1 ================================= 1 =================================
2 Linux Plug and Play Documentation 2 Linux Plug and Play Documentation
3 ================================= 3 =================================
4 4
5 :Author: Adam Belay <ambx1@neo.rr.com> 5 :Author: Adam Belay <ambx1@neo.rr.com>
6 :Last updated: Oct. 16, 2002 6 :Last updated: Oct. 16, 2002
7 7
8 8
9 Overview 9 Overview
10 -------- 10 --------
11 11
12 Plug and Play provides a means of detecting an 12 Plug and Play provides a means of detecting and setting resources for legacy or
13 otherwise unconfigurable devices. The Linux P 13 otherwise unconfigurable devices. The Linux Plug and Play Layer provides these
14 services to compatible drivers. 14 services to compatible drivers.
15 15
16 16
17 The User Interface 17 The User Interface
18 ------------------ 18 ------------------
19 19
20 The Linux Plug and Play user interface provide 20 The Linux Plug and Play user interface provides a means to activate PnP devices
21 for legacy and user level drivers that do not 21 for legacy and user level drivers that do not support Linux Plug and Play. The
22 user interface is integrated into sysfs. 22 user interface is integrated into sysfs.
23 23
24 In addition to the standard sysfs file the fol 24 In addition to the standard sysfs file the following are created in each
25 device's directory: 25 device's directory:
26 - id - displays a list of support EISA IDs 26 - id - displays a list of support EISA IDs
27 - options - displays possible resource configu 27 - options - displays possible resource configurations
28 - resources - displays currently allocated res 28 - resources - displays currently allocated resources and allows resource changes
29 29
30 activating a device 30 activating a device
31 ^^^^^^^^^^^^^^^^^^^ 31 ^^^^^^^^^^^^^^^^^^^
32 32
33 :: 33 ::
34 34
35 # echo "auto" > resources 35 # echo "auto" > resources
36 36
37 this will invoke the automatic resource config 37 this will invoke the automatic resource config system to activate the device
38 38
39 manually activating a device 39 manually activating a device
40 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 40 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
41 41
42 :: 42 ::
43 43
44 # echo "manual <depnum> <mode>" > reso 44 # echo "manual <depnum> <mode>" > resources
45 45
46 <depnum> - the configuration number 46 <depnum> - the configuration number
47 <mode> - static or dynamic 47 <mode> - static or dynamic
48 static = for next boot 48 static = for next boot
49 dynamic = now 49 dynamic = now
50 50
51 disabling a device 51 disabling a device
52 ^^^^^^^^^^^^^^^^^^ 52 ^^^^^^^^^^^^^^^^^^
53 53
54 :: 54 ::
55 55
56 # echo "disable" > resources 56 # echo "disable" > resources
57 57
58 58
59 EXAMPLE: 59 EXAMPLE:
60 60
61 Suppose you need to activate the floppy disk c 61 Suppose you need to activate the floppy disk controller.
62 62
63 1. change to the proper directory, in my case 63 1. change to the proper directory, in my case it is
64 /driver/bus/pnp/devices/00:0f:: 64 /driver/bus/pnp/devices/00:0f::
65 65
66 # cd /driver/bus/pnp/devices/00:0f 66 # cd /driver/bus/pnp/devices/00:0f
67 # cat name 67 # cat name
68 PC standard floppy disk controller 68 PC standard floppy disk controller
69 69
70 2. check if the device is already active:: 70 2. check if the device is already active::
71 71
72 # cat resources 72 # cat resources
73 DISABLED 73 DISABLED
74 74
75 - Notice the string "DISABLED". This means 75 - Notice the string "DISABLED". This means the device is not active.
76 76
77 3. check the device's possible configurations 77 3. check the device's possible configurations (optional)::
78 78
79 # cat options 79 # cat options
80 Dependent: 01 - Priority acceptable 80 Dependent: 01 - Priority acceptable
81 port 0x3f0-0x3f0, align 0x7, size 81 port 0x3f0-0x3f0, align 0x7, size 0x6, 16-bit address decoding
82 port 0x3f7-0x3f7, align 0x0, size 82 port 0x3f7-0x3f7, align 0x0, size 0x1, 16-bit address decoding
83 irq 6 83 irq 6
84 dma 2 8-bit compatible 84 dma 2 8-bit compatible
85 Dependent: 02 - Priority acceptable 85 Dependent: 02 - Priority acceptable
86 port 0x370-0x370, align 0x7, size 86 port 0x370-0x370, align 0x7, size 0x6, 16-bit address decoding
87 port 0x377-0x377, align 0x0, size 87 port 0x377-0x377, align 0x0, size 0x1, 16-bit address decoding
88 irq 6 88 irq 6
89 dma 2 8-bit compatible 89 dma 2 8-bit compatible
90 90
91 4. now activate the device:: 91 4. now activate the device::
92 92
93 # echo "auto" > resources 93 # echo "auto" > resources
94 94
95 5. finally check if the device is active:: 95 5. finally check if the device is active::
96 96
97 # cat resources 97 # cat resources
98 io 0x3f0-0x3f5 98 io 0x3f0-0x3f5
99 io 0x3f7-0x3f7 99 io 0x3f7-0x3f7
100 irq 6 100 irq 6
101 dma 2 101 dma 2
102 102
103 also there are a series of kernel parameters:: 103 also there are a series of kernel parameters::
104 104
105 pnp_reserve_irq=irq1[,irq2] .... 105 pnp_reserve_irq=irq1[,irq2] ....
