xref: /openbmc/linux/drivers/mmc/host/sdhci-tegra.c (revision f220d3eb)
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 	/*
214 	 * In DDR50/52 modes the Tegra SDHCI controllers require the SDHCI
215 	 * divider to be configured to divided the host clock by two. The SDHCI
216 	 * clock divider is calculated as part of sdhci_set_clock() by
217 	 * sdhci_calc_clk(). The divider is calculated from host->max_clk and
218 	 * the requested clock rate.
219 	 *
220 	 * By setting the host->max_clk to clock * 2 the divider calculation
221 	 * will always result in the correct value for DDR50/52 modes,
222 	 * regardless of clock rate rounding, which may happen if the value
223 	 * from clk_get_rate() is used.
224 	 */
225 	host_clk = tegra_host->ddr_signaling ? clock * 2 : clock;
226 	clk_set_rate(pltfm_host->clk, host_clk);
227 	if (tegra_host->ddr_signaling)
228 		host->max_clk = host_clk;
229 	else
230 		host->max_clk = clk_get_rate(pltfm_host->clk);
231 
232 	sdhci_set_clock(host, clock);
233 
234 	if (tegra_host->pad_calib_required) {
235 		tegra_sdhci_pad_autocalib(host);
236 		tegra_host->pad_calib_required = false;
237 	}
238 }
239 
240 static void tegra_sdhci_set_uhs_signaling(struct sdhci_host *host,
241 					  unsigned timing)
242 {
243 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
244 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
245 
246 	if (timing == MMC_TIMING_UHS_DDR50 ||
247 	    timing == MMC_TIMING_MMC_DDR52)
248 		tegra_host->ddr_signaling = true;
249 
250 	sdhci_set_uhs_signaling(host, timing);
251 }
252 
253 static unsigned int tegra_sdhci_get_max_clock(struct sdhci_host *host)
254 {
255 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
256 
257 	return clk_round_rate(pltfm_host->clk, UINT_MAX);
258 }
259 
260 static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap)
261 {
262 	u32 reg;
263 
264 	reg = sdhci_readl(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
265 	reg &= ~SDHCI_CLOCK_CTRL_TAP_MASK;
266 	reg |= tap << SDHCI_CLOCK_CTRL_TAP_SHIFT;
267 	sdhci_writel(host, reg, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
268 }
269 
270 static int tegra_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
271 {
272 	unsigned int min, max;
273 
274 	/*
275 	 * Start search for minimum tap value at 10, as smaller values are
276 	 * may wrongly be reported as working but fail at higher speeds,
277 	 * according to the TRM.
278 	 */
279 	min = 10;
280 	while (min < 255) {
281 		tegra_sdhci_set_tap(host, min);
282 		if (!mmc_send_tuning(host->mmc, opcode, NULL))
283 			break;
284 		min++;
285 	}
286 
287 	/* Find the maximum tap value that still passes. */
288 	max = min + 1;
289 	while (max < 255) {
290 		tegra_sdhci_set_tap(host, max);
291 		if (mmc_send_tuning(host->mmc, opcode, NULL)) {
292 			max--;
293 			break;
294 		}
295 		max++;
296 	}
297 
298 	/* The TRM states the ideal tap value is at 75% in the passing range. */
299 	tegra_sdhci_set_tap(host, min + ((max - min) * 3 / 4));
300 
301 	return mmc_send_tuning(host->mmc, opcode, NULL);
302 }
303 
304 static void tegra_sdhci_voltage_switch(struct sdhci_host *host)
305 {
306 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
307 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
308 	const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
309 
310 	if (soc_data->nvquirks & NVQUIRK_HAS_PADCALIB)
311 		tegra_host->pad_calib_required = true;
312 }
313 
314 static const struct sdhci_ops tegra_sdhci_ops = {
315 	.get_ro     = tegra_sdhci_get_ro,
316 	.read_w     = tegra_sdhci_readw,
317 	.write_l    = tegra_sdhci_writel,
318 	.set_clock  = tegra_sdhci_set_clock,
319 	.set_bus_width = sdhci_set_bus_width,
320 	.reset      = tegra_sdhci_reset,
321 	.platform_execute_tuning = tegra_sdhci_execute_tuning,
322 	.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
323 	.voltage_switch = tegra_sdhci_voltage_switch,
324 	.get_max_clock = tegra_sdhci_get_max_clock,
325 };
326 
327 static const struct sdhci_pltfm_data sdhci_tegra20_pdata = {
328 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
329 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
330 		  SDHCI_QUIRK_NO_HISPD_BIT |
331 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
332 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
333 	.ops  = &tegra_sdhci_ops,
334 };
335 
336 static const struct sdhci_tegra_soc_data soc_data_tegra20 = {
337 	.pdata = &sdhci_tegra20_pdata,
338 	.nvquirks = NVQUIRK_FORCE_SDHCI_SPEC_200 |
339 		    NVQUIRK_ENABLE_BLOCK_GAP_DET,
340 };
341 
342 static const struct sdhci_pltfm_data sdhci_tegra30_pdata = {
343 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
344 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
345 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
346 		  SDHCI_QUIRK_NO_HISPD_BIT |
347 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
348 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
349 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
350 		   SDHCI_QUIRK2_BROKEN_HS200 |
351 		   /*
352 		    * Auto-CMD23 leads to "Got command interrupt 0x00010000 even
353 		    * though no command operation was in progress."
