xref: /openbmc/linux/drivers/mmc/host/dw_mmc-exynos.c (revision cf5237ef)
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/pm_runtime.h>
21 #include <linux/slab.h>
22 
23 #include "dw_mmc.h"
24 #include "dw_mmc-pltfm.h"
25 #include "dw_mmc-exynos.h"
26 
27 /* Variations in Exynos specific dw-mshc controller */
28 enum dw_mci_exynos_type {
29 	DW_MCI_TYPE_EXYNOS4210,
30 	DW_MCI_TYPE_EXYNOS4412,
31 	DW_MCI_TYPE_EXYNOS5250,
32 	DW_MCI_TYPE_EXYNOS5420,
33 	DW_MCI_TYPE_EXYNOS5420_SMU,
34 	DW_MCI_TYPE_EXYNOS7,
35 	DW_MCI_TYPE_EXYNOS7_SMU,
36 };
37 
38 /* Exynos implementation specific driver private data */
39 struct dw_mci_exynos_priv_data {
40 	enum dw_mci_exynos_type		ctrl_type;
41 	u8				ciu_div;
42 	u32				sdr_timing;
43 	u32				ddr_timing;
44 	u32				hs400_timing;
45 	u32				tuned_sample;
46 	u32				cur_speed;
47 	u32				dqs_delay;
48 	u32				saved_dqs_en;
49 	u32				saved_strobe_ctrl;
50 };
51 
52 static struct dw_mci_exynos_compatible {
53 	char				*compatible;
54 	enum dw_mci_exynos_type		ctrl_type;
55 } exynos_compat[] = {
56 	{
57 		.compatible	= "samsung,exynos4210-dw-mshc",
58 		.ctrl_type	= DW_MCI_TYPE_EXYNOS4210,
59 	}, {
60 		.compatible	= "samsung,exynos4412-dw-mshc",
61 		.ctrl_type	= DW_MCI_TYPE_EXYNOS4412,
62 	}, {
63 		.compatible	= "samsung,exynos5250-dw-mshc",
64 		.ctrl_type	= DW_MCI_TYPE_EXYNOS5250,
65 	}, {
66 		.compatible	= "samsung,exynos5420-dw-mshc",
67 		.ctrl_type	= DW_MCI_TYPE_EXYNOS5420,
68 	}, {
69 		.compatible	= "samsung,exynos5420-dw-mshc-smu",
70 		.ctrl_type	= DW_MCI_TYPE_EXYNOS5420_SMU,
71 	}, {
72 		.compatible	= "samsung,exynos7-dw-mshc",
73 		.ctrl_type	= DW_MCI_TYPE_EXYNOS7,
74 	}, {
75 		.compatible	= "samsung,exynos7-dw-mshc-smu",
76 		.ctrl_type	= DW_MCI_TYPE_EXYNOS7_SMU,
77 	},
78 };
79 
80 static inline u8 dw_mci_exynos_get_ciu_div(struct dw_mci *host)
81 {
82 	struct dw_mci_exynos_priv_data *priv = host->priv;
83 
84 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
85 		return EXYNOS4412_FIXED_CIU_CLK_DIV;
86 	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
87 		return EXYNOS4210_FIXED_CIU_CLK_DIV;
88 	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
89 			priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
90 		return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL64)) + 1;
91 	else
92 		return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL)) + 1;
93 }
94 
95 static void dw_mci_exynos_config_smu(struct dw_mci *host)
96 {
97 	struct dw_mci_exynos_priv_data *priv = host->priv;
98 
99 	/*
100 	 * If Exynos is provided the Security management,
101 	 * set for non-ecryption mode at this time.
