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linux/drivers/nvmem/sec-qfprom.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 It has been replaced by the "fixed-layout" NVMEM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

98 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
*/
#include <linux/firmware/qcom/qcom_scm.h>
#include <linux/mod_devicetable.h>
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
/**
* struct sec_qfprom - structure holding secure qfprom attributes
*
* @base: starting physical address for secure qfprom corrected address space.
* @dev: qfprom device structure.
*/
struct sec_qfprom {
phys_addr_t base;
struct device *dev;
};
static int sec_qfprom_reg_read(void *context, unsigned int reg, void *_val, size_t bytes)
{
struct sec_qfprom *priv = context;
unsigned int i;
u8 *val = _val;
u32 read_val;
u8 *tmp;
for (i = 0; i < bytes; i++, reg++) {
if (i == 0 || reg % 4 == 0) {
if (qcom_scm_io_readl(priv->base + (reg & ~3), &read_val)) {
dev_err(priv->dev, "Couldn't access fuse register\n");
return -EINVAL;
}
tmp = (u8 *)&read_val;
}
val[i] = tmp[reg & 3];
}
return 0;
}
static int sec_qfprom_probe(struct platform_device *pdev)
{
struct nvmem_config econfig = {
.name = "sec-qfprom",
.add_legacy_fixed_of_cells = true,
.stride = 1,
.word_size = 1,
.id = NVMEM_DEVID_AUTO,
.reg_read = sec_qfprom_reg_read,
};
struct device *dev = &pdev->dev;
struct nvmem_device *nvmem;
struct sec_qfprom *priv;
struct resource *res;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -EINVAL;
priv->base = res->start;
econfig.size = resource_size(res);
econfig.dev = dev;
econfig.priv = priv;
priv->dev = dev;
nvmem = devm_nvmem_register(dev, &econfig);
return PTR_ERR_OR_ZERO(nvmem);
}
static const struct of_device_id sec_qfprom_of_match[] = {
{ .compatible = "qcom,sec-qfprom" },
{/* sentinel */},
};
MODULE_DEVICE_TABLE(of, sec_qfprom_of_match);
static struct platform_driver qfprom_driver = {
.probe = sec_qfprom_probe,
.driver = {
.name = "qcom_sec_qfprom",
.of_match_table = sec_qfprom_of_match,
},
};
module_platform_driver(qfprom_driver);
MODULE_DESCRIPTION("Qualcomm Secure QFPROM driver");
MODULE_LICENSE("GPL");