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ISA Plug & Play support by Jaroslav Kysela 

==========================================================

Interface /proc/isapnp

======================

Read commands:

--------------

No comment.

Write commands:

---------------

With the write interface you can activate or modify the configuration of

ISA Plug & Play devices.  It is mainly useful for drivers which have not

been rewritten to use the ISA Plug & Play kernel support yet.

card    - select PnP device by vendor identification

csn             - select PnP device by CSN

dev     - select logical device

auto                    - run autoconfigure

activate                - activate logical device

deactivate              - deactivate logical device

port    - set port 0-7 to value

irq     - set IRQ 0-1 to value

dma     - set DMA 0-1 to value

memory          - set memory 0-3 to value

poke    - poke configuration byte to selected register

pokew   - poke configuration word to selected register

poked   - poke configuration dword to selected register

allow_dma0      - allow dma channel 0 during auto activation: 0=off, 1=on

Explanation:

        - variable  begins with zero

        - variable  begins with one

        -  is in the standard format 'ABC1234'

        -  is in the standard format 'ABC1234'

Example:

cat > /proc/isapnp <

card 0 CSC7537

dev 0 CSC0000

port 0 0x534

port 1 0x388

port 2 0x220

irq 0 5

dma 0 1

dma 1 3

poke 0x70 9

activate

logdev 0 CSC0001

port 0 0x240

activate

EOF

Information for developers

==========================

Finding a device

----------------

extern struct pci_bus *isapnp_find_card(unsigned short vendor,

                                        unsigned short device,

                                        struct pci_bus *from);

This function finds an ISA PnP card.  For the vendor argument, the

ISAPNP_VENDOR(a,b,c) macro should be used, where a,b,c are characters or

integers.  For the device argument the ISAPNP_DEVICE(x) macro should be

used, where x is an integer value.  Both vendor and device arguments

can be taken from contents of the /proc/isapnp file.

extern struct pci_dev *isapnp_find_dev(struct pci_bus *card,

                                       unsigned short vendor,

                                       unsigned short function,

                                       struct pci_dev *from);

This function finds an ISA PnP device. If card is NULL, then the global

search mode is used (all devices are used for the searching).  Otherwise

only devices which belong to the specified card are checked.  For the

function number the ISAPNP_FUNCTION(x) macro can be used; it works

similarly to the ISAPNP_DEVICE(x) macro.

extern int isapnp_probe_cards(const struct isapnp_card_id *ids,

                              int (*probe)(struct pci_bus *card,

                              const struct isapnp_card_id *id));

This function is a helper for drivers which need to use more than

one device from an ISA PnP card.  The probe callback is called with

appropriate arguments for each card.

Example for ids parameter initialization:

static struct isapnp_card_id card_ids[] __devinitdata = {

        {

                ISAPNP_CARD_ID('A','D','V', 0x550a),

                devs: {

                        ISAPNP_DEVICE_ID('A', 'D', 'V', 0x0010),

                        ISAPNP_DEVICE_ID('A', 'D', 'V', 0x0011)

                },

                driver_data: 0x1234,

        },

        {

                ISAPNP_CARD_END,

        }

};

ISAPNP_CARD_TABLE(card_ids);

extern int isapnp_probe_devs(const struct isapnp_device_id *ids,

                             int (*probe)(struct pci_bus *card,

                             const struct isapnp_device_id *id));

This function is a helper for drivers which need to use one

device from an ISA PnP card.  The probe callback is called with

appropriate arguments for each matched device.

Example for ids parameter initialization:

static struct isapnp_device_id device_ids[] __devinitdata = {

        { ISAPNP_DEVICE_SINGLE('E','S','S', 0x0968, 'E','S','S', 0x0968), },

        { ISAPNP_DEVICE_SINGLE_END, }

};

MODULE_DEVICE_TABLE(isapnp, device_ids);

ISA PnP configuration

=====================

There are two ways in which the ISA PnP interface can be used.

First way: low-level

--------------------

All ISA PNP configuration registers are accessible via the low-level

isapnp_(read|write)_(byte|word|dword) functions.

The function isapnp_cfg_begin() must be called before any lowlevel function.

The function isapnp_cfg_end() must be always called after configuration

otherwise the access to the ISA PnP configuration functions will be blocked.

Second way: auto-configuration

------------------------------

This feature gives to the driver the real power of the ISA PnP driver.

The function dev->prepare() initializes the resource members in the device

structure.  This structure contains all resources set to auto configuration

values after the initialization.  The device driver may modify some resources

to skip the auto configuration for a given resource.

Once the device structure contains all requested resource values, the function

dev->activate() must be called to assign free resources to resource members

with the auto configuration value.

Function dev->activate() does:

   - resources with the auto configuration value are configured

   - the auto configuration is created using ISA PnP resource map

   - the function writes configuration to ISA PnP configuration registers

   - the function returns to the caller actual used resources

When the device driver is removed, function dev->deactivate() has to be

called to free all assigned resources.

Example (game port initialization)

==================================

/*** initialization ***/

        struct pci_dev *dev;

        /* find the first game port, use standard PnP IDs */

        dev = isapnp_find_dev(NULL,

                              ISAPNP_VENDOR('P','N','P'),

                              ISAPNP_FUNCTION(0xb02f),

                              NULL);

        if (!dev)

                return -ENODEV;

        if (dev->active)

                return -EBUSY;

        if (dev->prepare(dev)<0)

                return -EAGAIN;

        if (!(dev->resource[0].flags & IORESOURCE_IO))

                return -ENODEV;

        if (!dev->ro) {

                /* override resource */

                if (user_port != USER_PORT_AUTO_VALUE)

                        isapnp_resource_change(&dev->resource[0], user_port, 1);

        }

        if (dev->activate(dev)<0) {

                printk("isapnp configure failed (out of resources?)\n");

                return -ENOMEM;

        }

        user_port = dev->resource[0].start;             /* get real port */

/*** deactivation ***/

        /* to deactivate use: */

        if (dev)

                dev->deactivate(dev);