xref: /openbmc/u-boot/drivers/mmc/bcm2835_sdhost.c (revision 1f154a63)
1 /*
2  * bcm2835 sdhost driver.
3  *
4  * The 2835 has two SD controllers: The Arasan sdhci controller
5  * (supported by the iproc driver) and a custom sdhost controller
6  * (supported by this driver).
7  *
8  * The sdhci controller supports both sdcard and sdio.  The sdhost
9  * controller supports the sdcard only, but has better performance.
10  * Also note that the rpi3 has sdio wifi, so driving the sdcard with
11  * the sdhost controller allows to use the sdhci controller for wifi
12  * support.
13  *
14  * The configuration is done by devicetree via pin muxing.  Both
15  * SD controller are available on the same pins (2 pin groups = pin 22
16  * to 27 + pin 48 to 53).  So it's possible to use both SD controllers
17  * at the same time with different pin groups.
18  *
19  * This code was ported to U-Boot by
20  *  Alexander Graf <agraf@suse.de>
21  * and is based on drivers/mmc/host/bcm2835.c in Linux which is written by
22  *  Phil Elwell <phil@raspberrypi.org>
23  *  Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
24  * which is based on
25  *  mmc-bcm2835.c by Gellert Weisz
26  * which is, in turn, based on
27  *  sdhci-bcm2708.c by Broadcom
28  *  sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
29  *  sdhci.c and sdhci-pci.c by Pierre Ossman
30  *
31  * SPDX-License-Identifier:    GPL-2.0
32  */
33 #include <clk.h>
34 #include <common.h>
35 #include <dm.h>
36 #include <mmc.h>
37 #include <asm/arch/msg.h>
38 #include <asm/arch/mbox.h>
39 #include <asm/unaligned.h>
40 #include <linux/compat.h>
41 #include <linux/io.h>
42 #include <linux/iopoll.h>
43 #include <linux/sizes.h>
44 #include <mach/gpio.h>
45 #include <power/regulator.h>
46 
47 #define msleep(a) udelay(a * 1000)
48 
49 #define SDCMD  0x00 /* Command to SD card              - 16 R/W */
50 #define SDARG  0x04 /* Argument to SD card             - 32 R/W */
51 #define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
52 #define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
53 #define SDRSP0 0x10 /* SD card response (31:0)         - 32 R   */
54 #define SDRSP1 0x14 /* SD card response (63:32)        - 32 R   */
55 #define SDRSP2 0x18 /* SD card response (95:64)        - 32 R   */
56 #define SDRSP3 0x1c /* SD card response (127:96)       - 32 R   */
57 #define SDHSTS 0x20 /* SD host status                  - 11 R/W */
58 #define SDVDD  0x30 /* SD card power control           -  1 R/W */
59 #define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
60 #define SDHCFG 0x38 /* Host configuration              -  2 R/W */
61 #define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
62 #define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
63 #define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
64 
65 #define SDCMD_NEW_FLAG			0x8000
66 #define SDCMD_FAIL_FLAG			0x4000
67 #define SDCMD_BUSYWAIT			0x800
68 #define SDCMD_NO_RESPONSE		0x400
69 #define SDCMD_LONG_RESPONSE		0x200
70 #define SDCMD_WRITE_CMD			0x80
71 #define SDCMD_READ_CMD			0x40
72 #define SDCMD_CMD_MASK			0x3f
73 
74 #define SDCDIV_MAX_CDIV			0x7ff
75 
76 #define SDHSTS_BUSY_IRPT		0x400
77 #define SDHSTS_BLOCK_IRPT		0x200
78 #define SDHSTS_SDIO_IRPT		0x100
79 #define SDHSTS_REW_TIME_OUT		0x80
80 #define SDHSTS_CMD_TIME_OUT		0x40
81 #define SDHSTS_CRC16_ERROR		0x20
82 #define SDHSTS_CRC7_ERROR		0x10
83 #define SDHSTS_FIFO_ERROR		0x08
84 #define SDHSTS_DATA_FLAG		0x01
85 
86 #define SDHSTS_CLEAR_MASK		(SDHSTS_BUSY_IRPT | \
87 					 SDHSTS_BLOCK_IRPT | \
