[PATCH V2] nvmem: brcm_nvram: parse NVRAM content into NVMEM cells

[Srinivas Kandagatla]

On 20/12/2021 18:44, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal at 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 at milecki.pl>
> ---

thanks for reminding about, it seems to be lost in my emails.

Applied thanks,

--srini
> V2: Drop dev_info() calls I used for debugging
> ---
>   drivers/nvmem/brcm_nvram.c | 90 ++++++++++++++++++++++++++++++++++++++
>   1 file changed, 90 insertions(+)
> 
> diff --git a/drivers/nvmem/brcm_nvram.c b/drivers/nvmem/brcm_nvram.c
> index bd2ecaaf4585..439f00b9eef6 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 +40,75 @@ 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++;
> +	}
> +
> +	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;
> +
> +		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 +118,7 @@ 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 +130,13 @@ 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);
>