xref: /openbmc/linux/drivers/mmc/host/dw_mmc-exynos.c (revision 941a659f)
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) && host->cur_slot)
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 		if (timing == MMC_TIMING_MMC_HS400)
230 			dev_warn(host->dev,
231 				 "cannot configure HS400, unsupported chipset\n");
232 		return;
233 	}
234 
235 	dqs = priv->saved_dqs_en;
236 	strobe = priv->saved_strobe_ctrl;
237 
238 	if (timing == MMC_TIMING_MMC_HS400) {
239 		dqs |= DATA_STROBE_EN;
240 		strobe = DQS_CTRL_RD_DELAY(strobe, priv->dqs_delay);
241 	} else {
242 		dqs &= ~DATA_STROBE_EN;
243 	}
244 
245 	mci_writel(host, HS400_DQS_EN, dqs);
246 	mci_writel(host, HS400_DLINE_CTRL, strobe);
247 }
248 
249 static void dw_mci_exynos_adjust_clock(struct dw_mci *host, unsigned int wanted)
250 {
251 	struct dw_mci_exynos_priv_data *priv = host->priv;
252 	unsigned long actual;
253 	u8 div;
254 	int ret;
255 	/*
256 	 * Don't care if wanted clock is zero or
257 	 * ciu clock is unavailable
258 	 */
259 	if (!wanted || IS_ERR(host->ciu_clk))
260 		return;
261 
262 	/* Guaranteed minimum frequency for cclkin */
263 	if (wanted < EXYNOS_CCLKIN_MIN)
264 		wanted = EXYNOS_CCLKIN_MIN;
265 
266 	if (wanted == priv->cur_speed)
267 		return;
268 
269 	div = dw_mci_exynos_get_ciu_div(host);
270 	ret = clk_set_rate(host->ciu_clk, wanted * div);
271 	if (ret)
272 		dev_warn(host->dev,
273 			"failed to set clk-rate %u error: %d\n",
274 			wanted * div, ret);
275 	actual = clk_get_rate(host->ciu_clk);
276 	host->bus_hz = actual / div;
277 	priv->cur_speed = wanted;
278 	host->current_speed = 0;
279 }
280 
281 static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
282 {
283 	struct dw_mci_exynos_priv_data *priv = host->priv;
284 	unsigned int wanted = ios->clock;
285 	u32 timing = ios->timing, clksel;
286 
287 	switch (timing) {
288 	case MMC_TIMING_MMC_HS400:
289 		/* Update tuned sample timing */
290 		clksel = SDMMC_CLKSEL_UP_SAMPLE(
291 				priv->hs400_timing, priv->tuned_sample);
292 		wanted <<= 1;
293 		break;
294 	case MMC_TIMING_MMC_DDR52:
295 		clksel = priv->ddr_timing;
296 		/* Should be double rate for DDR mode */
297 		if (ios->bus_width == MMC_BUS_WIDTH_8)
298 			wanted <<= 1;
299 		break;
300 	default:
301 		clksel = priv->sdr_timing;
302 	}
303 
304 	/* Set clock timing for the requested speed mode*/
305 	dw_mci_exynos_set_clksel_timing(host, clksel);
306 
307 	/* Configure setting for HS400 */
308 	dw_mci_exynos_config_hs400(host, timing);
309 
310 	/* Configure clock rate */
311 	dw_mci_exynos_adjust_clock(host, wanted);
312 }
313 
314 static int dw_mci_exynos_parse_dt(struct dw_mci *host)
315 {
316 	struct dw_mci_exynos_priv_data *priv;
317 	struct device_node *np = host->dev->of_node;
318 	u32 timing[2];
319 	u32 div = 0;
320 	int idx;
321 	int ret;
322 
323 	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
324 	if (!priv)
325 		return -ENOMEM;
326 
327 	for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
328 		if (of_device_is_compatible(np, exynos_compat[idx].compatible))
329 			priv->ctrl_type = exynos_compat[idx].ctrl_type;
330 	}
331 
332 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
333 		priv->ciu_div = EXYNOS4412_FIXED_CIU_CLK_DIV - 1;
334 	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
335 		priv->ciu_div = EXYNOS4210_FIXED_CIU_CLK_DIV - 1;
336 	else {
