xref: /openbmc/u-boot/drivers/mmc/bcm2835_sdhost.c (revision ee943655)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * bcm2835 sdhost driver.
4  *
5  * The 2835 has two SD controllers: The Arasan sdhci controller
6  * (supported by the iproc driver) and a custom sdhost controller
7  * (supported by this driver).
8  *
9  * The sdhci controller supports both sdcard and sdio.  The sdhost
10  * controller supports the sdcard only, but has better performance.
11  * Also note that the rpi3 has sdio wifi, so driving the sdcard with
12  * the sdhost controller allows to use the sdhci controller for wifi
13  * support.
14  *
15  * The configuration is done by devicetree via pin muxing.  Both
16  * SD controller are available on the same pins (2 pin groups = pin 22
17  * to 27 + pin 48 to 53).  So it's possible to use both SD controllers
18  * at the same time with different pin groups.
19  *
20  * This code was ported to U-Boot by
21  *  Alexander Graf <agraf@suse.de>
22  * and is based on drivers/mmc/host/bcm2835.c in Linux which is written by
23  *  Phil Elwell <phil@raspberrypi.org>
24  *  Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
25  * which is based on
26  *  mmc-bcm2835.c by Gellert Weisz
27  * which is, in turn, based on
28  *  sdhci-bcm2708.c by Broadcom
29  *  sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
30  *  sdhci.c and sdhci-pci.c by Pierre Ossman
31  */
32 #include <clk.h>
33 #include <common.h>
34 #include <dm.h>
35 #include <mmc.h>
36 #include <asm/arch/msg.h>
37 #include <asm/arch/mbox.h>
38 #include <asm/unaligned.h>
39 #include <linux/compat.h>
40 #include <linux/io.h>
41 #include <linux/iopoll.h>
42 #include <linux/sizes.h>
43 #include <mach/gpio.h>
44 #include <power/regulator.h>
45 
46 #define msleep(a) udelay(a * 1000)
47 
48 #define SDCMD  0x00 /* Command to SD card              - 16 R/W */
49 #define SDARG  0x04 /* Argument to SD card             - 32 R/W */
50 #define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
51 #define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
52 #define SDRSP0 0x10 /* SD card response (31:0)         - 32 R   */
53 #define SDRSP1 0x14 /* SD card response (63:32)        - 32 R   */
54 #define SDRSP2 0x18 /* SD card response (95:64)        - 32 R   */
55 #define SDRSP3 0x1c /* SD card response (127:96)       - 32 R   */
56 #define SDHSTS 0x20 /* SD host status                  - 11 R/W */
57 #define SDVDD  0x30 /* SD card power control           -  1 R/W */
58 #define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
59 #define SDHCFG 0x38 /* Host configuration              -  2 R/W */
60 #define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
61 #define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
62 #define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
63 
64 #define SDCMD_NEW_FLAG			0x8000
65 #define SDCMD_FAIL_FLAG			0x4000
66 #define SDCMD_BUSYWAIT			0x800
67 #define SDCMD_NO_RESPONSE		0x400
68 #define SDCMD_LONG_RESPONSE		0x200
69 #define SDCMD_WRITE_CMD			0x80
70 #define SDCMD_READ_CMD			0x40
71 #define SDCMD_CMD_MASK			0x3f
72 
73 #define SDCDIV_MAX_CDIV			0x7ff
74 
75 #define SDHSTS_BUSY_IRPT		0x400
76 #define SDHSTS_BLOCK_IRPT		0x200
77 #define SDHSTS_SDIO_IRPT		0x100
78 #define SDHSTS_REW_TIME_OUT		0x80
79 #define SDHSTS_CMD_TIME_OUT		0x40
80 #define SDHSTS_CRC16_ERROR		0x20
81 #define SDHSTS_CRC7_ERROR		0x10
82 #define SDHSTS_FIFO_ERROR		0x08
83 #define SDHSTS_DATA_FLAG		0x01
84 
85 #define SDHSTS_CLEAR_MASK		(SDHSTS_BUSY_IRPT | \
86 					 SDHSTS_BLOCK_IRPT | \
