	case MMC_RSP_R1B:
295		/* There's some spec confusion about when R1B is
296		 * allowed, but if the card doesn't issue a BUSY
297		 * then it's harmless for us to allow it.
298		 */
299		cmd_reg |= MMCCMD_BSYEXP;
300		/* FALLTHROUGH */
301	case MMC_RSP_R1:		/* 48 bits, CRC */
302		cmd_reg |= MMCCMD_RSPFMT_R1456;
303		break;
304	case MMC_RSP_R2:		/* 136 bits, CRC */
305		cmd_reg |= MMCCMD_RSPFMT_R2;
306		break;
307	case MMC_RSP_R3:		/* 48 bits, no CRC */
308		cmd_reg |= MMCCMD_RSPFMT_R3;
309		break;
310	default:
311		cmd_reg |= MMCCMD_RSPFMT_NONE;
312		dev_dbg(mmc_dev(host->mmc), "unknown resp_type %04x\n",
313			mmc_resp_type(cmd));
314		break;
315	}
316
317	/* Set command index */
318	cmd_reg |= cmd->opcode;
319
320	/* Enable EDMA transfer triggers */
321	if (host->do_dma)
322		cmd_reg |= MMCCMD_DMATRIG;
323
324	if (host->version == MMC_CTLR_VERSION_2 && host->data != NULL &&
325			host->data_dir == DAVINCI_MMC_DATADIR_READ)
326		cmd_reg |= MMCCMD_DMATRIG;
327
328	/* Setting whether command involves data transfer or not */
329	if (cmd->data)
330		cmd_reg |= MMCCMD_WDATX;
331
332	/* Setting whether stream or block transfer */
333	if (cmd->flags & MMC_DATA_STREAM)
334		cmd_reg |= MMCCMD_STRMTP;
335
336	/* Setting whether data read or write */
337	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE)
338		cmd_reg |= MMCCMD_DTRW;
339
340	if (host->bus_mode == MMC_BUSMODE_PUSHPULL)
341		cmd_reg |= MMCCMD_PPLEN;
342
343	/* set Command timeout */
344	writel(0x1FFF, host->base + DAVINCI_MMCTOR);
345
346	/* Enable interrupt (calculate here, defer until FIFO is stuffed). */
347	im_val =  MMCST0_RSPDNE | MMCST0_CRCRS | MMCST0_TOUTRS;
348	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
349		im_val |= MMCST0_DATDNE | MMCST0_CRCWR;
350
351		if (!host->do_dma)
352			im_val |= MMCST0_DXRDY;
353	} else if (host->data_dir == DAVINCI_MMC_DATADIR_READ) {
354		im_val |= MMCST0_DATDNE | MMCST0_CRCRD | MMCST0_TOUTRD;
355
356		if (!host->do_dma)
357			im_val |= MMCST0_DRRDY;
358	}
359
360	/*
361	 * Before non-DMA WRITE commands the controller needs priming:
362	 * FIFO should be populated with 32 bytes i.e. whatever is the FIFO size
363	 */
364	if (!host->do_dma && (host->data_dir == DAVINCI_MMC_DATADIR_WRITE))
365		davinci_fifo_data_trans(host, rw_threshold);
366
367	writel(cmd->arg, host->base + DAVINCI_MMCARGHL);
368	writel(cmd_reg,  host->base + DAVINCI_MMCCMD);
369	writel(im_val, host->base + DAVINCI_MMCIM);
370}
371
372/*----------------------------------------------------------------------*/
373
374/* DMA infrastructure */
375
376static void davinci_abort_dma(struct mmc_davinci_host *host)
377{
378	int sync_dev;
379
380	if (host->data_dir == DAVINCI_MMC_DATADIR_READ)
381		sync_dev = host->rxdma;
382	else
383		sync_dev = host->txdma;
384
385	edma_stop(sync_dev);
386	edma_clean_channel(sync_dev);
387}
388
389static void
390mmc_davinci_xfer_done(struct mmc_davinci_host *host, struct mmc_data *data);
391
392static void mmc_davinci_dma_cb(unsigned channel, u16 ch_status, void *data)
393{
394	if (DMA_COMPLETE != ch_status) {
395		struct mmc_davinci_host *host = data;
396
397		/* Currently means:  DMA Event Missed, or "null" transfer
398		 * request was seen.  In the future, TC errors (like bad
399		 * addresses) might be presented too.
400		 */
401		dev_warn(mmc_dev(host->mmc), "DMA %s error\n",
402			(host->data->flags & MMC_DATA_WRITE)
403				? "write" : "read");
404		host->data->error = -EIO;
405		mmc_davinci_xfer_done(host, host->data);
406	}
407}
408
409/* Set up tx or rx template, to be modified and updated later */
410static void __init mmc_davinci_dma_setup(struct mmc_davinci_host *host,
411		bool tx, struct edmacc_param *template)
412{
413	unsigned	sync_dev;
414	const u16	acnt = 4;
415	const u16	bcnt = rw_threshold >> 2;
416	const u16	ccnt = 0;
417	u32		src_port = 0;
418	u32		dst_port = 0;
419	s16		src_bidx, dst_bidx;
420	s16		src_cidx, dst_cidx;
421
422	/*
423	 * A-B Sync transfer:  each DMA request is for one "frame" of
424	 * rw_threshold bytes, broken into "acnt"-size chunks repeated
425	 * "bcnt" times.  Each segment needs "ccnt" such frames; since
426	 * we tell the block layer our mmc->max_seg_size limit, we can
427	 * trust (later) that it's within bounds.
