Cleanup/clarification of PIO behavior with >32 pins #2085

2024-11-21T21:32:54-06:00

kilograham commented

2024-11-21 21:32:54 -06:00

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peterharperuk (Migrated from github.com) reviewed

2024-11-22 05:12:34 -06:00

src/rp2_common/hardware_pio/include/hardware/pio.h

					
				@ -72,0 +80,4 @@

				 *

				 * On RP2350B, there are 48 pins but each PIO instance can only address 32 pins (the PIO

				 * instance either addresses pins 0-31 or 16-47 based on \ref pio_set_gpio_base). The

				 * `pio_sm_` methods that directly affect the hardware always take _real_ pin numbers in the full range, however:

Is it worth saying that sm_ methods also take real pin numbers?

Is it worth saying that sm_ methods also take _real_ pin numbers?

peterharperuk (Migrated from github.com) reviewed

2024-11-22 05:14:42 -06:00

src/rp2_common/hardware_pio/include/hardware/pio.h

					
				@ -72,0 +80,4 @@

				 *

				 * On RP2350B, there are 48 pins but each PIO instance can only address 32 pins (the PIO

				 * instance either addresses pins 0-31 or 16-47 based on \ref pio_set_gpio_base). The

				 * `pio_sm_` methods that directly affect the hardware always take _real_ pin numbers in the full range, however:

ah - you've said that below - ignore

peterharperuk (Migrated from github.com) approved these changes

2024-11-22 06:38:50 -06:00

peterharperuk (Migrated from github.com) left a comment

Looks good to me, and fixes the uart_rx example!

peterharperuk (Migrated from github.com) requested changes

2024-11-22 07:00:32 -06:00

peterharperuk (Migrated from github.com) left a comment

ah - I think pio_sm_set_pindirs_with_mask64 is shifting twice. It shifts by pio_get_gpio_base then calls pio_sm_set_pindirs_with_mask_internal which shifts again. Removing the shift from pio_sm_set_pindirs_with_mask_internal fixes this. uart_tx can be used to test this.

peterharperuk (Migrated from github.com) reviewed

2024-11-22 08:17:23 -06:00

src/rp2_common/hardware_pio/pio.c

These lines need to be removed?

peterharperuk (Migrated from github.com) approved these changes

2024-11-22 12:19:57 -06:00

peterharperuk (Migrated from github.com) left a comment

Seems to work nicely

lurch (Migrated from github.com) reviewed

2024-11-24 19:00:53 -06:00

src/rp2_common/hardware_pio/pio.c

					
				@ -265,4 +274,4 @@

				    }

				    pio->sm[sm].pinctrl = pinctrl_saved;

				    pio->sm[sm].execctrl = execctrl_saved;

				}

I'm sure this must be a stupid question, but why is line 243 doing

#ifndef pio_sm_set_pins_internal

when line 221 says

void pio_sm_set_pins_internal(PIO pio, uint sm, uint32_t pins) {

?

I'm sure this must be a stupid question, but why is line 243 doing ``` #ifndef pio_sm_set_pins_internal ``` when line 221 says ``` void pio_sm_set_pins_internal(PIO pio, uint sm, uint32_t pins) { ``` ?

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