linux uart驱动——uart platfrom 注册（三）

一：注册platform device

注册一个platfrom device一般需要初始化两个内容，设备占用的资源resource和设备私有数据dev.platfrom_data。设备的resource占用的资源主要包含两个方面：IO内存和IRQ资源信息，有时也包含DMA。

resource结构：

struct resource {
    resource_size_t start;//定义资源的起始地址
    resource_size_t end;//定义资源的结束地址
    const char *name;//定义资源的名称
    unsigned long flags;//定义资源的类型，比如MEM，IO，IRQ，DMA类型
    struct resource *parent, *sibling, *child;//资源链表指针
};

笔者当前的君正board有三个串口：

#ifdef CONFIG_SERIAL_JZ47XX_UART0
/* UART ( uart controller) */
static struct resource jz_uart0_resources[] = {
    [0] = {
        .start          = UART0_IOBASE,
        .end            = UART0_IOBASE + 0x1000 - 1,
        .flags          = IORESOURCE_MEM,
    },
    [1] = {
        .start          = IRQ_UART0,
        .end            = IRQ_UART0,
        .flags          = IORESOURCE_IRQ,
    },
#ifdef CONFIG_SERIAL_JZ47XX_UART0_DMA
    [2] = {
        .start          = JZDMA_REQ_UART0,
        .flags          = IORESOURCE_DMA,
    },
#endif
};

struct platform_device jz_uart0_device = {
    .name = "jz-uart",
    .id = 0,
    .num_resources  = ARRAY_SIZE(jz_uart0_resources),
    .resource       = jz_uart0_resources,
};
#endif
#ifdef CONFIG_SERIAL_JZ47XX_UART1
static struct resource jz_uart1_resources[] = {
    [0] = {
        .start          = UART1_IOBASE,
        .end            = UART1_IOBASE + 0x1000 - 1,
        .flags          = IORESOURCE_MEM,
    },
    [1] = {
        .start          = IRQ_UART1,
        .end            = IRQ_UART1,
        .flags          = IORESOURCE_IRQ,
    },
#ifdef CONFIG_SERIAL_JZ47XX_UART1_DMA
    [2] = {
        .start          = JZDMA_REQ_UART1,
        .flags          = IORESOURCE_DMA,
    },
#endif
};
struct platform_device jz_uart1_device = {
    .name = "jz-uart",
    .id = 1,
    .num_resources  = ARRAY_SIZE(jz_uart1_resources),
    .resource       = jz_uart1_resources,
};
#endif
#ifdef CONFIG_SERIAL_JZ47XX_UART2
static struct resource jz_uart2_resources[] = {
    [0] = {
        .start          = UART2_IOBASE,
        .end            = UART2_IOBASE + 0x1000 - 1,
        .flags          = IORESOURCE_MEM,
    },
    [1] = {
        .start          = IRQ_UART2,
        .end            = IRQ_UART2,
        .flags          = IORESOURCE_IRQ,
    },
#ifdef CONFIG_SERIAL_JZ47XX_UART2_DMA
    [2] = {
        .start          = JZDMA_REQ_UART2,
        .flags          = IORESOURCE_DMA,
    },
#endif
};

struct platform_device jz_uart2_device = {
    .name = "jz-uart",
    .id = 2,
    .num_resources  = ARRAY_SIZE(jz_uart2_resources),
    .resource       = jz_uart2_resources,
};
#endif

platform_device_register(&jz_uartXX_device);

注册成功后：（多个device）

ls /sys/bus/platform/devices/
jz-uart.0/  jz-uart.2/

二：注册platfrom driver

/* serial platfrom driver */
static struct platform_driver serial_jz47xx_driver = {
    .probe          = serial_jz47xx_probe,
    .remove         = serial_jz47xx_remove,

    .driver        = {
        .name    = "jz-uart",
        .owner    = THIS_MODULE,
#ifdef CONFIG_PM
        .pm    = &serial_jz47xx_pm_ops,
#endif
    },
};

int __init serial_jz47xx_init(void)
{
    int ret;
    /* 功能：uart_register_driver用于将串口驱动uart_driver注册到内核(串口核心层)中，
                通常在模块初始化函数调用该函数。
      * 参数 drv：要注册的uart_driver
      * 返回值：  成功，返回0；否则返回错误码
     */
    ret = uart_register_driver(&serial_jz47xx_reg);
    if (ret != 0)
        return ret;

    /* 注册serial platfrom驱动 */
    ret = platform_driver_register(&serial_jz47xx_driver);
    if (ret != 0)
        uart_unregister_driver(&serial_jz47xx_reg);

    return ret;
}

void __exit serial_jz47xx_exit(void)
{
    platform_driver_unregister(&serial_jz47xx_driver);
    uart_unregister_driver(&serial_jz47xx_reg);
}


#ifdef CONFIG_EARLY_INIT_RUN
rootfs_initcall(serial_jz47xx_init);/*先于module注册*/

#else
module_init(serial_jz47xx_init);

#endif

module_exit(serial_jz47xx_exit);

MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:jz47xx-uart");

注册成功后：（一个driver对应多个device）

ls /sys/bus/platform/drivers/jz-uart/
bind       jz-uart.0  jz-uart.2  uevent     unbind