xref: /openbmc/linux/drivers/mmc/host/dw_mmc-exynos.c (revision 32981ea5)
1 /*
2  * Exynos Specific Extensions for Synopsys DW Multimedia Card Interface driver
3  *
4  * Copyright (C) 2012, Samsung Electronics Co., Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/clk.h>
15 #include <linux/mmc/host.h>
16 #include <linux/mmc/dw_mmc.h>
17 #include <linux/mmc/mmc.h>
18 #include <linux/of.h>
19 #include <linux/of_gpio.h>
20 #include <linux/slab.h>
21 
22 #include "dw_mmc.h"
23 #include "dw_mmc-pltfm.h"
24 #include "dw_mmc-exynos.h"
25 
26 /* Variations in Exynos specific dw-mshc controller */
27 enum dw_mci_exynos_type {
28 	DW_MCI_TYPE_EXYNOS4210,
29 	DW_MCI_TYPE_EXYNOS4412,
30 	DW_MCI_TYPE_EXYNOS5250,
31 	DW_MCI_TYPE_EXYNOS5420,
32 	DW_MCI_TYPE_EXYNOS5420_SMU,
33 	DW_MCI_TYPE_EXYNOS7,
34 	DW_MCI_TYPE_EXYNOS7_SMU,
35 };
36 
37 /* Exynos implementation specific driver private data */
38 struct dw_mci_exynos_priv_data {
39 	enum dw_mci_exynos_type		ctrl_type;
40 	u8				ciu_div;
41 	u32				sdr_timing;
42 	u32				ddr_timing;
43 	u32				hs400_timing;
44 	u32				tuned_sample;
45 	u32				cur_speed;
46 	u32				dqs_delay;
47 	u32				saved_dqs_en;
48 	u32				saved_strobe_ctrl;
49 };
50 
51 static struct dw_mci_exynos_compatible {
52 	char				*compatible;
53 	enum dw_mci_exynos_type		ctrl_type;
54 } exynos_compat[] = {
55 	{
56 		.compatible	= "samsung,exynos4210-dw-mshc",
57 		.ctrl_type	= DW_MCI_TYPE_EXYNOS4210,
58 	}, {
59 		.compatible	= "samsung,exynos4412-dw-mshc",
60 		.ctrl_type	= DW_MCI_TYPE_EXYNOS4412,
61 	}, {
62 		.compatible	= "samsung,exynos5250-dw-mshc",
63 		.ctrl_type	= DW_MCI_TYPE_EXYNOS5250,
64 	}, {
65 		.compatible	= "samsung,exynos5420-dw-mshc",
66 		.ctrl_type	= DW_MCI_TYPE_EXYNOS5420,
67 	}, {
68 		.compatible	= "samsung,exynos5420-dw-mshc-smu",
69 		.ctrl_type	= DW_MCI_TYPE_EXYNOS5420_SMU,
70 	}, {
71 		.compatible	= "samsung,exynos7-dw-mshc",
72 		.ctrl_type	= DW_MCI_TYPE_EXYNOS7,
73 	}, {
74 		.compatible	= "samsung,exynos7-dw-mshc-smu",
75 		.ctrl_type	= DW_MCI_TYPE_EXYNOS7_SMU,
76 	},
77 };
78 
79 static inline u8 dw_mci_exynos_get_ciu_div(struct dw_mci *host)
80 {
81 	struct dw_mci_exynos_priv_data *priv = host->priv;
82 
83 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
84 		return EXYNOS4412_FIXED_CIU_CLK_DIV;
85 	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
86 		return EXYNOS4210_FIXED_CIU_CLK_DIV;
87 	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
88 			priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
89 		return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL64)) + 1;
90 	else
91 		return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL)) + 1;
92 }
93 
94 static void dw_mci_exynos_config_smu(struct dw_mci *host)
95 {
96 	struct dw_mci_exynos_priv_data *priv = host->priv;
97 
98 	/*
99 	 * If Exynos is provided the Security management,
100 	 * set for non-ecryption mode at this time.
