mm: fix truncate_setsize() comment

[linux-2.6/next.git] / drivers / pcmcia / pcmcia_resource.c

/*
 * PCMCIA 16-bit resource management functions
 *
 * The initial developer of the original code is David A. Hinds
 * <dahinds@users.sourceforge.net>.  Portions created by David A. Hinds
 * are Copyright (C) 1999 David A. Hinds.  All Rights Reserved.
 *
 * Copyright (C) 1999        David A. Hinds
 * Copyright (C) 2004-2010   Dominik Brodowski
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/device.h>
#include <linux/netdevice.h>
#include <linux/slab.h>

#include <asm/irq.h>

#include <pcmcia/ss.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/cisreg.h>
#include <pcmcia/ds.h>

#include "cs_internal.h"


/* Access speed for IO windows */
static int io_speed;
module_param(io_speed, int, 0444);


int pcmcia_validate_mem(struct pcmcia_socket *s)
{
        if (s->resource_ops->validate_mem)
                return s->resource_ops->validate_mem(s);
        /* if there is no callback, we can assume that everything is OK */
        return 0;
}

struct resource *pcmcia_find_mem_region(u_long base, u_long num, u_long align,
                                 int low, struct pcmcia_socket *s)
{
        if (s->resource_ops->find_mem)
                return s->resource_ops->find_mem(base, num, align, low, s);
        return NULL;
}


/**
 * release_io_space() - release IO ports allocated with alloc_io_space()
 * @s: pcmcia socket
 * @res: resource to release
 *
 */
static void release_io_space(struct pcmcia_socket *s, struct resource *res)
{
        resource_size_t num = resource_size(res);
        int i;

        dev_dbg(&s->dev, "release_io_space for %pR\n", res);

        for (i = 0; i < MAX_IO_WIN; i++) {
                if (!s->io[i].res)
                        continue;
                if ((s->io[i].res->start <= res->start) &&
                    (s->io[i].res->end >= res->end)) {
                        s->io[i].InUse -= num;
                        if (res->parent)
                                release_resource(res);
                        res->start = res->end = 0;
                        res->flags = IORESOURCE_IO;
                        /* Free the window if no one else is using it */
                        if (s->io[i].InUse == 0) {
                                release_resource(s->io[i].res);
                                kfree(s->io[i].res);
                                s->io[i].res = NULL;
                        }
                }
        }
}


/**
 * alloc_io_space() - allocate IO ports for use by a PCMCIA device
 * @s: pcmcia socket
 * @res: resource to allocate (begin: begin, end: size)
 * @lines: number of IO lines decoded by the PCMCIA card
 *
 * Special stuff for managing IO windows, because they are scarce
 */
static int alloc_io_space(struct pcmcia_socket *s, struct resource *res,
                        unsigned int lines)
{
        unsigned int align;
        unsigned int base = res->start;
        unsigned int num = res->end;
        int ret;

        res->flags |= IORESOURCE_IO;

        dev_dbg(&s->dev, "alloc_io_space request for %pR, %d lines\n",
                res, lines);

        align = base ? (lines ? 1<<lines : 0) : 1;
        if (align && (align < num)) {
                if (base) {
                        dev_dbg(&s->dev, "odd IO request\n");
                        align = 0;
                } else
                        while (align && (align < num))
                                align <<= 1;
        }
        if (base & ~(align-1)) {
                dev_dbg(&s->dev, "odd IO request\n");
                align = 0;
        }

        ret = s->resource_ops->find_io(s, res->flags, &base, num, align,
                                &res->parent);
        if (ret) {
                dev_dbg(&s->dev, "alloc_io_space request failed (%d)\n", ret);
                return -EINVAL;
        }

        res->start = base;
        res->end = res->start + num - 1;

        if (res->parent) {
                ret = request_resource(res->parent, res);
                if (ret) {
                        dev_warn(&s->dev,
                                "request_resource %pR failed: %d\n", res, ret);
                        res->parent = NULL;
                        release_io_space(s, res);
                }
        }
        dev_dbg(&s->dev, "alloc_io_space request result %d: %pR\n", ret, res);
        return ret;
}


