target/linux/generic/backport-5.15/804-v5.18-0010-nvmem-brcm_nvram-parse-NVRAM-content-into-NVMEM-cell.patch

   1 From 6e977eaa8280e957b87904b536661550f2a6b3e8 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Fri, 25 Feb 2022 17:58:20 +0000
   4 Subject: [PATCH] nvmem: brcm_nvram: parse NVRAM content into NVMEM cells
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 NVRAM consist of header and NUL separated key-value pairs. Parse it and
  10 create NVMEM cell for every key-value entry.
  11
  12 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  13 Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
  14 Link: https://lore.kernel.org/r/20220225175822.8293-3-srinivas.kandagatla@linaro.org
  15 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  16 ---
  17  drivers/nvmem/brcm_nvram.c | 90 ++++++++++++++++++++++++++++++++++++++
  18  1 file changed, 90 insertions(+)
  19
  20 --- a/drivers/nvmem/brcm_nvram.c
  21 +++ b/drivers/nvmem/brcm_nvram.c
  22 @@ -6,12 +6,26 @@
  23  #include <linux/io.h>
  24  #include <linux/mod_devicetable.h>
  25  #include <linux/module.h>
  26 +#include <linux/nvmem-consumer.h>
  27  #include <linux/nvmem-provider.h>
  28  #include <linux/platform_device.h>
  29 +#include <linux/slab.h>
  30 +
  31 +#define NVRAM_MAGIC                    "FLSH"
  32
  33  struct brcm_nvram {
  34         struct device *dev;
  35         void __iomem *base;
  36 +       struct nvmem_cell_info *cells;
  37 +       int ncells;
  38 +};
  39 +
  40 +struct brcm_nvram_header {
  41 +       char magic[4];
  42 +       __le32 len;
  43 +       __le32 crc_ver_init;    /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
  44 +       __le32 config_refresh;  /* 0:15 sdram_config, 16:31 sdram_refresh */
  45 +       __le32 config_ncdl;     /* ncdl values for memc */
  46  };
  47
  48  static int brcm_nvram_read(void *context, unsigned int offset, void *val,
  49 @@ -26,6 +40,75 @@ static int brcm_nvram_read(void *context
  50         return 0;
  51  }
  52
  53 +static int brcm_nvram_add_cells(struct brcm_nvram *priv, uint8_t *data,
  54 +                               size_t len)
  55 +{
  56 +       struct device *dev = priv->dev;
  57 +       char *var, *value, *eq;
  58 +       int idx;
  59 +
  60 +       priv->ncells = 0;
  61 +       for (var = data + sizeof(struct brcm_nvram_header);
  62 +            var < (char *)data + len && *var;
  63 +            var += strlen(var) + 1) {
  64 +               priv->ncells++;
  65 +       }
  66 +
  67 +       priv->cells = devm_kcalloc(dev, priv->ncells, sizeof(*priv->cells), GFP_KERNEL);
  68 +       if (!priv->cells)
  69 +               return -ENOMEM;
  70 +
  71 +       for (var = data + sizeof(struct brcm_nvram_header), idx = 0;
  72 +            var < (char *)data + len && *var;
  73 +            var = value + strlen(value) + 1, idx++) {
  74 +               eq = strchr(var, '=');
  75 +               if (!eq)
  76 +                       break;
  77 +               *eq = '\0';
  78 +               value = eq + 1;
  79 +
  80 +               priv->cells[idx].name = devm_kstrdup(dev, var, GFP_KERNEL);
  81 +               if (!priv->cells[idx].name)
  82 +                       return -ENOMEM;
  83 +               priv->cells[idx].offset = value - (char *)data;
  84 +               priv->cells[idx].bytes = strlen(value);
  85 +       }
  86 +
  87 +       return 0;
  88 +}
  89 +
  90 +static int brcm_nvram_parse(struct brcm_nvram *priv)
  91 +{
  92 +       struct device *dev = priv->dev;
  93 +       struct brcm_nvram_header header;
  94 +       uint8_t *data;
  95 +       size_t len;
  96 +       int err;
  97 +
  98 +       memcpy_fromio(&header, priv->base, sizeof(header));
  99 +
 100 +       if (memcmp(header.magic, NVRAM_MAGIC, 4)) {
 101 +               dev_err(dev, "Invalid NVRAM magic\n");
 102 +               return -EINVAL;
 103 +       }
 104 +
 105 +       len = le32_to_cpu(header.len);
 106 +
 107 +       data = kcalloc(1, len, GFP_KERNEL);
 108 +       memcpy_fromio(data, priv->base, len);
 109 +       data[len - 1] = '\0';
 110 +
 111 +       err = brcm_nvram_add_cells(priv, data, len);
 112 +       if (err) {
 113 +               dev_err(dev, "Failed to add cells: %d\n", err);
 114 +               return err;
 115 +       }
 116 +
 117 +       kfree(data);
 118 +
 119 +       return 0;
 120 +}
 121 +
 122  static int brcm_nvram_probe(struct platform_device *pdev)
 123  {
 124         struct nvmem_config config = {
 125 @@ -35,6 +118,7 @@ static int brcm_nvram_probe(struct platf
 126         struct device *dev = &pdev->dev;
 127         struct resource *res;
 128         struct brcm_nvram *priv;
 129 +       int err;
 130
 131         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 132         if (!priv)
 133 @@ -46,7 +130,13 @@ static int brcm_nvram_probe(struct platf
 134         if (IS_ERR(priv->base))
 135                 return PTR_ERR(priv->base);
 136
 137 +       err = brcm_nvram_parse(priv);
 138 +       if (err)
 139 +               return err;
 140 +
 141         config.dev = dev;
 142 +       config.cells = priv->cells;
 143 +       config.ncells = priv->ncells;
 144         config.priv = priv;
 145         config.size = resource_size(res);
 146