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// SPDX-License-Identifier: GPL-2.0-only
/*
* Apple SoC eFuse driver
*
* Copyright (C) The Asahi Linux Contributors
*/
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>
struct apple_efuses_priv {
void __iomem *fuses;
};
static int apple_efuses_read(void *context, unsigned int offset, void *val,
size_t bytes)
{
struct apple_efuses_priv *priv = context;
u32 *dst = val;
while (bytes >= sizeof(u32)) {
*dst++ = readl_relaxed(priv->fuses + offset);
bytes -= sizeof(u32);
offset += sizeof(u32);
}
return 0;
}
static int apple_efuses_probe(struct platform_device *pdev)
{
struct apple_efuses_priv *priv;
struct resource *res;
struct nvmem_config config = {
.dev = &pdev->dev,
.add_legacy_fixed_of_cells = true,
.read_only = true,
.reg_read = apple_efuses_read,
.stride = sizeof(u32),
.word_size = sizeof(u32),
.name = "apple_efuses_nvmem",
.id = NVMEM_DEVID_AUTO,
.root_only = true,
};
priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->fuses = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(priv->fuses))
return PTR_ERR(priv->fuses);
config.priv = priv;
config.size = resource_size(res);
return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
}
static const struct of_device_id apple_efuses_of_match[] = {
{ .compatible = "apple,efuses", },
{}
};
MODULE_DEVICE_TABLE(of, apple_efuses_of_match);
static struct platform_driver apple_efuses_driver = {
.driver = {
.name = "apple_efuses",
.of_match_table = apple_efuses_of_match,
},
.probe = apple_efuses_probe,
};
module_platform_driver(apple_efuses_driver);
MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
MODULE_DESCRIPTION("Apple SoC eFuse driver");
MODULE_LICENSE("GPL");
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