xref: /openbmc/linux/drivers/mmc/host/dw_mmc-exynos.c (revision 9cfc5c90)
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 int dw_mci_exynos_priv_init(struct dw_mci *host)
95 {
96 	struct dw_mci_exynos_priv_data *priv = host->priv;
97 
98 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5420_SMU ||
99 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU) {
100 		mci_writel(host, MPSBEGIN0, 0);
101 		mci_writel(host, MPSEND0, SDMMC_ENDING_SEC_NR_MAX);
102 		mci_writel(host, MPSCTRL0, SDMMC_MPSCTRL_SECURE_WRITE_BIT |
103 			   SDMMC_MPSCTRL_NON_SECURE_READ_BIT |
104 			   SDMMC_MPSCTRL_VALID |
105 			   SDMMC_MPSCTRL_NON_SECURE_WRITE_BIT);
106 	}
107 
108 	if (priv->ctrl_type >= DW_MCI_TYPE_EXYNOS5420) {
109 		priv->saved_strobe_ctrl = mci_readl(host, HS400_DLINE_CTRL);
110 		priv->saved_dqs_en = mci_readl(host, HS400_DQS_EN);
111 		priv->saved_dqs_en |= AXI_NON_BLOCKING_WR;
112 		mci_writel(host, HS400_DQS_EN, priv->saved_dqs_en);
113 		if (!priv->dqs_delay)
114 			priv->dqs_delay =
115 				DQS_CTRL_GET_RD_DELAY(priv->saved_strobe_ctrl);
116 	}
117 
118 	return 0;
119 }
120 
121 static int dw_mci_exynos_setup_clock(struct dw_mci *host)
122 {
123 	struct dw_mci_exynos_priv_data *priv = host->priv;
124 
125 	host->bus_hz /= (priv->ciu_div + 1);
126 
127 	return 0;
128 }
129 
130 static void dw_mci_exynos_set_clksel_timing(struct dw_mci *host, u32 timing)
131 {
132 	struct dw_mci_exynos_priv_data *priv = host->priv;
133 	u32 clksel;
134 
135 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
136 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
137 		clksel = mci_readl(host, CLKSEL64);
138 	else
139 		clksel = mci_readl(host, CLKSEL);
140 
141 	clksel = (clksel & ~SDMMC_CLKSEL_TIMING_MASK) | timing;
142 
143 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
144 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
145 		mci_writel(host, CLKSEL64, clksel);
146 	else
147 		mci_writel(host, CLKSEL, clksel);
148 }
149 
150 #ifdef CONFIG_PM_SLEEP
151 static int dw_mci_exynos_suspend(struct device *dev)
152 {
153 	struct dw_mci *host = dev_get_drvdata(dev);
154 
155 	return dw_mci_suspend(host);
156 }
157 
158 static int dw_mci_exynos_resume(struct device *dev)
159 {
160 	struct dw_mci *host = dev_get_drvdata(dev);
161 
162 	dw_mci_exynos_priv_init(host);
163 	return dw_mci_resume(host);
164 }
165 
166 /**
167  * dw_mci_exynos_resume_noirq - Exynos-specific resume code
168  *
169  * On exynos5420 there is a silicon errata that will sometimes leave the
170  * WAKEUP_INT bit in the CLKSEL register asserted.  This bit is 1 to indicate
171  * that it fired and we can clear it by writing a 1 back.  Clear it to prevent
172  * interrupts from going off constantly.
173  *
174  * We run this code on all exynos variants because it doesn't hurt.
175  */
176 
177 static int dw_mci_exynos_resume_noirq(struct device *dev)
178 {
179 	struct dw_mci *host = dev_get_drvdata(dev);
180 	struct dw_mci_exynos_priv_data *priv = host->priv;
181 	u32 clksel;
182 
183 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
184 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
185 		clksel = mci_readl(host, CLKSEL64);
186 	else
187 		clksel = mci_readl(host, CLKSEL);
188 
189 	if (clksel & SDMMC_CLKSEL_WAKEUP_INT) {
190 		if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
191 			priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
192 			mci_writel(host, CLKSEL64, clksel);
193 		else
194 			mci_writel(host, CLKSEL, clksel);
195 	}
196 
197 	return 0;
198 }
199 #else
200 #define dw_mci_exynos_suspend		NULL
201 #define dw_mci_exynos_resume		NULL
202 #define dw_mci_exynos_resume_noirq	NULL
203 #endif /* CONFIG_PM_SLEEP */
204 
205 static void dw_mci_exynos_prepare_command(struct dw_mci *host, u32 *cmdr)
206 {
207 	struct dw_mci_exynos_priv_data *priv = host->priv;
208 	/*
209 	 * Exynos4412 and Exynos5250 extends the use of CMD register with the
210 	 * use of bit 29 (which is reserved on standard MSHC controllers) for
211 	 * optionally bypassing the HOLD register for command and data. The
212 	 * HOLD register should be bypassed in case there is no phase shift
213 	 * applied on CMD/DATA that is sent to the card.
