xref: /openbmc/linux/drivers/mmc/host/sdhci-cadence.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2016 Socionext Inc.
4  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/bits.h>
9 #include <linux/iopoll.h>
10 #include <linux/module.h>
11 #include <linux/mmc/host.h>
12 #include <linux/mmc/mmc.h>
13 #include <linux/of.h>
14 #include <linux/of_device.h>
15 
16 #include "sdhci-pltfm.h"
17 
18 /* HRS - Host Register Set (specific to Cadence) */
19 #define SDHCI_CDNS_HRS04		0x10		/* PHY access port */
20 #define   SDHCI_CDNS_HRS04_ACK			BIT(26)
21 #define   SDHCI_CDNS_HRS04_RD			BIT(25)
22 #define   SDHCI_CDNS_HRS04_WR			BIT(24)
23 #define   SDHCI_CDNS_HRS04_RDATA		GENMASK(23, 16)
24 #define   SDHCI_CDNS_HRS04_WDATA		GENMASK(15, 8)
25 #define   SDHCI_CDNS_HRS04_ADDR			GENMASK(5, 0)
26 
27 #define SDHCI_CDNS_HRS06		0x18		/* eMMC control */
28 #define   SDHCI_CDNS_HRS06_TUNE_UP		BIT(15)
29 #define   SDHCI_CDNS_HRS06_TUNE			GENMASK(13, 8)
30 #define   SDHCI_CDNS_HRS06_MODE			GENMASK(2, 0)
31 #define   SDHCI_CDNS_HRS06_MODE_SD		0x0
32 #define   SDHCI_CDNS_HRS06_MODE_MMC_SDR		0x2
33 #define   SDHCI_CDNS_HRS06_MODE_MMC_DDR		0x3
34 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS200	0x4
35 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS400	0x5
36 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS400ES	0x6
37 
38 /* SRS - Slot Register Set (SDHCI-compatible) */
39 #define SDHCI_CDNS_SRS_BASE		0x200
40 
41 /* PHY */
42 #define SDHCI_CDNS_PHY_DLY_SD_HS	0x00
43 #define SDHCI_CDNS_PHY_DLY_SD_DEFAULT	0x01
44 #define SDHCI_CDNS_PHY_DLY_UHS_SDR12	0x02
45 #define SDHCI_CDNS_PHY_DLY_UHS_SDR25	0x03
46 #define SDHCI_CDNS_PHY_DLY_UHS_SDR50	0x04
47 #define SDHCI_CDNS_PHY_DLY_UHS_DDR50	0x05
48 #define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY	0x06
49 #define SDHCI_CDNS_PHY_DLY_EMMC_SDR	0x07
50 #define SDHCI_CDNS_PHY_DLY_EMMC_DDR	0x08
51 #define SDHCI_CDNS_PHY_DLY_SDCLK	0x0b
52 #define SDHCI_CDNS_PHY_DLY_HSMMC	0x0c
53 #define SDHCI_CDNS_PHY_DLY_STROBE	0x0d
54 
55 /*
56  * The tuned val register is 6 bit-wide, but not the whole of the range is
57  * available.  The range 0-42 seems to be available (then 43 wraps around to 0)
58  * but I am not quite sure if it is official.  Use only 0 to 39 for safety.
