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pnp.txt: standardize document format

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Each text file under Documentation follows a different
format. Some doesn't even have titles!

Change its representation to follow the adopted standard,
using ReST markups for it to be parseable by Sphinx:

- Use a markup for document title;
- use :Author: and :Last updated: for authorship;
- adjust whitespaces where needed;
- mark literal blocks;
- fix a few subtitle markups.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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Mauro Carvalho Chehab 2017-05-16 11:23:58 -03:00 committed by Jonathan Corbet
parent 5da98b8230
commit 9a4aa7bfce
1 changed files with 177 additions and 136 deletions
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Documentation/pnp.txt
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@ -1,98 +1,118 @@
=================================
Linux Plug and Play Documentation Linux Plug and Play Documentation
by Adam Belay <ambx1@neo.rr.com> =================================
last updated: Oct. 16, 2002
---------------------------------------------------------------------------------------
:Author: Adam Belay <ambx1@neo.rr.com>
:Last updated: Oct. 16, 2002
Overview Overview
-------- --------
Plug and Play provides a means of detecting and setting resources for legacy or
Plug and Play provides a means of detecting and setting resources for legacy or
otherwise unconfigurable devices. The Linux Plug and Play Layer provides these otherwise unconfigurable devices. The Linux Plug and Play Layer provides these
services to compatible drivers. services to compatible drivers.
The User Interface The User Interface
------------------ ------------------
The Linux Plug and Play user interface provides a means to activate PnP devices
The Linux Plug and Play user interface provides a means to activate PnP devices
for legacy and user level drivers that do not support Linux Plug and Play. The for legacy and user level drivers that do not support Linux Plug and Play. The
user interface is integrated into sysfs. user interface is integrated into sysfs.
In addition to the standard sysfs file the following are created in each In addition to the standard sysfs file the following are created in each
device's directory: device's directory:
id - displays a list of support EISA IDs - id - displays a list of support EISA IDs
options - displays possible resource configurations - options - displays possible resource configurations
resources - displays currently allocated resources and allows resource changes - resources - displays currently allocated resources and allows resource changes
-activating a device activating a device
^^^^^^^^^^^^^^^^^^^
#echo "auto" > resources ::
# echo "auto" > resources
this will invoke the automatic resource config system to activate the device this will invoke the automatic resource config system to activate the device
-manually activating a device manually activating a device
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#echo "manual <depnum> <mode>" > resources ::
<depnum> - the configuration number
<mode> - static or dynamic
static = for next boot
dynamic = now
-disabling a device # echo "manual <depnum> <mode>" > resources
#echo "disable" > resources <depnum> - the configuration number
<mode> - static or dynamic
static = for next boot
dynamic = now
disabling a device
^^^^^^^^^^^^^^^^^^
::
# echo "disable" > resources
EXAMPLE: EXAMPLE:
Suppose you need to activate the floppy disk controller. Suppose you need to activate the floppy disk controller.
1.) change to the proper directory, in my case it is
/driver/bus/pnp/devices/00:0f
# cd /driver/bus/pnp/devices/00:0f
# cat name
PC standard floppy disk controller
2.) check if the device is already active 1. change to the proper directory, in my case it is
# cat resources /driver/bus/pnp/devices/00:0f::
DISABLED
- Notice the string "DISABLED". This means the device is not active. # cd /driver/bus/pnp/devices/00:0f
# cat name
PC standard floppy disk controller
3.) check the device's possible configurations (optional) 2. check if the device is already active::
# cat options
Dependent: 01 - Priority acceptable
port 0x3f0-0x3f0, align 0x7, size 0x6, 16-bit address decoding
port 0x3f7-0x3f7, align 0x0, size 0x1, 16-bit address decoding
irq 6
dma 2 8-bit compatible
Dependent: 02 - Priority acceptable
port 0x370-0x370, align 0x7, size 0x6, 16-bit address decoding
port 0x377-0x377, align 0x0, size 0x1, 16-bit address decoding
irq 6
dma 2 8-bit compatible
4.) now activate the device # cat resources
# echo "auto" > resources DISABLED
5.) finally check if the device is active - Notice the string "DISABLED". This means the device is not active.
