xref: /openbmc/u-boot/drivers/mmc/tegra_mmc.c (revision b9553986)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2009 SAMSUNG Electronics
4  * Minkyu Kang <mk7.kang@samsung.com>
5  * Jaehoon Chung <jh80.chung@samsung.com>
6  * Portions Copyright 2011-2016 NVIDIA Corporation
7  */
8 
9 #include <bouncebuf.h>
10 #include <common.h>
11 #include <dm.h>
12 #include <errno.h>
13 #include <mmc.h>
14 #include <asm/gpio.h>
15 #include <asm/io.h>
16 #include <asm/arch-tegra/tegra_mmc.h>
17 
18 struct tegra_mmc_plat {
19 	struct mmc_config cfg;
20 	struct mmc mmc;
21 };
22 
23 struct tegra_mmc_priv {
24 	struct tegra_mmc *reg;
25 	struct reset_ctl reset_ctl;
26 	struct clk clk;
27 	struct gpio_desc cd_gpio;	/* Change Detect GPIO */
28 	struct gpio_desc pwr_gpio;	/* Power GPIO */
29 	struct gpio_desc wp_gpio;	/* Write Protect GPIO */
30 	unsigned int version;	/* SDHCI spec. version */
31 	unsigned int clock;	/* Current clock (MHz) */
32 };
33 
34 static void tegra_mmc_set_power(struct tegra_mmc_priv *priv,
35 				unsigned short power)
36 {
37 	u8 pwr = 0;
38 	debug("%s: power = %x\n", __func__, power);
39 
40 	if (power != (unsigned short)-1) {
41 		switch (1 << power) {
42 		case MMC_VDD_165_195:
43 			pwr = TEGRA_MMC_PWRCTL_SD_BUS_VOLTAGE_V1_8;
44 			break;
45 		case MMC_VDD_29_30:
46 		case MMC_VDD_30_31:
47 			pwr = TEGRA_MMC_PWRCTL_SD_BUS_VOLTAGE_V3_0;
48 			break;
49 		case MMC_VDD_32_33:
50 		case MMC_VDD_33_34:
51 			pwr = TEGRA_MMC_PWRCTL_SD_BUS_VOLTAGE_V3_3;
52 			break;
53 		}
54 	}
55 	debug("%s: pwr = %X\n", __func__, pwr);
56 
57 	/* Set the bus voltage first (if any) */
58 	writeb(pwr, &priv->reg->pwrcon);
59 	if (pwr == 0)
60 		return;
61 
62 	/* Now enable bus power */
63 	pwr |= TEGRA_MMC_PWRCTL_SD_BUS_POWER;
64 	writeb(pwr, &priv->reg->pwrcon);
65 }
66 
67 static void tegra_mmc_prepare_data(struct tegra_mmc_priv *priv,
68 				   struct mmc_data *data,
69 				   struct bounce_buffer *bbstate)
70 {
71 	unsigned char ctrl;
72 
73 
74 	debug("buf: %p (%p), data->blocks: %u, data->blocksize: %u\n",
75 		bbstate->bounce_buffer, bbstate->user_buffer, data->blocks,
76 		data->blocksize);
77 
78 	writel((u32)(unsigned long)bbstate->bounce_buffer, &priv->reg->sysad);
79 	/*
80 	 * DMASEL[4:3]
81 	 * 00 = Selects SDMA
82 	 * 01 = Reserved
83 	 * 10 = Selects 32-bit Address ADMA2
84 	 * 11 = Selects 64-bit Address ADMA2
85 	 */
86 	ctrl = readb(&priv->reg->hostctl);
87 	ctrl &= ~TEGRA_MMC_HOSTCTL_DMASEL_MASK;
88 	ctrl |= TEGRA_MMC_HOSTCTL_DMASEL_SDMA;
89 	writeb(ctrl, &priv->reg->hostctl);
90 
91 	/* We do not handle DMA boundaries, so set it to max (512 KiB) */
92 	writew((7 << 12) | (data->blocksize & 0xFFF), &priv->reg->blksize);
93 	writew(data->blocks, &priv->reg->blkcnt);
94 }
95 
96 static void tegra_mmc_set_transfer_mode(struct tegra_mmc_priv *priv,
97 					struct mmc_data *data)
98 {
99 	unsigned short mode;
100 	debug(" mmc_set_transfer_mode called\n");
101 	/*
