[PATCH RFC 1/6] mci: add driver for Broadcom SDHCI

[Andrei Lalaev <andrey.lalaev@gmail.com>]

This adds support for Broadcom SDHCI controller found on BCM2712
SoCs. The driver was ported from U-Boot.

Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
---
 arch/arm/configs/rpi_v8a_defconfig |   1 +
 drivers/mci/Kconfig                |   5 ++
 drivers/mci/Makefile               |   1 +
 drivers/mci/bcmstb-sdhci.c         | 165 +++++++++++++++++++++++++++++++++++++
 4 files changed, 172 insertions(+)

diff --git a/arch/arm/configs/rpi_v8a_defconfig b/arch/arm/configs/rpi_v8a_defconfig
index c29fe30701e8..90899218b192 100644
--- a/arch/arm/configs/rpi_v8a_defconfig
+++ b/arch/arm/configs/rpi_v8a_defconfig
@@ -92,6 +92,7 @@ CONFIG_USB_GADGET=y
 CONFIG_MCI=y
 CONFIG_MCI_BCM283X=y
 CONFIG_MCI_BCM283X_SDHOST=y
+CONFIG_MCI_BCMSTB=y
 CONFIG_LED=y
 CONFIG_LED_GPIO=y
 CONFIG_LED_GPIO_OF=y
diff --git a/drivers/mci/Kconfig b/drivers/mci/Kconfig
index 2c3365e723a4..eebf85db9f5f 100644
--- a/drivers/mci/Kconfig
+++ b/drivers/mci/Kconfig
@@ -154,6 +154,11 @@ config MCI_BCM283X_SDHOST
 	depends on ARCH_BCM283X || COMPILE_TEST
 	select MCI_SDHCI
 
