FreeBSD/Linux Kernel Cross Reference
sys/Documentation/isapnp.txt

     ISA Plug & Play support by Jaroslav Kysela <perex@suse.cz>
     ==========================================================
     
     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 <idx> <vendor>     - select PnP device by vendor identification
    csn <CSN>               - select PnP device by CSN
    dev <idx> <logdev>      - select logical device
    auto                    - run autoconfigure
    activate                - activate logical device
    deactivate              - deactivate logical device
    port <idx> <value>      - set port 0-7 to value
    irq <idx> <value>       - set IRQ 0-1 to value
    dma <idx> <value>       - set DMA 0-1 to value
    memory <idx> <value>    - set memory 0-3 to value
    poke <reg> <value>      - poke configuration byte to selected register
    pokew <reg> <value>     - poke configuration word to selected register
    poked <reg> <value>     - poke configuration dword to selected register
    allow_dma0 <value>      - allow dma channel 0 during auto activation: 0=off, 1=on
    
    Explanation:
            - variable <idx> begins with zero
            - variable <CSN> begins with one
            - <vendor> is in the standard format 'ABC1234'
            - <logdev> is in the standard format 'ABC1234'
    
    Example:
    
    cat > /proc/isapnp <<EOF
    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);

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