drivers/mmc/host/sdhci-of-ma35d1.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2024 Nuvoton Technology Corp.
   4  *
   5  * Author: Shan-Chun Hung <[email protected]>
   6  */
   7
   8 #include <linux/align.h>
   9 #include <linux/array_size.h>
  10 #include <linux/bits.h>
  11 #include <linux/build_bug.h>
  12 #include <linux/clk.h>
  13 #include <linux/delay.h>
  14 #include <linux/dev_printk.h>
  15 #include <linux/device.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/err.h>
  18 #include <linux/math.h>
  19 #include <linux/mfd/syscon.h>
  20 #include <linux/minmax.h>
  21 #include <linux/mmc/card.h>
  22 #include <linux/mmc/host.h>
  23 #include <linux/mod_devicetable.h>
  24 #include <linux/module.h>
  25 #include <linux/pinctrl/consumer.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/regmap.h>
  28 #include <linux/reset.h>
  29 #include <linux/sizes.h>
  30 #include <linux/types.h>
  31
  32 #include "sdhci-pltfm.h"
  33 #include "sdhci.h"
  34
  35 #define MA35_SYS_MISCFCR0       0x070
  36 #define MA35_SDHCI_MSHCCTL      0x508
  37 #define MA35_SDHCI_MBIUCTL      0x510
  38
  39 #define MA35_SDHCI_CMD_CONFLICT_CHK     BIT(0)
  40 #define MA35_SDHCI_INCR_MSK             GENMASK(3, 0)
  41 #define MA35_SDHCI_INCR16               BIT(3)
  42 #define MA35_SDHCI_INCR8                BIT(2)
  43
  44 struct ma35_priv {
  45         struct reset_control    *rst;
  46         struct pinctrl          *pinctrl;
  47         struct pinctrl_state    *pins_uhs;
  48         struct pinctrl_state    *pins_default;
  49 };
  50
  51 struct ma35_restore_data {
  52         u32     reg;
  53         u32     width;
  54 };
  55
  56 static const struct ma35_restore_data restore_data[] = {
  57         { SDHCI_CLOCK_CONTROL,          sizeof(u32)},
  58         { SDHCI_BLOCK_SIZE,             sizeof(u32)},
  59         { SDHCI_INT_ENABLE,             sizeof(u32)},
  60         { SDHCI_SIGNAL_ENABLE,          sizeof(u32)},
  61         { SDHCI_AUTO_CMD_STATUS,        sizeof(u32)},
  62         { SDHCI_HOST_CONTROL,           sizeof(u32)},
  63         { SDHCI_TIMEOUT_CONTROL,        sizeof(u8) },
  64         { MA35_SDHCI_MSHCCTL,           sizeof(u16)},
  65         { MA35_SDHCI_MBIUCTL,           sizeof(u16)},
  66 };
  67
  68 /*
  69  * If DMA addr spans 128MB boundary, we split the DMA transfer into two
  70  * so that each DMA transfer doesn't exceed the boundary.
  71  */
  72 static void ma35_adma_write_desc(struct sdhci_host *host, void **desc, dma_addr_t addr, int len,
  73                                  unsigned int cmd)
  74 {
  75         int tmplen, offset;
  76
  77         if (likely(!len || (ALIGN(addr, SZ_128M) == ALIGN(addr + len - 1, SZ_128M)))) {
  78                 sdhci_adma_write_desc(host, desc, addr, len, cmd);
  79                 return;
  80         }
  81
  82         offset = addr & (SZ_128M - 1);
  83         tmplen = SZ_128M - offset;
  84         sdhci_adma_write_desc(host, desc, addr, tmplen, cmd);
  85
  86         addr += tmplen;
  87         len -= tmplen;
  88         sdhci_adma_write_desc(host, desc, addr, len, cmd);
  89 }
  90
  91 static void ma35_set_clock(struct sdhci_host *host, unsigned int clock)
  92 {
  93         u32 ctl;
  94
  95         /*
  96          * If the clock frequency exceeds MMC_HIGH_52_MAX_DTR,
  97          * disable command conflict check.
