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Diffstat (limited to 'Documentation/driver-api/uio-howto.rst')
| -rw-r--r-- | Documentation/driver-api/uio-howto.rst | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/Documentation/driver-api/uio-howto.rst b/Documentation/driver-api/uio-howto.rst index 25f50eace28b..907ffa3b38f5 100644 --- a/Documentation/driver-api/uio-howto.rst +++ b/Documentation/driver-api/uio-howto.rst @@ -274,10 +274,10 @@ fields of ``struct uio_mem``: region, it will show up in the corresponding sysfs node. - ``int memtype``: Required if the mapping is used. Set this to - ``UIO_MEM_PHYS`` if you you have physical memory on your card to be + ``UIO_MEM_PHYS`` if you have physical memory on your card to be mapped. Use ``UIO_MEM_LOGICAL`` for logical memory (e.g. allocated - with :c:func:`kmalloc()`). There's also ``UIO_MEM_VIRTUAL`` for - virtual memory. + with :c:func:`__get_free_pages()` but not kmalloc()). There's also + ``UIO_MEM_VIRTUAL`` for virtual memory. - ``phys_addr_t addr``: Required if the mapping is used. Fill in the address of your memory block. This address is the one that appears in @@ -408,6 +408,13 @@ handler code. You also do not need to know anything about the chip's internal registers to create the kernel part of the driver. All you need to know is the irq number of the pin the chip is connected to. +When used in a device-tree enabled system, the driver needs to be +probed with the ``"of_id"`` module parameter set to the ``"compatible"`` +string of the node the driver is supposed to handle. By default, the +node's name (without the unit address) is exposed as name for the +UIO device in userspace. To set a custom name, a property named +``"linux,uio-name"`` may be specified in the DT node. + Using uio_dmem_genirq for platform devices ------------------------------------------ |