xref: /linux/drivers/mmc/host/mmci_stm32_sdmmc.c (revision 6de298ff13a807d12300bd616c6d3039987e6e87)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
4  * Author: Ludovic.barre@st.com for STMicroelectronics.
5  */
6 #include <linux/bitfield.h>
7 #include <linux/delay.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/iopoll.h>
10 #include <linux/mmc/host.h>
11 #include <linux/mmc/card.h>
12 #include <linux/of_address.h>
13 #include <linux/reset.h>
14 #include <linux/scatterlist.h>
15 #include "mmci.h"
16 
17 #define SDMMC_LLI_BUF_LEN	PAGE_SIZE
18 
19 #define DLYB_CR			0x0
20 #define DLYB_CR_DEN		BIT(0)
21 #define DLYB_CR_SEN		BIT(1)
22 
23 #define DLYB_CFGR		0x4
24 #define DLYB_CFGR_SEL_MASK	GENMASK(3, 0)
25 #define DLYB_CFGR_UNIT_MASK	GENMASK(14, 8)
26 #define DLYB_CFGR_LNG_MASK	GENMASK(27, 16)
27 #define DLYB_CFGR_LNGF		BIT(31)
28 
29 #define DLYB_NB_DELAY		11
30 #define DLYB_CFGR_SEL_MAX	(DLYB_NB_DELAY + 1)
31 #define DLYB_CFGR_UNIT_MAX	127
32 
33 #define DLYB_LNG_TIMEOUT_US	1000
34 #define SDMMC_VSWEND_TIMEOUT_US 10000
35 
36 #define SYSCFG_DLYBSD_CR	0x0
37 #define DLYBSD_CR_EN		BIT(0)
38 #define DLYBSD_CR_RXTAPSEL_MASK	GENMASK(6, 1)
39 #define DLYBSD_TAPSEL_NB	32
40 #define DLYBSD_BYP_EN		BIT(16)
41 #define DLYBSD_BYP_CMD		GENMASK(21, 17)
42 #define DLYBSD_ANTIGLITCH_EN	BIT(22)
43 
44 #define SYSCFG_DLYBSD_SR	0x4
45 #define DLYBSD_SR_LOCK		BIT(0)
46 #define DLYBSD_SR_RXTAPSEL_ACK	BIT(1)
47 
48 #define DLYBSD_TIMEOUT_1S_IN_US	1000000
49 
50 struct sdmmc_lli_desc {
51 	u32 idmalar;
52 	u32 idmabase;
53 	u32 idmasize;
54 };
55 
56 struct sdmmc_idma {
57 	dma_addr_t sg_dma;
58 	void *sg_cpu;
59 	dma_addr_t bounce_dma_addr;
60 	void *bounce_buf;
61 	bool use_bounce_buffer;
62 };
63 
64 struct sdmmc_dlyb;
65 
66 struct sdmmc_tuning_ops {
67 	int (*dlyb_enable)(struct sdmmc_dlyb *dlyb);
68 	void (*set_input_ck)(struct sdmmc_dlyb *dlyb);
69 	int (*tuning_prepare)(struct mmci_host *host);
70 	int (*set_cfg)(struct sdmmc_dlyb *dlyb, int unit __maybe_unused,
71 		       int phase, bool sampler __maybe_unused);
72 };
73 
74 struct sdmmc_dlyb {
75 	void __iomem *base;
76 	u32 unit;
77 	u32 max;
78 	struct sdmmc_tuning_ops *ops;
79 };
80 
81 static int sdmmc_idma_validate_data(struct mmci_host *host,
82 				    struct mmc_data *data)
83 {
84 	struct sdmmc_idma *idma = host->dma_priv;
85 	struct device *dev = mmc_dev(host->mmc);
86 	struct scatterlist *sg;
87 	int i;
88 
89 	/*
90 	 * idma has constraints on idmabase & idmasize for each element
91 	 * excepted the last element which has no constraint on idmasize
92 	 */
93 	idma->use_bounce_buffer = false;
94 	for_each_sg(data->sg, sg, data->sg_len - 1, i) {
95 		if (!IS_ALIGNED(sg->offset, sizeof(u32)) ||
96 		    !IS_ALIGNED(sg->length,
97 				host->variant->stm32_idmabsize_align)) {
98 			dev_dbg(mmc_dev(host->mmc),
99 				"unaligned scatterlist: ofst:%x length:%d\n",
100 				data->sg->offset, data->sg->length);
101 			goto use_bounce_buffer;
