xref: /openbmc/linux/drivers/mmc/host/sdhci-cadence.c (revision 453431a5)
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[];
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 	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS04_ACK),
101 				 0, 10);
102 	if (ret)
103 		return ret;
104 
105 	tmp = FIELD_PREP(SDHCI_CDNS_HRS04_WDATA, data) |
106 	      FIELD_PREP(SDHCI_CDNS_HRS04_ADDR, addr);
107 	writel(tmp, reg);
108 
109 	tmp |= SDHCI_CDNS_HRS04_WR;
110 	writel(tmp, reg);
111 
112 	ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
113 	if (ret)
114 		return ret;
115 
116 	tmp &= ~SDHCI_CDNS_HRS04_WR;
117 	writel(tmp, reg);
118 
119 	ret = readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS04_ACK),
120 				 0, 10);
121 
122 	return ret;
123 }
124 
125 static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
126 {
127 	unsigned int count = 0;
128 	int i;
129 
130 	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
131 		if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
132 			count++;
133 
134 	return count;
135 }
136 
137 static void sdhci_cdns_phy_param_parse(struct device_node *np,
138 				       struct sdhci_cdns_priv *priv)
139 {
140 	struct sdhci_cdns_phy_param *p = priv->phy_params;
141 	u32 val;
142 	int ret, i;
143 
144 	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++) {
145 		ret = of_property_read_u32(np, sdhci_cdns_phy_cfgs[i].property,
146 					   &val);
147 		if (ret)
148 			continue;
149 
150 		p->addr = sdhci_cdns_phy_cfgs[i].addr;
151 		p->data = val;
152 		p++;
153 	}
154 }
155 
156 static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
157 {
158 	int ret, i;
159 
160 	for (i = 0; i < priv->nr_phy_params; i++) {
161 		ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
162 					       priv->phy_params[i].data);
163 		if (ret)
164 			return ret;
165 	}
166 
167 	return 0;
168 }
169 
170 static void *sdhci_cdns_priv(struct sdhci_host *host)
171 {
172 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
173 
174 	return sdhci_pltfm_priv(pltfm_host);
175 }
176 
177 static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
178 {
179 	/*
180 	 * Cadence's spec says the Timeout Clock Frequency is the same as the
181 	 * Base Clock Frequency.
182 	 */
183 	return host->max_clk;
184 }
185 
186 static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
187 {
188 	u32 tmp;
189 
190 	/* The speed mode for eMMC is selected by HRS06 register */
191 	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
192 	tmp &= ~SDHCI_CDNS_HRS06_MODE;
193 	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_MODE, mode);
194 	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
195 }
196 
197 static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
198 {
199 	u32 tmp;
200 
201 	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
202 	return FIELD_GET(SDHCI_CDNS_HRS06_MODE, tmp);
203 }
204 
205 static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
206 {
207 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
208 	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
209 	u32 tmp;
210 	int i, ret;
211 
212 	if (WARN_ON(!FIELD_FIT(SDHCI_CDNS_HRS06_TUNE, val)))
213 		return -EINVAL;
214 
215 	tmp = readl(reg);
216 	tmp &= ~SDHCI_CDNS_HRS06_TUNE;
217 	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_TUNE, val);
218 
219 	/*
220 	 * Workaround for IP errata:
221 	 * The IP6116 SD/eMMC PHY design has a timing issue on receive data
222 	 * path. Send tune request twice.
223 	 */
224 	for (i = 0; i < 2; i++) {
225 		tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
226 		writel(tmp, reg);
227 
228 		ret = readl_poll_timeout(reg, tmp,
229 					 !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
230 					 0, 1);
231 		if (ret)
232 			return ret;
233 	}
234 
235 	return 0;
236 }
237 
238 /*
239  * In SD mode, software must not use the hardware tuning and instead perform
240  * an almost identical procedure to eMMC.