88 					 SDHSTS_SDIO_IRPT | \
89 					 SDHSTS_REW_TIME_OUT | \
90 					 SDHSTS_CMD_TIME_OUT | \
91 					 SDHSTS_CRC16_ERROR | \
92 					 SDHSTS_CRC7_ERROR | \
93 					 SDHSTS_FIFO_ERROR)
94 
95 #define SDHSTS_TRANSFER_ERROR_MASK	(SDHSTS_CRC7_ERROR | \
96 					 SDHSTS_CRC16_ERROR | \
97 					 SDHSTS_REW_TIME_OUT | \
98 					 SDHSTS_FIFO_ERROR)
99 
100 #define SDHSTS_ERROR_MASK		(SDHSTS_CMD_TIME_OUT | \
101 					 SDHSTS_TRANSFER_ERROR_MASK)
102 
103 #define SDHCFG_BUSY_IRPT_EN	BIT(10)
104 #define SDHCFG_BLOCK_IRPT_EN	BIT(8)
105 #define SDHCFG_SDIO_IRPT_EN	BIT(5)
106 #define SDHCFG_DATA_IRPT_EN	BIT(4)
107 #define SDHCFG_SLOW_CARD	BIT(3)
108 #define SDHCFG_WIDE_EXT_BUS	BIT(2)
109 #define SDHCFG_WIDE_INT_BUS	BIT(1)
110 #define SDHCFG_REL_CMD_LINE	BIT(0)
111 
112 #define SDVDD_POWER_OFF		0
113 #define SDVDD_POWER_ON		1
114 
115 #define SDEDM_FORCE_DATA_MODE	BIT(19)
116 #define SDEDM_CLOCK_PULSE	BIT(20)
117 #define SDEDM_BYPASS		BIT(21)
118 
119 #define SDEDM_FIFO_FILL_SHIFT	4
120 #define SDEDM_FIFO_FILL_MASK	0x1f
121 static u32 edm_fifo_fill(u32 edm)
122 {
123 	return (edm >> SDEDM_FIFO_FILL_SHIFT) & SDEDM_FIFO_FILL_MASK;
124 }
125 
126 #define SDEDM_WRITE_THRESHOLD_SHIFT	9
127 #define SDEDM_READ_THRESHOLD_SHIFT	14
128 #define SDEDM_THRESHOLD_MASK		0x1f
129 
130 #define SDEDM_FSM_MASK		0xf
131 #define SDEDM_FSM_IDENTMODE	0x0
132 #define SDEDM_FSM_DATAMODE	0x1
133 #define SDEDM_FSM_READDATA	0x2
134 #define SDEDM_FSM_WRITEDATA	0x3
135 #define SDEDM_FSM_READWAIT	0x4
136 #define SDEDM_FSM_READCRC	0x5
137 #define SDEDM_FSM_WRITECRC	0x6
138 #define SDEDM_FSM_WRITEWAIT1	0x7
139 #define SDEDM_FSM_POWERDOWN	0x8
140 #define SDEDM_FSM_POWERUP	0x9
141 #define SDEDM_FSM_WRITESTART1	0xa
142 #define SDEDM_FSM_WRITESTART2	0xb
143 #define SDEDM_FSM_GENPULSES	0xc
144 #define SDEDM_FSM_WRITEWAIT2	0xd
145 #define SDEDM_FSM_STARTPOWDOWN	0xf
146 
147 #define SDDATA_FIFO_WORDS	16
148 
149 #define FIFO_READ_THRESHOLD	4
150 #define FIFO_WRITE_THRESHOLD	4
151 #define SDDATA_FIFO_PIO_BURST	8
152 
153 #define SDHST_TIMEOUT_MAX_USEC	100000
154 
155 struct bcm2835_plat {
156 	struct mmc_config cfg;
157 	struct mmc mmc;
158 };
159 
160 struct bcm2835_host {
161 	void __iomem		*ioaddr;
162 	u32			phys_addr;
163 
164 	int			clock;		/* Current clock speed */
165 	unsigned int		max_clk;	/* Max possible freq */
166 	unsigned int		blocks;		/* remaining PIO blocks */
167 	int			irq;		/* Device IRQ */
168 
169 	u32			ns_per_fifo_word;
170 
171 	/* cached registers */
172 	u32			hcfg;
173 	u32			cdiv;
174 
175 	struct mmc_cmd	*cmd;		/* Current command */
176 	struct mmc_data		*data;		/* Current data request */
177 	bool			data_complete:1;/* Data finished before cmd */
178 	bool			use_busy:1;	/* Wait for busy interrupt */
179 	bool			wait_data_complete:1;	/* Wait for data */
180 
181 	/* for threaded irq handler */
182 	bool			irq_block;
183 	bool			irq_busy;
184 	bool			irq_data;
185 
186 	struct udevice		*dev;
187 	struct mmc		*mmc;
188 	struct bcm2835_plat	*plat;
189 };
190 
191 static void bcm2835_dumpregs(struct bcm2835_host *host)
192 {
193 	dev_dbg(dev, "=========== REGISTER DUMP ===========\n");
194 	dev_dbg(dev, "SDCMD  0x%08x\n", readl(host->ioaddr + SDCMD));
195 	dev_dbg(dev, "SDARG  0x%08x\n", readl(host->ioaddr + SDARG));
196 	dev_dbg(dev, "SDTOUT 0x%08x\n", readl(host->ioaddr + SDTOUT));
197 	dev_dbg(dev, "SDCDIV 0x%08x\n", readl(host->ioaddr + SDCDIV));
198 	dev_dbg(dev, "SDRSP0 0x%08x\n", readl(host->ioaddr + SDRSP0));
199 	dev_dbg(dev, "SDRSP1 0x%08x\n", readl(host->ioaddr + SDRSP1));