/**
 * pcmcia_access_config() - read or write card configuration registers
 *
 * pcmcia_access_config() reads and writes configuration registers in
 * attribute memory.  Memory window 0 is reserved for this and the tuple
 * reading services. Drivers must use pcmcia_read_config_byte() or
 * pcmcia_write_config_byte().
 */
static int pcmcia_access_config(struct pcmcia_device *p_dev,
                                off_t where, u8 *val,
                                int (*accessf) (struct pcmcia_socket *s,
                                                int attr, unsigned int addr,
                                                unsigned int len, void *ptr))
{
        struct pcmcia_socket *s;
        config_t *c;
        int addr;
        int ret = 0;

        s = p_dev->socket;

        mutex_lock(&s->ops_mutex);
        c = p_dev->function_config;

        if (!(c->state & CONFIG_LOCKED)) {
                dev_dbg(&p_dev->dev, "Configuration isnt't locked\n");
                mutex_unlock(&s->ops_mutex);
                return -EACCES;
        }

        addr = (p_dev->config_base + where) >> 1;

        ret = accessf(s, 1, addr, 1, val);

        mutex_unlock(&s->ops_mutex);

        return ret;
}


/**
 * pcmcia_read_config_byte() - read a byte from a card configuration register
 *
 * pcmcia_read_config_byte() reads a byte from a configuration register in
 * attribute memory.
 */
int pcmcia_read_config_byte(struct pcmcia_device *p_dev, off_t where, u8 *val)
{
        return pcmcia_access_config(p_dev, where, val, pcmcia_read_cis_mem);
}
EXPORT_SYMBOL(pcmcia_read_config_byte);


/**
 * pcmcia_write_config_byte() - write a byte to a card configuration register
 *
 * pcmcia_write_config_byte() writes a byte to a configuration register in
 * attribute memory.
 */
int pcmcia_write_config_byte(struct pcmcia_device *p_dev, off_t where, u8 val)
{
        return pcmcia_access_config(p_dev, where, &val, pcmcia_write_cis_mem);
}
EXPORT_SYMBOL(pcmcia_write_config_byte);


/**
 * pcmcia_map_mem_page() - modify iomem window to point to a different offset
 * @p_dev: pcmcia device
 * @res: iomem resource already enabled by pcmcia_request_window()
 * @offset: card_offset to map
 *
 * pcmcia_map_mem_page() modifies what can be read and written by accessing
 * an iomem range previously enabled by pcmcia_request_window(), by setting
 * the card_offset value to @offset.
 */
int pcmcia_map_mem_page(struct pcmcia_device *p_dev, struct resource *res,
                        unsigned int offset)
{
        struct pcmcia_socket *s = p_dev->socket;
        unsigned int w;
        int ret;

        w = ((res->flags & IORESOURCE_BITS & WIN_FLAGS_REQ) >> 2) - 1;
        if (w >= MAX_WIN)
                return -EINVAL;

        mutex_lock(&s->ops_mutex);
        s->win[w].card_start = offset;
        ret = s->ops->set_mem_map(s, &s->win[w]);
        if (ret)
                dev_warn(&p_dev->dev, "failed to set_mem_map\n");
        mutex_unlock(&s->ops_mutex);
        return ret;
}
EXPORT_SYMBOL(pcmcia_map_mem_page);


/**
 * pcmcia_fixup_iowidth() - reduce io width to 8bit
 * @p_dev: pcmcia device
 *
 * pcmcia_fixup_iowidth() allows a PCMCIA device driver to reduce the
 * IO width to 8bit after having called pcmcia_enable_device()
 * previously.
 */
int pcmcia_fixup_iowidth(struct pcmcia_device *p_dev)
{
        struct pcmcia_socket *s = p_dev->socket;
        pccard_io_map io_off = { 0, 0, 0, 0, 1 };
        pccard_io_map io_on;
        int i, ret = 0;

        mutex_lock(&s->ops_mutex);

        dev_dbg(&p_dev->dev, "fixup iowidth to 8bit\n");

        if (!(s->state & SOCKET_PRESENT) ||
                !(p_dev->function_config->state & CONFIG_LOCKED)) {
                dev_dbg(&p_dev->dev, "No card? Config not locked?\n");
                ret = -EACCES;
                goto unlock;
        }

        io_on.speed = io_speed;
        for (i = 0; i < MAX_IO_WIN; i++) {
                if (!s->io[i].res)
                        continue;
                io_off.map = i;
                io_on.map = i;

                io_on.flags = MAP_ACTIVE | IO_DATA_PATH_WIDTH_8;
                io_on.start = s->io[i].res->start;
                io_on.stop = s->io[i].res->end;

                s->ops->set_io_map(s, &io_off);
                mdelay(40);
                s->ops->set_io_map(s, &io_on);
        }
unlock:
        mutex_unlock(&s->ops_mutex);

        return ret;
}
EXPORT_SYMBOL(pcmcia_fixup_iowidth);


