summaryrefslogtreecommitdiffstats
path: root/drivers/mmc/host/sdhci-cadence.c
blob: 7a343b87b5e581814235bdf4bbe0cd660732d27e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
/*
 * Copyright (C) 2016 Socionext Inc.
 *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/of.h>

#include "sdhci-pltfm.h"

/* HRS - Host Register Set (specific to Cadence) */
#define SDHCI_CDNS_HRS04		0x10		/* PHY access port */
#define   SDHCI_CDNS_HRS04_ACK			BIT(26)
#define   SDHCI_CDNS_HRS04_RD			BIT(25)
#define   SDHCI_CDNS_HRS04_WR			BIT(24)
#define   SDHCI_CDNS_HRS04_RDATA		GENMASK(23, 16)
#define   SDHCI_CDNS_HRS04_WDATA		GENMASK(15, 8)
#define   SDHCI_CDNS_HRS04_ADDR			GENMASK(5, 0)

#define SDHCI_CDNS_HRS06		0x18		/* eMMC control */
#define   SDHCI_CDNS_HRS06_TUNE_UP		BIT(15)
#define   SDHCI_CDNS_HRS06_TUNE			GENMASK(13, 8)
#define   SDHCI_CDNS_HRS06_MODE			GENMASK(2, 0)
#define   SDHCI_CDNS_HRS06_MODE_SD		0x0
#define   SDHCI_CDNS_HRS06_MODE_MMC_SDR		0x2
#define   SDHCI_CDNS_HRS06_MODE_MMC_DDR		0x3
#define   SDHCI_CDNS_HRS06_MODE_MMC_HS200	0x4
#define   SDHCI_CDNS_HRS06_MODE_MMC_HS400	0x5
#define   SDHCI_CDNS_HRS06_MODE_MMC_HS400ES	0x6

/* SRS - Slot Register Set (SDHCI-compatible) */
#define SDHCI_CDNS_SRS_BASE		0x200

/* PHY */
#define SDHCI_CDNS_PHY_DLY_SD_HS	0x00
#define SDHCI_CDNS_PHY_DLY_SD_DEFAULT	0x01
#define SDHCI_CDNS_PHY_DLY_UHS_SDR12	0x02
#define SDHCI_CDNS_PHY_DLY_UHS_SDR25	0x03
#define SDHCI_CDNS_PHY_DLY_UHS_SDR50	0x04
#define SDHCI_CDNS_PHY_DLY_UHS_DDR50	0x05
#define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY	0x06
#define SDHCI_CDNS_PHY_DLY_EMMC_SDR	0x07
#define SDHCI_CDNS_PHY_DLY_EMMC_DDR	0x08
#define SDHCI_CDNS_PHY_DLY_SDCLK	0x0b
#define SDHCI_CDNS_PHY_DLY_HSMMC	0x0c
#define SDHCI_CDNS_PHY_DLY_STROBE	0x0d

/*
 * The tuned val register is 6 bit-wide, but not the whole of the range is
 * available.  The range 0-42 seems to be available (then 43 wraps around to 0)
 * but I am not quite sure if it is official.  Use only 0 to 39 for safety.
 */
#define SDHCI_CDNS_MAX_TUNING_LOOP	40

struct sdhci_cdns_phy_param {
	u8 addr;
	u8 data;
};

struct sdhci_cdns_priv {
	void __iomem *hrs_addr;
	bool enhanced_strobe;
	unsigned int nr_phy_params;
	struct sdhci_cdns_phy_param phy_params[0];
};

struct sdhci_cdns_phy_cfg {
	const char *property;
	u8 addr;
};

static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
	{ "cdns,phy-input-delay-sd-highspeed", SDHCI_CDNS_PHY_DLY_SD_HS, },
	{ "cdns,phy-input-delay-legacy", SDHCI_CDNS_PHY_DLY_SD_DEFAULT, },
	{ "cdns,phy-input-delay-sd-uhs-sdr12", SDHCI_CDNS_PHY_DLY_UHS_SDR12, },
	{ "cdns,phy-input-delay-sd-uhs-sdr25", SDHCI_CDNS_PHY_DLY_UHS_SDR25, },
	{ "cdns,phy-input-delay-sd-uhs-sdr50", SDHCI_CDNS_PHY_DLY_UHS_SDR50, },
	{ "cdns,phy-input-delay-sd-uhs-ddr50", SDHCI_CDNS_PHY_DLY_UHS_DDR50, },
	{ "cdns,phy-input-delay-mmc-highspeed", SDHCI_CDNS_PHY_DLY_EMMC_SDR, },
	{ "cdns,phy-input-delay-mmc-ddr", SDHCI_CDNS_PHY_DLY_EMMC_DDR, },
	{ "cdns,phy-dll-delay-sdclk", SDHCI_CDNS_PHY_DLY_SDCLK, },
	{ "cdns,phy-dll-delay-sdclk-hsmmc", SDHCI_CDNS_PHY_DLY_HSMMC, },
	{ "cdns,phy-dll-delay-strobe", SDHCI_CDNS_PHY_DLY_STROBE, },
};