87 					 SDHSTS_SDIO_IRPT | \
88 					 SDHSTS_REW_TIME_OUT | \
89 					 SDHSTS_CMD_TIME_OUT | \
90 					 SDHSTS_CRC16_ERROR | \
91 					 SDHSTS_CRC7_ERROR | \
92 					 SDHSTS_FIFO_ERROR)
93 
94 #define SDHSTS_TRANSFER_ERROR_MASK	(SDHSTS_CRC7_ERROR | \
95 					 SDHSTS_CRC16_ERROR | \
96 					 SDHSTS_REW_TIME_OUT | \
97 					 SDHSTS_FIFO_ERROR)
98 
99 #define SDHSTS_ERROR_MASK		(SDHSTS_CMD_TIME_OUT | \
100 					 SDHSTS_TRANSFER_ERROR_MASK)
101 
102 #define SDHCFG_BUSY_IRPT_EN	BIT(10)
103 #define SDHCFG_BLOCK_IRPT_EN	BIT(8)
104 #define SDHCFG_SDIO_IRPT_EN	BIT(5)
105 #define SDHCFG_DATA_IRPT_EN	BIT(4)
106 #define SDHCFG_SLOW_CARD	BIT(3)
107 #define SDHCFG_WIDE_EXT_BUS	BIT(2)
108 #define SDHCFG_WIDE_INT_BUS	BIT(1)
109 #define SDHCFG_REL_CMD_LINE	BIT(0)
110 
111 #define SDVDD_POWER_OFF		0
112 #define SDVDD_POWER_ON		1
113 
114 #define SDEDM_FORCE_DATA_MODE	BIT(19)
115 #define SDEDM_CLOCK_PULSE	BIT(20)
116 #define SDEDM_BYPASS		BIT(21)
117 
118 #define SDEDM_FIFO_FILL_SHIFT	4
119 #define SDEDM_FIFO_FILL_MASK	0x1f
120 static u32 edm_fifo_fill(u32 edm)
121 {
122 	return (edm >> SDEDM_FIFO_FILL_SHIFT) & SDEDM_FIFO_FILL_MASK;
123 }
124 
125 #define SDEDM_WRITE_THRESHOLD_SHIFT	9
126 #define SDEDM_READ_THRESHOLD_SHIFT	14
127 #define SDEDM_THRESHOLD_MASK		0x1f
128 
129 #define SDEDM_FSM_MASK		0xf
130 #define SDEDM_FSM_IDENTMODE	0x0
131 #define SDEDM_FSM_DATAMODE	0x1
132 #define SDEDM_FSM_READDATA	0x2
133 #define SDEDM_FSM_WRITEDATA	0x3
134 #define SDEDM_FSM_READWAIT	0x4
135 #define SDEDM_FSM_READCRC	0x5
136 #define SDEDM_FSM_WRITECRC	0x6
137 #define SDEDM_FSM_WRITEWAIT1	0x7
138 #define SDEDM_FSM_POWERDOWN	0x8
139 #define SDEDM_FSM_POWERUP	0x9
140 #define SDEDM_FSM_WRITESTART1	0xa
141 #define SDEDM_FSM_WRITESTART2	0xb
142 #define SDEDM_FSM_GENPULSES	0xc
143 #define SDEDM_FSM_WRITEWAIT2	0xd
144 #define SDEDM_FSM_STARTPOWDOWN	0xf
145 
146 #define SDDATA_FIFO_WORDS	16
147 
148 #define FIFO_READ_THRESHOLD	4
149 #define FIFO_WRITE_THRESHOLD	4
150 #define SDDATA_FIFO_PIO_BURST	8
151 
152 #define SDHST_TIMEOUT_MAX_USEC	100000
153 
154 struct bcm2835_plat {
155 	struct mmc_config cfg;
156 	struct mmc mmc;
157 };
158 
159 struct bcm2835_host {
160 	void __iomem		*ioaddr;
161 	u32			phys_addr;
162 
163 	int			clock;		/* Current clock speed */
164 	unsigned int		max_clk;	/* Max possible freq */
165 	unsigned int		blocks;		/* remaining PIO blocks */
166 	int			irq;		/* Device IRQ */
167 
168 	u32			ns_per_fifo_word;
169 
170 	/* cached registers */
171 	u32			hcfg;
172 	u32			cdiv;
173 
174 	struct mmc_cmd	*cmd;		/* Current command */
175 	struct mmc_data		*data;		/* Current data request */
176 	bool			data_complete:1;/* Data finished before cmd */
177 	bool			use_busy:1;	/* Wait for busy interrupt */
178 	bool			wait_data_complete:1;	/* Wait for data */
179 
180 	/* for threaded irq handler */
181 	bool			irq_block;
182 	bool			irq_busy;
183 	bool			irq_data;
184 
185 	struct udevice		*dev;
186 	struct mmc		*mmc;
187 	struct bcm2835_plat	*plat;
188 };
189 
190 static void bcm2835_dumpregs(struct bcm2835_host *host)
191 {
192 	dev_dbg(dev, "=========== REGISTER DUMP ===========\n");
193 	dev_dbg(dev, "SDCMD  0x%08x\n", readl(host->ioaddr + SDCMD));
194 	dev_dbg(dev, "SDARG  0x%08x\n", readl(host->ioaddr + SDARG));
195 	dev_dbg(dev, "SDTOUT 0x%08x\n", readl(host->ioaddr + SDTOUT));
196 	dev_dbg(dev, "SDCDIV 0x%08x\n", readl(host->ioaddr + SDCDIV));
197 	dev_dbg(dev, "SDRSP0 0x%08x\n", readl(host->ioaddr + SDRSP0));
198 	dev_dbg(dev, "SDRSP1 0x%08x\n", readl(host->ioaddr + SDRSP1));