428	 *
429	 * The FIFOs are read/written in 4-byte chunks (acnt == 4) and
430	 * EDMA will optimize memory operations to use larger bursts.
431	 */
432	if (tx) {
433		sync_dev = host->txdma;
434
435		/* src_prt, ccnt, and link to be set up later */
436		src_bidx = acnt;
437		src_cidx = acnt * bcnt;
438
439		dst_port = host->mem_res->start + DAVINCI_MMCDXR;
440		dst_bidx = 0;
441		dst_cidx = 0;
442	} else {
443		sync_dev = host->rxdma;
444
445		src_port = host->mem_res->start + DAVINCI_MMCDRR;
446		src_bidx = 0;
447		src_cidx = 0;
448
449		/* dst_prt, ccnt, and link to be set up later */
450		dst_bidx = acnt;
451		dst_cidx = acnt * bcnt;
452	}
453
454	/*
455	 * We can't use FIFO mode for the FIFOs because MMC FIFO addresses
456	 * are not 256-bit (32-byte) aligned.  So we use INCR, and the W8BIT
457	 * parameter is ignored.
458	 */
459	edma_set_src(sync_dev, src_port, INCR, W8BIT);
460	edma_set_dest(sync_dev, dst_port, INCR, W8BIT);
461
462	edma_set_src_index(sync_dev, src_bidx, src_cidx);
463	edma_set_dest_index(sync_dev, dst_bidx, dst_cidx);
464
465	edma_set_transfer_params(sync_dev, acnt, bcnt, ccnt, 8, ABSYNC);
466
467	edma_read_slot(sync_dev, template);
468
469	/* don't bother with irqs or chaining */
470	template->opt |= EDMA_CHAN_SLOT(sync_dev) << 12;
471}
472
473static void mmc_davinci_send_dma_request(struct mmc_davinci_host *host,
474		struct mmc_data *data)
475{
476	struct edmacc_param	*template;
477	int			channel, slot;
478	unsigned		link;
479	struct scatterlist	*sg;
480	unsigned		sg_len;
481	unsigned		bytes_left = host->bytes_left;
482	const unsigned		shift = ffs(rw_threshold) - 1;;
483
484	if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) {
485		template = &host->tx_template;
486		channel = host->txdma;
487	} else {
488		template = &host->rx_template;
489		channel = host->rxdma;
490	}
491
492	/* We know sg_len and ccnt will never be out of range because
493	 * we told the mmc layer which in turn tells the block layer
494	 * to ensure that it only hands us one scatterlist segment
495	 * per EDMA PARAM entry.  Update the PARAM
496	 * entries needed for each segment of this scatterlist.
497	 */
498	for (slot = channel, link = 0, sg = data->sg, sg_len = host->sg_len;
499			sg_len-- != 0 && bytes_left;
500			sg = sg_next(sg), slot = host->links[link++]) {
501		u32		buf = sg_dma_address(sg);
502		unsigned	count = sg_dma_len(sg);
503
504		template->link_bcntrld = sg_len
505				? (EDMA_CHAN_SLOT(host->links[link]) << 5)
506				: 0xffff;
507
508		if (count > bytes_left)
509			count = bytes_left;
510		bytes_left -= count;
511
512		if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE)
513			template->src = buf;
514		else
515			template->dst = buf;
516		template->ccnt = count >> shift;
517
518		edma_write_slot(slot, template);
519	}
520
521	if (host->version == MMC_CTLR_VERSION_2)
522		edma_clear_event(channel);
523
524	edma_start(channel);
525}
526
527static int mmc_davinci_start_dma_transfer(struct mmc_davinci_host *host,
528		struct mmc_data *data)
529{
530	int i;
531	int mask = rw_threshold - 1;
532
533	host->sg_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
534				((data->flags & MMC_DATA_WRITE)
535				? DMA_TO_DEVICE
536				: DMA_FROM_DEVICE));
537
538	/* no individual DMA segment should need a partial FIFO */
539	for (i = 0; i < host->sg_len; i++) {
540		if (sg_dma_len(data->sg + i) & mask) {
541			dma_unmap_sg(mmc_dev(host->mmc),
542					data->sg, data->sg_len,
543					(data->flags & MMC_DATA_WRITE)
544					? DMA_TO_DEVICE
545					: DMA_FROM_DEVICE);
546			return -1;
547		}
548	}
549
550	host->do_dma = 1;
551	mmc_davinci_send_dma_request(host, data);
552
553	return 0;
554}
555
556static void __init_or_module
557davinci_release_dma_channels(struct mmc_davinci_host *host)
558{
559	unsigned	i;
560
561	if (!host->use_dma)
562		return;
563
564	for (i = 0; i < host->n_link; i++)
565		edma_free_slot(host->links[i]);
566
567	edma_free_channel(host->txdma);
568	edma_free_channel(host->rxdma);
569}
570
571static int __init davinci_acquire_dma_channels(struct mmc_davinci_host *host)
572{
573	u32 link_size;
574	int r, i;
575
576	/* Acquire master DMA write channel */
577	r = edma_alloc_channel(host->txdma, mmc_davinci_dma_cb, host,
578			EVENTQ_DEFAULT);
579	if (r < 0) {
580		dev_warn(mmc_dev(host->mmc), "alloc %s channel err %d\n",
581				"tx", r);
582		return r;
583	}
584	mmc_davinci_dma_setup(host, true, &host->tx_template);
585
586	/* Acquire master DMA read channel */
587	r = edma_alloc_channel(host->rxdma, mmc_davinci_dma_cb, host,
588			EVENTQ_DEFAULT);
589	if (r < 0) {
590		dev_warn(mmc_dev(host->mmc), "alloc %s channel err %d\n",
591				"rx", r);
592		goto free_master_write;
593	}
594	mmc_davinci_dma_setup(host, false, &host->rx_template);
595
596	/* Allocate parameter RAM slots, which will later be bound to a
597	 * channel as needed to handle a scatterlist.