/**
 * pcmcia_fixup_vpp() - set Vpp to a new voltage level
 * @p_dev: pcmcia device
 * @new_vpp: new Vpp voltage
 *
 * pcmcia_fixup_vpp() allows a PCMCIA device driver to set Vpp to
 * a new voltage level between calls to pcmcia_enable_device()
 * and pcmcia_disable_device().
 */
int pcmcia_fixup_vpp(struct pcmcia_device *p_dev, unsigned char new_vpp)
{
        struct pcmcia_socket *s = p_dev->socket;
        int ret = 0;

        mutex_lock(&s->ops_mutex);

        dev_dbg(&p_dev->dev, "fixup Vpp to %d\n", new_vpp);

        if (!(s->state & SOCKET_PRESENT) ||
                !(p_dev->function_config->state & CONFIG_LOCKED)) {
                dev_dbg(&p_dev->dev, "No card? Config not locked?\n");
                ret = -EACCES;
                goto unlock;
        }

        s->socket.Vpp = new_vpp;
        if (s->ops->set_socket(s, &s->socket)) {
                dev_warn(&p_dev->dev, "Unable to set VPP\n");
                ret = -EIO;
                goto unlock;
        }
        p_dev->vpp = new_vpp;

unlock:
        mutex_unlock(&s->ops_mutex);

        return ret;
}
EXPORT_SYMBOL(pcmcia_fixup_vpp);


/**
 * pcmcia_release_configuration() - physically disable a PCMCIA device
 * @p_dev: pcmcia device
 *
 * pcmcia_release_configuration() is the 1:1 counterpart to
 * pcmcia_enable_device(): If a PCMCIA device is no longer used by any
 * driver, the Vpp voltage is set to 0, IRQs will no longer be generated,
 * and I/O ranges will be disabled. As pcmcia_release_io() and
 * pcmcia_release_window() still need to be called, device drivers are
 * expected to call pcmcia_disable_device() instead.
 */
int pcmcia_release_configuration(struct pcmcia_device *p_dev)
{
        pccard_io_map io = { 0, 0, 0, 0, 1 };
        struct pcmcia_socket *s = p_dev->socket;
        config_t *c;
        int i;

        mutex_lock(&s->ops_mutex);
        c = p_dev->function_config;
        if (p_dev->_locked) {
                p_dev->_locked = 0;
                if (--(s->lock_count) == 0) {
                        s->socket.flags = SS_OUTPUT_ENA; /* Is this correct? */
                        s->socket.Vpp = 0;
                        s->socket.io_irq = 0;
                        s->ops->set_socket(s, &s->socket);
                }
        }
        if (c->state & CONFIG_LOCKED) {
                c->state &= ~CONFIG_LOCKED;
                if (c->state & CONFIG_IO_REQ)
                        for (i = 0; i < MAX_IO_WIN; i++) {
                                if (!s->io[i].res)
                                        continue;
                                s->io[i].Config--;
                                if (s->io[i].Config != 0)
                                        continue;
                                io.map = i;
                                s->ops->set_io_map(s, &io);
                        }
        }
        mutex_unlock(&s->ops_mutex);

        return 0;
}


/**
 * pcmcia_release_io() - release I/O allocated by a PCMCIA device
 * @p_dev: pcmcia device
 *
 * pcmcia_release_io() releases the I/O ranges allocated by a PCMCIA
 * device.  This may be invoked some time after a card ejection has
 * already dumped the actual socket configuration, so if the client is
 * "stale", we don't bother checking the port ranges against the
 * current socket values.
 */
static int pcmcia_release_io(struct pcmcia_device *p_dev)
{
        struct pcmcia_socket *s = p_dev->socket;
        int ret = -EINVAL;
        config_t *c;

        mutex_lock(&s->ops_mutex);
        if (!p_dev->_io)
                goto out;