200 	dev_dbg(dev, "SDRSP2 0x%08x\n", readl(host->ioaddr + SDRSP2));
201 	dev_dbg(dev, "SDRSP3 0x%08x\n", readl(host->ioaddr + SDRSP3));
202 	dev_dbg(dev, "SDHSTS 0x%08x\n", readl(host->ioaddr + SDHSTS));
203 	dev_dbg(dev, "SDVDD  0x%08x\n", readl(host->ioaddr + SDVDD));
204 	dev_dbg(dev, "SDEDM  0x%08x\n", readl(host->ioaddr + SDEDM));
205 	dev_dbg(dev, "SDHCFG 0x%08x\n", readl(host->ioaddr + SDHCFG));
206 	dev_dbg(dev, "SDHBCT 0x%08x\n", readl(host->ioaddr + SDHBCT));
207 	dev_dbg(dev, "SDHBLC 0x%08x\n", readl(host->ioaddr + SDHBLC));
208 	dev_dbg(dev, "===========================================\n");
209 }
210 
211 static void bcm2835_reset_internal(struct bcm2835_host *host)
212 {
213 	u32 temp;
214 
215 	writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
216 	writel(0, host->ioaddr + SDCMD);
217 	writel(0, host->ioaddr + SDARG);
218 	/* Set timeout to a big enough value so we don't hit it */
219 	writel(0xf00000, host->ioaddr + SDTOUT);
220 	writel(0, host->ioaddr + SDCDIV);
221 	/* Clear status register */
222 	writel(SDHSTS_CLEAR_MASK, host->ioaddr + SDHSTS);
223 	writel(0, host->ioaddr + SDHCFG);
224 	writel(0, host->ioaddr + SDHBCT);
225 	writel(0, host->ioaddr + SDHBLC);
226 
227 	/* Limit fifo usage due to silicon bug */
228 	temp = readl(host->ioaddr + SDEDM);
229 	temp &= ~((SDEDM_THRESHOLD_MASK << SDEDM_READ_THRESHOLD_SHIFT) |
230 		  (SDEDM_THRESHOLD_MASK << SDEDM_WRITE_THRESHOLD_SHIFT));
231 	temp |= (FIFO_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) |
232 		(FIFO_WRITE_THRESHOLD << SDEDM_WRITE_THRESHOLD_SHIFT);
233 	writel(temp, host->ioaddr + SDEDM);
234 	/* Wait for FIFO threshold to populate */
235 	msleep(20);
236 	writel(SDVDD_POWER_ON, host->ioaddr + SDVDD);
237 	/* Wait for all components to go through power on cycle */
238 	msleep(20);
239 	host->clock = 0;
240 	writel(host->hcfg, host->ioaddr + SDHCFG);
241 	writel(host->cdiv, host->ioaddr + SDCDIV);
242 }
243 
244 static int bcm2835_finish_command(struct bcm2835_host *host);
245 
246 static void bcm2835_wait_transfer_complete(struct bcm2835_host *host)
247 {
248 	int timediff;
249 	u32 alternate_idle;
250 
251 	alternate_idle = (host->data->flags & MMC_DATA_READ) ?
252 		SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1;
253 
254 	timediff = 0;
255 
256 	while (1) {
257 		u32 edm, fsm;
258 
259 		edm = readl(host->ioaddr + SDEDM);
260 		fsm = edm & SDEDM_FSM_MASK;
261 
262 		if ((fsm == SDEDM_FSM_IDENTMODE) ||
263 		    (fsm == SDEDM_FSM_DATAMODE))
264 			break;
265 		if (fsm == alternate_idle) {
266 			writel(edm | SDEDM_FORCE_DATA_MODE,
267 			       host->ioaddr + SDEDM);
268 			break;
269 		}
270 
271 		/* Error out after 100000 register reads (~1s) */
272 		if (timediff++ == 100000) {
273 			dev_err(host->dev,
274 				"wait_transfer_complete - still waiting after %d retries\n",
275 				timediff);
276 			bcm2835_dumpregs(host);
277 			return;
278 		}
279 	}
280 }
281 
282 static int bcm2835_transfer_block_pio(struct bcm2835_host *host, bool is_read)
283 {
284 	struct mmc_data *data = host->data;
285 	size_t blksize = data->blocksize;
286 	int copy_words;
287 	u32 hsts = 0;
288 	u32 *buf;
289 
290 	if (blksize % sizeof(u32))
291 		return -EINVAL;
292 
293 	buf = is_read ? (u32 *)data->dest : (u32 *)data->src;
294 
295 	if (is_read)
296 		data->dest += blksize;
297 	else
298 		data->src += blksize;
299 
300 	copy_words = blksize / sizeof(u32);
301 
302 	/*
303 	 * Copy all contents from/to the FIFO as far as it reaches,
304 	 * then wait for it to fill/empty again and rewind.
