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U-Boot environment variables are stored in a specific format. Actual data can be placed in various storage sources (MTD, UBI volume, EEPROM, NVRAM, etc.). Move all generic (NVMEM device independent) code from NVMEM device driver to an NVMEM layout driver. Then add a simple NVMEM layout code on top of it. This allows using NVMEM layout for parsing U-Boot env data stored in any kind of NVMEM device. The old NVMEM glue driver stays in place for handling bindings in the MTD context. To avoid code duplication it uses exported layout parsing function. Please note that handling MTD & NVMEM layout bindings may be refactored in the future. Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20240902142952.71639-5-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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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