xref: /openbmc/linux/drivers/mmc/host/sdhci-st.c (revision c4c3c32d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Support for SDHCI on STMicroelectronics SoCs
4  *
5  * Copyright (C) 2014 STMicroelectronics Ltd
6  * Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
7  * Contributors: Peter Griffin <peter.griffin@linaro.org>
8  *
9  * Based on sdhci-cns3xxx.c
10  */
11 
12 #include <linux/io.h>
13 #include <linux/of.h>
14 #include <linux/module.h>
15 #include <linux/err.h>
16 #include <linux/mmc/host.h>
17 #include <linux/reset.h>
18 #include "sdhci-pltfm.h"
19 
20 struct st_mmc_platform_data {
21 	struct  reset_control *rstc;
22 	struct  clk *icnclk;
23 	void __iomem *top_ioaddr;
24 };
25 
26 /* MMCSS glue logic to setup the HC on some ST SoCs (e.g. STiH407 family) */
27 
28 #define ST_MMC_CCONFIG_REG_1		0x400
29 #define ST_MMC_CCONFIG_TIMEOUT_CLK_UNIT	BIT(24)
30 #define ST_MMC_CCONFIG_TIMEOUT_CLK_FREQ	BIT(12)
31 #define ST_MMC_CCONFIG_TUNING_COUNT_DEFAULT	BIT(8)
32 #define ST_MMC_CCONFIG_ASYNC_WAKEUP	BIT(0)
33 #define ST_MMC_CCONFIG_1_DEFAULT	\
34 				((ST_MMC_CCONFIG_TIMEOUT_CLK_UNIT) | \
35 				 (ST_MMC_CCONFIG_TIMEOUT_CLK_FREQ) | \
36 				 (ST_MMC_CCONFIG_TUNING_COUNT_DEFAULT))
37 
38 #define ST_MMC_CCONFIG_REG_2		0x404
39 #define ST_MMC_CCONFIG_HIGH_SPEED	BIT(28)
40 #define ST_MMC_CCONFIG_ADMA2		BIT(24)
41 #define ST_MMC_CCONFIG_8BIT		BIT(20)
42 #define ST_MMC_CCONFIG_MAX_BLK_LEN	16
43 #define  MAX_BLK_LEN_1024		1
44 #define  MAX_BLK_LEN_2048		2
45 #define BASE_CLK_FREQ_200		0xc8
46 #define BASE_CLK_FREQ_100		0x64
47 #define BASE_CLK_FREQ_50		0x32
48 #define ST_MMC_CCONFIG_2_DEFAULT \
49 	(ST_MMC_CCONFIG_HIGH_SPEED | ST_MMC_CCONFIG_ADMA2 | \
50 	 ST_MMC_CCONFIG_8BIT | \
51 	 (MAX_BLK_LEN_1024 << ST_MMC_CCONFIG_MAX_BLK_LEN))
52 
53 #define ST_MMC_CCONFIG_REG_3			0x408
54 #define ST_MMC_CCONFIG_EMMC_SLOT_TYPE		BIT(28)
55 #define ST_MMC_CCONFIG_64BIT			BIT(24)
56 #define ST_MMC_CCONFIG_ASYNCH_INTR_SUPPORT	BIT(20)
57 #define ST_MMC_CCONFIG_1P8_VOLT			BIT(16)
58 #define ST_MMC_CCONFIG_3P0_VOLT			BIT(12)
59 #define ST_MMC_CCONFIG_3P3_VOLT			BIT(8)
60 #define ST_MMC_CCONFIG_SUSP_RES_SUPPORT		BIT(4)
61 #define ST_MMC_CCONFIG_SDMA			BIT(0)
62 #define ST_MMC_CCONFIG_3_DEFAULT	\
63 			 (ST_MMC_CCONFIG_ASYNCH_INTR_SUPPORT	| \
64 			  ST_MMC_CCONFIG_3P3_VOLT		| \
65 			  ST_MMC_CCONFIG_SUSP_RES_SUPPORT	| \
66 			  ST_MMC_CCONFIG_SDMA)
67 
68 #define ST_MMC_CCONFIG_REG_4	0x40c