102 	 * TRNMOD
103 	 * MUL1SIN0[5]	: Multi/Single Block Select
104 	 * RD1WT0[4]	: Data Transfer Direction Select
105 	 *	1 = read
106 	 *	0 = write
107 	 * ENACMD12[2]	: Auto CMD12 Enable
108 	 * ENBLKCNT[1]	: Block Count Enable
109 	 * ENDMA[0]	: DMA Enable
110 	 */
111 	mode = (TEGRA_MMC_TRNMOD_DMA_ENABLE |
112 		TEGRA_MMC_TRNMOD_BLOCK_COUNT_ENABLE);
113 
114 	if (data->blocks > 1)
115 		mode |= TEGRA_MMC_TRNMOD_MULTI_BLOCK_SELECT;
116 
117 	if (data->flags & MMC_DATA_READ)
118 		mode |= TEGRA_MMC_TRNMOD_DATA_XFER_DIR_SEL_READ;
119 
120 	writew(mode, &priv->reg->trnmod);
121 }
122 
123 static int tegra_mmc_wait_inhibit(struct tegra_mmc_priv *priv,
124 				  struct mmc_cmd *cmd,
125 				  struct mmc_data *data,
126 				  unsigned int timeout)
127 {
128 	/*
129 	 * PRNSTS
130 	 * CMDINHDAT[1] : Command Inhibit (DAT)
131 	 * CMDINHCMD[0] : Command Inhibit (CMD)
132 	 */
133 	unsigned int mask = TEGRA_MMC_PRNSTS_CMD_INHIBIT_CMD;
134 
135 	/*
136 	 * We shouldn't wait for data inhibit for stop commands, even
137 	 * though they might use busy signaling
138 	 */
139 	if ((data == NULL) && (cmd->resp_type & MMC_RSP_BUSY))
140 		mask |= TEGRA_MMC_PRNSTS_CMD_INHIBIT_DAT;
141 
142 	while (readl(&priv->reg->prnsts) & mask) {
143 		if (timeout == 0) {
144 			printf("%s: timeout error\n", __func__);
145 			return -1;
146 		}
147 		timeout--;
148 		udelay(1000);
149 	}
150 
151 	return 0;
152 }
153 
154 static int tegra_mmc_send_cmd_bounced(struct udevice *dev, struct mmc_cmd *cmd,
155 				      struct mmc_data *data,
156 				      struct bounce_buffer *bbstate)
157 {
158 	struct tegra_mmc_priv *priv = dev_get_priv(dev);
159 	int flags, i;
160 	int result;
161 	unsigned int mask = 0;
162 	unsigned int retry = 0x100000;
163 	debug(" mmc_send_cmd called\n");
164 
165 	result = tegra_mmc_wait_inhibit(priv, cmd, data, 10 /* ms */);
166 
167 	if (result < 0)
168 		return result;
169 
170 	if (data)
171 		tegra_mmc_prepare_data(priv, data, bbstate);
172 
173 	debug("cmd->arg: %08x\n", cmd->cmdarg);
174 	writel(cmd->cmdarg, &priv->reg->argument);
175 
176 	if (data)
177 		tegra_mmc_set_transfer_mode(priv, data);
178 
179 	if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY))
180 		return -1;
181 
182 	/*
183 	 * CMDREG
184 	 * CMDIDX[13:8]	: Command index
185 	 * DATAPRNT[5]	: Data Present Select
186 	 * ENCMDIDX[4]	: Command Index Check Enable
187 	 * ENCMDCRC[3]	: Command CRC Check Enable
188 	 * RSPTYP[1:0]
189 	 *	00 = No Response
190 	 *	01 = Length 136
191 	 *	10 = Length 48
192 	 *	11 = Length 48 Check busy after response
193 	 */
194 	if (!(cmd->resp_type & MMC_RSP_PRESENT))
195 		flags = TEGRA_MMC_CMDREG_RESP_TYPE_SELECT_NO_RESPONSE;
196 	else if (cmd->resp_type & MMC_RSP_136)
197 		flags = TEGRA_MMC_CMDREG_RESP_TYPE_SELECT_LENGTH_136;
198 	else if (cmd->resp_type & MMC_RSP_BUSY)
199 		flags = TEGRA_MMC_CMDREG_RESP_TYPE_SELECT_LENGTH_48_BUSY;
200 	else
