// 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 bcmbca_nand_soc {
        struct brcmnand_soc soc;
        void __iomem *base;
};

#define BCMBCA_NAND_INT_STATUS          0x00
#define BCMBCA_NAND_INT_EN                      0x04

enum {
        BCMBCA_CTLRDY           = BIT(4),
};

#if defined(CONFIG_ARM64)
#define ALIGN_REQ               8
#else
#define ALIGN_REQ               4
#endif

static inline bool bcmbca_nand_is_buf_aligned(void *flash_cache,  void *buffer)
{
        return IS_ALIGNED((uintptr_t)buffer, ALIGN_REQ) &&
                                IS_ALIGNED((uintptr_t)flash_cache, ALIGN_REQ);
}

static bool bcmbca_nand_intc_ack(struct brcmnand_soc *soc)
{
        struct bcmbca_nand_soc *priv =
                        container_of(soc, struct bcmbca_nand_soc, soc);
        void __iomem *mmio = priv->base + BCMBCA_NAND_INT_STATUS;
        u32 val = brcmnand_readl(mmio);

        if (val & BCMBCA_CTLRDY) {
                brcmnand_writel(val & ~BCMBCA_CTLRDY, mmio);
                return true;
        }

        return false;
}

static void bcmbca_nand_intc_set(struct brcmnand_soc *soc, bool en)
{
        struct bcmbca_nand_soc *priv =
                        container_of(soc, struct bcmbca_nand_soc, soc);
        void __iomem *mmio = priv->base + BCMBCA_NAND_INT_EN;
        u32 val = brcmnand_readl(mmio);

        if (en)
                val |= BCMBCA_CTLRDY;
        else
                val &= ~BCMBCA_CTLRDY;

        brcmnand_writel(val, mmio);
}

static void bcmbca_read_data_bus(struct brcmnand_soc *soc,
                                 void __iomem *flash_cache,  u32 *buffer, int fc_words)
{
        /*
         * memcpy can do unaligned aligned access depending on source
         * and dest address, which is incompatible with nand cache. Fallback
         * to the memcpy_fromio in such case
         */
        if (bcmbca_nand_is_buf_aligned((void __force *)flash_cache, buffer))
                memcpy((void *)buffer, (void __force *)flash_cache, fc_words * 4);
        else
                memcpy_fromio((void *)buffer, flash_cache, fc_words * 4);
}

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

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

        priv->base = devm_platform_ioremap_resource_byname(pdev, "nand-int-base");
        if (IS_ERR(priv->base))
                return PTR_ERR(priv->base);

        soc->ctlrdy_ack = bcmbca_nand_intc_ack;
        soc->ctlrdy_set_enabled = bcmbca_nand_intc_set;
        soc->read_data_bus = bcmbca_read_data_bus;

        return brcmnand_probe(pdev, soc);
}

static const struct of_device_id bcmbca_nand_of_match[] = {
        { .compatible = "brcm,nand-bcm63138" },
        {},
};
MODULE_DEVICE_TABLE(of, bcmbca_nand_of_match);

static struct platform_driver bcmbca_nand_driver = {
        .probe                  = bcmbca_nand_probe,
        .remove                 = brcmnand_remove,
        .driver = {
                .name           = "bcmbca_nand",
                .pm             = &brcmnand_pm_ops,
                .of_match_table = bcmbca_nand_of_match,
        }
};
module_platform_driver(bcmbca_nand_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Brian Norris");
MODULE_DESCRIPTION("NAND driver for BCMBCA");