102 	 */
103 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5420_SMU ||
104 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU) {
105 		mci_writel(host, MPSBEGIN0, 0);
106 		mci_writel(host, MPSEND0, SDMMC_ENDING_SEC_NR_MAX);
107 		mci_writel(host, MPSCTRL0, SDMMC_MPSCTRL_SECURE_WRITE_BIT |
108 			   SDMMC_MPSCTRL_NON_SECURE_READ_BIT |
109 			   SDMMC_MPSCTRL_VALID |
110 			   SDMMC_MPSCTRL_NON_SECURE_WRITE_BIT);
111 	}
112 }
113 
114 static int dw_mci_exynos_priv_init(struct dw_mci *host)
115 {
116 	struct dw_mci_exynos_priv_data *priv = host->priv;
117 
118 	dw_mci_exynos_config_smu(host);
119 
120 	if (priv->ctrl_type >= DW_MCI_TYPE_EXYNOS5420) {
121 		priv->saved_strobe_ctrl = mci_readl(host, HS400_DLINE_CTRL);
122 		priv->saved_dqs_en = mci_readl(host, HS400_DQS_EN);
123 		priv->saved_dqs_en |= AXI_NON_BLOCKING_WR;
124 		mci_writel(host, HS400_DQS_EN, priv->saved_dqs_en);
125 		if (!priv->dqs_delay)
126 			priv->dqs_delay =
127 				DQS_CTRL_GET_RD_DELAY(priv->saved_strobe_ctrl);
128 	}
129 
130 	host->bus_hz /= (priv->ciu_div + 1);
131 
132 	return 0;
133 }
134 
135 static void dw_mci_exynos_set_clksel_timing(struct dw_mci *host, u32 timing)
136 {
137 	struct dw_mci_exynos_priv_data *priv = host->priv;
138 	u32 clksel;
139 
140 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
141 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
142 		clksel = mci_readl(host, CLKSEL64);
143 	else
144 		clksel = mci_readl(host, CLKSEL);
145 
146 	clksel = (clksel & ~SDMMC_CLKSEL_TIMING_MASK) | timing;
147 
148 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
149 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
150 		mci_writel(host, CLKSEL64, clksel);
151 	else
152 		mci_writel(host, CLKSEL, clksel);
153 
154 	/*
155 	 * Exynos4412 and Exynos5250 extends the use of CMD register with the
156 	 * use of bit 29 (which is reserved on standard MSHC controllers) for
157 	 * optionally bypassing the HOLD register for command and data. The
158 	 * HOLD register should be bypassed in case there is no phase shift
159 	 * applied on CMD/DATA that is sent to the card.
160 	 */
161 	if (!SDMMC_CLKSEL_GET_DRV_WD3(clksel) && host->cur_slot)
162 		set_bit(DW_MMC_CARD_NO_USE_HOLD, &host->cur_slot->flags);
163 }
164 
165 #ifdef CONFIG_PM
166 static int dw_mci_exynos_runtime_resume(struct device *dev)
167 {
168 	struct dw_mci *host = dev_get_drvdata(dev);
169 
170 	dw_mci_exynos_config_smu(host);
171 	return dw_mci_runtime_resume(dev);
172 }
173 
174 /**
175  * dw_mci_exynos_resume_noirq - Exynos-specific resume code
176  *
177  * On exynos5420 there is a silicon errata that will sometimes leave the
178  * WAKEUP_INT bit in the CLKSEL register asserted.  This bit is 1 to indicate
179  * that it fired and we can clear it by writing a 1 back.  Clear it to prevent
180  * interrupts from going off constantly.
181  *
182  * We run this code on all exynos variants because it doesn't hurt.
