mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 20:51:44 +00:00
b6b7ef932a
Apple SoCs contain eFuses used to store factory-programmed data such as calibration values for the PCIe or the Type-C PHY. They are organized as 32bit values exposed as MMIO. Signed-off-by: Sven Peter <sven@svenpeter.dev> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20220429162701.2222-6-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
81 lines
1.8 KiB
C
81 lines
1.8 KiB
C
// 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,
|
|
.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_LICENSE("GPL");
|