xref: /openbmc/linux/drivers/mmc/host/sdhci-xenon.c (revision 711aab1d)
1 /*
2  * Driver for Marvell Xenon SDHC as a platform device
3  *
4  * Copyright (C) 2016 Marvell, All Rights Reserved.
5  *
6  * Author:	Hu Ziji <huziji@marvell.com>
7  * Date:	2016-8-24
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation version 2.
12  *
13  * Inspired by Jisheng Zhang <jszhang@marvell.com>
14  * Special thanks to Video BG4 project team.
15  */
16 
17 #include <linux/delay.h>
18 #include <linux/ktime.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/pm.h>
22 #include <linux/pm_runtime.h>
23 
24 #include "sdhci-pltfm.h"
25 #include "sdhci-xenon.h"
26 
27 static int xenon_enable_internal_clk(struct sdhci_host *host)
28 {
29 	u32 reg;
30 	ktime_t timeout;
31 
32 	reg = sdhci_readl(host, SDHCI_CLOCK_CONTROL);
33 	reg |= SDHCI_CLOCK_INT_EN;
34 	sdhci_writel(host, reg, SDHCI_CLOCK_CONTROL);
35 	/* Wait max 20 ms */
36 	timeout = ktime_add_ms(ktime_get(), 20);
37 	while (!((reg = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
38 			& SDHCI_CLOCK_INT_STABLE)) {
39 		if (ktime_after(ktime_get(), timeout)) {
40 			dev_err(mmc_dev(host->mmc), "Internal clock never stabilised.\n");
41 			return -ETIMEDOUT;
42 		}
43 		usleep_range(900, 1100);
44 	}
45 
46 	return 0;
47 }
48 
49 /* Set SDCLK-off-while-idle */
50 static void xenon_set_sdclk_off_idle(struct sdhci_host *host,
51 				     unsigned char sdhc_id, bool enable)
52 {
53 	u32 reg;
54 	u32 mask;
55 
56 	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
57 	/* Get the bit shift basing on the SDHC index */
58 	mask = (0x1 << (XENON_SDCLK_IDLEOFF_ENABLE_SHIFT + sdhc_id));
59 	if (enable)
60 		reg |= mask;
61 	else
62 		reg &= ~mask;
63 
64 	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
65 }
66 
67 /* Enable/Disable the Auto Clock Gating function */
68 static void xenon_set_acg(struct sdhci_host *host, bool enable)
69 {
70 	u32 reg;
71 
72 	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
73 	if (enable)
74 		reg &= ~XENON_AUTO_CLKGATE_DISABLE_MASK;
75 	else
76 		reg |= XENON_AUTO_CLKGATE_DISABLE_MASK;
77 	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
78 }
79 
80 /* Enable this SDHC */
81 static void xenon_enable_sdhc(struct sdhci_host *host,
82 			      unsigned char sdhc_id)
83 {
84 	u32 reg;
85 
86 	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
87 	reg |= (BIT(sdhc_id) << XENON_SLOT_ENABLE_SHIFT);
88 	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
89 
90 	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
91 	/*
92 	 * Force to clear BUS_TEST to
93 	 * skip bus_test_pre and bus_test_post
94 	 */
95 	host->mmc->caps &= ~MMC_CAP_BUS_WIDTH_TEST;
96 }
97 
98 /* Disable this SDHC */
99 static void xenon_disable_sdhc(struct sdhci_host *host,
100 			       unsigned char sdhc_id)
101 {
102 	u32 reg;
103 
104 	reg = sdhci_readl(host, XENON_SYS_OP_CTRL);
105 	reg &= ~(BIT(sdhc_id) << XENON_SLOT_ENABLE_SHIFT);
106 	sdhci_writel(host, reg, XENON_SYS_OP_CTRL);
107 }
108 
109 /* Enable Parallel Transfer Mode */
110 static void xenon_enable_sdhc_parallel_tran(struct sdhci_host *host,
111 					    unsigned char sdhc_id)
112 {
113 	u32 reg;
114 
115 	reg = sdhci_readl(host, XENON_SYS_EXT_OP_CTRL);
116 	reg |= BIT(sdhc_id);
117 	sdhci_writel(host, reg, XENON_SYS_EXT_OP_CTRL);
118 }
119 
120 /* Mask command conflict error */
121 static void xenon_mask_cmd_conflict_err(struct sdhci_host *host)
