- 根目录:
- drivers
- mca
- mca-legacy.c
/* -*- mode: c; c-basic-offset: 8 -*- */
/*
* MCA bus support functions for legacy (2.4) API.
*
* Legacy API means the API that operates in terms of MCA slot number
*
* (C) 2002 James Bottomley <James.Bottomley@HansenPartnership.com>
*
**-----------------------------------------------------------------------------
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
**-----------------------------------------------------------------------------
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/mca-legacy.h>
#include <asm/io.h>
/* NOTE: This structure is stack allocated */
struct mca_find_adapter_info {
int id;
int slot;
struct mca_device *mca_dev;
};
/* The purpose of this iterator is to loop over all the devices and
* find the one with the smallest slot number that's just greater than
* or equal to the required slot with a matching id */
static int mca_find_adapter_callback(struct device *dev, void *data)
{
struct mca_find_adapter_info *info = data;
struct mca_device *mca_dev = to_mca_device(dev);
if(mca_dev->pos_id != info->id)
return 0;
if(mca_dev->slot < info->slot)
return 0;
if(!info->mca_dev || info->mca_dev->slot >= mca_dev->slot)
info->mca_dev = mca_dev;
return 0;
}
/**
* mca_find_adapter - scan for adapters
* @id: MCA identification to search for
* @start: starting slot
*
* Search the MCA configuration for adapters matching the 16bit
* ID given. The first time it should be called with start as zero
* and then further calls made passing the return value of the
* previous call until %MCA_NOTFOUND is returned.
*
* Disabled adapters are not reported.
*/
int mca_find_adapter(int id, int start)
{
struct mca_find_adapter_info info;
if(id == 0xffff)
return MCA_NOTFOUND;
info.slot = start;
info.id = id;
info.mca_dev = NULL;
for(;;) {
bus_for_each_dev(&mca_bus_type, NULL, &info, mca_find_adapter_callback);
if(info.mca_dev == NULL)
return MCA_NOTFOUND;
if(info.mca_dev->status != MCA_ADAPTER_DISABLED)
break;
/* OK, found adapter but it was disabled. Go around
* again, excluding the slot we just found */
info.slot = info.mca_dev->slot + 1;
info.mca_dev = NULL;
}
return info.mca_dev->slot;
}
EXPORT_SYMBOL(mca_find_adapter);
/*--------------------------------------------------------------------*/
/**
* mca_find_unused_adapter - scan for unused adapters
* @id: MCA identification to search for
* @start: starting slot
*
* Search the MCA configuration for adapters matching the 16bit
* ID given. The first time it should be called with start as zero
* and then further calls made passing the return value of the
* previous call until %MCA_NOTFOUND is returned.
*
* Adapters that have been claimed by drivers and those that
* are disabled are not reported. This function thus allows a driver
* to scan for further cards when some may already be driven.
*/
int mca_find_unused_adapter(int id, int start)
{
struct mca_find_adapter_info info = { 0 };
if (!MCA_bus || id == 0xffff)
return MCA_NOTFOUND;
info.slot = start;
info.id = id;
info.mca_dev = NULL;
for(;;) {
bus_for_each_dev(&mca_bus_type, NULL, &info, mca_find_adapter_callback);
if(info.mca_dev == NULL)
return MCA_NOTFOUND;
if(info.mca_dev->status != MCA_ADAPTER_DISABLED
&& !info.mca_dev->driver_loaded)
break;
/* OK, found adapter but it was disabled or already in
* use. Go around again, excluding the slot we just
* found */
info.slot = info.mca_dev->slot + 1;
info.mca_dev = NULL;
}
return info.mca_dev->slot;
}
EXPORT_SYMBOL(mca_find_unused_adapter);
/* NOTE: stack allocated structure */
struct mca_find_device_by_slot_info {
int slot;
struct mca_device *mca_dev;
};
static int mca_find_device_by_slot_callback(struct device *dev, void *data)
{
struct mca_find_device_by_slot_info *info = data;
struct mca_device *mca_dev = to_mca_device(dev);
if(mca_dev->slot == info->slot)
info->mca_dev = mca_dev;
return 0;
}
struct mca_device *mca_find_device_by_slot(int slot)
{
struct mca_find_device_by_slot_info info;
info.slot = slot;
info.mca_dev = NULL;
bus_for_each_dev(&mca_bus_type, NULL, &info, mca_find_device_by_slot_callback);
return info.mca_dev;
}
/**
* mca_read_stored_pos - read POS register from boot data
* @slot: slot number to read from
* @reg: register to read from
*
* Fetch a POS value that was stored at boot time by the kernel
* when it scanned the MCA space. The register value is returned.