static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
				    u8 addr, u8 data)
{
	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04;
	u32 tmp;
	int ret;

	tmp = FIELD_PREP(SDHCI_CDNS_HRS04_WDATA, data) |
	      FIELD_PREP(SDHCI_CDNS_HRS04_ADDR, addr);
	writel(tmp, reg);

	tmp |= SDHCI_CDNS_HRS04_WR;
	writel(tmp, reg);

	ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
	if (ret)
		return ret;

	tmp &= ~SDHCI_CDNS_HRS04_WR;
	writel(tmp, reg);

	return 0;
}

static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
{
	unsigned int count = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
		if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
			count++;

	return count;
}

static void sdhci_cdns_phy_param_parse(struct device_node *np,
				       struct sdhci_cdns_priv *priv)
{
	struct sdhci_cdns_phy_param *p = priv->phy_params;
	u32 val;
	int ret, i;

	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++) {
		ret = of_property_read_u32(np, sdhci_cdns_phy_cfgs[i].property,
					   &val);
		if (ret)
			continue;

		p->addr = sdhci_cdns_phy_cfgs[i].addr;
		p->data = val;
		p++;
	}
}

static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
{
	int ret, i;

	for (i = 0; i < priv->nr_phy_params; i++) {
		ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
					       priv->phy_params[i].data);
		if (ret)
			return ret;
	}

	return 0;
}

static inline void *sdhci_cdns_priv(struct sdhci_host *host)
{
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);

	return sdhci_pltfm_priv(pltfm_host);
}

static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
{
	/*
	 * Cadence's spec says the Timeout Clock Frequency is the same as the
	 * Base Clock Frequency.
	 */
	return host->max_clk;
}

static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
{
	u32 tmp;

	/* The speed mode for eMMC is selected by HRS06 register */
	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
	tmp &= ~SDHCI_CDNS_HRS06_MODE;
	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_MODE, mode);
	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
}

static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
{
	u32 tmp;

	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
	return FIELD_GET(SDHCI_CDNS_HRS06_MODE, tmp);
}

static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
					 unsigned int timing)
{
	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
	u32 mode;

	switch (timing) {
	case MMC_TIMING_MMC_HS:
		mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR;
		break;
	case MMC_TIMING_MMC_DDR52:
		mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR;
		break;
	case MMC_TIMING_MMC_HS200:
		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
		break;
	case MMC_TIMING_MMC_HS400:
		if (priv->enhanced_strobe)
			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
		else
			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
		break;
	default:
		mode = SDHCI_CDNS_HRS06_MODE_SD;
		break;
	}

	sdhci_cdns_set_emmc_mode(priv, mode);

	/* For SD, fall back to the default handler */
	if (mode == SDHCI_CDNS_HRS06_MODE_SD)
		sdhci_set_uhs_signaling(host, timing);
}

static const struct sdhci_ops sdhci_cdns_ops = {
	.set_clock = sdhci_set_clock,
	.get_timeout_clock = sdhci_cdns_get_timeout_clock,
	.set_bus_width = sdhci_set_bus_width,
	.reset = sdhci_reset,
	.set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
};

static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
	.ops = &sdhci_cdns_ops,
};

static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
{
	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
	u32 tmp;
	int i, ret;

	if (WARN_ON(!FIELD_FIT(SDHCI_CDNS_HRS06_TUNE, val)))
		return -EINVAL;

	tmp = readl(reg);
	tmp &= ~SDHCI_CDNS_HRS06_TUNE;
	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_TUNE, val);

	/*
	 * Workaround for IP errata:
	 * The IP6116 SD/eMMC PHY design has a timing issue on receive data
	 * path. Send tune request twice.
	 */
	for (i = 0; i < 2; i++) {
		tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
		writel(tmp, reg);

		ret = readl_poll_timeout(reg, tmp,
					 !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
					 0, 1);
		if (ret)
			return ret;
	}

	return 0;
}

static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
	struct sdhci_host *host = mmc_priv(mmc);
	int cur_streak = 0;
	int max_streak = 0;
	int end_of_streak = 0;
	int i;