# cat resources
io 0x3f0-0x3f5
io 0x3f7-0x3f7
irq 6
dma 2
also there are a series of kernel parameters: 3. check the device's possible configurations (optional)::
pnp_reserve_irq=irq1[,irq2] ....
pnp_reserve_dma=dma1[,dma2] .... # cat options
pnp_reserve_io=io1,size1[,io2,size2] .... Dependent: 01 - Priority acceptable
pnp_reserve_mem=mem1,size1[,mem2,size2] .... port 0x3f0-0x3f0, align 0x7, size 0x6, 16-bit address decoding
port 0x3f7-0x3f7, align 0x0, size 0x1, 16-bit address decoding
irq 6
dma 2 8-bit compatible
Dependent: 02 - Priority acceptable
port 0x370-0x370, align 0x7, size 0x6, 16-bit address decoding
port 0x377-0x377, align 0x0, size 0x1, 16-bit address decoding
irq 6
dma 2 8-bit compatible
4. now activate the device::
# echo "auto" > resources
5. finally check if the device is active::
# cat resources
io 0x3f0-0x3f5
io 0x3f7-0x3f7
irq 6
dma 2
also there are a series of kernel parameters::
pnp_reserve_irq=irq1[,irq2] ....
pnp_reserve_dma=dma1[,dma2] ....
pnp_reserve_io=io1,size1[,io2,size2] ....
pnp_reserve_mem=mem1,size1[,mem2,size2] ....
The Unified Plug and Play Layer The Unified Plug and Play Layer
------------------------------- -------------------------------
All Plug and Play drivers, protocols, and services meet at a central location
All Plug and Play drivers, protocols, and services meet at a central location
called the Plug and Play Layer. This layer is responsible for the exchange of called the Plug and Play Layer. This layer is responsible for the exchange of
information between PnP drivers and PnP protocols. Thus it automatically information between PnP drivers and PnP protocols. Thus it automatically
forwards commands to the proper protocol. This makes writing PnP drivers forwards commands to the proper protocol. This makes writing PnP drivers
@ -101,64 +121,73 @@ significantly easier.
The following functions are available from the Plug and Play Layer: The following functions are available from the Plug and Play Layer:
pnp_get_protocol pnp_get_protocol
- increments the number of uses by one increments the number of uses by one
pnp_put_protocol pnp_put_protocol
- deincrements the number of uses by one deincrements the number of uses by one
pnp_register_protocol pnp_register_protocol
- use this to register a new PnP protocol use this to register a new PnP protocol
pnp_unregister_protocol pnp_unregister_protocol
- use this function to remove a PnP protocol from the Plug and Play Layer use this function to remove a PnP protocol from the Plug and Play Layer
pnp_register_driver pnp_register_driver
- adds a PnP driver to the Plug and Play Layer adds a PnP driver to the Plug and Play Layer
- this includes driver model integration
- returns zero for success or a negative error number for failure; count this includes driver model integration
returns zero for success or a negative error number for failure; count
calls to the .add() method if you need to know how many devices bind to calls to the .add() method if you need to know how many devices bind to
the driver the driver
pnp_unregister_driver pnp_unregister_driver
- removes a PnP driver from the Plug and Play Layer removes a PnP driver from the Plug and Play Layer
Plug and Play Protocols Plug and Play Protocols
----------------------- -----------------------
This section contains information for PnP protocol developers.
This section contains information for PnP protocol developers.
The following Protocols are currently available in the computing world: The following Protocols are currently available in the computing world:
- PNPBIOS: used for system devices such as serial and parallel ports.
- ISAPNP: provides PnP support for the ISA bus - PNPBIOS:
- ACPI: among its many uses, ACPI provides information about system level used for system devices such as serial and parallel ports.
devices. - ISAPNP:
provides PnP support for the ISA bus
- ACPI:
among its many uses, ACPI provides information about system level
devices.
It is meant to replace the PNPBIOS. It is not currently supported by Linux It is meant to replace the PNPBIOS. It is not currently supported by Linux
Plug and Play but it is planned to be in the near future. Plug and Play but it is planned to be in the near future.
Requirements for a Linux PnP protocol: Requirements for a Linux PnP protocol:
1.) the protocol must use EISA IDs 1. the protocol must use EISA IDs
2.) the protocol must inform the PnP Layer of a device's current configuration 2. the protocol must inform the PnP Layer of a device's current configuration
- the ability to set resources is optional but preferred. - the ability to set resources is optional but preferred.
The following are PnP protocol related functions: The following are PnP protocol related functions:
pnp_add_device pnp_add_device
- use this function to add a PnP device to the PnP layer use this function to add a PnP device to the PnP layer
- only call this function when all wanted values are set in the pnp_dev
structure only call this function when all wanted values are set in the pnp_dev
structure
pnp_init_device pnp_init_device
- call this to initialize the PnP structure call this to initialize the PnP structure
pnp_remove_device pnp_remove_device
- call this to remove a device from the Plug and Play Layer. call this to remove a device from the Plug and Play Layer.
- it will fail if the device is still in use. it will fail if the device is still in use.
