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给跪了，GPIO设置为输出问题

大白他弟
Expert 1160 points


8148芯片，跑的是8127 appro ipnc rdk 3.5的包，psp版本是04.04.00.02

我们使用其中一个脚用于rs485的片选cs脚，想复用为gpio输出。但是怎么搞都无法其作用，该脚一直为高电平..gpio无法控制它变低，所以485只能发送，接收不了。

代码我放到了/home/tracyone/work/dm8127/Source/ti_tools/ipnc_psp_arago/kernel/arch/arm/mach-omap2/devices.c

中的omap2_init_devices(void)的最后...该函数看起来应该是内核对管脚进行复用设置的顶层函数..所以放在最后应该能保证不被重写

    omap_mux_init_signal("uart0_dcdn.gpio1_2", 0);
    /*omap_writel(0x80, 0x48140924);*/
    error = gpio_request(34, "rs485");
    if (error) {
        printk(KERN_ERR "%s: failed to request GPIO for rs485_cs"
            ": %d\n", __func__, error);
        return;
    }
    gpio_direction_output(34,0); /*默认接收状态*/
    gpio_export(34, true);

然后我有又全局搜索下面这个宏定义所有复用模式，确保没被重写

    _TI814X_MUXENTRY(UART0_DCDN, 0,
            "uart0_dcdn", "uart3_rxd_mux0", NULL, NULL, "spi0_cs3",
            "i2c2_scl_mux0", "mmc1_pow", "gpio1_2", NULL, NULL,
            NULL, NULL),

结果还是无法控制该GPIO，求思路！！






  • 0
    TI__Mastermind 46761 points

    Hi，那你是否有回读过PINCTRL寄存器看这个管脚最终是被配置成什么功能？如果读出来的确不是GPIO的话，还得找找哪里给覆盖了。

  • 0
    Intellectual 658 points

    个人感觉，485读写时，对gpio的高低设置，应该加上一点延时。

  • 0 回复 Eason Wang
    Expert 1160 points

    你好，请问下能在应用层回读这个寄存器的值么？如何？

  • 0 回复 大白他弟
    TI__Mastermind 46761 points

    filesys\opt\ipnc\bin\mem_rdwr.out   可以用help看怎么读

  • 0 回复 Eason Wang
    TI__Genius 12210 points

    能否使用CCS配合以下GEL脚本来确保硬件工作正常？


    #define PRCM_BASE_ADDR 0x48180000

    #define MCBSP_BASE_ADDR 0x47000000

    //GP0[1] Y6 R228

    #define WR_MEM_32(addr, data) *(unsigned int*)(addr) =(unsigned int)(data)
    #define RD_MEM_32(addr) *(unsigned int*)(addr)

    hotmenu GPIO_ClkEnable()
    {

    #define CM_ALWON_GPIO_0_CLKCTRL (PRCM_BASE_ADDR + 0x155C)

    #define CM_ALWON_GPIO_1_CLKCTRL (PRCM_BASE_ADDR + 0x1560)

    WR_MEM_32(CM_ALWON_GPIO_0_CLKCTRL, 0x2); /* Enable GPI0 System and Functional Clock*/

    while(RD_MEM_32(CM_ALWON_GPIO_0_CLKCTRL)!=0x2); /* Poll till Module is functional*/

    WR_MEM_32(CM_ALWON_GPIO_1_CLKCTRL, 0x2); /* Enable GPI1 System and Functional Clock*/

    while(RD_MEM_32(CM_ALWON_GPIO_1_CLKCTRL)!=0x2); /* Poll till Module is functional*/

    GEL_TextOut("\tGPIO 0&1 clock is enalbed successfully !!!\n");

    }

    hotmenu GPIO1_EnableLvcmosPadN_PadPReceiver()
    {

    #define MLBP_SIG_IO_CTRL_FOR_GPb7b8 0x48140E18
    #define MLBP_SIG_IO_CTRL_FOR_GPb9b10 0x48140E1c

    #define MLBP_SIG_IO_CTRL_VAL 0x3F //set 3LSB to enable: 2 lvcmos buffer, padn receiver, padp receiver

    WR_MEM_32(MLBP_SIG_IO_CTRL_FOR_GPb7b8, MLBP_SIG_IO_CTRL_VAL);
    WR_MEM_32(MLBP_SIG_IO_CTRL_FOR_GPb9b10, MLBP_SIG_IO_CTRL_VAL);

    }

    hotmenu GPIO_SelectGPIO_0and1_Pinmux()
    {
    //for GP1
    #define PINCNTL62 0x481408F4
    #define PINCNTL63 0x481408F8
    #define PINCNTL64 0x481408FC
    #define PINCNTL65 0x48140900

    //for GP0
    #define PINCNTL8 0x4814081C

    #define MUX_VAL 0x00040080

    WR_MEM_32(PINCNTL62, MUX_VAL);
    WR_MEM_32(PINCNTL63, MUX_VAL);
    WR_MEM_32(PINCNTL64, MUX_VAL);
    WR_MEM_32(PINCNTL65, MUX_VAL);

    WR_MEM_32(PINCNTL8, 0x00040080);

    }

    hotmenu GPIO_SelectGPIO1_bit7_to_W6_Pinmux()
    {
    //for GP1, check R143
    #define PINCNTL07 0x48140818


    WR_MEM_32(PINCNTL07, 0x00040080);


    }

    hotmenu GPIO1_OutputEnable_High()
    {

    #define GPIO1_OE 0x4804C134
    #define GPIO1_SETDATAOUT 0x4804C194
    #define GPIO1_DATAOUT 0x4804C13C

    WR_MEM_32(GPIO1_OE, 0);
    WR_MEM_32(GPIO1_SETDATAOUT, 0xffffffff);

    }

    hotmenu GPIO1_OutputEnable_Low()
    {

    #define GPIO1_OE 0x4804C134
    #define GPIO1_SETDATAOUT 0x4804C194
    #define GPIO1_DATAOUT 0x4804C13C

    WR_MEM_32(GPIO1_OE, 0);
    WR_MEM_32(GPIO1_DATAOUT, 0);

    }

    hotmenu GPIO0_OutputEnable_High()
    {

    #define GPIO0_OE 0x48032134
    #define GPIO0_SETDATAOUT 0x48032194
    #define GPIO0_DATAOUT 0x4803213C

    WR_MEM_32(GPIO0_OE, 0);
    WR_MEM_32(GPIO0_SETDATAOUT, 0x2);

    }

    hotmenu GPIO0_OutputEnable_Low()
    {

    #define GPIO0_OE 0x48032134
    #define GPIO0_SETDATAOUT 0x48032194
    #define GPIO0_DATAOUT 0x4803213C

    WR_MEM_32(GPIO0_OE, 0);
    WR_MEM_32(GPIO0_DATAOUT, 0);

    }