	/*
	 * This handler only implements the eMMC tuning that is specific to
	 * this controller.  Fall back to the standard method for SD timing.
	 */
	if (host->timing != MMC_TIMING_MMC_HS200)
		return sdhci_execute_tuning(mmc, opcode);

	if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200))
		return -EINVAL;

	for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
		if (sdhci_cdns_set_tune_val(host, i) ||
		    mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
			cur_streak = 0;
		} else { /* good */
			cur_streak++;
			if (cur_streak > max_streak) {
				max_streak = cur_streak;
				end_of_streak = i;
			}
		}
	}

	if (!max_streak) {
		dev_err(mmc_dev(host->mmc), "no tuning point found\n");
		return -EIO;
	}

	return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
}

static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
					     struct mmc_ios *ios)
{
	struct sdhci_host *host = mmc_priv(mmc);
	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
	u32 mode;

	priv->enhanced_strobe = ios->enhanced_strobe;

	mode = sdhci_cdns_get_emmc_mode(priv);

	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400 && ios->enhanced_strobe)
		sdhci_cdns_set_emmc_mode(priv,
					 SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);

	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400ES && !ios->enhanced_strobe)
		sdhci_cdns_set_emmc_mode(priv,
					 SDHCI_CDNS_HRS06_MODE_MMC_HS400);
}

static int sdhci_cdns_probe(struct platform_device *pdev)
{
	struct sdhci_host *host;
	struct sdhci_pltfm_host *pltfm_host;
	struct sdhci_cdns_priv *priv;
	struct clk *clk;
	size_t priv_size;
	unsigned int nr_phy_params;
	int ret;
	struct device *dev = &pdev->dev;

	clk = devm_clk_get(dev, NULL);
	if (IS_ERR(clk))
		return PTR_ERR(clk);

	ret = clk_prepare_enable(clk);
	if (ret)
		return ret;

	nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
	priv_size = sizeof(*priv) + sizeof(priv->phy_params[0]) * nr_phy_params;
	host = sdhci_pltfm_init(pdev, &sdhci_cdns_pltfm_data, priv_size);
	if (IS_ERR(host)) {
		ret = PTR_ERR(host);
		goto disable_clk;
	}

	pltfm_host = sdhci_priv(host);
	pltfm_host->clk = clk;

	priv = sdhci_pltfm_priv(pltfm_host);
	priv->nr_phy_params = nr_phy_params;
	priv->hrs_addr = host->ioaddr;
	priv->enhanced_strobe = false;
	host->ioaddr += SDHCI_CDNS_SRS_BASE;
	host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
	host->mmc_host_ops.hs400_enhanced_strobe =
				sdhci_cdns_hs400_enhanced_strobe;

	sdhci_get_of_property(pdev);

	ret = mmc_of_parse(host->mmc);
	if (ret)
		goto free;

	sdhci_cdns_phy_param_parse(dev->of_node, priv);

	ret = sdhci_cdns_phy_init(priv);
	if (ret)
		goto free;

	ret = sdhci_add_host(host);
	if (ret)
		goto free;

	return 0;
free:
	sdhci_pltfm_free(pdev);
disable_clk:
	clk_disable_unprepare(clk);

	return ret;
}

#ifdef CONFIG_PM_SLEEP
static int sdhci_cdns_resume(struct device *dev)
{
	struct sdhci_host *host = dev_get_drvdata(dev);
	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
	struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host);
	int ret;

	ret = clk_prepare_enable(pltfm_host->clk);
	if (ret)
		return ret;

	ret = sdhci_cdns_phy_init(priv);
	if (ret)
		goto disable_clk;

	ret = sdhci_resume_host(host);
	if (ret)
		goto disable_clk;

	return 0;

disable_clk:
	clk_disable_unprepare(pltfm_host->clk);

	return ret;
}
#endif

static const struct dev_pm_ops sdhci_cdns_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(sdhci_pltfm_suspend, sdhci_cdns_resume)
};

static const struct of_device_id sdhci_cdns_match[] = {
	{ .compatible = "socionext,uniphier-sd4hc" },
	{ .compatible = "cdns,sd4hc" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sdhci_cdns_match);

static struct platform_driver sdhci_cdns_driver = {
	.driver = {
		.name = "sdhci-cdns",
		.pm = &sdhci_cdns_pm_ops,
		.of_match_table = sdhci_cdns_match,
	},
	.probe = sdhci_cdns_probe,
	.remove = sdhci_pltfm_unregister,
};
module_platform_driver(sdhci_cdns_driver);

MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver");
MODULE_LICENSE("GPL");