基于Zephyr的i.MX95EVK M核GPIO_IO16切换故障求助

我在使用i.MX95EVK的M核切换GPIO_IO16引脚时遇到问题：该引脚默认复用为SAI3，我通过pinmux将其重映射为gpio_io_bit_16，同时删除SAI3节点避免冲突，但执行gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE)时触发总线错误，错误日志如下：

*** Booting Zephyr OS build v4.1.0-3508-g8b1f06af052f ***
Entered Main Function
[00:00:00.006,000] <err> os: ***** BUS FAULT *****
[00:00:00.012,000] <err> os:   Precise data bus error
[00:00:00.018,000] <err> os:   BFAR Address: 0x443c0254
[00:00:00.024,000] <err> os: r0/a1:  0x00000001  r1/a2:  0x200003a9  r2/a3:  0x00000000
[00:00:00.032,000] <err> os: r3/a4:  0x443c0000 r12/ip:  0x00001eb9 r14/lr:  0x0000071d
[00:00:00.041,000] <err> os:  xpsr:  0x01000000
[00:00:00.046,000] <err> os: Faulting instruction address (r15/pc): 0x00000732
[00:00:00.054,000] <err> os: >>> ZEPHYR FATAL ERROR 25: Unknown error on CPU 0
[00:00:00.062,000] <err> os: Current thread: 0x20000198 (unknown)
[00:00:00.069,000] <err> os: Halting system

为排查错误，我做了以下操作：

• 修改SM（M33）配置文件mx95evk.cfg，将GPIO2、PIN_GPIO_IO16、IOMUXC、IOMUX_GPR、PERLPI_GPIO2的所有权移至M核
• 尝试定义gpio-hog，但无效
• 在A核的DTS中禁用了gpio2和SAI3

以下是相关文件内容：

DTS覆盖文件 #

/* boards/imx95_evk_mimx9596_m7.overlay */

#include <zephyr/dt-bindings/rdc/imx_rdc.h>

/ {
    aliases {
        led0 = &user_led;
    };

    leds {
        compatible = "gpio-leds";
        user_led: led_0 {
            gpios = <&gpio2 16 GPIO_ACTIVE_HIGH>;
            label = "User LED";
        };
    };
};

&pinctrl {
    gpio2_io16_default: gpio2_io16_default {
        pinmux = <&iomuxc_gpio_io16_gpio_io_bit_gpio2_io_bit16>;
        bias-pull-down;
        slew-rate = "slightly-fast";
        drive-strength = "x4";
    };
};

/*
&iomuxc {
    rdc = <
        RDC_DOMAIN_PERM(M7_DOMAIN_ID, RDC_DOMAIN_PERM_RW)
    >;
    status = "okay";
};
*/

&gpio1 {
    status = "disabled";
};

&gpio2 {
    pinmux = <&iomuxc_gpio_io16_gpio_io_bit_gpio2_io_bit16>;
    
    /* Declare holes so pin 16 -> index 0 */
    gpio-reserved-ranges = <0 16>;
    /*rdc = <RDC_DOMAIN_PERM(M7_DOMAIN_ID, RDC_DOMAIN_PERM_RW)>;*/
    status = "okay";
};

/delete-node/ &sai3_default;
/delete-node/ &sai3;

main.c文件 #

#include <zephyr/kernel.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/sys/printk.h>


#include <zephyr/sys/util.h>
#include <zephyr/sys/sys_io.h>  // sys_read32/sys_write32

#define PAD_CTL_GPIO_IO16 0x443C0254u

static void pad_probe(void)
{
    volatile uint32_t tmp;

    /* Try a safe READ first. If this bus-faults, M7 has no read permission. */
    tmp = sys_read32(PAD_CTL_GPIO_IO16);

    /* Try a write/restore. If only reads are allowed, this will bus-fault. */
    sys_write32(tmp, PAD_CTL_GPIO_IO16);
}


/* The devicetree node identifier for the "led0" alias. */
#define LED0_NODE DT_ALIAS(led0)

#if !DT_NODE_HAS_STATUS(LED0_NODE, okay)
#error "Unsupported board: led0 devicetree alias is not defined"
#endif

static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(LED0_NODE, gpios);

int main(void)
{
    int ret;

    printk("Entered Main Function\n");

    if (!device_is_ready(led.port)) {
        printk("Error: LED device %s is not ready\n", led.port->name);
        return -1;
    }

    pad_probe();

    ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);
    if (ret < 0) {
        printk("Error %d: Failed to configure LED pin\n", ret);
        return ret;
    }

    printk("Starting to blink LED on pin %d\n", led.pin);

    while (1) {
        ret = gpio_pin_toggle_dt(&led);
        if (ret < 0) {
            printk("Error %d: Failed to toggle LED\n", ret);
            return ret;
        }
        printk("Toggled GPIO\n");
        k_msleep(1000);
    }

    return 0;
}

prj.conf文件 #

CONFIG_GPIO=y
CONFIG_PINCTRL=y
CONFIG_PRINTK=y
CONFIG_STDOUT_CONSOLE=y
CONFIG_LOG=y
CONFIG_LOG_MODE_IMMEDIATE=y

内容的提问来源于stack exchange，提问作者Deepshika