[PATCH 2/2] mmc: sdhci-of-ma35d1: Add Novoton MA35D1 SDHCI driver

[Shan-Chun Hung <shanchun1218@gmail.com>]

This adds the SDHCI driver for the MA35 series SoC. It is based upon the
SDHCI interface, but requires some extra initialization.

Signed-off-by: schung <schung@nuvoton.com>
---
 drivers/mmc/host/Kconfig           |  13 ++
 drivers/mmc/host/Makefile          |   1 +
 drivers/mmc/host/sdhci-of-ma35d1.c | 297 +++++++++++++++++++++++++++++
 3 files changed, 311 insertions(+)
 create mode 100644 drivers/mmc/host/sdhci-of-ma35d1.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index bb0d4fb0892a..e993901ebedd 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -252,6 +252,19 @@ config MMC_SDHCI_OF_SPARX5

	  If unsure, say N.

+config MMC_SDHCI_OF_MA35D1
+	tristate "SDHCI OF support for the MA35D1 SDHCI controller"
+	depends on ARCH_A35 || COMPILE_TEST
+	depends on MMC_SDHCI_PLTFM
+	depends on OF && COMMON_CLK
+	help
+	  This selects the MA35D1 Secure Digital Host Controller Interface.
+
+	  If you have a controller with this interface, say Y or M here. You
+	  also need to enable an appropriate bus interface.
+
+	  If unsure, say N.
+
 config MMC_SDHCI_CADENCE
	tristate "SDHCI support for the Cadence SD/SDIO/eMMC controller"
	depends on MMC_SDHCI_PLTFM
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index f53f86d200ac..3ccffebbe59b 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_MMC_SDHCI_OF_ESDHC)	+= sdhci-of-esdhc.o
 obj-$(CONFIG_MMC_SDHCI_OF_HLWD)		+= sdhci-of-hlwd.o
 obj-$(CONFIG_MMC_SDHCI_OF_DWCMSHC)	+= sdhci-of-dwcmshc.o
 obj-$(CONFIG_MMC_SDHCI_OF_SPARX5)	+= sdhci-of-sparx5.o
+obj-$(CONFIG_MMC_SDHCI_OF_MA35D1)	+= sdhci-of-ma35d1.o
 obj-$(CONFIG_MMC_SDHCI_BCM_KONA)	+= sdhci-bcm-kona.o
 obj-$(CONFIG_MMC_SDHCI_IPROC)		+= sdhci-iproc.o
 obj-$(CONFIG_MMC_SDHCI_NPCM)		+= sdhci-npcm.o
diff --git a/drivers/mmc/host/sdhci-of-ma35d1.c b/drivers/mmc/host/sdhci-of-ma35d1.c
new file mode 100644
index 000000000000..7714a5ab463d
--- /dev/null
+++ b/drivers/mmc/host/sdhci-of-ma35d1.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ *
+ * Author: Shan-Chun Hung <shanchun1218@gmail.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/mmc/mmc.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include "sdhci-pltfm.h"
+
+#define MA35_SYS_MISCFCR0	0x070
+#define MA35_SDHCI_MSHCCTL	0x508
+#define MA35_SDHCI_MBIUCTL	0x510
+
+#define MA35_SDHCI_CMD_CONFLICT_CHK	BIT(0)
+#define MA35_SDHCI_INCR_MSK		GENMASK(3, 0)
+#define MA35_SDHCI_INCR16		BIT(3)
+#define MA35_SDHCI_INCR8		BIT(2)
+
+#define BOUNDARY_OK(addr, len) \
+	((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))
+
+struct ma35_priv {
+	struct regmap		*regmap;
+	struct reset_control	*rst;
+	struct pinctrl		*pinctrl;
+	struct pinctrl_state	*pins_uhs;
+	struct pinctrl_state	*pins_default;
+};
+
+struct ma35_restore_data {
+	u32	reg;
+	u32	width;
+};
+
+static const struct ma35_restore_data restore_data[] = {
+	{ SDHCI_CLOCK_CONTROL,		32},
+	{ SDHCI_BLOCK_SIZE,		32},
+	{ SDHCI_INT_ENABLE,		32},
+	{ SDHCI_SIGNAL_ENABLE,		32},
+	{ SDHCI_AUTO_CMD_STATUS,	32},
+	{ SDHCI_HOST_CONTROL,		32},
+	{ SDHCI_TIMEOUT_CONTROL,	 8},
+	{ MA35_SDHCI_MSHCCTL,		32},
+	{ MA35_SDHCI_MBIUCTL,		32},
+};
+
+/*
+ * If DMA addr spans 128MB boundary, we split the DMA transfer into two