101 	 */
102 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5420_SMU ||
103 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU) {
104 		mci_writel(host, MPSBEGIN0, 0);
105 		mci_writel(host, MPSEND0, SDMMC_ENDING_SEC_NR_MAX);
106 		mci_writel(host, MPSCTRL0, SDMMC_MPSCTRL_SECURE_WRITE_BIT |
107 			   SDMMC_MPSCTRL_NON_SECURE_READ_BIT |
108 			   SDMMC_MPSCTRL_VALID |
109 			   SDMMC_MPSCTRL_NON_SECURE_WRITE_BIT);
110 	}
111 }
112 
113 static int dw_mci_exynos_priv_init(struct dw_mci *host)
114 {
115 	struct dw_mci_exynos_priv_data *priv = host->priv;
116 
117 	dw_mci_exynos_config_smu(host);
118 
119 	if (priv->ctrl_type >= DW_MCI_TYPE_EXYNOS5420) {
120 		priv->saved_strobe_ctrl = mci_readl(host, HS400_DLINE_CTRL);
121 		priv->saved_dqs_en = mci_readl(host, HS400_DQS_EN);
122 		priv->saved_dqs_en |= AXI_NON_BLOCKING_WR;
123 		mci_writel(host, HS400_DQS_EN, priv->saved_dqs_en);
124 		if (!priv->dqs_delay)
125 			priv->dqs_delay =
126 				DQS_CTRL_GET_RD_DELAY(priv->saved_strobe_ctrl);
127 	}
128 
129 	host->bus_hz /= (priv->ciu_div + 1);
130 
131 	return 0;
132 }
133 
134 static void dw_mci_exynos_set_clksel_timing(struct dw_mci *host, u32 timing)
135 {
136 	struct dw_mci_exynos_priv_data *priv = host->priv;
137 	u32 clksel;
138 
139 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
140 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
141 		clksel = mci_readl(host, CLKSEL64);
142 	else
143 		clksel = mci_readl(host, CLKSEL);
144 
145 	clksel = (clksel & ~SDMMC_CLKSEL_TIMING_MASK) | timing;
146 
147 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
148 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
149 		mci_writel(host, CLKSEL64, clksel);
150 	else
151 		mci_writel(host, CLKSEL, clksel);
152 
153 	/*
154 	 * Exynos4412 and Exynos5250 extends the use of CMD register with the
155 	 * use of bit 29 (which is reserved on standard MSHC controllers) for
156 	 * optionally bypassing the HOLD register for command and data. The
157 	 * HOLD register should be bypassed in case there is no phase shift
158 	 * applied on CMD/DATA that is sent to the card.
159 	 */
160 	if (!SDMMC_CLKSEL_GET_DRV_WD3(clksel))
161 		set_bit(DW_MMC_CARD_NO_USE_HOLD, &host->cur_slot->flags);
162 }
163 
164 #ifdef CONFIG_PM_SLEEP
165 static int dw_mci_exynos_suspend(struct device *dev)
166 {
167 	struct dw_mci *host = dev_get_drvdata(dev);
168 
169 	return dw_mci_suspend(host);
170 }
171 
172 static int dw_mci_exynos_resume(struct device *dev)
173 {
174 	struct dw_mci *host = dev_get_drvdata(dev);
175 
176 	dw_mci_exynos_config_smu(host);
177 	return dw_mci_resume(host);
178 }
179 
180 /**
181  * dw_mci_exynos_resume_noirq - Exynos-specific resume code
182  *
183  * On exynos5420 there is a silicon errata that will sometimes leave the
184  * WAKEUP_INT bit in the CLKSEL register asserted.  This bit is 1 to indicate
185  * that it fired and we can clear it by writing a 1 back.  Clear it to prevent
186  * interrupts from going off constantly.
187  *
188  * We run this code on all exynos variants because it doesn't hurt.