        c = p_dev->function_config;

        release_io_space(s, &c->io[0]);

        if (c->io[1].end)
                release_io_space(s, &c->io[1]);

        p_dev->_io = 0;
        c->state &= ~CONFIG_IO_REQ;

out:
        mutex_unlock(&s->ops_mutex);

        return ret;
} /* pcmcia_release_io */


/**
 * pcmcia_release_window() - release reserved iomem for PCMCIA devices
 * @p_dev: pcmcia device
 * @res: iomem resource to release
 *
 * pcmcia_release_window() releases &struct resource *res which was
 * previously reserved by calling pcmcia_request_window().
 */
int pcmcia_release_window(struct pcmcia_device *p_dev, struct resource *res)
{
        struct pcmcia_socket *s = p_dev->socket;
        pccard_mem_map *win;
        unsigned int w;

        dev_dbg(&p_dev->dev, "releasing window %pR\n", res);

        w = ((res->flags & IORESOURCE_BITS & WIN_FLAGS_REQ) >> 2) - 1;
        if (w >= MAX_WIN)
                return -EINVAL;

        mutex_lock(&s->ops_mutex);
        win = &s->win[w];

        if (!(p_dev->_win & CLIENT_WIN_REQ(w))) {
                dev_dbg(&p_dev->dev, "not releasing unknown window\n");
                mutex_unlock(&s->ops_mutex);
                return -EINVAL;
        }

        /* Shut down memory window */
        win->flags &= ~MAP_ACTIVE;
        s->ops->set_mem_map(s, win);
        s->state &= ~SOCKET_WIN_REQ(w);

        /* Release system memory */
        if (win->res) {
                release_resource(res);
                release_resource(win->res);
                kfree(win->res);
                win->res = NULL;
        }
        res->start = res->end = 0;
        res->flags = IORESOURCE_MEM;
        p_dev->_win &= ~CLIENT_WIN_REQ(w);
        mutex_unlock(&s->ops_mutex);

        return 0;
} /* pcmcia_release_window */
EXPORT_SYMBOL(pcmcia_release_window);


/**
 * pcmcia_enable_device() - set up and activate a PCMCIA device
 * @p_dev: the associated PCMCIA device
 *
 * pcmcia_enable_device() physically enables a PCMCIA device. It parses
 * the flags passed to in @flags and stored in @p_dev->flags and sets up
 * the Vpp voltage, enables the speaker line, I/O ports and store proper
 * values to configuration registers.
 */
int pcmcia_enable_device(struct pcmcia_device *p_dev)
{
        int i;
        unsigned int base;
        struct pcmcia_socket *s = p_dev->socket;
        config_t *c;
        pccard_io_map iomap;
        unsigned char status = 0;
        unsigned char ext_status = 0;
        unsigned char option = 0;
        unsigned int flags = p_dev->config_flags;

        if (!(s->state & SOCKET_PRESENT))
                return -ENODEV;

        mutex_lock(&s->ops_mutex);
        c = p_dev->function_config;
        if (c->state & CONFIG_LOCKED) {
                mutex_unlock(&s->ops_mutex);
                dev_dbg(&p_dev->dev, "Configuration is locked\n");
                return -EACCES;
        }

        /* Do power control.  We don't allow changes in Vcc. */
        s->socket.Vpp = p_dev->vpp;
        if (s->ops->set_socket(s, &s->socket)) {
                mutex_unlock(&s->ops_mutex);
                dev_printk(KERN_WARNING, &p_dev->dev,
                           "Unable to set socket state\n");
                return -EINVAL;
        }

        /* Pick memory or I/O card, DMA mode, interrupt */
        if (p_dev->_io || flags & CONF_ENABLE_IRQ)
                flags |= CONF_ENABLE_IOCARD;
        if (flags & CONF_ENABLE_IOCARD)
                s->socket.flags |= SS_IOCARD;
        if (flags & CONF_ENABLE_SPKR) {
                s->socket.flags |= SS_SPKR_ENA;
                status = CCSR_AUDIO_ENA;
                if (!(p_dev->config_regs & PRESENT_STATUS))
                        dev_warn(&p_dev->dev, "speaker requested, but "
                                              "PRESENT_STATUS not set!\n");
        }
        if (flags & CONF_ENABLE_IRQ)
                s->socket.io_irq = s->pcmcia_irq;
        else
                s->socket.io_irq = 0;
        if (flags & CONF_ENABLE_ESR) {
                p_dev->config_regs |= PRESENT_EXT_STATUS;
                ext_status = ESR_REQ_ATTN_ENA;
        }
        s->ops->set_socket(s, &s->socket);
        s->lock_count++;

        dev_dbg(&p_dev->dev,
                "enable_device: V %d, flags %x, base %x, regs %x, idx %x\n",
                p_dev->vpp, flags, p_dev->config_base, p_dev->config_regs,
                p_dev->config_index);

