新路程------uart驱动和tty(3)

  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);
else
tty_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