199 	dev_dbg(dev, "SDRSP2 0x%08x\n", readl(host->ioaddr + SDRSP2));
200 	dev_dbg(dev, "SDRSP3 0x%08x\n", readl(host->ioaddr + SDRSP3));
201 	dev_dbg(dev, "SDHSTS 0x%08x\n", readl(host->ioaddr + SDHSTS));
202 	dev_dbg(dev, "SDVDD  0x%08x\n", readl(host->ioaddr + SDVDD));
203 	dev_dbg(dev, "SDEDM  0x%08x\n", readl(host->ioaddr + SDEDM));
204 	dev_dbg(dev, "SDHCFG 0x%08x\n", readl(host->ioaddr + SDHCFG));
205 	dev_dbg(dev, "SDHBCT 0x%08x\n", readl(host->ioaddr + SDHBCT));
206 	dev_dbg(dev, "SDHBLC 0x%08x\n", readl(host->ioaddr + SDHBLC));
207 	dev_dbg(dev, "===========================================\n");
208 }
209 
210 static void bcm2835_reset_internal(struct bcm2835_host *host)
211 {
212 	u32 temp;
213 
214 	writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
215 	writel(0, host->ioaddr + SDCMD);
216 	writel(0, host->ioaddr + SDARG);
217 	/* Set timeout to a big enough value so we don't hit it */
218 	writel(0xf00000, host->ioaddr + SDTOUT);
219 	writel(0, host->ioaddr + SDCDIV);
220 	/* Clear status register */
221 	writel(SDHSTS_CLEAR_MASK, host->ioaddr + SDHSTS);
222 	writel(0, host->ioaddr + SDHCFG);
223 	writel(0, host->ioaddr + SDHBCT);
224 	writel(0, host->ioaddr + SDHBLC);
225 
226 	/* Limit fifo usage due to silicon bug */
227 	temp = readl(host->ioaddr + SDEDM);
228 	temp &= ~((SDEDM_THRESHOLD_MASK << SDEDM_READ_THRESHOLD_SHIFT) |
229 		  (SDEDM_THRESHOLD_MASK << SDEDM_WRITE_THRESHOLD_SHIFT));
230 	temp |= (FIFO_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) |
231 		(FIFO_WRITE_THRESHOLD << SDEDM_WRITE_THRESHOLD_SHIFT);
232 	writel(temp, host->ioaddr + SDEDM);
233 	/* Wait for FIFO threshold to populate */
234 	msleep(20);
235 	writel(SDVDD_POWER_ON, host->ioaddr + SDVDD);
236 	/* Wait for all components to go through power on cycle */
237 	msleep(20);
238 	host->clock = 0;
239 	writel(host->hcfg, host->ioaddr + SDHCFG);
240 	writel(host->cdiv, host->ioaddr + SDCDIV);
241 }
242 
243 static int bcm2835_finish_command(struct bcm2835_host *host);
244 
245 static void bcm2835_wait_transfer_complete(struct bcm2835_host *host)
246 {
247 	int timediff;
248 	u32 alternate_idle;
249 
250 	alternate_idle = (host->data->flags & MMC_DATA_READ) ?
251 		SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1;
252 
253 	timediff = 0;
254 
255 	while (1) {
256 		u32 edm, fsm;
257 
258 		edm = readl(host->ioaddr + SDEDM);
259 		fsm = edm & SDEDM_FSM_MASK;
260 
261 		if ((fsm == SDEDM_FSM_IDENTMODE) ||
262 		    (fsm == SDEDM_FSM_DATAMODE))
263 			break;
264 		if (fsm == alternate_idle) {
265 			writel(edm | SDEDM_FORCE_DATA_MODE,
266 			       host->ioaddr + SDEDM);
267 			break;
268 		}
269 
270 		/* Error out after 100000 register reads (~1s) */
271 		if (timediff++ == 100000) {
272 			dev_err(host->dev,
273 				"wait_transfer_complete - still waiting after %d retries\n",
274 				timediff);
275 			bcm2835_dumpregs(host);
276 			return;
277 		}
278 	}
279 }
280 
281 static int bcm2835_transfer_block_pio(struct bcm2835_host *host, bool is_read)
282 {
283 	struct mmc_data *data = host->data;
284 	size_t blksize = data->blocksize;
285 	int copy_words;
286 	u32 hsts = 0;
287 	u32 *buf;
288 
289 	if (blksize % sizeof(u32))
290 		return -EINVAL;
291 
292 	buf = is_read ? (u32 *)data->dest : (u32 *)data->src;
293 
294 	if (is_read)
295 		data->dest += blksize;
296 	else
297 		data->src += blksize;
298 
299 	copy_words = blksize / sizeof(u32);
300 
301 	/*
302 	 * Copy all contents from/to the FIFO as far as it reaches,
303 	 * then wait for it to fill/empty again and rewind.
