新路程------uart驱动和tty(3)

来源：互联网发布：windows select epoll 编辑：程序博客网时间：2024/06/07 04:53

这里主要讲讲dev/ttymx0是怎么长出来的，在static int serial_imx_probe(struct platform_device *pdev)我们讲到

这个ret = uart_add_one_port(&imx_reg, &sport->port);是长出dev/ttymx0的关键

那么来看看首先是imx_reg

static struct uart_driver imx_reg = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = DEV_NAME, 这个name是#define DEV_NAME"ttymxc"
.major = SERIAL_IMX_MAJOR,
.minor = MINOR_START,
.nr = ARRAY_SIZE(imx_ports),
.cons = IMX_CONSOLE,
};

第二个参数&sport->port就是ttymx n

在

int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
{

tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);

}

然后是

struct device *tty_register_device(struct tty_driver *driver, unsigned index,   struct device *device){char name[64];dev_t dev = MKDEV(driver->major, driver->minor_start) + index;    char *name1=&name;if (index >= driver->num) {printk(KERN_ERR "Attempt to register invalid tty line number "       " (%d).\n", index);return ERR_PTR(-EINVAL);}if (driver->type == TTY_DRIVER_TYPE_PTY)pty_line_name(driver, index, name);elsetty_line_name(driver, index, name);  //这里组成了ttymxc0     printk("matt==========name1=%s\n",name1);return device_create(tty_class, device, dev, NULL, name);}

最后的device_create就是节点的建立

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