305 	 */
306 	while (copy_words) {
307 		int burst_words, words;
308 		u32 edm;
309 
310 		burst_words = min(SDDATA_FIFO_PIO_BURST, copy_words);
311 		edm = readl(host->ioaddr + SDEDM);
312 		if (is_read)
313 			words = edm_fifo_fill(edm);
314 		else
315 			words = SDDATA_FIFO_WORDS - edm_fifo_fill(edm);
316 
317 		if (words < burst_words) {
318 			int fsm_state = (edm & SDEDM_FSM_MASK);
319 
320 			if ((is_read &&
321 			     (fsm_state != SDEDM_FSM_READDATA &&
322 			      fsm_state != SDEDM_FSM_READWAIT &&
323 			      fsm_state != SDEDM_FSM_READCRC)) ||
324 			    (!is_read &&
325 			     (fsm_state != SDEDM_FSM_WRITEDATA &&
326 			      fsm_state != SDEDM_FSM_WRITESTART1 &&
327 			      fsm_state != SDEDM_FSM_WRITESTART2))) {
328 				hsts = readl(host->ioaddr + SDHSTS);
329 				printf("fsm %x, hsts %08x\n", fsm_state, hsts);
330 				if (hsts & SDHSTS_ERROR_MASK)
331 					break;
332 			}
333 
334 			continue;
335 		} else if (words > copy_words) {
336 			words = copy_words;
337 		}
338 
339 		copy_words -= words;
340 
341 		/* Copy current chunk to/from the FIFO */
342 		while (words) {
343 			if (is_read)
344 				*(buf++) = readl(host->ioaddr + SDDATA);
345 			else
346 				writel(*(buf++), host->ioaddr + SDDATA);
347 			words--;
348 		}
349 	}
350 
351 	return 0;
352 }
353 
354 static int bcm2835_transfer_pio(struct bcm2835_host *host)
355 {
356 	u32 sdhsts;
357 	bool is_read;
358 	int ret = 0;
359 
360 	is_read = (host->data->flags & MMC_DATA_READ) != 0;
361 	ret = bcm2835_transfer_block_pio(host, is_read);
362 
363 	if (host->wait_data_complete)
364 		bcm2835_wait_transfer_complete(host);
365 
366 	sdhsts = readl(host->ioaddr + SDHSTS);
367 	if (sdhsts & (SDHSTS_CRC16_ERROR |
368 		      SDHSTS_CRC7_ERROR |
369 		      SDHSTS_FIFO_ERROR)) {
370 		printf("%s transfer error - HSTS %08x\n",
371 		       is_read ? "read" : "write", sdhsts);
372 		ret =  -EILSEQ;
373 	} else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
374 			      SDHSTS_REW_TIME_OUT))) {
375 		printf("%s timeout error - HSTS %08x\n",
376 		       is_read ? "read" : "write", sdhsts);
377 		ret = -ETIMEDOUT;
378 	}
379 
380 	return ret;
381 }
382 
383 static void bcm2835_set_transfer_irqs(struct bcm2835_host *host)
384 {
385 	u32 all_irqs = SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN |
386 		SDHCFG_BUSY_IRPT_EN;
387 
388 	host->hcfg = (host->hcfg & ~all_irqs) |
389 		SDHCFG_DATA_IRPT_EN |
390 		SDHCFG_BUSY_IRPT_EN;
391 
392 	writel(host->hcfg, host->ioaddr + SDHCFG);
393 }
394 
395 static
396 void bcm2835_prepare_data(struct bcm2835_host *host, struct mmc_cmd *cmd,
397 			  struct mmc_data *data)
398 {
399 	WARN_ON(host->data);
400 
401 	host->data = data;
402 	if (!data)
403 		return;
404 
405 	host->wait_data_complete = cmd->cmdidx != MMC_CMD_READ_MULTIPLE_BLOCK;
406 	host->data_complete = false;
407 
408 	/* Use PIO */
409 	host->blocks = data->blocks;
410 
411 	bcm2835_set_transfer_irqs(host);
412 
413 	writel(data->blocksize, host->ioaddr + SDHBCT);
414 	writel(data->blocks, host->ioaddr + SDHBLC);
415 }
416 
417 static u32 bcm2835_read_wait_sdcmd(struct bcm2835_host *host)
418 {
419 	u32 value;
420 	int ret;
421 	int timeout_us = SDHST_TIMEOUT_MAX_USEC;
422 
423 	ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
424 				 !(value & SDCMD_NEW_FLAG), timeout_us);
425 	if (ret == -ETIMEDOUT)
426 		printf("%s: timeout (%d us)\n", __func__, timeout_us);
427 
428 	return value;
429 }
430 
431 static int bcm2835_send_command(struct bcm2835_host *host, struct mmc_cmd *cmd,
432 				struct mmc_data *data)
433 {
434 	u32 sdcmd, sdhsts;
435 
436 	WARN_ON(host->cmd);
437 
