diff options
Diffstat (limited to 'drivers/mca/mca-legacy.c')
| -rw-r--r-- | drivers/mca/mca-legacy.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/drivers/mca/mca-legacy.c b/drivers/mca/mca-legacy.c new file mode 100644 index 000000000000..af56313ba0af --- /dev/null +++ b/drivers/mca/mca-legacy.c @@ -0,0 +1,348 @@ +/* -*- 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; +} +EXPORT_SYMBOL(mca_find_device_by_slot); + +/** + * 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_is_adapter_used - check if claimed by driver + * @slot: slot to check + * + * Returns 1 if the slot has been claimed by a driver + */ + +int mca_is_adapter_used(int slot) +{ + struct mca_device *mca_dev = mca_find_device_by_slot(slot); + + if(!mca_dev) + return 0; + + return mca_device_claimed(mca_dev); +} +EXPORT_SYMBOL(mca_is_adapter_used); + +/** + * 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); + |