  98          */
  99         ctl = sdhci_readw(host, MA35_SDHCI_MSHCCTL);
 100         if (clock > MMC_HIGH_52_MAX_DTR)
 101                 ctl &= ~MA35_SDHCI_CMD_CONFLICT_CHK;
 102         else
 103                 ctl |= MA35_SDHCI_CMD_CONFLICT_CHK;
 104         sdhci_writew(host, ctl, MA35_SDHCI_MSHCCTL);
 105
 106         sdhci_set_clock(host, clock);
 107 }
 108
 109 static int ma35_start_signal_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
 110 {
 111         struct sdhci_host *host = mmc_priv(mmc);
 112         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 113         struct ma35_priv *priv = sdhci_pltfm_priv(pltfm_host);
 114
 115         switch (ios->signal_voltage) {
 116         case MMC_SIGNAL_VOLTAGE_180:
 117                 if (!IS_ERR(priv->pinctrl) && !IS_ERR(priv->pins_uhs))
 118                         pinctrl_select_state(priv->pinctrl, priv->pins_uhs);
 119                 break;
 120         case MMC_SIGNAL_VOLTAGE_330:
 121                 if (!IS_ERR(priv->pinctrl) && !IS_ERR(priv->pins_default))
 122                         pinctrl_select_state(priv->pinctrl, priv->pins_default);
 123                 break;
 124         default:
 125                 dev_err(mmc_dev(host->mmc), "Unsupported signal voltage!\n");
 126                 return -EINVAL;
 127         }
 128
 129         return sdhci_start_signal_voltage_switch(mmc, ios);
 130 }
 131
 132 static void ma35_voltage_switch(struct sdhci_host *host)
 133 {
 134         /* Wait for 5ms after set 1.8V signal enable bit */
 135         fsleep(5000);
 136 }
 137
 138 static int ma35_execute_tuning(struct mmc_host *mmc, u32 opcode)
 139 {
 140         struct sdhci_host *host = mmc_priv(mmc);
 141         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 142         struct ma35_priv *priv = sdhci_pltfm_priv(pltfm_host);
 143         int idx;
 144         u32 regs[ARRAY_SIZE(restore_data)] = {};
 145
 146         /*
 147          * Limitations require a reset of SD/eMMC before tuning and
 148          * saving the registers before resetting, then restoring
 149          * after the reset.
 150          */
 151         for (idx = 0; idx < ARRAY_SIZE(restore_data); idx++) {
 152                 if (restore_data[idx].width == sizeof(u32))
 153                         regs[idx] = sdhci_readl(host, restore_data[idx].reg);
 154                 else if (restore_data[idx].width == sizeof(u16))
 155                         regs[idx] = sdhci_readw(host, restore_data[idx].reg);
 156                 else if (restore_data[idx].width == sizeof(u8))
 157                         regs[idx] = sdhci_readb(host, restore_data[idx].reg);
 158         }
 159
 160         reset_control_assert(priv->rst);
 161         reset_control_deassert(priv->rst);
 162
 163         for (idx = 0; idx < ARRAY_SIZE(restore_data); idx++) {
 164                 if (restore_data[idx].width == sizeof(u32))
 165                         sdhci_writel(host, regs[idx], restore_data[idx].reg);
 166                 else if (restore_data[idx].width == sizeof(u16))
 167                         sdhci_writew(host, regs[idx], restore_data[idx].reg);
 168                 else if (restore_data[idx].width == sizeof(u8))
 169                         sdhci_writeb(host, regs[idx], restore_data[idx].reg);
 170         }
 171
 172         return sdhci_execute_tuning(mmc, opcode);
 173 }
 174
 175 static const struct sdhci_ops sdhci_ma35_ops = {
 176         .set_clock              = ma35_set_clock,
 177         .set_bus_width          = sdhci_set_bus_width,
 178         .set_uhs_signaling      = sdhci_set_uhs_signaling,
 179         .get_max_clock          = sdhci_pltfm_clk_get_max_clock,
 180         .reset                  = sdhci_reset,
 181         .adma_write_desc        = ma35_adma_write_desc,
 182         .voltage_switch         = ma35_voltage_switch,
 183 };
 184
 185 static const struct sdhci_pltfm_data sdhci_ma35_pdata = {
 186         .ops = &sdhci_ma35_ops,
 187         .quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
 188         .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN | SDHCI_QUIRK2_BROKEN_DDR50 |
 189                    SDHCI_QUIRK2_ACMD23_BROKEN,
 190 };
 191
 192 static int ma35_probe(struct platform_device *pdev)
 193 {
 194         struct device *dev = &pdev->dev;
 195         struct sdhci_pltfm_host *pltfm_host;
 196         struct sdhci_host *host;
 197         struct ma35_priv *priv;