201 		flags = TEGRA_MMC_CMDREG_RESP_TYPE_SELECT_LENGTH_48;
202 
203 	if (cmd->resp_type & MMC_RSP_CRC)
204 		flags |= TEGRA_MMC_TRNMOD_CMD_CRC_CHECK;
205 	if (cmd->resp_type & MMC_RSP_OPCODE)
206 		flags |= TEGRA_MMC_TRNMOD_CMD_INDEX_CHECK;
207 	if (data)
208 		flags |= TEGRA_MMC_TRNMOD_DATA_PRESENT_SELECT_DATA_TRANSFER;
209 
210 	debug("cmd: %d\n", cmd->cmdidx);
211 
212 	writew((cmd->cmdidx << 8) | flags, &priv->reg->cmdreg);
213 
214 	for (i = 0; i < retry; i++) {
215 		mask = readl(&priv->reg->norintsts);
216 		/* Command Complete */
217 		if (mask & TEGRA_MMC_NORINTSTS_CMD_COMPLETE) {
218 			if (!data)
219 				writel(mask, &priv->reg->norintsts);
220 			break;
221 		}
222 	}
223 
224 	if (i == retry) {
225 		printf("%s: waiting for status update\n", __func__);
226 		writel(mask, &priv->reg->norintsts);
227 		return -ETIMEDOUT;
228 	}
229 
230 	if (mask & TEGRA_MMC_NORINTSTS_CMD_TIMEOUT) {
231 		/* Timeout Error */
232 		debug("timeout: %08x cmd %d\n", mask, cmd->cmdidx);
233 		writel(mask, &priv->reg->norintsts);
234 		return -ETIMEDOUT;
235 	} else if (mask & TEGRA_MMC_NORINTSTS_ERR_INTERRUPT) {
236 		/* Error Interrupt */
237 		debug("error: %08x cmd %d\n", mask, cmd->cmdidx);
238 		writel(mask, &priv->reg->norintsts);
239 		return -1;
240 	}
241 
242 	if (cmd->resp_type & MMC_RSP_PRESENT) {
243 		if (cmd->resp_type & MMC_RSP_136) {
244 			/* CRC is stripped so we need to do some shifting. */
245 			for (i = 0; i < 4; i++) {
246 				unsigned long offset = (unsigned long)
247 					(&priv->reg->rspreg3 - i);
248 				cmd->response[i] = readl(offset) << 8;
249 
250 				if (i != 3) {
251 					cmd->response[i] |=
252 						readb(offset - 1);
253 				}
254 				debug("cmd->resp[%d]: %08x\n",
255 						i, cmd->response[i]);
256 			}
257 		} else if (cmd->resp_type & MMC_RSP_BUSY) {
258 			for (i = 0; i < retry; i++) {
259 				/* PRNTDATA[23:20] : DAT[3:0] Line Signal */
260 				if (readl(&priv->reg->prnsts)
261 					& (1 << 20))	/* DAT[0] */
262 					break;
263 			}
264 
265 			if (i == retry) {
266 				printf("%s: card is still busy\n", __func__);
267 				writel(mask, &priv->reg->norintsts);
268 				return -ETIMEDOUT;
269 			}
270 
271 			cmd->response[0] = readl(&priv->reg->rspreg0);
272 			debug("cmd->resp[0]: %08x\n", cmd->response[0]);
273 		} else {
274 			cmd->response[0] = readl(&priv->reg->rspreg0);
275 			debug("cmd->resp[0]: %08x\n", cmd->response[0]);
276 		}
277 	}
278 
279 	if (data) {
280 		unsigned long	start = get_timer(0);
281 
282 		while (1) {
283 			mask = readl(&priv->reg->norintsts);
284 
285 			if (mask & TEGRA_MMC_NORINTSTS_ERR_INTERRUPT) {
286 				/* Error Interrupt */
287 				writel(mask, &priv->reg->norintsts);
288 				printf("%s: error during transfer: 0x%08x\n",
289 						__func__, mask);
290 				return -1;
291 			} else if (mask & TEGRA_MMC_NORINTSTS_DMA_INTERRUPT) {
292 				/*
293 				 * DMA Interrupt, restart the transfer where
294 				 * it was interrupted.