102 		}
103 	}
104 
105 	if (!IS_ALIGNED(sg->offset, sizeof(u32))) {
106 		dev_dbg(mmc_dev(host->mmc),
107 			"unaligned last scatterlist: ofst:%x length:%d\n",
108 			data->sg->offset, data->sg->length);
109 		goto use_bounce_buffer;
110 	}
111 
112 	return 0;
113 
114 use_bounce_buffer:
115 	if (!idma->bounce_buf) {
116 		idma->bounce_buf = dmam_alloc_coherent(dev,
117 						       host->mmc->max_req_size,
118 						       &idma->bounce_dma_addr,
119 						       GFP_KERNEL);
120 		if (!idma->bounce_buf) {
121 			dev_err(dev, "Unable to map allocate DMA bounce buffer.\n");
122 			return -ENOMEM;
123 		}
124 	}
125 
126 	idma->use_bounce_buffer = true;
127 
128 	return 0;
129 }
130 
131 static int _sdmmc_idma_prep_data(struct mmci_host *host,
132 				 struct mmc_data *data)
133 {
134 	struct sdmmc_idma *idma = host->dma_priv;
135 
136 	if (idma->use_bounce_buffer) {
137 		if (data->flags & MMC_DATA_WRITE) {
138 			unsigned int xfer_bytes = data->blksz * data->blocks;
139 
140 			sg_copy_to_buffer(data->sg, data->sg_len,
141 					  idma->bounce_buf, xfer_bytes);
142 			dma_wmb();
143 		}
144 	} else {
145 		int n_elem;
146 
147 		n_elem = dma_map_sg(mmc_dev(host->mmc),
148 				    data->sg,
149 				    data->sg_len,
150 				    mmc_get_dma_dir(data));
151 
152 		if (!n_elem) {
153 			dev_err(mmc_dev(host->mmc), "dma_map_sg failed\n");
154 			return -EINVAL;
155 		}
156 	}
157 	return 0;
158 }
159 
160 static int sdmmc_idma_prep_data(struct mmci_host *host,
161 				struct mmc_data *data, bool next)
162 {
163 	/* Check if job is already prepared. */
164 	if (!next && data->host_cookie == host->next_cookie)
165 		return 0;
166 
167 	return _sdmmc_idma_prep_data(host, data);
168 }
169 
170 static void sdmmc_idma_unprep_data(struct mmci_host *host,
171 				   struct mmc_data *data, int err)
172 {
173 	struct sdmmc_idma *idma = host->dma_priv;
174 
175 	if (idma->use_bounce_buffer) {
176 		if (data->flags & MMC_DATA_READ) {
177 			unsigned int xfer_bytes = data->blksz * data->blocks;
178 
179 			sg_copy_from_buffer(data->sg, data->sg_len,
180 					    idma->bounce_buf, xfer_bytes);
181 		}
182 	} else {
183 		dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
184 			     mmc_get_dma_dir(data));
185 	}
186 }
187 
188 static int sdmmc_idma_setup(struct mmci_host *host)
189 {
190 	struct sdmmc_idma *idma;
191 	struct device *dev = mmc_dev(host->mmc);
192 
193 	idma = devm_kzalloc(dev, sizeof(*idma), GFP_KERNEL);
194 	if (!idma)
195 		return -ENOMEM;
196 
197 	host->dma_priv = idma;
198 
199 	if (host->variant->dma_lli) {
200 		idma->sg_cpu = dmam_alloc_coherent(dev, SDMMC_LLI_BUF_LEN,
201 						   &idma->sg_dma, GFP_KERNEL);
202 		if (!idma->sg_cpu) {
203 			dev_err(dev, "Failed to alloc IDMA descriptor\n");
204 			return -ENOMEM;
205 		}
206 		host->mmc->max_segs = SDMMC_LLI_BUF_LEN /
207 			sizeof(struct sdmmc_lli_desc);
208 		host->mmc->max_seg_size = host->variant->stm32_idmabsize_mask;