438 	if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY)) {
439 		printf("unsupported response type!\n");
440 		return -EINVAL;
441 	}
442 
443 	sdcmd = bcm2835_read_wait_sdcmd(host);
444 	if (sdcmd & SDCMD_NEW_FLAG) {
445 		printf("previous command never completed.\n");
446 		bcm2835_dumpregs(host);
447 		return -EBUSY;
448 	}
449 
450 	host->cmd = cmd;
451 
452 	/* Clear any error flags */
453 	sdhsts = readl(host->ioaddr + SDHSTS);
454 	if (sdhsts & SDHSTS_ERROR_MASK)
455 		writel(sdhsts, host->ioaddr + SDHSTS);
456 
457 	bcm2835_prepare_data(host, cmd, data);
458 
459 	writel(cmd->cmdarg, host->ioaddr + SDARG);
460 
461 	sdcmd = cmd->cmdidx & SDCMD_CMD_MASK;
462 
463 	host->use_busy = false;
464 	if (!(cmd->resp_type & MMC_RSP_PRESENT)) {
465 		sdcmd |= SDCMD_NO_RESPONSE;
466 	} else {
467 		if (cmd->resp_type & MMC_RSP_136)
468 			sdcmd |= SDCMD_LONG_RESPONSE;
469 		if (cmd->resp_type & MMC_RSP_BUSY) {
470 			sdcmd |= SDCMD_BUSYWAIT;
471 			host->use_busy = true;
472 		}
473 	}
474 
475 	if (data) {
476 		if (data->flags & MMC_DATA_WRITE)
477 			sdcmd |= SDCMD_WRITE_CMD;
478 		if (data->flags & MMC_DATA_READ)
479 			sdcmd |= SDCMD_READ_CMD;
480 	}
481 
482 	writel(sdcmd | SDCMD_NEW_FLAG, host->ioaddr + SDCMD);
483 
484 	return 0;
485 }
486 
487 static int bcm2835_transfer_complete(struct bcm2835_host *host)
488 {
489 	int ret = 0;
490 
491 	WARN_ON(!host->data_complete);
492 
493 	host->data = NULL;
494 
495 	return ret;
496 }
497 
498 static void bcm2835_finish_data(struct bcm2835_host *host)
499 {
500 	host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
501 	writel(host->hcfg, host->ioaddr + SDHCFG);
502 
503 	host->data_complete = true;
504 
505 	if (host->cmd) {
506 		/* Data managed to finish before the
507 		 * command completed. Make sure we do
508 		 * things in the proper order.
509 		 */
510 		dev_dbg(dev, "Finished early - HSTS %08x\n",
511 			readl(host->ioaddr + SDHSTS));
512 	} else {
513 		bcm2835_transfer_complete(host);
514 	}
515 }
516 
517 static int bcm2835_finish_command(struct bcm2835_host *host)
518 {
519 	struct mmc_cmd *cmd = host->cmd;
520 	u32 sdcmd;
521 	int ret = 0;
522 
523 	sdcmd = bcm2835_read_wait_sdcmd(host);
524 
525 	/* Check for errors */
526 	if (sdcmd & SDCMD_NEW_FLAG) {
527 		printf("command never completed.\n");
528 		bcm2835_dumpregs(host);
529 		return -EIO;
530 	} else if (sdcmd & SDCMD_FAIL_FLAG) {
531 		u32 sdhsts = readl(host->ioaddr + SDHSTS);
532 
533 		/* Clear the errors */
534 		writel(SDHSTS_ERROR_MASK, host->ioaddr + SDHSTS);
535 
536 		if (!(sdhsts & SDHSTS_CRC7_ERROR) ||
537 		    (host->cmd->cmdidx != MMC_CMD_SEND_OP_COND)) {
538 			if (sdhsts & SDHSTS_CMD_TIME_OUT) {
539 				ret = -ETIMEDOUT;
540 			} else {
541 				printf("unexpected command %d error\n",
542 				       host->cmd->cmdidx);
543 				bcm2835_dumpregs(host);
544 				ret = -EILSEQ;
545 			}
546 
547 			return ret;
548 		}
549 	}
550 
551 	if (cmd->resp_type & MMC_RSP_PRESENT) {
552 		if (cmd->resp_type & MMC_RSP_136) {
553 			int i;
554 
555 			for (i = 0; i < 4; i++) {
556 				cmd->response[3 - i] =
557 					readl(host->ioaddr + SDRSP0 + i * 4);
558 			}
559 		} else {
560 			cmd->response[0] = readl(host->ioaddr + SDRSP0);
561 		}
562 	}
563 
564 	/* Processed actual command. */
565 	host->cmd = NULL;
566 	if (host->data && host->data_complete)
567 		ret = bcm2835_transfer_complete(host);
568 
569 	return ret;
570 }
571 
572 static int bcm2835_check_cmd_error(struct bcm2835_host *host, u32 intmask)
573 {
574 	int ret = -EINVAL;
575 
576 	if (!(intmask & SDHSTS_ERROR_MASK))
577 		return 0;
578 
579 	if (!host->cmd)