59  */
60 #define SDHCI_CDNS_MAX_TUNING_LOOP	40
61 
62 struct sdhci_cdns_phy_param {
63 	u8 addr;
64 	u8 data;
65 };
66 
67 struct sdhci_cdns_priv {
68 	void __iomem *hrs_addr;
69 	bool enhanced_strobe;
70 	unsigned int nr_phy_params;
71 	struct sdhci_cdns_phy_param phy_params[0];
72 };
73 
74 struct sdhci_cdns_phy_cfg {
75 	const char *property;
76 	u8 addr;
77 };
78 
79 static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
80 	{ "cdns,phy-input-delay-sd-highspeed", SDHCI_CDNS_PHY_DLY_SD_HS, },
81 	{ "cdns,phy-input-delay-legacy", SDHCI_CDNS_PHY_DLY_SD_DEFAULT, },
82 	{ "cdns,phy-input-delay-sd-uhs-sdr12", SDHCI_CDNS_PHY_DLY_UHS_SDR12, },
83 	{ "cdns,phy-input-delay-sd-uhs-sdr25", SDHCI_CDNS_PHY_DLY_UHS_SDR25, },
84 	{ "cdns,phy-input-delay-sd-uhs-sdr50", SDHCI_CDNS_PHY_DLY_UHS_SDR50, },
85 	{ "cdns,phy-input-delay-sd-uhs-ddr50", SDHCI_CDNS_PHY_DLY_UHS_DDR50, },
86 	{ "cdns,phy-input-delay-mmc-highspeed", SDHCI_CDNS_PHY_DLY_EMMC_SDR, },
87 	{ "cdns,phy-input-delay-mmc-ddr", SDHCI_CDNS_PHY_DLY_EMMC_DDR, },
88 	{ "cdns,phy-dll-delay-sdclk", SDHCI_CDNS_PHY_DLY_SDCLK, },
89 	{ "cdns,phy-dll-delay-sdclk-hsmmc", SDHCI_CDNS_PHY_DLY_HSMMC, },
90 	{ "cdns,phy-dll-delay-strobe", SDHCI_CDNS_PHY_DLY_STROBE, },
91 };
92 
93 static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
94 				    u8 addr, u8 data)
95 {
96 	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04;
97 	u32 tmp;
98 	int ret;
99 
100 	tmp = FIELD_PREP(SDHCI_CDNS_HRS04_WDATA, data) |
101 	      FIELD_PREP(SDHCI_CDNS_HRS04_ADDR, addr);
102 	writel(tmp, reg);
103 
104 	tmp |= SDHCI_CDNS_HRS04_WR;
105 	writel(tmp, reg);
106 
107 	ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
108 	if (ret)
109 		return ret;
110 
111 	tmp &= ~SDHCI_CDNS_HRS04_WR;
112 	writel(tmp, reg);
113 
114 	return 0;
115 }
116 
117 static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
118 {
119 	unsigned int count = 0;
120 	int i;
121 
122 	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
123 		if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
124 			count++;
125 
126 	return count;
127 }
128 
129 static void sdhci_cdns_phy_param_parse(struct device_node *np,
130 				       struct sdhci_cdns_priv *priv)
131 {
132 	struct sdhci_cdns_phy_param *p = priv->phy_params;
133 	u32 val;
134 	int ret, i;
135 
136 	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++) {
137 		ret = of_property_read_u32(np, sdhci_cdns_phy_cfgs[i].property,
138 					   &val);
139 		if (ret)
140 			continue;
141 
142 		p->addr = sdhci_cdns_phy_cfgs[i].addr;
143 		p->data = val;
144 		p++;
145 	}
146 }
147 
148 static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
149 {
150 	int ret, i;
151 
152 	for (i = 0; i < priv->nr_phy_params; i++) {
153 		ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
154 					       priv->phy_params[i].data);
155 		if (ret)
156 			return ret;
157 	}
158 
159 	return 0;
160 }
161 
162 static void *sdhci_cdns_priv(struct sdhci_host *host)
163 {
164 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
165 
166 	return sdhci_pltfm_priv(pltfm_host);
167 }
168 
169 static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
170 {
171 	/*
172 	 * Cadence's spec says the Timeout Clock Frequency is the same as the
173 	 * Base Clock Frequency.
