--- /dev/null
+/*
+ * Copyright (C) 2016 Socionext Inc.
+ * Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mmc/host.h>
+
+#include "sdhci-pltfm.h"
+
+/* HRS - Host Register Set (specific to Cadence) */
+#define SDHCI_CDNS_HRS04 0x10 /* PHY access port */
+#define SDHCI_CDNS_HRS04_ACK BIT(26)
+#define SDHCI_CDNS_HRS04_RD BIT(25)
+#define SDHCI_CDNS_HRS04_WR BIT(24)
+#define SDHCI_CDNS_HRS04_RDATA_SHIFT 12
+#define SDHCI_CDNS_HRS04_WDATA_SHIFT 8
+#define SDHCI_CDNS_HRS04_ADDR_SHIFT 0
+
+#define SDHCI_CDNS_HRS06 0x18 /* eMMC control */
+#define SDHCI_CDNS_HRS06_TUNE_UP BIT(15)
+#define SDHCI_CDNS_HRS06_TUNE_SHIFT 8
+#define SDHCI_CDNS_HRS06_TUNE_MASK 0x3f
+#define SDHCI_CDNS_HRS06_MODE_MASK 0x7
+#define SDHCI_CDNS_HRS06_MODE_SD 0x0
+#define SDHCI_CDNS_HRS06_MODE_MMC_SDR 0x2
+#define SDHCI_CDNS_HRS06_MODE_MMC_DDR 0x3
+#define SDHCI_CDNS_HRS06_MODE_MMC_HS200 0x4
+#define SDHCI_CDNS_HRS06_MODE_MMC_HS400 0x5
+
+/* SRS - Slot Register Set (SDHCI-compatible) */
+#define SDHCI_CDNS_SRS_BASE 0x200
+
+/* PHY */
+#define SDHCI_CDNS_PHY_DLY_SD_HS 0x00
+#define SDHCI_CDNS_PHY_DLY_SD_DEFAULT 0x01
+#define SDHCI_CDNS_PHY_DLY_UHS_SDR12 0x02
+#define SDHCI_CDNS_PHY_DLY_UHS_SDR25 0x03
+#define SDHCI_CDNS_PHY_DLY_UHS_SDR50 0x04
+#define SDHCI_CDNS_PHY_DLY_UHS_DDR50 0x05
+#define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY 0x06
+#define SDHCI_CDNS_PHY_DLY_EMMC_SDR 0x07
+#define SDHCI_CDNS_PHY_DLY_EMMC_DDR 0x08
+
+/*
+ * The tuned val register is 6 bit-wide, but not the whole of the range is
+ * available. The range 0-42 seems to be available (then 43 wraps around to 0)
+ * but I am not quite sure if it is official. Use only 0 to 39 for safety.
+ */
+#define SDHCI_CDNS_MAX_TUNING_LOOP 40
+
+struct sdhci_cdns_priv {
+ void __iomem *hrs_addr;
+};
+
+static void sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
+ u8 addr, u8 data)
+{
+ void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04;
+ u32 tmp;
+
+ tmp = (data << SDHCI_CDNS_HRS04_WDATA_SHIFT) |
+ (addr << SDHCI_CDNS_HRS04_ADDR_SHIFT);
+ writel(tmp, reg);
+
+ tmp |= SDHCI_CDNS_HRS04_WR;
+ writel(tmp, reg);
+
+ tmp &= ~SDHCI_CDNS_HRS04_WR;
+ writel(tmp, reg);
+}
+
+static void sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
+{
+ sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_SD_HS, 4);
+ sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_SD_DEFAULT, 4);
+ sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_LEGACY, 9);
+ sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_SDR, 2);
+ sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_DDR, 3);
+}
+
+static inline void *sdhci_cdns_priv(struct sdhci_host *host)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+ return sdhci_pltfm_priv(pltfm_host);
+}
+
+static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
+{
+ /*
+ * Cadence's spec says the Timeout Clock Frequency is the same as the
+ * Base Clock Frequency. Divide it by 1000 to return a value in kHz.