189  */
190 
191 static int dw_mci_exynos_resume_noirq(struct device *dev)
192 {
193 	struct dw_mci *host = dev_get_drvdata(dev);
194 	struct dw_mci_exynos_priv_data *priv = host->priv;
195 	u32 clksel;
196 
197 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
198 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
199 		clksel = mci_readl(host, CLKSEL64);
200 	else
201 		clksel = mci_readl(host, CLKSEL);
202 
203 	if (clksel & SDMMC_CLKSEL_WAKEUP_INT) {
204 		if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
205 			priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
206 			mci_writel(host, CLKSEL64, clksel);
207 		else
208 			mci_writel(host, CLKSEL, clksel);
209 	}
210 
211 	return 0;
212 }
213 #else
214 #define dw_mci_exynos_suspend		NULL
215 #define dw_mci_exynos_resume		NULL
216 #define dw_mci_exynos_resume_noirq	NULL
217 #endif /* CONFIG_PM_SLEEP */
218 
219 static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
220 {
221 	struct dw_mci_exynos_priv_data *priv = host->priv;
222 	u32 dqs, strobe;
223 
224 	/*
225 	 * Not supported to configure register
226 	 * related to HS400
227 	 */
228 	if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420)
229 		return;
230 
231 	dqs = priv->saved_dqs_en;
232 	strobe = priv->saved_strobe_ctrl;
233 
234 	if (timing == MMC_TIMING_MMC_HS400) {
235 		dqs |= DATA_STROBE_EN;
236 		strobe = DQS_CTRL_RD_DELAY(strobe, priv->dqs_delay);
237 	} else {
238 		dqs &= ~DATA_STROBE_EN;
239 	}
240 
241 	mci_writel(host, HS400_DQS_EN, dqs);
242 	mci_writel(host, HS400_DLINE_CTRL, strobe);
243 }
244 
245 static void dw_mci_exynos_adjust_clock(struct dw_mci *host, unsigned int wanted)
246 {
247 	struct dw_mci_exynos_priv_data *priv = host->priv;
248 	unsigned long actual;
249 	u8 div;
250 	int ret;
251 	/*
252 	 * Don't care if wanted clock is zero or
253 	 * ciu clock is unavailable
254 	 */
255 	if (!wanted || IS_ERR(host->ciu_clk))
256 		return;
257 
258 	/* Guaranteed minimum frequency for cclkin */
259 	if (wanted < EXYNOS_CCLKIN_MIN)
260 		wanted = EXYNOS_CCLKIN_MIN;
261 
262 	if (wanted == priv->cur_speed)
263 		return;
264 
265 	div = dw_mci_exynos_get_ciu_div(host);
266 	ret = clk_set_rate(host->ciu_clk, wanted * div);
267 	if (ret)
268 		dev_warn(host->dev,
269 			"failed to set clk-rate %u error: %d\n",
270 			wanted * div, ret);
271 	actual = clk_get_rate(host->ciu_clk);
272 	host->bus_hz = actual / div;
273 	priv->cur_speed = wanted;
274 	host->current_speed = 0;
275 }
276 
277 static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
278 {
279 	struct dw_mci_exynos_priv_data *priv = host->priv;
280 	unsigned int wanted = ios->clock;
281 	u32 timing = ios->timing, clksel;
282 
283 	switch (timing) {
284 	case MMC_TIMING_MMC_HS400:
285 		/* Update tuned sample timing */
286 		clksel = SDMMC_CLKSEL_UP_SAMPLE(
287 				priv->hs400_timing, priv->tuned_sample);
288 		wanted <<= 1;
289 		break;
290 	case MMC_TIMING_MMC_DDR52:
291 		clksel = priv->ddr_timing;
292 		/* Should be double rate for DDR mode */
293 		if (ios->bus_width == MMC_BUS_WIDTH_8)
294 			wanted <<= 1;
295 		break;
296 	default:
297 		clksel = priv->sdr_timing;
298 	}
299 
300 	/* Set clock timing for the requested speed mode*/
301 	dw_mci_exynos_set_clksel_timing(host, clksel);
302 
303 	/* Configure setting for HS400 */
304 	dw_mci_exynos_config_hs400(host, timing);
305 
306 	/* Configure clock rate */
307 	dw_mci_exynos_adjust_clock(host, wanted);
308 }
309 
310 static int dw_mci_exynos_parse_dt(struct dw_mci *host)
311 {
312 	struct dw_mci_exynos_priv_data *priv;
313 	struct device_node *np = host->dev->of_node;
314 	u32 timing[2];
315 	u32 div = 0;
