xref: /openbmc/linux/drivers/mmc/host/sdhci-cadence.c (revision f2f4bf5a)
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 
15 #include "sdhci-pltfm.h"
16 
17 /* HRS - Host Register Set (specific to Cadence) */
18 #define SDHCI_CDNS_HRS04		0x10		/* PHY access port */
19 #define   SDHCI_CDNS_HRS04_ACK			BIT(26)
20 #define   SDHCI_CDNS_HRS04_RD			BIT(25)
21 #define   SDHCI_CDNS_HRS04_WR			BIT(24)
22 #define   SDHCI_CDNS_HRS04_RDATA		GENMASK(23, 16)
23 #define   SDHCI_CDNS_HRS04_WDATA		GENMASK(15, 8)
24 #define   SDHCI_CDNS_HRS04_ADDR			GENMASK(5, 0)
25 
26 #define SDHCI_CDNS_HRS06		0x18		/* eMMC control */
27 #define   SDHCI_CDNS_HRS06_TUNE_UP		BIT(15)
28 #define   SDHCI_CDNS_HRS06_TUNE			GENMASK(13, 8)
29 #define   SDHCI_CDNS_HRS06_MODE			GENMASK(2, 0)
30 #define   SDHCI_CDNS_HRS06_MODE_SD		0x0
31 #define   SDHCI_CDNS_HRS06_MODE_MMC_SDR		0x2
32 #define   SDHCI_CDNS_HRS06_MODE_MMC_DDR		0x3
33 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS200	0x4
34 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS400	0x5
35 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS400ES	0x6
36 
37 /* SRS - Slot Register Set (SDHCI-compatible) */
38 #define SDHCI_CDNS_SRS_BASE		0x200
39 
40 /* PHY */
41 #define SDHCI_CDNS_PHY_DLY_SD_HS	0x00
42 #define SDHCI_CDNS_PHY_DLY_SD_DEFAULT	0x01
43 #define SDHCI_CDNS_PHY_DLY_UHS_SDR12	0x02
44 #define SDHCI_CDNS_PHY_DLY_UHS_SDR25	0x03
45 #define SDHCI_CDNS_PHY_DLY_UHS_SDR50	0x04
46 #define SDHCI_CDNS_PHY_DLY_UHS_DDR50	0x05
47 #define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY	0x06
48 #define SDHCI_CDNS_PHY_DLY_EMMC_SDR	0x07
49 #define SDHCI_CDNS_PHY_DLY_EMMC_DDR	0x08
50 #define SDHCI_CDNS_PHY_DLY_SDCLK	0x0b
51 #define SDHCI_CDNS_PHY_DLY_HSMMC	0x0c
52 #define SDHCI_CDNS_PHY_DLY_STROBE	0x0d
53 
54 /*
55  * The tuned val register is 6 bit-wide, but not the whole of the range is
56  * available.  The range 0-42 seems to be available (then 43 wraps around to 0)
57  * but I am not quite sure if it is official.  Use only 0 to 39 for safety.
