Commit 6e977eaa authored by Rafał Miłecki's avatar Rafał Miłecki Committed by Greg Kroah-Hartman
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nvmem: brcm_nvram: parse NVRAM content into NVMEM cells 



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

Signed-off-by: default avatarRafał Miłecki <rafal@milecki.pl>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220225175822.8293-3-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cd936301

drivers/nvmem/brcm_nvram.c

+90 −0
Original line number Diff line number Diff line
@@ -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);