linux/drivers/pnp/driver.c
Bjorn Helgaas b173491339 PNP: remove null pointer checks
Remove some null pointer checks.  Null pointers in these areas indicate
programming errors, and I think it's better to oops immediately rather
than return an error that is easily ignored.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2007-08-24 01:27:24 -04:00

250 lines
5.1 KiB
C

/*
* driver.c - device id matching, driver model, etc.
*
* Copyright 2002 Adam Belay <ambx1@neo.rr.com>
*/
#include <linux/string.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/pnp.h>
#include "base.h"
static int compare_func(const char *ida, const char *idb)
{
int i;
/* we only need to compare the last 4 chars */
for (i = 3; i < 7; i++) {
if (ida[i] != 'X' &&
idb[i] != 'X' && toupper(ida[i]) != toupper(idb[i]))
return 0;
}
return 1;
}
int compare_pnp_id(struct pnp_id *pos, const char *id)
{
if (!pos || !id || (strlen(id) != 7))
return 0;
if (memcmp(id, "ANYDEVS", 7) == 0)
return 1;
while (pos) {
if (memcmp(pos->id, id, 3) == 0)
if (compare_func(pos->id, id) == 1)
return 1;
pos = pos->next;
}
return 0;
}
static const struct pnp_device_id *match_device(struct pnp_driver *drv,
struct pnp_dev *dev)
{
const struct pnp_device_id *drv_id = drv->id_table;
if (!drv_id)
return NULL;
while (*drv_id->id) {
if (compare_pnp_id(dev->id, drv_id->id))
return drv_id;
drv_id++;
}
return NULL;
}
int pnp_device_attach(struct pnp_dev *pnp_dev)
{
spin_lock(&pnp_lock);
if (pnp_dev->status != PNP_READY) {
spin_unlock(&pnp_lock);
return -EBUSY;
}
pnp_dev->status = PNP_ATTACHED;
spin_unlock(&pnp_lock);
return 0;
}
void pnp_device_detach(struct pnp_dev *pnp_dev)
{
spin_lock(&pnp_lock);
if (pnp_dev->status == PNP_ATTACHED)
pnp_dev->status = PNP_READY;
spin_unlock(&pnp_lock);
pnp_disable_dev(pnp_dev);
}
static int pnp_device_probe(struct device *dev)
{
int error;
struct pnp_driver *pnp_drv;
struct pnp_dev *pnp_dev;
const struct pnp_device_id *dev_id = NULL;
pnp_dev = to_pnp_dev(dev);
pnp_drv = to_pnp_driver(dev->driver);
pnp_dbg("match found with the PnP device '%s' and the driver '%s'",
dev->bus_id, pnp_drv->name);
error = pnp_device_attach(pnp_dev);
if (error < 0)
return error;
if (pnp_dev->active == 0) {
if (!(pnp_drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)) {
error = pnp_activate_dev(pnp_dev);
if (error < 0)
return error;
}
} else if ((pnp_drv->flags & PNP_DRIVER_RES_DISABLE)
== PNP_DRIVER_RES_DISABLE) {
error = pnp_disable_dev(pnp_dev);
if (error < 0)
return error;
}
error = 0;
if (pnp_drv->probe) {
dev_id = match_device(pnp_drv, pnp_dev);
if (dev_id != NULL)
error = pnp_drv->probe(pnp_dev, dev_id);
}
if (error >= 0) {
pnp_dev->driver = pnp_drv;
error = 0;
} else
goto fail;
return error;
fail:
pnp_device_detach(pnp_dev);
return error;
}
static int pnp_device_remove(struct device *dev)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *drv = pnp_dev->driver;
if (drv) {
if (drv->remove)
drv->remove(pnp_dev);
pnp_dev->driver = NULL;
}
pnp_device_detach(pnp_dev);
return 0;
}
static int pnp_bus_match(struct device *dev, struct device_driver *drv)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *pnp_drv = to_pnp_driver(drv);
if (match_device(pnp_drv, pnp_dev) == NULL)
return 0;
return 1;
}
static int pnp_bus_suspend(struct device *dev, pm_message_t state)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *pnp_drv = pnp_dev->driver;
int error;
if (!pnp_drv)
return 0;
if (pnp_drv->suspend) {
error = pnp_drv->suspend(pnp_dev, state);
if (error)
return error;
}
if (!(pnp_drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE) &&
pnp_can_disable(pnp_dev)) {
error = pnp_stop_dev(pnp_dev);
if (error)
return error;
}
if (pnp_dev->protocol && pnp_dev->protocol->suspend)
pnp_dev->protocol->suspend(pnp_dev, state);
return 0;
}
static int pnp_bus_resume(struct device *dev)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *pnp_drv = pnp_dev->driver;
int error;
if (!pnp_drv)
return 0;
if (pnp_dev->protocol && pnp_dev->protocol->resume)
pnp_dev->protocol->resume(pnp_dev);
if (!(pnp_drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)) {
error = pnp_start_dev(pnp_dev);
if (error)
return error;
}
if (pnp_drv->resume)
return pnp_drv->resume(pnp_dev);
return 0;
}
struct bus_type pnp_bus_type = {
.name = "pnp",
.match = pnp_bus_match,
.probe = pnp_device_probe,
.remove = pnp_device_remove,
.suspend = pnp_bus_suspend,
.resume = pnp_bus_resume,
};
int pnp_register_driver(struct pnp_driver *drv)
{
pnp_dbg("the driver '%s' has been registered", drv->name);
drv->driver.name = drv->name;
drv->driver.bus = &pnp_bus_type;
return driver_register(&drv->driver);
}
void pnp_unregister_driver(struct pnp_driver *drv)
{
driver_unregister(&drv->driver);
pnp_dbg("the driver '%s' has been unregistered", drv->name);
}
/**
* pnp_add_id - adds an EISA id to the specified device
* @id: pointer to a pnp_id structure
* @dev: pointer to the desired device
*/
int pnp_add_id(struct pnp_id *id, struct pnp_dev *dev)
{
struct pnp_id *ptr;
id->next = NULL;
ptr = dev->id;
while (ptr && ptr->next)
ptr = ptr->next;
if (ptr)
ptr->next = id;
else
dev->id = id;
return 0;
}
EXPORT_SYMBOL(pnp_register_driver);
EXPORT_SYMBOL(pnp_unregister_driver);
EXPORT_SYMBOL(pnp_device_attach);
EXPORT_SYMBOL(pnp_device_detach);