295 				 */
296 				unsigned int address = readl(&priv->reg->sysad);
297 
298 				debug("DMA end\n");
299 				writel(TEGRA_MMC_NORINTSTS_DMA_INTERRUPT,
300 				       &priv->reg->norintsts);
301 				writel(address, &priv->reg->sysad);
302 			} else if (mask & TEGRA_MMC_NORINTSTS_XFER_COMPLETE) {
303 				/* Transfer Complete */
304 				debug("r/w is done\n");
305 				break;
306 			} else if (get_timer(start) > 8000UL) {
307 				writel(mask, &priv->reg->norintsts);
308 				printf("%s: MMC Timeout\n"
309 				       "    Interrupt status        0x%08x\n"
310 				       "    Interrupt status enable 0x%08x\n"
311 				       "    Interrupt signal enable 0x%08x\n"
312 				       "    Present status          0x%08x\n",
313 				       __func__, mask,
314 				       readl(&priv->reg->norintstsen),
315 				       readl(&priv->reg->norintsigen),
316 				       readl(&priv->reg->prnsts));
317 				return -1;
318 			}
319 		}
320 		writel(mask, &priv->reg->norintsts);
321 	}
322 
323 	udelay(1000);
324 	return 0;
325 }
326 
327 static int tegra_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
328 			      struct mmc_data *data)
329 {
330 	void *buf;
331 	unsigned int bbflags;
332 	size_t len;
333 	struct bounce_buffer bbstate;
334 	int ret;
335 
336 	if (data) {
337 		if (data->flags & MMC_DATA_READ) {
338 			buf = data->dest;
339 			bbflags = GEN_BB_WRITE;
340 		} else {
341 			buf = (void *)data->src;
342 			bbflags = GEN_BB_READ;
343 		}
344 		len = data->blocks * data->blocksize;
345 
346 		bounce_buffer_start(&bbstate, buf, len, bbflags);
347 	}
348 
349 	ret = tegra_mmc_send_cmd_bounced(dev, cmd, data, &bbstate);
350 
351 	if (data)
352 		bounce_buffer_stop(&bbstate);
353 
354 	return ret;
355 }
356 
357 static void tegra_mmc_change_clock(struct tegra_mmc_priv *priv, uint clock)
358 {
359 	ulong rate;
360 	int div;
361 	unsigned short clk;
362 	unsigned long timeout;
363 
364 	debug(" mmc_change_clock called\n");
365 
366 	/*
367 	 * Change Tegra SDMMCx clock divisor here. Source is PLLP_OUT0
368 	 */
369 	if (clock == 0)
370 		goto out;
371 
372 	rate = clk_set_rate(&priv->clk, clock);
373 	div = (rate + clock - 1) / clock;
374 	debug("div = %d\n", div);
375 
376 	writew(0, &priv->reg->clkcon);
377 
378 	/*
379 	 * CLKCON
380 	 * SELFREQ[15:8]	: base clock divided by value
381 	 * ENSDCLK[2]		: SD Clock Enable
382 	 * STBLINTCLK[1]	: Internal Clock Stable
383 	 * ENINTCLK[0]		: Internal Clock Enable
384 	 */
385 	div >>= 1;
386 	clk = ((div << TEGRA_MMC_CLKCON_SDCLK_FREQ_SEL_SHIFT) |
387 	       TEGRA_MMC_CLKCON_INTERNAL_CLOCK_ENABLE);
388 	writew(clk, &priv->reg->clkcon);
389 
390 	/* Wait max 10 ms */
391 	timeout = 10;
392 	while (!(readw(&priv->reg->clkcon) &
393 		 TEGRA_MMC_CLKCON_INTERNAL_CLOCK_STABLE)) {
394 		if (timeout == 0) {
395 			printf("%s: timeout error\n", __func__);
396 			return;
397 		}
398 		timeout--;
399 		udelay(1000);
400 	}
401 
402 	clk |= TEGRA_MMC_CLKCON_SD_CLOCK_ENABLE;
403 	writew(clk, &priv->reg->clkcon);
404 
405 	debug("mmc_change_clock: clkcon = %08X\n", clk);
406 
407 out:
408 	priv->clock = clock;
409 }
410 
411 static int tegra_mmc_set_ios(struct udevice *dev)
