SDIO_CLASS_UART and Globalsat SD-502 SDIO GPS

[Michael Hunold <hunold@linuxtv.org>]

Hello all,

I know that this is ancient hardware, but I got my hands on a Globalsat
SD-502 SDIO GPS receiver which I'd like to use.

After adding SDIO_UART ("SDIO UART/GPS class support") the card was
correctly recognized, but unfortunately, I just received the warning

"mmc1:0000:1: need info on UART class basic setup"

on the console.

After looking at the code, it seems that support for SDIO_CLASS_UART is
simply not there (yet). :-(

There are a few screenshots in the manual that suggest that the Windows
software adds a virtual COM port with 4800bps transfer rate.

According to the datasheet, it is using "Bsquare SDIO Now!". It's
unclear if this is totally proprietary or not.

I google'd around for a few hours but I cannot find out what exactly is
missing here to get the devie running, assuming that it is a device
compatbile to SDIO_UART.

For gettting deeper into the topic, I added some debug prints to
sdio_uart_probe() and printed out the sdio_func_tuple array.

Unfortunately, only two identical tuples (code 0x21, first byte 0x0c,
second byte 0x00) are available. According to the SDIO specific
extensions, this 0x21 (= CISTPL_FUNCID) tuple should be followed by 0x22
(= CISTPL_FUNCE) but for me it isn't.

Here I am currently stuck. Does anybody know how to add support for
SDIO_CLASS_UART? Any hints are very appreciated.

CU
Michael.