183  */
184 
185 static int dw_mci_exynos_resume_noirq(struct device *dev)
186 {
187 	struct dw_mci *host = dev_get_drvdata(dev);
188 	struct dw_mci_exynos_priv_data *priv = host->priv;
189 	u32 clksel;
190 
191 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
192 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
193 		clksel = mci_readl(host, CLKSEL64);
194 	else
195 		clksel = mci_readl(host, CLKSEL);
196 
197 	if (clksel & SDMMC_CLKSEL_WAKEUP_INT) {
198 		if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
199 			priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
200 			mci_writel(host, CLKSEL64, clksel);
201 		else
202 			mci_writel(host, CLKSEL, clksel);
203 	}
204 
205 	return 0;
206 }
207 #else
208 #define dw_mci_exynos_resume_noirq	NULL
209 #endif /* CONFIG_PM */
210 
211 static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
212 {
213 	struct dw_mci_exynos_priv_data *priv = host->priv;
214 	u32 dqs, strobe;
215 
216 	/*
217 	 * Not supported to configure register
218 	 * related to HS400
219 	 */
220 	if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420) {
221 		if (timing == MMC_TIMING_MMC_HS400)
222 			dev_warn(host->dev,
223 				 "cannot configure HS400, unsupported chipset\n");
224 		return;
225 	}
226 
227 	dqs = priv->saved_dqs_en;
228 	strobe = priv->saved_strobe_ctrl;
229 
230 	if (timing == MMC_TIMING_MMC_HS400) {
231 		dqs |= DATA_STROBE_EN;
232 		strobe = DQS_CTRL_RD_DELAY(strobe, priv->dqs_delay);
233 	} else {
234 		dqs &= ~DATA_STROBE_EN;
235 	}
236 
237 	mci_writel(host, HS400_DQS_EN, dqs);
238 	mci_writel(host, HS400_DLINE_CTRL, strobe);
239 }
240 
241 static void dw_mci_exynos_adjust_clock(struct dw_mci *host, unsigned int wanted)
242 {
243 	struct dw_mci_exynos_priv_data *priv = host->priv;
244 	unsigned long actual;
245 	u8 div;
246 	int ret;
247 	/*
248 	 * Don't care if wanted clock is zero or
249 	 * ciu clock is unavailable
250 	 */
251 	if (!wanted || IS_ERR(host->ciu_clk))
252 		return;
253 
254 	/* Guaranteed minimum frequency for cclkin */
255 	if (wanted < EXYNOS_CCLKIN_MIN)
256 		wanted = EXYNOS_CCLKIN_MIN;
257 
258 	if (wanted == priv->cur_speed)
259 		return;
260 
261 	div = dw_mci_exynos_get_ciu_div(host);
262 	ret = clk_set_rate(host->ciu_clk, wanted * div);
263 	if (ret)
264 		dev_warn(host->dev,
265 			"failed to set clk-rate %u error: %d\n",
266 			wanted * div, ret);
267 	actual = clk_get_rate(host->ciu_clk);
268 	host->bus_hz = actual / div;
269 	priv->cur_speed = wanted;
270 	host->current_speed = 0;
271 }
272 
273 static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
274 {
275 	struct dw_mci_exynos_priv_data *priv = host->priv;
276 	unsigned int wanted = ios->clock;
277 	u32 timing = ios->timing, clksel;
278 
279 	switch (timing) {
280 	case MMC_TIMING_MMC_HS400:
281 		/* Update tuned sample timing */
282 		clksel = SDMMC_CLKSEL_UP_SAMPLE(
283 				priv->hs400_timing, priv->tuned_sample);
284 		wanted <<= 1;
285 		break;
286 	case MMC_TIMING_MMC_DDR52:
287 		clksel = priv->ddr_timing;
288 		/* Should be double rate for DDR mode */
289 		if (ios->bus_width == MMC_BUS_WIDTH_8)
290 			wanted <<= 1;
291 		break;
292 	default:
293 		clksel = priv->sdr_timing;
294 	}
295 
296 	/* Set clock timing for the requested speed mode*/
297 	dw_mci_exynos_set_clksel_timing(host, clksel);
298 
299 	/* Configure setting for HS400 */
300 	dw_mci_exynos_config_hs400(host, timing);
301 
302 	/* Configure clock rate */
303 	dw_mci_exynos_adjust_clock(host, wanted);
