xref: /rk3399_rockchip-uboot/drivers/mmc/tegra_mmc.c (revision c9aa831ee26f629fbd2df67cab8bb357777e2256)
1 /*
2  * (C) Copyright 2009 SAMSUNG Electronics
3  * Minkyu Kang <mk7.kang@samsung.com>
4  * Jaehoon Chung <jh80.chung@samsung.com>
5  * Portions Copyright 2011-2013 NVIDIA Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20  */
21 
22 #include <bouncebuf.h>
23 #include <common.h>
24 #include <fdtdec.h>
25 #include <asm/gpio.h>
26 #include <asm/io.h>
27 #include <asm/arch/clock.h>
28 #include <asm/arch-tegra/clk_rst.h>
29 #include <asm/arch-tegra/tegra_mmc.h>
30 #include <mmc.h>
31 
32 DECLARE_GLOBAL_DATA_PTR;
33 
34 struct mmc mmc_dev[MAX_HOSTS];
35 struct mmc_host mmc_host[MAX_HOSTS];
36 
37 #ifndef CONFIG_OF_CONTROL
38 #error "Please enable device tree support to use this driver"
39 #endif
40 
41 static void mmc_prepare_data(struct mmc_host *host, struct mmc_data *data,
42 				struct bounce_buffer *bbstate)
43 {
44 	unsigned char ctrl;
45 
46 
47 	debug("buf: %p (%p), data->blocks: %u, data->blocksize: %u\n",
48 		bbstate->bounce_buffer, bbstate->user_buffer, data->blocks,
49 		data->blocksize);
50 
51 	writel((u32)bbstate->bounce_buffer, &host->reg->sysad);
52 	/*
53 	 * DMASEL[4:3]
54 	 * 00 = Selects SDMA
55 	 * 01 = Reserved
56 	 * 10 = Selects 32-bit Address ADMA2
57 	 * 11 = Selects 64-bit Address ADMA2
58 	 */
59 	ctrl = readb(&host->reg->hostctl);
60 	ctrl &= ~TEGRA_MMC_HOSTCTL_DMASEL_MASK;
61 	ctrl |= TEGRA_MMC_HOSTCTL_DMASEL_SDMA;
62 	writeb(ctrl, &host->reg->hostctl);
63 
64 	/* We do not handle DMA boundaries, so set it to max (512 KiB) */
65 	writew((7 << 12) | (data->blocksize & 0xFFF), &host->reg->blksize);
66 	writew(data->blocks, &host->reg->blkcnt);
67 }
68 
69 static void mmc_set_transfer_mode(struct mmc_host *host, struct mmc_data *data)
70 {
71 	unsigned short mode;
72 	debug(" mmc_set_transfer_mode called\n");
73 	/*
74 	 * TRNMOD
75 	 * MUL1SIN0[5]	: Multi/Single Block Select
76 	 * RD1WT0[4]	: Data Transfer Direction Select
77 	 *	1 = read
78 	 *	0 = write
79 	 * ENACMD12[2]	: Auto CMD12 Enable
80 	 * ENBLKCNT[1]	: Block Count Enable
81 	 * ENDMA[0]	: DMA Enable
82 	 */
83 	mode = (TEGRA_MMC_TRNMOD_DMA_ENABLE |
84 		TEGRA_MMC_TRNMOD_BLOCK_COUNT_ENABLE);
85 
86 	if (data->blocks > 1)
87 		mode |= TEGRA_MMC_TRNMOD_MULTI_BLOCK_SELECT;
88 
89 	if (data->flags & MMC_DATA_READ)
90 		mode |= TEGRA_MMC_TRNMOD_DATA_XFER_DIR_SEL_READ;
91 
92 	writew(mode, &host->reg->trnmod);
93 }
94 
95 static int mmc_wait_inhibit(struct mmc_host *host,
96 			    struct mmc_cmd *cmd,
97 			    struct mmc_data *data,
98 			    unsigned int timeout)
99 {
100 	/*
101 	 * PRNSTS
102 	 * CMDINHDAT[1] : Command Inhibit (DAT)
103 	 * CMDINHCMD[0] : Command Inhibit (CMD)
104 	 */
105 	unsigned int mask = TEGRA_MMC_PRNSTS_CMD_INHIBIT_CMD;
106 
107 	/*
108 	 * We shouldn't wait for data inhibit for stop commands, even
109 	 * though they might use busy signaling
110 	 */
111 	if ((data == NULL) && (cmd->resp_type & MMC_RSP_BUSY))
112 		mask |= TEGRA_MMC_PRNSTS_CMD_INHIBIT_DAT;
113 
114 	while (readl(&host->reg->prnsts) & mask) {
115 		if (timeout == 0) {
116 			printf("%s: timeout error\n", __func__);
117 			return -1;
118 		}
119 		timeout--;
