33d8675ea6
Remove the assumption that driver_register() returns the number of devices bound to the driver. In fact, it returns zero for success or a negative error value. zorro_module_init() used the device count to automatically unregister and unload drivers that found no devices. That might have worked at one time, but has been broken for some time because zorro_register_driver() returned either a negative error or a positive count (never zero). So it could only unregister on failure, when it's not needed anyway. This functionality could be resurrected in individual drivers by counting devices in their .probe() methods. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
146 lines
3.6 KiB
C
146 lines
3.6 KiB
C
/*
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* Zorro Driver Services
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*
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* Copyright (C) 2003 Geert Uytterhoeven
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*
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* Loosely based on drivers/pci/pci-driver.c
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/zorro.h>
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/**
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* zorro_match_device - Tell if a Zorro device structure has a matching
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* Zorro device id structure
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* @ids: array of Zorro device id structures to search in
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* @dev: the Zorro device structure to match against
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*
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* Used by a driver to check whether a Zorro device present in the
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* system is in its list of supported devices. Returns the matching
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* zorro_device_id structure or %NULL if there is no match.
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*/
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const struct zorro_device_id *
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zorro_match_device(const struct zorro_device_id *ids,
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const struct zorro_dev *z)
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{
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while (ids->id) {
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if (ids->id == ZORRO_WILDCARD || ids->id == z->id)
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return ids;
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ids++;
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}
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return NULL;
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}
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static int zorro_device_probe(struct device *dev)
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{
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int error = 0;
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struct zorro_driver *drv = to_zorro_driver(dev->driver);
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struct zorro_dev *z = to_zorro_dev(dev);
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if (!z->driver && drv->probe) {
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const struct zorro_device_id *id;
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id = zorro_match_device(drv->id_table, z);
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if (id)
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error = drv->probe(z, id);
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if (error >= 0) {
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z->driver = drv;
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error = 0;
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}
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}
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return error;
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}
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/**
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* zorro_register_driver - register a new Zorro driver
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* @drv: the driver structure to register
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*
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* Adds the driver structure to the list of registered drivers
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* Returns zero or a negative error value.
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*/
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int zorro_register_driver(struct zorro_driver *drv)
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{
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/* initialize common driver fields */
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drv->driver.name = drv->name;
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drv->driver.bus = &zorro_bus_type;
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/* register with core */
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return driver_register(&drv->driver);
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}
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/**
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* zorro_unregister_driver - unregister a zorro driver
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* @drv: the driver structure to unregister
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*
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* Deletes the driver structure from the list of registered Zorro drivers,
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* gives it a chance to clean up by calling its remove() function for
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* each device it was responsible for, and marks those devices as
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* driverless.
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*/
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void zorro_unregister_driver(struct zorro_driver *drv)
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{
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driver_unregister(&drv->driver);
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}
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/**
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* zorro_bus_match - Tell if a Zorro device structure has a matching Zorro
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* device id structure
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* @ids: array of Zorro device id structures to search in
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* @dev: the Zorro device structure to match against
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*
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* Used by a driver to check whether a Zorro device present in the
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* system is in its list of supported devices.Returns the matching
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* zorro_device_id structure or %NULL if there is no match.
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*/
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static int zorro_bus_match(struct device *dev, struct device_driver *drv)
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{
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struct zorro_dev *z = to_zorro_dev(dev);
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struct zorro_driver *zorro_drv = to_zorro_driver(drv);
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const struct zorro_device_id *ids = zorro_drv->id_table;
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if (!ids)
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return 0;
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while (ids->id) {
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if (ids->id == ZORRO_WILDCARD || ids->id == z->id)
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return 1;
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ids++;
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}
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return 0;
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}
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struct bus_type zorro_bus_type = {
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.name = "zorro",
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.match = zorro_bus_match,
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.probe = zorro_device_probe,
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};
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static int __init zorro_driver_init(void)
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{
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return bus_register(&zorro_bus_type);
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}
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postcore_initcall(zorro_driver_init);
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EXPORT_SYMBOL(zorro_match_device);
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EXPORT_SYMBOL(zorro_register_driver);
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EXPORT_SYMBOL(zorro_unregister_driver);
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EXPORT_SYMBOL(zorro_dev_driver);
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EXPORT_SYMBOL(zorro_bus_type);
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