209 
210 		host->mmc->max_req_size = SZ_1M;
211 	} else {
212 		host->mmc->max_segs = 1;
213 		host->mmc->max_seg_size = host->mmc->max_req_size;
214 	}
215 
216 	return dma_set_max_seg_size(dev, host->mmc->max_seg_size);
217 }
218 
219 static int sdmmc_idma_start(struct mmci_host *host, unsigned int *datactrl)
220 
221 {
222 	struct sdmmc_idma *idma = host->dma_priv;
223 	struct sdmmc_lli_desc *desc = (struct sdmmc_lli_desc *)idma->sg_cpu;
224 	struct mmc_data *data = host->data;
225 	struct scatterlist *sg;
226 	int i;
227 
228 	if (!host->variant->dma_lli || data->sg_len == 1 ||
229 	    idma->use_bounce_buffer) {
230 		u32 dma_addr;
231 
232 		if (idma->use_bounce_buffer)
233 			dma_addr = idma->bounce_dma_addr;
234 		else
235 			dma_addr = sg_dma_address(data->sg);
236 
237 		writel_relaxed(dma_addr,
238 			       host->base + MMCI_STM32_IDMABASE0R);
239 		writel_relaxed(MMCI_STM32_IDMAEN,
240 			       host->base + MMCI_STM32_IDMACTRLR);
241 		return 0;
242 	}
243 
244 	for_each_sg(data->sg, sg, data->sg_len, i) {
245 		desc[i].idmalar = (i + 1) * sizeof(struct sdmmc_lli_desc);
246 		desc[i].idmalar |= MMCI_STM32_ULA | MMCI_STM32_ULS
247 			| MMCI_STM32_ABR;
248 		desc[i].idmabase = sg_dma_address(sg);
249 		desc[i].idmasize = sg_dma_len(sg);
250 	}
251 
252 	/* notice the end of link list */
253 	desc[data->sg_len - 1].idmalar &= ~MMCI_STM32_ULA;
254 
255 	dma_wmb();
256 	writel_relaxed(idma->sg_dma, host->base + MMCI_STM32_IDMABAR);
257 	writel_relaxed(desc[0].idmalar, host->base + MMCI_STM32_IDMALAR);
258 	writel_relaxed(desc[0].idmabase, host->base + MMCI_STM32_IDMABASE0R);
259 	writel_relaxed(desc[0].idmasize, host->base + MMCI_STM32_IDMABSIZER);
260 	writel_relaxed(MMCI_STM32_IDMAEN | MMCI_STM32_IDMALLIEN,
261 		       host->base + MMCI_STM32_IDMACTRLR);
262 
263 	return 0;
264 }
265 
266 static void sdmmc_idma_finalize(struct mmci_host *host, struct mmc_data *data)
267 {
268 	writel_relaxed(0, host->base + MMCI_STM32_IDMACTRLR);
269 
270 	if (!data->host_cookie)
271 		sdmmc_idma_unprep_data(host, data, 0);
272 }
273 
274 static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired)
275 {
276 	unsigned int clk = 0, ddr = 0;
277 
278 	if (host->mmc->ios.timing == MMC_TIMING_MMC_DDR52 ||
279 	    host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
280 		ddr = MCI_STM32_CLK_DDR;
281 
282 	/*
283 	 * cclk = mclk / (2 * clkdiv)
284 	 * clkdiv 0 => bypass
285 	 * in ddr mode bypass is not possible
286 	 */
287 	if (desired) {
288 		if (desired >= host->mclk && !ddr) {
289 			host->cclk = host->mclk;
290 		} else {
291 			clk = DIV_ROUND_UP(host->mclk, 2 * desired);
292 			if (clk > MCI_STM32_CLK_CLKDIV_MSK)
293 				clk = MCI_STM32_CLK_CLKDIV_MSK;
294 			host->cclk = host->mclk / (2 * clk);
295 		}
296 	} else {
297 		/*
298 		 * while power-on phase the clock can't be define to 0,
299 		 * Only power-off and power-cyc deactivate the clock.
