Manual browser: pcmcia_io_alloc(9)

PCMCIA(9) Kernel Developer's Manual PCMCIA(9)


PCMCIA pcmcia_function_init, pcmcia_function_enable, pcmcia_function_disable, pcmcia_io_alloc, pcmcia_io_free, pcmcia_io_map, pcmcia_io_unmap, pcmcia_mem_alloc, pcmcia_mem_free, pcmcia_mem_map, pcmcia_mem_unmap, pcmcia_intr_establish, pcmcia_intr_disestablish, pcmcia_cis_read_1, pcmcia_cis_read_2, pcmcia_cis_read_3, pcmcia_cis_read_4, pcmcia_cis_read_n, pcmcia_scan_cissupport for PCMCIA PC-Card devices


#include <sys/bus.h>
#include <dev/pcmcia/pcmciareg.h>
#include <dev/pcmcia/pcmciavar.h>
#include <dev/pcmcia/pcmciadevs.h>

pcmcia_function_init(struct pcmcia_function *pf, struct pcmcia_config_entry *cfe);

pcmcia_function_enable(struct pcmcia_function *pf);

pcmcia_function_disable(struct pcmcia_function *pf);

pcmcia_io_alloc(struct pcmcia_function *pf, bus_addr_t start, bus_size_t size, bus_size_t align, struct pcmcia_io_handle *pciop);

pcmcia_io_free(struct pcmcia_function *pf, struct pcmcia_io_handle *pcihp);

pcmcia_io_map(struct pcmcia_function *pf, int width, struct pcmcia_io_handle *pcihp, int *windowp);

pcmcia_io_unmap(struct pcmcia_function *pf, int window);

pcmcia_mem_alloc(struct pcmcia_function *pf, bus_size_t size, struct pcmcia_mem_handle *pcmhp);

pcmcia_mem_free(struct pcmcia_function *pf, struct pcmcia_mem_handle *pcmhp);

pcmcia_mem_map(struct pcmcia_function *pf, int width, bus_addr_t card_addr, bus_size_t size, struct pcmcia_mem_handle *pcmhp, bus_size_t *offsetp, int *windowp);

pcmcia_mem_unmap(struct pcmcia_function *pf, int window);

void *
pcmcia_intr_establish(struct pcmcia_function *pf, int level, int (*handler)(void *), void *arg);

pcmcia_intr_disestablish(struct pcmcia_function *pf, void *ih);

pcmcia_cis_read_1(struct pcmcia_tuple *tuple, int index);

pcmcia_cis_read_2(struct pcmcia_tuple *tuple, int index);

pcmcia_cis_read_3(struct pcmcia_tuple *tuple, int index);

pcmcia_cis_read_4(struct pcmcia_tuple *tuple, int index);

pcmcia_cis_read_n(struct pcmcia_tuple *tuple, int number, int index);

pcmcia_scan_cis(struct device *dev, int (*func)(struct pcmcia_tuple *, void *), void *arg);


The machine-independent PCMCIA subsystem provides support for PC-Card devices defined by the Personal Computer Memory Card International Assocation (PCMCIA). The PCMCIA bus supports insertion and removal of cards while a system is powered-on (ie, dynamic reconfiguration). The socket must be powered-off when a card is not present. To the user, this appears as though the socket is "hot" during insertion and removal events.

A PCMCIA controller interfaces the PCMCIA bus with the ISA or PCI busses on the host system. The controller is responsible for detecting and enabling devices and for allocating and mapping resources such as memory and interrupts to devices on the PCMCIA bus.

Each device has a table called the Card Information Structure (CIS) which contains configuration information. The tuples in the CIS are used by the controller to uniquely identify the device. Additional information may be present in the CIS, such as the ethernet MAC address, that can be accessed and used within a device driver.

Devices on the PCMCIA bus are uniquely identified by a 32-bit manufacturer ID and a 32-bit product ID. Additionally, devices can perform multiple functions (such as ethernet and modem) and these functions are identified by a function ID.

PCMCIA devices do not support DMA, however memory on the device can be mapped into the address space of the host.


Drivers attached to the PCMCIA bus will make use of the following data types:
struct pcmcia_card
Devices (cards) have their identity recorded in this structure. It contains the following members:

	char		*cis1_info[4]; 
        int32_t         manufacturer; 
        int32_t         product; 
        uint16_t       error; 
        SIMPLEQ_HEAD(, pcmcia_function)	pf_head;
struct pcmcia_function
Identifies the function of the devices. A device can have multiple functions. Consider it an opaque type for identifying a particular function of a device.
struct pcmcia_config_entry
Contains information about the resources requested by the device. It contains the following members:

        int             number; 
        uint32_t       flags; 
        int     	iftype; 
        int   		num_iospace; 
        u_long 		iomask; 
        struct { 
                u_long  length; 
                u_long  start; 
        } iospace[4]; 
        uint16_t       irqmask; 
        int             num_memspace; 
        struct { 
                u_long  length; 
                u_long  cardaddr; 
                u_long  hostaddr; 
        } 		memspace[2]; 
        int             maxtwins; 
	SIMPLEQ_ENTRY(pcmcia_config_entry) cfe_list;
struct pcmcia_tuple
A handle for identifying an entry in the CIS.
struct pcmcia_io_handle
A handle for mapping and allocating I/O address spaces. It contains the tag and handle for accessing the bus-space.
struct pcmcia_mem_handle
A handle for mapping and allocating memory address spaces. It contains the tag and handle for accessing the bus-space.
struct pcmcia_attach_args
A structure used to inform the driver of the device properties. It contains the following members:

