Hi,
On 22/09/2022 20:51, Edoardo Tomelleri wrote:
Hello, Il giorno gio 22 set 2022 alle ore 18:51 Neil Armstrong neil.armstrong@linaro.org ha scritto:
Hi,
Sorry for the delay...
No problem, don't worry
Looks good !
If someone can test it ? otherwise I'll take it for next release.
...does it count if I've tested it? I have a radxa zero board (S905Y2 chip), this started as an experimentation with editing register values in memory "for fun" and I decided to try to make a patch out of it.
Yes it's perfect, thanks a lot for the test results !
I do not have an oscilloscope so I can not accurately measure the baud rate, but the logic is the same as in linux and using an USB to UART (PL2303) adapter console input and loady command work fine. I've just repeated a small test: I'm using picocom and lrzsz in ymodem mode under WSL, the usb adapter is forwarded to WSL using usbip, but this should not change anything at this kind of speed (I hope). Here are some results sending a 1 MB test file (created once from /dev/urandom): picocom v3.1
port is : /dev/ttyUSB0 flowcontrol : none baudrate is : 115200 parity is : none databits are : 8 stopbits are : 1 [...] send_cmd is : sz --ymodem -vv receive_cmd is : rz -vv -E [...] @115200 Bytes Sent:1048576 BPS:7762 @230400 Bytes Sent:1048576 BPS:16372 @460800 Bytes Sent:1048576 BPS:26681 @500000 Bytes Sent:1048576 BPS:27689 @500000 (2nd run) Bytes Sent:1048576 BPS:27207
At this point I stopped testing, I think my adapter is not good enough and that the logic is correct (I've read amlogic's public datasheets [1], but I've not found a formula specified there), Reading address (for hardware device UARTAO1, that _of course_ is not listed there) md.l 0xff803014 1 ff803014: 0180000f This corresponds to REG5 of device UARTAO1, with bits 24 (USE_XTAL_CLK), 23 (use new baud rate) set, and bits 27 and 26 clear (so 24 MHz crystal clock is divided by 3), NEW_BAUD_RATE is f, so baud rate should be (8 MHz / (15 + 1)) = 500K.
Other than that, I noticed that setting the env variable baudrate is restricted to values allowed in a compile time config, loady is not and loady ignores the return value of meson_serial_setbrg (it returns -EINVAL if for example a baudrate higher than 8'000'000 is requested), here's a test (with env variable baudrate=500000): => loady 0x01000000 8000001 ## Switch baudrate to 8000001 bps and press ENTER ... ## Ready for binary (ymodem) download to 0x01000000 at 8000001 bps... C *** file: ./dest $ sz --ymodem -vv ./dest Sending: dest Bytes Sent:1048576 BPS:27781 Sending: Ymodem sectors/kbytes sent: 0/ 0k Transfer complete
*** exit status: 0 *** ## Total Size = 0x00100000 = 1048576 Bytes ## Start Addr = 0x01000000 ## Switch baudrate to 500000 bps and press ESC ... =>
setbrg fails, the baud rate register is left at the 500'000 setting and that's it. I think the "for fun" experiment has gone a bit too far.
Edoardo [1] https://dl.radxa.com/zero/docs/hw/IO%20Interface%ef%bc%8dS905Y2%20Datasheet....
I'll apply it then.
Acked-by: Neil Armstrong narmstrong@baylibre.com
Please send more patches with such quality !
Thanks, Neil