337 		of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div);
338 		priv->ciu_div = div;
339 	}
340 
341 	ret = of_property_read_u32_array(np,
342 			"samsung,dw-mshc-sdr-timing", timing, 2);
343 	if (ret)
344 		return ret;
345 
346 	priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
347 
348 	ret = of_property_read_u32_array(np,
349 			"samsung,dw-mshc-ddr-timing", timing, 2);
350 	if (ret)
351 		return ret;
352 
353 	priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
354 
355 	ret = of_property_read_u32_array(np,
356 			"samsung,dw-mshc-hs400-timing", timing, 2);
357 	if (!ret && of_property_read_u32(np,
358 				"samsung,read-strobe-delay", &priv->dqs_delay))
359 		dev_dbg(host->dev,
360 			"read-strobe-delay is not found, assuming usage of default value\n");
361 
362 	priv->hs400_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1],
363 						HS400_FIXED_CIU_CLK_DIV);
364 	host->priv = priv;
365 	return 0;
366 }
367 
368 static inline u8 dw_mci_exynos_get_clksmpl(struct dw_mci *host)
369 {
370 	struct dw_mci_exynos_priv_data *priv = host->priv;
371 
372 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
373 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
374 		return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL64));
375 	else
376 		return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL));
377 }
378 
379 static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)
380 {
381 	u32 clksel;
382 	struct dw_mci_exynos_priv_data *priv = host->priv;
383 
384 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
385 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
386 		clksel = mci_readl(host, CLKSEL64);
387 	else
388 		clksel = mci_readl(host, CLKSEL);
389 	clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
390 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
391 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
392 		mci_writel(host, CLKSEL64, clksel);
393 	else
394 		mci_writel(host, CLKSEL, clksel);
395 }
396 
397 static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
398 {
399 	struct dw_mci_exynos_priv_data *priv = host->priv;
400 	u32 clksel;
401 	u8 sample;
402 
403 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
404 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
405 		clksel = mci_readl(host, CLKSEL64);
406 	else
407 		clksel = mci_readl(host, CLKSEL);
408 
409 	sample = (clksel + 1) & 0x7;
410 	clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
411 
412 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
413 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
414 		mci_writel(host, CLKSEL64, clksel);
415 	else
416 		mci_writel(host, CLKSEL, clksel);
417 
418 	return sample;
419 }
420 
421 static s8 dw_mci_exynos_get_best_clksmpl(u8 candiates)
422 {
423 	const u8 iter = 8;
424 	u8 __c;
425 	s8 i, loc = -1;
426 
427 	for (i = 0; i < iter; i++) {
428 		__c = ror8(candiates, i);
429 		if ((__c & 0xc7) == 0xc7) {
430 			loc = i;
431 			goto out;
432 		}
433 	}
434 
435 	for (i = 0; i < iter; i++) {
436 		__c = ror8(candiates, i);
437 		if ((__c & 0x83) == 0x83) {
438 			loc = i;
439 			goto out;
440 		}
441 	}
442 
443 out:
444 	return loc;
445 }
446 
447 static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
448 {
449 	struct dw_mci *host = slot->host;
450 	struct dw_mci_exynos_priv_data *priv = host->priv;