304 	 */
305 	while (copy_words) {
306 		int burst_words, words;
307 		u32 edm;
308 
309 		burst_words = min(SDDATA_FIFO_PIO_BURST, copy_words);
310 		edm = readl(host->ioaddr + SDEDM);
311 		if (is_read)
312 			words = edm_fifo_fill(edm);
313 		else
314 			words = SDDATA_FIFO_WORDS - edm_fifo_fill(edm);
315 
316 		if (words < burst_words) {
317 			int fsm_state = (edm & SDEDM_FSM_MASK);
318 
319 			if ((is_read &&
320 			     (fsm_state != SDEDM_FSM_READDATA &&
321 			      fsm_state != SDEDM_FSM_READWAIT &&
322 			      fsm_state != SDEDM_FSM_READCRC)) ||
323 			    (!is_read &&
324 			     (fsm_state != SDEDM_FSM_WRITEDATA &&
325 			      fsm_state != SDEDM_FSM_WRITESTART1 &&
326 			      fsm_state != SDEDM_FSM_WRITESTART2))) {
327 				hsts = readl(host->ioaddr + SDHSTS);
328 				printf("fsm %x, hsts %08x\n", fsm_state, hsts);
329 				if (hsts & SDHSTS_ERROR_MASK)
330 					break;
331 			}
332 
333 			continue;
334 		} else if (words > copy_words) {
335 			words = copy_words;
336 		}
337 
338 		copy_words -= words;
339 
340 		/* Copy current chunk to/from the FIFO */
341 		while (words) {
342 			if (is_read)
343 				*(buf++) = readl(host->ioaddr + SDDATA);
344 			else
345 				writel(*(buf++), host->ioaddr + SDDATA);
346 			words--;
347 		}
348 	}
349 
350 	return 0;
351 }
352 
353 static int bcm2835_transfer_pio(struct bcm2835_host *host)
354 {
355 	u32 sdhsts;
356 	bool is_read;
357 	int ret = 0;
358 
359 	is_read = (host->data->flags & MMC_DATA_READ) != 0;
360 	ret = bcm2835_transfer_block_pio(host, is_read);
361 
362 	if (host->wait_data_complete)
363 		bcm2835_wait_transfer_complete(host);
364 
365 	sdhsts = readl(host->ioaddr + SDHSTS);
366 	if (sdhsts & (SDHSTS_CRC16_ERROR |
367 		      SDHSTS_CRC7_ERROR |
368 		      SDHSTS_FIFO_ERROR)) {
369 		printf("%s transfer error - HSTS %08x\n",
370 		       is_read ? "read" : "write", sdhsts);
371 		ret =  -EILSEQ;
372 	} else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
373 			      SDHSTS_REW_TIME_OUT))) {
374 		printf("%s timeout error - HSTS %08x\n",
375 		       is_read ? "read" : "write", sdhsts);
376 		ret = -ETIMEDOUT;
377 	}
378 
379 	return ret;
380 }
381 
382 static void bcm2835_set_transfer_irqs(struct bcm2835_host *host)
383 {
384 	u32 all_irqs = SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN |
385 		SDHCFG_BUSY_IRPT_EN;
386 
387 	host->hcfg = (host->hcfg & ~all_irqs) |
388 		SDHCFG_DATA_IRPT_EN |
389 		SDHCFG_BUSY_IRPT_EN;
390 
391 	writel(host->hcfg, host->ioaddr + SDHCFG);
392 }
393 
394 static
395 void bcm2835_prepare_data(struct bcm2835_host *host, struct mmc_cmd *cmd,
396 			  struct mmc_data *data)
397 {
398 	WARN_ON(host->data);
399 
400 	host->data = data;
401 	if (!data)
402 		return;
403 
404 	host->wait_data_complete = cmd->cmdidx != MMC_CMD_READ_MULTIPLE_BLOCK;
405 	host->data_complete = false;
406 
407 	/* Use PIO */
408 	host->blocks = data->blocks;
409 
410 	bcm2835_set_transfer_irqs(host);
411 
412 	writel(data->blocksize, host->ioaddr + SDHBCT);
413 	writel(data->blocks, host->ioaddr + SDHBLC);
414 }
415 
416 static u32 bcm2835_read_wait_sdcmd(struct bcm2835_host *host)
417 {
418 	u32 value;
419 	int ret;
420 	int timeout_us = SDHST_TIMEOUT_MAX_USEC;
421 
422 	ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
423 				 !(value & SDCMD_NEW_FLAG), timeout_us);
424 	if (ret == -ETIMEDOUT)
425 		printf("%s: timeout (%d us)\n", __func__, timeout_us);
426 
427 	return value;
428 }
429 
430 static int bcm2835_send_command(struct bcm2835_host *host, struct mmc_cmd *cmd,
431 				struct mmc_data *data)
432 {
433 	u32 sdcmd, sdhsts;
434 
435 	WARN_ON(host->cmd);
436 