- automatically will free mem used by the device and related structures automatically will free mem used by the device and related structures
pnp_add_id pnp_add_id
- adds an EISA ID to the list of supported IDs for the specified device adds an EISA ID to the list of supported IDs for the specified device
For more information consult the source of a protocol such as For more information consult the source of a protocol such as
/drivers/pnp/pnpbios/core.c. /drivers/pnp/pnpbios/core.c.
@ -167,85 +196,97 @@ For more information consult the source of a protocol such as
Linux Plug and Play Drivers Linux Plug and Play Drivers
--------------------------- ---------------------------
This section contains information for Linux PnP driver developers.
This section contains information for Linux PnP driver developers.
The New Way The New Way
........... ^^^^^^^^^^^
1.) first make a list of supported EISA IDS
ex: 1. first make a list of supported EISA IDS
static const struct pnp_id pnp_dev_table[] = {
/* Standard LPT Printer Port */ ex::
{.id = "PNP0400", .driver_data = 0},
/* ECP Printer Port */ static const struct pnp_id pnp_dev_table[] = {
{.id = "PNP0401", .driver_data = 0}, /* Standard LPT Printer Port */
{.id = ""} {.id = "PNP0400", .driver_data = 0},
}; /* ECP Printer Port */
{.id = "PNP0401", .driver_data = 0},
{.id = ""}
};
Please note that the character 'X' can be used as a wild card in the function
portion (last four characters).
ex::
Please note that the character 'X' can be used as a wild card in the function
portion (last four characters).
ex:
/* Unknown PnP modems */ /* Unknown PnP modems */
{ "PNPCXXX", UNKNOWN_DEV }, { "PNPCXXX", UNKNOWN_DEV },
Supported PnP card IDs can optionally be defined. Supported PnP card IDs can optionally be defined.
ex: ex::
static const struct pnp_id pnp_card_table[] = {
{ "ANYDEVS", 0 },
{ "", 0 }
};
2.) Optionally define probe and remove functions. It may make sense not to static const struct pnp_id pnp_card_table[] = {
define these functions if the driver already has a reliable method of detecting { "ANYDEVS", 0 },
the resources, such as the parport_pc driver. { "", 0 }
ex: };
static int
serial_pnp_probe(struct pnp_dev * dev, const struct pnp_id *card_id, const
struct pnp_id *dev_id)
{
. . .
ex: 2. Optionally define probe and remove functions. It may make sense not to
static void serial_pnp_remove(struct pnp_dev * dev) define these functions if the driver already has a reliable method of detecting
{ the resources, such as the parport_pc driver.
. . .
consult /drivers/serial/8250_pnp.c for more information. ex::
3.) create a driver structure static int
ex: serial_pnp_probe(struct pnp_dev * dev, const struct pnp_id *card_id, const
struct pnp_id *dev_id)
{
. . .
static struct pnp_driver serial_pnp_driver = { ex::
.name = "serial",
.card_id_table = pnp_card_table,
.id_table = pnp_dev_table,
.probe = serial_pnp_probe,
.remove = serial_pnp_remove,
};
* name and id_table cannot be NULL. static void serial_pnp_remove(struct pnp_dev * dev)
{
. . .
4.) register the driver consult /drivers/serial/8250_pnp.c for more information.
ex:
static int __init serial8250_pnp_init(void) 3. create a driver structure
{
return pnp_register_driver(&serial_pnp_driver); ex::
}
static struct pnp_driver serial_pnp_driver = {
.name = "serial",
.card_id_table = pnp_card_table,
.id_table = pnp_dev_table,
.probe = serial_pnp_probe,
.remove = serial_pnp_remove,
};
* name and id_table cannot be NULL.
4. register the driver
ex::
static int __init serial8250_pnp_init(void)
{
return pnp_register_driver(&serial_pnp_driver);
}
The Old Way The Old Way
........... ^^^^^^^^^^^
A series of compatibility functions have been created to make it easy to convert A series of compatibility functions have been created to make it easy to convert
ISAPNP drivers. They should serve as a temporary solution only. ISAPNP drivers. They should serve as a temporary solution only.
They are as follows: They are as follows::
struct pnp_card *pnp_find_card(unsigned short vendor, struct pnp_card *pnp_find_card(unsigned short vendor,
unsigned short device, unsigned short device,
struct pnp_card *from) struct pnp_card *from)
struct pnp_dev *pnp_find_dev(struct pnp_card *card, struct pnp_dev *pnp_find_dev(struct pnp_card *card,
unsigned short vendor, unsigned short vendor,
unsigned short function, unsigned short function,
struct pnp_dev *from) struct pnp_dev *from)