120 		udelay(1000);
121 	}
122 
123 	return 0;
124 }
125 
126 static int mmc_send_cmd_bounced(struct mmc *mmc, struct mmc_cmd *cmd,
127 			struct mmc_data *data, struct bounce_buffer *bbstate)
128 {
129 	struct mmc_host *host = (struct mmc_host *)mmc->priv;
130 	int flags, i;
131 	int result;
132 	unsigned int mask = 0;
133 	unsigned int retry = 0x100000;
134 	debug(" mmc_send_cmd called\n");
135 
136 	result = mmc_wait_inhibit(host, cmd, data, 10 /* ms */);
137 
138 	if (result < 0)
139 		return result;
140 
141 	if (data)
142 		mmc_prepare_data(host, data, bbstate);
143 
144 	debug("cmd->arg: %08x\n", cmd->cmdarg);
145 	writel(cmd->cmdarg, &host->reg->argument);
146 
147 	if (data)
148 		mmc_set_transfer_mode(host, data);
149 
150 	if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY))
151 		return -1;
152 
153 	/*
154 	 * CMDREG
155 	 * CMDIDX[13:8]	: Command index
156 	 * DATAPRNT[5]	: Data Present Select
157 	 * ENCMDIDX[4]	: Command Index Check Enable
158 	 * ENCMDCRC[3]	: Command CRC Check Enable
159 	 * RSPTYP[1:0]
160 	 *	00 = No Response
161 	 *	01 = Length 136
162 	 *	10 = Length 48
163 	 *	11 = Length 48 Check busy after response
164 	 */
165 	if (!(cmd->resp_type & MMC_RSP_PRESENT))
166 		flags = TEGRA_MMC_CMDREG_RESP_TYPE_SELECT_NO_RESPONSE;
167 	else if (cmd->resp_type & MMC_RSP_136)
168 		flags = TEGRA_MMC_CMDREG_RESP_TYPE_SELECT_LENGTH_136;
169 	else if (cmd->resp_type & MMC_RSP_BUSY)
170 		flags = TEGRA_MMC_CMDREG_RESP_TYPE_SELECT_LENGTH_48_BUSY;
171 	else
172 		flags = TEGRA_MMC_CMDREG_RESP_TYPE_SELECT_LENGTH_48;
173 
174 	if (cmd->resp_type & MMC_RSP_CRC)
175 		flags |= TEGRA_MMC_TRNMOD_CMD_CRC_CHECK;
176 	if (cmd->resp_type & MMC_RSP_OPCODE)
177 		flags |= TEGRA_MMC_TRNMOD_CMD_INDEX_CHECK;
178 	if (data)
179 		flags |= TEGRA_MMC_TRNMOD_DATA_PRESENT_SELECT_DATA_TRANSFER;
180 
181 	debug("cmd: %d\n", cmd->cmdidx);
182 
183 	writew((cmd->cmdidx << 8) | flags, &host->reg->cmdreg);
184 
185 	for (i = 0; i < retry; i++) {
186 		mask = readl(&host->reg->norintsts);
187 		/* Command Complete */
188 		if (mask & TEGRA_MMC_NORINTSTS_CMD_COMPLETE) {
189 			if (!data)
190 				writel(mask, &host->reg->norintsts);
191 			break;
192 		}
193 	}
194 
195 	if (i == retry) {
196 		printf("%s: waiting for status update\n", __func__);
197 		writel(mask, &host->reg->norintsts);
198 		return TIMEOUT;
199 	}
200 
201 	if (mask & TEGRA_MMC_NORINTSTS_CMD_TIMEOUT) {
202 		/* Timeout Error */
203 		debug("timeout: %08x cmd %d\n", mask, cmd->cmdidx);
204 		writel(mask, &host->reg->norintsts);
205 		return TIMEOUT;
206 	} else if (mask & TEGRA_MMC_NORINTSTS_ERR_INTERRUPT) {
207 		/* Error Interrupt */
208 		debug("error: %08x cmd %d\n", mask, cmd->cmdidx);
209 		writel(mask, &host->reg->norintsts);
210 		return -1;
211 	}
212 
213 	if (cmd->resp_type & MMC_RSP_PRESENT) {
214 		if (cmd->resp_type & MMC_RSP_136) {
215 			/* CRC is stripped so we need to do some shifting. */
216 			for (i = 0; i < 4; i++) {
217 				unsigned int offset =
218 					(unsigned int)(&host->reg->rspreg3 - i);
219 				cmd->response[i] = readl(offset) << 8;
220 
221 				if (i != 3) {
222 					cmd->response[i] |=
223 						readb(offset - 1);
224 				}