 198         int err;
 199         u32 extra, ctl;
 200
 201         host = sdhci_pltfm_init(pdev, &sdhci_ma35_pdata, sizeof(struct ma35_priv));
 202         if (IS_ERR(host))
 203                 return PTR_ERR(host);
 204
 205         /* Extra adma table cnt for cross 128M boundary handling. */
 206         extra = DIV_ROUND_UP_ULL(dma_get_required_mask(dev), SZ_128M);
 207         extra = min(extra, SDHCI_MAX_SEGS);
 208
 209         host->adma_table_cnt += extra;
 210         pltfm_host = sdhci_priv(host);
 211         priv = sdhci_pltfm_priv(pltfm_host);
 212
 213         pltfm_host->clk = devm_clk_get_optional_enabled(dev, NULL);
 214         if (IS_ERR(pltfm_host->clk)) {
 215                 err = dev_err_probe(dev, PTR_ERR(pltfm_host->clk), "failed to get clk\n");
 216                 goto err_sdhci;
 217         }
 218
 219         err = mmc_of_parse(host->mmc);
 220         if (err)
 221                 goto err_sdhci;
 222
 223         priv->rst = devm_reset_control_get_exclusive(dev, NULL);
 224         if (IS_ERR(priv->rst)) {
 225                 err = dev_err_probe(dev, PTR_ERR(priv->rst), "failed to get reset control\n");
 226                 goto err_sdhci;
 227         }
 228
 229         sdhci_get_of_property(pdev);
 230
 231         priv->pinctrl = devm_pinctrl_get(dev);
 232         if (!IS_ERR(priv->pinctrl)) {
 233                 priv->pins_default = pinctrl_lookup_state(priv->pinctrl, "default");
 234                 priv->pins_uhs = pinctrl_lookup_state(priv->pinctrl, "state_uhs");
 235                 pinctrl_select_state(priv->pinctrl, priv->pins_default);
 236         }
 237
 238         if (!(host->quirks2 & SDHCI_QUIRK2_NO_1_8_V)) {
 239                 struct regmap   *regmap;
 240                 u32             reg;
 241
 242                 regmap = syscon_regmap_lookup_by_phandle(dev_of_node(dev), "nuvoton,sys");
 243                 if (!IS_ERR(regmap)) {
 244                         /* Enable SDHCI voltage stable for 1.8V */
 245                         regmap_read(regmap, MA35_SYS_MISCFCR0, &reg);
 246                         reg |= BIT(17);
 247                         regmap_write(regmap, MA35_SYS_MISCFCR0, reg);
 248                 }
 249
 250                 host->mmc_host_ops.start_signal_voltage_switch =
 251                                         ma35_start_signal_voltage_switch;
 252         }
 253
 254         host->mmc_host_ops.execute_tuning = ma35_execute_tuning;
 255
 256         err = sdhci_add_host(host);
 257         if (err)
 258                 goto err_sdhci;
 259
 260         /*
 261          * Split data into chunks of 16 or 8 bytes for transmission.
 262          * Each chunk transfer is guaranteed to be uninterrupted on the bus.
 263          * This likely corresponds to the AHB bus DMA burst size.
 264          */
 265         ctl = sdhci_readw(host, MA35_SDHCI_MBIUCTL);
 266         ctl &= ~MA35_SDHCI_INCR_MSK;
 267         ctl |= MA35_SDHCI_INCR16 | MA35_SDHCI_INCR8;
 268         sdhci_writew(host, ctl, MA35_SDHCI_MBIUCTL);
 269
 270         return 0;
 271
 272 err_sdhci:
 273         sdhci_pltfm_free(pdev);
 274         return err;
 275 }
 276
 277 static void ma35_disable_card_clk(struct sdhci_host *host)
 278 {
 279         u16 ctrl;
 280
 281         ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
 282         if (ctrl & SDHCI_CLOCK_CARD_EN) {
 283                 ctrl &= ~SDHCI_CLOCK_CARD_EN;
 284                 sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
 285         }
 286 }
 287
 288 static void ma35_remove(struct platform_device *pdev)
 289 {
 290         struct sdhci_host *host = platform_get_drvdata(pdev);
 291
 292         sdhci_remove_host(host, 0);
 293         ma35_disable_card_clk(host);
 294         sdhci_pltfm_free(pdev);
 295 }
 296
 297 static const struct of_device_id sdhci_ma35_dt_ids[] = {
 298         { .compatible = "nuvoton,ma35d1-sdhci" },
 299         {}
 300 };
 301
 302 static struct platform_driver sdhci_ma35_driver = {
 303         .driver = {
 304                 .name   = "sdhci-ma35",
 305                 .of_match_table = sdhci_ma35_dt_ids,
 306         },
 307         .probe  = ma35_probe,
 308         .remove = ma35_remove,
 309 };
 310 module_platform_driver(sdhci_ma35_driver);
 311
 312 MODULE_DESCRIPTION("SDHCI platform driver for Nuvoton MA35");
 313 MODULE_AUTHOR("Shan-Chun Hung <[email protected]>");
 314 MODULE_LICENSE("GPL");