Re: [PATCH net-next v4 5/8] mfd: zl3073x: Add functions to work with register mailboxes

[Ivan Vecera]

On 24. 04. 25 9:18 odp., Andrew Lunn wrote:
> > During taking 613cbb91e9ce ("media: Add MIPI CCI register access helper
> > functions") approach I found they are using for these functions u64
> > regardless of register size... Just to accommodate the biggest
> > possible value. I know about weakness of 'void *' usage but u64 is not
> > also ideal as the caller is forced to pass always 8 bytes for reading
> > and forced to reserve 8 bytes for each read value on stack.
>
> In this device, how are the u48s used? Are they actually u48s, or are
> they just u8[6], for example a MAC address? The network stack has lots
> of functions like:
>
> eth_hw_addr_set(struct net_device *dev, const u8 *addr)

u48 registers always represent 48bit integer... they read from device 
using bulk read as big-endian 48bit int. The same is valid also for u16
and u32.

Ivan