225 				debug("cmd->resp[%d]: %08x\n",
226 						i, cmd->response[i]);
227 			}
228 		} else if (cmd->resp_type & MMC_RSP_BUSY) {
229 			for (i = 0; i < retry; i++) {
230 				/* PRNTDATA[23:20] : DAT[3:0] Line Signal */
231 				if (readl(&host->reg->prnsts)
232 					& (1 << 20))	/* DAT[0] */
233 					break;
234 			}
235 
236 			if (i == retry) {
237 				printf("%s: card is still busy\n", __func__);
238 				writel(mask, &host->reg->norintsts);
239 				return TIMEOUT;
240 			}
241 
242 			cmd->response[0] = readl(&host->reg->rspreg0);
243 			debug("cmd->resp[0]: %08x\n", cmd->response[0]);
244 		} else {
245 			cmd->response[0] = readl(&host->reg->rspreg0);
246 			debug("cmd->resp[0]: %08x\n", cmd->response[0]);
247 		}
248 	}
249 
250 	if (data) {
251 		unsigned long	start = get_timer(0);
252 
253 		while (1) {
254 			mask = readl(&host->reg->norintsts);
255 
256 			if (mask & TEGRA_MMC_NORINTSTS_ERR_INTERRUPT) {
257 				/* Error Interrupt */
258 				writel(mask, &host->reg->norintsts);
259 				printf("%s: error during transfer: 0x%08x\n",
260 						__func__, mask);
261 				return -1;
262 			} else if (mask & TEGRA_MMC_NORINTSTS_DMA_INTERRUPT) {
263 				/*
264 				 * DMA Interrupt, restart the transfer where
265 				 * it was interrupted.
266 				 */
267 				unsigned int address = readl(&host->reg->sysad);
268 
269 				debug("DMA end\n");
270 				writel(TEGRA_MMC_NORINTSTS_DMA_INTERRUPT,
271 				       &host->reg->norintsts);
272 				writel(address, &host->reg->sysad);
273 			} else if (mask & TEGRA_MMC_NORINTSTS_XFER_COMPLETE) {
274 				/* Transfer Complete */
275 				debug("r/w is done\n");
276 				break;
277 			} else if (get_timer(start) > 2000UL) {
278 				writel(mask, &host->reg->norintsts);
279 				printf("%s: MMC Timeout\n"
280 				       "    Interrupt status        0x%08x\n"
281 				       "    Interrupt status enable 0x%08x\n"
282 				       "    Interrupt signal enable 0x%08x\n"
283 				       "    Present status          0x%08x\n",
284 				       __func__, mask,
285 				       readl(&host->reg->norintstsen),
286 				       readl(&host->reg->norintsigen),
287 				       readl(&host->reg->prnsts));
288 				return -1;
289 			}
290 		}
291 		writel(mask, &host->reg->norintsts);
292 	}
293 
294 	udelay(1000);
295 	return 0;
296 }
297 
298 static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
299 			struct mmc_data *data)
300 {
301 	void *buf;
302 	unsigned int bbflags;
303 	size_t len;
304 	struct bounce_buffer bbstate;
305 	int ret;
306 
307 	if (data) {
308 		if (data->flags & MMC_DATA_READ) {
309 			buf = data->dest;
310 			bbflags = GEN_BB_WRITE;
311 		} else {
312 			buf = (void *)data->src;
313 			bbflags = GEN_BB_READ;
314 		}
315 		len = data->blocks * data->blocksize;
316 
317 		bounce_buffer_start(&bbstate, buf, len, bbflags);
318 	}
319 
320 	ret = mmc_send_cmd_bounced(mmc, cmd, data, &bbstate);
321 
322 	if (data)
323 		bounce_buffer_stop(&bbstate);
324 
325 	return ret;
326 }
327 
328 static void mmc_change_clock(struct mmc_host *host, uint clock)
329 {
330 	int div;
331 	unsigned short clk;
332 	unsigned long timeout;
333 
334 	debug(" mmc_change_clock called\n");
335 
336 	/*
337 	 * Change Tegra SDMMCx clock divisor here. Source is 216MHz,