451 	struct mmc_host *mmc = slot->mmc;
452 	u8 start_smpl, smpl, candiates = 0;
453 	s8 found = -1;
454 	int ret = 0;
455 
456 	start_smpl = dw_mci_exynos_get_clksmpl(host);
457 
458 	do {
459 		mci_writel(host, TMOUT, ~0);
460 		smpl = dw_mci_exynos_move_next_clksmpl(host);
461 
462 		if (!mmc_send_tuning(mmc, opcode, NULL))
463 			candiates |= (1 << smpl);
464 
465 	} while (start_smpl != smpl);
466 
467 	found = dw_mci_exynos_get_best_clksmpl(candiates);
468 	if (found >= 0) {
469 		dw_mci_exynos_set_clksmpl(host, found);
470 		priv->tuned_sample = found;
471 	} else {
472 		ret = -EIO;
473 	}
474 
475 	return ret;
476 }
477 
478 static int dw_mci_exynos_prepare_hs400_tuning(struct dw_mci *host,
479 					struct mmc_ios *ios)
480 {
481 	struct dw_mci_exynos_priv_data *priv = host->priv;
482 
483 	dw_mci_exynos_set_clksel_timing(host, priv->hs400_timing);
484 	dw_mci_exynos_adjust_clock(host, (ios->clock) << 1);
485 
486 	return 0;
487 }
488 
489 /* Common capabilities of Exynos4/Exynos5 SoC */
490 static unsigned long exynos_dwmmc_caps[4] = {
491 	MMC_CAP_1_8V_DDR | MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
492 	MMC_CAP_CMD23,
493 	MMC_CAP_CMD23,
494 	MMC_CAP_CMD23,
495 };
496 
497 static const struct dw_mci_drv_data exynos_drv_data = {
498 	.caps			= exynos_dwmmc_caps,
499 	.init			= dw_mci_exynos_priv_init,
500 	.set_ios		= dw_mci_exynos_set_ios,
501 	.parse_dt		= dw_mci_exynos_parse_dt,
502 	.execute_tuning		= dw_mci_exynos_execute_tuning,
503 	.prepare_hs400_tuning	= dw_mci_exynos_prepare_hs400_tuning,
504 };
505 
506 static const struct of_device_id dw_mci_exynos_match[] = {
507 	{ .compatible = "samsung,exynos4412-dw-mshc",
508 			.data = &exynos_drv_data, },
509 	{ .compatible = "samsung,exynos5250-dw-mshc",
510 			.data = &exynos_drv_data, },
511 	{ .compatible = "samsung,exynos5420-dw-mshc",
512 			.data = &exynos_drv_data, },
513 	{ .compatible = "samsung,exynos5420-dw-mshc-smu",
514 			.data = &exynos_drv_data, },
515 	{ .compatible = "samsung,exynos7-dw-mshc",
516 			.data = &exynos_drv_data, },
517 	{ .compatible = "samsung,exynos7-dw-mshc-smu",
518 			.data = &exynos_drv_data, },
519 	{},
520 };
521 MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
522 
523 static int dw_mci_exynos_probe(struct platform_device *pdev)
524 {
525 	const struct dw_mci_drv_data *drv_data;
526 	const struct of_device_id *match;
527 
528 	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
529 	drv_data = match->data;
530 	return dw_mci_pltfm_register(pdev, drv_data);
531 }
532 
533 static const struct dev_pm_ops dw_mci_exynos_pmops = {
534 	SET_SYSTEM_SLEEP_PM_OPS(dw_mci_exynos_suspend, dw_mci_exynos_resume)
535 	.resume_noirq = dw_mci_exynos_resume_noirq,
536 	.thaw_noirq = dw_mci_exynos_resume_noirq,
537 	.restore_noirq = dw_mci_exynos_resume_noirq,
538 };
539 
540 static struct platform_driver dw_mci_exynos_pltfm_driver = {
541 	.probe		= dw_mci_exynos_probe,
542 	.remove		= dw_mci_pltfm_remove,
543 	.driver		= {
544 		.name		= "dwmmc_exynos",
545 		.of_match_table	= dw_mci_exynos_match,
546 		.pm		= &dw_mci_exynos_pmops,
547 	},
548 };
549 
550 module_platform_driver(dw_mci_exynos_pltfm_driver);
551 
552 MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
553 MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
554 MODULE_LICENSE("GPL v2");
555 MODULE_ALIAS("platform:dwmmc_exynos");
556