+config MCI_BCMSTB
+	bool "MCI support for BCMSTB"
+	depends on ARCH_BCM283X || COMPILE_TEST
+	select MCI_SDHCI
+
 config MCI_DOVE
 	bool "Marvell Dove SDHCI"
 	depends on ARCH_DOVE || COMPILE_TEST
diff --git a/drivers/mci/Makefile b/drivers/mci/Makefile
index 761f4187c079..eca997dccbd3 100644
--- a/drivers/mci/Makefile
+++ b/drivers/mci/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_MCI_ATMEL_SDHCI)	+= atmel-sdhci.o atmel-sdhci-common.o
 obj-$(CONFIG_MCI_BCM283X)	+= mci-bcm2835.o
 obj-$(CONFIG_MCI_BCM283X_SDHOST)	+= bcm2835-sdhost.o
 obj-$(CONFIG_MCI_CADENCE_SDHCI) += cadence-sdhci.o cadence-sdhci6.o
+obj-$(CONFIG_MCI_BCMSTB)	+= bcmstb-sdhci.o
 obj-$(CONFIG_MCI_DOVE)		+= dove-sdhci.o
 pbl-$(CONFIG_MCI_ATMEL_PBL)	+= atmel_mci_pbl.o atmel_mci_common.o
 pbl-$(CONFIG_MCI_ATMEL_SDHCI_PBL)	+= atmel-sdhci-pbl.o atmel-sdhci-common.o
diff --git a/drivers/mci/bcmstb-sdhci.c b/drivers/mci/bcmstb-sdhci.c
new file mode 100644
index 000000000000..f1275a8936ea
--- /dev/null
+++ b/drivers/mci/bcmstb-sdhci.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * This code is ported from U-Boot by Andrei Lalaev <andrey.lalaev@gmail.com>
+ *
+ * The original code has the following copyright:
+ * (C) Copyright 2018  Cisco Systems, Inc.
+ * (C) Copyright 2019  Synamedia
+ *
+ * Author: Thomas Fitzsimmons <fitzsim@fitzsim.org>
+ */
+
+#include <common.h>
+#include <init.h>
+#include <mci.h>
+#include <malloc.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+#include "sdhci.h"
+
+#define BCMSTB_SDHCI_MAXIMUM_CLOCK_FREQUENCY	52000000
+#define BCMSTB_SDHCI_MINIMUM_CLOCK_FREQUENCY	400000
+
+#define SDIO_CFG_CTRL				0x0
+#define  SDIO_CFG_CTRL_SDCD_N_TEST_EN		BIT(31)
+#define  SDIO_CFG_CTRL_SDCD_N_TEST_LEV		BIT(30)
+
+#define SDIO_CFG_SD_PIN_SEL			0x44
+#define  SDIO_CFG_SD_PIN_SEL_MASK		0x3
+#define  SDIO_CFG_SD_PIN_SEL_CARD		BIT(1)
+
+struct sdhci_bcmstb_mci_host {
+	struct mci_host mci;
+	void __iomem *cfg_regs;
+	struct sdhci sdhci;
+};
+
+static inline struct sdhci_bcmstb_mci_host *to_sdhci_bcmstb_host(struct mci_host *mci)
+{
+	return container_of(mci, struct sdhci_bcmstb_mci_host, mci);
+}
+
+static int sdhci_brcmstb_init_2712(struct mci_host *mci, struct device *dev)
+{
+	struct sdhci_bcmstb_mci_host *host = to_sdhci_bcmstb_host(mci);
+	u32 reg;
+	int ret;
+
+	ret = sdhci_reset(&host->sdhci, SDHCI_RESET_ALL);
+	if (ret)
+		return ret;
+
+	sdhci_write8(&host->sdhci, SDHCI_POWER_CONTROL,
+		     SDHCI_BUS_VOLTAGE_330 | SDHCI_BUS_POWER_EN);
+	udelay(400);
+
+	sdhci_write32(&host->sdhci, SDHCI_INT_ENABLE, SDHCI_INT_DATA_MASK | SDHCI_INT_CMD_MASK);
+	sdhci_write32(&host->sdhci, SDHCI_SIGNAL_ENABLE, 0x00);
+
+	if (host->mci.host_caps & MMC_CAP_NONREMOVABLE) {
+		/* Force presence */
+		reg = readl(host->cfg_regs + SDIO_CFG_CTRL);
+		reg &= ~SDIO_CFG_CTRL_SDCD_N_TEST_LEV;
+		reg |= SDIO_CFG_CTRL_SDCD_N_TEST_EN;
+		writel(reg, host->cfg_regs + SDIO_CFG_CTRL);
+	} else {
+		/* Enable card detection line */
+		reg = readl(host->cfg_regs + SDIO_CFG_SD_PIN_SEL);
+		reg &= ~SDIO_CFG_SD_PIN_SEL_MASK;
+		reg |= SDIO_CFG_SD_PIN_SEL_CARD;
+		writel(reg, host->cfg_regs + SDIO_CFG_SD_PIN_SEL);
+	}
+
+	return 0;
+}
+
+static void sdhci_brcmstb_set_ios(struct mci_host *mci, struct mci_ios *ios)
+{
+	struct sdhci_bcmstb_mci_host *host = to_sdhci_bcmstb_host(mci);
+
+	if (ios->clock)
+		sdhci_set_clock(&host->sdhci, ios->clock, host->sdhci.max_clk);
+	sdhci_set_bus_width(&host->sdhci, ios->bus_width);
+}
+
+static int sdhci_brcmstb_send_cmd(struct mci_host *mci, struct mci_cmd *cmd)
+{
+	struct sdhci_bcmstb_mci_host *host = to_sdhci_bcmstb_host(mci);
+
+	return sdhci_send_command(&host->sdhci, cmd);
+}
+
+static int sdhci_brcmstb_execute_tuning(struct mci_host *mci, u32 opcode)
+{
+	struct sdhci_bcmstb_mci_host *host = to_sdhci_bcmstb_host(mci);
+
+	return sdhci_execute_tuning(&host->sdhci, opcode);
+}
+
+static const struct mci_ops bcmstb_sdhci_ops = {
+	.init = sdhci_brcmstb_init_2712,
+	.set_ios = sdhci_brcmstb_set_ios,
+	.send_cmd = sdhci_brcmstb_send_cmd,
+	.execute_tuning = sdhci_brcmstb_execute_tuning,
+};
+
+static int sdhci_bcmstb_probe(struct device *dev)
+{
+	struct sdhci_bcmstb_mci_host *host;
+	struct resource *iores_cfg;
+	struct resource *iores;
+	struct clk *clk;
+	int ret;
+
+	clk = clk_get(dev, NULL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	ret = clk_enable(clk);
+	if (ret)
+		return ret;
+
+	iores = dev_request_mem_resource_by_name(dev, "host");
+	if (IS_ERR(iores))
+		return PTR_ERR(iores);
+
+	iores_cfg = dev_request_mem_resource_by_name(dev, "cfg");
+	if (IS_ERR(iores))
+		return PTR_ERR(iores);
+
+	host = xzalloc(sizeof(*host));
+	host->mci.ops = bcmstb_sdhci_ops;
+	host->mci.hw_dev = dev;
+	host->mci.f_min = BCMSTB_SDHCI_MINIMUM_CLOCK_FREQUENCY;
+	host->mci.f_max = BCMSTB_SDHCI_MAXIMUM_CLOCK_FREQUENCY;
+
+	host->cfg_regs = IOMEM(iores_cfg->start);
+
+	host->sdhci.base = IOMEM(iores->start);
+	host->sdhci.mci = &host->mci;
+
+	mci_of_parse(&host->mci);
+
+	ret = sdhci_setup_host(&host->sdhci);
+	if (ret) {
+		dev_err(dev, "Failed to setup SDHCI host");
+		return ret;
+	}
+
+	return mci_register(&host->mci);
+}
+
+static const struct of_device_id sdhci_bcmstb_compatible[] = {
+	{ .compatible = "brcm,bcm2712-sdhci" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sdhci_bcmstb_match);
+
+static struct driver sdhci_bcmstb_driver = {
+	.name = "sdhci-bcmstb",
+	.probe = sdhci_bcmstb_probe,
+	.of_compatible = DRV_OF_COMPAT(sdhci_bcmstb_compatible),
+};
+
+device_platform_driver(sdhci_bcmstb_driver);

-- 
2.55.0