106 pnp_reserve_dma=dma1[,dma2] .... 106 pnp_reserve_dma=dma1[,dma2] ....
107 pnp_reserve_io=io1,size1[,io2,size2] . 107 pnp_reserve_io=io1,size1[,io2,size2] ....
108 pnp_reserve_mem=mem1,size1[,mem2,size2 108 pnp_reserve_mem=mem1,size1[,mem2,size2] ....
109 109
110 110
111 111
112 The Unified Plug and Play Layer 112 The Unified Plug and Play Layer
113 ------------------------------- 113 -------------------------------
114 114
115 All Plug and Play drivers, protocols, and serv 115 All Plug and Play drivers, protocols, and services meet at a central location
116 called the Plug and Play Layer. This layer is 116 called the Plug and Play Layer. This layer is responsible for the exchange of
117 information between PnP drivers and PnP protoc 117 information between PnP drivers and PnP protocols. Thus it automatically
118 forwards commands to the proper protocol. Thi 118 forwards commands to the proper protocol. This makes writing PnP drivers
119 significantly easier. 119 significantly easier.
120 120
121 The following functions are available from the 121 The following functions are available from the Plug and Play Layer:
122 122
123 pnp_get_protocol 123 pnp_get_protocol
124 increments the number of uses by one 124 increments the number of uses by one
125 125
126 pnp_put_protocol 126 pnp_put_protocol
127 deincrements the number of uses by one 127 deincrements the number of uses by one
128 128
129 pnp_register_protocol 129 pnp_register_protocol
130 use this to register a new PnP protocol 130 use this to register a new PnP protocol
131 131
132 pnp_unregister_protocol 132 pnp_unregister_protocol
133 use this function to remove a PnP protocol f 133 use this function to remove a PnP protocol from the Plug and Play Layer
134 134
135 pnp_register_driver 135 pnp_register_driver
136 adds a PnP driver to the Plug and Play Layer 136 adds a PnP driver to the Plug and Play Layer
137 137
138 this includes driver model integration 138 this includes driver model integration
139 returns zero for success or a negative error 139 returns zero for success or a negative error number for failure; count
140 calls to the .add() method if you need to kn 140 calls to the .add() method if you need to know how many devices bind to
141 the driver 141 the driver
142 142
143 pnp_unregister_driver 143 pnp_unregister_driver
144 removes a PnP driver from the Plug and Play 144 removes a PnP driver from the Plug and Play Layer
145 145
146 146
147 147
148 Plug and Play Protocols 148 Plug and Play Protocols
149 ----------------------- 149 -----------------------
150 150
151 This section contains information for PnP prot 151 This section contains information for PnP protocol developers.
152 152
153 The following Protocols are currently availabl 153 The following Protocols are currently available in the computing world:
154 154
155 - PNPBIOS: 155 - PNPBIOS:
156 used for system devices such as serial and 156 used for system devices such as serial and parallel ports.
157 - ISAPNP: 157 - ISAPNP:
158 provides PnP support for the ISA bus 158 provides PnP support for the ISA bus
159 - ACPI: 159 - ACPI:
160 among its many uses, ACPI provides informa 160 among its many uses, ACPI provides information about system level
161 devices. 161 devices.
162 162
163 It is meant to replace the PNPBIOS. It is not 163 It is meant to replace the PNPBIOS. It is not currently supported by Linux
164 Plug and Play but it is planned to be in the n 164 Plug and Play but it is planned to be in the near future.
165 165
166 166
167 Requirements for a Linux PnP protocol: 167 Requirements for a Linux PnP protocol:
168 1. the protocol must use EISA IDs 168 1. the protocol must use EISA IDs
169 2. the protocol must inform the PnP Layer of a 169 2. the protocol must inform the PnP Layer of a device's current configuration
170 170
171 - the ability to set resources is optional but 171 - the ability to set resources is optional but preferred.
172 172
173 The following are PnP protocol related functio 173 The following are PnP protocol related functions:
174 174
175 pnp_add_device 175 pnp_add_device
176 use this function to add a PnP device to the 176 use this function to add a PnP device to the PnP layer
177 177
178 only call this function when all wanted valu 178 only call this function when all wanted values are set in the pnp_dev
179 structure 179 structure
180 180
181 pnp_init_device 181 pnp_init_device
182 call this to initialize the PnP structure 182 call this to initialize the PnP structure
183 183
184 pnp_remove_device 184 pnp_remove_device
185 call this to remove a device from the Plug a 185 call this to remove a device from the Plug and Play Layer.
186 it will fail if the device is still in use. 186 it will fail if the device is still in use.
