[OHOS - STM32MP157] 1 GPIO驱动分析原创精华

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发布于 2022-2-28 13:27

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[OHOS - STM32MP157] 1 GPIO驱动分析

1 . STM32MP157GPIO寄存器

【参考资料】dm00327659-stm32mp157-advanced-armbased-32bit-mpus-stmicroelectronics.pdf

寄存器组地址

【P159 Memory map and register boundary addresses Table 9. Register boundary addresses】

以PA0为例：
[OHOS - STM32MP157] 1 GPIO驱动分析-鸿蒙开发者社区
由上表可知，GPIOA基地址为0x50002000，记住备用。

【以输出模式为例】查看芯片GPIO使用方法：

【P1064 I/O pin alternate function multiplexer and mapping 】: 找到如下描述：

[OHOS - STM32MP157] 1 GPIO驱动分析-鸿蒙开发者社区

【配置PA0为高速推挽上拉输出高电平模式】

下面看GPIO寄存器组：

【P1072 GPIO registers】

【GPIO port mode register (GPIOx_MODER) 】端口模式配置寄存器

[OHOS - STM32MP157] 1 GPIO驱动分析-鸿蒙开发者社区

由上图可知，该寄存器每两位控制一个IO口，如PA0配置为输出模式，即将该寄存器MODER0[1:0]位配置为01即可，该寄存器地址为GPIOA基地址 + 寄存器偏移地址，由上面得到的GPIOA基地址为0x50002000，由上图得到端口模式配置寄存器偏移地址为0x00，故我们最后需要的操作就是将0x50002000+0x00地址的低两位设置为01（输出）即可。

【GPIO port output type register (GPIOx_OTYPER) 】输出类型配置寄存器

配置详情同上，最后需要的操作就是将0x50002000+0x04地址的低一位设置为0（推挽输出）。

【GPIO port pull-up/pull-down register (GPIOx_PUPDR) 】端口上下拉配置寄存器

配置详情同上，最后需要的操作就是将0x50002000+0x0C地址的低两位设置为01（上拉）。

【GPIO port output data register (GPIOx_ODR) 】端口输出数据配置寄存器

配置详情同上，最后需要的操作就是将0x50002000+0x14地址的低一位设置为1（高电平）。

自此，芯片数据手册分析完毕，下面是openHarmony与具体soc平台GPIO的相关开发介绍。

2 .openHarmony驱动加载

驱动框架详情参考官方文档 | OpenHarmony

驱动加载入口

/* HdfDriverEntry definition */
struct HdfDriverEntry g_GpioDriverEntry = {
    .moduleVersion = 1,
    .moduleName = "HDF_PLATFORM_GPIO",
    .Bind = GpioDriverBind,
    .Init = GpioDriverInit,
    .Release = GpioDriverRelease,
};

/* Init HdfDriverEntry */
HDF_INIT(g_GpioDriverEntry);

驱动加载时会执行Bind方法和Init方法，详情参考官方文档，本文只做GPIO分析，不做驱动框架层面分析。

bind方法，GPIO驱动里面不做具体操作：

static int32_t GpioDriverBind(struct HdfDeviceObject *device)
{   
    (void)device;
    return HDF_SUCCESS;
}

Init方法,获取hcs文件具体配置信息，根据该信息初始化硬件驱动：

device_gpio :: device {
                device0 :: deviceNode {
                    policy = 0;
                    priority = 10;
                    permission = 0644;
                    moduleName = "HDF_PLATFORM_GPIO";
                    serviceName = "HDF_PLATFORM_GPIO";
                    deviceMatchAttr = "st_stm32mp157_gpio";
                }
            }
            gpio_config {
            controller_0x50002000 {
                match_attr = "st_stm32mp157_gpio";
                groupNum = 11;
                bitNum = 16;
                gpioRegBase = 0x50002000;
                gpioRegStep = 0x1000;
                irqRegBase = 0x5000D000;
                irqRegStep = 0x400;
            }
        }

static int32_t GpioDriverInit(struct HdfDeviceObject *device)
{
   
    int32_t ret;
    struct Stm32GpioCntlr *stm32gpio = &g_Stm32GpioCntlr;