58  */
59 #define SDHCI_CDNS_MAX_TUNING_LOOP	40
60 
61 struct sdhci_cdns_phy_param {
62 	u8 addr;
63 	u8 data;
64 };
65 
66 struct sdhci_cdns_priv {
67 	void __iomem *hrs_addr;
68 	bool enhanced_strobe;
69 	unsigned int nr_phy_params;
70 	struct sdhci_cdns_phy_param phy_params[0];
71 };
72 
73 struct sdhci_cdns_phy_cfg {
74 	const char *property;
75 	u8 addr;
76 };
77 
78 static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
79 	{ "cdns,phy-input-delay-sd-highspeed", SDHCI_CDNS_PHY_DLY_SD_HS, },
80 	{ "cdns,phy-input-delay-legacy", SDHCI_CDNS_PHY_DLY_SD_DEFAULT, },
81 	{ "cdns,phy-input-delay-sd-uhs-sdr12", SDHCI_CDNS_PHY_DLY_UHS_SDR12, },
82 	{ "cdns,phy-input-delay-sd-uhs-sdr25", SDHCI_CDNS_PHY_DLY_UHS_SDR25, },
83 	{ "cdns,phy-input-delay-sd-uhs-sdr50", SDHCI_CDNS_PHY_DLY_UHS_SDR50, },
84 	{ "cdns,phy-input-delay-sd-uhs-ddr50", SDHCI_CDNS_PHY_DLY_UHS_DDR50, },
85 	{ "cdns,phy-input-delay-mmc-highspeed", SDHCI_CDNS_PHY_DLY_EMMC_SDR, },
86 	{ "cdns,phy-input-delay-mmc-ddr", SDHCI_CDNS_PHY_DLY_EMMC_DDR, },
87 	{ "cdns,phy-dll-delay-sdclk", SDHCI_CDNS_PHY_DLY_SDCLK, },
88 	{ "cdns,phy-dll-delay-sdclk-hsmmc", SDHCI_CDNS_PHY_DLY_HSMMC, },
89 	{ "cdns,phy-dll-delay-strobe", SDHCI_CDNS_PHY_DLY_STROBE, },
90 };
91 
92 static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
93 				    u8 addr, u8 data)
94 {
95 	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04;
96 	u32 tmp;
97 	int ret;
98 
99 	tmp = FIELD_PREP(SDHCI_CDNS_HRS04_WDATA, data) |
100 	      FIELD_PREP(SDHCI_CDNS_HRS04_ADDR, addr);
101 	writel(tmp, reg);
102 
103 	tmp |= SDHCI_CDNS_HRS04_WR;
104 	writel(tmp, reg);
105 
106 	ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
107 	if (ret)
108 		return ret;
109 
110 	tmp &= ~SDHCI_CDNS_HRS04_WR;
111 	writel(tmp, reg);
112 
113 	return 0;
114 }
115 
116 static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
117 {
118 	unsigned int count = 0;
119 	int i;
120 
121 	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
122 		if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
123 			count++;
124 
125 	return count;
126 }
127 
128 static void sdhci_cdns_phy_param_parse(struct device_node *np,
129 				       struct sdhci_cdns_priv *priv)
130 {
131 	struct sdhci_cdns_phy_param *p = priv->phy_params;
132 	u32 val;
133 	int ret, i;
134 
135 	for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++) {
136 		ret = of_property_read_u32(np, sdhci_cdns_phy_cfgs[i].property,
137 					   &val);
138 		if (ret)
139 			continue;
140 
141 		p->addr = sdhci_cdns_phy_cfgs[i].addr;
142 		p->data = val;
143 		p++;
144 	}
145 }
146 
147 static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
148 {
149 	int ret, i;
150 
151 	for (i = 0; i < priv->nr_phy_params; i++) {
152 		ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
153 					       priv->phy_params[i].data);
154 		if (ret)
155 			return ret;
156 	}
157 
158 	return 0;
159 }
160 
161 static inline void *sdhci_cdns_priv(struct sdhci_host *host)
162 {
163 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
164 
165 	return sdhci_pltfm_priv(pltfm_host);
166 }
167 
168 static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
169 {
170 	/*
171 	 * Cadence's spec says the Timeout Clock Frequency is the same as the
172 	 * Base Clock Frequency.