354 		    *
355 		    * The exact reason is unknown, as the same hardware seems
356 		    * to support Auto CMD23 on a downstream 3.1 kernel.
357 		    */
358 		   SDHCI_QUIRK2_ACMD23_BROKEN,
359 	.ops  = &tegra_sdhci_ops,
360 };
361 
362 static const struct sdhci_tegra_soc_data soc_data_tegra30 = {
363 	.pdata = &sdhci_tegra30_pdata,
364 	.nvquirks = NVQUIRK_ENABLE_SDHCI_SPEC_300 |
365 		    NVQUIRK_ENABLE_SDR50 |
366 		    NVQUIRK_ENABLE_SDR104 |
367 		    NVQUIRK_HAS_PADCALIB,
368 };
369 
370 static const struct sdhci_ops tegra114_sdhci_ops = {
371 	.get_ro     = tegra_sdhci_get_ro,
372 	.read_w     = tegra_sdhci_readw,
373 	.write_w    = tegra_sdhci_writew,
374 	.write_l    = tegra_sdhci_writel,
375 	.set_clock  = tegra_sdhci_set_clock,
376 	.set_bus_width = sdhci_set_bus_width,
377 	.reset      = tegra_sdhci_reset,
378 	.platform_execute_tuning = tegra_sdhci_execute_tuning,
379 	.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
380 	.voltage_switch = tegra_sdhci_voltage_switch,
381 	.get_max_clock = tegra_sdhci_get_max_clock,
382 };
383 
384 static const struct sdhci_pltfm_data sdhci_tegra114_pdata = {
385 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
386 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
387 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
388 		  SDHCI_QUIRK_NO_HISPD_BIT |
389 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
390 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
391 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
392 	.ops  = &tegra114_sdhci_ops,
393 };
394 
395 static const struct sdhci_tegra_soc_data soc_data_tegra114 = {
396 	.pdata = &sdhci_tegra114_pdata,
397 };
398 
399 static const struct sdhci_pltfm_data sdhci_tegra124_pdata = {
400 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
401 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
402 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
403 		  SDHCI_QUIRK_NO_HISPD_BIT |
404 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
405 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
406 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
407 		   /*
408 		    * The TRM states that the SD/MMC controller found on
409 		    * Tegra124 can address 34 bits (the maximum supported by
410 		    * the Tegra memory controller), but tests show that DMA
411 		    * to or from above 4 GiB doesn't work. This is possibly
412 		    * caused by missing programming, though it's not obvious
413 		    * what sequence is required. Mark 64-bit DMA broken for
414 		    * now to fix this for existing users (e.g. Nyan boards).
415 		    */
416 		   SDHCI_QUIRK2_BROKEN_64_BIT_DMA,
417 	.ops  = &tegra114_sdhci_ops,
418 };
419 
420 static const struct sdhci_tegra_soc_data soc_data_tegra124 = {
421 	.pdata = &sdhci_tegra124_pdata,
422 };
423 
424 static const struct sdhci_pltfm_data sdhci_tegra210_pdata = {
425 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
426 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
427 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
428 		  SDHCI_QUIRK_NO_HISPD_BIT |
429 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
430 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
431 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
432 	.ops  = &tegra114_sdhci_ops,
433 };
434 
435 static const struct sdhci_tegra_soc_data soc_data_tegra210 = {
436 	.pdata = &sdhci_tegra210_pdata,
437 };
438 
439 static const struct sdhci_pltfm_data sdhci_tegra186_pdata = {
440 	.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
441 		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
442 		  SDHCI_QUIRK_SINGLE_POWER_WRITE |
443 		  SDHCI_QUIRK_NO_HISPD_BIT |
444 		  SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
445 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
446 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
447 		   /* SDHCI controllers on Tegra186 support 40-bit addressing.
448 		    * IOVA addresses are 48-bit wide on Tegra186.
449 		    * With 64-bit dma mask used for SDHCI, accesses can
450 		    * be broken. Disable 64-bit dma, which would fall back
451 		    * to 32-bit dma mask. Ideally 40-bit dma mask would work,
452 		    * But it is not supported as of now.
