[PATCH] pcmcia: add some Documentation

Add some information useful for PCMCIA device driver authors to
Documentation/pcmcia/, and reference it in dmesg in case of hash mismatches.

Also add a reference to pcmciautils to Documentation/Changes.  With recent
changes, you don't need to concern yourself with pcmcia-cs even if you have
PCMCIA hardware, so the example above the list needed to be adapted as well.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowksi.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 115 insertions, 0 deletions

diff --git a/Documentation/pcmcia/devicetable.txt b/Documentation/pcmcia/devicetable.txt
new file mode 100644
index 000000000000..7225f9eddf9d
--- /dev/null
+++ b/Documentation/pcmcia/devicetable.txt
@@ -0,0 +1,64 @@
+Matching of PCMCIA devices to drivers is done using one or more of the
+following criteria:
+
+- manufactor ID
+- card ID
+- product ID strings _and_ hashes of these strings
+- function ID
+- device function (actual and pseudo)
+
+You should use the helpers in include/pcmcia/device_id.h for generating the
+struct pcmcia_device_id[] entries which match devices to drivers.
+
+If you want to match product ID strings, you also need to pass the crc32
+hashes of the string to the macro, e.g. if you want to match the product ID
+string 1, you need to use
+
+PCMCIA_DEVICE_PROD_ID1("some_string", 0x(hash_of_some_string)),
+
+If the hash is incorrect, the kernel will inform you about this in "dmesg"
+upon module initialization, and tell you of the correct hash.
+
+You can determine the hash of the product ID strings by running
+"pcmcia-modalias %n.%m" [%n being replaced with the socket number and %m being
+replaced with the device function] from pcmciautils. It generates a string
+in the following form:
+pcmcia:m0149cC1ABf06pfn00fn00pa725B842DpbF1EFEE84pc0877B627pd00000000
+
+The hex value after "pa" is the hash of product ID string 1, after "pb" for
+string 2 and so on.
+
+Alternatively, you can use this small tool to determine the crc32 hash.
+simply pass the string you want to evaluate as argument to this program,
+e.g.
+$ ./crc32hash "Dual Speed"
+
+-------------------------------------------------------------------------
+/* crc32hash.c - derived from linux/lib/crc32.c, GNU GPL v2 */
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <stdlib.h>
+
+unsigned int crc32(unsigned char const *p, unsigned int len)
+{
+	int i;
+	unsigned int crc = 0;
+	while (len--)
+		crc ^= *p++;
+		for (i = 0; i < 8; i++)
+			crc = (crc >> 1) ^ ((crc & 1) ? 0xedb88320 : 0);
+	}
+	return crc;
+}
+
+int main(int argc, char **argv) {
+	unsigned int result;
+	if (argc != 2) {
+		printf("no string passed as argument\n");
+		return -1;
+	}
+	result = crc32(argv[1], strlen(argv[1]));
+	printf("0x%x\n", result);
+	return 0;
+}
diff --git a/Documentation/pcmcia/driver-changes.txt b/Documentation/pcmcia/driver-changes.txt
new file mode 100644
index 000000000000..9c315ab48a02
--- /dev/null
+++ b/Documentation/pcmcia/driver-changes.txt
@@ -0,0 +1,51 @@
+This file details changes in 2.6 which affect PCMCIA card driver authors:
+
+* in-kernel device<->driver matching
+   PCMCIA devices and their correct drivers can now be matched in
+   kernelspace. See 'devicetable.txt' for details.
+
+* Device model integration (as of 2.6.11)
+   A struct pcmcia_device is registered with the device model core,
+   and can be used (e.g. for SET_NETDEV_DEV) by using
+   handle_to_dev(client_handle_t * handle).
+
+* Convert internal I/O port addresses to unsigned long (as of 2.6.11)
+   ioaddr_t should be replaced by kio_addr_t in PCMCIA card drivers.
+
+* irq_mask and irq_list parameters (as of 2.6.11)
+   The irq_mask and irq_list parameters should no longer be used in
+   PCMCIA card drivers. Instead, it is the job of the PCMCIA core to
+   determine which IRQ should be used. Therefore, link->irq.IRQInfo2
+   is ignored.
+
+* client->PendingEvents is gone (as of 2.6.11)
+   client->PendingEvents is no longer available.
+
+* client->Attributes are gone (as of 2.6.11)
+   client->Attributes is unused, therefore it is removed from all
+   PCMCIA card drivers
+
+* core functions no longer available (as of 2.6.11)
+   The following functions have been removed from the kernel source
+   because they are unused by all in-kernel drivers, and no external
+   driver was reported to rely on them:
+	pcmcia_get_first_region()
+	pcmcia_get_next_region()
+	pcmcia_modify_window()
+	pcmcia_set_event_mask()
+	pcmcia_get_first_window()
+	pcmcia_get_next_window()
+
+* device list iteration upon module removal (as of 2.6.10)
+   It is no longer necessary to iterate on the driver's internal
+   client list and call the ->detach() function upon module removal.
+
+* Resource management. (as of 2.6.8)
+   Although the PCMCIA subsystem will allocate resources for cards,
+   it no longer marks these resources busy. This means that driver
+   authors are now responsible for claiming your resources as per
+   other drivers in Linux. You should use request_region() to mark
+   your IO regions in-use, and request_mem_region() to mark your
+   memory regions in-use. The name argument should be a pointer to
+   your driver name. Eg, for pcnet_cs, name should point to the
+   string "pcnet_cs".