214 	 */
215 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
216 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU) {
217 		if (SDMMC_CLKSEL_GET_DRV_WD3(mci_readl(host, CLKSEL64)))
218 			*cmdr |= SDMMC_CMD_USE_HOLD_REG;
219 	 } else {
220 		if (SDMMC_CLKSEL_GET_DRV_WD3(mci_readl(host, CLKSEL)))
221 			*cmdr |= SDMMC_CMD_USE_HOLD_REG;
222 	}
223 }
224 
225 static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
226 {
227 	struct dw_mci_exynos_priv_data *priv = host->priv;
228 	u32 dqs, strobe;
229 
230 	/*
231 	 * Not supported to configure register
232 	 * related to HS400
233 	 */
234 	if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420)
235 		return;
236 
237 	dqs = priv->saved_dqs_en;
238 	strobe = priv->saved_strobe_ctrl;
239 
240 	if (timing == MMC_TIMING_MMC_HS400) {
241 		dqs |= DATA_STROBE_EN;
242 		strobe = DQS_CTRL_RD_DELAY(strobe, priv->dqs_delay);
243 	} else {
244 		dqs &= ~DATA_STROBE_EN;
245 	}
246 
247 	mci_writel(host, HS400_DQS_EN, dqs);
248 	mci_writel(host, HS400_DLINE_CTRL, strobe);
249 }
250 
251 static void dw_mci_exynos_adjust_clock(struct dw_mci *host, unsigned int wanted)
252 {
253 	struct dw_mci_exynos_priv_data *priv = host->priv;
254 	unsigned long actual;
255 	u8 div;
256 	int ret;
257 	/*
258 	 * Don't care if wanted clock is zero or
259 	 * ciu clock is unavailable
260 	 */
261 	if (!wanted || IS_ERR(host->ciu_clk))
262 		return;
263 
264 	/* Guaranteed minimum frequency for cclkin */
265 	if (wanted < EXYNOS_CCLKIN_MIN)
266 		wanted = EXYNOS_CCLKIN_MIN;
267 
268 	if (wanted == priv->cur_speed)
269 		return;
270 
271 	div = dw_mci_exynos_get_ciu_div(host);
272 	ret = clk_set_rate(host->ciu_clk, wanted * div);
273 	if (ret)
274 		dev_warn(host->dev,
275 			"failed to set clk-rate %u error: %d\n",
276 			wanted * div, ret);
277 	actual = clk_get_rate(host->ciu_clk);
278 	host->bus_hz = actual / div;
279 	priv->cur_speed = wanted;
280 	host->current_speed = 0;
281 }
282 
283 static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
284 {
285 	struct dw_mci_exynos_priv_data *priv = host->priv;
286 	unsigned int wanted = ios->clock;
287 	u32 timing = ios->timing, clksel;
288 
289 	switch (timing) {
290 	case MMC_TIMING_MMC_HS400:
291 		/* Update tuned sample timing */
292 		clksel = SDMMC_CLKSEL_UP_SAMPLE(
293 				priv->hs400_timing, priv->tuned_sample);
294 		wanted <<= 1;
295 		break;
296 	case MMC_TIMING_MMC_DDR52:
297 		clksel = priv->ddr_timing;
298 		/* Should be double rate for DDR mode */
299 		if (ios->bus_width == MMC_BUS_WIDTH_8)
300 			wanted <<= 1;
301 		break;
302 	default:
303 		clksel = priv->sdr_timing;
304 	}
305 
306 	/* Set clock timing for the requested speed mode*/
307 	dw_mci_exynos_set_clksel_timing(host, clksel);
308 
309 	/* Configure setting for HS400 */
310 	dw_mci_exynos_config_hs400(host, timing);
311 
312 	/* Configure clock rate */
313 	dw_mci_exynos_adjust_clock(host, wanted);
314 }
315 
316 static int dw_mci_exynos_parse_dt(struct dw_mci *host)
317 {
318 	struct dw_mci_exynos_priv_data *priv;
319 	struct device_node *np = host->dev->of_node;
320 	u32 timing[2];
321 	u32 div = 0;
322 	int idx;
323 	int ret;
324 
325 	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
326 	if (!priv)
327 		return -ENOMEM;
328 
329 	for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
330 		if (of_device_is_compatible(np, exynos_compat[idx].compatible))
331 			priv->ctrl_type = exynos_compat[idx].ctrl_type;
332 	}
333 
334 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