        /* Set up CIS configuration registers */
        base = p_dev->config_base;
        if (p_dev->config_regs & PRESENT_COPY) {
                u16 tmp = 0;
                dev_dbg(&p_dev->dev, "clearing CISREG_SCR\n");
                pcmcia_write_cis_mem(s, 1, (base + CISREG_SCR)>>1, 1, &tmp);
        }
        if (p_dev->config_regs & PRESENT_PIN_REPLACE) {
                u16 tmp = 0;
                dev_dbg(&p_dev->dev, "clearing CISREG_PRR\n");
                pcmcia_write_cis_mem(s, 1, (base + CISREG_PRR)>>1, 1, &tmp);
        }
        if (p_dev->config_regs & PRESENT_OPTION) {
                if (s->functions == 1) {
                        option = p_dev->config_index & COR_CONFIG_MASK;
                } else {
                        option = p_dev->config_index & COR_MFC_CONFIG_MASK;
                        option |= COR_FUNC_ENA|COR_IREQ_ENA;
                        if (p_dev->config_regs & PRESENT_IOBASE_0)
                                option |= COR_ADDR_DECODE;
                }
                if ((flags & CONF_ENABLE_IRQ) &&
                        !(flags & CONF_ENABLE_PULSE_IRQ))
                        option |= COR_LEVEL_REQ;
                pcmcia_write_cis_mem(s, 1, (base + CISREG_COR)>>1, 1, &option);
                mdelay(40);
        }
        if (p_dev->config_regs & PRESENT_STATUS)
                pcmcia_write_cis_mem(s, 1, (base + CISREG_CCSR)>>1, 1, &status);

        if (p_dev->config_regs & PRESENT_EXT_STATUS)
                pcmcia_write_cis_mem(s, 1, (base + CISREG_ESR)>>1, 1,
                                        &ext_status);

        if (p_dev->config_regs & PRESENT_IOBASE_0) {
                u8 b = c->io[0].start & 0xff;
                pcmcia_write_cis_mem(s, 1, (base + CISREG_IOBASE_0)>>1, 1, &b);
                b = (c->io[0].start >> 8) & 0xff;
                pcmcia_write_cis_mem(s, 1, (base + CISREG_IOBASE_1)>>1, 1, &b);
        }
        if (p_dev->config_regs & PRESENT_IOSIZE) {
                u8 b = resource_size(&c->io[0]) + resource_size(&c->io[1]) - 1;
                pcmcia_write_cis_mem(s, 1, (base + CISREG_IOSIZE)>>1, 1, &b);
        }

        /* Configure I/O windows */
        if (c->state & CONFIG_IO_REQ) {
                iomap.speed = io_speed;
                for (i = 0; i < MAX_IO_WIN; i++)
                        if (s->io[i].res) {
                                iomap.map = i;
                                iomap.flags = MAP_ACTIVE;
                                switch (s->io[i].res->flags & IO_DATA_PATH_WIDTH) {
                                case IO_DATA_PATH_WIDTH_16:
                                        iomap.flags |= MAP_16BIT; break;
                                case IO_DATA_PATH_WIDTH_AUTO:
                                        iomap.flags |= MAP_AUTOSZ; break;
                                default:
                                        break;
                                }
                                iomap.start = s->io[i].res->start;
                                iomap.stop = s->io[i].res->end;
                                s->ops->set_io_map(s, &iomap);
                                s->io[i].Config++;
                        }
        }

        c->state |= CONFIG_LOCKED;
        p_dev->_locked = 1;
        mutex_unlock(&s->ops_mutex);
        return 0;
} /* pcmcia_enable_device */
EXPORT_SYMBOL(pcmcia_enable_device);