304 }
305 
306 static int dw_mci_exynos_parse_dt(struct dw_mci *host)
307 {
308 	struct dw_mci_exynos_priv_data *priv;
309 	struct device_node *np = host->dev->of_node;
310 	u32 timing[2];
311 	u32 div = 0;
312 	int idx;
313 	int ret;
314 
315 	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
316 	if (!priv)
317 		return -ENOMEM;
318 
319 	for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
320 		if (of_device_is_compatible(np, exynos_compat[idx].compatible))
321 			priv->ctrl_type = exynos_compat[idx].ctrl_type;
322 	}
323 
324 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
325 		priv->ciu_div = EXYNOS4412_FIXED_CIU_CLK_DIV - 1;
326 	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
327 		priv->ciu_div = EXYNOS4210_FIXED_CIU_CLK_DIV - 1;
328 	else {
329 		of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div);
330 		priv->ciu_div = div;
331 	}
332 
333 	ret = of_property_read_u32_array(np,
334 			"samsung,dw-mshc-sdr-timing", timing, 2);
335 	if (ret)
336 		return ret;
337 
338 	priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
339 
340 	ret = of_property_read_u32_array(np,
341 			"samsung,dw-mshc-ddr-timing", timing, 2);
342 	if (ret)
343 		return ret;
344 
345 	priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
346 
347 	ret = of_property_read_u32_array(np,
348 			"samsung,dw-mshc-hs400-timing", timing, 2);
349 	if (!ret && of_property_read_u32(np,
350 				"samsung,read-strobe-delay", &priv->dqs_delay))
351 		dev_dbg(host->dev,
352 			"read-strobe-delay is not found, assuming usage of default value\n");
353 
354 	priv->hs400_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1],
355 						HS400_FIXED_CIU_CLK_DIV);
356 	host->priv = priv;
357 	return 0;
358 }
359 
360 static inline u8 dw_mci_exynos_get_clksmpl(struct dw_mci *host)
361 {
362 	struct dw_mci_exynos_priv_data *priv = host->priv;
363 
364 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
365 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
366 		return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL64));
367 	else
368 		return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL));
369 }
370 
371 static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)
372 {
373 	u32 clksel;
374 	struct dw_mci_exynos_priv_data *priv = host->priv;
375 
376 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
377 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
378 		clksel = mci_readl(host, CLKSEL64);
379 	else
380 		clksel = mci_readl(host, CLKSEL);
381 	clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
382 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
383 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
384 		mci_writel(host, CLKSEL64, clksel);
385 	else
386 		mci_writel(host, CLKSEL, clksel);
387 }
388 
389 static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
390 {
391 	struct dw_mci_exynos_priv_data *priv = host->priv;
392 	u32 clksel;
393 	u8 sample;
394 
395 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
396 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
397 		clksel = mci_readl(host, CLKSEL64);
398 	else
399 		clksel = mci_readl(host, CLKSEL);
400 
401 	sample = (clksel + 1) & 0x7;
402 	clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
403 
404 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
405 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
406 		mci_writel(host, CLKSEL64, clksel);
407 	else
408 		mci_writel(host, CLKSEL, clksel);
409 
410 	return sample;
