xref: /openbmc/u-boot/drivers/mmc/renesas-sdhi.c (revision 6f565821)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2018 Marek Vasut <marek.vasut@gmail.com>
4  */
5 
6 #include <common.h>
7 #include <clk.h>
8 #include <fdtdec.h>
9 #include <mmc.h>
10 #include <dm.h>
11 #include <linux/compat.h>
12 #include <linux/dma-direction.h>
13 #include <linux/io.h>
14 #include <linux/sizes.h>
15 #include <power/regulator.h>
16 #include <asm/unaligned.h>
17 
18 #include "tmio-common.h"
19 
20 #if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
21 
22 /* SCC registers */
23 #define RENESAS_SDHI_SCC_DTCNTL			0x800
24 #define   RENESAS_SDHI_SCC_DTCNTL_TAPEN		BIT(0)
25 #define   RENESAS_SDHI_SCC_DTCNTL_TAPNUM_SHIFT	16
26 #define   RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK		0xff
27 #define RENESAS_SDHI_SCC_TAPSET			0x804
28 #define RENESAS_SDHI_SCC_DT2FF			0x808
29 #define RENESAS_SDHI_SCC_CKSEL			0x80c
30 #define   RENESAS_SDHI_SCC_CKSEL_DTSEL		BIT(0)
31 #define RENESAS_SDHI_SCC_RVSCNTL			0x810
32 #define   RENESAS_SDHI_SCC_RVSCNTL_RVSEN		BIT(0)
33 #define RENESAS_SDHI_SCC_RVSREQ			0x814
34 #define   RENESAS_SDHI_SCC_RVSREQ_RVSERR		BIT(2)
35 #define RENESAS_SDHI_SCC_SMPCMP			0x818
36 #define RENESAS_SDHI_SCC_TMPPORT2			0x81c
37 
38 #define RENESAS_SDHI_MAX_TAP 3
39 
40 static unsigned int renesas_sdhi_init_tuning(struct tmio_sd_priv *priv)
41 {
42 	u32 reg;
43 
44 	/* Initialize SCC */
45 	tmio_sd_writel(priv, 0, TMIO_SD_INFO1);
46 
47 	reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL);
48 	reg &= ~TMIO_SD_CLKCTL_SCLKEN;
49 	tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL);
50 
51 	/* Set sampling clock selection range */
52 	tmio_sd_writel(priv, 0x8 << RENESAS_SDHI_SCC_DTCNTL_TAPNUM_SHIFT,
53 			   RENESAS_SDHI_SCC_DTCNTL);
54 
55 	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_DTCNTL);
56 	reg |= RENESAS_SDHI_SCC_DTCNTL_TAPEN;
57 	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_DTCNTL);
58 
59 	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_CKSEL);
60 	reg |= RENESAS_SDHI_SCC_CKSEL_DTSEL;
61 	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_CKSEL);
62 
63 	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
64 	reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
65 	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
66 
67 	tmio_sd_writel(priv, 0x300 /* scc_tappos */,
68 			   RENESAS_SDHI_SCC_DT2FF);
69 
70 	reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL);
71 	reg |= TMIO_SD_CLKCTL_SCLKEN;
72 	tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL);
73 
74 	/* Read TAPNUM */
75 	return (tmio_sd_readl(priv, RENESAS_SDHI_SCC_DTCNTL) >>
76 		RENESAS_SDHI_SCC_DTCNTL_TAPNUM_SHIFT) &
77 		RENESAS_SDHI_SCC_DTCNTL_TAPNUM_MASK;
78 }
79 
80 static void renesas_sdhi_reset_tuning(struct tmio_sd_priv *priv)
81 {
82 	u32 reg;
83 
84 	/* Reset SCC */
85 	reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL);
86 	reg &= ~TMIO_SD_CLKCTL_SCLKEN;
