linux/drivers/nvmem/meson-efuse.c
Rafał Miłecki 26e2fe4cab nvmem: add explicit config option to read old syntax fixed OF cells
[ Upstream commit 2cc3b37f5b6df8189d55d0e812d9658ce256dfec ]

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 It has been replaced by the "fixed-layout" NVMEM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>
Stable-dep-of: d2d73a6dd173 ("mtd: limit OTP NVMEM cell parse to non-NAND devices")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:01:55 +02:00

103 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Amlogic Meson GX eFuse Driver
*
* Copyright (c) 2016 Endless Computers, Inc.
* Author: Carlo Caione <carlo@endlessm.com>
*/
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/firmware/meson/meson_sm.h>
static int meson_efuse_read(void *context, unsigned int offset,
void *val, size_t bytes)
{
struct meson_sm_firmware *fw = context;
return meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,
bytes, 0, 0, 0);
}
static int meson_efuse_write(void *context, unsigned int offset,
void *val, size_t bytes)
{
struct meson_sm_firmware *fw = context;
return meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,
bytes, 0, 0, 0);
}
static const struct of_device_id meson_efuse_match[] = {
{ .compatible = "amlogic,meson-gxbb-efuse", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, meson_efuse_match);
static int meson_efuse_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct meson_sm_firmware *fw;
struct device_node *sm_np;
struct nvmem_device *nvmem;
struct nvmem_config *econfig;
struct clk *clk;
unsigned int size;
sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);
if (!sm_np) {
dev_err(&pdev->dev, "no secure-monitor node\n");
return -ENODEV;
}
fw = meson_sm_get(sm_np);
of_node_put(sm_np);
if (!fw)
return -EPROBE_DEFER;
clk = devm_clk_get_enabled(dev, NULL);
if (IS_ERR(clk))
return dev_err_probe(dev, PTR_ERR(clk), "failed to get efuse gate");
if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
dev_err(dev, "failed to get max user");
return -EINVAL;
}
econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
if (!econfig)
return -ENOMEM;
econfig->dev = dev;
econfig->name = dev_name(dev);
econfig->add_legacy_fixed_of_cells = true;
econfig->stride = 1;
econfig->word_size = 1;
econfig->reg_read = meson_efuse_read;
econfig->reg_write = meson_efuse_write;
econfig->size = size;
econfig->priv = fw;
nvmem = devm_nvmem_register(&pdev->dev, econfig);
return PTR_ERR_OR_ZERO(nvmem);
}
static struct platform_driver meson_efuse_driver = {
.probe = meson_efuse_probe,
.driver = {
.name = "meson-efuse",
.of_match_table = meson_efuse_match,
},
};
module_platform_driver(meson_efuse_driver);
MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
MODULE_LICENSE("GPL v2");