xref: /openbmc/linux/drivers/mmc/host/sdhci-tegra.c (revision 726df1d5)
1 /*
2  * Copyright (C) 2010 Google, Inc.
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 
15 #include <linux/delay.h>
16 #include <linux/err.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/platform_device.h>
20 #include <linux/clk.h>
21 #include <linux/io.h>
22 #include <linux/of.h>
23 #include <linux/of_device.h>
24 #include <linux/reset.h>
25 #include <linux/mmc/card.h>
26 #include <linux/mmc/host.h>
27 #include <linux/mmc/mmc.h>
28 #include <linux/mmc/slot-gpio.h>
29 #include <linux/gpio/consumer.h>
30 
31 #include "sdhci-pltfm.h"
32 
33 /* Tegra SDHOST controller vendor register definitions */
34 #define SDHCI_TEGRA_VENDOR_CLOCK_CTRL			0x100
35 #define SDHCI_CLOCK_CTRL_TAP_MASK			0x00ff0000
36 #define SDHCI_CLOCK_CTRL_TAP_SHIFT			16
37 #define SDHCI_CLOCK_CTRL_SDR50_TUNING_OVERRIDE		BIT(5)
38 #define SDHCI_CLOCK_CTRL_PADPIPE_CLKEN_OVERRIDE		BIT(3)
39 #define SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE	BIT(2)
40 
41 #define SDHCI_TEGRA_VENDOR_MISC_CTRL		0x120
42 #define SDHCI_MISC_CTRL_ENABLE_SDR104		0x8
43 #define SDHCI_MISC_CTRL_ENABLE_SDR50		0x10
44 #define SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300	0x20
45 #define SDHCI_MISC_CTRL_ENABLE_DDR50		0x200
46 
47 #define SDHCI_TEGRA_AUTO_CAL_CONFIG		0x1e4
48 #define SDHCI_AUTO_CAL_START			BIT(31)
49 #define SDHCI_AUTO_CAL_ENABLE			BIT(29)
50 
51 #define NVQUIRK_FORCE_SDHCI_SPEC_200	BIT(0)
52 #define NVQUIRK_ENABLE_BLOCK_GAP_DET	BIT(1)
53 #define NVQUIRK_ENABLE_SDHCI_SPEC_300	BIT(2)
54 #define NVQUIRK_ENABLE_SDR50		BIT(3)
55 #define NVQUIRK_ENABLE_SDR104		BIT(4)
56 #define NVQUIRK_ENABLE_DDR50		BIT(5)
57 #define NVQUIRK_HAS_PADCALIB		BIT(6)
58 
59 struct sdhci_tegra_soc_data {
60 	const struct sdhci_pltfm_data *pdata;
61 	u32 nvquirks;
62 };
63 
64 struct sdhci_tegra {
65 	const struct sdhci_tegra_soc_data *soc_data;
66 	struct gpio_desc *power_gpio;
67 	bool ddr_signaling;
68 	bool pad_calib_required;
69 
70 	struct reset_control *rst;
71 };
72 
73 static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
74 {
75 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
76 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
77 	const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
78 
79 	if (unlikely((soc_data->nvquirks & NVQUIRK_FORCE_SDHCI_SPEC_200) &&
80 			(reg == SDHCI_HOST_VERSION))) {
81 		/* Erratum: Version register is invalid in HW. */
82 		return SDHCI_SPEC_200;
83 	}
84 
85 	return readw(host->ioaddr + reg);
86 }
87 
88 static void tegra_sdhci_writew(struct sdhci_host *host, u16 val, int reg)
89 {
90 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
91 
92 	switch (reg) {
93 	case SDHCI_TRANSFER_MODE:
94 		/*
95 		 * Postpone this write, we must do it together with a
96 		 * command write that is down below.
97 		 */
98 		pltfm_host->xfer_mode_shadow = val;
99 		return;
100 	case SDHCI_COMMAND:
101 		writel((val << 16) | pltfm_host->xfer_mode_shadow,
102 			host->ioaddr + SDHCI_TRANSFER_MODE);
103 		return;
104 	}
105 
106 	writew(val, host->ioaddr + reg);
107 }
108 
109 static void tegra_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
110 {
111 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
112 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
113 	const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
114 
115 	/* Seems like we're getting spurious timeout and crc errors, so
116 	 * disable signalling of them. In case of real errors software
117 	 * timers should take care of eventually detecting them.