300 		 * if desired clock is 0, set max divider
301 		 */
302 		clk = MCI_STM32_CLK_CLKDIV_MSK;
303 		host->cclk = host->mclk / (2 * clk);
304 	}
305 
306 	/* Set actual clock for debug */
307 	if (host->mmc->ios.power_mode == MMC_POWER_ON)
308 		host->mmc->actual_clock = host->cclk;
309 	else
310 		host->mmc->actual_clock = 0;
311 
312 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
313 		clk |= MCI_STM32_CLK_WIDEBUS_4;
314 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
315 		clk |= MCI_STM32_CLK_WIDEBUS_8;
316 
317 	clk |= MCI_STM32_CLK_HWFCEN;
318 	clk |= host->clk_reg_add;
319 	clk |= ddr;
320 
321 	if (host->mmc->ios.timing >= MMC_TIMING_UHS_SDR50)
322 		clk |= MCI_STM32_CLK_BUSSPEED;
323 
324 	mmci_write_clkreg(host, clk);
325 }
326 
327 static void sdmmc_dlyb_mp15_input_ck(struct sdmmc_dlyb *dlyb)
328 {
329 	if (!dlyb || !dlyb->base)
330 		return;
331 
332 	/* Output clock = Input clock */
333 	writel_relaxed(0, dlyb->base + DLYB_CR);
334 }
335 
336 static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr)
337 {
338 	struct mmc_ios ios = host->mmc->ios;
339 	struct sdmmc_dlyb *dlyb = host->variant_priv;
340 
341 	/* adds OF options */
342 	pwr = host->pwr_reg_add;
343 
344 	if (dlyb && dlyb->ops->set_input_ck)
345 		dlyb->ops->set_input_ck(dlyb);
346 
347 	if (ios.power_mode == MMC_POWER_OFF) {
348 		/* Only a reset could power-off sdmmc */
349 		reset_control_assert(host->rst);
350 		udelay(2);
351 		reset_control_deassert(host->rst);
352 
353 		/*
354 		 * Set the SDMMC in Power-cycle state.
355 		 * This will make that the SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK
356 		 * are driven low, to prevent the Card from being supplied
357 		 * through the signal lines.
358 		 */
359 		mmci_write_pwrreg(host, MCI_STM32_PWR_CYC | pwr);
360 	} else if (ios.power_mode == MMC_POWER_ON) {
361 		/*
362 		 * After power-off (reset): the irq mask defined in probe
363 		 * functionis lost
364 		 * ault irq mask (probe) must be activated
365 		 */
366 		writel(MCI_IRQENABLE | host->variant->start_err,
367 		       host->base + MMCIMASK0);
368 
369 		/* preserves voltage switch bits */
370 		pwr |= host->pwr_reg & (MCI_STM32_VSWITCHEN |
371 					MCI_STM32_VSWITCH);
372 
373 		/*
374 		 * After a power-cycle state, we must set the SDMMC in
375 		 * Power-off. The SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK are
376 		 * driven high. Then we can set the SDMMC to Power-on state
377 		 */
378 		mmci_write_pwrreg(host, MCI_PWR_OFF | pwr);
379 		mdelay(1);
380 		mmci_write_pwrreg(host, MCI_PWR_ON | pwr);
381 	}
382 }
383 
384 static u32 sdmmc_get_dctrl_cfg(struct mmci_host *host)
385 {
386 	u32 datactrl;
387 
388 	datactrl = mmci_dctrl_blksz(host);
389 
390 	if (host->hw_revision >= 3) {
391 		u32 thr = 0;
392 
393 		if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104 ||
394 		    host->mmc->ios.timing == MMC_TIMING_MMC_HS200) {
395 			thr = ffs(min_t(unsigned int, host->data->blksz,
396 					host->variant->fifosize));
397 			thr = min_t(u32, thr, MMCI_STM32_THR_MASK);
398 		}
399 
400 		writel_relaxed(thr, host->base + MMCI_STM32_FIFOTHRR);
401 	}
402 
403 	if (host->mmc->card && mmc_card_sdio(host->mmc->card) &&
404 	    host->data->blocks == 1)
405 		datactrl |= MCI_DPSM_STM32_MODE_SDIO;
406 	else if (host->data->stop && !host->mrq->sbc)
407 		datactrl |= MCI_DPSM_STM32_MODE_BLOCK_STOP;
408 	else
409 		datactrl |= MCI_DPSM_STM32_MODE_BLOCK;
410 
411 	return datactrl;
412 }
413 
414 static bool sdmmc_busy_complete(struct mmci_host *host, struct mmc_command *cmd,
415 				u32 status, u32 err_msk)
416 {
417 	void __iomem *base = host->base;
418 	u32 busy_d0, busy_d0end, mask, sdmmc_status;
419 
420 	mask = readl_relaxed(base + MMCIMASK0);
421 	sdmmc_status = readl_relaxed(base + MMCISTATUS);
422 	busy_d0end = sdmmc_status & MCI_STM32_BUSYD0END;
423 	busy_d0 = sdmmc_status & MCI_STM32_BUSYD0;
424 
425 	/* complete if there is an error or busy_d0end */
426 	if ((status & err_msk) || busy_d0end)
427 		goto complete;
428 
429 	/*
430 	 * On response the busy signaling is reflected in the BUSYD0 flag.
