mmc: sdhci-cadence: add Cadence SD4HC support

Add a driver for the Cadence SD4HC SD/SDIO/eMMC Controller.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/mmc/sdhci-cadence.c b/drivers/mmc/sdhci-cadence.c
new file mode 100644
index 0000000..2253bbc
--- /dev/null
+++ b/drivers/mmc/sdhci-cadence.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2016 Socionext Inc.
+ *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <linux/io.h>
+#include <linux/sizes.h>
+#include <dm/device.h>
+#include <mmc.h>
+#include <sdhci.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
+
+/* 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
+
+struct sdhci_cdns_plat {
+	struct mmc_config cfg;
+	struct mmc mmc;
+	void __iomem *hrs_addr;
+};
+
+static void sdhci_cdns_write_phy_reg(struct sdhci_cdns_plat *plat,
+				     u8 addr, u8 data)
+{
+	void __iomem *reg = plat->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_plat *plat)
+{
+	sdhci_cdns_write_phy_reg(plat, SDHCI_CDNS_PHY_DLY_SD_HS, 4);
+	sdhci_cdns_write_phy_reg(plat, SDHCI_CDNS_PHY_DLY_SD_DEFAULT, 4);
+	sdhci_cdns_write_phy_reg(plat, SDHCI_CDNS_PHY_DLY_EMMC_LEGACY, 9);
+	sdhci_cdns_write_phy_reg(plat, SDHCI_CDNS_PHY_DLY_EMMC_SDR, 2);
+	sdhci_cdns_write_phy_reg(plat, SDHCI_CDNS_PHY_DLY_EMMC_DDR, 3);
+}
+
+static int sdhci_cdns_bind(struct udevice *dev)
+{
+	struct sdhci_cdns_plat *plat = dev_get_platdata(dev);
+
+	return sdhci_bind(dev, &plat->mmc, &plat->cfg);
+}
+
+static int sdhci_cdns_probe(struct udevice *dev)
+{
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct sdhci_cdns_plat *plat = dev_get_platdata(dev);
+	struct sdhci_host *host = dev_get_priv(dev);
+	fdt_addr_t base;
+	int ret;
+
+	base = dev_get_addr(dev);
+	if (base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	plat->hrs_addr = devm_ioremap(dev, base, SZ_1K);
+	if (!plat->hrs_addr)
+		return -ENOMEM;
+
+	host->name = dev->name;
+	host->ioaddr = plat->hrs_addr + SDHCI_CDNS_SRS_BASE;
+	host->quirks |= SDHCI_QUIRK_WAIT_SEND_CMD;
+
+	sdhci_cdns_phy_init(plat);
+
+	ret = sdhci_setup_cfg(&plat->cfg, host, 0, 0);
+	if (ret)
+		return ret;
+
+	upriv->mmc = &plat->mmc;
+	host->mmc = &plat->mmc;
+	host->mmc->priv = host;
+
+	return sdhci_probe(dev);
+}
+
+static const struct udevice_id sdhci_cdns_match[] = {
+	{ .compatible = "socionext,uniphier-sd4hc" },
+	{ .compatible = "cdns,sd4hc" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(sdhci_cdns) = {
+	.name = "sdhci-cdns",
+	.id = UCLASS_MMC,
+	.of_match = sdhci_cdns_match,
+	.bind = sdhci_cdns_bind,
+	.probe = sdhci_cdns_probe,
+	.priv_auto_alloc_size = sizeof(struct sdhci_host),
+	.platdata_auto_alloc_size = sizeof(struct sdhci_cdns_plat),
+	.ops = &sdhci_ops,
+};