linux/drivers/base/isa.c
Rene Herman 00412be1d7 isa: set 24-bit dma_mask for ISA devices
dma_alloc_coherent() on x86 currently takes a passed in NULL device
pointer to mean that it should allocate an ISA compatible (24-bit) buffer
which is a bit of a hack.

The ALSA ISA drivers are the main consumers of this but have a struct
device in fact readily available.

For the legacy drivers, this sets the device dma_mask in preparation for
using the actual device with the DMA API so as to eventually not need the
NULL hack in dma_alloc_coherent().

This does not fix a current bug -- 2.6.26-rc1 stumbled over the NULL hack
in dma_alloc_coherent() but this has already been fixed in commit
4a367f3a9d by Takashi Iwai.

Signed-off-by: Rene Herman <rene.herman@gmail.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:02 -07:00

185 lines
3.7 KiB
C

/*
* ISA bus.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/isa.h>
static struct device isa_bus = {
.bus_id = "isa"
};
struct isa_dev {
struct device dev;
struct device *next;
unsigned int id;
};
#define to_isa_dev(x) container_of((x), struct isa_dev, dev)
static int isa_bus_match(struct device *dev, struct device_driver *driver)
{
struct isa_driver *isa_driver = to_isa_driver(driver);
if (dev->platform_data == isa_driver) {
if (!isa_driver->match ||
isa_driver->match(dev, to_isa_dev(dev)->id))
return 1;
dev->platform_data = NULL;
}
return 0;
}
static int isa_bus_probe(struct device *dev)
{
struct isa_driver *isa_driver = dev->platform_data;
if (isa_driver->probe)
return isa_driver->probe(dev, to_isa_dev(dev)->id);
return 0;
}
static int isa_bus_remove(struct device *dev)
{
struct isa_driver *isa_driver = dev->platform_data;
if (isa_driver->remove)
return isa_driver->remove(dev, to_isa_dev(dev)->id);
return 0;
}
static void isa_bus_shutdown(struct device *dev)
{
struct isa_driver *isa_driver = dev->platform_data;
if (isa_driver->shutdown)
isa_driver->shutdown(dev, to_isa_dev(dev)->id);
}
static int isa_bus_suspend(struct device *dev, pm_message_t state)
{
struct isa_driver *isa_driver = dev->platform_data;
if (isa_driver->suspend)
return isa_driver->suspend(dev, to_isa_dev(dev)->id, state);
return 0;
}
static int isa_bus_resume(struct device *dev)
{
struct isa_driver *isa_driver = dev->platform_data;
if (isa_driver->resume)
return isa_driver->resume(dev, to_isa_dev(dev)->id);
return 0;
}
static struct bus_type isa_bus_type = {
.name = "isa",
.match = isa_bus_match,
.probe = isa_bus_probe,
.remove = isa_bus_remove,
.shutdown = isa_bus_shutdown,
.suspend = isa_bus_suspend,
.resume = isa_bus_resume
};
static void isa_dev_release(struct device *dev)
{
kfree(to_isa_dev(dev));
}
void isa_unregister_driver(struct isa_driver *isa_driver)
{
struct device *dev = isa_driver->devices;
while (dev) {
struct device *tmp = to_isa_dev(dev)->next;
device_unregister(dev);
dev = tmp;
}
driver_unregister(&isa_driver->driver);
}
EXPORT_SYMBOL_GPL(isa_unregister_driver);
int isa_register_driver(struct isa_driver *isa_driver, unsigned int ndev)
{
int error;
unsigned int id;
isa_driver->driver.bus = &isa_bus_type;
isa_driver->devices = NULL;
error = driver_register(&isa_driver->driver);
if (error)
return error;
for (id = 0; id < ndev; id++) {
struct isa_dev *isa_dev;
isa_dev = kzalloc(sizeof *isa_dev, GFP_KERNEL);
if (!isa_dev) {
error = -ENOMEM;
break;
}
isa_dev->dev.parent = &isa_bus;
isa_dev->dev.bus = &isa_bus_type;
snprintf(isa_dev->dev.bus_id, BUS_ID_SIZE, "%s.%u",
isa_driver->driver.name, id);
isa_dev->dev.platform_data = isa_driver;
isa_dev->dev.release = isa_dev_release;
isa_dev->id = id;
isa_dev->dev.coherent_dma_mask = DMA_24BIT_MASK;
isa_dev->dev.dma_mask = &isa_dev->dev.coherent_dma_mask;
error = device_register(&isa_dev->dev);
if (error) {
put_device(&isa_dev->dev);
break;
}
if (isa_dev->dev.platform_data) {
isa_dev->next = isa_driver->devices;
isa_driver->devices = &isa_dev->dev;
} else
device_unregister(&isa_dev->dev);
}
if (!error && !isa_driver->devices)
error = -ENODEV;
if (error)
isa_unregister_driver(isa_driver);
return error;
}
EXPORT_SYMBOL_GPL(isa_register_driver);
static int __init isa_bus_init(void)
{
int error;
error = bus_register(&isa_bus_type);
if (!error) {
error = device_register(&isa_bus);
if (error)
bus_unregister(&isa_bus_type);
}
return error;
}
device_initcall(isa_bus_init);