// SPDX-License-Identifier: GPL-2.0
/*
 * Linux driver for RPC-IF HyperFlash
 *
 * Copyright (C) 2019-2020 Cogent Embedded, Inc.
 */

#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mtd/hyperbus.h>
#include <linux/mtd/mtd.h>
#include <linux/mux/consumer.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/types.h>

#include <memory/renesas-rpc-if.h>

struct  rpcif_hyperbus {
        struct rpcif rpc;
        struct hyperbus_ctlr ctlr;
        struct hyperbus_device hbdev;
};

static const struct rpcif_op rpcif_op_tmpl = {
        .cmd = {
                .buswidth = 8,
                .ddr = true,
        },
        .ocmd = {
                .buswidth = 8,
                .ddr = true,
        },
        .addr = {
                .nbytes = 1,
                .buswidth = 8,
                .ddr = true,
        },
        .data = {
                .buswidth = 8,
                .ddr = true,
        },
};

static void rpcif_hb_prepare_read(struct rpcif *rpc, void *to,
                                  unsigned long from, ssize_t len)
{
        struct rpcif_op op = rpcif_op_tmpl;

        op.cmd.opcode = HYPERBUS_RW_READ | HYPERBUS_AS_MEM;
        op.addr.val = from >> 1;
        op.dummy.buswidth = 1;
        op.dummy.ncycles = 15;
        op.data.dir = RPCIF_DATA_IN;
        op.data.nbytes = len;
        op.data.buf.in = to;

        rpcif_prepare(rpc->dev, &op, NULL, NULL);
}

static void rpcif_hb_prepare_write(struct rpcif *rpc, unsigned long to,
                                   void *from, ssize_t len)
{
        struct rpcif_op op = rpcif_op_tmpl;

        op.cmd.opcode = HYPERBUS_RW_WRITE | HYPERBUS_AS_MEM;
        op.addr.val = to >> 1;
        op.data.dir = RPCIF_DATA_OUT;
        op.data.nbytes = len;
        op.data.buf.out = from;

        rpcif_prepare(rpc->dev, &op, NULL, NULL);
}

static u16 rpcif_hb_read16(struct hyperbus_device *hbdev, unsigned long addr)
{
        struct rpcif_hyperbus *hyperbus =
                container_of(hbdev, struct rpcif_hyperbus, hbdev);
        map_word data;

        rpcif_hb_prepare_read(&hyperbus->rpc, &data, addr, 2);

        rpcif_manual_xfer(hyperbus->rpc.dev);

        return data.x[0];
}

static void rpcif_hb_write16(struct hyperbus_device *hbdev, unsigned long addr,
                             u16 data)
{
        struct rpcif_hyperbus *hyperbus =
                container_of(hbdev, struct rpcif_hyperbus, hbdev);

        rpcif_hb_prepare_write(&hyperbus->rpc, addr, &data, 2);

        rpcif_manual_xfer(hyperbus->rpc.dev);
}

static void rpcif_hb_copy_from(struct hyperbus_device *hbdev, void *to,
                               unsigned long from, ssize_t len)
{
        struct rpcif_hyperbus *hyperbus =
                container_of(hbdev, struct rpcif_hyperbus, hbdev);

        rpcif_hb_prepare_read(&hyperbus->rpc, to, from, len);

        rpcif_dirmap_read(hyperbus->rpc.dev, from, len, to);
}

static const struct hyperbus_ops rpcif_hb_ops = {
        .read16 = rpcif_hb_read16,
        .write16 = rpcif_hb_write16,
        .copy_from = rpcif_hb_copy_from,
};

static int rpcif_hb_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct rpcif_hyperbus *hyperbus;
        int error;

        hyperbus = devm_kzalloc(dev, sizeof(*hyperbus), GFP_KERNEL);
        if (!hyperbus)
                return -ENOMEM;

        error = rpcif_sw_init(&hyperbus->rpc, pdev->dev.parent);
        if (error)
                return error;

        platform_set_drvdata(pdev, hyperbus);

        pm_runtime_enable(hyperbus->rpc.dev);

        error = rpcif_hw_init(hyperbus->rpc.dev, true);
        if (error)
                goto out_disable_rpm;

        hyperbus->hbdev.map.size = hyperbus->rpc.size;
        hyperbus->hbdev.map.virt = hyperbus->rpc.dirmap;

        hyperbus->ctlr.dev = dev;
        hyperbus->ctlr.ops = &rpcif_hb_ops;
        hyperbus->hbdev.ctlr = &hyperbus->ctlr;
        hyperbus->hbdev.np = of_get_next_child(pdev->dev.parent->of_node, NULL);
        error = hyperbus_register_device(&hyperbus->hbdev);
        if (error)
                goto out_disable_rpm;

        return 0;

out_disable_rpm:
        pm_runtime_disable(hyperbus->rpc.dev);
        return error;
}

static void rpcif_hb_remove(struct platform_device *pdev)
{
        struct rpcif_hyperbus *hyperbus = platform_get_drvdata(pdev);

        hyperbus_unregister_device(&hyperbus->hbdev);

        pm_runtime_disable(hyperbus->rpc.dev);
}

static const struct platform_device_id rpc_if_hyperflash_id_table[] = {
        { .name = "rpc-if-hyperflash" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, rpc_if_hyperflash_id_table);

static struct platform_driver rpcif_platform_driver = {
        .probe  = rpcif_hb_probe,
        .remove = rpcif_hb_remove,
        .id_table = rpc_if_hyperflash_id_table,
        .driver = {
                .name   = "rpc-if-hyperflash",
        },
};

module_platform_driver(rpcif_platform_driver);

MODULE_DESCRIPTION("Renesas RPC-IF HyperFlash driver");
MODULE_LICENSE("GPL v2");