437 	if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY)) {
438 		printf("unsupported response type!\n");
439 		return -EINVAL;
440 	}
441 
442 	sdcmd = bcm2835_read_wait_sdcmd(host);
443 	if (sdcmd & SDCMD_NEW_FLAG) {
444 		printf("previous command never completed.\n");
445 		bcm2835_dumpregs(host);
446 		return -EBUSY;
447 	}
448 
449 	host->cmd = cmd;
450 
451 	/* Clear any error flags */
452 	sdhsts = readl(host->ioaddr + SDHSTS);
453 	if (sdhsts & SDHSTS_ERROR_MASK)
454 		writel(sdhsts, host->ioaddr + SDHSTS);
455 
456 	bcm2835_prepare_data(host, cmd, data);
457 
458 	writel(cmd->cmdarg, host->ioaddr + SDARG);
459 
460 	sdcmd = cmd->cmdidx & SDCMD_CMD_MASK;
461 
462 	host->use_busy = false;
463 	if (!(cmd->resp_type & MMC_RSP_PRESENT)) {
464 		sdcmd |= SDCMD_NO_RESPONSE;
465 	} else {
466 		if (cmd->resp_type & MMC_RSP_136)
467 			sdcmd |= SDCMD_LONG_RESPONSE;
468 		if (cmd->resp_type & MMC_RSP_BUSY) {
469 			sdcmd |= SDCMD_BUSYWAIT;
470 			host->use_busy = true;
471 		}
472 	}
473 
474 	if (data) {
475 		if (data->flags & MMC_DATA_WRITE)
476 			sdcmd |= SDCMD_WRITE_CMD;
477 		if (data->flags & MMC_DATA_READ)
478 			sdcmd |= SDCMD_READ_CMD;
479 	}
480 
481 	writel(sdcmd | SDCMD_NEW_FLAG, host->ioaddr + SDCMD);
482 
483 	return 0;
484 }
485 
486 static int bcm2835_transfer_complete(struct bcm2835_host *host)
487 {
488 	int ret = 0;
489 
490 	WARN_ON(!host->data_complete);
491 
492 	host->data = NULL;
493 
494 	return ret;
495 }
496 
497 static void bcm2835_finish_data(struct bcm2835_host *host)
498 {
499 	host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
500 	writel(host->hcfg, host->ioaddr + SDHCFG);
501 
502 	host->data_complete = true;
503 
504 	if (host->cmd) {
505 		/* Data managed to finish before the
506 		 * command completed. Make sure we do
507 		 * things in the proper order.
508 		 */
509 		dev_dbg(dev, "Finished early - HSTS %08x\n",
510 			readl(host->ioaddr + SDHSTS));
511 	} else {
512 		bcm2835_transfer_complete(host);
513 	}
514 }
515 
516 static int bcm2835_finish_command(struct bcm2835_host *host)
517 {
518 	struct mmc_cmd *cmd = host->cmd;
519 	u32 sdcmd;
520 	int ret = 0;
521 
522 	sdcmd = bcm2835_read_wait_sdcmd(host);
523 
524 	/* Check for errors */
525 	if (sdcmd & SDCMD_NEW_FLAG) {
526 		printf("command never completed.\n");
527 		bcm2835_dumpregs(host);
528 		return -EIO;
529 	} else if (sdcmd & SDCMD_FAIL_FLAG) {
530 		u32 sdhsts = readl(host->ioaddr + SDHSTS);
531 
532 		/* Clear the errors */
533 		writel(SDHSTS_ERROR_MASK, host->ioaddr + SDHSTS);
534 
535 		if (!(sdhsts & SDHSTS_CRC7_ERROR) ||
536 		    (host->cmd->cmdidx != MMC_CMD_SEND_OP_COND)) {
537 			if (sdhsts & SDHSTS_CMD_TIME_OUT) {
538 				ret = -ETIMEDOUT;
539 			} else {
540 				printf("unexpected command %d error\n",
541 				       host->cmd->cmdidx);
542 				bcm2835_dumpregs(host);
543 				ret = -EILSEQ;
544 			}
545 
546 			return ret;
547 		}
548 	}
549 
550 	if (cmd->resp_type & MMC_RSP_PRESENT) {
551 		if (cmd->resp_type & MMC_RSP_136) {
552 			int i;
553 
554 			for (i = 0; i < 4; i++) {
555 				cmd->response[3 - i] =
556 					readl(host->ioaddr + SDRSP0 + i * 4);
557 			}
558 		} else {
559 			cmd->response[0] = readl(host->ioaddr + SDRSP0);
560 		}
561 	}
562 
563 	/* Processed actual command. */
564 	host->cmd = NULL;
565 	if (host->data && host->data_complete)
566 		ret = bcm2835_transfer_complete(host);
567 
568 	return ret;
569 }
570 
571 static int bcm2835_check_cmd_error(struct bcm2835_host *host, u32 intmask)
572 {
573 	int ret = -EINVAL;
574 
575 	if (!(intmask & SDHSTS_ERROR_MASK))
576 		return 0;
577 
578 	if (!host->cmd)
