Hi Adam,
On Wed, 13 Feb 2019 at 05:14, Adam Ford aford173@gmail.com wrote:
On Mon, Jan 21, 2019 at 12:26 PM sjg@google.com wrote:
On Wed, 16 Jan 2019 at 12:40, Simon Goldschmidt simon.k.r.goldschmidt@gmail.com wrote:
Improve some things in the documentation of OF_PLATDATA that I found while porting socfgpa_gen5 to it.
Thanks for doing that. I actually learned a bit. :-)
This may be more directed at Simon, but it seems like many platforms are limited in SPL and OF_PLATDATA might be a great feature to get more drivers supporting device tree booting without as much overhead.
From how the documentation reads, it seems like the drivers may not necessarily support OF_PLATDATA by default. I've been struggling trying to enable basic functions (like serial via 16550 driver) because the platform data generated doesn't necessarily match the platform data I use to start the serial device. I would like to migrate from using manually entered platform data to using OF_PLATDATA to reduce the overhead.
A few things I noticed are that the generated device names correspond to the names listed in the 'compatible' flag and there doesn't seem to be a good way to link them to the actual driver name.
Yes, that is the job of the code. See for example rockchip_serial_probe() which copies the platform data out of the of-platdata struct and into the normal one.
I see a few drivers that check for OF_PLATDATA, but I am not seeing many people actually utilize this feature. Any suggestions on how to one might migrate a driver (like serial) which already supports OF_CONTROL in u-boot, but the generated platdata doesn't boot in SPL?
You can have a look at serial_rockchip as an example. If you don't have a JTAG unit I suggest enabling the debug UART so you can debug what goes wrong when it cannot find the serial device.
Regards, Simon