PowerQUICC Processors中的主题 Re: Could some one elaborate irq_create_mapping, irq_find_mapping, to use request_irq https://community.nxp.com/t5/PowerQUICC-Processors/Could-some-one-elaborate-irq-create-mapping-irq-find-mapping-to/m-p/376356#M955 <HTML><HEAD></HEAD><BODY><P>Linux IRQ numbers, as used by request_irq() and similar functions, are arbitrary software tokens rather than hardware IRQ numbers.&nbsp; To obtain such a token (called a virtual IRQ number, or virq) you need to create a mapping.&nbsp; The most common way to do that is to either use irq_of_parse_and_map(), or get the virq from a bus-specific structure (e.g. struct pci_dev or struct platform_device).</P><P></P><P>irq_create_mapping() is the low-level function used by the above methods of translation.&nbsp; It's possible to use it directly, but you normally shouldn't have to.&nbsp; If you find yourself wanting to use it, it probably means that you have hardware that should be described in the device tree but isn't.</P><P></P><P>irq_find_mapping() is one method used by interrupt controller drivers to turn a hardware interrupt number into a virq using an existing mapping.&nbsp; If you're not writing an interrupt controller driver or something similar, you don't need this.</P></BODY></HTML> Wed, 08 Oct 2014 16:46:55 GMT scottwood 2014-10-08T16:46:55Z Could some one elaborate irq_create_mapping, irq_find_mapping, to use request_irq https://community.nxp.com/t5/PowerQUICC-Processors/Could-some-one-elaborate-irq-create-mapping-irq-find-mapping-to/m-p/376355#M954 <HTML><HEAD></HEAD><BODY><P>Could some one elaborate irq_create_mapping, irq_find_mapping, to use request_irq </P><P></P><P>Thanks</P><P>Rama</P></BODY></HTML> Wed, 08 Oct 2014 13:45:12 GMT https://community.nxp.com/t5/PowerQUICC-Processors/Could-some-one-elaborate-irq-create-mapping-irq-find-mapping-to/m-p/376355#M954 ramakrishnakatt 2014-10-08T13:45:12Z Re: Could some one elaborate irq_create_mapping, irq_find_mapping, to use request_irq https://community.nxp.com/t5/PowerQUICC-Processors/Could-some-one-elaborate-irq-create-mapping-irq-find-mapping-to/m-p/376356#M955 <HTML><HEAD></HEAD><BODY><P>Linux IRQ numbers, as used by request_irq() and similar functions, are arbitrary software tokens rather than hardware IRQ numbers.&nbsp; To obtain such a token (called a virtual IRQ number, or virq) you need to create a mapping.&nbsp; The most common way to do that is to either use irq_of_parse_and_map(), or get the virq from a bus-specific structure (e.g. struct pci_dev or struct platform_device).</P><P></P><P>irq_create_mapping() is the low-level function used by the above methods of translation.&nbsp; It's possible to use it directly, but you normally shouldn't have to.&nbsp; If you find yourself wanting to use it, it probably means that you have hardware that should be described in the device tree but isn't.</P><P></P><P>irq_find_mapping() is one method used by interrupt controller drivers to turn a hardware interrupt number into a virq using an existing mapping.&nbsp; If you're not writing an interrupt controller driver or something similar, you don't need this.</P></BODY></HTML> Wed, 08 Oct 2014 16:46:55 GMT https://community.nxp.com/t5/PowerQUICC-Processors/Could-some-one-elaborate-irq-create-mapping-irq-find-mapping-to/m-p/376356#M955 scottwood 2014-10-08T16:46:55Z