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Subject[PATCH] nvmem: brcm_nvram: parse NVRAM content into NVMEM cells
Date
From: Rafał Miłecki <rafal@milecki.pl>

NVRAM consist of header and NUL separated key-value pairs. Parse it and
create NVMEM cell for every key-value entry.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
drivers/nvmem/brcm_nvram.c | 93 ++++++++++++++++++++++++++++++++++++++
1 file changed, 93 insertions(+)

diff --git a/drivers/nvmem/brcm_nvram.c b/drivers/nvmem/brcm_nvram.c
index bd2ecaaf4585..01ad96c52809 100644
--- a/drivers/nvmem/brcm_nvram.c
+++ b/drivers/nvmem/brcm_nvram.c
@@ -6,12 +6,26 @@
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define NVRAM_MAGIC "FLSH"

struct brcm_nvram {
struct device *dev;
void __iomem *base;
+ struct nvmem_cell_info *cells;
+ int ncells;
+};
+
+struct brcm_nvram_header {
+ char magic[4];
+ __le32 len;
+ __le32 crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
+ __le32 config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */
+ __le32 config_ncdl; /* ncdl values for memc */
};

static int brcm_nvram_read(void *context, unsigned int offset, void *val,
@@ -26,6 +40,78 @@ static int brcm_nvram_read(void *context, unsigned int offset, void *val,
return 0;
}

+static int brcm_nvram_add_cells(struct brcm_nvram *priv, uint8_t *data,
+ size_t len)
+{
+ struct device *dev = priv->dev;
+ char *var, *value, *eq;
+ int idx;
+
+ priv->ncells = 0;
+ for (var = data + sizeof(struct brcm_nvram_header);
+ var < (char *)data + len && *var;
+ var += strlen(var) + 1) {
+ priv->ncells++;
+ }
+ dev_info(dev, "ncells:%d", priv->ncells);
+
+ priv->cells = devm_kcalloc(dev, priv->ncells, sizeof(*priv->cells), GFP_KERNEL);
+ if (!priv->cells)
+ return -ENOMEM;
+
+ for (var = data + sizeof(struct brcm_nvram_header), idx = 0;
+ var < (char *)data + len && *var;
+ var = value + strlen(value) + 1, idx++) {
+ eq = strchr(var, '=');
+ if (!eq)
+ break;
+ *eq = '\0';
+ value = eq + 1;
+
+ dev_info(dev, "%s: %s", var, value);
+
+ priv->cells[idx].name = devm_kstrdup(dev, var, GFP_KERNEL);
+ if (!priv->cells[idx].name)
+ return -ENOMEM;
+ priv->cells[idx].offset = value - (char *)data;
+ priv->cells[idx].bytes = strlen(value);
+ }
+
+ return 0;
+}
+
+static int brcm_nvram_parse(struct brcm_nvram *priv)
+{
+ struct device *dev = priv->dev;
+ struct brcm_nvram_header header;
+ uint8_t *data;
+ size_t len;
+ int err;
+
+ memcpy_fromio(&header, priv->base, sizeof(header));
+
+ if (memcmp(header.magic, NVRAM_MAGIC, 4)) {
+ dev_err(dev, "Invalid NVRAM magic\n");
+ return -EINVAL;
+ }
+
+ len = le32_to_cpu(header.len);
+
+ data = kcalloc(1, len, GFP_KERNEL);
+ memcpy_fromio(data, priv->base, len);
+ data[len - 1] = '\0';
+
+ err = brcm_nvram_add_cells(priv, data, len);
+ if (err) {
+ dev_err(dev, "Failed to add cells: %d\n", err);
+ return err;
+ }
+
+ kfree(data);
+
+ return 0;
+}
+
static int brcm_nvram_probe(struct platform_device *pdev)
{
struct nvmem_config config = {
@@ -35,6 +121,7 @@ static int brcm_nvram_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct resource *res;
struct brcm_nvram *priv;
+ int err;

priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
@@ -46,7 +133,13 @@ static int brcm_nvram_probe(struct platform_device *pdev)
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);

+ err = brcm_nvram_parse(priv);
+ if (err)
+ return err;
+
config.dev = dev;
+ config.cells = priv->cells;
+ config.ncells = priv->ncells;
config.priv = priv;
config.size = resource_size(res);

--
2.31.1
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