412 {
413 	struct tegra_mmc_priv *priv = dev_get_priv(dev);
414 	struct mmc *mmc = mmc_get_mmc_dev(dev);
415 	unsigned char ctrl;
416 	debug(" mmc_set_ios called\n");
417 
418 	debug("bus_width: %x, clock: %d\n", mmc->bus_width, mmc->clock);
419 
420 	/* Change clock first */
421 	tegra_mmc_change_clock(priv, mmc->clock);
422 
423 	ctrl = readb(&priv->reg->hostctl);
424 
425 	/*
426 	 * WIDE8[5]
427 	 * 0 = Depend on WIDE4
428 	 * 1 = 8-bit mode
429 	 * WIDE4[1]
430 	 * 1 = 4-bit mode
431 	 * 0 = 1-bit mode
432 	 */
433 	if (mmc->bus_width == 8)
434 		ctrl |= (1 << 5);
435 	else if (mmc->bus_width == 4)
436 		ctrl |= (1 << 1);
437 	else
438 		ctrl &= ~(1 << 1 | 1 << 5);
439 
440 	writeb(ctrl, &priv->reg->hostctl);
441 	debug("mmc_set_ios: hostctl = %08X\n", ctrl);
442 
443 	return 0;
444 }
445 
446 static void tegra_mmc_pad_init(struct tegra_mmc_priv *priv)
447 {
448 #if defined(CONFIG_TEGRA30)
449 	u32 val;
450 
451 	debug("%s: sdmmc address = %08x\n", __func__, (unsigned int)priv->reg);
452 
453 	/* Set the pad drive strength for SDMMC1 or 3 only */
454 	if (priv->reg != (void *)0x78000000 &&
455 	    priv->reg != (void *)0x78000400) {
456 		debug("%s: settings are only valid for SDMMC1/SDMMC3!\n",
457 		      __func__);
458 		return;
459 	}
460 
461 	val = readl(&priv->reg->sdmemcmppadctl);
462 	val &= 0xFFFFFFF0;
463 	val |= MEMCOMP_PADCTRL_VREF;
464 	writel(val, &priv->reg->sdmemcmppadctl);
465 
466 	val = readl(&priv->reg->autocalcfg);
467 	val &= 0xFFFF0000;
468 	val |= AUTO_CAL_PU_OFFSET | AUTO_CAL_PD_OFFSET | AUTO_CAL_ENABLED;
469 	writel(val, &priv->reg->autocalcfg);
470 #endif
471 }
472 
473 static void tegra_mmc_reset(struct tegra_mmc_priv *priv, struct mmc *mmc)
474 {
475 	unsigned int timeout;
476 	debug(" mmc_reset called\n");
477 
478 	/*
479 	 * RSTALL[0] : Software reset for all
480 	 * 1 = reset
481 	 * 0 = work
482 	 */
483 	writeb(TEGRA_MMC_SWRST_SW_RESET_FOR_ALL, &priv->reg->swrst);
484 
485 	priv->clock = 0;
486 
487 	/* Wait max 100 ms */
488 	timeout = 100;
489 
490 	/* hw clears the bit when it's done */
491 	while (readb(&priv->reg->swrst) & TEGRA_MMC_SWRST_SW_RESET_FOR_ALL) {
492 		if (timeout == 0) {
493 			printf("%s: timeout error\n", __func__);
494 			return;
495 		}
496 		timeout--;
497 		udelay(1000);
498 	}
499 
500 	/* Set SD bus voltage & enable bus power */
501 	tegra_mmc_set_power(priv, fls(mmc->cfg->voltages) - 1);
502 	debug("%s: power control = %02X, host control = %02X\n", __func__,
503 		readb(&priv->reg->pwrcon), readb(&priv->reg->hostctl));
504 
505 	/* Make sure SDIO pads are set up */
506 	tegra_mmc_pad_init(priv);
507 }
508 
509 static int tegra_mmc_init(struct udevice *dev)
510 {
511 	struct tegra_mmc_priv *priv = dev_get_priv(dev);
512 	struct mmc *mmc = mmc_get_mmc_dev(dev);
513 	unsigned int mask;
514 	debug(" tegra_mmc_init called\n");
515 
516 	tegra_mmc_reset(priv, mmc);
517 
518 #if defined(CONFIG_TEGRA124_MMC_DISABLE_EXT_LOOPBACK)
519 	/*
520 	 * Disable the external clock loopback and use the internal one on
521 	 * SDMMC3 as per the SDMMC_VENDOR_MISC_CNTRL_0 register's SDMMC_SPARE1
522 	 * bits being set to 0xfffd according to the TRM.