69 #define ST_MMC_CCONFIG_D_DRIVER	BIT(20)
70 #define ST_MMC_CCONFIG_C_DRIVER	BIT(16)
71 #define ST_MMC_CCONFIG_A_DRIVER	BIT(12)
72 #define ST_MMC_CCONFIG_DDR50	BIT(8)
73 #define ST_MMC_CCONFIG_SDR104	BIT(4)
74 #define ST_MMC_CCONFIG_SDR50	BIT(0)
75 #define ST_MMC_CCONFIG_4_DEFAULT	0
76 
77 #define ST_MMC_CCONFIG_REG_5		0x410
78 #define ST_MMC_CCONFIG_TUNING_FOR_SDR50	BIT(8)
79 #define RETUNING_TIMER_CNT_MAX		0xf
80 #define ST_MMC_CCONFIG_5_DEFAULT	0
81 
82 /* I/O configuration for Arasan IP */
83 #define ST_MMC_GP_OUTPUT	0x450
84 #define ST_MMC_GP_OUTPUT_CD	BIT(12)
85 
86 #define ST_MMC_STATUS_R		0x460
87 
88 #define ST_TOP_MMC_DLY_FIX_OFF(x)	(x - 0x8)
89 
90 /* TOP config registers to manage static and dynamic delay */
91 #define ST_TOP_MMC_TX_CLK_DLY			ST_TOP_MMC_DLY_FIX_OFF(0x8)
92 #define ST_TOP_MMC_RX_CLK_DLY			ST_TOP_MMC_DLY_FIX_OFF(0xc)
93 /* MMC delay control register */
94 #define ST_TOP_MMC_DLY_CTRL			ST_TOP_MMC_DLY_FIX_OFF(0x18)
95 #define ST_TOP_MMC_DLY_CTRL_DLL_BYPASS_CMD	BIT(0)
96 #define ST_TOP_MMC_DLY_CTRL_DLL_BYPASS_PH_SEL	BIT(1)
97 #define ST_TOP_MMC_DLY_CTRL_TX_DLL_ENABLE	BIT(8)
98 #define ST_TOP_MMC_DLY_CTRL_RX_DLL_ENABLE	BIT(9)
99 #define ST_TOP_MMC_DLY_CTRL_ATUNE_NOT_CFG_DLY	BIT(10)
100 #define ST_TOP_MMC_START_DLL_LOCK		BIT(11)
101 
102 /* register to provide the phase-shift value for DLL */
103 #define ST_TOP_MMC_TX_DLL_STEP_DLY		ST_TOP_MMC_DLY_FIX_OFF(0x1c)
104 #define ST_TOP_MMC_RX_DLL_STEP_DLY		ST_TOP_MMC_DLY_FIX_OFF(0x20)
105 #define ST_TOP_MMC_RX_CMD_STEP_DLY		ST_TOP_MMC_DLY_FIX_OFF(0x24)
106 
107 /* phase shift delay on the tx clk 2.188ns */
108 #define ST_TOP_MMC_TX_DLL_STEP_DLY_VALID	0x6
109 
110 #define ST_TOP_MMC_DLY_MAX			0xf
111 
112 #define ST_TOP_MMC_DYN_DLY_CONF	\
113 		(ST_TOP_MMC_DLY_CTRL_TX_DLL_ENABLE | \
114 		 ST_TOP_MMC_DLY_CTRL_ATUNE_NOT_CFG_DLY | \
115 		 ST_TOP_MMC_START_DLL_LOCK)
116 
117 /*
118  * For clock speeds greater than 90MHz, we need to check that the
119  * DLL procedure has finished before switching to ultra-speed modes.
120  */
121 #define	CLK_TO_CHECK_DLL_LOCK	90000000
122 
123 static inline void st_mmcss_set_static_delay(void __iomem *ioaddr)
124 {
125 	if (!ioaddr)
126 		return;
127 
128 	writel_relaxed(0x0, ioaddr + ST_TOP_MMC_DLY_CTRL);
129 	writel_relaxed(ST_TOP_MMC_DLY_MAX,
130 			ioaddr + ST_TOP_MMC_TX_CLK_DLY);
131 }
132 
133 /**
134  * st_mmcss_cconfig: configure the Arasan HC inside the flashSS.