174 	 */
175 	return host->max_clk;
176 }
177 
178 static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
179 {
180 	u32 tmp;
181 
182 	/* The speed mode for eMMC is selected by HRS06 register */
183 	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
184 	tmp &= ~SDHCI_CDNS_HRS06_MODE;
185 	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_MODE, mode);
186 	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
187 }
188 
189 static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
190 {
191 	u32 tmp;
192 
193 	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
194 	return FIELD_GET(SDHCI_CDNS_HRS06_MODE, tmp);
195 }
196 
197 static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
198 					 unsigned int timing)
199 {
200 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
201 	u32 mode;
202 
203 	switch (timing) {
204 	case MMC_TIMING_MMC_HS:
205 		mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR;
206 		break;
207 	case MMC_TIMING_MMC_DDR52:
208 		mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR;
209 		break;
210 	case MMC_TIMING_MMC_HS200:
211 		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
212 		break;
213 	case MMC_TIMING_MMC_HS400:
214 		if (priv->enhanced_strobe)
215 			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
216 		else
217 			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
218 		break;
219 	default:
220 		mode = SDHCI_CDNS_HRS06_MODE_SD;
221 		break;
222 	}
223 
224 	sdhci_cdns_set_emmc_mode(priv, mode);
225 
226 	/* For SD, fall back to the default handler */
227 	if (mode == SDHCI_CDNS_HRS06_MODE_SD)
228 		sdhci_set_uhs_signaling(host, timing);
229 }
230 
231 static const struct sdhci_ops sdhci_cdns_ops = {
232 	.set_clock = sdhci_set_clock,
233 	.get_timeout_clock = sdhci_cdns_get_timeout_clock,
234 	.set_bus_width = sdhci_set_bus_width,
235 	.reset = sdhci_reset,
236 	.set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
237 };
238 
239 static const struct sdhci_pltfm_data sdhci_cdns_uniphier_pltfm_data = {
240 	.ops = &sdhci_cdns_ops,
241 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
242 };
243 
244 static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
245 	.ops = &sdhci_cdns_ops,
246 };
247 
248 static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
249 {
250 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
251 	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
252 	u32 tmp;
253 	int i, ret;
254 
255 	if (WARN_ON(!FIELD_FIT(SDHCI_CDNS_HRS06_TUNE, val)))
256 		return -EINVAL;
257 
258 	tmp = readl(reg);
259 	tmp &= ~SDHCI_CDNS_HRS06_TUNE;
260 	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_TUNE, val);
261 
262 	/*
263 	 * Workaround for IP errata:
264 	 * The IP6116 SD/eMMC PHY design has a timing issue on receive data
265 	 * path. Send tune request twice.
266 	 */
267 	for (i = 0; i < 2; i++) {
268 		tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
269 		writel(tmp, reg);
270 
271 		ret = readl_poll_timeout(reg, tmp,
272 					 !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
273 					 0, 1);
274 		if (ret)
275 			return ret;
276 	}
277 
278 	return 0;
279 }
280 
281 static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode)
282 {
283 	struct sdhci_host *host = mmc_priv(mmc);
284 	int cur_streak = 0;
285 	int max_streak = 0;
286 	int end_of_streak = 0;
287 	int i;
288 
289 	/*
290 	 * This handler only implements the eMMC tuning that is specific to
291 	 * this controller.  Fall back to the standard method for SD timing.
292 	 */
293 	if (host->timing != MMC_TIMING_MMC_HS200)
294 		return sdhci_execute_tuning(mmc, opcode);
295 
296 	if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200))
297 		return -EINVAL;
298 
299 	for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
300 		if (sdhci_cdns_set_tune_val(host, i) ||
301 		    mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
302 			cur_streak = 0;
303 		} else { /* good */
304 			cur_streak++;
305 			if (cur_streak > max_streak) {
306 				max_streak = cur_streak;
307 				end_of_streak = i;
308 			}
309 		}
310 	}
311 
312 	if (!max_streak) {
313 		dev_err(mmc_dev(host->mmc), "no tuning point found\n");
314 		return -EIO;
315 	}
316 
