// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright © 2015 Broadcom Corporation
 */

#include <linux/device.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include "brcmnand.h"

struct iproc_nand_soc {
        struct brcmnand_soc soc;

        void __iomem *idm_base;
        void __iomem *ext_base;
        spinlock_t idm_lock;
};

#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;
        unsigned long flags;

        spin_lock_irqsave(&priv->idm_lock, flags);

        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);

        spin_unlock_irqrestore(&priv->idm_lock, flags);
}

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;
        unsigned long flags;

        spin_lock_irqsave(&priv->idm_lock, flags);

        val = brcmnand_readl(mmio);

        /*
         * In the case of BE or when dealing with NAND data, alway 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_CPU_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);

        spin_unlock_irqrestore(&priv->idm_lock, flags);
}

static int iproc_nand_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct iproc_nand_soc *priv;
        struct brcmnand_soc *soc;

        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;
        soc = &priv->soc;

        spin_lock_init(&priv->idm_lock);

        priv->idm_base = devm_platform_ioremap_resource_byname(pdev, "iproc-idm");
        if (IS_ERR(priv->idm_base))
                return PTR_ERR(priv->idm_base);

        priv->ext_base = devm_platform_ioremap_resource_byname(pdev, "iproc-ext");
        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 of_device_id iproc_nand_of_match[] = {
        { .compatible = "brcm,nand-iproc" },
        {},
};
MODULE_DEVICE_TABLE(of, iproc_nand_of_match);

static struct platform_driver iproc_nand_driver = {
        .probe                  = iproc_nand_probe,
        .remove                 = brcmnand_remove,
        .driver = {
                .name           = "iproc_nand",
                .pm             = &brcmnand_pm_ops,
                .of_match_table = iproc_nand_of_match,
        }
};
module_platform_driver(iproc_nand_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Brian Norris");
MODULE_AUTHOR("Ray Jui");
MODULE_DESCRIPTION("NAND driver for Broadcom IPROC-based SoCs");