linux/drivers/nvmem/apple-efuses.c
Rafał Miłecki 2cc3b37f5b nvmem: add explicit config option to read old syntax fixed OF cells
Binding for fixed NVMEM cells defined directly as NVMEM device subnodes
has been deprecated. It has been replaced by the "fixed-layout" NVMEM
layout binding.

New syntax is meant to be clearer and should help avoiding imprecise
bindings.

NVMEM subsystem already supports the new binding. It should be a good
idea to limit support for old syntax to existing drivers that actually
support & use it (we can't break backward compatibility!). That way we
additionally encourage new bindings & drivers to ignore deprecated
binding.

It wasn't clear (to me) if rtc and w1 code actually uses old syntax
fixed cells. I enabled them to don't risk any breakage.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
[for meson-{efuse,mx-efuse}.c]
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
[for mtk-efuse.c, nvmem/core.c, nvmem-provider.h]
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[MT8192, MT8195 Chromebooks]
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[for microchip-otpc.c]
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
[SAMA7G5-EK]
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20231020105545.216052-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-21 19:19:06 +02:00

82 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,
.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_LICENSE("GPL");