/**
 * pcmcia_request_io() - attempt to reserve port ranges for PCMCIA devices
 * @p_dev: the associated PCMCIA device
 *
 * pcmcia_request_io() attempts to reserve the IO port ranges specified in
 * &struct pcmcia_device @p_dev->resource[0] and @p_dev->resource[1]. The
 * "start" value is the requested start of the IO port resource; "end"
 * reflects the number of ports requested. The number of IO lines requested
 * is specified in &struct pcmcia_device @p_dev->io_lines.
 */
int pcmcia_request_io(struct pcmcia_device *p_dev)
{
        struct pcmcia_socket *s = p_dev->socket;
        config_t *c = p_dev->function_config;
        int ret = -EINVAL;

        mutex_lock(&s->ops_mutex);
        dev_dbg(&p_dev->dev, "pcmcia_request_io: %pR , %pR",
                &c->io[0], &c->io[1]);

        if (!(s->state & SOCKET_PRESENT)) {
                dev_dbg(&p_dev->dev, "pcmcia_request_io: No card present\n");
                goto out;
        }

        if (c->state & CONFIG_LOCKED) {
                dev_dbg(&p_dev->dev, "Configuration is locked\n");
                goto out;
        }
        if (c->state & CONFIG_IO_REQ) {
                dev_dbg(&p_dev->dev, "IO already configured\n");
                goto out;
        }

        ret = alloc_io_space(s, &c->io[0], p_dev->io_lines);
        if (ret)
                goto out;

        if (c->io[1].end) {
                ret = alloc_io_space(s, &c->io[1], p_dev->io_lines);
                if (ret) {
                        struct resource tmp = c->io[0];
                        /* release the previously allocated resource */
                        release_io_space(s, &c->io[0]);
                        /* but preserve the settings, for they worked... */
                        c->io[0].end = resource_size(&tmp);
                        c->io[0].start = tmp.start;
                        c->io[0].flags = tmp.flags;
                        goto out;
                }
        } else
                c->io[1].start = 0;

        c->state |= CONFIG_IO_REQ;
        p_dev->_io = 1;

        dev_dbg(&p_dev->dev, "pcmcia_request_io succeeded: %pR , %pR",
                &c->io[0], &c->io[1]);
out:
        mutex_unlock(&s->ops_mutex);

        return ret;
} /* pcmcia_request_io */
EXPORT_SYMBOL(pcmcia_request_io);


/**
 * pcmcia_request_irq() - attempt to request a IRQ for a PCMCIA device
 * @p_dev: the associated PCMCIA device
 * @handler: IRQ handler to register
 *
 * pcmcia_request_irq() is a wrapper around request_irq() which allows
 * the PCMCIA core to clean up the registration in pcmcia_disable_device().
 * Drivers are free to use request_irq() directly, but then they need to
 * call free_irq() themselfves, too. Also, only %IRQF_SHARED capable IRQ
 * handlers are allowed.
 */
int __must_check pcmcia_request_irq(struct pcmcia_device *p_dev,
                                    irq_handler_t handler)
{
        int ret;

        if (!p_dev->irq)
                return -EINVAL;

        ret = request_irq(p_dev->irq, handler, IRQF_SHARED,
                        p_dev->devname, p_dev->priv);
        if (!ret)
                p_dev->_irq = 1;

        return ret;
}
EXPORT_SYMBOL(pcmcia_request_irq);


/**
 * pcmcia_request_exclusive_irq() - attempt to request an exclusive IRQ first
 * @p_dev: the associated PCMCIA device
 * @handler: IRQ handler to register
 *
 * pcmcia_request_exclusive_irq() is a wrapper around request_irq() which
 * attempts first to request an exclusive IRQ. If it fails, it also accepts
 * a shared IRQ, but prints out a warning. PCMCIA drivers should allow for
 * IRQ sharing and either use request_irq directly (then they need to call
 * free_irq() themselves, too), or the pcmcia_request_irq() function.
 */
int __must_check
__pcmcia_request_exclusive_irq(struct pcmcia_device *p_dev,
                        irq_handler_t handler)
{
        int ret;

        if (!p_dev->irq)
                return -EINVAL;

        ret = request_irq(p_dev->irq, handler, 0, p_dev->devname, p_dev->priv);
        if (ret) {
                ret = pcmcia_request_irq(p_dev, handler);
                dev_printk(KERN_WARNING, &p_dev->dev, "pcmcia: "
                        "request for exclusive IRQ could not be fulfilled.\n");
                dev_printk(KERN_WARNING, &p_dev->dev, "pcmcia: the driver "
                        "needs updating to supported shared IRQ lines.\n");
        }
        if (ret)
                dev_printk(KERN_INFO, &p_dev->dev, "request_irq() failed\n");
        else
                p_dev->_irq = 1;

        return ret;
} /* pcmcia_request_exclusive_irq */
EXPORT_SYMBOL(__pcmcia_request_exclusive_irq);