87 	tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL);
88 
89 	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_CKSEL);
90 	reg &= ~RENESAS_SDHI_SCC_CKSEL_DTSEL;
91 	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_CKSEL);
92 
93 	reg = tmio_sd_readl(priv, TMIO_SD_CLKCTL);
94 	reg |= TMIO_SD_CLKCTL_SCLKEN;
95 	tmio_sd_writel(priv, reg, TMIO_SD_CLKCTL);
96 
97 	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
98 	reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
99 	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
100 
101 	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
102 	reg &= ~RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
103 	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
104 }
105 
106 static void renesas_sdhi_prepare_tuning(struct tmio_sd_priv *priv,
107 				       unsigned long tap)
108 {
109 	/* Set sampling clock position */
110 	tmio_sd_writel(priv, tap, RENESAS_SDHI_SCC_TAPSET);
111 }
112 
113 static unsigned int renesas_sdhi_compare_scc_data(struct tmio_sd_priv *priv)
114 {
115 	/* Get comparison of sampling data */
116 	return tmio_sd_readl(priv, RENESAS_SDHI_SCC_SMPCMP);
117 }
118 
119 static int renesas_sdhi_select_tuning(struct tmio_sd_priv *priv,
120 				     unsigned int tap_num, unsigned int taps,
121 				     unsigned int smpcmp)
122 {
123 	unsigned long tap_cnt;  /* counter of tuning success */
124 	unsigned long tap_set;  /* tap position */
125 	unsigned long tap_start;/* start position of tuning success */
126 	unsigned long tap_end;  /* end position of tuning success */
127 	unsigned long ntap;     /* temporary counter of tuning success */
128 	unsigned long match_cnt;/* counter of matching data */
129 	unsigned long i;
130 	bool select = false;
131 	u32 reg;
132 
133 	/* Clear SCC_RVSREQ */
134 	tmio_sd_writel(priv, 0, RENESAS_SDHI_SCC_RVSREQ);
135 
136 	/* Merge the results */
137 	for (i = 0; i < tap_num * 2; i++) {
138 		if (!(taps & BIT(i))) {
139 			taps &= ~BIT(i % tap_num);
140 			taps &= ~BIT((i % tap_num) + tap_num);
141 		}
142 		if (!(smpcmp & BIT(i))) {
143 			smpcmp &= ~BIT(i % tap_num);
144 			smpcmp &= ~BIT((i % tap_num) + tap_num);
145 		}
146 	}
147 
148 	/*
149 	 * Find the longest consecutive run of successful probes.  If that
150 	 * is more than RENESAS_SDHI_MAX_TAP probes long then use the
151 	 * center index as the tap.
152 	 */
153 	tap_cnt = 0;
154 	ntap = 0;
155 	tap_start = 0;
156 	tap_end = 0;
157 	for (i = 0; i < tap_num * 2; i++) {
158 		if (taps & BIT(i))
159 			ntap++;
160 		else {
161 			if (ntap > tap_cnt) {
162 				tap_start = i - ntap;
163 				tap_end = i - 1;
164 				tap_cnt = ntap;
165 			}
166 			ntap = 0;
167 		}
168 	}
169 
170 	if (ntap > tap_cnt) {
171 		tap_start = i - ntap;
172 		tap_end = i - 1;
173 		tap_cnt = ntap;
174 	}
175 
176 	/*
177 	 * If all of the TAP is OK, the sampling clock position is selected by
178 	 * identifying the change point of data.
