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

   1 From b152bbeb0282bfcf6f91d0d5befd7582c1c3fc23 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Fri, 5 Mar 2021 19:32:36 +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 ---
  14  drivers/nvmem/Kconfig      |  9 +++++
  15  drivers/nvmem/Makefile     |  2 +
  16  drivers/nvmem/brcm_nvram.c | 78 ++++++++++++++++++++++++++++++++++++++
  17  3 files changed, 89 insertions(+)
  18  create mode 100644 drivers/nvmem/brcm_nvram.c
  19
  20 --- a/drivers/nvmem/Kconfig
  21 +++ b/drivers/nvmem/Kconfig
  22 @@ -270,4 +270,13 @@ config SPRD_EFUSE
  23           This driver can also be built as a module. If so, the module
  24           will be called nvmem-sprd-efuse.
  25
  26 +
  27 +config NVMEM_BRCM_NVRAM
  28 +       tristate "Broadcom's NVRAM support"
  29 +       depends on ARCH_BCM_5301X || COMPILE_TEST
  30 +       depends on HAS_IOMEM
  31 +       help
  32 +         This driver provides support for Broadcom's NVRAM that can be accessed
  33 +         using I/O mapping.
  34 +
  35  endif
  36 --- a/drivers/nvmem/Makefile
  37 +++ b/drivers/nvmem/Makefile
  38 @@ -55,3 +55,5 @@ obj-$(CONFIG_NVMEM_ZYNQMP)    += nvmem_zynq
  39  nvmem_zynqmp_nvmem-y           := zynqmp_nvmem.o
  40  obj-$(CONFIG_SPRD_EFUSE)       += nvmem_sprd_efuse.o
  41  nvmem_sprd_efuse-y             := sprd-efuse.o
  42 +obj-$(CONFIG_NVMEM_BRCM_NVRAM) += nvmem_brcm_nvram.o
  43 +nvmem_brcm_nvram-y             := brcm_nvram.o
  44 --- /dev/null
  45 +++ b/drivers/nvmem/brcm_nvram.c
  46 @@ -0,0 +1,78 @@
  47 +// SPDX-License-Identifier: GPL-2.0-only
  48 +/*
  49 + * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>
  50 + */
  51 +
  52 +#include <linux/io.h>
  53 +#include <linux/mod_devicetable.h>
  54 +#include <linux/module.h>
  55 +#include <linux/nvmem-provider.h>
  56 +#include <linux/platform_device.h>
  57 +
  58 +struct brcm_nvram {
  59 +       struct device *dev;
  60 +       void __iomem *base;
  61 +};
  62 +
  63 +static int brcm_nvram_read(void *context, unsigned int offset, void *val,
  64 +                          size_t bytes)
  65 +{
  66 +       struct brcm_nvram *priv = context;
  67 +       u8 *dst = val;
  68 +
  69 +       while (bytes--)
  70 +               *dst++ = readb(priv->base + offset++);
  71 +
  72 +       return 0;
  73 +}
  74 +
  75 +static int brcm_nvram_probe(struct platform_device *pdev)
  76 +{
  77 +       struct nvmem_config config = {
  78 +               .name = "brcm-nvram",
  79 +               .reg_read = brcm_nvram_read,
  80 +       };
  81 +       struct device *dev = &pdev->dev;
  82 +       struct resource *res;
  83 +       struct brcm_nvram *priv;
  84 +
  85 +       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  86 +       if (!priv)
  87 +               return -ENOMEM;
  88 +       priv->dev = dev;
  89 +
  90 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  91 +       priv->base = devm_ioremap_resource(dev, res);
  92 +       if (IS_ERR(priv->base))
  93 +               return PTR_ERR(priv->base);
  94 +
  95 +       config.dev = dev;
  96 +       config.priv = priv;
  97 +       config.size = resource_size(res);
  98 +
  99 +       return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
 100 +}
 101 +
 102 +static const struct of_device_id brcm_nvram_of_match_table[] = {
 103 +       { .compatible = "brcm,nvram", },
 104 +       {},
 105 +};
 106 +
 107 +static struct platform_driver brcm_nvram_driver = {
 108 +       .probe = brcm_nvram_probe,
 109 +       .driver = {
 110 +               .name = "brcm_nvram",
 111 +               .of_match_table = brcm_nvram_of_match_table,
 112 +       },
 113 +};
 114 +
 115 +static int __init brcm_nvram_init(void)
 116 +{
 117 +       return platform_driver_register(&brcm_nvram_driver);
 118 +}
 119 +
 120 +subsys_initcall_sync(brcm_nvram_init);
 121 +
 122 +MODULE_AUTHOR("Rafał Miłecki");
 123 +MODULE_LICENSE("GPL");
 124 +MODULE_DEVICE_TABLE(of, brcm_nvram_of_match_table);