    HDF_LOGD("%s: Enter", __func__);
    if (device == NULL || device->property == NULL) {
        HDF_LOGE("%s: device or property NULL!", __func__);
        return HDF_ERR_INVALID_OBJECT;
    }
    //获取属性数据
    ret = Stm32GpioReadDrs(stm32gpio, device->property); //读取hcs配置属性，
    /***************************分析时复制到此***************************************
    补充插入GPIO描述结构
    struct Stm32GpioCntlr {
        struct GpioCntlr cntlr; 	// HDF驱动框架父对象
        volatile unsigned char *regBase;	//GPIO寄存器基地址 ： 为映射后的虚拟地址
        EXTI_TypeDef *exitBase;
        uint32_t gpioPhyBase;
        uint32_t gpioRegStep;
        uint32_t irqPhyBase;
        uint32_t iqrRegStep;
        uint16_t groupNum;
        uint16_t bitNum;
        struct GpioGroup *groups;
	}
    ******函数调用传入设备描述对象结构体以及设备节点属性，该函数实现数据解析，类似设备树解析
        static int32_t Stm32GpioReadDrs(struct Stm32GpioCntlr *stm32gpio, const struct DeviceResourceNode *node)
    {
        int32_t ret;
        struct DeviceResourceIface *drsOps = NULL;

        drsOps = DeviceResourceGetIfaceInstance(HDF_CONFIG_SOURCE);
        if (drsOps == NULL || drsOps->GetUint32 == NULL) {
            HDF_LOGE("%s: invalid drs ops fail!", __func__);
            return HDF_FAILURE;
        }

        ret = drsOps->GetUint32(node, "gpioRegBase", &stm32gpio->gpioPhyBase, 0);
        //获取GPIO寄存器基地址0x50002000，该地址是基于上面数据手册得到的GPIOA的寄存器基地址（实际物理地址）
        if (ret != HDF_SUCCESS) {
            HDF_LOGE("%s: read regBase fail!", __func__);
            return ret;
        }

        ret = drsOps->GetUint32(node, "gpioRegStep", &stm32gpio->gpioRegStep, 0);
        //由于STM32MP157GPIO组并非连续地址，查阅手册后的到GPIO端口之间地址间距为0x1000
        if (ret != HDF_SUCCESS) {
            HDF_LOGE("%s: read gpioRegStep fail!", __func__);
            return ret;
        }

        ret = drsOps->GetUint16(node, "groupNum", &stm32gpio->groupNum, 0);
        //获取GPIO分组数，STM32MP157分组为A,B,C,D,E,F,G,H,I,J,Z共11组
        if (ret != HDF_SUCCESS) {
            HDF_LOGE("%s: read groupNum fail!", __func__);
            return ret;
        }

        ret = drsOps->GetUint16(node, "bitNum", &stm32gpio->bitNum, 0);
        //获取每组GPIO数量，STM32MP157一组IO数量为16
        if (ret != HDF_SUCCESS) {
            HDF_LOGE("%s: read bitNum fail!", __func__);
            return ret;
        }

        ret = drsOps->GetUint32(node, "irqRegBase", &stm32gpio->irqPhyBase, 0);
        //获取中断寄存器基地址
        if (ret != HDF_SUCCESS) {
            HDF_LOGE("%s: read regBase fail!", __func__);
            return ret;
        }

        ret = drsOps->GetUint32(node, "irqRegStep", &stm32gpio->iqrRegStep, 0);
        //获取中断寄存器地址间距
        if (ret != HDF_SUCCESS) {
            HDF_LOGE("%s: read gpioRegStep fail!", __func__);
            return ret;
        }
        return HDF_SUCCESS;
    }
    ***********************************************************/
    if (ret != HDF_SUCCESS) {
        HDF_LOGE("%s: get gpio device resource fail:%d", __func__, ret);
        return ret;
    }