179 	 */
180 	if (tap_cnt == tap_num * 2) {
181 		match_cnt = 0;
182 		ntap = 0;
183 		tap_start = 0;
184 		tap_end = 0;
185 		for (i = 0; i < tap_num * 2; i++) {
186 			if (smpcmp & BIT(i))
187 				ntap++;
188 			else {
189 				if (ntap > match_cnt) {
190 					tap_start = i - ntap;
191 					tap_end = i - 1;
192 					match_cnt = ntap;
193 				}
194 				ntap = 0;
195 			}
196 		}
197 		if (ntap > match_cnt) {
198 			tap_start = i - ntap;
199 			tap_end = i - 1;
200 			match_cnt = ntap;
201 		}
202 		if (match_cnt)
203 			select = true;
204 	} else if (tap_cnt >= RENESAS_SDHI_MAX_TAP)
205 		select = true;
206 
207 	if (select)
208 		tap_set = ((tap_start + tap_end) / 2) % tap_num;
209 	else
210 		return -EIO;
211 
212 	/* Set SCC */
213 	tmio_sd_writel(priv, tap_set, RENESAS_SDHI_SCC_TAPSET);
214 
215 	/* Enable auto re-tuning */
216 	reg = tmio_sd_readl(priv, RENESAS_SDHI_SCC_RVSCNTL);
217 	reg |= RENESAS_SDHI_SCC_RVSCNTL_RVSEN;
218 	tmio_sd_writel(priv, reg, RENESAS_SDHI_SCC_RVSCNTL);
219 
220 	return 0;
221 }
222 
223 int renesas_sdhi_execute_tuning(struct udevice *dev, uint opcode)
224 {
225 	struct tmio_sd_priv *priv = dev_get_priv(dev);
226 	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
227 	struct mmc *mmc = upriv->mmc;
228 	unsigned int tap_num;
229 	unsigned int taps = 0, smpcmp = 0;
230 	int i, ret = 0;
231 	u32 caps;
232 
233 	/* Only supported on Renesas RCar */
234 	if (!(priv->caps & TMIO_SD_CAP_RCAR_UHS))
235 		return -EINVAL;
236 
237 	/* clock tuning is not needed for upto 52MHz */
238 	if (!((mmc->selected_mode == MMC_HS_200) ||
239 	      (mmc->selected_mode == UHS_SDR104) ||
240 	      (mmc->selected_mode == UHS_SDR50)))
241 		return 0;
242 
243 	tap_num = renesas_sdhi_init_tuning(priv);
244 	if (!tap_num)
245 		/* Tuning is not supported */
246 		goto out;
247 
248 	if (tap_num * 2 >= sizeof(taps) * 8) {
249 		dev_err(dev,
250 			"Too many taps, skipping tuning. Please consider updating size of taps field of tmio_mmc_host\n");
251 		goto out;
252 	}
253 
254 	/* Issue CMD19 twice for each tap */
255 	for (i = 0; i < 2 * tap_num; i++) {
256 		renesas_sdhi_prepare_tuning(priv, i % tap_num);
257 
258 		/* Force PIO for the tuning */
259 		caps = priv->caps;
260 		priv->caps &= ~TMIO_SD_CAP_DMA_INTERNAL;
261 
262 		ret = mmc_send_tuning(mmc, opcode, NULL);
263 
264 		priv->caps = caps;
265 
266 		if (ret == 0)
267 			taps |= BIT(i);
268 
269 		ret = renesas_sdhi_compare_scc_data(priv);
270 		if (ret == 0)
271 			smpcmp |= BIT(i);
272 
273 		mdelay(1);
274 	}
275 
276 	ret = renesas_sdhi_select_tuning(priv, tap_num, taps, smpcmp);
277 
278 out:
279 	if (ret < 0) {
280 		dev_warn(dev, "Tuning procedure failed\n");
281 		renesas_sdhi_reset_tuning(priv);
282 	}
283 
284 	return ret;
285 }
286 #endif
287 
288 static int renesas_sdhi_set_ios(struct udevice *dev)
289 {
290 	int ret = tmio_sd_set_ios(dev);
291 
292 	mdelay(10);
293 
294 #if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
295 	struct tmio_sd_priv *priv = dev_get_priv(dev);
296 
297 	renesas_sdhi_reset_tuning(priv);
298 #endif
299 
300 	return ret;
301 }