118 	 */
119 	if (unlikely(reg == SDHCI_SIGNAL_ENABLE))
120 		val &= ~(SDHCI_INT_TIMEOUT|SDHCI_INT_CRC);
121 
122 	writel(val, host->ioaddr + reg);
123 
124 	if (unlikely((soc_data->nvquirks & NVQUIRK_ENABLE_BLOCK_GAP_DET) &&
125 			(reg == SDHCI_INT_ENABLE))) {
126 		/* Erratum: Must enable block gap interrupt detection */
127 		u8 gap_ctrl = readb(host->ioaddr + SDHCI_BLOCK_GAP_CONTROL);
128 		if (val & SDHCI_INT_CARD_INT)
129 			gap_ctrl |= 0x8;
130 		else
131 			gap_ctrl &= ~0x8;
132 		writeb(gap_ctrl, host->ioaddr + SDHCI_BLOCK_GAP_CONTROL);
133 	}
134 }
135 
136 static unsigned int tegra_sdhci_get_ro(struct sdhci_host *host)
137 {
138 	return mmc_gpio_get_ro(host->mmc);
139 }
140 
141 static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
142 {
143 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
144 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
145 	const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
146 	u32 misc_ctrl, clk_ctrl;
147 
148 	sdhci_reset(host, mask);
149 
150 	if (!(mask & SDHCI_RESET_ALL))
151 		return;
152 
153 	misc_ctrl = sdhci_readl(host, SDHCI_TEGRA_VENDOR_MISC_CTRL);
154 	clk_ctrl = sdhci_readl(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
155 
156 	misc_ctrl &= ~(SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300 |
157 		       SDHCI_MISC_CTRL_ENABLE_SDR50 |
158 		       SDHCI_MISC_CTRL_ENABLE_DDR50 |
159 		       SDHCI_MISC_CTRL_ENABLE_SDR104);
160 
161 	clk_ctrl &= ~SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE;
162 
163 	/*
164 	 * If the board does not define a regulator for the SDHCI
165 	 * IO voltage, then don't advertise support for UHS modes
166 	 * even if the device supports it because the IO voltage
167 	 * cannot be configured.
168 	 */
169 	if (!IS_ERR(host->mmc->supply.vqmmc)) {
170 		/* Erratum: Enable SDHCI spec v3.00 support */
171 		if (soc_data->nvquirks & NVQUIRK_ENABLE_SDHCI_SPEC_300)
172 			misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300;
173 		/* Advertise UHS modes as supported by host */
174 		if (soc_data->nvquirks & NVQUIRK_ENABLE_SDR50)
175 			misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDR50;
176 		if (soc_data->nvquirks & NVQUIRK_ENABLE_DDR50)
177 			misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_DDR50;
178 		if (soc_data->nvquirks & NVQUIRK_ENABLE_SDR104)
179 			misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDR104;
180 		if (soc_data->nvquirks & SDHCI_MISC_CTRL_ENABLE_SDR50)
181 			clk_ctrl |= SDHCI_CLOCK_CTRL_SDR50_TUNING_OVERRIDE;
182 	}
183 
184 	sdhci_writel(host, misc_ctrl, SDHCI_TEGRA_VENDOR_MISC_CTRL);
185 	sdhci_writel(host, clk_ctrl, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
186 
187 	if (soc_data->nvquirks & NVQUIRK_HAS_PADCALIB)
188 		tegra_host->pad_calib_required = true;
189 
190 	tegra_host->ddr_signaling = false;
191 }
192 
193 static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
194 {
195 	u32 val;
196 
197 	mdelay(1);
198 
199 	val = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
200 	val |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
201 	sdhci_writel(host,val, SDHCI_TEGRA_AUTO_CAL_CONFIG);
202 }
203 
204 static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
205 {
206 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
207 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
208 	unsigned long host_clk;
209 
210 	if (!clock)
211 		return sdhci_set_clock(host, clock);
212 
213 	host_clk = tegra_host->ddr_signaling ? clock * 2 : clock;
214 	clk_set_rate(pltfm_host->clk, host_clk);
215 	host->max_clk = clk_get_rate(pltfm_host->clk);
216 
217 	sdhci_set_clock(host, clock);
218 
219 	if (tegra_host->pad_calib_required) {
220 		tegra_sdhci_pad_autocalib(host);
221 		tegra_host->pad_calib_required = false;
222 	}
223 }
224 
225 static void tegra_sdhci_set_uhs_signaling(struct sdhci_host *host,
226 					  unsigned timing)
227 {
228 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
229 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
230 
231 	if (timing == MMC_TIMING_UHS_DDR50 ||
232 	    timing == MMC_TIMING_MMC_DDR52)
233 		tegra_host->ddr_signaling = true;
234 
235 	sdhci_set_uhs_signaling(host, timing);
236 }
237 
238 static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap)
239 {
240 	u32 reg;
241 
242 	reg = sdhci_readl(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
243 	reg &= ~SDHCI_CLOCK_CTRL_TAP_MASK;
244 	reg |= tap << SDHCI_CLOCK_CTRL_TAP_SHIFT;
245 	sdhci_writel(host, reg, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
246 }
247 
248 static int tegra_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
249 {
250 	unsigned int min, max;
251 
252 	/*
253 	 * Start search for minimum tap value at 10, as smaller values are
254 	 * may wrongly be reported as working but fail at higher speeds,
255 	 * according to the TRM.