316 	int idx;
317 	int ret;
318 
319 	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
320 	if (!priv)
321 		return -ENOMEM;
322 
323 	for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
324 		if (of_device_is_compatible(np, exynos_compat[idx].compatible))
325 			priv->ctrl_type = exynos_compat[idx].ctrl_type;
326 	}
327 
328 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
329 		priv->ciu_div = EXYNOS4412_FIXED_CIU_CLK_DIV - 1;
330 	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
331 		priv->ciu_div = EXYNOS4210_FIXED_CIU_CLK_DIV - 1;
332 	else {
333 		of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div);
334 		priv->ciu_div = div;
335 	}
336 
337 	ret = of_property_read_u32_array(np,
338 			"samsung,dw-mshc-sdr-timing", timing, 2);
339 	if (ret)
340 		return ret;
341 
342 	priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
343 
344 	ret = of_property_read_u32_array(np,
345 			"samsung,dw-mshc-ddr-timing", timing, 2);
346 	if (ret)
347 		return ret;
348 
349 	priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
350 
351 	ret = of_property_read_u32_array(np,
352 			"samsung,dw-mshc-hs400-timing", timing, 2);
353 	if (!ret && of_property_read_u32(np,
354 				"samsung,read-strobe-delay", &priv->dqs_delay))
355 		dev_dbg(host->dev,
356 			"read-strobe-delay is not found, assuming usage of default value\n");
357 
358 	priv->hs400_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1],
359 						HS400_FIXED_CIU_CLK_DIV);
360 	host->priv = priv;
361 	return 0;
362 }
363 
364 static inline u8 dw_mci_exynos_get_clksmpl(struct dw_mci *host)
365 {
366 	struct dw_mci_exynos_priv_data *priv = host->priv;
367 
368 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
369 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
370 		return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL64));
371 	else
372 		return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL));
373 }
374 
375 static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)
376 {
377 	u32 clksel;
378 	struct dw_mci_exynos_priv_data *priv = host->priv;
379 
380 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
381 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
382 		clksel = mci_readl(host, CLKSEL64);
383 	else
384 		clksel = mci_readl(host, CLKSEL);
385 	clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
386 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
387 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
388 		mci_writel(host, CLKSEL64, clksel);
389 	else
390 		mci_writel(host, CLKSEL, clksel);
391 }
392 
393 static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
394 {
395 	struct dw_mci_exynos_priv_data *priv = host->priv;
396 	u32 clksel;
397 	u8 sample;
398 
399 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
400 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
401 		clksel = mci_readl(host, CLKSEL64);
402 	else
403 		clksel = mci_readl(host, CLKSEL);
404 
405 	sample = (clksel + 1) & 0x7;
406 	clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
407 
408 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
409 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
410 		mci_writel(host, CLKSEL64, clksel);
411 	else
412 		mci_writel(host, CLKSEL, clksel);
413 
414 	return sample;
415 }
416 
417 static s8 dw_mci_exynos_get_best_clksmpl(u8 candiates)
418 {
419 	const u8 iter = 8;
420 	u8 __c;
421 	s8 i, loc = -1;
422 
423 	for (i = 0; i < iter; i++) {
424 		__c = ror8(candiates, i);
425 		if ((__c & 0xc7) == 0xc7) {
426 			loc = i;
427 			goto out;
428 		}
429 	}
430 
431 	for (i = 0; i < iter; i++) {
432 		__c = ror8(candiates, i);