338 	 * PLLP_OUT0
339 	 */
340 	if (clock == 0)
341 		goto out;
342 	clock_adjust_periph_pll_div(host->mmc_id, CLOCK_ID_PERIPH, clock,
343 				    &div);
344 	debug("div = %d\n", div);
345 
346 	writew(0, &host->reg->clkcon);
347 
348 	/*
349 	 * CLKCON
350 	 * SELFREQ[15:8]	: base clock divided by value
351 	 * ENSDCLK[2]		: SD Clock Enable
352 	 * STBLINTCLK[1]	: Internal Clock Stable
353 	 * ENINTCLK[0]		: Internal Clock Enable
354 	 */
355 	div >>= 1;
356 	clk = ((div << TEGRA_MMC_CLKCON_SDCLK_FREQ_SEL_SHIFT) |
357 	       TEGRA_MMC_CLKCON_INTERNAL_CLOCK_ENABLE);
358 	writew(clk, &host->reg->clkcon);
359 
360 	/* Wait max 10 ms */
361 	timeout = 10;
362 	while (!(readw(&host->reg->clkcon) &
363 		 TEGRA_MMC_CLKCON_INTERNAL_CLOCK_STABLE)) {
364 		if (timeout == 0) {
365 			printf("%s: timeout error\n", __func__);
366 			return;
367 		}
368 		timeout--;
369 		udelay(1000);
370 	}
371 
372 	clk |= TEGRA_MMC_CLKCON_SD_CLOCK_ENABLE;
373 	writew(clk, &host->reg->clkcon);
374 
375 	debug("mmc_change_clock: clkcon = %08X\n", clk);
376 
377 out:
378 	host->clock = clock;
379 }
380 
381 static void mmc_set_ios(struct mmc *mmc)
382 {
383 	struct mmc_host *host = mmc->priv;
384 	unsigned char ctrl;
385 	debug(" mmc_set_ios called\n");
386 
387 	debug("bus_width: %x, clock: %d\n", mmc->bus_width, mmc->clock);
388 
389 	/* Change clock first */
390 	mmc_change_clock(host, mmc->clock);
391 
392 	ctrl = readb(&host->reg->hostctl);
393 
394 	/*
395 	 * WIDE8[5]
396 	 * 0 = Depend on WIDE4
397 	 * 1 = 8-bit mode
398 	 * WIDE4[1]
399 	 * 1 = 4-bit mode
400 	 * 0 = 1-bit mode
401 	 */
402 	if (mmc->bus_width == 8)
403 		ctrl |= (1 << 5);
404 	else if (mmc->bus_width == 4)
405 		ctrl |= (1 << 1);
406 	else
407 		ctrl &= ~(1 << 1);
408 
409 	writeb(ctrl, &host->reg->hostctl);
410 	debug("mmc_set_ios: hostctl = %08X\n", ctrl);
411 }
412 
413 static void mmc_reset(struct mmc_host *host)
414 {
415 	unsigned int timeout;
416 	debug(" mmc_reset called\n");
417 
418 	/*
419 	 * RSTALL[0] : Software reset for all
420 	 * 1 = reset
421 	 * 0 = work
422 	 */
423 	writeb(TEGRA_MMC_SWRST_SW_RESET_FOR_ALL, &host->reg->swrst);
424 
425 	host->clock = 0;
426 
427 	/* Wait max 100 ms */
428 	timeout = 100;
429 
430 	/* hw clears the bit when it's done */
431 	while (readb(&host->reg->swrst) & TEGRA_MMC_SWRST_SW_RESET_FOR_ALL) {
432 		if (timeout == 0) {
433 			printf("%s: timeout error\n", __func__);
434 			return;
435 		}
436 		timeout--;
437 		udelay(1000);
438 	}
439 }
440 
441 static int mmc_core_init(struct mmc *mmc)
442 {
443 	struct mmc_host *host = (struct mmc_host *)mmc->priv;
444 	unsigned int mask;
445 	debug(" mmc_core_init called\n");
446 
447 	mmc_reset(host);
448 
449 	host->version = readw(&host->reg->hcver);
450 	debug("host version = %x\n", host->version);
451 
452 	/* mask all */
453 	writel(0xffffffff, &host->reg->norintstsen);
454 	writel(0xffffffff, &host->reg->norintsigen);
455 
456 	writeb(0xe, &host->reg->timeoutcon);	/* TMCLK * 2^27 */
457 	/*
458 	 * NORMAL Interrupt Status Enable Register init
459 	 * [5] ENSTABUFRDRDY : Buffer Read Ready Status Enable
460 	 * [4] ENSTABUFWTRDY : Buffer write Ready Status Enable
