Introduction¶

The Zorro bus is the bus used in the Amiga family of computers. Thanks toAutoConfig(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 theAmiga’s address map.
• Zorro III is a 32-bit extension of Zorro II, which is backwards compatiblewith Zorro II. The Zorro III address space lies outside the first 16 MB.

Probing for Zorro Devices¶

Zorro devices are found by callingzorro_find_device(), which returns apointer to thenext Zorro device with the specified Zorro ID. A probe loopfor the board with Zorro IDZORRO_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 driversupports 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’snot yet in use. This is done using the I/O memory space resource managementfunctions:

request_mem_region()release_mem_region()

Shortcuts to claim the whole device’s address space are provided as well:

zorro_request_devicezorro_release_device

Accessing the Zorro Address Space¶

The address regions in the Zorro device resources are Zorro bus addressregions. 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 mappedexplicitly using z_ioremap().

  Conversion from bus/physical Zorro II addresses to kernel virtual addressesand 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() firstbefore it can be accessed:

  virt_addr = z_ioremap(bus_addr, size);...z_iounmap(virt_addr);

References¶

1. linux/include/linux/zorro.h
2. linux/include/uapi/linux/zorro.h
3. linux/include/uapi/linux/zorro_ids.h
4. linux/arch/m68k/include/asm/zorro.h
5. linux/drivers/zorro
6. /proc/bus/zorro