135  * @np: dt device node.
136  * @host: sdhci host
137  * Description: this function is to configure the Arasan host controller.
138  * On some ST SoCs, i.e. STiH407 family, the MMC devices inside a dedicated
139  * flashSS sub-system which needs to be configured to be compliant to eMMC 4.5
140  * or eMMC4.3.  This has to be done before registering the sdhci host.
141  */
142 static void st_mmcss_cconfig(struct device_node *np, struct sdhci_host *host)
143 {
144 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
145 	struct mmc_host *mhost = host->mmc;
146 	u32 cconf2, cconf3, cconf4, cconf5;
147 
148 	if (!of_device_is_compatible(np, "st,sdhci-stih407"))
149 		return;
150 
151 	cconf2 = ST_MMC_CCONFIG_2_DEFAULT;
152 	cconf3 = ST_MMC_CCONFIG_3_DEFAULT;
153 	cconf4 = ST_MMC_CCONFIG_4_DEFAULT;
154 	cconf5 = ST_MMC_CCONFIG_5_DEFAULT;
155 
156 	writel_relaxed(ST_MMC_CCONFIG_1_DEFAULT,
157 			host->ioaddr + ST_MMC_CCONFIG_REG_1);
158 
159 	/* Set clock frequency, default to 50MHz if max-frequency is not
160 	 * provided */
161 
162 	switch (mhost->f_max) {
163 	case 200000000:
164 		clk_set_rate(pltfm_host->clk, mhost->f_max);
165 		cconf2 |= BASE_CLK_FREQ_200;
166 		break;
167 	case 100000000:
168 		clk_set_rate(pltfm_host->clk, mhost->f_max);
169 		cconf2 |= BASE_CLK_FREQ_100;
170 		break;
171 	default:
172 		clk_set_rate(pltfm_host->clk, 50000000);
173 		cconf2 |= BASE_CLK_FREQ_50;
174 	}
175 
176 	writel_relaxed(cconf2, host->ioaddr + ST_MMC_CCONFIG_REG_2);
177 
178 	if (!mmc_card_is_removable(mhost))
179 		cconf3 |= ST_MMC_CCONFIG_EMMC_SLOT_TYPE;
180 	else
181 		/* CARD _D ET_CTRL */
182 		writel_relaxed(ST_MMC_GP_OUTPUT_CD,
183 				host->ioaddr + ST_MMC_GP_OUTPUT);
184 
185 	if (mhost->caps & MMC_CAP_UHS_SDR50) {
186 		/* use 1.8V */
187 		cconf3 |= ST_MMC_CCONFIG_1P8_VOLT;
188 		cconf4 |= ST_MMC_CCONFIG_SDR50;
189 		/* Use tuning */
190 		cconf5 |= ST_MMC_CCONFIG_TUNING_FOR_SDR50;
191 		/* Max timeout for retuning */
192 		cconf5 |= RETUNING_TIMER_CNT_MAX;
193 	}
194 
195 	if (mhost->caps & MMC_CAP_UHS_SDR104) {
196 		/*
197 		 * SDR104 implies the HC can support HS200 mode, so
198 		 * it's mandatory to use 1.8V
199 		 */
200 		cconf3 |= ST_MMC_CCONFIG_1P8_VOLT;
201 		cconf4 |= ST_MMC_CCONFIG_SDR104;
202 		/* Max timeout for retuning */
203 		cconf5 |= RETUNING_TIMER_CNT_MAX;
204 	}
205 
206 	if (mhost->caps & MMC_CAP_UHS_DDR50)
207 		cconf4 |= ST_MMC_CCONFIG_DDR50;
208 
209 	writel_relaxed(cconf3, host->ioaddr + ST_MMC_CCONFIG_REG_3);
210 	writel_relaxed(cconf4, host->ioaddr + ST_MMC_CCONFIG_REG_4);
211 	writel_relaxed(cconf5, host->ioaddr + ST_MMC_CCONFIG_REG_5);
212 }
213 
214 static inline void st_mmcss_set_dll(void __iomem *ioaddr)
215 {
216 	if (!ioaddr)
217 		return;
218 
219 	writel_relaxed(ST_TOP_MMC_DYN_DLY_CONF,	ioaddr + ST_TOP_MMC_DLY_CTRL);
220 	writel_relaxed(ST_TOP_MMC_TX_DLL_STEP_DLY_VALID,
221 			ioaddr + ST_TOP_MMC_TX_DLL_STEP_DLY);
222 }
223 