256 	 */
257 	min = 10;
258 	while (min < 255) {
259 		tegra_sdhci_set_tap(host, min);
260 		if (!mmc_send_tuning(host->mmc, opcode, NULL))
261 			break;
262 		min++;
263 	}
264 
265 	/* Find the maximum tap value that still passes. */
266 	max = min + 1;
267 	while (max < 255) {
268 		tegra_sdhci_set_tap(host, max);
269 		if (mmc_send_tuning(host->mmc, opcode, NULL)) {
270 			max--;
271 			break;
272 		}
273 		max++;
274 	}
275 
276 	/* The TRM states the ideal tap value is at 75% in the passing range. */
277 	tegra_sdhci_set_tap(host, min + ((max - min) * 3 / 4));
278 
279 	return mmc_send_tuning(host->mmc, opcode, NULL);
280 }
281 
282 static void tegra_sdhci_voltage_switch(struct sdhci_host *host)
283 {
284 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
285 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
286 	const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
287 
288 	if (soc_data->nvquirks & NVQUIRK_HAS_PADCALIB)
289 		tegra_host->pad_calib_required = true;
290 }
291 
292 static const struct sdhci_ops tegra_sdhci_ops = {
293 	.get_ro     = tegra_sdhci_get_ro,
294 	.read_w     = tegra_sdhci_readw,
295 	.write_l    = tegra_sdhci_writel,
296 	.set_clock  = tegra_sdhci_set_clock,
297 	.set_bus_width = sdhci_set_bus_width,
298 	.reset      = tegra_sdhci_reset,
299 	.platform_execute_tuning = tegra_sdhci_execute_tuning,
300 	.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
301 	.voltage_switch = tegra_sdhci_voltage_switch,
302 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
303 };
304 
305 static const struct sdhci_pltfm_data sdhci_tegra20_pdata = {
306 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
307 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
308 		  SDHCI_QUIRK_NO_HISPD_BIT |
309 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
310 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
311 	.ops  = &tegra_sdhci_ops,
312 };
313 
314 static const struct sdhci_tegra_soc_data soc_data_tegra20 = {
315 	.pdata = &sdhci_tegra20_pdata,
316 	.nvquirks = NVQUIRK_FORCE_SDHCI_SPEC_200 |
317 		    NVQUIRK_ENABLE_BLOCK_GAP_DET,
318 };
319 
320 static const struct sdhci_pltfm_data sdhci_tegra30_pdata = {
321 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
322 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
323 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
324 		  SDHCI_QUIRK_NO_HISPD_BIT |
325 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
326 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
327 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
328 		   SDHCI_QUIRK2_BROKEN_HS200 |
329 		   /*
330 		    * Auto-CMD23 leads to "Got command interrupt 0x00010000 even
331 		    * though no command operation was in progress."
332 		    *
333 		    * The exact reason is unknown, as the same hardware seems
334 		    * to support Auto CMD23 on a downstream 3.1 kernel.
