On 02/06/2017 06:04 AM, Andrew Lunn wrote:
>> +/**
>> + * mdio_register_board_info - register MDIO devices for a given board
>> + * @info: array of devices descriptors
>> + * @n: number of descriptors provided
>> + * Context: can sleep
>> + *
>> + * The board info passed can be marked with __initdata but be pointers
>> + * such as platform_data etc. are copied as-is
>> + */
>> +int mdiobus_register_board_info(const struct mdio_board_info *info,
>> + unsigned int n)
>> +{
>> + struct mdio_board_entry *be;
>> + unsigned int i;
>> +
>> + be = kcalloc(n, sizeof(*be), GFP_KERNEL);
>> + if (!be)
>> + return -ENOMEM;
>> +
>> + for (i = 0; i < n; i++, be++, info++) {
>> + memcpy(&be->board_info, info, sizeof(*info));
>> + mutex_lock(&mdio_board_lock);
>> + list_add_tail(&be->list, &mdio_board_list);
>> + mutex_unlock(&mdio_board_lock);
>> + }
>> +
>> + return 0;
>
> Hi Florian
>
> I've recently been playing with a hot-pluggable SPI bus controller. It
> is a USB device, hence can come and go. On the SPI bus i have an
> SRAM. On order to instantiate the MTD device, i need SPI board info. I
> cannot add the board info until after the SPI bus master appears,
> since i need to know its ID to fill in the board info. At the moment,
> i have udev script which when the SPI bus master appears loads a
> little kernel module which registers the board info.
>
> Such a scheme will not work here. You need to iterate the list of MDIO
> devices at the end of mdiobus_register_board_info() to see if the just
> registered board info applies to any existing MDIO bus.
I was thinking when mdio_device_register() is called, see if there is a
matching board info for it, and if so, assign its platform_data
accordingly. In the case where mdiobus_register_with_board
>
> I don't think we yet have any hardware which would do this. But there
> have been patches to one of the USB-Ethernet dongles to allow it run
> without a PHY. My guess is, to allow an SFP module. But it is not too
> big a step for somebody to make a USB attached Ethernet switch.
>
> Maybe consider adding this functionality? Also an unregister call?
Sure, makes sense.
--
Florian
