cyw43_driver only works with SM0 #1077

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opened 2022-10-26 11:22:25 -05:00 by Lord-Lucan · 5 comments

Lord-Lucan commented

2022-10-26 11:22:25 -05:00

(Migrated from github.com)

The cyw43_driver (see cyw43_bus_pio_spi.c) only supports SM0. It tries to play nice by allocating a free PIO and requesting a SM but if it gets an SM other than 0 it doesn't work.

The workaround is to make sure that you keep SM 0 free on a PIO for this driver.

In cyw43_bus_pio_spi.c (line 263) we have code like this ....
dma_channel_configure(bus_data->dma_out, &out_config, &bus_data->pio->txf[0], tx, tx_length / 4, true);
Which is hardwiring the DMA to pio SM 0 fifo.

Have tried to fix, but not completely working yet :(

The cyw43_driver (see cyw43_bus_pio_spi.c) only supports SM0. It tries to play nice by allocating a free PIO and requesting a SM but if it gets an SM other than 0 it doesn't work. The workaround is to make sure that you keep SM 0 free on a PIO for this driver. In cyw43_bus_pio_spi.c (line 263) we have code like this .... ` dma_channel_configure(bus_data->dma_out, &out_config, &bus_data->pio->txf[0], tx, tx_length / 4, true);` Which is hardwiring the DMA to pio SM 0 fifo. Have tried to fix, but not completely working yet :(

kilograham commented

2022-10-26 11:45:11 -05:00

(Migrated from github.com)

I would thing just changing from txf[0] to txf[bus_data->pio_sm] should do it, no? (also for the other txf[0]/rxf[0])

I would thing just changing from `txf[0]` to `txf[bus_data->pio_sm]` should do it, no? (also for the other `txf[0]/rxf[0]`)

Lord-Lucan commented

2022-10-26 11:53:56 -05:00

(Migrated from github.com)

Hi, thanks for the reply. Yes tried all of that, there are other places in the code where it's hard coded as well. But it still doesn't transfer properly. So it's a bit more deep rooted. I'll take a deeper look at the weekend. At the moment I've just made sure my SM is not claiming 0.

Lord-Lucan commented

2022-10-26 11:56:16 -05:00

(Migrated from github.com)