335 		    */
336 		   SDHCI_QUIRK2_ACMD23_BROKEN,
337 	.ops  = &tegra_sdhci_ops,
338 };
339 
340 static const struct sdhci_tegra_soc_data soc_data_tegra30 = {
341 	.pdata = &sdhci_tegra30_pdata,
342 	.nvquirks = NVQUIRK_ENABLE_SDHCI_SPEC_300 |
343 		    NVQUIRK_ENABLE_SDR50 |
344 		    NVQUIRK_ENABLE_SDR104 |
345 		    NVQUIRK_HAS_PADCALIB,
346 };
347 
348 static const struct sdhci_ops tegra114_sdhci_ops = {
349 	.get_ro     = tegra_sdhci_get_ro,
350 	.read_w     = tegra_sdhci_readw,
351 	.write_w    = tegra_sdhci_writew,
352 	.write_l    = tegra_sdhci_writel,
353 	.set_clock  = tegra_sdhci_set_clock,
354 	.set_bus_width = sdhci_set_bus_width,
355 	.reset      = tegra_sdhci_reset,
356 	.platform_execute_tuning = tegra_sdhci_execute_tuning,
357 	.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
358 	.voltage_switch = tegra_sdhci_voltage_switch,
359 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
360 };
361 
362 static const struct sdhci_pltfm_data sdhci_tegra114_pdata = {
363 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
364 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
365 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
366 		  SDHCI_QUIRK_NO_HISPD_BIT |
367 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
368 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
369 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
370 	.ops  = &tegra114_sdhci_ops,
371 };
372 
373 static const struct sdhci_tegra_soc_data soc_data_tegra114 = {
374 	.pdata = &sdhci_tegra114_pdata,
375 };
376 
377 static const struct sdhci_pltfm_data sdhci_tegra124_pdata = {
378 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
379 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
380 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
381 		  SDHCI_QUIRK_NO_HISPD_BIT |
382 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
383 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
384 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
385 		   /*
386 		    * The TRM states that the SD/MMC controller found on
387 		    * Tegra124 can address 34 bits (the maximum supported by
388 		    * the Tegra memory controller), but tests show that DMA
389 		    * to or from above 4 GiB doesn't work. This is possibly
390 		    * caused by missing programming, though it's not obvious
391 		    * what sequence is required. Mark 64-bit DMA broken for
392 		    * now to fix this for existing users (e.g. Nyan boards).
393 		    */
394 		   SDHCI_QUIRK2_BROKEN_64_BIT_DMA,
395 	.ops  = &tegra114_sdhci_ops,
396 };
397 
398 static const struct sdhci_tegra_soc_data soc_data_tegra124 = {
399 	.pdata = &sdhci_tegra124_pdata,
400 };
401 
402 static const struct sdhci_pltfm_data sdhci_tegra210_pdata = {
403 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
404 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
405 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
406 		  SDHCI_QUIRK_NO_HISPD_BIT |
407 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
408 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
409 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
410 	.ops  = &tegra114_sdhci_ops,
411 };
412 
413 static const struct sdhci_tegra_soc_data soc_data_tegra210 = {
414 	.pdata = &sdhci_tegra210_pdata,
415 };
416 
417 static const struct sdhci_pltfm_data sdhci_tegra186_pdata = {
418 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
419 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
420 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
421 		  SDHCI_QUIRK_NO_HISPD_BIT |
422 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
423 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
424 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
425 		   /* SDHCI controllers on Tegra186 support 40-bit addressing.
426 		    * IOVA addresses are 48-bit wide on Tegra186.
427 		    * With 64-bit dma mask used for SDHCI, accesses can
428 		    * be broken. Disable 64-bit dma, which would fall back
429 		    * to 32-bit dma mask. Ideally 40-bit dma mask would work,
430 		    * But it is not supported as of now.