431 	 * if busy_d0 is in-progress we must activate busyd0end interrupt
432 	 * to wait this completion. Else this request has no busy step.
433 	 */
434 	if (busy_d0) {
435 		if (!host->busy_status) {
436 			writel_relaxed(mask | host->variant->busy_detect_mask,
437 				       base + MMCIMASK0);
438 			host->busy_status = status &
439 				(MCI_CMDSENT | MCI_CMDRESPEND);
440 		}
441 		return false;
442 	}
443 
444 complete:
445 	if (host->busy_status) {
446 		writel_relaxed(mask & ~host->variant->busy_detect_mask,
447 			       base + MMCIMASK0);
448 		host->busy_status = 0;
449 	}
450 
451 	writel_relaxed(host->variant->busy_detect_mask, base + MMCICLEAR);
452 
453 	return true;
454 }
455 
456 static int sdmmc_dlyb_mp15_enable(struct sdmmc_dlyb *dlyb)
457 {
458 	writel_relaxed(DLYB_CR_DEN, dlyb->base + DLYB_CR);
459 
460 	return 0;
461 }
462 
463 static int sdmmc_dlyb_mp15_set_cfg(struct sdmmc_dlyb *dlyb,
464 				   int unit, int phase, bool sampler)
465 {
466 	u32 cfgr;
467 
468 	writel_relaxed(DLYB_CR_SEN | DLYB_CR_DEN, dlyb->base + DLYB_CR);
469 
470 	cfgr = FIELD_PREP(DLYB_CFGR_UNIT_MASK, unit) |
471 	       FIELD_PREP(DLYB_CFGR_SEL_MASK, phase);
472 	writel_relaxed(cfgr, dlyb->base + DLYB_CFGR);
473 
474 	if (!sampler)
475 		writel_relaxed(DLYB_CR_DEN, dlyb->base + DLYB_CR);
476 
477 	return 0;
478 }
479 
480 static int sdmmc_dlyb_mp15_prepare(struct mmci_host *host)
481 {
482 	struct sdmmc_dlyb *dlyb = host->variant_priv;
483 	u32 cfgr;
484 	int i, lng, ret;
485 
486 	for (i = 0; i <= DLYB_CFGR_UNIT_MAX; i++) {
487 		dlyb->ops->set_cfg(dlyb, i, DLYB_CFGR_SEL_MAX, true);
488 
489 		ret = readl_relaxed_poll_timeout(dlyb->base + DLYB_CFGR, cfgr,
490 						 (cfgr & DLYB_CFGR_LNGF),
491 						 1, DLYB_LNG_TIMEOUT_US);
492 		if (ret) {
493 			dev_warn(mmc_dev(host->mmc),
494 				 "delay line cfg timeout unit:%d cfgr:%d\n",
495 				 i, cfgr);
496 			continue;
497 		}
498 
499 		lng = FIELD_GET(DLYB_CFGR_LNG_MASK, cfgr);
500 		if (lng < BIT(DLYB_NB_DELAY) && lng > 0)
501 			break;
502 	}
503 
504 	if (i > DLYB_CFGR_UNIT_MAX)
505 		return -EINVAL;
506 
507 	dlyb->unit = i;
508 	dlyb->max = __fls(lng);
509 
510 	return 0;
511 }
512 
513 static int sdmmc_dlyb_mp25_enable(struct sdmmc_dlyb *dlyb)
514 {
515 	u32 cr, sr;
516 
517 	cr = readl_relaxed(dlyb->base + SYSCFG_DLYBSD_CR);
518 	cr |= DLYBSD_CR_EN;
519 
520 	writel_relaxed(cr, dlyb->base + SYSCFG_DLYBSD_CR);
521 
522 	return readl_relaxed_poll_timeout(dlyb->base + SYSCFG_DLYBSD_SR,
523 					   sr, sr & DLYBSD_SR_LOCK, 1,
524 					   DLYBSD_TIMEOUT_1S_IN_US);
525 }
526 