598	 */
599	link_size = min_t(unsigned, host->nr_sg, ARRAY_SIZE(host->links));
600	for (i = 0; i < link_size; i++) {
601		r = edma_alloc_slot(EDMA_CTLR(host->txdma), EDMA_SLOT_ANY);
602		if (r < 0) {
603			dev_dbg(mmc_dev(host->mmc), "dma PaRAM alloc --> %d\n",
604				r);
605			break;
606		}
607		host->links[i] = r;
608	}
609	host->n_link = i;
610
611	return 0;
612
613free_master_write:
614	edma_free_channel(host->txdma);
615
616	return r;
617}
618
619/*----------------------------------------------------------------------*/
620
621static void
622mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req)
623{
624	int fifo_lev = (rw_threshold == 32) ? MMCFIFOCTL_FIFOLEV : 0;
625	int timeout;
626	struct mmc_data *data = req->data;
627
628	if (host->version == MMC_CTLR_VERSION_2)
629		fifo_lev = (rw_threshold == 64) ? MMCFIFOCTL_FIFOLEV : 0;
630
631	host->data = data;
632	if (data == NULL) {
633		host->data_dir = DAVINCI_MMC_DATADIR_NONE;
634		writel(0, host->base + DAVINCI_MMCBLEN);
635		writel(0, host->base + DAVINCI_MMCNBLK);
636		return;
637	}
638
639	dev_dbg(mmc_dev(host->mmc), "%s %s, %d blocks of %d bytes\n",
640		(data->flags & MMC_DATA_STREAM) ? "stream" : "block",
641		(data->flags & MMC_DATA_WRITE) ? "write" : "read",
642		data->blocks, data->blksz);
643	dev_dbg(mmc_dev(host->mmc), "  DTO %d cycles + %d ns\n",
644		data->timeout_clks, data->timeout_ns);
645	timeout = data->timeout_clks +
646		(data->timeout_ns / host->ns_in_one_cycle);
647	if (timeout > 0xffff)
648		timeout = 0xffff;
649
650	writel(timeout, host->base + DAVINCI_MMCTOD);
651	writel(data->blocks, host->base + DAVINCI_MMCNBLK);
652	writel(data->blksz, host->base + DAVINCI_MMCBLEN);
653
654	/* Configure the FIFO */
655	switch (data->flags & MMC_DATA_WRITE) {
656	case MMC_DATA_WRITE:
657		host->data_dir = DAVINCI_MMC_DATADIR_WRITE;
658		writel(fifo_lev | MMCFIFOCTL_FIFODIR_WR | MMCFIFOCTL_FIFORST,
659			host->base + DAVINCI_MMCFIFOCTL);
660		writel(fifo_lev | MMCFIFOCTL_FIFODIR_WR,
661			host->base + DAVINCI_MMCFIFOCTL);
662		break;
663
664	default:
665		host->data_dir = DAVINCI_MMC_DATADIR_READ;
666		writel(fifo_lev | MMCFIFOCTL_FIFODIR_RD | MMCFIFOCTL_FIFORST,
667			host->base + DAVINCI_MMCFIFOCTL);
668		writel(fifo_lev | MMCFIFOCTL_FIFODIR_RD,
669			host->base + DAVINCI_MMCFIFOCTL);
670		break;
671	}
672
673	host->buffer = NULL;
674	host->bytes_left = data->blocks * data->blksz;
675
676	/* For now we try to use DMA whenever we won't need partial FIFO
677	 * reads or writes, either for the whole transfer (as tested here)
678	 * or for any individual scatterlist segment (tested when we call
679	 * start_dma_transfer).
680	 *
681	 * While we *could* change that, unusual block sizes are rarely
682	 * used.  The occasional fallback to PIO should't hurt.
683	 */
684	if (host->use_dma && (host->bytes_left & (rw_threshold - 1)) == 0
685			&& mmc_davinci_start_dma_transfer(host, data) == 0) {
686		/* zero this to ensure we take no PIO paths */
687		host->bytes_left = 0;
688	} else {
689		/* Revert to CPU Copy */
690		host->sg_len = data->sg_len;
691		host->sg = host->data->sg;
692		mmc_davinci_sg_to_buf(host);
693	}
694}
695
696static void mmc_davinci_request(struct mmc_host *mmc, struct mmc_request *req)
697{
698	struct mmc_davinci_host *host = mmc_priv(mmc);
699	unsigned long timeout = jiffies + msecs_to_jiffies(900);
700	u32 mmcst1 = 0;
701
702	/* Card may still be sending BUSY after a previous operation,
703	 * typically some kind of write.  If so, we can't proceed yet.