523 	 *
524 	 * TODO(marcel.ziswiler@toradex.com): Move to device tree controlled
525 	 * approach once proper kernel integration made it mainline.
526 	 */
527 	if (priv->reg == (void *)0x700b0400) {
528 		mask = readl(&priv->reg->venmiscctl);
529 		mask &= ~TEGRA_MMC_MISCON_ENABLE_EXT_LOOPBACK;
530 		writel(mask, &priv->reg->venmiscctl);
531 	}
532 #endif
533 
534 	priv->version = readw(&priv->reg->hcver);
535 	debug("host version = %x\n", priv->version);
536 
537 	/* mask all */
538 	writel(0xffffffff, &priv->reg->norintstsen);
539 	writel(0xffffffff, &priv->reg->norintsigen);
540 
541 	writeb(0xe, &priv->reg->timeoutcon);	/* TMCLK * 2^27 */
542 	/*
543 	 * NORMAL Interrupt Status Enable Register init
544 	 * [5] ENSTABUFRDRDY : Buffer Read Ready Status Enable
545 	 * [4] ENSTABUFWTRDY : Buffer write Ready Status Enable
546 	 * [3] ENSTADMAINT   : DMA boundary interrupt
547 	 * [1] ENSTASTANSCMPLT : Transfre Complete Status Enable
548 	 * [0] ENSTACMDCMPLT : Command Complete Status Enable
549 	*/
550 	mask = readl(&priv->reg->norintstsen);
551 	mask &= ~(0xffff);
552 	mask |= (TEGRA_MMC_NORINTSTSEN_CMD_COMPLETE |
553 		 TEGRA_MMC_NORINTSTSEN_XFER_COMPLETE |
554 		 TEGRA_MMC_NORINTSTSEN_DMA_INTERRUPT |
555 		 TEGRA_MMC_NORINTSTSEN_BUFFER_WRITE_READY |
556 		 TEGRA_MMC_NORINTSTSEN_BUFFER_READ_READY);
557 	writel(mask, &priv->reg->norintstsen);
558 
559 	/*
560 	 * NORMAL Interrupt Signal Enable Register init
561 	 * [1] ENSTACMDCMPLT : Transfer Complete Signal Enable
562 	 */
563 	mask = readl(&priv->reg->norintsigen);
564 	mask &= ~(0xffff);
565 	mask |= TEGRA_MMC_NORINTSIGEN_XFER_COMPLETE;
566 	writel(mask, &priv->reg->norintsigen);
567 
568 	return 0;
569 }
570 
571 static int tegra_mmc_getcd(struct udevice *dev)
572 {
573 	struct tegra_mmc_priv *priv = dev_get_priv(dev);
574 
575 	debug("tegra_mmc_getcd called\n");
576 
577 	if (dm_gpio_is_valid(&priv->cd_gpio))
578 		return dm_gpio_get_value(&priv->cd_gpio);
579 
580 	return 1;
581 }
582 
583 static const struct dm_mmc_ops tegra_mmc_ops = {
584 	.send_cmd	= tegra_mmc_send_cmd,
585 	.set_ios	= tegra_mmc_set_ios,
586 	.get_cd		= tegra_mmc_getcd,
587 };
588 
589 static int tegra_mmc_probe(struct udevice *dev)
590 {
591 	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
592 	struct tegra_mmc_plat *plat = dev_get_platdata(dev);
593 	struct tegra_mmc_priv *priv = dev_get_priv(dev);
594 	struct mmc_config *cfg = &plat->cfg;
595 	int bus_width, ret;
596 
597 	cfg->name = dev->name;
598 
599 	bus_width = dev_read_u32_default(dev, "bus-width", 1);
600 
601 	cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