461 	 * [3] ENSTADMAINT   : DMA boundary interrupt
462 	 * [1] ENSTASTANSCMPLT : Transfre Complete Status Enable
463 	 * [0] ENSTACMDCMPLT : Command Complete Status Enable
464 	*/
465 	mask = readl(&host->reg->norintstsen);
466 	mask &= ~(0xffff);
467 	mask |= (TEGRA_MMC_NORINTSTSEN_CMD_COMPLETE |
468 		 TEGRA_MMC_NORINTSTSEN_XFER_COMPLETE |
469 		 TEGRA_MMC_NORINTSTSEN_DMA_INTERRUPT |
470 		 TEGRA_MMC_NORINTSTSEN_BUFFER_WRITE_READY |
471 		 TEGRA_MMC_NORINTSTSEN_BUFFER_READ_READY);
472 	writel(mask, &host->reg->norintstsen);
473 
474 	/*
475 	 * NORMAL Interrupt Signal Enable Register init
476 	 * [1] ENSTACMDCMPLT : Transfer Complete Signal Enable
477 	 */
478 	mask = readl(&host->reg->norintsigen);
479 	mask &= ~(0xffff);
480 	mask |= TEGRA_MMC_NORINTSIGEN_XFER_COMPLETE;
481 	writel(mask, &host->reg->norintsigen);
482 
483 	return 0;
484 }
485 
486 int tegra_mmc_getcd(struct mmc *mmc)
487 {
488 	struct mmc_host *host = (struct mmc_host *)mmc->priv;
489 
490 	debug("tegra_mmc_getcd called\n");
491 
492 	if (fdt_gpio_isvalid(&host->cd_gpio))
493 		return fdtdec_get_gpio(&host->cd_gpio);
494 
495 	return 1;
496 }
497 
498 static int do_mmc_init(int dev_index)
499 {
500 	struct mmc_host *host;
501 	char gpusage[12]; /* "SD/MMCn PWR" or "SD/MMCn CD" */
502 	struct mmc *mmc;
503 
504 	/* DT should have been read & host config filled in */
505 	host = &mmc_host[dev_index];
506 	if (!host->enabled)
507 		return -1;
508 
509 	debug(" do_mmc_init: index %d, bus width %d "
510 		"pwr_gpio %d cd_gpio %d\n",
511 		dev_index, host->width,
512 		host->pwr_gpio.gpio, host->cd_gpio.gpio);
513 
514 	host->clock = 0;
515 	clock_start_periph_pll(host->mmc_id, CLOCK_ID_PERIPH, 20000000);
516 
517 	if (fdt_gpio_isvalid(&host->pwr_gpio)) {
518 		sprintf(gpusage, "SD/MMC%d PWR", dev_index);
519 		gpio_request(host->pwr_gpio.gpio, gpusage);
520 		gpio_direction_output(host->pwr_gpio.gpio, 1);
521 		debug(" Power GPIO name = %s\n", host->pwr_gpio.name);
522 	}
523 
524 	if (fdt_gpio_isvalid(&host->cd_gpio)) {
525 		sprintf(gpusage, "SD/MMC%d CD", dev_index);
526 		gpio_request(host->cd_gpio.gpio, gpusage);
527 		gpio_direction_input(host->cd_gpio.gpio);
528 		debug(" CD GPIO name = %s\n", host->cd_gpio.name);
529 	}
530 
531 	mmc = &mmc_dev[dev_index];
532 
533 	sprintf(mmc->name, "Tegra SD/MMC");
534 	mmc->priv = host;
535 	mmc->send_cmd = mmc_send_cmd;
536 	mmc->set_ios = mmc_set_ios;
537 	mmc->init = mmc_core_init;
538 	mmc->getcd = tegra_mmc_getcd;
539 	mmc->getwp = NULL;
540 
541 	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
542 	mmc->host_caps = 0;
543 	if (host->width == 8)
544 		mmc->host_caps |= MMC_MODE_8BIT;
545 	if (host->width >= 4)
546 		mmc->host_caps |= MMC_MODE_4BIT;
547 	mmc->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS | MMC_MODE_HC;
548 
549 	/*
550 	 * min freq is for card identification, and is the highest
551 	 *  low-speed SDIO card frequency (actually 400KHz)
552 	 * max freq is highest HS eMMC clock as per the SD/MMC spec
553 	 *  (actually 52MHz)
554 	 */
555 	mmc->f_min = 375000;
556 	mmc->f_max = 48000000;
557 
558 	mmc_register(mmc);
559 
560 	return 0;
561 }
562 
563 /**
564  * Get the host address and peripheral ID for a node.
