target/linux/generic/backport-5.15/804-v5.18-0007-nvmem-add-driver-for-Layerscape-SFP-Security-Fuse-Pr.patch

   1 From f78451012b9e159afdba31c3eb69f223a9f42adc Mon Sep 17 00:00:00 2001
   2 From: Michael Walle <michael@walle.cc>
   3 Date: Sun, 20 Feb 2022 15:15:23 +0000
   4 Subject: [PATCH] nvmem: add driver for Layerscape SFP (Security Fuse
   5  Processor)
   6
   7 Add support for the Security Fuse Processor found on Layerscape SoCs.
   8 This driver implements basic read access.
   9
  10 Signed-off-by: Michael Walle <michael@walle.cc>
  11 Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
  12 Link: https://lore.kernel.org/r/20220220151527.17216-10-srinivas.kandagatla@linaro.org
  13 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  14 ---
  15  drivers/nvmem/Kconfig          | 12 +++++
  16  drivers/nvmem/Makefile         |  2 +
  17  drivers/nvmem/layerscape-sfp.c | 89 ++++++++++++++++++++++++++++++++++
  18  3 files changed, 103 insertions(+)
  19  create mode 100644 drivers/nvmem/layerscape-sfp.c
  20
  21 --- a/drivers/nvmem/Kconfig
  22 +++ b/drivers/nvmem/Kconfig
  23 @@ -300,4 +300,16 @@ config NVMEM_BRCM_NVRAM
  24           This driver provides support for Broadcom's NVRAM that can be accessed
  25           using I/O mapping.
  26
  27 +config NVMEM_LAYERSCAPE_SFP
  28 +       tristate "Layerscape SFP (Security Fuse Processor) support"
  29 +       depends on ARCH_LAYERSCAPE || COMPILE_TEST
  30 +       depends on HAS_IOMEM
  31 +       help
  32 +         This driver provides support to read the eFuses on Freescale
  33 +         Layerscape SoC's. For example, the vendor provides a per part
  34 +         unique ID there.
  35 +
  36 +         This driver can also be built as a module. If so, the module
  37 +         will be called layerscape-sfp.
  38 +
  39  endif
  40 --- a/drivers/nvmem/Makefile
  41 +++ b/drivers/nvmem/Makefile
  42 @@ -61,3 +61,5 @@ obj-$(CONFIG_NVMEM_RMEM)      += nvmem-rmem.
  43  nvmem-rmem-y                   := rmem.o
  44  obj-$(CONFIG_NVMEM_BRCM_NVRAM) += nvmem_brcm_nvram.o
  45  nvmem_brcm_nvram-y             := brcm_nvram.o
  46 +obj-$(CONFIG_NVMEM_LAYERSCAPE_SFP)     += nvmem-layerscape-sfp.o
  47 +nvmem-layerscape-sfp-y         := layerscape-sfp.o
  48 --- /dev/null
  49 +++ b/drivers/nvmem/layerscape-sfp.c
  50 @@ -0,0 +1,89 @@
  51 +// SPDX-License-Identifier: GPL-2.0-only
  52 +/*
  53 + * Layerscape SFP driver
  54 + *
  55 + * Copyright (c) 2022 Michael Walle <michael@walle.cc>
  56 + *
  57 + */
  58 +
  59 +#include <linux/device.h>
  60 +#include <linux/io.h>
  61 +#include <linux/mod_devicetable.h>
  62 +#include <linux/module.h>
  63 +#include <linux/nvmem-provider.h>
  64 +#include <linux/platform_device.h>
  65 +#include <linux/property.h>
  66 +
  67 +#define LAYERSCAPE_SFP_OTP_OFFSET      0x0200
  68 +
  69 +struct layerscape_sfp_priv {
  70 +       void __iomem *base;
  71 +};
  72 +
  73 +struct layerscape_sfp_data {
  74 +       int size;
  75 +};
  76 +
  77 +static int layerscape_sfp_read(void *context, unsigned int offset, void *val,
  78 +                              size_t bytes)
  79 +{
  80 +       struct layerscape_sfp_priv *priv = context;
  81 +
  82 +       memcpy_fromio(val, priv->base + LAYERSCAPE_SFP_OTP_OFFSET + offset,
  83 +                     bytes);
  84 +
  85 +       return 0;
  86 +}
  87 +
  88 +static struct nvmem_config layerscape_sfp_nvmem_config = {
  89 +       .name = "fsl-sfp",
  90 +       .reg_read = layerscape_sfp_read,
  91 +};
  92 +
  93 +static int layerscape_sfp_probe(struct platform_device *pdev)
  94 +{
  95 +       const struct layerscape_sfp_data *data;
  96 +       struct layerscape_sfp_priv *priv;
  97 +       struct nvmem_device *nvmem;
  98 +
  99 +       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 100 +       if (!priv)
 101 +               return -ENOMEM;
 102 +
 103 +       priv->base = devm_platform_ioremap_resource(pdev, 0);
 104 +       if (IS_ERR(priv->base))
 105 +               return PTR_ERR(priv->base);
 106 +
 107 +       data = device_get_match_data(&pdev->dev);
 108 +
 109 +       layerscape_sfp_nvmem_config.size = data->size;
 110 +       layerscape_sfp_nvmem_config.dev = &pdev->dev;
 111 +       layerscape_sfp_nvmem_config.priv = priv;
 112 +
 113 +       nvmem = devm_nvmem_register(&pdev->dev, &layerscape_sfp_nvmem_config);
 114 +
 115 +       return PTR_ERR_OR_ZERO(nvmem);
 116 +}
 117 +
 118 +static const struct layerscape_sfp_data ls1028a_data = {
 119 +       .size = 0x88,
 120 +};
 121 +
 122 +static const struct of_device_id layerscape_sfp_dt_ids[] = {
 123 +       { .compatible = "fsl,ls1028a-sfp", .data = &ls1028a_data },
 124 +       {},
 125 +};
 126 +MODULE_DEVICE_TABLE(of, layerscape_sfp_dt_ids);
 127 +
 128 +static struct platform_driver layerscape_sfp_driver = {
 129 +       .probe  = layerscape_sfp_probe,
 130 +       .driver = {
 131 +               .name   = "layerscape_sfp",
 132 +               .of_match_table = layerscape_sfp_dt_ids,
 133 +       },
 134 +};
 135 +module_platform_driver(layerscape_sfp_driver);
 136 +
 137 +MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
 138 +MODULE_DESCRIPTION("Layerscape Security Fuse Processor driver");
 139 +MODULE_LICENSE("GPL");