[PATCH 2/2] wifi: mt76: add support for providing eeprom in nvmem cells

[Daniel Golle]

On Sat, Jul 08, 2023 at 08:29:36PM +0200, Christian Marangi wrote:
> Add support for providing eeprom in nvmem cells by adding nvmem cell as
> an alternative source for mt76_get_of_eeprom().
> 
> Nvmem cells will follow standard nvmem cell definition and needs to be
> called 'eeprom' to be correctly identified.
> 
> Signed-off-by: Christian Marangi <ansuelsmth at gmail.com>

Reviewed-by: Daniel Golle <daniel at makrotopia.org>
Tested-by: Daniel Golle <daniel at makrotopia.org>

> ---
>  drivers/net/wireless/mediatek/mt76/eeprom.c | 38 ++++++++++++++++++++-
>  1 file changed, 37 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/eeprom.c b/drivers/net/wireless/mediatek/mt76/eeprom.c
> index c3a762074be8..36564930aef1 100644
> --- a/drivers/net/wireless/mediatek/mt76/eeprom.c
> +++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
> @@ -6,6 +6,7 @@
>  #include <linux/of_net.h>
>  #include <linux/mtd/mtd.h>
>  #include <linux/mtd/partitions.h>
> +#include <linux/nvmem-consumer.h>
>  #include <linux/etherdevice.h>
>  #include "mt76.h"
>  
> @@ -105,6 +106,37 @@ static int mt76_get_of_epprom_from_mtd(struct mt76_dev *dev, void *eep, int offs
>  #endif
>  }
>  
> +static int mt76_get_of_epprom_from_nvmem(struct mt76_dev *dev, void *eep, int len)
> +{
> +	struct device_node *np = dev->dev->of_node;
> +	struct nvmem_cell *cell;
> +	const void *data;
> +	size_t retlen;
> +	int ret = 0;
> +
> +	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) {
> +		ret = -EINVAL;
> +		goto exit;
> +	}
> +
> +	memcpy(eep, data, len);
> +
> +exit:
> +	kfree(data);
> +
> +	return ret;
> +}
> +
>  int mt76_get_of_eeprom(struct mt76_dev *dev, void *eep, int offset, int len)
>  {
>  	struct device_node *np = dev->dev->of_node;
> @@ -117,7 +149,11 @@ int mt76_get_of_eeprom(struct mt76_dev *dev, void *eep, int offset, int len)
>  	if (!ret)
>  		return 0;
>  
> -	return mt76_get_of_epprom_from_mtd(dev, eep, offset, len);
> +	ret = mt76_get_of_epprom_from_mtd(dev, eep, offset, len);
> +	if (!ret)
> +		return 0;
> +
> +	return mt76_get_of_epprom_from_nvmem(dev, eep, len);
>  }
>  EXPORT_SYMBOL_GPL(mt76_get_of_eeprom);
>  
> -- 
> 2.40.1
> 
>