xref: /freebsd/share/man/man4/man4.i386/pnp.4 (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
1.\" pnp(4) - manual page for the scanner device driver `asc'
2.\"
3.\"
4.\" Copyright (c) 1997 Luigi Rizzo
5.\"
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13.\"    documentation and/or other materials provided with the distribution.
14.\" 3. All advertising materials mentioning features or use of this software
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16.\"	This product includes software developed by Luigi Rizzo.
17.\" 4. The name of the author may not be used to endorse or promote products
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31.\" $FreeBSD$
32.\"
33.Dd September 7, 1997
34.Dt PNP 4 i386
35.Os FreeBSD
36.Sh NAME
37.Nm pnp
38.Nd support for PnP devices
39.Sh SYNOPSIS
40.Cd controller pnp0
41.Sh DESCRIPTION
42Support for PnP devices in
43.Fx
44allows the user to override the
45configuration of PnP cards, and device drivers to fetch/modify
46parameters in the card's configuration space.
47.Pp
48The manual override mechanism requires the kernel to be compiled with
49.Cd options USERCONFIG .
50In this case, the kernel keeps a table of fixed size (20 entries as a
51default) where configuration data are held for PnP devices.
52Each
53PnP card can contain several independent devices (5 or 6 is not
54unusual).
55.Pp
56By booting the kernel with the
57.Dq Fl c
58flag, commands are available to
59modify the configuration of PnP cards.
60Commands start with the
61sequence:
62.Dl pnp CSN LDN
63where CSN and LDN are the Card Select Number and Logical Device Number
64associated to the device.
65Following this sequence any combination of
66the following commands can be used:
67.Bl -tag -width "mmmmmmmmmm""
68.It Dv irqN line
69Sets the irq line for interrupt 0 or 1 on the card.
70Line=0 means the line
71is unused.
72.It Dv drqN n
73Sets the drq channel used for DMA 0 or 1 on the card.
74Channel=4 means
75the channel is unused.
76.It Dv portN address
77Sets the base address for the N-th port's range (N=0..7). address=0
78means that the port is not used.
79.It Dv memN address
80Sets the base address for the N-th memory's range (N=0..3). address=0
81means that the memory range is not used.
82.It Dv bios
83Makes the PnP device use the configuration set by the BIOS.
84This
85is the default, and is generally ok if your BIOS has PnP support.
86If BIOS is used, then other parameters are ignored except "flags".
87.It Dv os
88Makes the PnP device to use the configuration specified in this entry.
89.It Dv enable
90Enables the PnP device.
91.It Dv disable
92Disables the PnP device.
93.It Dv delete
94Frees the entry used for the device, so that it can be used for
95another device with a different CSN/LDN pair.
96.It Dv flags
97Sets the value of a 32-bit flags entry which is passed to the device
98driver.
99This can be used to set special operation modes (e.g. SB vs. WSS
100emulation on some sound cards, etc.).
101.El
102.Pp
103The current content of the table can be printed using the
104.Ic ls
105command in userconfig.
106In addition to modifications done by the user,
107the table contains an entry for
108all logical devices accessed by a PnP device driver.
109.Pp
110Modifications to
111the table will be saved to the boot image on the filesystem by the
112.Xr kget 8
113command.
114.Pp
115.Sh DEVICE DRIVER SUPPORT FOR PnP
116PnP devices are automatically recognized and configured by the kernel.
117A PnP device is identified by the following data structure:
118.Bd -literal
119struct pnp_device {
120	char	*pd_name;
121	char	*(*pd_probe ) (u_long csn, u_long vendor_id);
122	void	(*pd_attach ) (u_long csn, u_long vend_id, char * name,
123		    struct isa_device *dev);
124	u_long	*pd_count;
125	u_int	*imask;
126	struct	isa_device dev;
127};
128.Ed
129.Pp
130The probe routine must check that the vendor_id passed is a
131recognized one, that any necessary devices on the card are enabled,
132and returns a NULL value in case of failure or a non-NULL value
133(generally a pointer to the device name) unpon success.  In the probe
134routine, the function
135.Fn read_pnp_parms
136can be used to check that the logical devices are enabled.
137.Pp
138The attach routine should do all the necessary initialization, enable
139the PnP card to ISA accesses, fetch the configuration, and call the ISA
140driver for the device.
141.Pp
142The following routines and data structures can be used:
143.Bl -tag -width "xxxxxxxxxx"
144.It Dv struct pnp_cinfo
145This data structure (defined in /sys/i386/isa/pnp.h) contains all
146informations related to a PnP logical device.
147.It Fn read_pnp_parms "struct pnp_cinfo *d" "int ldn"
148This function returns the configuration of the requested
149logical device.
150It is not possible to specify a CSN since this function
151is only meant to be used during probe and attach routines
152.It Fn write_pnp_parms "struct pnp_cinfo *d" "int ldn"
153This function sets the parameters of the requested logical device.
154At
155the same time, it updates the entry in the kernel override table.
156Device drivers in general should
157.Em not
158modify the configuration of a device, since either the BIOS or the user
159(through userconfig) should know better what to do.
160In particular,
161device driver
162.Em should not enable
163a logical device which has
164been found disabled,
165since this would defeat the override mechanism in userconfig.
166Device
167drivers may disable a logical device, or a port range, etc, but should
168do so only that particular device or parameter is known to cause
169troubles.
170.It Fn enable_pnp_card void
171This function
172.Em must
173be used in the attach routine
174.Em only ,
175before accessing the card's ISA ports/memory address ranges.
176.El
177.Pp
178.Sh SEE ALSO
179.Xr kget 8
180.Sh BUGS
181There is no support for visual configuration of PnP devices.
182It would be nice to have commands in userconfig to fetch the
183configuration of PnP devices.
184.Sh AUTHORS
185.An -nosplit
186PnP support was written by
187.An Luigi Rizzo ,
188based on initial work done by
189.An Sujal Patel .
190.Sh HISTORY
191The
192.Nm
193driver first appeared in
194.Fx 2.2.5 .
195