    if (stm32gpio->groupNum > GROUP_MAX || stm32gpio->groupNum <= 0 || stm32gpio->bitNum > BIT_MAX ||
        stm32gpio->bitNum <= 0) {
        HDF_LOGE("%s: invalid groupNum:%u or bitNum:%u", __func__, stm32gpio->groupNum,
                 stm32gpio->bitNum);
        return HDF_ERR_INVALID_PARAM;
    }
    //寄存器地址映射，MMU操作
    stm32gpio->regBase = OsalIoRemap(stm32gpio->gpioPhyBase, stm32gpio->groupNum * stm32gpio->gpioRegStep);
    if (stm32gpio->regBase == NULL) {
        HDF_LOGE("%s: err remap phy:0x%x", __func__, stm32gpio->gpioPhyBase);
        return HDF_ERR_IO;
    }
    /* OsalIoRemap: remap registers */
    stm32gpio->exitBase = OsalIoRemap(stm32gpio->irqPhyBase, stm32gpio->iqrRegStep);
    if (stm32gpio->exitBase == NULL) {
        dprintf("%s: OsalIoRemap fail!", __func__);
        return -1;
    }

    ret = InitGpioCntlrMem(stm32gpio);
    if (ret != HDF_SUCCESS) {
        HDF_LOGE("%s: err init cntlr mem:%d", __func__, ret);
        OsalIoUnmap((void *)stm32gpio->regBase);
        stm32gpio->regBase = NULL;
        return ret;
    }
    stm32gpio->cntlr.count = stm32gpio->groupNum * stm32gpio->bitNum;
    stm32gpio->cntlr.priv = (void *)device->property;
    stm32gpio->cntlr.device = device;
    stm32gpio->cntlr.ops = &g_GpioMethod;
    ret = GpioCntlrAdd(&stm32gpio->cntlr);
    if (ret != HDF_SUCCESS) {
        HDF_LOGE("%s: err add controller: %d", __func__, ret);
        return ret;
    }
    HDF_LOGE("%s: dev service:%s init success!", __func__, HdfDeviceGetServiceName(device));
    return ret;
}

上述为openHarmony初始化GPIO的方法简单介绍，详细情况请仔细阅读源码，自此，OpenHarmony已经得到STM32MP157芯片的GPIO外设基本信息，我们继续往下分析。

3 .openHarmony驱动GPIO

参考官方文档：GPIO | OpenHarmony

【openHarmony对外提供的GPIO驱动函数】

struct GpioMethod {
  int32_t (*request)(struct GpioCntlr *cntlr, uint16_t local);// 【可选】
  int32_t (*release)(struct GpioCntlr *cntlr, uint16_t local);// 【可选】
  int32_t (*write)(struct GpioCntlr *cntlr, uint16_t local, uint16_t val);
  int32_t (*read)(struct GpioCntlr *cntlr, uint16_t local, uint16_t *val);
  int32_t (*setDir)(struct GpioCntlr *cntlr, uint16_t local, uint16_t dir);
  int32_t (*getDir)(struct GpioCntlr *cntlr, uint16_t local, uint16_t *dir);
  int32_t (*toIrq)(struct GpioCntlr *cntlr, uint16_t local, uint16_t *irq);// 【可选】
  int32_t (*setIrq)(struct GpioCntlr *cntlr, uint16_t local, uint16_t mode, GpioIrqFunc func, void *arg);
  int32_t (*unsetIrq)(struct GpioCntlr *cntlr, uint16_t local);
  int32_t (*enableIrq)(struct GpioCntlr *cntlr, uint16_t local);
  int32_t (*disableIrq)(struct GpioCntlr *cntlr, uint16_t local);
}

STM32MP157驱动函数实例化：

struct GpioMethod g_GpioMethod = {
    .request = NULL,
    .release = NULL,
    .write = Stm32Mp157GpioWrite,
    .read = Stm32Mp157GpioRead,
    .setDir = Stm32Mp157GpioSetDir,
    .getDir = Stm32Mp157GpioGetDir,
    .toIrq = NULL,
    .setIrq = Stm32Mp157GpioSetIrq,
    .unsetIrq = Stm32Mp157GpioUnsetIrq,
    .enableIrq = Stm32Mp157GpioEnableIrq,
    .disableIrq = Stm32Mp157GpioDisableIrq,
};

