Incorrect behavior for add_program_at_offset for pins > 31

[drewpo28]

Hello,

I guess the change in method 'add_program_at_offset' need to be done for board 2350 in case of used pins > 31 with pio_set_gpio_base(pio, 16);

Please remove the line - static_assert(PIO_GPIOBASE_BITS == 16, ""); // only works for gpio base being 0 or 16

static int add_program_at_offset(PIO pio, const pio_program_t *program, uint offset) {
    int rc = add_program_at_offset_check(pio, program, offset);
    if (rc != 0) return rc;
    for (uint i = 0; i < program->length; ++i) {
        uint16_t instr = program->instructions[i];
#if PICO_PIO_USE_GPIO_BASE
        if (pio_instr_bits_wait == _pio_major_instr_bits(instr) && !((_pio_arg1(instr) & 3u))) {
            // wait GPIO will include only the 5 lower bits of the GPIO number, so if the GPIO
            // base is 16 we need to flip bit 4 (which is equivalent to subtracting 16 from
            // the original number 16-47 stored as 16-31 and 0-15)
            static_assert(PIO_GPIOBASE_BITS == 16, ""); // only works for gpio base being 0 or 16
            instr ^= (uint16_t)pio_get_gpio_base(pio);
        }
#endif
        pio->instr_mem[offset + i] = pio_instr_bits_jmp != _pio_major_instr_bits(instr) ? instr : instr + offset;
    }
    uint32_t program_mask = (1u << program->length) - 1;
    _used_instruction_space[pio_get_index(pio)] |= program_mask << offset;
    return (int)offset;
}

[peterharperuk]

Please remove the line - static_assert(PIO_GPIOBASE_BITS == 16, ""); // only works for gpio base being 0 or 16

Please clarify why you think this needs to be removed. I suspect you've jumped to the wrong conclusion about what it does.

[lurch]

Yeah, I suspect you're confusing PIO_GPIOBASE_BITS (which is a constant defined here ) with pio_get_gpio_base (which is a function declared here).

[drewpo28]

Please remove the line - static_assert(PIO_GPIOBASE_BITS == 16, ""); // only works for gpio base being 0 or 16

Please clarify why you think this needs to be removed. I suspect you've jumped to the wrong conclusion about what it does.

I am using board Waveshare RP2350 PiZero.
It has following GPIO for HDMI

GPIO32 <-> DVI_D0_N
GPIO33 <-> DVI_D0_P
GPIO34 <-> DVI_D1_N
GPIO35 <-> DVI_D2_N
GPIO36 <-> DVI_D1_P
GPIO37 <-> DVI_D2_P
GPIO38 <-> DVI_CLK_P
GPIO39 <-> DVI_CLK_N

The example of code below is used to initialize hdmi and it not working without change proposed above.

pio_set_gpio_base(PIO_VIDEO, 16);
pio_remove_program(PIO_VIDEO_ADDR, &pio_program_conv_addr_HDMI, offs_prg1);
offs_prg1 = pio_add_program(PIO_VIDEO_ADDR, &pio_program_conv_addr_HDMI);

[lurch]

it not working without change proposed above.

That sounds very strange. As I pointed out above, PIO_GPIOBASE_BITS is a constant which always has the value 16 (i.e. 0x10 in hex) on RP2350, so PIO_GPIOBASE_BITS == 16 should always be true. Have you accidentally redefined PIO_GPIOBASE_BITS to some other value? Which board-header file are you using?

[drewpo28]

I am using board pico2 with redefined PICO_PIO_USE_GPIO_BASE = 1
PIO_GPIOBASE_BITS is used by default

[lurch]

Rather than setting PICO_PIO_USE_GPIO_BASE = 1 you might have more luck with setting PICO_RP2350A = 0 (which indicates that you're using a RP2350B chip).

[drewpo28]

I have tried it before without success, but will check again

[peterharperuk]

Please tell us the exact compile error you're seeing.

[drewpo28]

It compiles without errors, but there’s no video after flashing the app.

