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authorLinus Torvalds2019-07-16 21:21:41 +0200
committerLinus Torvalds2019-07-16 21:21:41 +0200
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Merge tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull rst conversion of docs from Mauro Carvalho Chehab: "As agreed with Jon, I'm sending this big series directly to you, c/c him, as this series required a special care, in order to avoid conflicts with other trees" * tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (77 commits) docs: kbuild: fix build with pdf and fix some minor issues docs: block: fix pdf output docs: arm: fix a breakage with pdf output docs: don't use nested tables docs: gpio: add sysfs interface to the admin-guide docs: locking: add it to the main index docs: add some directories to the main documentation index docs: add SPDX tags to new index files docs: add a memory-devices subdir to driver-api docs: phy: place documentation under driver-api docs: serial: move it to the driver-api docs: driver-api: add remaining converted dirs to it docs: driver-api: add xilinx driver API documentation docs: driver-api: add a series of orphaned documents docs: admin-guide: add a series of orphaned documents docs: cgroup-v1: add it to the admin-guide book docs: aoe: add it to the driver-api book docs: add some documentation dirs to the driver-api book docs: driver-model: move it to the driver-api book docs: lp855x-driver.rst: add it to the driver-api book ...
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+========================================
+Writing Device Drivers for Zorro Devices
+========================================
+
+:Author: Written by Geert Uytterhoeven <geert@linux-m68k.org>
+:Last revised: September 5, 2003
+
+
+Introduction
+------------
+
+The Zorro bus is the bus used in the Amiga family of computers. Thanks to
+AutoConfig(tm), it's 100% Plug-and-Play.
+
+There are two types of Zorro buses, Zorro II and Zorro III:
+
+ - The Zorro II address space is 24-bit and lies within the first 16 MB of the
+ Amiga's address map.
+
+ - Zorro III is a 32-bit extension of Zorro II, which is backwards compatible
+ with Zorro II. The Zorro III address space lies outside the first 16 MB.
+
+
+Probing for Zorro Devices
+-------------------------
+
+Zorro devices are found by calling ``zorro_find_device()``, which returns a
+pointer to the ``next`` Zorro device with the specified Zorro ID. A probe loop
+for the board with Zorro ID ``ZORRO_PROD_xxx`` looks like::
+
+ struct zorro_dev *z = NULL;
+
+ while ((z = zorro_find_device(ZORRO_PROD_xxx, z))) {
+ if (!zorro_request_region(z->resource.start+MY_START, MY_SIZE,
+ "My explanation"))
+ ...
+ }
+
+``ZORRO_WILDCARD`` acts as a wildcard and finds any Zorro device. If your driver
+supports different types of boards, you can use a construct like::
+
+ struct zorro_dev *z = NULL;
+
+ while ((z = zorro_find_device(ZORRO_WILDCARD, z))) {
+ if (z->id != ZORRO_PROD_xxx1 && z->id != ZORRO_PROD_xxx2 && ...)
+ continue;
+ if (!zorro_request_region(z->resource.start+MY_START, MY_SIZE,
+ "My explanation"))
+ ...
+ }
+
+
+Zorro Resources
+---------------
+
+Before you can access a Zorro device's registers, you have to make sure it's
+not yet in use. This is done using the I/O memory space resource management
+functions::
+
+ request_mem_region()
+ release_mem_region()
+
+Shortcuts to claim the whole device's address space are provided as well::
+
+ zorro_request_device
+ zorro_release_device
+
+
+Accessing the Zorro Address Space
+---------------------------------
+
+The address regions in the Zorro device resources are Zorro bus address
+regions. Due to the identity bus-physical address mapping on the Zorro bus,
+they are CPU physical addresses as well.
+
+The treatment of these regions depends on the type of Zorro space:
+
+ - Zorro II address space is always mapped and does not have to be mapped
+ explicitly using z_ioremap().
+
+ Conversion from bus/physical Zorro II addresses to kernel virtual addresses
+ and vice versa is done using::
+
+ virt_addr = ZTWO_VADDR(bus_addr);
+ bus_addr = ZTWO_PADDR(virt_addr);
+
+ - Zorro III address space must be mapped explicitly using z_ioremap() first
+ before it can be accessed::
+
+ virt_addr = z_ioremap(bus_addr, size);
+ ...
+ z_iounmap(virt_addr);
+
+
+References
+----------
+
+#. linux/include/linux/zorro.h
+#. linux/include/uapi/linux/zorro.h
+#. linux/include/uapi/linux/zorro_ids.h
+#. linux/arch/m68k/include/asm/zorro.h
+#. linux/drivers/zorro
+#. /proc/bus/zorro
+