101 lines
2.5 KiB
C
101 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2022 Rafał Miłecki <rafal@milecki.pl>
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*/
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/mtd/mtd.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/slab.h>
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#include "layouts/u-boot-env.h"
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struct u_boot_env {
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struct device *dev;
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struct nvmem_device *nvmem;
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enum u_boot_env_format format;
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struct mtd_info *mtd;
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};
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static int u_boot_env_read(void *context, unsigned int offset, void *val,
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size_t bytes)
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{
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struct u_boot_env *priv = context;
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struct device *dev = priv->dev;
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size_t bytes_read;
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int err;
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err = mtd_read(priv->mtd, offset, bytes, &bytes_read, val);
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if (err && !mtd_is_bitflip(err)) {
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dev_err(dev, "Failed to read from mtd: %d\n", err);
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return err;
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}
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if (bytes_read != bytes) {
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dev_err(dev, "Failed to read %zu bytes\n", bytes);
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return -EIO;
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}
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return 0;
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}
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static int u_boot_env_probe(struct platform_device *pdev)
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{
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struct nvmem_config config = {
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.name = "u-boot-env",
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.reg_read = u_boot_env_read,
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};
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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struct u_boot_env *priv;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->dev = dev;
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priv->format = (uintptr_t)of_device_get_match_data(dev);
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priv->mtd = of_get_mtd_device_by_node(np);
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if (IS_ERR(priv->mtd)) {
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dev_err_probe(dev, PTR_ERR(priv->mtd), "Failed to get %pOF MTD\n", np);
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return PTR_ERR(priv->mtd);
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}
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config.dev = dev;
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config.priv = priv;
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config.size = priv->mtd->size;
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priv->nvmem = devm_nvmem_register(dev, &config);
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if (IS_ERR(priv->nvmem))
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return PTR_ERR(priv->nvmem);
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return u_boot_env_parse(dev, priv->nvmem, priv->format);
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}
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static const struct of_device_id u_boot_env_of_match_table[] = {
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{ .compatible = "u-boot,env", .data = (void *)U_BOOT_FORMAT_SINGLE, },
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{ .compatible = "u-boot,env-redundant-bool", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
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{ .compatible = "u-boot,env-redundant-count", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
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{ .compatible = "brcm,env", .data = (void *)U_BOOT_FORMAT_BROADCOM, },
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{},
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};
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static struct platform_driver u_boot_env_driver = {
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.probe = u_boot_env_probe,
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.driver = {
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.name = "u_boot_env",
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.of_match_table = u_boot_env_of_match_table,
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},
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};
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module_platform_driver(u_boot_env_driver);
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MODULE_AUTHOR("Rafał Miłecki");
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MODULE_DESCRIPTION("U-Boot environment variables support module");
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MODULE_LICENSE("GPL");
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MODULE_DEVICE_TABLE(of, u_boot_env_of_match_table);
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