704	 */
705	while (time_before(jiffies, timeout)) {
706		mmcst1  = readl(host->base + DAVINCI_MMCST1);
707		if (!(mmcst1 & MMCST1_BUSY))
708			break;
709		cpu_relax();
710	}
711	if (mmcst1 & MMCST1_BUSY) {
712		dev_err(mmc_dev(host->mmc), "still BUSY? bad ... \n");
713		req->cmd->error = -ETIMEDOUT;
714		mmc_request_done(mmc, req);
715		return;
716	}
717
718	host->do_dma = 0;
719	mmc_davinci_prepare_data(host, req);
720	mmc_davinci_start_command(host, req->cmd);
721}
722
723static unsigned int calculate_freq_for_card(struct mmc_davinci_host *host,
724	unsigned int mmc_req_freq)
725{
726	unsigned int mmc_freq = 0, mmc_pclk = 0, mmc_push_pull_divisor = 0;
727
728	mmc_pclk = host->mmc_input_clk;
729	if (mmc_req_freq && mmc_pclk > (2 * mmc_req_freq))
730		mmc_push_pull_divisor = ((unsigned int)mmc_pclk
731				/ (2 * mmc_req_freq)) - 1;
732	else
733		mmc_push_pull_divisor = 0;
734
735	mmc_freq = (unsigned int)mmc_pclk
736		/ (2 * (mmc_push_pull_divisor + 1));
737
738	if (mmc_freq > mmc_req_freq)
739		mmc_push_pull_divisor = mmc_push_pull_divisor + 1;
740	/* Convert ns to clock cycles */
741	if (mmc_req_freq <= 400000)
742		host->ns_in_one_cycle = (1000000) / (((mmc_pclk
743				/ (2 * (mmc_push_pull_divisor + 1)))/1000));
744	else
745		host->ns_in_one_cycle = (1000000) / (((mmc_pclk
746				/ (2 * (mmc_push_pull_divisor + 1)))/1000000));
747
748	return mmc_push_pull_divisor;
749}
750
751static void calculate_clk_divider(struct mmc_host *mmc, struct mmc_ios *ios)
752{
753	unsigned int open_drain_freq = 0, mmc_pclk = 0;
754	unsigned int mmc_push_pull_freq = 0;
755	struct mmc_davinci_host *host = mmc_priv(mmc);
756
757	if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
758		u32 temp;
759
760		/* Ignoring the init clock value passed for fixing the inter
761		 * operability with different cards.
762		 */
763		open_drain_freq = ((unsigned int)mmc_pclk
764				/ (2 * MMCSD_INIT_CLOCK)) - 1;
765
766		if (open_drain_freq > 0xFF)
767			open_drain_freq = 0xFF;
768
769		temp = readl(host->base + DAVINCI_MMCCLK) & ~MMCCLK_CLKRT_MASK;
770		temp |= open_drain_freq;
771		writel(temp, host->base + DAVINCI_MMCCLK);
772
773		/* Convert ns to clock cycles */
774		host->ns_in_one_cycle = (1000000) / (MMCSD_INIT_CLOCK/1000);
775	} else {
776		u32 temp;
777		mmc_push_pull_freq = calculate_freq_for_card(host, ios->clock);
778
779		if (mmc_push_pull_freq > 0xFF)
780			mmc_push_pull_freq = 0xFF;
781
782		temp = readl(host->base + DAVINCI_MMCCLK) & ~MMCCLK_CLKEN;
783		writel(temp, host->base + DAVINCI_MMCCLK);
784
785		udelay(10);
786
787		temp = readl(host->base + DAVINCI_MMCCLK) & ~MMCCLK_CLKRT_MASK;
788		temp |= mmc_push_pull_freq;
789		writel(temp, host->base + DAVINCI_MMCCLK);
790
791		writel(temp | MMCCLK_CLKEN, host->base + DAVINCI_MMCCLK);
792
793		udelay(10);
794	}
795}
796
797static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
798{
799	struct mmc_davinci_host *host = mmc_priv(mmc);
800
801	dev_dbg(mmc_dev(host->mmc),
802		"clock %dHz busmode %d powermode %d Vdd %04x\n",
803		ios->clock, ios->bus_mode, ios->power_mode,
804		ios->vdd);
805
806	switch (ios->bus_width) {
807	case MMC_BUS_WIDTH_8:
808		dev_dbg(mmc_dev(host->mmc), "Enabling 8 bit mode\n");
809		writel((readl(host->base + DAVINCI_MMCCTL) &
810			~MMCCTL_WIDTH_4_BIT) | MMCCTL_WIDTH_8_BIT,
811			host->base + DAVINCI_MMCCTL);
812		break;
813	case MMC_BUS_WIDTH_4:
814		dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
815		if (host->version == MMC_CTLR_VERSION_2)
816			writel((readl(host->base + DAVINCI_MMCCTL) &
817				~MMCCTL_WIDTH_8_BIT) | MMCCTL_WIDTH_4_BIT,
818				host->base + DAVINCI_MMCCTL);
819		else
820			writel(readl(host->base + DAVINCI_MMCCTL) |
821				MMCCTL_WIDTH_4_BIT,
822				host->base + DAVINCI_MMCCTL);
823		break;
824	case MMC_BUS_WIDTH_1:
825		dev_dbg(mmc_dev(host->mmc), "Enabling 1 bit mode\n");
826		if (host->version == MMC_CTLR_VERSION_2)
