// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Amlogic Meson GX eFuse Driver
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*
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* Copyright (c) 2016 Endless Computers, Inc.
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* Author: Carlo Caione <carlo@endlessm.com>
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*/
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#include <linux/clk.h>
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#include <linux/module.h>
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#include <linux/nvmem-provider.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/firmware/meson/meson_sm.h>
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static int meson_efuse_read(void *context, unsigned int offset,
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void *val, size_t bytes)
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{
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struct meson_sm_firmware *fw = context;
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return meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,
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bytes, 0, 0, 0);
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}
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static int meson_efuse_write(void *context, unsigned int offset,
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void *val, size_t bytes)
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{
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struct meson_sm_firmware *fw = context;
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return meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,
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bytes, 0, 0, 0);
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}
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static const struct of_device_id meson_efuse_match[] = {
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{ .compatible = "amlogic,meson-gxbb-efuse", },
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(of, meson_efuse_match);
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static int meson_efuse_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct meson_sm_firmware *fw;
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struct device_node *sm_np;
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struct nvmem_device *nvmem;
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struct nvmem_config *econfig;
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struct clk *clk;
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unsigned int size;
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int ret;
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sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);
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if (!sm_np) {
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dev_err(&pdev->dev, "no secure-monitor node\n");
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return -ENODEV;
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}
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fw = meson_sm_get(sm_np);
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of_node_put(sm_np);
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if (!fw)
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return -EPROBE_DEFER;
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clk = devm_clk_get(dev, NULL);
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if (IS_ERR(clk)) {
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ret = PTR_ERR(clk);
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if (ret != -EPROBE_DEFER)
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dev_err(dev, "failed to get efuse gate");
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return ret;
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}
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ret = clk_prepare_enable(clk);
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if (ret) {
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dev_err(dev, "failed to enable gate");
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return ret;
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}
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ret = devm_add_action_or_reset(dev,
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(void(*)(void *))clk_disable_unprepare,
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clk);
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if (ret) {
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dev_err(dev, "failed to add disable callback");
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return ret;
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}
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if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
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dev_err(dev, "failed to get max user");
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return -EINVAL;
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}
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econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
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if (!econfig)
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return -ENOMEM;
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econfig->dev = dev;
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econfig->name = dev_name(dev);
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econfig->stride = 1;
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econfig->word_size = 1;
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econfig->reg_read = meson_efuse_read;
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econfig->reg_write = meson_efuse_write;
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econfig->size = size;
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econfig->priv = fw;
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nvmem = devm_nvmem_register(&pdev->dev, econfig);
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return PTR_ERR_OR_ZERO(nvmem);
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}
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static struct platform_driver meson_efuse_driver = {
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.probe = meson_efuse_probe,
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.driver = {
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.name = "meson-efuse",
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.of_match_table = meson_efuse_match,
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},
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};
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module_platform_driver(meson_efuse_driver);
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MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
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MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
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MODULE_LICENSE("GPL v2");
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