241  */
242 static int sdhci_cdns_execute_tuning(struct sdhci_host *host, u32 opcode)
243 {
244 	int cur_streak = 0;
245 	int max_streak = 0;
246 	int end_of_streak = 0;
247 	int i;
248 
249 	/*
250 	 * Do not execute tuning for UHS_SDR50 or UHS_DDR50.
251 	 * The delay is set by probe, based on the DT properties.
252 	 */
253 	if (host->timing != MMC_TIMING_MMC_HS200 &&
254 	    host->timing != MMC_TIMING_UHS_SDR104)
255 		return 0;
256 
257 	for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
258 		if (sdhci_cdns_set_tune_val(host, i) ||
259 		    mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
260 			cur_streak = 0;
261 		} else { /* good */
262 			cur_streak++;
263 			if (cur_streak > max_streak) {
264 				max_streak = cur_streak;
265 				end_of_streak = i;
266 			}
267 		}
268 	}
269 
270 	if (!max_streak) {
271 		dev_err(mmc_dev(host->mmc), "no tuning point found\n");
272 		return -EIO;
273 	}
274 
275 	return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
276 }
277 
278 static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
279 					 unsigned int timing)
280 {
281 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
282 	u32 mode;
283 
284 	switch (timing) {
285 	case MMC_TIMING_MMC_HS:
286 		mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR;
287 		break;
288 	case MMC_TIMING_MMC_DDR52:
289 		mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR;
290 		break;
291 	case MMC_TIMING_MMC_HS200:
292 		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
293 		break;
294 	case MMC_TIMING_MMC_HS400:
295 		if (priv->enhanced_strobe)
296 			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
297 		else
298 			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
299 		break;
300 	default:
301 		mode = SDHCI_CDNS_HRS06_MODE_SD;
302 		break;
303 	}
304 
305 	sdhci_cdns_set_emmc_mode(priv, mode);
306 
307 	/* For SD, fall back to the default handler */
308 	if (mode == SDHCI_CDNS_HRS06_MODE_SD)
309 		sdhci_set_uhs_signaling(host, timing);
310 }
311 
312 static const struct sdhci_ops sdhci_cdns_ops = {
313 	.set_clock = sdhci_set_clock,
314 	.get_timeout_clock = sdhci_cdns_get_timeout_clock,
315 	.set_bus_width = sdhci_set_bus_width,
316 	.reset = sdhci_reset,
317 	.platform_execute_tuning = sdhci_cdns_execute_tuning,
318 	.set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
319 };
320 
321 static const struct sdhci_pltfm_data sdhci_cdns_uniphier_pltfm_data = {
322 	.ops = &sdhci_cdns_ops,
323 	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
324 };
325 
326 static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
327 	.ops = &sdhci_cdns_ops,
328 };
329 
330 static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
331 					     struct mmc_ios *ios)
332 {
333 	struct sdhci_host *host = mmc_priv(mmc);
334 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
335 	u32 mode;
336 
337 	priv->enhanced_strobe = ios->enhanced_strobe;
338 
339 	mode = sdhci_cdns_get_emmc_mode(priv);
340 
341 	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400 && ios->enhanced_strobe)
342 		sdhci_cdns_set_emmc_mode(priv,
343 					 SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
344 
345 	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400ES && !ios->enhanced_strobe)
346 		sdhci_cdns_set_emmc_mode(priv,
347 					 SDHCI_CDNS_HRS06_MODE_MMC_HS400);
348 }
349 