565  *
566  * @param blob		fdt blob
567  * @param node		Device index (0-3)
568  * @param host		Structure to fill in (reg, width, mmc_id)
569  */
570 static int mmc_get_config(const void *blob, int node, struct mmc_host *host)
571 {
572 	debug("%s: node = %d\n", __func__, node);
573 
574 	host->enabled = fdtdec_get_is_enabled(blob, node);
575 
576 	host->reg = (struct tegra_mmc *)fdtdec_get_addr(blob, node, "reg");
577 	if ((fdt_addr_t)host->reg == FDT_ADDR_T_NONE) {
578 		debug("%s: no sdmmc base reg info found\n", __func__);
579 		return -FDT_ERR_NOTFOUND;
580 	}
581 
582 	host->mmc_id = clock_decode_periph_id(blob, node);
583 	if (host->mmc_id == PERIPH_ID_NONE) {
584 		debug("%s: could not decode periph id\n", __func__);
585 		return -FDT_ERR_NOTFOUND;
586 	}
587 
588 	/*
589 	 * NOTE: mmc->bus_width is determined by mmc.c dynamically.
590 	 * TBD: Override it with this value?
591 	 */
592 	host->width = fdtdec_get_int(blob, node, "bus-width", 0);
593 	if (!host->width)
594 		debug("%s: no sdmmc width found\n", __func__);
595 
596 	/* These GPIOs are optional */
597 	fdtdec_decode_gpio(blob, node, "cd-gpios", &host->cd_gpio);
598 	fdtdec_decode_gpio(blob, node, "wp-gpios", &host->wp_gpio);
599 	fdtdec_decode_gpio(blob, node, "power-gpios", &host->pwr_gpio);
600 
601 	debug("%s: found controller at %p, width = %d, periph_id = %d\n",
602 		__func__, host->reg, host->width, host->mmc_id);
603 	return 0;
604 }
605 
606 /*
607  * Process a list of nodes, adding them to our list of SDMMC ports.
608  *
609  * @param blob          fdt blob
610  * @param node_list     list of nodes to process (any <=0 are ignored)
611  * @param count         number of nodes to process
612  * @return 0 if ok, -1 on error
613  */
614 static int process_nodes(const void *blob, int node_list[], int count)
615 {
616 	struct mmc_host *host;
617 	int i, node;
618 
619 	debug("%s: count = %d\n", __func__, count);
620 
621 	/* build mmc_host[] for each controller */
622 	for (i = 0; i < count; i++) {
623 		node = node_list[i];
624 		if (node <= 0)
625 			continue;
626 
627 		host = &mmc_host[i];
628 		host->id = i;
629 
630 		if (mmc_get_config(blob, node, host)) {
631 			printf("%s: failed to decode dev %d\n",	__func__, i);
632 			return -1;
633 		}
634 		do_mmc_init(i);
635 	}
636 	return 0;
637 }
638 
639 void tegra_mmc_init(void)
640 {
641 	int node_list[MAX_HOSTS], count;
642 	const void *blob = gd->fdt_blob;
643 	debug("%s entry\n", __func__);
644 
645 	count = fdtdec_find_aliases_for_id(blob, "sdhci",
646 		COMPAT_NVIDIA_TEGRA20_SDMMC, node_list, MAX_HOSTS);
647 	debug("%s: count of sdhci nodes is %d\n", __func__, count);
648 
649 	if (process_nodes(blob, node_list, count)) {
650 		printf("%s: Error processing mmc node(s)!\n", __func__);
651 		return;
652 	}
653 }
654