317 	return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
318 }
319 
320 static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
321 					     struct mmc_ios *ios)
322 {
323 	struct sdhci_host *host = mmc_priv(mmc);
324 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
325 	u32 mode;
326 
327 	priv->enhanced_strobe = ios->enhanced_strobe;
328 
329 	mode = sdhci_cdns_get_emmc_mode(priv);
330 
331 	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400 && ios->enhanced_strobe)
332 		sdhci_cdns_set_emmc_mode(priv,
333 					 SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
334 
335 	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400ES && !ios->enhanced_strobe)
336 		sdhci_cdns_set_emmc_mode(priv,
337 					 SDHCI_CDNS_HRS06_MODE_MMC_HS400);
338 }
339 
340 static int sdhci_cdns_probe(struct platform_device *pdev)
341 {
342 	struct sdhci_host *host;
343 	const struct sdhci_pltfm_data *data;
344 	struct sdhci_pltfm_host *pltfm_host;
345 	struct sdhci_cdns_priv *priv;
346 	struct clk *clk;
347 	unsigned int nr_phy_params;
348 	int ret;
349 	struct device *dev = &pdev->dev;
350 	static const u16 version = SDHCI_SPEC_400 << SDHCI_SPEC_VER_SHIFT;
351 
352 	clk = devm_clk_get(dev, NULL);
353 	if (IS_ERR(clk))
354 		return PTR_ERR(clk);
355 
356 	ret = clk_prepare_enable(clk);
357 	if (ret)
358 		return ret;
359 
360 	data = of_device_get_match_data(dev);
361 	if (!data)
362 		data = &sdhci_cdns_pltfm_data;
363 
364 	nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
365 	host = sdhci_pltfm_init(pdev, data,
366 				struct_size(priv, phy_params, nr_phy_params));
367 	if (IS_ERR(host)) {
368 		ret = PTR_ERR(host);
369 		goto disable_clk;
370 	}
371 
372 	pltfm_host = sdhci_priv(host);
373 	pltfm_host->clk = clk;
374 
375 	priv = sdhci_pltfm_priv(pltfm_host);
376 	priv->nr_phy_params = nr_phy_params;
377 	priv->hrs_addr = host->ioaddr;
378 	priv->enhanced_strobe = false;
379 	host->ioaddr += SDHCI_CDNS_SRS_BASE;
380 	host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
381 	host->mmc_host_ops.hs400_enhanced_strobe =
382 				sdhci_cdns_hs400_enhanced_strobe;
383 	sdhci_enable_v4_mode(host);
384 	__sdhci_read_caps(host, &version, NULL, NULL);
385 
386 	sdhci_get_of_property(pdev);
387 
388 	ret = mmc_of_parse(host->mmc);
389 	if (ret)
390 		goto free;
391 
392 	sdhci_cdns_phy_param_parse(dev->of_node, priv);
393 
394 	ret = sdhci_cdns_phy_init(priv);
395 	if (ret)
396 		goto free;
397 
398 	ret = sdhci_add_host(host);
399 	if (ret)
400 		goto free;
401 
402 	return 0;
403 free:
404 	sdhci_pltfm_free(pdev);
405 disable_clk:
406 	clk_disable_unprepare(clk);
407 
408 	return ret;
409 }
410 
411 #ifdef CONFIG_PM_SLEEP
412 static int sdhci_cdns_resume(struct device *dev)
413 {
414 	struct sdhci_host *host = dev_get_drvdata(dev);
415 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
416 	struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host);
417 	int ret;
418 
419 	ret = clk_prepare_enable(pltfm_host->clk);
420 	if (ret)
421 		return ret;
422 
423 	ret = sdhci_cdns_phy_init(priv);
424 	if (ret)
425 		goto disable_clk;
426 
427 	ret = sdhci_resume_host(host);
428 	if (ret)
429 		goto disable_clk;
430 
431 	return 0;
432 
433 disable_clk:
434 	clk_disable_unprepare(pltfm_host->clk);
435 
436 	return ret;
437 }
438 #endif
439 
440 static const struct dev_pm_ops sdhci_cdns_pm_ops = {
441 	SET_SYSTEM_SLEEP_PM_OPS(sdhci_pltfm_suspend, sdhci_cdns_resume)
442 };
443 
444 static const struct of_device_id sdhci_cdns_match[] = {
445 	{
446 		.compatible = "socionext,uniphier-sd4hc",
447 		.data = &sdhci_cdns_uniphier_pltfm_data,
448 	},
449 	{ .compatible = "cdns,sd4hc" },
450 	{ /* sentinel */ }
451 };
452 MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
453 
454 static struct platform_driver sdhci_cdns_driver = {
455 	.driver = {
456 		.name = "sdhci-cdns",
457 		.pm = &sdhci_cdns_pm_ops,
458 		.of_match_table = sdhci_cdns_match,
459 	},
460 	.probe = sdhci_cdns_probe,
461 	.remove = sdhci_pltfm_unregister,
462 };
463 module_platform_driver(sdhci_cdns_driver);
464 
465 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
466 MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver");
467 MODULE_LICENSE("GPL");
468