527 static int sdmmc_dlyb_mp25_set_cfg(struct sdmmc_dlyb *dlyb,
528 				   int unit __maybe_unused, int phase,
529 				   bool sampler __maybe_unused)
530 {
531 	u32 cr, sr;
532 
533 	cr = readl_relaxed(dlyb->base + SYSCFG_DLYBSD_CR);
534 	cr &= ~DLYBSD_CR_RXTAPSEL_MASK;
535 	cr |= FIELD_PREP(DLYBSD_CR_RXTAPSEL_MASK, phase);
536 
537 	writel_relaxed(cr, dlyb->base + SYSCFG_DLYBSD_CR);
538 
539 	return readl_relaxed_poll_timeout(dlyb->base + SYSCFG_DLYBSD_SR,
540 					  sr, sr & DLYBSD_SR_RXTAPSEL_ACK, 1,
541 					  DLYBSD_TIMEOUT_1S_IN_US);
542 }
543 
544 static int sdmmc_dlyb_mp25_prepare(struct mmci_host *host)
545 {
546 	struct sdmmc_dlyb *dlyb = host->variant_priv;
547 
548 	dlyb->max = DLYBSD_TAPSEL_NB;
549 
550 	return 0;
551 }
552 
553 static int sdmmc_dlyb_phase_tuning(struct mmci_host *host, u32 opcode)
554 {
555 	struct sdmmc_dlyb *dlyb = host->variant_priv;
556 	int cur_len = 0, max_len = 0, end_of_len = 0;
557 	int phase, ret;
558 
559 	for (phase = 0; phase <= dlyb->max; phase++) {
560 		ret = dlyb->ops->set_cfg(dlyb, dlyb->unit, phase, false);
561 		if (ret) {
562 			dev_err(mmc_dev(host->mmc), "tuning config failed\n");
563 			return ret;
564 		}
565 
566 		if (mmc_send_tuning(host->mmc, opcode, NULL)) {
567 			cur_len = 0;
568 		} else {
569 			cur_len++;
570 			if (cur_len > max_len) {
571 				max_len = cur_len;
572 				end_of_len = phase;
573 			}
574 		}
575 	}
576 
577 	if (!max_len) {
578 		dev_err(mmc_dev(host->mmc), "no tuning point found\n");
579 		return -EINVAL;
580 	}
581 
582 	if (dlyb->ops->set_input_ck)
583 		dlyb->ops->set_input_ck(dlyb);
584 
585 	phase = end_of_len - max_len / 2;
586 	ret = dlyb->ops->set_cfg(dlyb, dlyb->unit, phase, false);
587 	if (ret) {
588 		dev_err(mmc_dev(host->mmc), "tuning reconfig failed\n");
589 		return ret;
590 	}
591 
592 	dev_dbg(mmc_dev(host->mmc), "unit:%d max_dly:%d phase:%d\n",
593 		dlyb->unit, dlyb->max, phase);
594 
595 	return 0;
596 }
597 
598 static int sdmmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
599 {
600 	struct mmci_host *host = mmc_priv(mmc);
601 	struct sdmmc_dlyb *dlyb = host->variant_priv;
602 	u32 clk;
603 	int ret;
604 
605 	if ((host->mmc->ios.timing != MMC_TIMING_UHS_SDR104 &&
606 	     host->mmc->ios.timing != MMC_TIMING_MMC_HS200) ||
607 	    host->mmc->actual_clock <= 50000000)
608 		return 0;
609 
610 	if (!dlyb || !dlyb->base)
611 		return -EINVAL;
612 
613 	ret = dlyb->ops->dlyb_enable(dlyb);
614 	if (ret)
615 		return ret;
616 
617 	/*
618 	 * SDMMC_FBCK is selected when an external Delay Block is needed
619 	 * with SDR104 or HS200.