579 		return -EINVAL;
580 
581 	printf("sdhost_busy_irq: intmask %08x\n", intmask);
582 	if (intmask & SDHSTS_CRC7_ERROR) {
583 		ret = -EILSEQ;
584 	} else if (intmask & (SDHSTS_CRC16_ERROR |
585 			      SDHSTS_FIFO_ERROR)) {
586 		ret = -EILSEQ;
587 	} else if (intmask & (SDHSTS_REW_TIME_OUT | SDHSTS_CMD_TIME_OUT)) {
588 		ret = -ETIMEDOUT;
589 	}
590 	bcm2835_dumpregs(host);
591 	return ret;
592 }
593 
594 static int bcm2835_check_data_error(struct bcm2835_host *host, u32 intmask)
595 {
596 	int ret = 0;
597 
598 	if (!host->data)
599 		return 0;
600 	if (intmask & (SDHSTS_CRC16_ERROR | SDHSTS_FIFO_ERROR))
601 		ret = -EILSEQ;
602 	if (intmask & SDHSTS_REW_TIME_OUT)
603 		ret = -ETIMEDOUT;
604 
605 	if (ret)
606 		printf("%s:%d %d\n", __func__, __LINE__, ret);
607 
608 	return ret;
609 }
610 
611 static void bcm2835_busy_irq(struct bcm2835_host *host)
612 {
613 	if (WARN_ON(!host->cmd)) {
614 		bcm2835_dumpregs(host);
615 		return;
616 	}
617 
618 	if (WARN_ON(!host->use_busy)) {
619 		bcm2835_dumpregs(host);
620 		return;
621 	}
622 	host->use_busy = false;
623 
624 	bcm2835_finish_command(host);
625 }
626 
627 static void bcm2835_data_irq(struct bcm2835_host *host, u32 intmask)
628 {
629 	int ret;
630 
631 	/*
632 	 * There are no dedicated data/space available interrupt
633 	 * status bits, so it is necessary to use the single shared
634 	 * data/space available FIFO status bits. It is therefore not
635 	 * an error to get here when there is no data transfer in
636 	 * progress.
637 	 */
638 	if (!host->data)
639 		return;
640 
641 	ret = bcm2835_check_data_error(host, intmask);
642 	if (ret)
643 		goto finished;
644 
645 	if (host->data->flags & MMC_DATA_WRITE) {
646 		/* Use the block interrupt for writes after the first block */
647 		host->hcfg &= ~(SDHCFG_DATA_IRPT_EN);
648 		host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
649 		writel(host->hcfg, host->ioaddr + SDHCFG);
650 		bcm2835_transfer_pio(host);
651 	} else {
652 		bcm2835_transfer_pio(host);
653 		host->blocks--;
654 		if ((host->blocks == 0))
655 			goto finished;
656 	}
657 	return;
658 
659 finished:
660 	host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
661 	writel(host->hcfg, host->ioaddr + SDHCFG);
662 }
663 
664 static void bcm2835_data_threaded_irq(struct bcm2835_host *host)
665 {
666 	if (!host->data)
667 		return;
668 	if ((host->blocks == 0))
669 		bcm2835_finish_data(host);
670 }
671 
672 static void bcm2835_block_irq(struct bcm2835_host *host)
673 {
674 	if (WARN_ON(!host->data)) {
675 		bcm2835_dumpregs(host);
676 		return;
677 	}
678 
679 	WARN_ON(!host->blocks);
680 	if ((--host->blocks == 0))
681 		bcm2835_finish_data(host);
682 	else
683 		bcm2835_transfer_pio(host);
684 }
685 
686 static irqreturn_t bcm2835_irq(int irq, void *dev_id)
687 {
688 	irqreturn_t result = IRQ_NONE;
689 	struct bcm2835_host *host = dev_id;
690 	u32 intmask;
691 
692 	intmask = readl(host->ioaddr + SDHSTS);
693 
694 	writel(SDHSTS_BUSY_IRPT |
695 	       SDHSTS_BLOCK_IRPT |
696 	       SDHSTS_SDIO_IRPT |
697 	       SDHSTS_DATA_FLAG,
698 	       host->ioaddr + SDHSTS);
699 
700 	if (intmask & SDHSTS_BLOCK_IRPT) {
701 		bcm2835_check_data_error(host, intmask);
702 		host->irq_block = true;
703 		result = IRQ_WAKE_THREAD;
704 	}
705 
706 	if (intmask & SDHSTS_BUSY_IRPT) {
707 		if (!bcm2835_check_cmd_error(host, intmask)) {
708 			host->irq_busy = true;
709 			result = IRQ_WAKE_THREAD;
710 		} else {
711 			result = IRQ_HANDLED;
712 		}
713 	}
714 
715 	/* There is no true data interrupt status bit, so it is
716 	 * necessary to qualify the data flag with the interrupt
717 	 * enable bit.