122 {
123 	u32  reg;
124 
125 	reg = sdhci_readl(host, XENON_SYS_EXT_OP_CTRL);
126 	reg |= XENON_MASK_CMD_CONFLICT_ERR;
127 	sdhci_writel(host, reg, XENON_SYS_EXT_OP_CTRL);
128 }
129 
130 static void xenon_retune_setup(struct sdhci_host *host)
131 {
132 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
133 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
134 	u32 reg;
135 
136 	/* Disable the Re-Tuning Request functionality */
137 	reg = sdhci_readl(host, XENON_SLOT_RETUNING_REQ_CTRL);
138 	reg &= ~XENON_RETUNING_COMPATIBLE;
139 	sdhci_writel(host, reg, XENON_SLOT_RETUNING_REQ_CTRL);
140 
141 	/* Disable the Re-tuning Interrupt */
142 	reg = sdhci_readl(host, SDHCI_SIGNAL_ENABLE);
143 	reg &= ~SDHCI_INT_RETUNE;
144 	sdhci_writel(host, reg, SDHCI_SIGNAL_ENABLE);
145 	reg = sdhci_readl(host, SDHCI_INT_ENABLE);
146 	reg &= ~SDHCI_INT_RETUNE;
147 	sdhci_writel(host, reg, SDHCI_INT_ENABLE);
148 
149 	/* Force to use Tuning Mode 1 */
150 	host->tuning_mode = SDHCI_TUNING_MODE_1;
151 	/* Set re-tuning period */
152 	host->tuning_count = 1 << (priv->tuning_count - 1);
153 }
154 
155 /*
156  * Operations inside struct sdhci_ops
157  */
158 /* Recover the Register Setting cleared during SOFTWARE_RESET_ALL */
159 static void xenon_reset_exit(struct sdhci_host *host,
160 			     unsigned char sdhc_id, u8 mask)
161 {
162 	/* Only SOFTWARE RESET ALL will clear the register setting */
163 	if (!(mask & SDHCI_RESET_ALL))
164 		return;
165 
166 	/* Disable tuning request and auto-retuning again */
167 	xenon_retune_setup(host);
168 
169 	xenon_set_acg(host, true);
170 
171 	xenon_set_sdclk_off_idle(host, sdhc_id, false);
172 
173 	xenon_mask_cmd_conflict_err(host);
174 }
175 
176 static void xenon_reset(struct sdhci_host *host, u8 mask)
177 {
178 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
179 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
180 
181 	sdhci_reset(host, mask);
182 	xenon_reset_exit(host, priv->sdhc_id, mask);
183 }
184 
185 /*
186  * Xenon defines different values for HS200 and HS400
187  * in Host_Control_2
188  */
189 static void xenon_set_uhs_signaling(struct sdhci_host *host,
190 				    unsigned int timing)
191 {
192 	u16 ctrl_2;
193 
194 	ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
195 	/* Select Bus Speed Mode for host */
196 	ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
197 	if (timing == MMC_TIMING_MMC_HS200)
198 		ctrl_2 |= XENON_CTRL_HS200;
199 	else if (timing == MMC_TIMING_UHS_SDR104)
200 		ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
201 	else if (timing == MMC_TIMING_UHS_SDR12)
202 		ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
203 	else if (timing == MMC_TIMING_UHS_SDR25)
204 		ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
205 	else if (timing == MMC_TIMING_UHS_SDR50)
206 		ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
207 	else if ((timing == MMC_TIMING_UHS_DDR50) ||
208 		 (timing == MMC_TIMING_MMC_DDR52))
209 		ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
210 	else if (timing == MMC_TIMING_MMC_HS400)
211 		ctrl_2 |= XENON_CTRL_HS400;
212 	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
213 }
214 
215 static void xenon_set_power(struct sdhci_host *host, unsigned char mode,
216 		unsigned short vdd)
217 {
218 	struct mmc_host *mmc = host->mmc;
219 	u8 pwr = host->pwr;
220 
