Commit f7845101 authored by Michael Walle's avatar Michael Walle Committed by Greg Kroah-Hartman
Browse files

nvmem: add driver for Layerscape SFP (Security Fuse Processor) 



Add support for the Security Fuse Processor found on Layerscape SoCs.
This driver implements basic read access.

Signed-off-by: default avatarMichael Walle <michael@walle.cc>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220220151527.17216-10-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6f9817cd

drivers/nvmem/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -300,4 +300,16 @@ config NVMEM_BRCM_NVRAM 
	  This driver provides support for Broadcom's NVRAM that can be accessed

	  using I/O mapping.



config NVMEM_LAYERSCAPE_SFP

	tristate "Layerscape SFP (Security Fuse Processor) support"

	depends on ARCH_LAYERSCAPE || COMPILE_TEST

	depends on HAS_IOMEM

	help

	  This driver provides support to read the eFuses on Freescale

	  Layerscape SoC's. For example, the vendor provides a per part

	  unique ID there.



	  This driver can also be built as a module. If so, the module

	  will be called layerscape-sfp.



endif

drivers/nvmem/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -61,3 +61,5 @@ obj-$(CONFIG_NVMEM_RMEM) += nvmem-rmem.o 
nvmem-rmem-y			:= rmem.o

obj-$(CONFIG_NVMEM_BRCM_NVRAM)	+= nvmem_brcm_nvram.o

nvmem_brcm_nvram-y		:= brcm_nvram.o

obj-$(CONFIG_NVMEM_LAYERSCAPE_SFP)	+= nvmem-layerscape-sfp.o

nvmem-layerscape-sfp-y		:= layerscape-sfp.o

drivers/nvmem/layerscape-sfp.c

0 → 100644
+89 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Layerscape SFP driver

 *

 * Copyright (c) 2022 Michael Walle <michael@walle.cc>

 *

 */



#include <linux/device.h>

#include <linux/io.h>

#include <linux/mod_devicetable.h>

#include <linux/module.h>

#include <linux/nvmem-provider.h>

#include <linux/platform_device.h>

#include <linux/property.h>



#define LAYERSCAPE_SFP_OTP_OFFSET	0x0200



struct layerscape_sfp_priv {

	void __iomem *base;

};



struct layerscape_sfp_data {

	int size;

};



static int layerscape_sfp_read(void *context, unsigned int offset, void *val,

			       size_t bytes)

{

	struct layerscape_sfp_priv *priv = context;



	memcpy_fromio(val, priv->base + LAYERSCAPE_SFP_OTP_OFFSET + offset,

		      bytes);



	return 0;

}



static struct nvmem_config layerscape_sfp_nvmem_config = {

	.name = "fsl-sfp",

	.reg_read = layerscape_sfp_read,

};



static int layerscape_sfp_probe(struct platform_device *pdev)

{

	const struct layerscape_sfp_data *data;

	struct layerscape_sfp_priv *priv;

	struct nvmem_device *nvmem;



	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);

	if (!priv)

		return -ENOMEM;



	priv->base = devm_platform_ioremap_resource(pdev, 0);

	if (IS_ERR(priv->base))

		return PTR_ERR(priv->base);



	data = device_get_match_data(&pdev->dev);



	layerscape_sfp_nvmem_config.size = data->size;

	layerscape_sfp_nvmem_config.dev = &pdev->dev;

	layerscape_sfp_nvmem_config.priv = priv;



	nvmem = devm_nvmem_register(&pdev->dev, &layerscape_sfp_nvmem_config);



	return PTR_ERR_OR_ZERO(nvmem);

}



static const struct layerscape_sfp_data ls1028a_data = {

	.size = 0x88,

};



static const struct of_device_id layerscape_sfp_dt_ids[] = {

	{ .compatible = "fsl,ls1028a-sfp", .data = &ls1028a_data },

	{},

};

MODULE_DEVICE_TABLE(of, layerscape_sfp_dt_ids);



static struct platform_driver layerscape_sfp_driver = {

	.probe	= layerscape_sfp_probe,

	.driver = {

		.name	= "layerscape_sfp",

		.of_match_table = layerscape_sfp_dt_ids,

	},

};

module_platform_driver(layerscape_sfp_driver);



MODULE_AUTHOR("Michael Walle <michael@walle.cc>");

MODULE_DESCRIPTION("Layerscape Security Fuse Processor driver");

MODULE_LICENSE("GPL");