	int32_t			manufacturer; 
	int32_t			product; 
	struct pcmcia_card	*card; 
	struct pcmcia_function	*pf;


pcmcia_function_init(pf, cfe)
Initialise the machine-independent PCMCIA state with the config entry cfe.
Provide power to the socket containing the device specified by device function pf.
Remove power from the socket containing the device specified by device function pf.
pcmcia_io_alloc(pf, start, size, align, pciop)
Request I/O space for device function pf at address start of size size. Alignment is specified by align. A handle for the I/O space is returned in pciop.
pcmcia_io_free(pf, pcihp)
Release I/O space with handle pcihp for device function pf.
pcmcia_io_map(pf, width, pcihp, windowp)
Map device I/O for device function pf to the I/O space with handle pcihp. The width of data access is specified by width. Valid values for the width are:
Use the largest I/O width reported by the device.
Force 8-bit I/O width.
Force 16-bit I/O width.

A handle for the mapped I/O window is returned in windowp.

pcmcia_io_unmap(pf, window)
Unmap the I/O window window for device function pf.
pcmcia_mem_alloc(pf, size, pcmhp)
Request memory space for device function pf of size size. A handle for the memory space is returned in pcmhp.
pcmcia_mem_free(pf, pcmhp)
Release memory space with handle pcmhp for device function pf.
pcmcia_mem_map(pf, width, card_addr, size, pcmhp, offsetp, windowp)
Map device memory for device function pf to the memory space with handle pcmhp. The address of the device memory starts at card_addr and is size size. The width of data access is specified by width. Valid values for the width are:
Force 8-bit memory width.
Force 16-bit memory width.

A handle for the mapped memory window is returned in windowp and a bus-space offset into the memory window is returned in offsetp.

pcmcia_mem_unmap(pf, window)
Unmap the memory window window for device function pf.
pcmcia_intr_establish(pf, level, handler, arg)
Establish an interrupt handler for device function pf. The priority of the interrupt is specified by level. When the interrupt occurs the function handler is called with argument arg. The return value is a handle for the interrupt handler. pcmcia_intr_establish() returns an opaque handle to an event descriptor if it succeeds, and returns NULL on failure.
pcmcia_intr_disestablish(pf, ih)
Dis-establish the interrupt handler for device function pf with handle ih. The handle was returned from pcmcia_intr_establish().
pcmcia_cis_read_1(tuple, index)
Read one byte from tuple tuple at index index in the CIS.
pcmcia_cis_read_2(tuple, index)
Read two bytes from tuple tuple at index index in the CIS.
pcmcia_cis_read_3(tuple, index)
Read three bytes from tuple tuple at index index in the CIS.
pcmcia_cis_read_4(tuple, index)
Read four bytes from tuple tuple at index index in the CIS.
pcmcia_cis_read_n(tuple, number, index)
Read n bytes from tuple tuple at index index in the CIS.
pcmcia_scan_cis(dev, func, arg)
Scan the CIS for device dev. For each tuple in the CIS, function func is called with the tuple and the argument arg. func should return 0 if the tuple it was called with is the one it was looking for, or 1 otherwise.


During autoconfiguration, a PCMCIA driver will receive a pointer to struct pcmcia_attach_args describing the device attached to the PCMCIA bus. Drivers match the device using the manufacturer and product members.

During the driver attach step, drivers will use the pcmcia function pf. The driver should traverse the list of config entries searching for a useful configuration. This config entry is passed to pcmcia_function_init() to initialise the machine-independent interface. I/O and memory resources should be initialised using pcmcia_io_alloc() and pcmcia_mem_alloc() using the specified resources in the config entry. These resources can then be mapped into processor bus space using pcmcia_io_map() and pcmcia_mem_map() respectively. Upon successful allocation of resources, power can be applied to the device with pcmcia_function_enable() so that device-specific interrogation can be performed. Finally, power should be removed from the device using pcmcia_function_disable().

Since PCMCIA devices support dynamic configuration, drivers should make use of pmf(9) framework. Power can be applied and the interrupt handler should be established through this interface.


PCMCIA devices do not support DMA.


The PCMCIA subsystem itself is implemented within the file sys/dev/pcmcia/pcmcia.c. The database of known devices exists within the file sys/dev/pcmcia/pcmciadevs_data.h and is generated automatically from the file sys/dev/pcmcia/pcmciadevs. New manufacturer and product identifiers should be added to this file. The database can be regenerated using the Makefile sys/dev/pcmcia/Makefile.pcmciadevs.


pcic(4), pcmcia(4), tcic(4), autoconf(9), bus_dma(9), bus_space(9), driver(9)

Personal Computer Memory Card International Association (PCMCIA), PC Card 95 Standard, 1995.


The machine-independent PCMCIA subsystem appeared in NetBSD 1.3.
April 15, 2010 NetBSD 7.0