221 	sdhci_set_power_noreg(host, mode, vdd);
222 
223 	if (host->pwr == pwr)
224 		return;
225 
226 	if (host->pwr == 0)
227 		vdd = 0;
228 
229 	if (!IS_ERR(mmc->supply.vmmc))
230 		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
231 }
232 
233 static const struct sdhci_ops sdhci_xenon_ops = {
234 	.set_clock		= sdhci_set_clock,
235 	.set_power		= xenon_set_power,
236 	.set_bus_width		= sdhci_set_bus_width,
237 	.reset			= xenon_reset,
238 	.set_uhs_signaling	= xenon_set_uhs_signaling,
239 	.get_max_clock		= sdhci_pltfm_clk_get_max_clock,
240 };
241 
242 static const struct sdhci_pltfm_data sdhci_xenon_pdata = {
243 	.ops = &sdhci_xenon_ops,
244 	.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
245 		  SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER |
246 		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
247 };
248 
249 /*
250  * Xenon Specific Operations in mmc_host_ops
251  */
252 static void xenon_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
253 {
254 	struct sdhci_host *host = mmc_priv(mmc);
255 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
256 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
257 	u32 reg;
258 
259 	/*
260 	 * HS400/HS200/eMMC HS doesn't have Preset Value register.
261 	 * However, sdhci_set_ios will read HS400/HS200 Preset register.
262 	 * Disable Preset Value register for HS400/HS200.
263 	 * eMMC HS with preset_enabled set will trigger a bug in
264 	 * get_preset_value().
265 	 */
266 	if ((ios->timing == MMC_TIMING_MMC_HS400) ||
267 	    (ios->timing == MMC_TIMING_MMC_HS200) ||
268 	    (ios->timing == MMC_TIMING_MMC_HS)) {
269 		host->preset_enabled = false;
270 		host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
271 		host->flags &= ~SDHCI_PV_ENABLED;
272 
273 		reg = sdhci_readw(host, SDHCI_HOST_CONTROL2);
274 		reg &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;
275 		sdhci_writew(host, reg, SDHCI_HOST_CONTROL2);
276 	} else {
277 		host->quirks2 &= ~SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
278 	}
279 
280 	sdhci_set_ios(mmc, ios);
281 	xenon_phy_adj(host, ios);
282 
283 	if (host->clock > XENON_DEFAULT_SDCLK_FREQ)
284 		xenon_set_sdclk_off_idle(host, priv->sdhc_id, true);
285 }
286 
287 static int xenon_start_signal_voltage_switch(struct mmc_host *mmc,
288 					     struct mmc_ios *ios)
289 {
290 	struct sdhci_host *host = mmc_priv(mmc);
291 
292 	/*
293 	 * Before SD/SDIO set signal voltage, SD bus clock should be
294 	 * disabled. However, sdhci_set_clock will also disable the Internal
295 	 * clock in mmc_set_signal_voltage().
296 	 * If Internal clock is disabled, the 3.3V/1.8V bit can not be updated.
297 	 * Thus here manually enable internal clock.
298 	 *
299 	 * After switch completes, it is unnecessary to disable internal clock,
300 	 * since keeping internal clock active obeys SD spec.
301 	 */
302 	xenon_enable_internal_clk(host);
303 
304 	xenon_soc_pad_ctrl(host, ios->signal_voltage);
305 
306 	/*
307 	 * If Vqmmc is fixed on platform, vqmmc regulator should be unavailable.
308 	 * Thus SDHCI_CTRL_VDD_180 bit might not work then.
309 	 * Skip the standard voltage switch to avoid any issue.
310 	 */
311 	if (PTR_ERR(mmc->supply.vqmmc) == -ENODEV)
312 		return 0;
313 
314 	return sdhci_start_signal_voltage_switch(mmc, ios);
315 }
316 
317 /*
318  * Update card type.
319  * priv->init_card_type will be used in PHY timing adjustment.