224 static int st_mmcss_lock_dll(void __iomem *ioaddr)
225 {
226 	unsigned long curr, value;
227 	unsigned long finish = jiffies + HZ;
228 
229 	/* Checks if the DLL procedure is finished */
230 	do {
231 		curr = jiffies;
232 		value = readl(ioaddr + ST_MMC_STATUS_R);
233 		if (value & 0x1)
234 			return 0;
235 
236 		cpu_relax();
237 	} while (!time_after_eq(curr, finish));
238 
239 	return -EBUSY;
240 }
241 
242 static int sdhci_st_set_dll_for_clock(struct sdhci_host *host)
243 {
244 	int ret = 0;
245 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
246 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
247 
248 	if (host->clock > CLK_TO_CHECK_DLL_LOCK) {
249 		st_mmcss_set_dll(pdata->top_ioaddr);
250 		ret = st_mmcss_lock_dll(host->ioaddr);
251 	}
252 
253 	return ret;
254 }
255 
256 static void sdhci_st_set_uhs_signaling(struct sdhci_host *host,
257 					unsigned int uhs)
258 {
259 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
260 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
261 	u16 ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
262 	int ret = 0;
263 
264 	/* Select Bus Speed Mode for host */
265 	ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
266 	switch (uhs) {
267 	/*
268 	 * Set V18_EN -- UHS modes do not work without this.
269 	 * does not change signaling voltage
270 	 */
271 
272 	case MMC_TIMING_UHS_SDR12:
273 		st_mmcss_set_static_delay(pdata->top_ioaddr);
274 		ctrl_2 |= SDHCI_CTRL_UHS_SDR12 | SDHCI_CTRL_VDD_180;
275 		break;
276 	case MMC_TIMING_UHS_SDR25:
277 		st_mmcss_set_static_delay(pdata->top_ioaddr);
278 		ctrl_2 |= SDHCI_CTRL_UHS_SDR25 | SDHCI_CTRL_VDD_180;
279 		break;
280 	case MMC_TIMING_UHS_SDR50:
281 		st_mmcss_set_static_delay(pdata->top_ioaddr);
282 		ctrl_2 |= SDHCI_CTRL_UHS_SDR50 | SDHCI_CTRL_VDD_180;
283 		ret = sdhci_st_set_dll_for_clock(host);
284 		break;
285 	case MMC_TIMING_UHS_SDR104:
286 	case MMC_TIMING_MMC_HS200:
287 		st_mmcss_set_static_delay(pdata->top_ioaddr);
288 		ctrl_2 |= SDHCI_CTRL_UHS_SDR104 | SDHCI_CTRL_VDD_180;
289 		ret =  sdhci_st_set_dll_for_clock(host);
290 		break;
291 	case MMC_TIMING_UHS_DDR50:
292 	case MMC_TIMING_MMC_DDR52:
293 		st_mmcss_set_static_delay(pdata->top_ioaddr);
294 		ctrl_2 |= SDHCI_CTRL_UHS_DDR50 | SDHCI_CTRL_VDD_180;
295 		break;
296 	}
297 
298 	if (ret)
299 		dev_warn(mmc_dev(host->mmc), "Error setting dll for clock "
300 						"(uhs %d)\n", uhs);
301 
302 	dev_dbg(mmc_dev(host->mmc), "uhs %d, ctrl_2 %04X\n", uhs, ctrl_2);
303 
304 	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
305 }
306 
307 static u32 sdhci_st_readl(struct sdhci_host *host, int reg)
308 {
309 	u32 ret;
310 
311 	switch (reg) {
312 	case SDHCI_CAPABILITIES:
313 		ret = readl_relaxed(host->ioaddr + reg);
314 		/* Support 3.3V and 1.8V */
315 		ret &= ~SDHCI_CAN_VDD_300;
316 		break;
317 	default:
318 		ret = readl_relaxed(host->ioaddr + reg);
319 	}
320 	return ret;
321 }
322 
