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      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * Copyright (C) 2018 Marek Vasut <marek.vasut (at) 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(dev_get_priv(dev));
    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