350 static int sdhci_cdns_probe(struct platform_device *pdev)
351 {
352 	struct sdhci_host *host;
353 	const struct sdhci_pltfm_data *data;
354 	struct sdhci_pltfm_host *pltfm_host;
355 	struct sdhci_cdns_priv *priv;
356 	struct clk *clk;
357 	unsigned int nr_phy_params;
358 	int ret;
359 	struct device *dev = &pdev->dev;
360 	static const u16 version = SDHCI_SPEC_400 << SDHCI_SPEC_VER_SHIFT;
361 
362 	clk = devm_clk_get(dev, NULL);
363 	if (IS_ERR(clk))
364 		return PTR_ERR(clk);
365 
366 	ret = clk_prepare_enable(clk);
367 	if (ret)
368 		return ret;
369 
370 	data = of_device_get_match_data(dev);
371 	if (!data)
372 		data = &sdhci_cdns_pltfm_data;
373 
374 	nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
375 	host = sdhci_pltfm_init(pdev, data,
376 				struct_size(priv, phy_params, nr_phy_params));
377 	if (IS_ERR(host)) {
378 		ret = PTR_ERR(host);
379 		goto disable_clk;
380 	}
381 
382 	pltfm_host = sdhci_priv(host);
383 	pltfm_host->clk = clk;
384 
385 	priv = sdhci_pltfm_priv(pltfm_host);
386 	priv->nr_phy_params = nr_phy_params;
387 	priv->hrs_addr = host->ioaddr;
388 	priv->enhanced_strobe = false;
389 	host->ioaddr += SDHCI_CDNS_SRS_BASE;
390 	host->mmc_host_ops.hs400_enhanced_strobe =
391 				sdhci_cdns_hs400_enhanced_strobe;
392 	sdhci_enable_v4_mode(host);
393 	__sdhci_read_caps(host, &version, NULL, NULL);
394 
395 	sdhci_get_of_property(pdev);
396 
397 	ret = mmc_of_parse(host->mmc);
398 	if (ret)
399 		goto free;
400 
401 	sdhci_cdns_phy_param_parse(dev->of_node, priv);
402 
403 	ret = sdhci_cdns_phy_init(priv);
404 	if (ret)
405 		goto free;
406 
407 	ret = sdhci_add_host(host);
408 	if (ret)
409 		goto free;
410 
411 	return 0;
412 free:
413 	sdhci_pltfm_free(pdev);
414 disable_clk:
415 	clk_disable_unprepare(clk);
416 
417 	return ret;
418 }
419 
420 #ifdef CONFIG_PM_SLEEP
421 static int sdhci_cdns_resume(struct device *dev)
422 {
423 	struct sdhci_host *host = dev_get_drvdata(dev);
424 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
425 	struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host);
426 	int ret;
427 
428 	ret = clk_prepare_enable(pltfm_host->clk);
429 	if (ret)
430 		return ret;
431 
432 	ret = sdhci_cdns_phy_init(priv);
433 	if (ret)
434 		goto disable_clk;
435 
436 	ret = sdhci_resume_host(host);
437 	if (ret)
438 		goto disable_clk;
439 
440 	return 0;
441 
442 disable_clk:
443 	clk_disable_unprepare(pltfm_host->clk);
444 
445 	return ret;
446 }
447 #endif
448 
449 static const struct dev_pm_ops sdhci_cdns_pm_ops = {
450 	SET_SYSTEM_SLEEP_PM_OPS(sdhci_pltfm_suspend, sdhci_cdns_resume)
451 };
452 
453 static const struct of_device_id sdhci_cdns_match[] = {
454 	{
455 		.compatible = "socionext,uniphier-sd4hc",
456 		.data = &sdhci_cdns_uniphier_pltfm_data,
457 	},
458 	{ .compatible = "cdns,sd4hc" },
459 	{ /* sentinel */ }
460 };
461 MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
462 
463 static struct platform_driver sdhci_cdns_driver = {
464 	.driver = {
465 		.name = "sdhci-cdns",
466 		.pm = &sdhci_cdns_pm_ops,
467 		.of_match_table = sdhci_cdns_match,
468 	},
469 	.probe = sdhci_cdns_probe,
470 	.remove = sdhci_pltfm_unregister,
471 };
472 module_platform_driver(sdhci_cdns_driver);
473 
474 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
475 MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver");
476 MODULE_LICENSE("GPL");
477