323 static const struct sdhci_ops sdhci_st_ops = {
324 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
325 	.set_clock = sdhci_set_clock,
326 	.set_bus_width = sdhci_set_bus_width,
327 	.read_l = sdhci_st_readl,
328 	.reset = sdhci_reset,
329 	.set_uhs_signaling = sdhci_st_set_uhs_signaling,
330 };
331 
332 static const struct sdhci_pltfm_data sdhci_st_pdata = {
333 	.ops = &sdhci_st_ops,
334 	.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
335 		SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
336 		SDHCI_QUIRK_NO_HISPD_BIT,
337 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
338 		SDHCI_QUIRK2_STOP_WITH_TC,
339 };
340 
341 
342 static int sdhci_st_probe(struct platform_device *pdev)
343 {
344 	struct device_node *np = pdev->dev.of_node;
345 	struct sdhci_host *host;
346 	struct st_mmc_platform_data *pdata;
347 	struct sdhci_pltfm_host *pltfm_host;
348 	struct clk *clk, *icnclk;
349 	int ret = 0;
350 	u16 host_version;
351 	struct resource *res;
352 	struct reset_control *rstc;
353 
354 	clk =  devm_clk_get(&pdev->dev, "mmc");
355 	if (IS_ERR(clk)) {
356 		dev_err(&pdev->dev, "Peripheral clk not found\n");
357 		return PTR_ERR(clk);
358 	}
359 
360 	/* ICN clock isn't compulsory, but use it if it's provided. */
361 	icnclk = devm_clk_get(&pdev->dev, "icn");
362 	if (IS_ERR(icnclk))
363 		icnclk = NULL;
364 
365 	rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
366 	if (IS_ERR(rstc))
367 		return PTR_ERR(rstc);
368 	reset_control_deassert(rstc);
369 
370 	host = sdhci_pltfm_init(pdev, &sdhci_st_pdata, sizeof(*pdata));
371 	if (IS_ERR(host)) {
372 		dev_err(&pdev->dev, "Failed sdhci_pltfm_init\n");
373 		ret = PTR_ERR(host);
374 		goto err_pltfm_init;
375 	}
376 
377 	pltfm_host = sdhci_priv(host);
378 	pdata = sdhci_pltfm_priv(pltfm_host);
379 	pdata->rstc = rstc;
380 
381 	ret = mmc_of_parse(host->mmc);
382 	if (ret) {
383 		dev_err(&pdev->dev, "Failed mmc_of_parse\n");
384 		goto err_of;
385 	}
386 
387 	ret = clk_prepare_enable(clk);
388 	if (ret) {
389 		dev_err(&pdev->dev, "Failed to prepare clock\n");
390 		goto err_of;
391 	}
392 
393 	ret = clk_prepare_enable(icnclk);
394 	if (ret) {
395 		dev_err(&pdev->dev, "Failed to prepare icn clock\n");
396 		goto err_icnclk;
397 	}
398 
399 	/* Configure the FlashSS Top registers for setting eMMC TX/RX delay */
400 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
401 					   "top-mmc-delay");
402 	pdata->top_ioaddr = devm_ioremap_resource(&pdev->dev, res);
403 	if (IS_ERR(pdata->top_ioaddr))
404 		pdata->top_ioaddr = NULL;
405 
406 	pltfm_host->clk = clk;
407 	pdata->icnclk = icnclk;
408 
409 	/* Configure the Arasan HC inside the flashSS */
410 	st_mmcss_cconfig(np, host);
411 
412 	ret = sdhci_add_host(host);
413 	if (ret)
414 		goto err_out;
415 
416 	host_version = readw_relaxed((host->ioaddr + SDHCI_HOST_VERSION));
417 
418 	dev_info(&pdev->dev, "SDHCI ST Initialised: Host Version: 0x%x Vendor Version 0x%x\n",
