struct platform_driver 结构体的阅读笔记（3.0.35）

struct platform_driver {/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */ int (*probe)(struct platform_device *); int (*remove)(struct platform_device *); void (*shutdown)(struct platform_device *); int (*suspend)(struct platform_device *, pm_message_t state);/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */ int (*resume)(struct platform_device *); struct device_driver driver;};

这个结构体在platfoem_driver.h中定义。字面翻译为平台驱动，里面包含了探测，删除，关闭，挂起，重启回调函数，同时包含一个设备驱动结构体。

static int serial_imx_probe(struct platform_device *pdev){struct imx_port *sport;struct imxuart_platform_data *pdata;void __iomem *base;int ret = 0;struct resource *res;sport = kzalloc(sizeof(*sport), GFP_KERNEL);//申请内存，底层是callocif (!sport)return -ENOMEM;res = platform_get_resource(pdev, IORESOURCE_MEM, 0);//第一条注释if (!res) {ret = -ENODEV;goto free;}base = ioremap(res->start, PAGE_SIZE);//ioremap将一个IO地址空间映射到内核的虚拟地址空间上去，便于访问。（这是百度百科参考的CSDN的结果，呃呃）具体不深入if (!base) {ret = -ENOMEM;goto free;}sport->port.dev = &pdev->dev;//下面都是对sport这个结构体的赋值sport->port.mapbase = res->start;sport->port.membase = base;sport->port.type = PORT_IMX,sport->port.iotype = UPIO_MEM;sport->port.irq = platform_get_irq(pdev, 0);sport->rxirq = platform_get_irq(pdev, 0);sport->txirq = platform_get_irq(pdev, 1);sport->rtsirq = platform_get_irq(pdev, 2);sport->port.fifosize = 32;sport->port.ops = &imx_pops;sport->port.flags = UPF_BOOT_AUTOCONF;sport->port.line = pdev->id;init_timer(&sport->timer);sport->timer.function = imx_timeout;sport->timer.data     = (unsigned long)sport;sport->clk = clk_get(&pdev->dev, "uart");if (IS_ERR(sport->clk)) {ret = PTR_ERR(sport->clk);goto unmap;}if (uart_at_24)clk_set_parent(sport->clk, clk_get(NULL, "osc"));clk_enable(sport->clk);sport->port.uartclk = clk_get_rate(sport->clk);imx_ports[pdev->id] = sport;pdata = pdev->dev.platform_data;if (pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))sport->have_rtscts = 1;if (pdata && (pdata->flags & IMXUART_USE_DCEDTE))sport->use_dcedte = 1;if (pdata && (pdata->flags & IMXUART_SDMA))sport->enable_dma = 1;#ifdef CONFIG_IRDAif (pdata && (pdata->flags & IMXUART_IRDA))sport->use_irda = 1;#endifif (pdata && pdata->init) {ret = pdata->init(pdev);if (ret)goto clkput;}ret = uart_add_one_port(&imx_reg, &sport->port);if (ret)goto deinit;platform_set_drvdata(pdev, &sport->port);clk_disable(sport->clk);return 0;deinit:if (pdata && pdata->exit)pdata->exit(pdev);clkput:clk_put(sport->clk);clk_disable(sport->clk);unmap:iounmap(sport->port.membase);free:kfree(sport);return ret;}

这是imx串口的probe回调函数，看看这个函数做了什么：

1.

platform_get_resource(pdev, IORESOURCE_MEM, 0)看看这个函数干了什么，字面上是获得资源，跟踪之后（略）可以看到是通过传入的platdorm_device返回resource结构体，将resource结构体摘录如下：struct resource {    resource_size_t start;    resource_size_t end;    const char *name;    unsigned long flags;    struct resource *parent, *sibling, *child;};

可以看到这个结构体包含一个起始地址，一个结束地址，一个name一个flages以及一个父节点，兄弟节点，子节点。说明这个资源结构体应该是通过树的形式管理的。