431 		    */
432 		   SDHCI_QUIRK2_BROKEN_64_BIT_DMA,
433 	.ops  = &tegra114_sdhci_ops,
434 };
435 
436 static const struct sdhci_tegra_soc_data soc_data_tegra186 = {
437 	.pdata = &sdhci_tegra186_pdata,
438 };
439 
440 static const struct of_device_id sdhci_tegra_dt_match[] = {
441 	{ .compatible = "nvidia,tegra186-sdhci", .data = &soc_data_tegra186 },
442 	{ .compatible = "nvidia,tegra210-sdhci", .data = &soc_data_tegra210 },
443 	{ .compatible = "nvidia,tegra124-sdhci", .data = &soc_data_tegra124 },
444 	{ .compatible = "nvidia,tegra114-sdhci", .data = &soc_data_tegra114 },
445 	{ .compatible = "nvidia,tegra30-sdhci", .data = &soc_data_tegra30 },
446 	{ .compatible = "nvidia,tegra20-sdhci", .data = &soc_data_tegra20 },
447 	{}
448 };
449 MODULE_DEVICE_TABLE(of, sdhci_tegra_dt_match);
450 
451 static int sdhci_tegra_probe(struct platform_device *pdev)
452 {
453 	const struct of_device_id *match;
454 	const struct sdhci_tegra_soc_data *soc_data;
455 	struct sdhci_host *host;
456 	struct sdhci_pltfm_host *pltfm_host;
457 	struct sdhci_tegra *tegra_host;
458 	struct clk *clk;
459 	int rc;
460 
461 	match = of_match_device(sdhci_tegra_dt_match, &pdev->dev);
462 	if (!match)
463 		return -EINVAL;
464 	soc_data = match->data;
465 
466 	host = sdhci_pltfm_init(pdev, soc_data->pdata, sizeof(*tegra_host));
467 	if (IS_ERR(host))
468 		return PTR_ERR(host);
469 	pltfm_host = sdhci_priv(host);
470 
471 	tegra_host = sdhci_pltfm_priv(pltfm_host);
472 	tegra_host->ddr_signaling = false;
473 	tegra_host->pad_calib_required = false;
474 	tegra_host->soc_data = soc_data;
475 
476 	rc = mmc_of_parse(host->mmc);
477 	if (rc)
478 		goto err_parse_dt;
479 
480 	if (tegra_host->soc_data->nvquirks & NVQUIRK_ENABLE_DDR50)
481 		host->mmc->caps |= MMC_CAP_1_8V_DDR;
482 
483 	tegra_host->power_gpio = devm_gpiod_get_optional(&pdev->dev, "power",
484 							 GPIOD_OUT_HIGH);
485 	if (IS_ERR(tegra_host->power_gpio)) {
486 		rc = PTR_ERR(tegra_host->power_gpio);
487 		goto err_power_req;
488 	}
489 
490 	clk = devm_clk_get(mmc_dev(host->mmc), NULL);
491 	if (IS_ERR(clk)) {
492 		dev_err(mmc_dev(host->mmc), "clk err\n");
493 		rc = PTR_ERR(clk);
494 		goto err_clk_get;
495 	}
496 	clk_prepare_enable(clk);
497 	pltfm_host->clk = clk;
498 
499 	tegra_host->rst = devm_reset_control_get_exclusive(&pdev->dev,
500 							   "sdhci");
501 	if (IS_ERR(tegra_host->rst)) {
502 		rc = PTR_ERR(tegra_host->rst);
503 		dev_err(&pdev->dev, "failed to get reset control: %d\n", rc);
504 		goto err_rst_get;
505 	}
506 
507 	rc = reset_control_assert(tegra_host->rst);
508 	if (rc)
509 		goto err_rst_get;
510 
511 	usleep_range(2000, 4000);
512 
513 	rc = reset_control_deassert(tegra_host->rst);
514 	if (rc)
515 		goto err_rst_get;
516 
517 	usleep_range(2000, 4000);
518 
519 	rc = sdhci_add_host(host);
520 	if (rc)
521 		goto err_add_host;
522 
523 	return 0;
524 
525 err_add_host:
526 	reset_control_assert(tegra_host->rst);
527 err_rst_get:
528 	clk_disable_unprepare(pltfm_host->clk);
529 err_clk_get:
530 err_power_req:
531 err_parse_dt:
532 	sdhci_pltfm_free(pdev);
533 	return rc;
534 }
535 
536 static int sdhci_tegra_remove(struct platform_device *pdev)
537 {
538 	struct sdhci_host *host = platform_get_drvdata(pdev);
539 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
540 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
541 
542 	sdhci_remove_host(host, 0);
543 
544 	reset_control_assert(tegra_host->rst);
545 	usleep_range(2000, 4000);
546 	clk_disable_unprepare(pltfm_host->clk);
547 
548 	sdhci_pltfm_free(pdev);
549 
550 	return 0;
551 }
552 
553 static struct platform_driver sdhci_tegra_driver = {
554 	.driver		= {
555 		.name	= "sdhci-tegra",
556 		.of_match_table = sdhci_tegra_dt_match,
557 		.pm	= &sdhci_pltfm_pmops,
558 	},
559 	.probe		= sdhci_tegra_probe,
560 	.remove		= sdhci_tegra_remove,
561 };
562 
563 module_platform_driver(sdhci_tegra_driver);
564 
565 MODULE_DESCRIPTION("SDHCI driver for Tegra");
566 MODULE_AUTHOR("Google, Inc.");
567 MODULE_LICENSE("GPL v2");
568