git.openwrt.org Git - openwrt/staging/xback.git/blob

   1 From 3fef9ed0627af30753a2404b8bd59d92cdb4c0ce Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Tue, 30 Mar 2021 12:12:36 +0100
   4 Subject: [PATCH] nvmem: brcm_nvram: new driver exposing Broadcom's NVRAM
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 This driver provides access to Broadcom's NVRAM.
  10
  11 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  12 Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
  13 Link: https://lore.kernel.org/r/20210330111241.19401-6-srinivas.kandagatla@linaro.org
  14 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  15 ---
  16  drivers/nvmem/Kconfig      |  9 +++++
  17  drivers/nvmem/Makefile     |  2 +
  18  drivers/nvmem/brcm_nvram.c | 78 ++++++++++++++++++++++++++++++++++++++
  19  3 files changed, 89 insertions(+)
  20  create mode 100644 drivers/nvmem/brcm_nvram.c
  21
  22 --- a/drivers/nvmem/Kconfig
  23 +++ b/drivers/nvmem/Kconfig
  24 @@ -278,4 +278,13 @@ config NVMEM_RMEM
  25
  26           This driver can also be built as a module. If so, the module
  27           will be called nvmem-rmem.
  28 +
  29 +config NVMEM_BRCM_NVRAM
  30 +       tristate "Broadcom's NVRAM support"
  31 +       depends on ARCH_BCM_5301X || COMPILE_TEST
  32 +       depends on HAS_IOMEM
  33 +       help
  34 +         This driver provides support for Broadcom's NVRAM that can be accessed
  35 +         using I/O mapping.
  36 +
  37  endif
  38 --- a/drivers/nvmem/Makefile
  39 +++ b/drivers/nvmem/Makefile
  40 @@ -57,3 +57,5 @@ obj-$(CONFIG_SPRD_EFUSE)      += nvmem_sprd_e
  41  nvmem_sprd_efuse-y             := sprd-efuse.o
  42  obj-$(CONFIG_NVMEM_RMEM)       += nvmem-rmem.o
  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 --- /dev/null
  47 +++ b/drivers/nvmem/brcm_nvram.c
  48 @@ -0,0 +1,78 @@
  49 +// SPDX-License-Identifier: GPL-2.0-only
  50 +/*
  51 + * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
  52 + */
  53 +
  54 +#include <linux/io.h>
  55 +#include <linux/mod_devicetable.h>
  56 +#include <linux/module.h>
  57 +#include <linux/nvmem-provider.h>
  58 +#include <linux/platform_device.h>
  59 +
  60 +struct brcm_nvram {
  61 +       struct device *dev;
  62 +       void __iomem *base;
  63 +};
  64 +
  65 +static int brcm_nvram_read(void *context, unsigned int offset, void *val,
  66 +                          size_t bytes)
  67 +{
  68 +       struct brcm_nvram *priv = context;
  69 +       u8 *dst = val;
  70 +
  71 +       while (bytes--)
  72 +               *dst++ = readb(priv->base + offset++);
  73 +
  74 +       return 0;
  75 +}
  76 +
  77 +static int brcm_nvram_probe(struct platform_device *pdev)
  78 +{
  79 +       struct nvmem_config config = {
  80 +               .name = "brcm-nvram",
  81 +               .reg_read = brcm_nvram_read,
  82 +       };
  83 +       struct device *dev = &pdev->dev;
  84 +       struct resource *res;
  85 +       struct brcm_nvram *priv;
  86 +
  87 +       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  88 +       if (!priv)
  89 +               return -ENOMEM;
  90 +       priv->dev = dev;
  91 +
  92 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  93 +       priv->base = devm_ioremap_resource(dev, res);
  94 +       if (IS_ERR(priv->base))
  95 +               return PTR_ERR(priv->base);
  96 +
  97 +       config.dev = dev;
  98 +       config.priv = priv;
  99 +       config.size = resource_size(res);
 100 +
 101 +       return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
 102 +}
 103 +
 104 +static const struct of_device_id brcm_nvram_of_match_table[] = {
 105 +       { .compatible = "brcm,nvram", },
 106 +       {},
 107 +};
 108 +
 109 +static struct platform_driver brcm_nvram_driver = {
 110 +       .probe = brcm_nvram_probe,
 111 +       .driver = {
 112 +               .name = "brcm_nvram",
 113 +               .of_match_table = brcm_nvram_of_match_table,
 114 +       },
 115 +};
 116 +
 117 +static int __init brcm_nvram_init(void)
 118 +{
 119 +       return platform_driver_register(&brcm_nvram_driver);
 120 +}
 121 +
 122 +subsys_initcall_sync(brcm_nvram_init);
 123 +
 124 +MODULE_AUTHOR("Rafał Miłecki");
 125 +MODULE_LICENSE("GPL");
 126 +MODULE_DEVICE_TABLE(of, brcm_nvram_of_match_table);