335 		priv->ciu_div = EXYNOS4412_FIXED_CIU_CLK_DIV - 1;
336 	else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
337 		priv->ciu_div = EXYNOS4210_FIXED_CIU_CLK_DIV - 1;
338 	else {
339 		of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div);
340 		priv->ciu_div = div;
341 	}
342 
343 	ret = of_property_read_u32_array(np,
344 			"samsung,dw-mshc-sdr-timing", timing, 2);
345 	if (ret)
346 		return ret;
347 
348 	priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
349 
350 	ret = of_property_read_u32_array(np,
351 			"samsung,dw-mshc-ddr-timing", timing, 2);
352 	if (ret)
353 		return ret;
354 
355 	priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
356 
357 	ret = of_property_read_u32_array(np,
358 			"samsung,dw-mshc-hs400-timing", timing, 2);
359 	if (!ret && of_property_read_u32(np,
360 				"samsung,read-strobe-delay", &priv->dqs_delay))
361 		dev_dbg(host->dev,
362 			"read-strobe-delay is not found, assuming usage of default value\n");
363 
364 	priv->hs400_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1],
365 						HS400_FIXED_CIU_CLK_DIV);
366 	host->priv = priv;
367 	return 0;
368 }
369 
370 static inline u8 dw_mci_exynos_get_clksmpl(struct dw_mci *host)
371 {
372 	struct dw_mci_exynos_priv_data *priv = host->priv;
373 
374 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
375 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
376 		return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL64));
377 	else
378 		return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL));
379 }
380 
381 static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)
382 {
383 	u32 clksel;
384 	struct dw_mci_exynos_priv_data *priv = host->priv;
385 
386 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
387 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
388 		clksel = mci_readl(host, CLKSEL64);
389 	else
390 		clksel = mci_readl(host, CLKSEL);
391 	clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
392 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
393 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
394 		mci_writel(host, CLKSEL64, clksel);
395 	else
396 		mci_writel(host, CLKSEL, clksel);
397 }
398 
399 static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
400 {
401 	struct dw_mci_exynos_priv_data *priv = host->priv;
402 	u32 clksel;
403 	u8 sample;
404 
405 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
406 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
407 		clksel = mci_readl(host, CLKSEL64);
408 	else
409 		clksel = mci_readl(host, CLKSEL);
410 
411 	sample = (clksel + 1) & 0x7;
412 	clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
413 
414 	if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
415 		priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
416 		mci_writel(host, CLKSEL64, clksel);
417 	else
418 		mci_writel(host, CLKSEL, clksel);
419 
420 	return sample;
421 }
422 
423 static s8 dw_mci_exynos_get_best_clksmpl(u8 candiates)
424 {
425 	const u8 iter = 8;
426 	u8 __c;
427 	s8 i, loc = -1;
428 
429 	for (i = 0; i < iter; i++) {
430 		__c = ror8(candiates, i);
431 		if ((__c & 0xc7) == 0xc7) {
432 			loc = i;
433 			goto out;
434 		}
435 	}
436 
437 	for (i = 0; i < iter; i++) {
438 		__c = ror8(candiates, i);
439 		if ((__c & 0x83) == 0x83) {
440 			loc = i;
441 			goto out;
442 		}
443 	}
444 
445 out:
446 	return loc;
447 }
448 
449 static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
450 {
451 	struct dw_mci *host = slot->host;