827			writel(readl(host->base + DAVINCI_MMCCTL) &
828				~(MMCCTL_WIDTH_8_BIT | MMCCTL_WIDTH_4_BIT),
829				host->base + DAVINCI_MMCCTL);
830		else
831			writel(readl(host->base + DAVINCI_MMCCTL) &
832				~MMCCTL_WIDTH_4_BIT,
833				host->base + DAVINCI_MMCCTL);
834		break;
835	}
836
837	calculate_clk_divider(mmc, ios);
838
839	host->bus_mode = ios->bus_mode;
840	if (ios->power_mode == MMC_POWER_UP) {
841		unsigned long timeout = jiffies + msecs_to_jiffies(50);
842		bool lose = true;
843
844		/* Send clock cycles, poll completion */
845		writel(0, host->base + DAVINCI_MMCARGHL);
846		writel(MMCCMD_INITCK, host->base + DAVINCI_MMCCMD);
847		while (time_before(jiffies, timeout)) {
848			u32 tmp = readl(host->base + DAVINCI_MMCST0);
849
850			if (tmp & MMCST0_RSPDNE) {
851				lose = false;
852				break;
853			}
854			cpu_relax();
855		}
856		if (lose)
857			dev_warn(mmc_dev(host->mmc), "powerup timeout\n");
858	}
859
860	/* FIXME on power OFF, reset things ... */
861}
862
863static void
864mmc_davinci_xfer_done(struct mmc_davinci_host *host, struct mmc_data *data)
865{
866	host->data = NULL;
867
868	if (host->do_dma) {
869		davinci_abort_dma(host);
870
871		dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
872			     (data->flags & MMC_DATA_WRITE)
873			     ? DMA_TO_DEVICE
874			     : DMA_FROM_DEVICE);
875		host->do_dma = false;
876	}
877	host->data_dir = DAVINCI_MMC_DATADIR_NONE;
878
879	if (!data->stop || (host->cmd && host->cmd->error)) {
880		mmc_request_done(host->mmc, data->mrq);
881		writel(0, host->base + DAVINCI_MMCIM);
882	} else
883		mmc_davinci_start_command(host, data->stop);
884}
885
886static void mmc_davinci_cmd_done(struct mmc_davinci_host *host,
887				 struct mmc_command *cmd)
888{
889	host->cmd = NULL;
890
891	if (cmd->flags & MMC_RSP_PRESENT) {
892		if (cmd->flags & MMC_RSP_136) {
893			/* response type 2 */
894			cmd->resp[3] = readl(host->base + DAVINCI_MMCRSP01);
895			cmd->resp[2] = readl(host->base + DAVINCI_MMCRSP23);
896			cmd->resp[1] = readl(host->base + DAVINCI_MMCRSP45);
897			cmd->resp[0] = readl(host->base + DAVINCI_MMCRSP67);
898		} else {
899			/* response types 1, 1b, 3, 4, 5, 6 */
900			cmd->resp[0] = readl(host->base + DAVINCI_MMCRSP67);
901		}
902	}
903
904	if (host->data == NULL || cmd->error) {
905		if (cmd->error == -ETIMEDOUT)
906			cmd->mrq->cmd->retries = 0;
907		mmc_request_done(host->mmc, cmd->mrq);
908		writel(0, host->base + DAVINCI_MMCIM);
909	}
910}
911
912static void
913davinci_abort_data(struct mmc_davinci_host *host, struct mmc_data *data)
914{
915	u32 temp;
916
917	/* reset command and data state machines */
918	temp = readl(host->base + DAVINCI_MMCCTL);
919	writel(temp | MMCCTL_CMDRST | MMCCTL_DATRST,
920		host->base + DAVINCI_MMCCTL);
921
922	temp &= ~(MMCCTL_CMDRST | MMCCTL_DATRST);
923	udelay(10);
924	writel(temp, host->base + DAVINCI_MMCCTL);
925}
926
927static irqreturn_t mmc_davinci_irq(int irq, void *dev_id)
928{
929	struct mmc_davinci_host *host = (struct mmc_davinci_host *)dev_id;
930	unsigned int status, qstatus;
931	int end_command = 0;
932	int end_transfer = 0;
933	struct mmc_data *data = host->data;
934
935	if (host->cmd == NULL && host->data == NULL) {
936		status = readl(host->base + DAVINCI_MMCST0);
937		dev_dbg(mmc_dev(host->mmc),
938			"Spurious interrupt 0x%04x\n", status);
939		/* Disable the interrupt from mmcsd */
940		writel(0, host->base + DAVINCI_MMCIM);
941		return IRQ_NONE;
942	}
943
944	status = readl(host->base + DAVINCI_MMCST0);
945	qstatus = status;
946
947	/* handle FIFO first when using PIO for data.
948	 * bytes_left will decrease to zero as I/O progress and status will
949	 * read zero over iteration because this controller status
950	 * register(MMCST0) reports any status only once and it is cleared
951	 * by read. So, it is not unbouned loop even in the case of
952	 * non-dma.