173 	 */
174 	return host->max_clk;
175 }
176 
177 static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
178 {
179 	u32 tmp;
180 
181 	/* The speed mode for eMMC is selected by HRS06 register */
182 	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
183 	tmp &= ~SDHCI_CDNS_HRS06_MODE;
184 	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_MODE, mode);
185 	writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
186 }
187 
188 static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
189 {
190 	u32 tmp;
191 
192 	tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
193 	return FIELD_GET(SDHCI_CDNS_HRS06_MODE, tmp);
194 }
195 
196 static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
197 					 unsigned int timing)
198 {
199 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
200 	u32 mode;
201 
202 	switch (timing) {
203 	case MMC_TIMING_MMC_HS:
204 		mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR;
205 		break;
206 	case MMC_TIMING_MMC_DDR52:
207 		mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR;
208 		break;
209 	case MMC_TIMING_MMC_HS200:
210 		mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
211 		break;
212 	case MMC_TIMING_MMC_HS400:
213 		if (priv->enhanced_strobe)
214 			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
215 		else
216 			mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
217 		break;
218 	default:
219 		mode = SDHCI_CDNS_HRS06_MODE_SD;
220 		break;
221 	}
222 
223 	sdhci_cdns_set_emmc_mode(priv, mode);
224 
225 	/* For SD, fall back to the default handler */
226 	if (mode == SDHCI_CDNS_HRS06_MODE_SD)
227 		sdhci_set_uhs_signaling(host, timing);
228 }
229 
230 static const struct sdhci_ops sdhci_cdns_ops = {
231 	.set_clock = sdhci_set_clock,
232 	.get_timeout_clock = sdhci_cdns_get_timeout_clock,
233 	.set_bus_width = sdhci_set_bus_width,
234 	.reset = sdhci_reset,
235 	.set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
236 };
237 
238 static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
239 	.ops = &sdhci_cdns_ops,
240 };
241 
242 static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
243 {
244 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
245 	void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
246 	u32 tmp;
247 	int i, ret;
248 
249 	if (WARN_ON(!FIELD_FIT(SDHCI_CDNS_HRS06_TUNE, val)))
250 		return -EINVAL;
251 
252 	tmp = readl(reg);
253 	tmp &= ~SDHCI_CDNS_HRS06_TUNE;
254 	tmp |= FIELD_PREP(SDHCI_CDNS_HRS06_TUNE, val);
255 
256 	/*
257 	 * Workaround for IP errata:
258 	 * The IP6116 SD/eMMC PHY design has a timing issue on receive data
259 	 * path. Send tune request twice.
260 	 */
261 	for (i = 0; i < 2; i++) {
262 		tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
263 		writel(tmp, reg);
264 
265 		ret = readl_poll_timeout(reg, tmp,
266 					 !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
267 					 0, 1);
268 		if (ret)
269 			return ret;
270 	}
271 
272 	return 0;
273 }
274 
275 static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode)
276 {
277 	struct sdhci_host *host = mmc_priv(mmc);
278 	int cur_streak = 0;
279 	int max_streak = 0;
280 	int end_of_streak = 0;
281 	int i;
282 
283 	/*
284 	 * This handler only implements the eMMC tuning that is specific to
285 	 * this controller.  Fall back to the standard method for SD timing.
286 	 */
287 	if (host->timing != MMC_TIMING_MMC_HS200)
288 		return sdhci_execute_tuning(mmc, opcode);
289 
290 	if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200))
291 		return -EINVAL;
292 
293 	for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
294 		if (sdhci_cdns_set_tune_val(host, i) ||
295 		    mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
296 			cur_streak = 0;
297 		} else { /* good */
298 			cur_streak++;
299 			if (cur_streak > max_streak) {
300 				max_streak = cur_streak;
301 				end_of_streak = i;
302 			}
303 		}
304 	}
305 
306 	if (!max_streak) {
307 		dev_err(mmc_dev(host->mmc), "no tuning point found\n");
