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Diffstat (limited to 'Documentation/DocBook/media/v4l/driver.xml')
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diff --git a/Documentation/DocBook/media/v4l/driver.xml b/Documentation/DocBook/media/v4l/driver.xml deleted file mode 100644 index 7c6638bacedb..000000000000 --- a/Documentation/DocBook/media/v4l/driver.xml +++ /dev/null @@ -1,200 +0,0 @@ - <title>V4L2 Driver Programming</title> - - <!-- This part defines the interface between the "videodev" - module and individual drivers. --> - - <para>to do</para> -<!-- - <para>V4L2 is a two-layer driver system. The top layer is the "videodev" -kernel module. When videodev initializes it registers as character device -with major number 81, and it registers a set of file operations. All V4L2 -drivers are really clients of videodev, which calls V4L2 drivers through -driver method functions. V4L2 drivers are also written as kernel modules. -After probing the hardware they register one or more devices with -videodev.</para> - - <section id="driver-modules"> - <title>Driver Modules</title> - - <para>V4L2 driver modules must have an initialization function which is -called after the module was loaded into kernel, an exit function whis is -called before the module is removed. When the driver is compiled into the -kernel these functions called at system boot and shutdown time.</para> - - <informalexample> - <programlisting> -#include <linux/module.h> - -/* Export information about this module. For details and other useful - macros see <filename>linux/module.h</filename>. */ -MODULE_DESCRIPTION("my - driver for my hardware"); -MODULE_AUTHOR("Your name here"); -MODULE_LICENSE("GPL"); - -static void -my_module_exit (void) -{ - /* Free all resources allocated by my_module_init(). */ -} - -static int -my_module_init (void) -{ - /* Bind the driver to the supported hardware, see - <link linkend="driver-pci"> and - <link linkend="driver-usb"> for examples. */ - - return 0; /* a negative value on error, 0 on success. */ -} - -/* Export module functions. */ -module_init (my_module_init); -module_exit (my_module_exit); -</programlisting> - </informalexample> - - <para>Users can add parameters when kernel modules are inserted:</para> - - <informalexample> - <programlisting> -include <linux/moduleparam.h> - -static int my_option = 123; -static int my_option_array[47]; - -/* Export the symbol, an int, with access permissions 0664. - See <filename>linux/moduleparam.h</filename> for other types. */ -module_param (my_option, int, 0644); -module_param_array (my_option_array, int, NULL, 0644); - -MODULE_PARM_DESC (my_option, "Does magic things, default 123"); -</programlisting> - </informalexample> - - <para>One parameter should be supported by all V4L2 drivers, the minor -number of the device it will register. Purpose is to predictably link V4L2 -drivers to device nodes if more than one video device is installed. Use the -name of the device node followed by a "_nr" suffix, for example "video_nr" -for <filename>/dev/video</filename>.</para> - - <informalexample> - <programlisting> -/* Minor number of the device, -1 to allocate the first unused. */ -static int video_nr = -1; - -module_param (video_nr, int, 0444); -</programlisting> - </informalexample> - </section> - - <section id="driver-pci"> - <title>PCI Devices</title> - - <para>PCI devices are initialized like this:</para> - - <informalexample> - <programlisting> -typedef struct { - /* State of one physical device. */ -} my_device; - -static int -my_resume (struct pci_dev * pci_dev) -{ - /* Restore the suspended device to working state. */ -} - -static int -my_suspend (struct pci_dev * pci_dev, - pm_message_t state) -{ - /* This function is called before the system goes to sleep. - Stop all DMAs and disable interrupts, then put the device - into a low power state. For details see the kernel - sources under <filename>Documentation/power</filename>. */ - - return 0; /* a negative value on error, 0 on success. */ -} - -static void -my_remove (struct pci_dev * pci_dev) -{ - my_device *my = pci_get_drvdata (pci_dev); - - /* Describe me. */ -} - -static int -my_probe (struct pci_dev * pci_dev, - const struct pci_device_id * pci_id) -{ - my_device *my; - - /* Describe me. */ - - /* You can allocate per-device data here and store a pointer - to it in the pci_dev structure. */ - my = ...; - pci_set_drvdata (pci_dev, my); - - return 0; /* a negative value on error, 0 on success. */ -} - -/* A list of supported PCI devices. */ -static struct pci_device_id -my_pci_device_ids [] = { - { PCI_VENDOR_ID_FOO, PCI_DEVICE_ID_BAR, - PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 }, - { 0 } /* end of list */ -}; - -/* Load our module if supported PCI devices are installed. */ -MODULE_DEVICE_TABLE (pci, my_pci_device_ids); - -static struct pci_driver -my_pci_driver = { - .name = "my", - .id_table = my_pci_device_ids, - - .probe = my_probe, - .remove = my_remove, - - /* Power management functions. */ - .suspend = my_suspend, - .resume = my_resume, -}; - -static void -my_module_exit (void) -{ - pci_unregister_driver (&my_pci_driver); -} - -static int -my_module_init (void) -{ - return pci_register_driver (&my_pci_driver); -} -</programlisting> - </informalexample> - </section> - - <section id="driver-usb"> - <title>USB Devices</title> - <para>to do</para> - </section> - <section id="driver-registering"> - <title>Registering V4L2 Drivers</title> - - <para>After a V4L2 driver probed the hardware it registers one or more -devices with the videodev module.</para> - </section> - <section id="driver-file-ops"> - <title>File Operations</title> - <para>to do</para> - </section> - <section id="driver-internal-api"> - <title>Internal API</title> - <para>to do</para> - </section> ---> |