【Stm32Mp157GpioSetDir】设置GPIO引脚反向

函数名	入参	出参	返回值	功能
Stm32Mp157GpioSetDir	cntlr：结构体指针，核心层GPIO控制器;local：uint16_t，GPIO端口标识号 ;dir：uint16_t，管脚方向传入值;	无	HDF_STATUS相关状态	设置GPIO引脚输入/输出方向

static int32_t Stm32Mp157GpioSetDir(struct GpioCntlr *cntlr, uint16_t gpio, uint16_t dir)
{
    int32_t ret;
    uint32_t irqSave;
    unsigned int val;
    volatile unsigned char *addr = NULL;

    unsigned int bitNum = Stm32ToBitNum(gpio);  //将GPIO端口号转换为位号 如 0 = PA0 -> 0
    struct GpioGroup *group = NULL;

    ret = Stm32GetGroupByGpioNum(cntlr, gpio, &group); //将GPIO端口号转换为组号 如 1 = PA1 -> 0
    if (ret != HDF_SUCCESS) {
        HDF_LOGE("Stm32GetGroupByGpioNum failed\n");
        return ret;
    }

    if (OsalSpinLockIrqSave(&group->lock, &irqSave) != HDF_SUCCESS) {
        HDF_LOGE("OsalSpinLockIrqSave failed\n");
        return HDF_ERR_DEVICE_BUSY;
    }
    /**
    ************************************补充宏定义说明**********************************
    #define STM32MP15X_GPIO_DIR(base)        ((base) + 0x00)  基地址+偏移地址
    #define STM32MP15X_GPIO_DATA(base)       ((base) + 0x18)
    #define STM32MP15X_GPIO_IDR(base)        ((base) + 0x10)
    *****/
    addr = STM32MP15X_GPIO_DIR(group->regBase);	 //获取GPIO寄存器地址，此处为虚拟地址
    val = OSAL_READL(addr);		//读取原来寄存器的值
    if (dir == GPIO_DIR_IN) {
        val &= ~(0X3 << (bitNum*2)); /* bit0:1 清零 */  // 位操作
    } else if (dir == GPIO_DIR_OUT) {
        val &= ~(0X3 << (bitNum*2)); /* bit0:1 清零 */
        val |= (0X1 << (bitNum*2)); /* bit0:1 设置 01 */
    }
    OSAL_WRITEL(val, addr); // 将运算后的值写入寄存器，配置完成
    (void)OsalSpinUnlockIrqRestore(&group->lock, &irqSave);
    return HDF_SUCCESS;
}

【Stm32Mp157GpioWrite】设置GPIO输出电平

函数名	入参	出参	返回值	功能
Stm32Mp157GpioWrite	cntlr：结构体指针，核心层GPIO控制器;local：uint16_t，GPIO端口标识号 ;val：uint16_t，电平传入值;	无	HDF_STATUS相关状态	GPIO引脚写入电平值

static int32_t Stm32Mp157GpioWrite(struct GpioCntlr *cntlr, uint16_t gpio, uint16_t val)
{
    int32_t ret;
    uint32_t irqSave;
    unsigned int valCur;
    unsigned int bitNum = Stm32ToBitNum(gpio);
    volatile unsigned char *addr = NULL;
    struct GpioGroup *group = NULL;

    ret = Stm32GetGroupByGpioNum(cntlr, gpio, &group);
    if (ret != HDF_SUCCESS) {
        return ret;
    }
    if (OsalSpinLockIrqSave(&group->lock, &irqSave) != HDF_SUCCESS) {
        return HDF_ERR_DEVICE_BUSY;
    }
    /**
    ************************************补充宏定义说明**********************************
    #define STM32MP15X_GPIO_DIR(base)        ((base) + 0x00)  基地址+偏移地址
    #define STM32MP15X_GPIO_DATA(base)       ((base) + 0x18)  基地址+偏移地址
    #define STM32MP15X_GPIO_IDR(base)        ((base) + 0x10)
    *****/
    addr = STM32MP15X_GPIO_DATA(group->regBase);//获取输出数据寄存器地址
    valCur = OSAL_READL(addr);
    if (val == GPIO_VAL_LOW) {
        valCur &= ~(0x1 << bitNum);
        valCur |= (0x1 << (bitNum+16));
    } else {
        valCur |= (0x1 << bitNum);
    }
    OSAL_WRITEL(valCur, addr);
    (void)OsalSpinUnlockIrqRestore(&group->lock, &irqSave);

    return HDF_SUCCESS;
}

其他函数请自行阅读源码。

device/st/drivers/gpio · 小熊派开源社区/BearPi-HM_Micro_small - 码云 - 开源中国 (gitee.com)

自此，openHarmony操作硬件寄存器的基本流程已经介绍完毕，供阅读参考。