$NetBSD: acpismbus.4,v 1.2 2010/02/06 21:57:08 wiz Exp $
Copyright (c) 2009 The NetBSD Foundation, Inc.
All rights reserved.
This code is derived from software contributed to The NetBSD Foundation
by Paul Goyette
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
.Dd February 6, 2010 .Dt ACPISMBUS 4 .Os .Sh NAME .Nm acpismbus .Nd ACPI SMBus Control Method Interface .Sh SYNOPSIS .Cd "acpismbus* at acpi?" .Cd "iic* at acpismbus?" .Sh DESCRIPTION The .Nm driver supports instances of the ACPI SMBus Control Method Interface. This enables i2c access to bus segments which might not otherwise be accessible due to missing "native" driver support. The SMBus Process Call protocol is not supported. All other SMBus protocols are supported to the extent that the underlying controller supports them. .Sh SEE ALSO .Xr acpi 4 , .Xr iic 4 .Sh HISTORY The .Nm driver appeared in .Nx 6.0 . .Sh BUGS Although .Nm SMBus Alerts can be associated with individual devices, this capability is ignored. When an .Nm SMBus Alert is generated, all devices on the i2c bus segment which have registered an interrupt routine are notified.
Copyright (c) 2009 The NetBSD Foundation, Inc.
All rights reserved.
This code is derived from software contributed to The NetBSD Foundation
by Paul Goyette
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
.Dd February 6, 2010 .Dt ACPISMBUS 4 .Os .Sh NAME .Nm acpismbus .Nd ACPI SMBus Control Method Interface .Sh SYNOPSIS .Cd "acpismbus* at acpi?" .Cd "iic* at acpismbus?" .Sh DESCRIPTION The .Nm driver supports instances of the ACPI SMBus Control Method Interface. This enables i2c access to bus segments which might not otherwise be accessible due to missing "native" driver support. The SMBus Process Call protocol is not supported. All other SMBus protocols are supported to the extent that the underlying controller supports them. .Sh SEE ALSO .Xr acpi 4 , .Xr iic 4 .Sh HISTORY The .Nm driver appeared in .Nx 6.0 . .Sh BUGS Although .Nm SMBus Alerts can be associated with individual devices, this capability is ignored. When an .Nm SMBus Alert is generated, all devices on the i2c bus segment which have registered an interrupt routine are notified.
p The SMBus CMI protocol defines a method to provide a list of devices on an i2c bus segment and their addresses. The .Nm driver makes no attempt to retrieve or process this device list.
p There is currently no way to determine if the i2c controller managed by an instance of the ACPI SMBus CMI can also be accessed using a native device driver. Therefore, the .Nm driver should not be enabled by default. If both a native driver and the .Nm driver attempt to access the same i2c bus segment, the results are undefined.