From: Rafał Miłecki <rafal@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxxx
Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
Cc: bcm-kernel-feedback-list@xxxxxxxxxxxx
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
[Added an export for modules potentially using the init symbol]
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
This affects the ARM SoC in my case, but previous patches to
this driver were merged through the MIPS tree so I expect
Thomas to pick this up, if you prefer the SoC tree please
tell me and I will resend.
---
drivers/firmware/broadcom/bcm47xx_nvram.c | 18 ++++++++++++++++++
drivers/nvmem/brcm_nvram.c | 3 +++
include/linux/bcm47xx_nvram.h | 6 ++++++
3 files changed, 27 insertions(+)
diff --git a/drivers/firmware/broadcom/bcm47xx_nvram.c b/drivers/firmware/broadcom/bcm47xx_nvram.c
index bd235833b687..5f47dbf4889a 100644
--- a/drivers/firmware/broadcom/bcm47xx_nvram.c
+++ b/drivers/firmware/broadcom/bcm47xx_nvram.c
@@ -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
diff --git a/drivers/nvmem/brcm_nvram.c b/drivers/nvmem/brcm_nvram.c
index 4441daa20965..34130449f2d2 100644
--- a/drivers/nvmem/brcm_nvram.c
+++ b/drivers/nvmem/brcm_nvram.c
@@ -3,6 +3,7 @@
* Copyright (C) 2021 Rafał Miłecki <rafal@xxxxxxxxxx>
*/
+#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;
diff --git a/include/linux/bcm47xx_nvram.h b/include/linux/bcm47xx_nvram.h
index 53b31f69b74a..7615f8d7b1ed 100644
--- a/include/linux/bcm47xx_nvram.h
+++ b/include/linux/bcm47xx_nvram.h
@@ -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;
--
2.34.1