580 		return -EINVAL;
581 
582 	printf("sdhost_busy_irq: intmask %08x\n", intmask);
583 	if (intmask & SDHSTS_CRC7_ERROR) {
584 		ret = -EILSEQ;
585 	} else if (intmask & (SDHSTS_CRC16_ERROR |
586 			      SDHSTS_FIFO_ERROR)) {
587 		ret = -EILSEQ;
588 	} else if (intmask & (SDHSTS_REW_TIME_OUT | SDHSTS_CMD_TIME_OUT)) {
589 		ret = -ETIMEDOUT;
590 	}
591 	bcm2835_dumpregs(host);
592 	return ret;
593 }
594 
595 static int bcm2835_check_data_error(struct bcm2835_host *host, u32 intmask)
596 {
597 	int ret = 0;
598 
599 	if (!host->data)
600 		return 0;
601 	if (intmask & (SDHSTS_CRC16_ERROR | SDHSTS_FIFO_ERROR))
602 		ret = -EILSEQ;
603 	if (intmask & SDHSTS_REW_TIME_OUT)
604 		ret = -ETIMEDOUT;
605 
606 	if (ret)
607 		printf("%s:%d %d\n", __func__, __LINE__, ret);
608 
609 	return ret;
610 }
611 
612 static void bcm2835_busy_irq(struct bcm2835_host *host)
613 {
614 	if (WARN_ON(!host->cmd)) {
615 		bcm2835_dumpregs(host);
616 		return;
617 	}
618 
619 	if (WARN_ON(!host->use_busy)) {
620 		bcm2835_dumpregs(host);
621 		return;
622 	}
623 	host->use_busy = false;
624 
625 	bcm2835_finish_command(host);
626 }
627 
628 static void bcm2835_data_irq(struct bcm2835_host *host, u32 intmask)
629 {
630 	int ret;
631 
632 	/*
633 	 * There are no dedicated data/space available interrupt
634 	 * status bits, so it is necessary to use the single shared
635 	 * data/space available FIFO status bits. It is therefore not
636 	 * an error to get here when there is no data transfer in
637 	 * progress.
638 	 */
639 	if (!host->data)
640 		return;
641 
642 	ret = bcm2835_check_data_error(host, intmask);
643 	if (ret)
644 		goto finished;
645 
646 	if (host->data->flags & MMC_DATA_WRITE) {
647 		/* Use the block interrupt for writes after the first block */
648 		host->hcfg &= ~(SDHCFG_DATA_IRPT_EN);
649 		host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
650 		writel(host->hcfg, host->ioaddr + SDHCFG);
651 		bcm2835_transfer_pio(host);
652 	} else {
653 		bcm2835_transfer_pio(host);
654 		host->blocks--;
655 		if ((host->blocks == 0))
656 			goto finished;
657 	}
658 	return;
659 
660 finished:
661 	host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
662 	writel(host->hcfg, host->ioaddr + SDHCFG);
663 }
664 
665 static void bcm2835_data_threaded_irq(struct bcm2835_host *host)
666 {
667 	if (!host->data)
668 		return;
669 	if ((host->blocks == 0))
670 		bcm2835_finish_data(host);
671 }
672 
673 static void bcm2835_block_irq(struct bcm2835_host *host)
674 {
675 	if (WARN_ON(!host->data)) {
676 		bcm2835_dumpregs(host);
677 		return;
678 	}
679 
680 	WARN_ON(!host->blocks);
681 	if ((--host->blocks == 0))
682 		bcm2835_finish_data(host);
683 	else
684 		bcm2835_transfer_pio(host);
685 }
686 
687 static irqreturn_t bcm2835_irq(int irq, void *dev_id)
688 {
689 	irqreturn_t result = IRQ_NONE;
690 	struct bcm2835_host *host = dev_id;
691 	u32 intmask;
692 
693 	intmask = readl(host->ioaddr + SDHSTS);
694 
695 	writel(SDHSTS_BUSY_IRPT |
696 	       SDHSTS_BLOCK_IRPT |
697 	       SDHSTS_SDIO_IRPT |
698 	       SDHSTS_DATA_FLAG,
699 	       host->ioaddr + SDHSTS);
700 
701 	if (intmask & SDHSTS_BLOCK_IRPT) {
702 		bcm2835_check_data_error(host, intmask);
703 		host->irq_block = true;
704 		result = IRQ_WAKE_THREAD;
705 	}
706 
707 	if (intmask & SDHSTS_BUSY_IRPT) {
708 		if (!bcm2835_check_cmd_error(host, intmask)) {
709 			host->irq_busy = true;
710 			result = IRQ_WAKE_THREAD;
711 		} else {
712 			result = IRQ_HANDLED;
713 		}
714 	}
715 
716 	/* There is no true data interrupt status bit, so it is
717 	 * necessary to qualify the data flag with the interrupt
718 	 * enable bit.