+ * so that each DMA transfer doesn't exceed the boundary.
+ */
+static void ma35_adma_write_desc(struct sdhci_host *host, void **desc,
+				  dma_addr_t addr, int len, unsigned int cmd)
+{
+	int tmplen, offset;
+
+	if (likely(!len || BOUNDARY_OK(addr, len))) {
+		sdhci_adma_write_desc(host, desc, addr, len, cmd);
+		return;
+	}
+
+	offset = addr & (SZ_128M - 1);
+	tmplen = SZ_128M - offset;
+	sdhci_adma_write_desc(host, desc, addr, tmplen, cmd);
+
+	addr += tmplen;
+	len -= tmplen;
+	sdhci_adma_write_desc(host, desc, addr, len, cmd);
+}
+
+static void ma35_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+	u32 ctl;
+
+	/* If the clock frequency exceeds MMC_HIGH_52_MAX_DTR,
+	 *	disable command conflict check.
+	 */
+	ctl = sdhci_readw(host, MA35_SDHCI_MSHCCTL);
+	if (clock > MMC_HIGH_52_MAX_DTR)
+		ctl &= ~MA35_SDHCI_CMD_CONFLICT_CHK;
+	else
+		ctl |= MA35_SDHCI_CMD_CONFLICT_CHK;
+	sdhci_writew(host, ctl, MA35_SDHCI_MSHCCTL);
+
+	sdhci_set_clock(host, clock);
+}
+
+static int ma35_start_signal_voltage_switch(struct mmc_host *mmc,
+					      struct mmc_ios *ios)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct ma35_priv *priv = sdhci_pltfm_priv(pltfm_host);
+
+	switch (ios->signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_180:
+		if (!IS_ERR(priv->pinctrl) && !IS_ERR(priv->pins_uhs))
+			pinctrl_select_state(priv->pinctrl, priv->pins_uhs);
+		break;
+	case MMC_SIGNAL_VOLTAGE_330:
+		if (!IS_ERR(priv->pinctrl) && !IS_ERR(priv->pins_default))
+			pinctrl_select_state(priv->pinctrl, priv->pins_default);
+		break;
+	default:
+		dev_err(mmc_dev(host->mmc), "Unsupported signal voltage!\n");
+		return -EINVAL;
+	}
+
+	return sdhci_start_signal_voltage_switch(mmc, ios);
+}
+
+static void ma35_voltage_switch(struct sdhci_host *host)
+{
+	/* Wait for 5ms after set 1.8V signal enable bit */
+	usleep_range(5000, 5500);
+}
+
+static int ma35_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct ma35_priv *priv = sdhci_pltfm_priv(pltfm_host);
+
+	/* Limitations require a reset SD/eMMC before tuning. */
+	if (!IS_ERR(priv->rst)) {
+		int idx;
+		u32 *val;
+
+		val = kmalloc(ARRAY_SIZE(restore_data), GFP_KERNEL);
+		for (idx = 0; idx < ARRAY_SIZE(restore_data); idx++) {
+			if (restore_data[idx].width == 32)
+				val[idx] = sdhci_readl(host, restore_data[idx].reg);
+			else if (restore_data[idx].width == 8)
+				val[idx] = sdhci_readb(host, restore_data[idx].reg);
+		}
+
+		reset_control_assert(priv->rst);
+		reset_control_deassert(priv->rst);
+
+		for (idx = 0; idx < ARRAY_SIZE(restore_data); idx++) {
+			if (restore_data[idx].width == 32)
+				sdhci_writel(host, val[idx], restore_data[idx].reg);
+			else if (restore_data[idx].width == 8)
+				sdhci_writeb(host, val[idx], restore_data[idx].reg);
+		}
+
+		kfree(val);
+	}
+
+	return sdhci_execute_tuning(mmc, opcode);
+}
+
+static const struct sdhci_ops sdhci_ma35_ops = {
+	.set_clock		= ma35_set_clock,
+	.set_bus_width		= sdhci_set_bus_width,
+	.set_uhs_signaling	= sdhci_set_uhs_signaling,
+	.get_max_clock		= sdhci_pltfm_clk_get_max_clock,
+	.reset			= sdhci_reset,
+	.adma_write_desc	= ma35_adma_write_desc,
+	.voltage_switch	= ma35_voltage_switch,
+};
+
+static const struct sdhci_pltfm_data sdhci_ma35_pdata = {
+	.ops = &sdhci_ma35_ops,
