My particular issue is downloading the bluetooth firmware to the AP6210. With the 3.4 kernel I can toggle the BT_REST pin (via gpio PH18) and then open a serial connection (via uart2) and download. This works reliably. With the 3.19 kernel the AP6210 didn't respond.
I've just found that if I hold BT_REST low, then open the serial connection, then release BT_REST, that the download will work. This is not an ideal solution because the Broadcom download program can't be used and the replacement program is kernel release specific. I'm wondering if the TX line from uart2 is floating before the port is opened and this is confusing the AP6210 and it's misdetecting the baud rate. The sun71-a20-cubietruck.dtb has pullup disabled for the uart2 pins. This differs from the 3.4 kernel script.bin which has the pullup set to 1. I've tried changing the .dtb file so the pullup is 1 but this didn't help. Perhaps my .dts changes are wrong. Can anybody provide a link to a good devicetree syntax manual ? Or where I can find the .dtb parsing code to see if allwinner.pull is used when allwinner,function is set to a mux value ? Or if the uart pin specs are loaded before the uart is enabled ? Thanks, Steven -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