#ifdef CONFIG_PCMCIA_PROBE

/* mask of IRQs already reserved by other cards, we should avoid using them */
static u8 pcmcia_used_irq[32];

static irqreturn_t test_action(int cpl, void *dev_id)
{
        return IRQ_NONE;
}

/**
 * pcmcia_setup_isa_irq() - determine whether an ISA IRQ can be used
 * @p_dev - the associated PCMCIA device
 *
 * locking note: must be called with ops_mutex locked.
 */
static int pcmcia_setup_isa_irq(struct pcmcia_device *p_dev, int type)
{
        struct pcmcia_socket *s = p_dev->socket;
        unsigned int try, irq;
        u32 mask = s->irq_mask;
        int ret = -ENODEV;

        for (try = 0; try < 64; try++) {
                irq = try % 32;

                if (irq > NR_IRQS)
                        continue;

                /* marked as available by driver, not blocked by userspace? */
                if (!((mask >> irq) & 1))
                        continue;

                /* avoid an IRQ which is already used by another PCMCIA card */
                if ((try < 32) && pcmcia_used_irq[irq])
                        continue;

                /* register the correct driver, if possible, to check whether
                 * registering a dummy handle works, i.e. if the IRQ isn't
                 * marked as used by the kernel resource management core */
                ret = request_irq(irq, test_action, type, p_dev->devname,
                                  p_dev);
                if (!ret) {
                        free_irq(irq, p_dev);
                        p_dev->irq = s->pcmcia_irq = irq;
                        pcmcia_used_irq[irq]++;
                        break;
                }
        }

        return ret;
}

void pcmcia_cleanup_irq(struct pcmcia_socket *s)
{
        pcmcia_used_irq[s->pcmcia_irq]--;
        s->pcmcia_irq = 0;
}

#else /* CONFIG_PCMCIA_PROBE */

static int pcmcia_setup_isa_irq(struct pcmcia_device *p_dev, int type)
{
        return -EINVAL;
}

void pcmcia_cleanup_irq(struct pcmcia_socket *s)
{
        s->pcmcia_irq = 0;
        return;
}

#endif  /* CONFIG_PCMCIA_PROBE */


/**
 * pcmcia_setup_irq() - determine IRQ to be used for device
 * @p_dev - the associated PCMCIA device
 *
 * locking note: must be called with ops_mutex locked.
 */
int pcmcia_setup_irq(struct pcmcia_device *p_dev)
{
        struct pcmcia_socket *s = p_dev->socket;

        if (p_dev->irq)
                return 0;

        /* already assigned? */
        if (s->pcmcia_irq) {
                p_dev->irq = s->pcmcia_irq;
                return 0;
        }

        /* prefer an exclusive ISA irq */
        if (!pcmcia_setup_isa_irq(p_dev, 0))
                return 0;

        /* but accept a shared ISA irq */
        if (!pcmcia_setup_isa_irq(p_dev, IRQF_SHARED))
                return 0;

        /* but use the PCI irq otherwise */
        if (s->pci_irq) {
                p_dev->irq = s->pcmcia_irq = s->pci_irq;
                return 0;
        }

        return -EINVAL;
}


/**
 * pcmcia_request_window() - attempt to reserve iomem for PCMCIA devices
 * @p_dev: the associated PCMCIA device
 * @res: &struct resource pointing to p_dev->resource[2..5]
 * @speed: access speed
 *
 * pcmcia_request_window() attepts to reserve an iomem ranges specified in
 * &struct resource @res pointing to one of the entries in
 * &struct pcmcia_device @p_dev->resource[2..5]. The "start" value is the
 * requested start of the IO mem resource; "end" reflects the size
 * requested.
 */
int pcmcia_request_window(struct pcmcia_device *p_dev, struct resource *res,
                        unsigned int speed)
{
        struct pcmcia_socket *s = p_dev->socket;
        pccard_mem_map *win;
        u_long align;
        int w;

        dev_dbg(&p_dev->dev, "request_window %pR %d\n", res, speed);

        if (!(s->state & SOCKET_PRESENT)) {
                dev_dbg(&p_dev->dev, "No card present\n");
                return -ENODEV;
        }

