// SPDX-License-Identifier: GPL-2.0-only
/*
 * Amlogic Meson GX eFuse Driver
 *
 * Copyright (c) 2016 Endless Computers, Inc.
 * Author: Carlo Caione <carlo@endlessm.com>
 */

#include <linux/clk.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/platform_device.h>

#include <linux/firmware/meson/meson_sm.h>

static int meson_efuse_read(void *context, unsigned int offset,
                            void *val, size_t bytes)
{
        struct meson_sm_firmware *fw = context;
        int ret;

        ret = meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,
                                 bytes, 0, 0, 0);

        return ret < 0 ? ret : 0;
}

static int meson_efuse_write(void *context, unsigned int offset,
                             void *val, size_t bytes)
{
        struct meson_sm_firmware *fw = context;
        int ret;

        ret = meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,
                                  bytes, 0, 0, 0);

        return ret < 0 ? ret : 0;
}

static const struct of_device_id meson_efuse_match[] = {
        { .compatible = "amlogic,meson-gxbb-efuse", },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, meson_efuse_match);

static int meson_efuse_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct meson_sm_firmware *fw;
        struct nvmem_device *nvmem;
        struct nvmem_config *econfig;
        struct clk *clk;
        unsigned int size;
        struct device_node *sm_np __free(device_node) =
                        of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);

        if (!sm_np) {
                dev_err(&pdev->dev, "no secure-monitor node\n");
                return -ENODEV;
        }

        fw = meson_sm_get(sm_np);
        if (!fw)
                return -EPROBE_DEFER;

        clk = devm_clk_get_enabled(dev, NULL);
        if (IS_ERR(clk))
                return dev_err_probe(dev, PTR_ERR(clk), "failed to get efuse gate");

        if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
                dev_err(dev, "failed to get max user");
                return -EINVAL;
        }

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

        econfig->dev = dev;
        econfig->name = dev_name(dev);
        econfig->add_legacy_fixed_of_cells = true;
        econfig->stride = 1;
        econfig->word_size = 1;
        econfig->reg_read = meson_efuse_read;
        econfig->reg_write = meson_efuse_write;
        econfig->size = size;
        econfig->priv = fw;

        nvmem = devm_nvmem_register(&pdev->dev, econfig);

        return PTR_ERR_OR_ZERO(nvmem);
}

static struct platform_driver meson_efuse_driver = {
        .probe = meson_efuse_probe,
        .driver = {
                .name = "meson-efuse",
                .of_match_table = meson_efuse_match,
        },
};

module_platform_driver(meson_efuse_driver);

MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
MODULE_LICENSE("GPL v2");