620 	 */
621 	clk = host->clk_reg;
622 	clk &= ~MCI_STM32_CLK_SEL_MSK;
623 	clk |= MCI_STM32_CLK_SELFBCK;
624 	mmci_write_clkreg(host, clk);
625 
626 	ret = dlyb->ops->tuning_prepare(host);
627 	if (ret)
628 		return ret;
629 
630 	return sdmmc_dlyb_phase_tuning(host, opcode);
631 }
632 
633 static void sdmmc_pre_sig_volt_vswitch(struct mmci_host *host)
634 {
635 	/* clear the voltage switch completion flag */
636 	writel_relaxed(MCI_STM32_VSWENDC, host->base + MMCICLEAR);
637 	/* enable Voltage switch procedure */
638 	mmci_write_pwrreg(host, host->pwr_reg | MCI_STM32_VSWITCHEN);
639 }
640 
641 static int sdmmc_post_sig_volt_switch(struct mmci_host *host,
642 				      struct mmc_ios *ios)
643 {
644 	unsigned long flags;
645 	u32 status;
646 	int ret = 0;
647 
648 	spin_lock_irqsave(&host->lock, flags);
649 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180 &&
650 	    host->pwr_reg & MCI_STM32_VSWITCHEN) {
651 		mmci_write_pwrreg(host, host->pwr_reg | MCI_STM32_VSWITCH);
652 		spin_unlock_irqrestore(&host->lock, flags);
653 
654 		/* wait voltage switch completion while 10ms */
655 		ret = readl_relaxed_poll_timeout(host->base + MMCISTATUS,
656 						 status,
657 						 (status & MCI_STM32_VSWEND),
658 						 10, SDMMC_VSWEND_TIMEOUT_US);
659 
660 		writel_relaxed(MCI_STM32_VSWENDC | MCI_STM32_CKSTOPC,
661 			       host->base + MMCICLEAR);
662 		spin_lock_irqsave(&host->lock, flags);
663 		mmci_write_pwrreg(host, host->pwr_reg &
664 				  ~(MCI_STM32_VSWITCHEN | MCI_STM32_VSWITCH));
665 	}
666 	spin_unlock_irqrestore(&host->lock, flags);
667 
668 	return ret;
669 }
670 
671 static struct mmci_host_ops sdmmc_variant_ops = {
672 	.validate_data = sdmmc_idma_validate_data,
673 	.prep_data = sdmmc_idma_prep_data,
674 	.unprep_data = sdmmc_idma_unprep_data,
675 	.get_datactrl_cfg = sdmmc_get_dctrl_cfg,
676 	.dma_setup = sdmmc_idma_setup,
677 	.dma_start = sdmmc_idma_start,
678 	.dma_finalize = sdmmc_idma_finalize,
679 	.set_clkreg = mmci_sdmmc_set_clkreg,
680 	.set_pwrreg = mmci_sdmmc_set_pwrreg,
681 	.busy_complete = sdmmc_busy_complete,
682 	.pre_sig_volt_switch = sdmmc_pre_sig_volt_vswitch,
683 	.post_sig_volt_switch = sdmmc_post_sig_volt_switch,
684 };
685 
686 static struct sdmmc_tuning_ops dlyb_tuning_mp15_ops = {
687 	.dlyb_enable = sdmmc_dlyb_mp15_enable,
688 	.set_input_ck = sdmmc_dlyb_mp15_input_ck,
689 	.tuning_prepare = sdmmc_dlyb_mp15_prepare,
690 	.set_cfg = sdmmc_dlyb_mp15_set_cfg,
691 };
692 
693 static struct sdmmc_tuning_ops dlyb_tuning_mp25_ops = {
694 	.dlyb_enable = sdmmc_dlyb_mp25_enable,
695 	.tuning_prepare = sdmmc_dlyb_mp25_prepare,
696 	.set_cfg = sdmmc_dlyb_mp25_set_cfg,
697 };
698 
699 void sdmmc_variant_init(struct mmci_host *host)
700 {
701 	struct device_node *np = host->mmc->parent->of_node;
702 	void __iomem *base_dlyb;
703 	struct sdmmc_dlyb *dlyb;
704 
705 	host->ops = &sdmmc_variant_ops;
706 	host->pwr_reg = readl_relaxed(host->base + MMCIPOWER);
707 
708 	base_dlyb = devm_of_iomap(mmc_dev(host->mmc), np, 1, NULL);
709 	if (IS_ERR(base_dlyb))
710 		return;
711 
712 	dlyb = devm_kzalloc(mmc_dev(host->mmc), sizeof(*dlyb), GFP_KERNEL);
713 	if (!dlyb)
714 		return;
715 
716 	dlyb->base = base_dlyb;
717 	if (of_device_is_compatible(np, "st,stm32mp25-sdmmc2"))
718 		dlyb->ops = &dlyb_tuning_mp25_ops;
719 	else
720 		dlyb->ops = &dlyb_tuning_mp15_ops;
721 
722 	host->variant_priv = dlyb;
723 	host->mmc_ops->execute_tuning = sdmmc_execute_tuning;
724 }
725