On Mon, Nov 26, 2012 at 2:02 PM, Jinqiang Zeng <[email protected]> wrote: > > first creat a device class,then register a device to the kernel. using the > following functions: > struct class *class_create(struct module *owner, char *name)； > struct class_device *class_device_create(struct class *cls, > struct class_device *parent, > dev_t devt, > struct device *device, char *fmt, ...) > > > 2012/11/26 Manavendra Nath Manav <[email protected]> >> >> >> On Sat, Nov 24, 2012 at 2:20 PM, Manavendra Nath Manav >> <[email protected]> wrote: >>> >>> Hi RK >>> >>> On Sat, Nov 24, 2012 at 2:03 PM, Manavendra Nath Manav >>> <[email protected]> wrote: >>>> >>>> I have written a simple UART serial driver in embedded Linux running >>>> busybox with mdev rules. I have provided .dev_name as "ttyC2C" in my >>>> driver code. >>>> >>>> static struct uart_driver serial_omap_reg = { >>>> .owner = THIS_MODULE, >>>> .driver_name = "Omap-C2C-Serial", >>>> .dev_name = "ttyC2C", >>>> .nr = OMAP_MAX_HSUART_PORTS, >>>> .cons = NULL, >>>> }; >>>> >>>> However the node is getting created in >>>> >>>> ./sys/devices/platform/omap_c2c_uart.0/tty/ttyC2C0 >>>> ./sys/class/tty/ttyC2C0 >>>> >>>> / # ls -l ./sys/class/tty/ttyC2C0 >>>> lrwxrwxrwx 1 root 0 0 Jan 1 00:14 >>>> ./sys/class/tty/ttyC2C0 -> >>>> ../../devices/platform/omap_c2c_uart.0/tty/ttyC2C0 >>>> >>>> / # ls -l ./sys/devices/platform/omap_c2c_uart.0/tty/ttyC2C0 >>>> -r--r--r-- 1 root 0 4096 Jan 1 00:14 dev >>>> lrwxrwxrwx 1 root 0 0 Jan 1 00:14 device -> >>>> ../../../omap_c2c_uart.0 >>>> drwxr-xr-x 2 root 0 0 Jan 1 00:14 power >>>> lrwxrwxrwx 1 root 0 0 Jan 1 00:14 subsystem -> >>>> ../../../../../class/tty >>>> -rw-r--r-- 1 root 0 4096 Jan 1 00:14 uevent >>>> / # >>>> >>>> The mdev rules for tty are: >>>> >>>> tty 0:5 0666 >>>> tty.* 0:0 0620 >>>> >>>> How to get device node as /dev/ttyC2C ? >>>> >>>> -- >>>> Manavendra Nath Manav >>> >>> >>> can you help me on following issue? >>> >>> -- >>> Manavendra Nath Manav >> >> >> In "Essential Linux Device Drivers" book, it says that that the driver name >> in "struct platform_driver" and "struct uart_driver" should be same. I >> modified the code according but still /dev/ttyC2C node is not being >> populated. >> >> -- >> Manavendra Nath Manav
When i add .major and .minor to the struct uart_driver and create the device node manually using "mknod" then the driver works fine. Why the kernel (3.4.0) is not able to create it automatically? -- Manavendra Nath Manav _______________________________________________ Kernelnewbies mailing list [email protected] http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