719 	 */
720 	if ((intmask & SDHSTS_DATA_FLAG) &&
721 	    (host->hcfg & SDHCFG_DATA_IRPT_EN)) {
722 		bcm2835_data_irq(host, intmask);
723 		host->irq_data = true;
724 		result = IRQ_WAKE_THREAD;
725 	}
726 
727 	return result;
728 }
729 
730 static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id)
731 {
732 	struct bcm2835_host *host = dev_id;
733 
734 	if (host->irq_block) {
735 		host->irq_block = false;
736 		bcm2835_block_irq(host);
737 	}
738 
739 	if (host->irq_busy) {
740 		host->irq_busy = false;
741 		bcm2835_busy_irq(host);
742 	}
743 
744 	if (host->irq_data) {
745 		host->irq_data = false;
746 		bcm2835_data_threaded_irq(host);
747 	}
748 
749 	return IRQ_HANDLED;
750 }
751 
752 static void bcm2835_irq_poll(struct bcm2835_host *host)
753 {
754 	u32 intmask;
755 
756 	while (1) {
757 		intmask = readl(host->ioaddr + SDHSTS);
758 		if (intmask & (SDHSTS_BUSY_IRPT | SDHSTS_BLOCK_IRPT |
759 			       SDHSTS_SDIO_IRPT | SDHSTS_DATA_FLAG)) {
760 			bcm2835_irq(0, host);
761 			bcm2835_threaded_irq(0, host);
762 			return;
763 		}
764 	}
765 }
766 
767 static void bcm2835_set_clock(struct bcm2835_host *host, unsigned int clock)
768 {
769 	int div;
770 
771 	/* The SDCDIV register has 11 bits, and holds (div - 2).  But
772 	 * in data mode the max is 50MHz wihout a minimum, and only
773 	 * the bottom 3 bits are used. Since the switch over is
774 	 * automatic (unless we have marked the card as slow...),
775 	 * chosen values have to make sense in both modes.  Ident mode
776 	 * must be 100-400KHz, so can range check the requested
777 	 * clock. CMD15 must be used to return to data mode, so this
778 	 * can be monitored.
779 	 *
780 	 * clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz
781 	 *                 4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz
782 	 *
783 	 *		 623->400KHz/27.8MHz
784 	 *		 reset value (507)->491159/50MHz
785 	 *
786 	 * BUT, the 3-bit clock divisor in data mode is too small if
787 	 * the core clock is higher than 250MHz, so instead use the
788 	 * SLOW_CARD configuration bit to force the use of the ident
789 	 * clock divisor at all times.
790 	 */
791 
792 	if (clock < 100000) {
793 		/* Can't stop the clock, but make it as slow as possible
794 		 * to show willing
795 		 */
796 		host->cdiv = SDCDIV_MAX_CDIV;
797 		writel(host->cdiv, host->ioaddr + SDCDIV);
798 		return;
799 	}
800 
801 	div = host->max_clk / clock;
802 	if (div < 2)
803 		div = 2;
804 	if ((host->max_clk / div) > clock)
805 		div++;
806 	div -= 2;
807 
808 	if (div > SDCDIV_MAX_CDIV)
809 		div = SDCDIV_MAX_CDIV;
810 
811 	clock = host->max_clk / (div + 2);
812 	host->mmc->clock = clock;
813 
814 	/* Calibrate some delays */
815 
816 	host->ns_per_fifo_word = (1000000000 / clock) *
817 		((host->mmc->card_caps & MMC_MODE_4BIT) ? 8 : 32);
818 
819 	host->cdiv = div;
820 	writel(host->cdiv, host->ioaddr + SDCDIV);
821 
822 	/* Set the timeout to 500ms */
823 	writel(host->mmc->clock / 2, host->ioaddr + SDTOUT);
824 }
825 
826 static inline int is_power_of_2(u64 x)
827 {
828 	return !(x & (x - 1));
829 }
830 
831 static int bcm2835_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
832 			    struct mmc_data *data)
833 {
834 	struct bcm2835_host *host = dev_get_priv(dev);
835 	u32 edm, fsm;
836 	int ret = 0;
837 
838 	if (data && !is_power_of_2(data->blocksize)) {
839 		printf("unsupported block size (%d bytes)\n", data->blocksize);
840 
841 		if (cmd)
842 			return -EINVAL;
843 	}
844 
845 	edm = readl(host->ioaddr + SDEDM);
846 	fsm = edm & SDEDM_FSM_MASK;
847 
848 	if ((fsm != SDEDM_FSM_IDENTMODE) &&