[peterharperuk]

My guess - as @lurch says - is you haven't told it you have >32 GPIOS. I can't see how removing a static assert would fix anything.

[kilograham]

if you are hitting that assert, you are probably building for RP2040 somehow. do you either specify PICO_PLATFORM=rp2350 when you build, or is it set via pico_board_cmake_set(PICO_PLATFORM, rp2350) in your board header?

Also, as mentioned before, you should not be setting PICO_PIO_USE_GPIO_BASE = 1 - having to do so is likely a result of some other configuration issue. All in all, i'd say there are issues with your board header;

[drewpo28]

Thanks for all. You are right, the issue was with board header. I have added custom definition for Waveshare RP2350 PiZero.

/*
 * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

// -----------------------------------------------------
// NOTE: THIS HEADER IS ALSO INCLUDED BY ASSEMBLER SO
//       SHOULD ONLY CONSIST OF PREPROCESSOR DIRECTIVES
// -----------------------------------------------------

// This header may be included by other board headers as "boards/waveshare_rp2350_pizero.h"

#ifndef _BOARDS_WAVESHARE_RP2350_PIZERO
#define _BOARDS_WAVESHARE_RP2350_PIZERO

pico_board_cmake_set(PICO_PLATFORM, rp2350)

// For board detection
#define RASPBERRYPI_RP2350_PIZERO

// --- RP2350 VARIANT ---
#define PICO_RP2350A 0

// --- UART ---
#ifndef PICO_DEFAULT_UART
#define PICO_DEFAULT_UART 0
#endif
#ifndef PICO_DEFAULT_UART_TX_PIN
#define PICO_DEFAULT_UART_TX_PIN 0
#endif
#ifndef PICO_DEFAULT_UART_RX_PIN
#define PICO_DEFAULT_UART_RX_PIN 1
#endif

// --- I2C ---
#ifndef PICO_DEFAULT_I2C
#define PICO_DEFAULT_I2C 0
#endif
#ifndef PICO_DEFAULT_I2C_SDA_PIN
#define PICO_DEFAULT_I2C_SDA_PIN 10
#endif
#ifndef PICO_DEFAULT_I2C_SCL_PIN
#define PICO_DEFAULT_I2C_SCL_PIN 11
#endif

// --- SPI ---
#ifndef PICO_DEFAULT_SPI
#define PICO_DEFAULT_SPI 1
#endif
#ifndef PICO_DEFAULT_SPI_SCK_PIN
#define PICO_DEFAULT_SPI_SCK_PIN 30
#endif
#ifndef PICO_DEFAULT_SPI_TX_PIN
#define PICO_DEFAULT_SPI_TX_PIN 31
#endif
#ifndef PICO_DEFAULT_SPI_RX_PIN
#define PICO_DEFAULT_SPI_RX_PIN 40
#endif
#ifndef PICO_DEFAULT_SPI_CSN_PIN
#define PICO_DEFAULT_SPI_CSN_PIN 43
#endif

// --- FLASH ---

#define PICO_BOOT_STAGE2_CHOOSE_W25Q080 1

#ifndef PICO_FLASH_SPI_CLKDIV
#define PICO_FLASH_SPI_CLKDIV 2
#endif

pico_board_cmake_set_default(PICO_FLASH_SIZE_BYTES, (4 * 1024 * 1024))
#ifndef PICO_FLASH_SIZE_BYTES
#define PICO_FLASH_SIZE_BYTES (4 * 1024 * 1024)
#endif

pico_board_cmake_set_default(PICO_RP2350_A2_SUPPORTED, 1)
#ifndef PICO_RP2350_A2_SUPPORTED
#define PICO_RP2350_A2_SUPPORTED 1
#endif

#endif

[lurch]

Glad to hear you've got things working 👍

I have added custom definition for Waveshare RP2350 PiZero.

You're welcome to submit that as a Pull Request for the benefit of other Waveshare RP2350 PiZero users 🙂