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Diffstat (limited to 'Documentation/DocBook/uio-howto.tmpl')
| -rw-r--r-- | Documentation/DocBook/uio-howto.tmpl | 69 |
1 files changed, 65 insertions, 4 deletions
diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl index b4665b9c40b..bbe9c1fd5ce 100644 --- a/Documentation/DocBook/uio-howto.tmpl +++ b/Documentation/DocBook/uio-howto.tmpl @@ -521,6 +521,11 @@ Here's a description of the fields of <varname>struct uio_mem</varname>: <itemizedlist> <listitem><para> +<varname>const char *name</varname>: Optional. Set this to help identify +the memory region, it will show up in the corresponding sysfs node. +</para></listitem> + +<listitem><para> <varname>int memtype</varname>: Required if the mapping is used. Set this to <varname>UIO_MEM_PHYS</varname> if you you have physical memory on your card to be mapped. Use <varname>UIO_MEM_LOGICAL</varname> for logical @@ -529,7 +534,7 @@ memory (e.g. allocated with <function>kmalloc()</function>). There's also </para></listitem> <listitem><para> -<varname>unsigned long addr</varname>: Required if the mapping is used. +<varname>phys_addr_t addr</varname>: Required if the mapping is used. Fill in the address of your memory block. This address is the one that appears in sysfs. </para></listitem> @@ -553,7 +558,7 @@ instead to remember such an address. </itemizedlist> <para> -Please do not touch the <varname>kobj</varname> element of +Please do not touch the <varname>map</varname> element of <varname>struct uio_mem</varname>! It is used by the UIO framework to set up sysfs files for this mapping. Simply leave it alone. </para> @@ -714,6 +719,62 @@ framework to set up sysfs files for this region. Simply leave it alone. </para> </sect1> +<sect1 id="using uio_dmem_genirq"> +<title>Using uio_dmem_genirq for platform devices</title> + <para> + In addition to statically allocated memory ranges, they may also be + a desire to use dynamically allocated regions in a user space driver. + In particular, being able to access memory made available through the + dma-mapping API, may be particularly useful. The + <varname>uio_dmem_genirq</varname> driver provides a way to accomplish + this. + </para> + <para> + This driver is used in a similar manner to the + <varname>"uio_pdrv_genirq"</varname> driver with respect to interrupt + configuration and handling. + </para> + <para> + Set the <varname>.name</varname> element of + <varname>struct platform_device</varname> to + <varname>"uio_dmem_genirq"</varname> to use this driver. + </para> + <para> + When using this driver, fill in the <varname>.platform_data</varname> + element of <varname>struct platform_device</varname>, which is of type + <varname>struct uio_dmem_genirq_pdata</varname> and which contains the + following elements: + </para> + <itemizedlist> + <listitem><varname>struct uio_info uioinfo</varname>: The same + structure used as the <varname>uio_pdrv_genirq</varname> platform + data</listitem> + <listitem><varname>unsigned int *dynamic_region_sizes</varname>: + Pointer to list of sizes of dynamic memory regions to be mapped into + user space. + </listitem> + <listitem><varname>unsigned int num_dynamic_regions</varname>: + Number of elements in <varname>dynamic_region_sizes</varname> array. + </listitem> + </itemizedlist> + <para> + The dynamic regions defined in the platform data will be appended to + the <varname> mem[] </varname> array after the platform device + resources, which implies that the total number of static and dynamic + memory regions cannot exceed <varname>MAX_UIO_MAPS</varname>. + </para> + <para> + The dynamic memory regions will be allocated when the UIO device file, + <varname>/dev/uioX</varname> is opened. + Similar to static memory resources, the memory region information for + dynamic regions is then visible via sysfs at + <varname>/sys/class/uio/uioX/maps/mapY/*</varname>. + The dynamic memory regions will be freed when the UIO device file is + closed. When no processes are holding the device file open, the address + returned to userspace is ~0. + </para> +</sect1> + </chapter> <chapter id="userspace_driver" xreflabel="Writing a driver in user space"> @@ -797,7 +858,7 @@ framework to set up sysfs files for this region. Simply leave it alone. perform some initialization. After that, your hardware starts working and will generate an interrupt as soon as it's finished, has some data available, or needs your - attention because an error occured. + attention because an error occurred. </para> <para> <filename>/dev/uioX</filename> is a read-only file. A @@ -923,7 +984,7 @@ int main() return errno; } configfd = open("/sys/class/uio/uio0/device/config", O_RDWR); - if (uiofd < 0) { + if (configfd < 0) { perror("config open:"); return errno; } |