453 		    */
454 		   SDHCI_QUIRK2_BROKEN_64_BIT_DMA,
455 	.ops  = &tegra114_sdhci_ops,
456 };
457 
458 static const struct sdhci_tegra_soc_data soc_data_tegra186 = {
459 	.pdata = &sdhci_tegra186_pdata,
460 };
461 
462 static const struct of_device_id sdhci_tegra_dt_match[] = {
463 	{ .compatible = "nvidia,tegra186-sdhci", .data = &soc_data_tegra186 },
464 	{ .compatible = "nvidia,tegra210-sdhci", .data = &soc_data_tegra210 },
465 	{ .compatible = "nvidia,tegra124-sdhci", .data = &soc_data_tegra124 },
466 	{ .compatible = "nvidia,tegra114-sdhci", .data = &soc_data_tegra114 },
467 	{ .compatible = "nvidia,tegra30-sdhci", .data = &soc_data_tegra30 },
468 	{ .compatible = "nvidia,tegra20-sdhci", .data = &soc_data_tegra20 },
469 	{}
470 };
471 MODULE_DEVICE_TABLE(of, sdhci_tegra_dt_match);
472 
473 static int sdhci_tegra_probe(struct platform_device *pdev)
474 {
475 	const struct of_device_id *match;
476 	const struct sdhci_tegra_soc_data *soc_data;
477 	struct sdhci_host *host;
478 	struct sdhci_pltfm_host *pltfm_host;
479 	struct sdhci_tegra *tegra_host;
480 	struct clk *clk;
481 	int rc;
482 
483 	match = of_match_device(sdhci_tegra_dt_match, &pdev->dev);
484 	if (!match)
485 		return -EINVAL;
486 	soc_data = match->data;
487 
488 	host = sdhci_pltfm_init(pdev, soc_data->pdata, sizeof(*tegra_host));
489 	if (IS_ERR(host))
490 		return PTR_ERR(host);
491 	pltfm_host = sdhci_priv(host);
492 
493 	tegra_host = sdhci_pltfm_priv(pltfm_host);
494 	tegra_host->ddr_signaling = false;
495 	tegra_host->pad_calib_required = false;
496 	tegra_host->soc_data = soc_data;
497 
498 	rc = mmc_of_parse(host->mmc);
499 	if (rc)
500 		goto err_parse_dt;
501 
502 	if (tegra_host->soc_data->nvquirks & NVQUIRK_ENABLE_DDR50)
503 		host->mmc->caps |= MMC_CAP_1_8V_DDR;
504 
505 	tegra_host->power_gpio = devm_gpiod_get_optional(&pdev->dev, "power",
506 							 GPIOD_OUT_HIGH);
507 	if (IS_ERR(tegra_host->power_gpio)) {
508 		rc = PTR_ERR(tegra_host->power_gpio);
509 		goto err_power_req;
510 	}
511 
512 	clk = devm_clk_get(mmc_dev(host->mmc), NULL);
513 	if (IS_ERR(clk)) {
514 		dev_err(mmc_dev(host->mmc), "clk err\n");
515 		rc = PTR_ERR(clk);
516 		goto err_clk_get;
517 	}
518 	clk_prepare_enable(clk);
519 	pltfm_host->clk = clk;
520 
521 	tegra_host->rst = devm_reset_control_get_exclusive(&pdev->dev,
522 							   "sdhci");
523 	if (IS_ERR(tegra_host->rst)) {
524 		rc = PTR_ERR(tegra_host->rst);
525 		dev_err(&pdev->dev, "failed to get reset control: %d\n", rc);
526 		goto err_rst_get;
527 	}
528 
529 	rc = reset_control_assert(tegra_host->rst);
530 	if (rc)
531 		goto err_rst_get;
532 
533 	usleep_range(2000, 4000);
534 
535 	rc = reset_control_deassert(tegra_host->rst);
536 	if (rc)
537 		goto err_rst_get;
538 
539 	usleep_range(2000, 4000);
540 
541 	rc = sdhci_add_host(host);
542 	if (rc)
543 		goto err_add_host;
544 
545 	return 0;
546 
547 err_add_host:
548 	reset_control_assert(tegra_host->rst);
549 err_rst_get:
550 	clk_disable_unprepare(pltfm_host->clk);
551 err_clk_get:
552 err_power_req:
553 err_parse_dt:
554 	sdhci_pltfm_free(pdev);
555 	return rc;
556 }
557 
558 static int sdhci_tegra_remove(struct platform_device *pdev)
559 {
560 	struct sdhci_host *host = platform_get_drvdata(pdev);
561 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
562 	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
563 
564 	sdhci_remove_host(host, 0);
565 
566 	reset_control_assert(tegra_host->rst);
567 	usleep_range(2000, 4000);
568 	clk_disable_unprepare(pltfm_host->clk);
569 
570 	sdhci_pltfm_free(pdev);
571 
572 	return 0;
573 }
574 
575 static struct platform_driver sdhci_tegra_driver = {
576 	.driver		= {
577 		.name	= "sdhci-tegra",
578 		.of_match_table = sdhci_tegra_dt_match,
579 		.pm	= &sdhci_pltfm_pmops,
580 	},
581 	.probe		= sdhci_tegra_probe,
582 	.remove		= sdhci_tegra_remove,
583 };
584 
585 module_platform_driver(sdhci_tegra_driver);
586 
587 MODULE_DESCRIPTION("SDHCI driver for Tegra");
588 MODULE_AUTHOR("Google, Inc.");
589 MODULE_LICENSE("GPL v2");
590