308 		return -EIO;
309 	}
310 
311 	return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
312 }
313 
314 static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
315 					     struct mmc_ios *ios)
316 {
317 	struct sdhci_host *host = mmc_priv(mmc);
318 	struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
319 	u32 mode;
320 
321 	priv->enhanced_strobe = ios->enhanced_strobe;
322 
323 	mode = sdhci_cdns_get_emmc_mode(priv);
324 
325 	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400 && ios->enhanced_strobe)
326 		sdhci_cdns_set_emmc_mode(priv,
327 					 SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
328 
329 	if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400ES && !ios->enhanced_strobe)
330 		sdhci_cdns_set_emmc_mode(priv,
331 					 SDHCI_CDNS_HRS06_MODE_MMC_HS400);
332 }
333 
334 static int sdhci_cdns_probe(struct platform_device *pdev)
335 {
336 	struct sdhci_host *host;
337 	struct sdhci_pltfm_host *pltfm_host;
338 	struct sdhci_cdns_priv *priv;
339 	struct clk *clk;
340 	size_t priv_size;
341 	unsigned int nr_phy_params;
342 	int ret;
343 	struct device *dev = &pdev->dev;
344 
345 	clk = devm_clk_get(dev, NULL);
346 	if (IS_ERR(clk))
347 		return PTR_ERR(clk);
348 
349 	ret = clk_prepare_enable(clk);
350 	if (ret)
351 		return ret;
352 
353 	nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
354 	priv_size = sizeof(*priv) + sizeof(priv->phy_params[0]) * nr_phy_params;
355 	host = sdhci_pltfm_init(pdev, &sdhci_cdns_pltfm_data, priv_size);
356 	if (IS_ERR(host)) {
357 		ret = PTR_ERR(host);
358 		goto disable_clk;
359 	}
360 
361 	pltfm_host = sdhci_priv(host);
362 	pltfm_host->clk = clk;
363 
364 	priv = sdhci_pltfm_priv(pltfm_host);
365 	priv->nr_phy_params = nr_phy_params;
366 	priv->hrs_addr = host->ioaddr;
367 	priv->enhanced_strobe = false;
368 	host->ioaddr += SDHCI_CDNS_SRS_BASE;
369 	host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
370 	host->mmc_host_ops.hs400_enhanced_strobe =
371 				sdhci_cdns_hs400_enhanced_strobe;
372 	sdhci_enable_v4_mode(host);
373 
374 	sdhci_get_of_property(pdev);
375 
376 	ret = mmc_of_parse(host->mmc);
377 	if (ret)
378 		goto free;
379 
380 	sdhci_cdns_phy_param_parse(dev->of_node, priv);
381 
382 	ret = sdhci_cdns_phy_init(priv);
383 	if (ret)
384 		goto free;
385 
386 	ret = sdhci_add_host(host);
387 	if (ret)
388 		goto free;
389 
390 	return 0;
391 free:
392 	sdhci_pltfm_free(pdev);
393 disable_clk:
394 	clk_disable_unprepare(clk);
395 
396 	return ret;
397 }
398 
399 #ifdef CONFIG_PM_SLEEP
400 static int sdhci_cdns_resume(struct device *dev)
401 {
402 	struct sdhci_host *host = dev_get_drvdata(dev);
403 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
404 	struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host);
405 	int ret;
406 
407 	ret = clk_prepare_enable(pltfm_host->clk);
408 	if (ret)
409 		return ret;
410 
411 	ret = sdhci_cdns_phy_init(priv);
412 	if (ret)
413 		goto disable_clk;
414 
415 	ret = sdhci_resume_host(host);
416 	if (ret)
417 		goto disable_clk;
418 
419 	return 0;
420 
421 disable_clk:
422 	clk_disable_unprepare(pltfm_host->clk);
423 
424 	return ret;
425 }
426 #endif
427 
428 static const struct dev_pm_ops sdhci_cdns_pm_ops = {
429 	SET_SYSTEM_SLEEP_PM_OPS(sdhci_pltfm_suspend, sdhci_cdns_resume)
430 };
431 
432 static const struct of_device_id sdhci_cdns_match[] = {
433 	{ .compatible = "socionext,uniphier-sd4hc" },
434 	{ .compatible = "cdns,sd4hc" },
435 	{ /* sentinel */ }
436 };
437 MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
438 
439 static struct platform_driver sdhci_cdns_driver = {
440 	.driver = {
441 		.name = "sdhci-cdns",
442 		.pm = &sdhci_cdns_pm_ops,
443 		.of_match_table = sdhci_cdns_match,
444 	},
445 	.probe = sdhci_cdns_probe,
446 	.remove = sdhci_pltfm_unregister,
447 };
448 module_platform_driver(sdhci_cdns_driver);
449 
450 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
451 MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver");
452 MODULE_LICENSE("GPL");
453