302 
303 static const struct dm_mmc_ops renesas_sdhi_ops = {
304 	.send_cmd = tmio_sd_send_cmd,
305 	.set_ios = renesas_sdhi_set_ios,
306 	.get_cd = tmio_sd_get_cd,
307 #if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
308 	.execute_tuning = renesas_sdhi_execute_tuning,
309 #endif
310 };
311 
312 #define RENESAS_GEN2_QUIRKS	TMIO_SD_CAP_RCAR_GEN2
313 #define RENESAS_GEN3_QUIRKS				\
314 	TMIO_SD_CAP_64BIT | TMIO_SD_CAP_RCAR_GEN3 | TMIO_SD_CAP_RCAR_UHS
315 
316 static const struct udevice_id renesas_sdhi_match[] = {
317 	{ .compatible = "renesas,sdhi-r8a7790", .data = RENESAS_GEN2_QUIRKS },
318 	{ .compatible = "renesas,sdhi-r8a7791", .data = RENESAS_GEN2_QUIRKS },
319 	{ .compatible = "renesas,sdhi-r8a7792", .data = RENESAS_GEN2_QUIRKS },
320 	{ .compatible = "renesas,sdhi-r8a7793", .data = RENESAS_GEN2_QUIRKS },
321 	{ .compatible = "renesas,sdhi-r8a7794", .data = RENESAS_GEN2_QUIRKS },
322 	{ .compatible = "renesas,sdhi-r8a7795", .data = RENESAS_GEN3_QUIRKS },
323 	{ .compatible = "renesas,sdhi-r8a7796", .data = RENESAS_GEN3_QUIRKS },
324 	{ .compatible = "renesas,sdhi-r8a77965", .data = RENESAS_GEN3_QUIRKS },
325 	{ .compatible = "renesas,sdhi-r8a77970", .data = RENESAS_GEN3_QUIRKS },
326 	{ .compatible = "renesas,sdhi-r8a77990", .data = RENESAS_GEN3_QUIRKS },
327 	{ .compatible = "renesas,sdhi-r8a77995", .data = RENESAS_GEN3_QUIRKS },
328 	{ /* sentinel */ }
329 };
330 
331 static int renesas_sdhi_probe(struct udevice *dev)
332 {
333 	struct tmio_sd_priv *priv = dev_get_priv(dev);
334 	u32 quirks = dev_get_driver_data(dev);
335 	struct fdt_resource reg_res;
336 	struct clk clk;
337 	DECLARE_GLOBAL_DATA_PTR;
338 	int ret;
339 
340 	if (quirks == RENESAS_GEN2_QUIRKS) {
341 		ret = fdt_get_resource(gd->fdt_blob, dev_of_offset(dev),
342 				       "reg", 0, &reg_res);
343 		if (ret < 0) {
344 			dev_err(dev, "\"reg\" resource not found, ret=%i\n",
345 				ret);
346 			return ret;
347 		}
348 
349 		if (fdt_resource_size(&reg_res) == 0x100)
350 			quirks |= TMIO_SD_CAP_16BIT;
351 	}
352 
353 	ret = clk_get_by_index(dev, 0, &clk);
354 	if (ret < 0) {
355 		dev_err(dev, "failed to get host clock\n");
356 		return ret;
357 	}
358 
359 	/* set to max rate */
360 	priv->mclk = clk_set_rate(&clk, ULONG_MAX);
361 	if (IS_ERR_VALUE(priv->mclk)) {
362 		dev_err(dev, "failed to set rate for host clock\n");
363 		clk_free(&clk);
364 		return priv->mclk;
365 	}
366 
367 	ret = clk_enable(&clk);
368 	clk_free(&clk);
369 	if (ret) {
370 		dev_err(dev, "failed to enable host clock\n");
371 		return ret;
372 	}
373 
374 	ret = tmio_sd_probe(dev, quirks);
375 #if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
376 	if (!ret)
377 		renesas_sdhi_reset_tuning(priv);
378 #endif
379 	return ret;
380 }
381 
382 U_BOOT_DRIVER(renesas_sdhi) = {
383 	.name = "renesas-sdhi",
384 	.id = UCLASS_MMC,
385 	.of_match = renesas_sdhi_match,
386 	.bind = tmio_sd_bind,
387 	.probe = renesas_sdhi_probe,
388 	.priv_auto_alloc_size = sizeof(struct tmio_sd_priv),
389 	.platdata_auto_alloc_size = sizeof(struct tmio_sd_plat),
390 	.ops = &renesas_sdhi_ops,
391 };
392