nand: brcmnand: add iproc support

Add support for the iproc Broadcom NAND controller,
used in Northstar SoCs for example. Based on the Linux
driver.

Cc: Philippe Reynes <philippe.reynes@softathome.com>
Cc: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: William Zhang <william.zhang@broadcom.com>
Link: https://lore.kernel.org/all/20230308214231.378013-1-linus.walleij@linaro.org/
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 5c7b0d9..d115fcf 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -156,6 +156,13 @@
        help
          Enable support for broadcom nand driver on bcm63158.
 
+config NAND_BRCMNAND_IPROC
+       bool "Support Broadcom NAND controller on the iproc family"
+       depends on NAND_BRCMNAND
+       help
+         Enable support for broadcom nand driver on the Broadcom
+         iproc family such as Northstar (BCM5301x, BCM4708...)
+
 config NAND_DAVINCI
 	bool "Support TI Davinci NAND controller"
 	select SYS_NAND_SELF_INIT if TARGET_DA850EVM
diff --git a/drivers/mtd/nand/raw/brcmnand/Makefile b/drivers/mtd/nand/raw/brcmnand/Makefile
index f46a7ed..0c6325a 100644
--- a/drivers/mtd/nand/raw/brcmnand/Makefile
+++ b/drivers/mtd/nand/raw/brcmnand/Makefile
@@ -6,5 +6,6 @@
 obj-$(CONFIG_NAND_BRCMNAND_68360) += bcm68360_nand.o
 obj-$(CONFIG_NAND_BRCMNAND_6838) += bcm6838_nand.o
 obj-$(CONFIG_NAND_BRCMNAND_6858) += bcm6858_nand.o
+obj-$(CONFIG_NAND_BRCMNAND_IPROC) += iproc_nand.o
 obj-$(CONFIG_NAND_BRCMNAND) += brcmnand.o
 obj-$(CONFIG_NAND_BRCMNAND) += brcmnand_compat.o
diff --git a/drivers/mtd/nand/raw/brcmnand/iproc_nand.c b/drivers/mtd/nand/raw/brcmnand/iproc_nand.c
new file mode 100644
index 0000000..69711d9
--- /dev/null
+++ b/drivers/mtd/nand/raw/brcmnand/iproc_nand.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Code borrowed from the Linux driver
+ * Copyright (C) 2015 Broadcom Corporation
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <memalign.h>
+#include <nand.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <dm.h>
+
+#include "brcmnand.h"
+
+struct iproc_nand_soc {
+	struct brcmnand_soc soc;
+	void __iomem *idm_base;
+	void __iomem *ext_base;
+};
+
+#define IPROC_NAND_CTLR_READY_OFFSET	0x10
+#define IPROC_NAND_CTLR_READY		BIT(0)
+
+#define IPROC_NAND_IO_CTRL_OFFSET	0x00
+#define IPROC_NAND_APB_LE_MODE		BIT(24)
+#define IPROC_NAND_INT_CTRL_READ_ENABLE	BIT(6)
+
+static bool iproc_nand_intc_ack(struct brcmnand_soc *soc)
+{
+	struct iproc_nand_soc *priv =
+			container_of(soc, struct iproc_nand_soc, soc);
+	void __iomem *mmio = priv->ext_base + IPROC_NAND_CTLR_READY_OFFSET;
+	u32 val = brcmnand_readl(mmio);
+
+	if (val & IPROC_NAND_CTLR_READY) {
+		brcmnand_writel(IPROC_NAND_CTLR_READY, mmio);
+		return true;
+	}
+
+	return false;
+}
+
+static void iproc_nand_intc_set(struct brcmnand_soc *soc, bool en)
+{
+	struct iproc_nand_soc *priv =
+			container_of(soc, struct iproc_nand_soc, soc);
+	void __iomem *mmio = priv->idm_base + IPROC_NAND_IO_CTRL_OFFSET;
+	u32 val = brcmnand_readl(mmio);
+
+	if (en)
+		val |= IPROC_NAND_INT_CTRL_READ_ENABLE;
+	else
+		val &= ~IPROC_NAND_INT_CTRL_READ_ENABLE;
+
+	brcmnand_writel(val, mmio);
+}
+
+static void iproc_nand_apb_access(struct brcmnand_soc *soc, bool prepare,
+				  bool is_param)
+{
+	struct iproc_nand_soc *priv =
+		container_of(soc, struct iproc_nand_soc, soc);
+	void __iomem *mmio = priv->idm_base + IPROC_NAND_IO_CTRL_OFFSET;
+	u32 val;
+
+	val = brcmnand_readl(mmio);
+
+	/*
+	 * In the case of BE or when dealing with NAND data, always configure
+	 * the APB bus to LE mode before accessing the FIFO and back to BE mode
+	 * after the access is done
+	 */
+	if (IS_ENABLED(CONFIG_SYS_BIG_ENDIAN) || !is_param) {
+		if (prepare)
+			val |= IPROC_NAND_APB_LE_MODE;
+		else
+			val &= ~IPROC_NAND_APB_LE_MODE;
+	} else { /* when in LE accessing the parameter page, keep APB in BE */
+		val &= ~IPROC_NAND_APB_LE_MODE;
+	}
+
+	brcmnand_writel(val, mmio);
+}
+
+static int iproc_nand_probe(struct udevice *dev)
+{
+	struct udevice *pdev = dev;
+	struct iproc_nand_soc *priv = dev_get_priv(dev);
+	struct brcmnand_soc *soc;
+	struct resource res;
+	int ret;
+
+	soc = &priv->soc;
+
+	ret = dev_read_resource_byname(pdev, "iproc-idm", &res);
+	if (ret)
+		return ret;
+
+	priv->idm_base = devm_ioremap(dev, res.start, resource_size(&res));
+	if (IS_ERR(priv->idm_base))
+		return PTR_ERR(priv->idm_base);
+
+	ret = dev_read_resource_byname(pdev, "iproc-ext", &res);
+	if (ret)
+		return ret;
+
+	priv->ext_base = devm_ioremap(dev, res.start, resource_size(&res));
+	if (IS_ERR(priv->ext_base))
+		return PTR_ERR(priv->ext_base);
+
+	soc->ctlrdy_ack = iproc_nand_intc_ack;
+	soc->ctlrdy_set_enabled = iproc_nand_intc_set;
+	soc->prepare_data_bus = iproc_nand_apb_access;
+
+	return brcmnand_probe(pdev, soc);
+}
+
+static const struct udevice_id iproc_nand_dt_ids[] = {
+	{
+		.compatible = "brcm,nand-iproc",
+	},
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(iproc_nand) = {
+	.name = "iproc-nand",
+	.id = UCLASS_MTD,
+	.of_match = iproc_nand_dt_ids,
+	.probe = iproc_nand_probe,
+	.priv_auto = sizeof(struct iproc_nand_soc),
+};
+
+void board_nand_init(void)
+{
+	struct udevice *dev;
+	int ret;
+
+	ret = uclass_get_device_by_driver(UCLASS_MTD,
+					  DM_DRIVER_GET(iproc_nand), &dev);
+	if (ret && ret != -ENODEV)
+		pr_err("Failed to initialize %s. (error %d)\n", dev->name,
+		       ret);
+}