419 		((host_version & SDHCI_SPEC_VER_MASK) >> SDHCI_SPEC_VER_SHIFT),
420 		((host_version & SDHCI_VENDOR_VER_MASK) >>
421 		SDHCI_VENDOR_VER_SHIFT));
422 
423 	return 0;
424 
425 err_out:
426 	clk_disable_unprepare(icnclk);
427 err_icnclk:
428 	clk_disable_unprepare(clk);
429 err_of:
430 	sdhci_pltfm_free(pdev);
431 err_pltfm_init:
432 	reset_control_assert(rstc);
433 
434 	return ret;
435 }
436 
437 static int sdhci_st_remove(struct platform_device *pdev)
438 {
439 	struct sdhci_host *host = platform_get_drvdata(pdev);
440 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
441 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
442 	struct reset_control *rstc = pdata->rstc;
443 
444 	sdhci_pltfm_unregister(pdev);
445 
446 	clk_disable_unprepare(pdata->icnclk);
447 
448 	reset_control_assert(rstc);
449 
450 	return 0;
451 }
452 
453 #ifdef CONFIG_PM_SLEEP
454 static int sdhci_st_suspend(struct device *dev)
455 {
456 	struct sdhci_host *host = dev_get_drvdata(dev);
457 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
458 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
459 	int ret;
460 
461 	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
462 		mmc_retune_needed(host->mmc);
463 
464 	ret = sdhci_suspend_host(host);
465 	if (ret)
466 		goto out;
467 
468 	reset_control_assert(pdata->rstc);
469 
470 	clk_disable_unprepare(pdata->icnclk);
471 	clk_disable_unprepare(pltfm_host->clk);
472 out:
473 	return ret;
474 }
475 
476 static int sdhci_st_resume(struct device *dev)
477 {
478 	struct sdhci_host *host = dev_get_drvdata(dev);
479 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
480 	struct st_mmc_platform_data *pdata = sdhci_pltfm_priv(pltfm_host);
481 	struct device_node *np = dev->of_node;
482 	int ret;
483 
484 	ret = clk_prepare_enable(pltfm_host->clk);
485 	if (ret)
486 		return ret;
487 
488 	ret = clk_prepare_enable(pdata->icnclk);
489 	if (ret) {
490 		clk_disable_unprepare(pltfm_host->clk);
491 		return ret;
492 	}
493 
494 	reset_control_deassert(pdata->rstc);
495 
496 	st_mmcss_cconfig(np, host);
497 
498 	return sdhci_resume_host(host);
499 }
500 #endif
501 
502 static SIMPLE_DEV_PM_OPS(sdhci_st_pmops, sdhci_st_suspend, sdhci_st_resume);
503 
504 static const struct of_device_id st_sdhci_match[] = {
505 	{ .compatible = "st,sdhci" },
506 	{},
507 };
508 
509 MODULE_DEVICE_TABLE(of, st_sdhci_match);
510 
511 static struct platform_driver sdhci_st_driver = {
512 	.probe = sdhci_st_probe,
513 	.remove = sdhci_st_remove,
514 	.driver = {
515 		   .name = "sdhci-st",
516 		   .probe_type = PROBE_PREFER_ASYNCHRONOUS,
517 		   .pm = &sdhci_st_pmops,
518 		   .of_match_table = st_sdhci_match,
519 		  },
520 };
521 
522 module_platform_driver(sdhci_st_driver);
523 
524 MODULE_DESCRIPTION("SDHCI driver for STMicroelectronics SoCs");
525 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");
526 MODULE_LICENSE("GPL v2");
527 MODULE_ALIAS("platform:sdhci-st");
528