320  */
321 static void xenon_init_card(struct mmc_host *mmc, struct mmc_card *card)
322 {
323 	struct sdhci_host *host = mmc_priv(mmc);
324 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
325 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
326 
327 	/* Update card type*/
328 	priv->init_card_type = card->type;
329 }
330 
331 static int xenon_execute_tuning(struct mmc_host *mmc, u32 opcode)
332 {
333 	struct sdhci_host *host = mmc_priv(mmc);
334 
335 	if (host->timing == MMC_TIMING_UHS_DDR50 ||
336 		host->timing == MMC_TIMING_MMC_DDR52)
337 		return 0;
338 
339 	/*
340 	 * Currently force Xenon driver back to support mode 1 only,
341 	 * even though Xenon might claim to support mode 2 or mode 3.
342 	 * It requires more time to test mode 2/mode 3 on more platforms.
343 	 */
344 	if (host->tuning_mode != SDHCI_TUNING_MODE_1)
345 		xenon_retune_setup(host);
346 
347 	return sdhci_execute_tuning(mmc, opcode);
348 }
349 
350 static void xenon_enable_sdio_irq(struct mmc_host *mmc, int enable)
351 {
352 	struct sdhci_host *host = mmc_priv(mmc);
353 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
354 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
355 	u32 reg;
356 	u8 sdhc_id = priv->sdhc_id;
357 
358 	sdhci_enable_sdio_irq(mmc, enable);
359 
360 	if (enable) {
361 		/*
362 		 * Set SDIO Card Inserted indication
363 		 * to enable detecting SDIO async irq.
364 		 */
365 		reg = sdhci_readl(host, XENON_SYS_CFG_INFO);
366 		reg |= (1 << (sdhc_id + XENON_SLOT_TYPE_SDIO_SHIFT));
367 		sdhci_writel(host, reg, XENON_SYS_CFG_INFO);
368 	} else {
369 		/* Clear SDIO Card Inserted indication */
370 		reg = sdhci_readl(host, XENON_SYS_CFG_INFO);
371 		reg &= ~(1 << (sdhc_id + XENON_SLOT_TYPE_SDIO_SHIFT));
372 		sdhci_writel(host, reg, XENON_SYS_CFG_INFO);
373 	}
374 }
375 
376 static void xenon_replace_mmc_host_ops(struct sdhci_host *host)
377 {
378 	host->mmc_host_ops.set_ios = xenon_set_ios;
379 	host->mmc_host_ops.start_signal_voltage_switch =
380 			xenon_start_signal_voltage_switch;
381 	host->mmc_host_ops.init_card = xenon_init_card;
382 	host->mmc_host_ops.execute_tuning = xenon_execute_tuning;
383 	host->mmc_host_ops.enable_sdio_irq = xenon_enable_sdio_irq;
384 }
385 
386 /*
387  * Parse Xenon specific DT properties:
388  * sdhc-id: the index of current SDHC.
389  *	    Refer to XENON_SYS_CFG_INFO register
390  * tun-count: the interval between re-tuning
391  */
392 static int xenon_probe_dt(struct platform_device *pdev)
393 {
394 	struct device_node *np = pdev->dev.of_node;
395 	struct sdhci_host *host = platform_get_drvdata(pdev);
396 	struct mmc_host *mmc = host->mmc;
397 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
398 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
399 	u32 sdhc_id, nr_sdhc;
400 	u32 tuning_count;
401 
402 	/* Disable HS200 on Armada AP806 */
403 	if (of_device_is_compatible(np, "marvell,armada-ap806-sdhci"))
404 		host->quirks2 |= SDHCI_QUIRK2_BROKEN_HS200;
405 
406 	sdhc_id = 0x0;
407 	if (!of_property_read_u32(np, "marvell,xenon-sdhc-id", &sdhc_id)) {
408 		nr_sdhc = sdhci_readl(host, XENON_SYS_CFG_INFO);
409 		nr_sdhc &= XENON_NR_SUPPORTED_SLOT_MASK;
410 		if (unlikely(sdhc_id > nr_sdhc)) {
411 			dev_err(mmc_dev(mmc), "SDHC Index %d exceeds Number of SDHCs %d\n",
412 				sdhc_id, nr_sdhc);
413 			return -EINVAL;