718 	 */
719 	if ((intmask & SDHSTS_DATA_FLAG) &&
720 	    (host->hcfg & SDHCFG_DATA_IRPT_EN)) {
721 		bcm2835_data_irq(host, intmask);
722 		host->irq_data = true;
723 		result = IRQ_WAKE_THREAD;
724 	}
725 
726 	return result;
727 }
728 
729 static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id)
730 {
731 	struct bcm2835_host *host = dev_id;
732 
733 	if (host->irq_block) {
734 		host->irq_block = false;
735 		bcm2835_block_irq(host);
736 	}
737 
738 	if (host->irq_busy) {
739 		host->irq_busy = false;
740 		bcm2835_busy_irq(host);
741 	}
742 
743 	if (host->irq_data) {
744 		host->irq_data = false;
745 		bcm2835_data_threaded_irq(host);
746 	}
747 
748 	return IRQ_HANDLED;
749 }
750 
751 static void bcm2835_irq_poll(struct bcm2835_host *host)
752 {
753 	u32 intmask;
754 
755 	while (1) {
756 		intmask = readl(host->ioaddr + SDHSTS);
757 		if (intmask & (SDHSTS_BUSY_IRPT | SDHSTS_BLOCK_IRPT |
758 			       SDHSTS_SDIO_IRPT | SDHSTS_DATA_FLAG)) {
759 			bcm2835_irq(0, host);
760 			bcm2835_threaded_irq(0, host);
761 			return;
762 		}
763 	}
764 }
765 
766 static void bcm2835_set_clock(struct bcm2835_host *host, unsigned int clock)
767 {
768 	int div;
769 
770 	/* The SDCDIV register has 11 bits, and holds (div - 2).  But
771 	 * in data mode the max is 50MHz wihout a minimum, and only
772 	 * the bottom 3 bits are used. Since the switch over is
773 	 * automatic (unless we have marked the card as slow...),
774 	 * chosen values have to make sense in both modes.  Ident mode
775 	 * must be 100-400KHz, so can range check the requested
776 	 * clock. CMD15 must be used to return to data mode, so this
777 	 * can be monitored.
778 	 *
779 	 * clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz
780 	 *                 4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz
781 	 *
782 	 *		 623->400KHz/27.8MHz
783 	 *		 reset value (507)->491159/50MHz
784 	 *
785 	 * BUT, the 3-bit clock divisor in data mode is too small if
786 	 * the core clock is higher than 250MHz, so instead use the
787 	 * SLOW_CARD configuration bit to force the use of the ident
788 	 * clock divisor at all times.
789 	 */
790 
791 	if (clock < 100000) {
792 		/* Can't stop the clock, but make it as slow as possible
793 		 * to show willing
794 		 */
795 		host->cdiv = SDCDIV_MAX_CDIV;
796 		writel(host->cdiv, host->ioaddr + SDCDIV);
797 		return;
798 	}
799 
800 	div = host->max_clk / clock;
801 	if (div < 2)
802 		div = 2;
803 	if ((host->max_clk / div) > clock)
804 		div++;
805 	div -= 2;
806 
807 	if (div > SDCDIV_MAX_CDIV)
808 		div = SDCDIV_MAX_CDIV;
809 
810 	clock = host->max_clk / (div + 2);
811 	host->mmc->clock = clock;
812 
813 	/* Calibrate some delays */
814 
815 	host->ns_per_fifo_word = (1000000000 / clock) *
816 		((host->mmc->card_caps & MMC_MODE_4BIT) ? 8 : 32);
817 
818 	host->cdiv = div;
819 	writel(host->cdiv, host->ioaddr + SDCDIV);
820 
821 	/* Set the timeout to 500ms */
822 	writel(host->mmc->clock / 2, host->ioaddr + SDTOUT);
823 }
824 
825 static inline int is_power_of_2(u64 x)
826 {
827 	return !(x & (x - 1));
828 }
829 
830 static int bcm2835_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
831 			    struct mmc_data *data)
832 {
833 	struct bcm2835_host *host = dev_get_priv(dev);
834 	u32 edm, fsm;
835 	int ret = 0;
836 
837 	if (data && !is_power_of_2(data->blocksize)) {
838 		printf("unsupported block size (%d bytes)\n", data->blocksize);
839 
840 		if (cmd)
841 			return -EINVAL;
842 	}
843 
844 	edm = readl(host->ioaddr + SDEDM);
845 	fsm = edm & SDEDM_FSM_MASK;
846 
847 	if ((fsm != SDEDM_FSM_IDENTMODE) &&