* Missing or invalid registers report 0.
*/
unsigned char mca_read_stored_pos(int slot, int reg)
{
struct mca_device *mca_dev = mca_find_device_by_slot(slot);
if(!mca_dev)
return 0;
return mca_device_read_stored_pos(mca_dev, reg);
}
EXPORT_SYMBOL(mca_read_stored_pos);
/**
* mca_read_pos - read POS register from card
* @slot: slot number to read from
* @reg: register to read from
*
* Fetch a POS value directly from the hardware to obtain the
* current value. This is much slower than mca_read_stored_pos and
* may not be invoked from interrupt context. It handles the
* deep magic required for onboard devices transparently.
*/
unsigned char mca_read_pos(int slot, int reg)
{
struct mca_device *mca_dev = mca_find_device_by_slot(slot);
if(!mca_dev)
return 0;
return mca_device_read_pos(mca_dev, reg);
}
EXPORT_SYMBOL(mca_read_pos);
/**
* mca_write_pos - read POS register from card
* @slot: slot number to read from
* @reg: register to read from
* @byte: byte to write to the POS registers
*
* Store a POS value directly from the hardware. You should not
* normally need to use this function and should have a very good
* knowledge of MCA bus before you do so. Doing this wrongly can
* damage the hardware.
*
* This function may not be used from interrupt context.
*
* Note that this a technically a Bad Thing, as IBM tech stuff says
* you should only set POS values through their utilities.
* However, some devices such as the 3c523 recommend that you write
* back some data to make sure the configuration is consistent.
* I'd say that IBM is right, but I like my drivers to work.
*
* This function can't do checks to see if multiple devices end up
* with the same resources, so you might see magic smoke if someone
* screws up.
*/
void mca_write_pos(int slot, int reg, unsigned char byte)
{
struct mca_device *mca_dev = mca_find_device_by_slot(slot);
if(!mca_dev)
return;
mca_device_write_pos(mca_dev, reg, byte);
}
EXPORT_SYMBOL(mca_write_pos);
/**
* mca_set_adapter_name - Set the description of the card
* @slot: slot to name
* @name: text string for the namen
*
* This function sets the name reported via /proc for this
* adapter slot. This is for user information only. Setting a
* name deletes any previous name.
*/
void mca_set_adapter_name(int slot, char* name)
{
struct mca_device *mca_dev = mca_find_device_by_slot(slot);
if(!mca_dev)
return;
mca_device_set_name(mca_dev, name);
}
EXPORT_SYMBOL(mca_set_adapter_name);
/**
* mca_mark_as_used - claim an MCA device
* @slot: slot to claim
* FIXME: should we make this threadsafe
*
* Claim an MCA slot for a device driver. If the
* slot is already taken the function returns 1,
* if it is not taken it is claimed and 0 is
* returned.
*/
int mca_mark_as_used(int slot)
{
struct mca_device *mca_dev = mca_find_device_by_slot(slot);
if(!mca_dev)
/* FIXME: this is actually a severe error */
return 1;
if(mca_device_claimed(mca_dev))
return 1;
mca_device_set_claim(mca_dev, 1);
return 0;
}
EXPORT_SYMBOL(mca_mark_as_used);
/**
* mca_mark_as_unused - release an MCA device
* @slot: slot to claim
*
* Release the slot for other drives to use.
*/
void mca_mark_as_unused(int slot)
{
struct mca_device *mca_dev = mca_find_device_by_slot(slot);
if(!mca_dev)
return;
mca_device_set_claim(mca_dev, 0);
}
EXPORT_SYMBOL(mca_mark_as_unused);