953	 */
954	while (host->bytes_left && (status & (MMCST0_DXRDY | MMCST0_DRRDY))) {
955		davinci_fifo_data_trans(host, rw_threshold);
956		status = readl(host->base + DAVINCI_MMCST0);
957		if (!status)
958			break;
959		qstatus |= status;
960	}
961
962	if (qstatus & MMCST0_DATDNE) {
963		/* All blocks sent/received, and CRC checks passed */
964		if (data != NULL) {
965			if ((host->do_dma == 0) && (host->bytes_left > 0)) {
966				/* if datasize < rw_threshold
967				 * no RX ints are generated
968				 */
969				davinci_fifo_data_trans(host, host->bytes_left);
970			}
971			end_transfer = 1;
972			data->bytes_xfered = data->blocks * data->blksz;
973		} else {
974			dev_err(mmc_dev(host->mmc),
975					"DATDNE with no host->data\n");
976		}
977	}
978
979	if (qstatus & MMCST0_TOUTRD) {
980		/* Read data timeout */
981		data->error = -ETIMEDOUT;
982		end_transfer = 1;
983
984		dev_dbg(mmc_dev(host->mmc),
985			"read data timeout, status %x\n",
986			qstatus);
987
988		davinci_abort_data(host, data);
989	}
990
991	if (qstatus & (MMCST0_CRCWR | MMCST0_CRCRD)) {
992		/* Data CRC error */
993		data->error = -EILSEQ;
994		end_transfer = 1;
995
996		/* NOTE:  this controller uses CRCWR to report both CRC
997		 * errors and timeouts (on writes).  MMCDRSP values are
998		 * only weakly documented, but 0x9f was clearly a timeout
999		 * case and the two three-bit patterns in various SD specs
1000		 * (101, 010) aren't part of it ...
1001		 */
1002		if (qstatus & MMCST0_CRCWR) {
1003			u32 temp = readb(host->base + DAVINCI_MMCDRSP);
1004
1005			if (temp == 0x9f)
1006				data->error = -ETIMEDOUT;
1007		}
1008		dev_dbg(mmc_dev(host->mmc), "data %s %s error\n",
1009			(qstatus & MMCST0_CRCWR) ? "write" : "read",
1010			(data->error == -ETIMEDOUT) ? "timeout" : "CRC");
1011
1012		davinci_abort_data(host, data);
1013	}
1014
1015	if (qstatus & MMCST0_TOUTRS) {
1016		/* Command timeout */
1017		if (host->cmd) {
1018			dev_dbg(mmc_dev(host->mmc),
1019				"CMD%d timeout, status %x\n",
1020				host->cmd->opcode, qstatus);
1021			host->cmd->error = -ETIMEDOUT;
1022			if (data) {
1023				end_transfer = 1;
1024				davinci_abort_data(host, data);
1025			} else
1026				end_command = 1;
1027		}
1028	}
1029
1030	if (qstatus & MMCST0_CRCRS) {
1031		/* Command CRC error */
1032		dev_dbg(mmc_dev(host->mmc), "Command CRC error\n");
1033		if (host->cmd) {
1034			host->cmd->error = -EILSEQ;
1035			end_command = 1;
1036		}
1037	}
1038
1039	if (qstatus & MMCST0_RSPDNE) {
1040		/* End of command phase */
1041		end_command = (int) host->cmd;
1042	}
1043
1044	if (end_command)
1045		mmc_davinci_cmd_done(host, host->cmd);
1046	if (end_transfer)
1047		mmc_davinci_xfer_done(host, data);
1048	return IRQ_HANDLED;
1049}
1050
1051static int mmc_davinci_get_cd(struct mmc_host *mmc)
1052{
1053	struct platform_device *pdev = to_platform_device(mmc->parent);
1054	struct davinci_mmc_config *config = pdev->dev.platform_data;
1055
1056	if (!config || !config->get_cd)
1057		return -ENOSYS;
1058	return config->get_cd(pdev->id);
1059}
1060
1061static int mmc_davinci_get_ro(struct mmc_host *mmc)
1062{
1063	struct platform_device *pdev = to_platform_device(mmc->parent);
1064	struct davinci_mmc_config *config = pdev->dev.platform_data;
1065
1066	if (!config || !config->get_ro)
1067		return -ENOSYS;
1068	return config->get_ro(pdev->id);
1069}
1070
1071static struct mmc_host_ops mmc_davinci_ops = {
1072	.request	= mmc_davinci_request,
1073	.set_ios	= mmc_davinci_set_ios,
1074	.get_cd		= mmc_davinci_get_cd,
1075	.get_ro		= mmc_davinci_get_ro,
1076};
1077
1078/*----------------------------------------------------------------------*/
1079
1080#ifdef CONFIG_CPU_FREQ
1081static int mmc_davinci_cpufreq_transition(struct notifier_block *nb,
1082				     unsigned long val, void *data)
1083{
1084	struct mmc_davinci_host *host;
1085	unsigned int mmc_pclk;
1086	struct mmc_host *mmc;
1087	unsigned long flags;
1088
1089	host = container_of(nb, struct mmc_davinci_host, freq_transition);
1090	mmc = host->mmc;
1091	mmc_pclk = clk_get_rate(host->clk);
1092
1093	if (val == CPUFREQ_POSTCHANGE) {
1094		spin_lock_irqsave(&mmc->lock, flags);
1095		host->mmc_input_clk = mmc_pclk;
1096		calculate_clk_divider(mmc, &mmc->ios);
1097		spin_unlock_irqrestore(&mmc->lock, flags);
1098	}