602 	cfg->host_caps = 0;
603 	if (bus_width == 8)
604 		cfg->host_caps |= MMC_MODE_8BIT;
605 	if (bus_width >= 4)
606 		cfg->host_caps |= MMC_MODE_4BIT;
607 	cfg->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
608 
609 	/*
610 	 * min freq is for card identification, and is the highest
611 	 *  low-speed SDIO card frequency (actually 400KHz)
612 	 * max freq is highest HS eMMC clock as per the SD/MMC spec
613 	 *  (actually 52MHz)
614 	 */
615 	cfg->f_min = 375000;
616 	cfg->f_max = 48000000;
617 
618 	cfg->b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT;
619 
620 	priv->reg = (void *)dev_read_addr(dev);
621 
622 	ret = reset_get_by_name(dev, "sdhci", &priv->reset_ctl);
623 	if (ret) {
624 		debug("reset_get_by_name() failed: %d\n", ret);
625 		return ret;
626 	}
627 	ret = clk_get_by_index(dev, 0, &priv->clk);
628 	if (ret) {
629 		debug("clk_get_by_index() failed: %d\n", ret);
630 		return ret;
631 	}
632 
633 	ret = reset_assert(&priv->reset_ctl);
634 	if (ret)
635 		return ret;
636 	ret = clk_enable(&priv->clk);
637 	if (ret)
638 		return ret;
639 	ret = clk_set_rate(&priv->clk, 20000000);
640 	if (IS_ERR_VALUE(ret))
641 		return ret;
642 	ret = reset_deassert(&priv->reset_ctl);
643 	if (ret)
644 		return ret;
645 
646 	/* These GPIOs are optional */
647 	gpio_request_by_name(dev, "cd-gpios", 0, &priv->cd_gpio, GPIOD_IS_IN);
648 	gpio_request_by_name(dev, "wp-gpios", 0, &priv->wp_gpio, GPIOD_IS_IN);
649 	gpio_request_by_name(dev, "power-gpios", 0, &priv->pwr_gpio,
650 			     GPIOD_IS_OUT);
651 	if (dm_gpio_is_valid(&priv->pwr_gpio))
652 		dm_gpio_set_value(&priv->pwr_gpio, 1);
653 
654 	upriv->mmc = &plat->mmc;
655 
656 	return tegra_mmc_init(dev);
657 }
658 
659 static int tegra_mmc_bind(struct udevice *dev)
660 {
661 	struct tegra_mmc_plat *plat = dev_get_platdata(dev);
662 
663 	return mmc_bind(dev, &plat->mmc, &plat->cfg);
664 }
665 
666 static const struct udevice_id tegra_mmc_ids[] = {
667 	{ .compatible = "nvidia,tegra20-sdhci" },
668 	{ .compatible = "nvidia,tegra30-sdhci" },
669 	{ .compatible = "nvidia,tegra114-sdhci" },
670 	{ .compatible = "nvidia,tegra124-sdhci" },
671 	{ .compatible = "nvidia,tegra210-sdhci" },
672 	{ .compatible = "nvidia,tegra186-sdhci" },
673 	{ }
674 };
675 
676 U_BOOT_DRIVER(tegra_mmc_drv) = {
677 	.name		= "tegra_mmc",
678 	.id		= UCLASS_MMC,
679 	.of_match	= tegra_mmc_ids,
680 	.bind		= tegra_mmc_bind,
681 	.probe		= tegra_mmc_probe,
682 	.ops		= &tegra_mmc_ops,
683 	.platdata_auto_alloc_size = sizeof(struct tegra_mmc_plat),
684 	.priv_auto_alloc_size = sizeof(struct tegra_mmc_priv),
685 };
686