452 	struct dw_mci_exynos_priv_data *priv = host->priv;
453 	struct mmc_host *mmc = slot->mmc;
454 	u8 start_smpl, smpl, candiates = 0;
455 	s8 found = -1;
456 	int ret = 0;
457 
458 	start_smpl = dw_mci_exynos_get_clksmpl(host);
459 
460 	do {
461 		mci_writel(host, TMOUT, ~0);
462 		smpl = dw_mci_exynos_move_next_clksmpl(host);
463 
464 		if (!mmc_send_tuning(mmc, opcode, NULL))
465 			candiates |= (1 << smpl);
466 
467 	} while (start_smpl != smpl);
468 
469 	found = dw_mci_exynos_get_best_clksmpl(candiates);
470 	if (found >= 0) {
471 		dw_mci_exynos_set_clksmpl(host, found);
472 		priv->tuned_sample = found;
473 	} else {
474 		ret = -EIO;
475 	}
476 
477 	return ret;
478 }
479 
480 static int dw_mci_exynos_prepare_hs400_tuning(struct dw_mci *host,
481 					struct mmc_ios *ios)
482 {
483 	struct dw_mci_exynos_priv_data *priv = host->priv;
484 
485 	dw_mci_exynos_set_clksel_timing(host, priv->hs400_timing);
486 	dw_mci_exynos_adjust_clock(host, (ios->clock) << 1);
487 
488 	return 0;
489 }
490 
491 /* Common capabilities of Exynos4/Exynos5 SoC */
492 static unsigned long exynos_dwmmc_caps[4] = {
493 	MMC_CAP_1_8V_DDR | MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
494 	MMC_CAP_CMD23,
495 	MMC_CAP_CMD23,
496 	MMC_CAP_CMD23,
497 };
498 
499 static const struct dw_mci_drv_data exynos_drv_data = {
500 	.caps			= exynos_dwmmc_caps,
501 	.init			= dw_mci_exynos_priv_init,
502 	.setup_clock		= dw_mci_exynos_setup_clock,
503 	.prepare_command	= dw_mci_exynos_prepare_command,
504 	.set_ios		= dw_mci_exynos_set_ios,
505 	.parse_dt		= dw_mci_exynos_parse_dt,
506 	.execute_tuning		= dw_mci_exynos_execute_tuning,
507 	.prepare_hs400_tuning	= dw_mci_exynos_prepare_hs400_tuning,
508 };
509 
510 static const struct of_device_id dw_mci_exynos_match[] = {
511 	{ .compatible = "samsung,exynos4412-dw-mshc",
512 			.data = &exynos_drv_data, },
513 	{ .compatible = "samsung,exynos5250-dw-mshc",
514 			.data = &exynos_drv_data, },
515 	{ .compatible = "samsung,exynos5420-dw-mshc",
516 			.data = &exynos_drv_data, },
517 	{ .compatible = "samsung,exynos5420-dw-mshc-smu",
518 			.data = &exynos_drv_data, },
519 	{ .compatible = "samsung,exynos7-dw-mshc",
520 			.data = &exynos_drv_data, },
521 	{ .compatible = "samsung,exynos7-dw-mshc-smu",
522 			.data = &exynos_drv_data, },
523 	{},
524 };
525 MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
526 
527 static int dw_mci_exynos_probe(struct platform_device *pdev)
528 {
529 	const struct dw_mci_drv_data *drv_data;
530 	const struct of_device_id *match;
531 
532 	match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
533 	drv_data = match->data;
534 	return dw_mci_pltfm_register(pdev, drv_data);
535 }
536 
537 static const struct dev_pm_ops dw_mci_exynos_pmops = {
538 	SET_SYSTEM_SLEEP_PM_OPS(dw_mci_exynos_suspend, dw_mci_exynos_resume)
539 	.resume_noirq = dw_mci_exynos_resume_noirq,
540 	.thaw_noirq = dw_mci_exynos_resume_noirq,
541 	.restore_noirq = dw_mci_exynos_resume_noirq,
542 };
543 
544 static struct platform_driver dw_mci_exynos_pltfm_driver = {
545 	.probe		= dw_mci_exynos_probe,
546 	.remove		= dw_mci_pltfm_remove,
547 	.driver		= {
548 		.name		= "dwmmc_exynos",
549 		.of_match_table	= dw_mci_exynos_match,
550 		.pm		= &dw_mci_exynos_pmops,
551 	},
552 };
553 
554 module_platform_driver(dw_mci_exynos_pltfm_driver);
555 
556 MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
557 MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
558 MODULE_LICENSE("GPL v2");
559 MODULE_ALIAS("platform:dwmmc_exynos");
560