        /* Window size defaults to smallest available */
        if (res->end == 0)
                res->end = s->map_size;
        align = (s->features & SS_CAP_MEM_ALIGN) ? res->end : s->map_size;
        if (res->end & (s->map_size-1)) {
                dev_dbg(&p_dev->dev, "invalid map size\n");
                return -EINVAL;
        }
        if ((res->start && (s->features & SS_CAP_STATIC_MAP)) ||
            (res->start & (align-1))) {
                dev_dbg(&p_dev->dev, "invalid base address\n");
                return -EINVAL;
        }
        if (res->start)
                align = 0;

        /* Allocate system memory window */
        mutex_lock(&s->ops_mutex);
        for (w = 0; w < MAX_WIN; w++)
                if (!(s->state & SOCKET_WIN_REQ(w)))
                        break;
        if (w == MAX_WIN) {
                dev_dbg(&p_dev->dev, "all windows are used already\n");
                mutex_unlock(&s->ops_mutex);
                return -EINVAL;
        }

        win = &s->win[w];

        if (!(s->features & SS_CAP_STATIC_MAP)) {
                win->res = pcmcia_find_mem_region(res->start, res->end, align,
                                                0, s);
                if (!win->res) {
                        dev_dbg(&p_dev->dev, "allocating mem region failed\n");
                        mutex_unlock(&s->ops_mutex);
                        return -EINVAL;
                }
        }
        p_dev->_win |= CLIENT_WIN_REQ(w);

        /* Configure the socket controller */
        win->map = w+1;
        win->flags = res->flags & WIN_FLAGS_MAP;
        win->speed = speed;
        win->card_start = 0;

        if (s->ops->set_mem_map(s, win) != 0) {
                dev_dbg(&p_dev->dev, "failed to set memory mapping\n");
                mutex_unlock(&s->ops_mutex);
                return -EIO;
        }
        s->state |= SOCKET_WIN_REQ(w);

        /* Return window handle */
        if (s->features & SS_CAP_STATIC_MAP)
                res->start = win->static_start;
        else
                res->start = win->res->start;

        /* convert to new-style resources */
        res->end += res->start - 1;
        res->flags &= ~WIN_FLAGS_REQ;
        res->flags |= (win->map << 2) | IORESOURCE_MEM;
        res->parent = win->res;
        if (win->res)
                request_resource(&iomem_resource, res);

        dev_dbg(&p_dev->dev, "request_window results in %pR\n", res);

        mutex_unlock(&s->ops_mutex);

        return 0;
} /* pcmcia_request_window */
EXPORT_SYMBOL(pcmcia_request_window);


/**
 * pcmcia_disable_device() - disable and clean up a PCMCIA device
 * @p_dev: the associated PCMCIA device
 *
 * pcmcia_disable_device() is the driver-callable counterpart to
 * pcmcia_enable_device(): If a PCMCIA device is no longer used,
 * drivers are expected to clean up and disable the device by calling
 * this function. Any I/O ranges (iomem and ioports) will be released,
 * the Vpp voltage will be set to 0, and IRQs will no longer be
 * generated -- at least if there is no other card function (of
 * multifunction devices) being used.
 */
void pcmcia_disable_device(struct pcmcia_device *p_dev)
{
        int i;

        dev_dbg(&p_dev->dev, "disabling device\n");

        for (i = 0; i < MAX_WIN; i++) {
                struct resource *res = p_dev->resource[MAX_IO_WIN + i];
                if (res->flags & WIN_FLAGS_REQ)
                        pcmcia_release_window(p_dev, res);
        }

        pcmcia_release_configuration(p_dev);
        pcmcia_release_io(p_dev);
        if (p_dev->_irq) {
                free_irq(p_dev->irq, p_dev->priv);
                p_dev->_irq = 0;
        }
}
EXPORT_SYMBOL(pcmcia_disable_device);