414 		}
415 	}
416 	priv->sdhc_id = sdhc_id;
417 
418 	tuning_count = XENON_DEF_TUNING_COUNT;
419 	if (!of_property_read_u32(np, "marvell,xenon-tun-count",
420 				  &tuning_count)) {
421 		if (unlikely(tuning_count >= XENON_TMR_RETUN_NO_PRESENT)) {
422 			dev_err(mmc_dev(mmc), "Wrong Re-tuning Count. Set default value %d\n",
423 				XENON_DEF_TUNING_COUNT);
424 			tuning_count = XENON_DEF_TUNING_COUNT;
425 		}
426 	}
427 	priv->tuning_count = tuning_count;
428 
429 	return xenon_phy_parse_dt(np, host);
430 }
431 
432 static int xenon_sdhc_prepare(struct sdhci_host *host)
433 {
434 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
435 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
436 	u8 sdhc_id = priv->sdhc_id;
437 
438 	/* Enable SDHC */
439 	xenon_enable_sdhc(host, sdhc_id);
440 
441 	/* Enable ACG */
442 	xenon_set_acg(host, true);
443 
444 	/* Enable Parallel Transfer Mode */
445 	xenon_enable_sdhc_parallel_tran(host, sdhc_id);
446 
447 	/* Disable SDCLK-Off-While-Idle before card init */
448 	xenon_set_sdclk_off_idle(host, sdhc_id, false);
449 
450 	xenon_mask_cmd_conflict_err(host);
451 
452 	return 0;
453 }
454 
455 static void xenon_sdhc_unprepare(struct sdhci_host *host)
456 {
457 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
458 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
459 	u8 sdhc_id = priv->sdhc_id;
460 
461 	/* disable SDHC */
462 	xenon_disable_sdhc(host, sdhc_id);
463 }
464 
465 static int xenon_probe(struct platform_device *pdev)
466 {
467 	struct sdhci_pltfm_host *pltfm_host;
468 	struct sdhci_host *host;
469 	int err;
470 
471 	host = sdhci_pltfm_init(pdev, &sdhci_xenon_pdata,
472 				sizeof(struct xenon_priv));
473 	if (IS_ERR(host))
474 		return PTR_ERR(host);
475 
476 	pltfm_host = sdhci_priv(host);
477 
478 	/*
479 	 * Link Xenon specific mmc_host_ops function,
480 	 * to replace standard ones in sdhci_ops.
481 	 */
482 	xenon_replace_mmc_host_ops(host);
483 
484 	pltfm_host->clk = devm_clk_get(&pdev->dev, "core");
485 	if (IS_ERR(pltfm_host->clk)) {
486 		err = PTR_ERR(pltfm_host->clk);
487 		dev_err(&pdev->dev, "Failed to setup input clk: %d\n", err);
488 		goto free_pltfm;
489 	}
490 	err = clk_prepare_enable(pltfm_host->clk);
491 	if (err)
492 		goto free_pltfm;
493 
494 	err = mmc_of_parse(host->mmc);
495 	if (err)
496 		goto err_clk;
497 
498 	sdhci_get_of_property(pdev);
499 
500 	xenon_set_acg(host, false);
501 
502 	/* Xenon specific dt parse */
503 	err = xenon_probe_dt(pdev);
504 	if (err)
505 		goto err_clk;
506 
507 	err = xenon_sdhc_prepare(host);
508 	if (err)
509 		goto err_clk;
510 
511 	pm_runtime_get_noresume(&pdev->dev);
512 	pm_runtime_set_active(&pdev->dev);
513 	pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
514 	pm_runtime_use_autosuspend(&pdev->dev);
515 	pm_runtime_enable(&pdev->dev);
516 	pm_suspend_ignore_children(&pdev->dev, 1);
517 
518 	err = sdhci_add_host(host);
519 	if (err)
520 		goto remove_sdhc;
521 
522 	pm_runtime_put_autosuspend(&pdev->dev);
523 
524 	return 0;
525 
526 remove_sdhc:
527 	pm_runtime_disable(&pdev->dev);
528 	pm_runtime_put_noidle(&pdev->dev);
529 	xenon_sdhc_unprepare(host);
530 err_clk:
531 	clk_disable_unprepare(pltfm_host->clk);
532 free_pltfm:
533 	sdhci_pltfm_free(pdev);
534 	return err;
535 }
536 
537 static int xenon_remove(struct platform_device *pdev)
