Commit a5be5ce0 authored by Rafał Miłecki's avatar Rafał Miłecki Committed by Florian Fainelli
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firmware/nvram: bcm47xx: support init from IO memory 



Provide NVMEM content to the NVRAM driver from a simple
memory resource. This is necessary to use NVRAM in a memory-
mapped flash device. Patch taken from OpenWrts development
tree.

This patch makes it possible to use memory-mapped NVRAM
on the D-Link DWL-8610AP and the D-Link DIR-890L.

Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@vger.kernel.org
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: default avatarRafał Miłecki <rafal@milecki.pl>
[Added an export for modules potentially using the init symbol]
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20221103082529.359084-1-linus.walleij@linaro.org


Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
parent 117bd98d

drivers/firmware/broadcom/bcm47xx_nvram.c

+18 −0
Original line number Diff line number Diff line
@@ -110,6 +110,24 @@ static int bcm47xx_nvram_find_and_copy(void __iomem *flash_start, size_t res_siz 
	return 0;

}



int bcm47xx_nvram_init_from_iomem(void __iomem *nvram_start, size_t res_size)

{

	if (nvram_len) {

		pr_warn("nvram already initialized\n");

		return -EEXIST;

	}



	if (!bcm47xx_nvram_is_valid(nvram_start)) {

		pr_err("No valid NVRAM found\n");

		return -ENOENT;

	}



	bcm47xx_nvram_copy(nvram_start, res_size);



	return 0;

}

EXPORT_SYMBOL_GPL(bcm47xx_nvram_init_from_iomem);



/*

 * On bcm47xx we need access to the NVRAM very early, so we can't use mtd

 * subsystem to access flash. We can't even use platform device / driver to

drivers/nvmem/brcm_nvram.c

+3 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>

 */



#include <linux/bcm47xx_nvram.h>

#include <linux/io.h>

#include <linux/mod_devicetable.h>

#include <linux/module.h>
@@ -136,6 +137,8 @@ static int brcm_nvram_probe(struct platform_device *pdev) 
	if (err)

		return err;



	bcm47xx_nvram_init_from_iomem(priv->base, resource_size(res));



	config.dev = dev;

	config.cells = priv->cells;

	config.ncells = priv->ncells;

include/linux/bcm47xx_nvram.h

+6 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/vmalloc.h>



#ifdef CONFIG_BCM47XX_NVRAM

int bcm47xx_nvram_init_from_iomem(void __iomem *nvram_start, size_t res_size);

int bcm47xx_nvram_init_from_mem(u32 base, u32 lim);

int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len);

int bcm47xx_nvram_gpio_pin(const char *name);
@@ -20,6 +21,11 @@ static inline void bcm47xx_nvram_release_contents(char *nvram) 
	vfree(nvram);

};

#else

static inline int bcm47xx_nvram_init_from_iomem(void __iomem *nvram_start,

						size_t res_size)

{

	return -ENOTSUPP;

}

static inline int bcm47xx_nvram_init_from_mem(u32 base, u32 lim)

{

	return -ENOTSUPP;