411 }
412 
413 static s8 dw_mci_exynos_get_best_clksmpl(u8 candiates)
414 {
415 	const u8 iter = 8;
416 	u8 __c;
417 	s8 i, loc = -1;
418 
419 	for (i = 0; i < iter; i++) {
420 		__c = ror8(candiates, i);
421 		if ((__c & 0xc7) == 0xc7) {
422 			loc = i;
423 			goto out;
424 		}
425 	}
426 
427 	for (i = 0; i < iter; i++) {
428 		__c = ror8(candiates, i);
429 		if ((__c & 0x83) == 0x83) {
430 			loc = i;
431 			goto out;
432 		}
433 	}
434 
435 out:
436 	return loc;
437 }
438 
439 static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
440 {
441 	struct dw_mci *host = slot->host;
442 	struct dw_mci_exynos_priv_data *priv = host->priv;
443 	struct mmc_host *mmc = slot->mmc;
444 	u8 start_smpl, smpl, candiates = 0;
445 	s8 found = -1;
446 	int ret = 0;
447 
448 	start_smpl = dw_mci_exynos_get_clksmpl(host);
449 
450 	do {
451 		mci_writel(host, TMOUT, ~0);
452 		smpl = dw_mci_exynos_move_next_clksmpl(host);
453 
454 		if (!mmc_send_tuning(mmc, opcode, NULL))
455 			candiates |= (1 << smpl);
456 
457 	} while (start_smpl != smpl);
458 
459 	found = dw_mci_exynos_get_best_clksmpl(candiates);
460 	if (found >= 0) {
461 		dw_mci_exynos_set_clksmpl(host, found);
462 		priv->tuned_sample = found;
463 	} else {
464 		ret = -EIO;
465 	}
466 
467 	return ret;
468 }
469 
470 static int dw_mci_exynos_prepare_hs400_tuning(struct dw_mci *host,
471 					struct mmc_ios *ios)
472 {
473 	struct dw_mci_exynos_priv_data *priv = host->priv;
474 
475 	dw_mci_exynos_set_clksel_timing(host, priv->hs400_timing);
476 	dw_mci_exynos_adjust_clock(host, (ios->clock) << 1);
477 
478 	return 0;
479 }
480 
481 /* Common capabilities of Exynos4/Exynos5 SoC */
482 static unsigned long exynos_dwmmc_caps[4] = {
483 	MMC_CAP_1_8V_DDR | MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
484 	MMC_CAP_CMD23,
485 	MMC_CAP_CMD23,
486 	MMC_CAP_CMD23,
487 };
488 
489 static const struct dw_mci_drv_data exynos_drv_data = {
490 	.caps			= exynos_dwmmc_caps,
491 	.init			= dw_mci_exynos_priv_init,
492 	.set_ios		= dw_mci_exynos_set_ios,
493 	.parse_dt		= dw_mci_exynos_parse_dt,
494 	.execute_tuning		= dw_mci_exynos_execute_tuning,
495 	.prepare_hs400_tuning	= dw_mci_exynos_prepare_hs400_tuning,
496 };
497 
498 static const struct of_device_id dw_mci_exynos_match[] = {
499 	{ .compatible = "samsung,exynos4412-dw-mshc",
500 			.data = &exynos_drv_data, },
501 	{ .compatible = "samsung,exynos5250-dw-mshc",
502 			.data = &exynos_drv_data, },
503 	{ .compatible = "samsung,exynos5420-dw-mshc",
504 			.data = &exynos_drv_data, },
505 	{ .compatible = "samsung,exynos5420-dw-mshc-smu",
506 			.data = &exynos_drv_data, },
507 	{ .compatible = "samsung,exynos7-dw-mshc",
508 			.data = &exynos_drv_data, },
509 	{ .compatible = "samsung,exynos7-dw-mshc-smu",
510 			.data = &exynos_drv_data, },
511 	{},
512 };
513 MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
514 
515 static int dw_mci_exynos_probe(struct platform_device *pdev)
516 {
517 	const struct dw_mci_drv_data *drv_data;
518 	const struct of_device_id *match;
519 
520 	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
521 	drv_data = match->data;
522 	return dw_mci_pltfm_register(pdev, drv_data);
523 }
524 
525 static const struct dev_pm_ops dw_mci_exynos_pmops = {
526 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
527 				pm_runtime_force_resume)
528 	SET_RUNTIME_PM_OPS(dw_mci_runtime_suspend,
529 			   dw_mci_exynos_runtime_resume,
530 			   NULL)
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