1099
1100	return 0;
1101}
1102
1103static inline int mmc_davinci_cpufreq_register(struct mmc_davinci_host *host)
1104{
1105	host->freq_transition.notifier_call = mmc_davinci_cpufreq_transition;
1106
1107	return cpufreq_register_notifier(&host->freq_transition,
1108					 CPUFREQ_TRANSITION_NOTIFIER);
1109}
1110
1111static inline void mmc_davinci_cpufreq_deregister(struct mmc_davinci_host *host)
1112{
1113	cpufreq_unregister_notifier(&host->freq_transition,
1114				    CPUFREQ_TRANSITION_NOTIFIER);
1115}
1116#else
1117static inline int mmc_davinci_cpufreq_register(struct mmc_davinci_host *host)
1118{
1119	return 0;
1120}
1121
1122static inline void mmc_davinci_cpufreq_deregister(struct mmc_davinci_host *host)
1123{
1124}
1125#endif
1126static void __init init_mmcsd_host(struct mmc_davinci_host *host)
1127{
1128	/* DAT line portion is diabled and in reset state */
1129	writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_DATRST,
1130		host->base + DAVINCI_MMCCTL);
1131
1132	/* CMD line portion is diabled and in reset state */
1133	writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_CMDRST,
1134		host->base + DAVINCI_MMCCTL);
1135
1136	udelay(10);
1137
1138	writel(0, host->base + DAVINCI_MMCCLK);
1139	writel(MMCCLK_CLKEN, host->base + DAVINCI_MMCCLK);
1140
1141	writel(0x1FFF, host->base + DAVINCI_MMCTOR);
1142	writel(0xFFFF, host->base + DAVINCI_MMCTOD);
1143
1144	writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_DATRST,
1145		host->base + DAVINCI_MMCCTL);
1146	writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_CMDRST,
1147		host->base + DAVINCI_MMCCTL);
1148
1149	udelay(10);
1150}
1151
1152static int __init davinci_mmcsd_probe(struct platform_device *pdev)
1153{
1154	struct davinci_mmc_config *pdata = pdev->dev.platform_data;
1155	struct mmc_davinci_host *host = NULL;
1156	struct mmc_host *mmc = NULL;
1157	struct resource *r, *mem = NULL;
1158	int ret = 0, irq = 0;
1159	size_t mem_size;
1160
1161	/* REVISIT:  when we're fully converted, fail if pdata is NULL */
1162
1163	ret = -ENODEV;
1164	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1165	irq = platform_get_irq(pdev, 0);
1166	if (!r || irq == NO_IRQ)
1167		goto out;
1168
1169	ret = -EBUSY;
1170	mem_size = resource_size(r);
1171	mem = request_mem_region(r->start, mem_size, pdev->name);
1172	if (!mem)
1173		goto out;
1174
1175	ret = -ENOMEM;
1176	mmc = mmc_alloc_host(sizeof(struct mmc_davinci_host), &pdev->dev);
1177	if (!mmc)
1178		goto out;
1179
1180	host = mmc_priv(mmc);
1181	host->mmc = mmc;	/* Important */
1182
1183	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1184	if (!r)
1185		goto out;
1186	host->rxdma = r->start;
1187
1188	r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
1189	if (!r)
1190		goto out;
1191	host->txdma = r->start;
1192
1193	host->mem_res = mem;
1194	host->base = ioremap(mem->start, mem_size);
1195	if (!host->base)
1196		goto out;
1197
1198	ret = -ENXIO;
1199	host->clk = clk_get(&pdev->dev, "MMCSDCLK");
1200	if (IS_ERR(host->clk)) {
1201		ret = PTR_ERR(host->clk);
1202		goto out;
1203	}
1204	clk_enable(host->clk);
1205	host->mmc_input_clk = clk_get_rate(host->clk);
1206
1207	init_mmcsd_host(host);
1208
1209	if (pdata->nr_sg)
1210		host->nr_sg = pdata->nr_sg - 1;
1211
1212	if (host->nr_sg > MAX_NR_SG || !host->nr_sg)
1213		host->nr_sg = MAX_NR_SG;
1214
1215	host->use_dma = use_dma;
1216	host->irq = irq;
1217
1218	if (host->use_dma && davinci_acquire_dma_channels(host) != 0)
1219		host->use_dma = 0;
1220
1221	/* REVISIT:  someday, support IRQ-driven card detection.  */
1222	mmc->caps |= MMC_CAP_NEEDS_POLL;
1223	mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
1224
1225	if (pdata && (pdata->wires == 4 || pdata->wires == 0))
1226		mmc->caps |= MMC_CAP_4_BIT_DATA;
1227
1228	if (pdata && (pdata->wires == 8))
1229		mmc->caps |= (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA);
1230
1231	host->version = pdata->version;
1232
1233	mmc->ops = &mmc_davinci_ops;
1234	mmc->f_min = 312500;
1235	mmc->f_max = 25000000;
1236	if (pdata && pdata->max_freq)
1237		mmc->f_max = pdata->max_freq;
1238	if (pdata && pdata->caps)
1239		mmc->caps |= pdata->caps;
1240	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1241
1242	/* With no iommu coalescing pages, each phys_seg is a hw_seg.