+ */
+ return host->max_clk / 1000;
+}
+
+static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
+ unsigned int timing)
+{
+ struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
+ u32 mode, tmp;
+
+ switch (timing) {
+ case MMC_TIMING_MMC_HS:
+ mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR;
+ break;
+ case MMC_TIMING_MMC_DDR52:
+ mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR;
+ break;
+ case MMC_TIMING_MMC_HS200:
+ mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
+ break;
+ case MMC_TIMING_MMC_HS400:
+ mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
+ break;
+ default:
+ mode = SDHCI_CDNS_HRS06_MODE_SD;
+ break;
+ }
+
+ /* The speed mode for eMMC is selected by HRS06 register */
+ tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
+ tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK;
+ tmp |= mode;
+ writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
+
+ /* For SD, fall back to the default handler */
+ if (mode == SDHCI_CDNS_HRS06_MODE_SD)
+ sdhci_set_uhs_signaling(host, timing);
+}
+
+static const struct sdhci_ops sdhci_cdns_ops = {
+ .set_clock = sdhci_set_clock,
+ .get_timeout_clock = sdhci_cdns_get_timeout_clock,
+ .set_bus_width = sdhci_set_bus_width,
+ .reset = sdhci_reset,
+ .set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
+};
+
+static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
+ .ops = &sdhci_cdns_ops,
+};
+
+static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
+{
+ struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
+ void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
+ u32 tmp;
+
+ if (WARN_ON(val > SDHCI_CDNS_HRS06_TUNE_MASK))
+ return -EINVAL;
+
+ tmp = readl(reg);
+ tmp &= ~(SDHCI_CDNS_HRS06_TUNE_MASK << SDHCI_CDNS_HRS06_TUNE_SHIFT);
+ tmp |= val << SDHCI_CDNS_HRS06_TUNE_SHIFT;
+ tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
+ writel(tmp, reg);
+
+ return readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
+ 0, 1);
+}
+
+static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ int cur_streak = 0;
+ int max_streak = 0;
+ int end_of_streak = 0;
+ int i;
+
+ /*
+ * This handler only implements the eMMC tuning that is specific to
+ * this controller. Fall back to the standard method for SD timing.
+ */
+ if (host->timing != MMC_TIMING_MMC_HS200)
+ return sdhci_execute_tuning(mmc, opcode);
+
+ if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200))
+ return -EINVAL;
+
+ for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
+ if (sdhci_cdns_set_tune_val(host, i) ||
+ mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
+ cur_streak = 0;
+ } else { /* good */
+ cur_streak++;
+ if (cur_streak > max_streak) {
+ max_streak = cur_streak;
+ end_of_streak = i;
+ }
+ }
+ }
+
+ if (!max_streak) {
+ dev_err(mmc_dev(host->mmc), "no tuning point found\n");
+ return -EIO;
+ }
+
+ return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
+}
+
+static int sdhci_cdns_probe(struct platform_device *pdev)
+{
+ struct sdhci_host *host;
+ struct sdhci_pltfm_host *pltfm_host;
+ struct sdhci_cdns_priv *priv;
+ struct clk *clk;
+ int ret;
+
+ clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ ret = clk_prepare_enable(clk);
+ if (ret)
+ return ret;
+
+ host = sdhci_pltfm_init(pdev, &sdhci_cdns_pltfm_data, sizeof(*priv));
+ if (IS_ERR(host)) {
+ ret = PTR_ERR(host);
+ goto disable_clk;
+ }
+
+ pltfm_host = sdhci_priv(host);
+ pltfm_host->clk = clk;
+
+ priv = sdhci_cdns_priv(host);
+ priv->hrs_addr = host->ioaddr;
+ host->ioaddr += SDHCI_CDNS_SRS_BASE;
+ host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
+
+ ret = mmc_of_parse(host->mmc);
+ if (ret)
+ goto free;
+
+ sdhci_cdns_phy_init(priv);
+
+ ret = sdhci_add_host(host);
+ if (ret)
+ goto free;
+
+ return 0;
+free:
+ sdhci_pltfm_free(pdev);
+disable_clk:
+ clk_disable_unprepare(clk);
+
+ return ret;
+}
+
+static const struct of_device_id sdhci_cdns_match[] = {
+ { .compatible = "cdns,sd4hc" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
+
+static struct platform_driver sdhci_cdns_driver = {
+ .driver = {
+ .name = "sdhci-cdns",
+ .pm = &sdhci_pltfm_pmops,
+ .of_match_table = sdhci_cdns_match,
+ },
+ .probe = sdhci_cdns_probe,
+ .remove = sdhci_pltfm_unregister,
+};
+module_platform_driver(sdhci_cdns_driver);
+
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
+MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver");
+MODULE_LICENSE("GPL");
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