849 	    (fsm != SDEDM_FSM_DATAMODE) &&
850 	    (cmd && cmd->cmdidx != MMC_CMD_STOP_TRANSMISSION)) {
851 		printf("previous command (%d) not complete (EDM %08x)\n",
852 		       readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK, edm);
853 		bcm2835_dumpregs(host);
854 
855 		if (cmd)
856 			return -EILSEQ;
857 
858 		return 0;
859 	}
860 
861 	if (cmd) {
862 		ret = bcm2835_send_command(host, cmd, data);
863 		if (!ret && !host->use_busy)
864 			ret = bcm2835_finish_command(host);
865 	}
866 
867 	/* Wait for completion of busy signal or data transfer */
868 	while (host->use_busy || host->data)
869 		bcm2835_irq_poll(host);
870 
871 	return ret;
872 }
873 
874 static int bcm2835_set_ios(struct udevice *dev)
875 {
876 	struct bcm2835_host *host = dev_get_priv(dev);
877 	struct mmc *mmc = mmc_get_mmc_dev(dev);
878 
879 	if (!mmc->clock || mmc->clock != host->clock) {
880 		bcm2835_set_clock(host, mmc->clock);
881 		host->clock = mmc->clock;
882 	}
883 
884 	/* set bus width */
885 	host->hcfg &= ~SDHCFG_WIDE_EXT_BUS;
886 	if (mmc->bus_width == 4)
887 		host->hcfg |= SDHCFG_WIDE_EXT_BUS;
888 
889 	host->hcfg |= SDHCFG_WIDE_INT_BUS;
890 
891 	/* Disable clever clock switching, to cope with fast core clocks */
892 	host->hcfg |= SDHCFG_SLOW_CARD;
893 
894 	writel(host->hcfg, host->ioaddr + SDHCFG);
895 
896 	return 0;
897 }
898 
899 static void bcm2835_add_host(struct bcm2835_host *host)
900 {
901 	struct mmc_config *cfg = &host->plat->cfg;
902 
903 	cfg->f_max = host->max_clk;
904 	cfg->f_min = host->max_clk / SDCDIV_MAX_CDIV;
905 	cfg->b_max = 65535;
906 
907 	dev_dbg(dev, "f_max %d, f_min %d\n",
908 		cfg->f_max, cfg->f_min);
909 
910 	/* host controller capabilities */
911 	cfg->host_caps = MMC_MODE_4BIT | MMC_MODE_HS | MMC_MODE_HS_52MHz;
912 
913 	/* report supported voltage ranges */
914 	cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
915 
916 	/* Set interrupt enables */
917 	host->hcfg = SDHCFG_BUSY_IRPT_EN;
918 
919 	bcm2835_reset_internal(host);
920 }
921 
922 static int bcm2835_probe(struct udevice *dev)
923 {
924 	struct bcm2835_plat *plat = dev_get_platdata(dev);
925 	struct bcm2835_host *host = dev_get_priv(dev);
926 	struct mmc *mmc = mmc_get_mmc_dev(dev);
927 	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
928 
929 	host->dev = dev;
930 	host->mmc = mmc;
931 	host->plat = plat;
932 	upriv->mmc = &plat->mmc;
933 	plat->cfg.name = dev->name;
934 
935 	host->phys_addr = devfdt_get_addr(dev);
936 	if (host->phys_addr == FDT_ADDR_T_NONE)
937 		return -EINVAL;
938 
939 	host->ioaddr = devm_ioremap(dev, host->phys_addr, SZ_256);
940 	if (!host->ioaddr)
941 		return -ENOMEM;
942 
943 	host->max_clk = bcm2835_get_mmc_clock(BCM2835_MBOX_CLOCK_ID_CORE);
944 
945 	bcm2835_add_host(host);
946 
947 	dev_dbg(dev, "%s -> OK\n", __func__);
948 
949 	return 0;
950 }
951 
952 static const struct udevice_id bcm2835_match[] = {
953 	{ .compatible = "brcm,bcm2835-sdhost" },
954 	{ }
955 };
956 
957 static const struct dm_mmc_ops bcm2835_ops = {
958 	.send_cmd = bcm2835_send_cmd,
959 	.set_ios = bcm2835_set_ios,
960 };
961 
962 static int bcm2835_bind(struct udevice *dev)
963 {
964 	struct bcm2835_plat *plat = dev_get_platdata(dev);
965 
966 	return mmc_bind(dev, &plat->mmc, &plat->cfg);
967 }
968 
969 U_BOOT_DRIVER(bcm2835_sdhost) = {
970 	.name = "bcm2835-sdhost",
971 	.id = UCLASS_MMC,
972 	.of_match = bcm2835_match,
973 	.bind = bcm2835_bind,
974 	.probe = bcm2835_probe,
975 	.priv_auto_alloc_size = sizeof(struct bcm2835_host),
976 	.platdata_auto_alloc_size = sizeof(struct bcm2835_plat),
977 	.ops = &bcm2835_ops,
978 };
979