433 		if ((__c & 0x83) == 0x83) {
434 			loc = i;
435 			goto out;
436 		}
437 	}
438 
439 out:
440 	return loc;
441 }
442 
443 static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
444 {
445 	struct dw_mci *host = slot->host;
446 	struct dw_mci_exynos_priv_data *priv = host->priv;
447 	struct mmc_host *mmc = slot->mmc;
448 	u8 start_smpl, smpl, candiates = 0;
449 	s8 found = -1;
450 	int ret = 0;
451 
452 	start_smpl = dw_mci_exynos_get_clksmpl(host);
453 
454 	do {
455 		mci_writel(host, TMOUT, ~0);
456 		smpl = dw_mci_exynos_move_next_clksmpl(host);
457 
458 		if (!mmc_send_tuning(mmc, opcode, NULL))
459 			candiates |= (1 << smpl);
460 
461 	} while (start_smpl != smpl);
462 
463 	found = dw_mci_exynos_get_best_clksmpl(candiates);
464 	if (found >= 0) {
465 		dw_mci_exynos_set_clksmpl(host, found);
466 		priv->tuned_sample = found;
467 	} else {
468 		ret = -EIO;
469 	}
470 
471 	return ret;
472 }
473 
474 static int dw_mci_exynos_prepare_hs400_tuning(struct dw_mci *host,
475 					struct mmc_ios *ios)
476 {
477 	struct dw_mci_exynos_priv_data *priv = host->priv;
478 
479 	dw_mci_exynos_set_clksel_timing(host, priv->hs400_timing);
480 	dw_mci_exynos_adjust_clock(host, (ios->clock) << 1);
481 
482 	return 0;
483 }
484 
485 /* Common capabilities of Exynos4/Exynos5 SoC */
486 static unsigned long exynos_dwmmc_caps[4] = {
487 	MMC_CAP_1_8V_DDR | MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
488 	MMC_CAP_CMD23,
489 	MMC_CAP_CMD23,
490 	MMC_CAP_CMD23,
491 };
492 
493 static const struct dw_mci_drv_data exynos_drv_data = {
494 	.caps			= exynos_dwmmc_caps,
495 	.init			= dw_mci_exynos_priv_init,
496 	.set_ios		= dw_mci_exynos_set_ios,
497 	.parse_dt		= dw_mci_exynos_parse_dt,
498 	.execute_tuning		= dw_mci_exynos_execute_tuning,
499 	.prepare_hs400_tuning	= dw_mci_exynos_prepare_hs400_tuning,
500 };
501 
502 static const struct of_device_id dw_mci_exynos_match[] = {
503 	{ .compatible = "samsung,exynos4412-dw-mshc",
504 			.data = &exynos_drv_data, },
505 	{ .compatible = "samsung,exynos5250-dw-mshc",
506 			.data = &exynos_drv_data, },
507 	{ .compatible = "samsung,exynos5420-dw-mshc",
508 			.data = &exynos_drv_data, },
509 	{ .compatible = "samsung,exynos5420-dw-mshc-smu",
510 			.data = &exynos_drv_data, },
511 	{ .compatible = "samsung,exynos7-dw-mshc",
512 			.data = &exynos_drv_data, },
513 	{ .compatible = "samsung,exynos7-dw-mshc-smu",
514 			.data = &exynos_drv_data, },
515 	{},
516 };
517 MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
518 
519 static int dw_mci_exynos_probe(struct platform_device *pdev)
520 {
521 	const struct dw_mci_drv_data *drv_data;
522 	const struct of_device_id *match;
523 
524 	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
525 	drv_data = match->data;
526 	return dw_mci_pltfm_register(pdev, drv_data);
527 }
528 
529 static const struct dev_pm_ops dw_mci_exynos_pmops = {
530 	SET_SYSTEM_SLEEP_PM_OPS(dw_mci_exynos_suspend, dw_mci_exynos_resume)
531 	.resume_noirq = dw_mci_exynos_resume_noirq,
532 	.thaw_noirq = dw_mci_exynos_resume_noirq,
533 	.restore_noirq = dw_mci_exynos_resume_noirq,
534 };
535 
536 static struct platform_driver dw_mci_exynos_pltfm_driver = {
537 	.probe		= dw_mci_exynos_probe,
538 	.remove		= dw_mci_pltfm_remove,
539 	.driver		= {
540 		.name		= "dwmmc_exynos",
541 		.of_match_table	= dw_mci_exynos_match,
542 		.pm		= &dw_mci_exynos_pmops,
543 	},
544 };
545 
546 module_platform_driver(dw_mci_exynos_pltfm_driver);
547 
548 MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
549 MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
550 MODULE_LICENSE("GPL v2");
551 MODULE_ALIAS("platform:dwmmc_exynos");
552