1243	 * Each hw_seg uses one EDMA parameter RAM slot, always one
1244	 * channel and then usually some linked slots.
1245	 */
1246	mmc->max_hw_segs	= 1 + host->n_link;
1247	mmc->max_phys_segs	= mmc->max_hw_segs;
1248
1249	/* EDMA limit per hw segment (one or two MBytes) */
1250	mmc->max_seg_size	= MAX_CCNT * rw_threshold;
1251
1252	/* MMC/SD controller limits for multiblock requests */
1253	mmc->max_blk_size	= 4095;  /* BLEN is 12 bits */
1254	mmc->max_blk_count	= 65535; /* NBLK is 16 bits */
1255	mmc->max_req_size	= mmc->max_blk_size * mmc->max_blk_count;
1256
1257	dev_dbg(mmc_dev(host->mmc), "max_phys_segs=%d\n", mmc->max_phys_segs);
1258	dev_dbg(mmc_dev(host->mmc), "max_hw_segs=%d\n", mmc->max_hw_segs);
1259	dev_dbg(mmc_dev(host->mmc), "max_blk_size=%d\n", mmc->max_blk_size);
1260	dev_dbg(mmc_dev(host->mmc), "max_req_size=%d\n", mmc->max_req_size);
1261	dev_dbg(mmc_dev(host->mmc), "max_seg_size=%d\n", mmc->max_seg_size);
1262
1263	platform_set_drvdata(pdev, host);
1264
1265	ret = mmc_davinci_cpufreq_register(host);
1266	if (ret) {
1267		dev_err(&pdev->dev, "failed to register cpufreq\n");
1268		goto cpu_freq_fail;
1269	}
1270
1271	ret = mmc_add_host(mmc);
1272	if (ret < 0)
1273		goto out;
1274
1275	ret = request_irq(irq, mmc_davinci_irq, 0, mmc_hostname(mmc), host);
1276	if (ret)
1277		goto out;
1278
1279	rename_region(mem, mmc_hostname(mmc));
1280
1281	dev_info(mmc_dev(host->mmc), "Using %s, %d-bit mode\n",
1282		host->use_dma ? "DMA" : "PIO",
1283		(mmc->caps & MMC_CAP_4_BIT_DATA) ? 4 : 1);
1284
1285	return 0;
1286
1287out:
1288	mmc_davinci_cpufreq_deregister(host);
1289cpu_freq_fail:
1290	if (host) {
1291		davinci_release_dma_channels(host);
1292
1293		if (host->clk) {
1294			clk_disable(host->clk);
1295			clk_put(host->clk);
1296		}
1297
1298		if (host->base)
1299			iounmap(host->base);
1300	}
1301
1302	if (mmc)
1303		mmc_free_host(mmc);
1304
1305	if (mem)
1306		release_resource(mem);
1307
1308	dev_dbg(&pdev->dev, "probe err %d\n", ret);
1309
1310	return ret;
1311}
1312
1313static int __exit davinci_mmcsd_remove(struct platform_device *pdev)
1314{
1315	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
1316
1317	platform_set_drvdata(pdev, NULL);
1318	if (host) {
1319		mmc_davinci_cpufreq_deregister(host);
1320
1321		mmc_remove_host(host->mmc);
1322		free_irq(host->irq, host);
1323
1324		davinci_release_dma_channels(host);
1325
1326		clk_disable(host->clk);
1327		clk_put(host->clk);
1328
1329		iounmap(host->base);
1330
1331		release_resource(host->mem_res);
1332
1333		mmc_free_host(host->mmc);
1334	}
1335
1336	return 0;
1337}
1338
1339#ifdef CONFIG_PM
1340static int davinci_mmcsd_suspend(struct platform_device *pdev, pm_message_t msg)
1341{
1342	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
1343
1344	return mmc_suspend_host(host->mmc, msg);
1345}
1346
1347static int davinci_mmcsd_resume(struct platform_device *pdev)
1348{
1349	struct mmc_davinci_host *host = platform_get_drvdata(pdev);
1350
1351	return mmc_resume_host(host->mmc);
1352}
1353#else
1354#define davinci_mmcsd_suspend	NULL
1355#define davinci_mmcsd_resume	NULL
1356#endif
1357
1358static struct platform_driver davinci_mmcsd_driver = {
1359	.driver		= {
1360		.name	= "davinci_mmc",
1361		.owner	= THIS_MODULE,
1362	},
1363	.remove		= __exit_p(davinci_mmcsd_remove),
1364	.suspend	= davinci_mmcsd_suspend,
1365	.resume		= davinci_mmcsd_resume,
1366};
1367
1368static int __init davinci_mmcsd_init(void)
1369{
1370	return platform_driver_probe(&davinci_mmcsd_driver,
1371				     davinci_mmcsd_probe);
1372}
1373module_init(davinci_mmcsd_init);
1374
1375static void __exit davinci_mmcsd_exit(void)
1376{
1377	platform_driver_unregister(&davinci_mmcsd_driver);
1378}
1379module_exit(davinci_mmcsd_exit);
1380
1381MODULE_AUTHOR("Texas Instruments India");
1382MODULE_LICENSE("GPL");
1383MODULE_DESCRIPTION("MMC/SD driver for Davinci MMC controller");
1384
1385