[PATCH] wifi: rt2x00: add nvmem eeprom support

[PATCH] wifi: rt2x00: add nvmem eeprom support

[Rosen Penev]

Some embedded platforms have eeproms located in flash. Add nvmem support
to handle this. Support is added for PCI and SOC backends.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 .../net/wireless/ralink/rt2x00/rt2800lib.c    | 31 +++++++++++++++++++
 .../net/wireless/ralink/rt2x00/rt2800lib.h    |  2 ++
 .../net/wireless/ralink/rt2x00/rt2800pci.c    |  3 ++
 .../net/wireless/ralink/rt2x00/rt2800soc.c    |  6 +++-
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
index af19153697ed..f0d8b5140e1a 100644
--- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
@@ -24,6 +24,7 @@
 #include <linux/clk.h>
 #include <linux/crc-ccitt.h>
 #include <linux/module.h>
+#include <linux/nvmem-consumer.h>
 
 #include "rt2x00.h"
 #include "rt2800lib.h"
@@ -10961,6 +10962,36 @@ int rt2800_read_eeprom_efuse(struct rt2x00_dev *rt2x00dev)
 }
 EXPORT_SYMBOL_GPL(rt2800_read_eeprom_efuse);
 
+int rt2800_read_eeprom_nvmem(struct rt2x00_dev *rt2x00dev)
+{
+	struct device_node *np = rt2x00dev->dev->of_node;
+	unsigned int len = rt2x00dev->ops->eeprom_size;
+	struct nvmem_cell *cell;
+	const void *data;
+	size_t retlen;
+
+	cell = of_nvmem_cell_get(np, "eeprom");
+	if (IS_ERR(cell))
+		return PTR_ERR(cell);
+
+	data = nvmem_cell_read(cell, &retlen);
+	nvmem_cell_put(cell);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	if (retlen != len) {
+		dev_err(rt2x00dev->dev, "invalid eeprom size, required: 0x%04x\n", len);
+		kfree(data);
+		return -EINVAL;
+	}
+
+	memcpy(rt2x00dev->eeprom, data, len);
+	kfree(data);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rt2800_read_eeprom_nvmem);
+
 static u8 rt2800_get_txmixer_gain_24g(struct rt2x00_dev *rt2x00dev)
 {
 	u16 word;
diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800lib.h b/drivers/net/wireless/ralink/rt2x00/rt2800lib.h
index 620a3d9872ce..a3c3a751f57e 100644
--- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.h
+++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.h
@@ -248,6 +248,8 @@ void rt2800_disable_radio(struct rt2x00_dev *rt2x00dev);
 int rt2800_efuse_detect(struct rt2x00_dev *rt2x00dev);
 int rt2800_read_eeprom_efuse(struct rt2x00_dev *rt2x00dev);
 
+int rt2800_read_eeprom_nvmem(struct rt2x00_dev *rt2x00dev);
+
 int rt2800_probe_hw(struct rt2x00_dev *rt2x00dev);
 
 void rt2800_get_key_seq(struct ieee80211_hw *hw,
diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800pci.c b/drivers/net/wireless/ralink/rt2x00/rt2800pci.c
index 8c2e7b388832..c7b853195722 100644
--- a/drivers/net/wireless/ralink/rt2x00/rt2800pci.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2800pci.c
@@ -274,6 +274,9 @@ static int rt2800pci_read_eeprom(struct rt2x00_dev *rt2x00dev)
 {
 	int retval;
 
+	if (!rt2800_read_eeprom_nvmem(rt2x00dev))
+		return 0;
+
 	if (rt2800pci_efuse_detect(rt2x00dev))
 		retval = rt2800pci_read_eeprom_efuse(rt2x00dev);
 	else
diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800soc.c b/drivers/net/wireless/ralink/rt2x00/rt2800soc.c
index 24549072e324..4952afe02b62 100644
--- a/drivers/net/wireless/ralink/rt2x00/rt2800soc.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2800soc.c
@@ -89,8 +89,12 @@ static int rt2800soc_set_device_state(struct rt2x00_dev *rt2x00dev,
 
 static int rt2800soc_read_eeprom(struct rt2x00_dev *rt2x00dev)
 {
-	void __iomem *base_addr = ioremap(0x1F040000, EEPROM_SIZE);
+	void __iomem *base_addr;
 
+	if (!rt2800_read_eeprom_nvmem(rt2x00dev))
+		return 0;
+
+	base_addr = ioremap(0x1F040000, EEPROM_SIZE);
 	if (!base_addr)
 		return -ENOMEM;
 
-- 
2.51.1

Re: [PATCH] wifi: rt2x00: add nvmem eeprom support

[Johannes Berg]

Please always tag patches with the tree they should apply to (e.g.
'[PATCH wireless-next]') and make sure they actually _do_ apply.

johannes

Re: [PATCH] wifi: rt2x00: add nvmem eeprom support

[Rosen Penev]

On Mon, Oct 27, 2025 at 1:13 AM Johannes Berg <johannes@sipsolutions.net> wrote:
>
> Please always tag patches with the tree they should apply to (e.g.
> '[PATCH wireless-next]') and make sure they actually _do_ apply.
That's embarrassing. Will resend with both issues fixed.
>
> johannes