848 	    (fsm != SDEDM_FSM_DATAMODE) &&
849 	    (cmd && cmd->cmdidx != MMC_CMD_STOP_TRANSMISSION)) {
850 		printf("previous command (%d) not complete (EDM %08x)\n",
851 		       readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK, edm);
852 		bcm2835_dumpregs(host);
853 
854 		if (cmd)
855 			return -EILSEQ;
856 
857 		return 0;
858 	}
859 
860 	if (cmd) {
861 		ret = bcm2835_send_command(host, cmd, data);
862 		if (!ret && !host->use_busy)
863 			ret = bcm2835_finish_command(host);
864 	}
865 
866 	/* Wait for completion of busy signal or data transfer */
867 	while (host->use_busy || host->data)
868 		bcm2835_irq_poll(host);
869 
870 	return ret;
871 }
872 
873 static int bcm2835_set_ios(struct udevice *dev)
874 {
875 	struct bcm2835_host *host = dev_get_priv(dev);
876 	struct mmc *mmc = mmc_get_mmc_dev(dev);
877 
878 	if (!mmc->clock || mmc->clock != host->clock) {
879 		bcm2835_set_clock(host, mmc->clock);
880 		host->clock = mmc->clock;
881 	}
882 
883 	/* set bus width */
884 	host->hcfg &= ~SDHCFG_WIDE_EXT_BUS;
885 	if (mmc->bus_width == 4)
886 		host->hcfg |= SDHCFG_WIDE_EXT_BUS;
887 
888 	host->hcfg |= SDHCFG_WIDE_INT_BUS;
889 
890 	/* Disable clever clock switching, to cope with fast core clocks */
891 	host->hcfg |= SDHCFG_SLOW_CARD;
892 
893 	writel(host->hcfg, host->ioaddr + SDHCFG);
894 
895 	return 0;
896 }
897 
898 static void bcm2835_add_host(struct bcm2835_host *host)
899 {
900 	struct mmc_config *cfg = &host->plat->cfg;
901 
902 	cfg->f_max = host->max_clk;
903 	cfg->f_min = host->max_clk / SDCDIV_MAX_CDIV;
904 	cfg->b_max = 65535;
905 
906 	dev_dbg(dev, "f_max %d, f_min %d\n",
907 		cfg->f_max, cfg->f_min);
908 
909 	/* host controller capabilities */
910 	cfg->host_caps = MMC_MODE_4BIT | MMC_MODE_HS | MMC_MODE_HS_52MHz;
911 
912 	/* report supported voltage ranges */
913 	cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
914 
915 	/* Set interrupt enables */
916 	host->hcfg = SDHCFG_BUSY_IRPT_EN;
917 
918 	bcm2835_reset_internal(host);
919 }
920 
921 static int bcm2835_probe(struct udevice *dev)
922 {
923 	struct bcm2835_plat *plat = dev_get_platdata(dev);
924 	struct bcm2835_host *host = dev_get_priv(dev);
925 	struct mmc *mmc = mmc_get_mmc_dev(dev);
926 	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
927 
928 	host->dev = dev;
929 	host->mmc = mmc;
930 	host->plat = plat;
931 	upriv->mmc = &plat->mmc;
932 	plat->cfg.name = dev->name;
933 
934 	host->phys_addr = devfdt_get_addr(dev);
935 	if (host->phys_addr == FDT_ADDR_T_NONE)
936 		return -EINVAL;
937 
938 	host->ioaddr = devm_ioremap(dev, host->phys_addr, SZ_256);
939 	if (!host->ioaddr)
940 		return -ENOMEM;
941 
942 	host->max_clk = bcm2835_get_mmc_clock(BCM2835_MBOX_CLOCK_ID_CORE);
943 
944 	bcm2835_add_host(host);
945 
946 	dev_dbg(dev, "%s -> OK\n", __func__);
947 
948 	return 0;
949 }
950 
951 static const struct udevice_id bcm2835_match[] = {
952 	{ .compatible = "brcm,bcm2835-sdhost" },
953 	{ }
954 };
955 
956 static const struct dm_mmc_ops bcm2835_ops = {
957 	.send_cmd = bcm2835_send_cmd,
958 	.set_ios = bcm2835_set_ios,
959 };
960 
961 static int bcm2835_bind(struct udevice *dev)
962 {
963 	struct bcm2835_plat *plat = dev_get_platdata(dev);
964 
965 	return mmc_bind(dev, &plat->mmc, &plat->cfg);
966 }
967 
968 U_BOOT_DRIVER(bcm2835_sdhost) = {
969 	.name = "bcm2835-sdhost",
970 	.id = UCLASS_MMC,
971 	.of_match = bcm2835_match,
972 	.bind = bcm2835_bind,
973 	.probe = bcm2835_probe,
974 	.priv_auto_alloc_size = sizeof(struct bcm2835_host),
975 	.platdata_auto_alloc_size = sizeof(struct bcm2835_plat),
976 	.ops = &bcm2835_ops,
977 };
978