187 automatically will free mem used by the devi 187 automatically will free mem used by the device and related structures
188 188
189 pnp_add_id 189 pnp_add_id
190 adds an EISA ID to the list of supported IDs 190 adds an EISA ID to the list of supported IDs for the specified device
191 191
192 For more information consult the source of a p 192 For more information consult the source of a protocol such as
193 /drivers/pnp/pnpbios/core.c. 193 /drivers/pnp/pnpbios/core.c.
194 194
195 195
196 196
197 Linux Plug and Play Drivers 197 Linux Plug and Play Drivers
198 --------------------------- 198 ---------------------------
199 199
200 This section contains information for Linux Pn 200 This section contains information for Linux PnP driver developers.
201 201
202 The New Way 202 The New Way
203 ^^^^^^^^^^^ 203 ^^^^^^^^^^^
204 204
205 1. first make a list of supported EISA IDS 205 1. first make a list of supported EISA IDS
206 206
207 ex:: 207 ex::
208 208
209 static const struct pnp_id pnp_dev_tab 209 static const struct pnp_id pnp_dev_table[] = {
210 /* Standard LPT Printer Port * 210 /* Standard LPT Printer Port */
211 {.id = "PNP0400", .driver_data 211 {.id = "PNP0400", .driver_data = 0},
212 /* ECP Printer Port */ 212 /* ECP Printer Port */
213 {.id = "PNP0401", .driver_data 213 {.id = "PNP0401", .driver_data = 0},
214 {.id = ""} 214 {.id = ""}
215 }; 215 };
216 216
217 Please note that the character 'X' can be u 217 Please note that the character 'X' can be used as a wild card in the function
218 portion (last four characters). 218 portion (last four characters).
219 219
220 ex:: 220 ex::
221 221
222 /* Unknown PnP modems */ 222 /* Unknown PnP modems */
223 { "PNPCXXX", UNKNOW 223 { "PNPCXXX", UNKNOWN_DEV },
224 224
225 Supported PnP card IDs can optionally be de 225 Supported PnP card IDs can optionally be defined.
226 ex:: 226 ex::
227 227
228 static const struct pnp_id pnp_card_ta 228 static const struct pnp_id pnp_card_table[] = {
229 { "ANYDEVS", 229 { "ANYDEVS", 0 },
230 { "", 230 { "", 0 }
231 }; 231 };
232 232
233 2. Optionally define probe and remove function 233 2. Optionally define probe and remove functions. It may make sense not to
234 define these functions if the driver alread 234 define these functions if the driver already has a reliable method of detecting
235 the resources, such as the parport_pc drive 235 the resources, such as the parport_pc driver.
236 236
237 ex:: 237 ex::
238 238
239 static int 239 static int
240 serial_pnp_probe(struct pnp_dev * dev, 240 serial_pnp_probe(struct pnp_dev * dev, const struct pnp_id *card_id, const
241 struct pnp_id *dev_id) 241 struct pnp_id *dev_id)
242 { 242 {
243 . . . 243 . . .
244 244
245 ex:: 245 ex::
246 246
247 static void serial_pnp_remove(struct p 247 static void serial_pnp_remove(struct pnp_dev * dev)
248 { 248 {
249 . . . 249 . . .
250 250
251 consult /drivers/serial/8250_pnp.c for more 251 consult /drivers/serial/8250_pnp.c for more information.
252 252
253 3. create a driver structure 253 3. create a driver structure
254 254
255 ex:: 255 ex::
256 256
257 static struct pnp_driver serial_pnp_dr 257 static struct pnp_driver serial_pnp_driver = {
258 .name = "serial", 258 .name = "serial",
259 .card_id_table = pnp_card_tab 259 .card_id_table = pnp_card_table,
260 .id_table = pnp_dev_tabl 260 .id_table = pnp_dev_table,
261 .probe = serial_pnp_p 261 .probe = serial_pnp_probe,
262 .remove = serial_pnp_r 262 .remove = serial_pnp_remove,
263 }; 263 };
264 264
265 * name and id_table cannot be NULL. 265 * name and id_table cannot be NULL.
266 266
267 4. register the driver 267 4. register the driver
268 268
269 ex:: 269 ex::
270 270
271 static int __init serial8250_pnp_init( 271 static int __init serial8250_pnp_init(void)
272 { 272 {
273 return pnp_register_driver(&se 273 return pnp_register_driver(&serial_pnp_driver);
274 } 274 }
275 275
276 The Old Way 276 The Old Way
277 ^^^^^^^^^^^ 277 ^^^^^^^^^^^
278 278
279 A series of compatibility functions have been 279 A series of compatibility functions have been created to make it easy to convert
280 ISAPNP drivers. They should serve as a tempor 280 ISAPNP drivers. They should serve as a temporary solution only.
281 281
282 They are as follows:: 282 They are as follows::
283 283
284 struct pnp_dev *pnp_find_dev(struct pn 284 struct pnp_dev *pnp_find_dev(struct pnp_card *card,
285 unsigned 285 unsigned short vendor,
286 unsigned 286 unsigned short function,
287 struct pn 287 struct pnp_dev *from)
288 288
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