+	.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
+	.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN | SDHCI_QUIRK2_BROKEN_DDR50 |
+		   SDHCI_QUIRK2_ACMD23_BROKEN,
+};
+
+static int ma35_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sdhci_pltfm_host *pltfm_host;
+	struct sdhci_host *host;
+	struct ma35_priv *priv;
+	int err;
+	u32 extra, ctl;
+
+	host = sdhci_pltfm_init(pdev, &sdhci_ma35_pdata,
+				sizeof(struct ma35_priv));
+	if (IS_ERR(host))
+		return PTR_ERR(host);
+
+	/*
+	 * extra adma table cnt for cross 128M boundary handling.
+	 */
+	extra = DIV_ROUND_UP_ULL(dma_get_required_mask(&pdev->dev), SZ_128M);
+	if (extra > SDHCI_MAX_SEGS)
+		extra = SDHCI_MAX_SEGS;
+	host->adma_table_cnt += extra;
+	pltfm_host = sdhci_priv(host);
+	priv = sdhci_pltfm_priv(pltfm_host);
+
+	if (dev->of_node) {
+		pltfm_host->clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(pltfm_host->clk)) {
+			err = PTR_ERR(pltfm_host->clk);
+			dev_err(&pdev->dev, "failed to get clk: %d\n", err);
+			goto free_pltfm;
+		}
+		err = clk_prepare_enable(pltfm_host->clk);
+		if (err)
+			goto free_pltfm;
+	}
+
+	err = mmc_of_parse(host->mmc);
+	if (err)
+		goto err_clk;
+
+	priv->rst = devm_reset_control_get(&pdev->dev, NULL);
+
+	sdhci_get_of_property(pdev);
+
+	priv->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (!IS_ERR(priv->pinctrl)) {
+		priv->pins_default = pinctrl_lookup_state(priv->pinctrl, "default");
+		priv->pins_uhs = pinctrl_lookup_state(priv->pinctrl, "state_uhs");
+		pinctrl_select_state(priv->pinctrl, priv->pins_default);
+	}
+
+	if (!(host->quirks2 & SDHCI_QUIRK2_NO_1_8_V)) {
+		u32 reg;
+
+		priv->regmap = syscon_regmap_lookup_by_phandle(
+				pdev->dev.of_node, "nuvoton,sys");
+
+		if (!IS_ERR(priv->regmap)) {
+			/* Enable SDHCI voltage stable for 1.8V */
+			regmap_read(priv->regmap, MA35_SYS_MISCFCR0, &reg);
+			reg |= BIT(17);
+			regmap_write(priv->regmap, MA35_SYS_MISCFCR0, reg);
+		}
+
+		host->mmc_host_ops.start_signal_voltage_switch =
+					ma35_start_signal_voltage_switch;
+	}
+
+	host->mmc_host_ops.execute_tuning = ma35_execute_tuning;
+
+	err = sdhci_add_host(host);
+	if (err)
+		goto err_clk;
+
+	/* Enable INCR16 and INCR8 */
+	ctl = sdhci_readw(host, MA35_SDHCI_MBIUCTL);
+	ctl &= ~MA35_SDHCI_INCR_MSK;
+	ctl |= MA35_SDHCI_INCR16|MA35_SDHCI_INCR8;
+	sdhci_writew(host, ctl, MA35_SDHCI_MBIUCTL);
+
+	return 0;
+
+err_clk:
+	clk_disable_unprepare(pltfm_host->clk);
+
+free_pltfm:
+	sdhci_pltfm_free(pdev);
+	return err;
+}
+
+static int ma35_remove(struct platform_device *pdev)
+{
+	struct sdhci_host *host = platform_get_drvdata(pdev);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	sdhci_remove_host(host, 0);
+	clk_disable_unprepare(pltfm_host->clk);
+	sdhci_pltfm_free(pdev);
+
+	return 0;
+}
+
+static const struct of_device_id sdhci_ma35_dt_ids[] = {
+	{ .compatible = "nuvoton,ma35d1-sdhci" },
+	{}
+};
+
+static struct platform_driver sdhci_ma35_driver = {
+	.driver	= {
+		.name	= "sdhci-ma35",
+		.of_match_table = sdhci_ma35_dt_ids,
+	},
+	.probe	= ma35_probe,
+	.remove = ma35_remove,
+};
+module_platform_driver(sdhci_ma35_driver);
+
+MODULE_DESCRIPTION("SDHCI platform driver for Nuvoton ma35d1");
+MODULE_AUTHOR("shanchun1218@google.com");
+MODULE_LICENSE("GPL v2");
--
2.25.1