538 {
539 	struct sdhci_host *host = platform_get_drvdata(pdev);
540 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
541 
542 	pm_runtime_get_sync(&pdev->dev);
543 	pm_runtime_disable(&pdev->dev);
544 	pm_runtime_put_noidle(&pdev->dev);
545 
546 	sdhci_remove_host(host, 0);
547 
548 	xenon_sdhc_unprepare(host);
549 
550 	clk_disable_unprepare(pltfm_host->clk);
551 
552 	sdhci_pltfm_free(pdev);
553 
554 	return 0;
555 }
556 
557 #ifdef CONFIG_PM_SLEEP
558 static int xenon_suspend(struct device *dev)
559 {
560 	struct sdhci_host *host = dev_get_drvdata(dev);
561 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
562 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
563 	int ret;
564 
565 	ret = pm_runtime_force_suspend(dev);
566 
567 	priv->restore_needed = true;
568 	return ret;
569 }
570 #endif
571 
572 #ifdef CONFIG_PM
573 static int xenon_runtime_suspend(struct device *dev)
574 {
575 	struct sdhci_host *host = dev_get_drvdata(dev);
576 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
577 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
578 	int ret;
579 
580 	ret = sdhci_runtime_suspend_host(host);
581 	if (ret)
582 		return ret;
583 
584 	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
585 		mmc_retune_needed(host->mmc);
586 
587 	clk_disable_unprepare(pltfm_host->clk);
588 	/*
589 	 * Need to update the priv->clock here, or when runtime resume
590 	 * back, phy don't aware the clock change and won't adjust phy
591 	 * which will cause cmd err
592 	 */
593 	priv->clock = 0;
594 	return 0;
595 }
596 
597 static int xenon_runtime_resume(struct device *dev)
598 {
599 	struct sdhci_host *host = dev_get_drvdata(dev);
600 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
601 	struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
602 	int ret;
603 
604 	ret = clk_prepare_enable(pltfm_host->clk);
605 	if (ret) {
606 		dev_err(dev, "can't enable mainck\n");
607 		return ret;
608 	}
609 
610 	if (priv->restore_needed) {
611 		ret = xenon_sdhc_prepare(host);
612 		if (ret)
613 			goto out;
614 		priv->restore_needed = false;
615 	}
616 
617 	ret = sdhci_runtime_resume_host(host);
618 	if (ret)
619 		goto out;
620 	return 0;
621 out:
622 	clk_disable_unprepare(pltfm_host->clk);
623 	return ret;
624 }
625 #endif /* CONFIG_PM */
626 
627 static const struct dev_pm_ops sdhci_xenon_dev_pm_ops = {
628 	SET_SYSTEM_SLEEP_PM_OPS(xenon_suspend,
629 				pm_runtime_force_resume)
630 	SET_RUNTIME_PM_OPS(xenon_runtime_suspend,
631 			   xenon_runtime_resume,
632 			   NULL)
633 };
634 
635 static const struct of_device_id sdhci_xenon_dt_ids[] = {
636 	{ .compatible = "marvell,armada-ap806-sdhci",},
637 	{ .compatible = "marvell,armada-cp110-sdhci",},
638 	{ .compatible = "marvell,armada-3700-sdhci",},
639 	{}
640 };
641 MODULE_DEVICE_TABLE(of, sdhci_xenon_dt_ids);
642 
643 static struct platform_driver sdhci_xenon_driver = {
644 	.driver	= {
645 		.name	= "xenon-sdhci",
646 		.of_match_table = sdhci_xenon_dt_ids,
647 		.pm = &sdhci_xenon_dev_pm_ops,
648 	},
649 	.probe	= xenon_probe,
650 	.remove	= xenon_remove,
651 };
652 
653 module_platform_driver(sdhci_xenon_driver);
654 
655 MODULE_DESCRIPTION("SDHCI platform driver for Marvell Xenon SDHC");
656 MODULE_AUTHOR("Hu Ziji <huziji@marvell.com>");
657 MODULE_LICENSE("GPL v2");
658