diff options
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man4/man4.i386/CPU_ELAN.4 | 127 |
1 files changed, 87 insertions, 40 deletions
diff --git a/share/man/man4/man4.i386/CPU_ELAN.4 b/share/man/man4/man4.i386/CPU_ELAN.4 index f3148b5..7fe7741 100644 --- a/share/man/man4/man4.i386/CPU_ELAN.4 +++ b/share/man/man4/man4.i386/CPU_ELAN.4 @@ -1,4 +1,4 @@ -.\" Copyright (c) 2003 Poul-Henning Kamp <phk@FreeBSD.org> +.\" Copyright (c) 2003 Poul-Henning Kamp <phk@FreeBSD.org> .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without @@ -25,87 +25,134 @@ .\" $FreeBSD$ .\" .Dd November 23, 2003 -.Dt CPU_ELAN 4 +.Dt CPU_ELAN 4 i386 .Os .Sh NAME .Nm CPU_ELAN .Nd AMD Elan 520 CPU support .Sh SYNOPSIS -.Cd options CPU_ELAN -.Cd options CPU_ELAN_PPS -.Cd options CPU_ELAN_XTAL -.Cd sysctl machdep.elan_gpio_config -.Cd sysctl machdep.elan_freq -.Cd options CPU_SOEKRIS +.Cd "options CPU_ELAN" +.Cd "options CPU_ELAN_PPS" +.Cd "options CPU_ELAN_XTAL" +.Bl -item -compact +.It +.Va machdep.elan_gpio_config +.It +.Va machdep.elan_freq +.El +.Cd "options CPU_SOEKRIS" .Sh DESCRIPTION -.Cd options CPU_ELAN -Enables support for the AMD Elan 520 CPU. +The +.Cd "options CPU_ELAN" +enables support for the AMD Elan 520 CPU. .Pp -A device "/dev/elan-mmcr" exports the MMCR register bank to userland +A device +.Pa /dev/elan-mmcr +exports the MMCR register bank to userland using .Xr mmap 2 . .Pp -The "i8254" timer will be adjusted to the slightly unorthodox -frequency 1189161Hz (32768 * 45 * 25 / 31) employed by the Elan. +The +.Tn i8254 +timer will be adjusted to the slightly unorthodox +frequency 1189161 Hz (32768 * 45 * 25 / 31) employed by the Elan. .Pp -A timecounter named "ELAN" is implemented using the general purpose timer 2, +A timecounter named +.Dq Li ELAN +is implemented using the general purpose timer 2, but it will not be usable unless HZ is configured at 150 or higher. -This timecounter is much better than the "i8254" timecounter and should be +This timecounter is much better than the +.Dq Li i8254 +timecounter and should be used at all times. .Pp The -.Cd sysctl machdep.elan_gpio_config +.Va machdep.elan_gpio_config +.Xr sysctl 8 +variable enables configuration of the GPIO pins of the CPU. The string must be exactly 32 characters long. -A '-' means the GPIO is unavailable. -A 'l' (lower-case L) configures a +A +.Ql - +means the GPIO is unavailable. +A +.Ql l +(lower-case ell) configures a .Xr led 4 device (active low). -A 'L' configures a +A +.Ql L +configures a .Xr led 4 -device (active higH). -A '.' means no configuration for this GPIO. +device (active high). +A +.Ql \&. +means no configuration for this GPIO. These .Xr led 4 -devices will be named "/dev/led/gpio%d". -For meaning of 'P', 'e' and 'E', see under -.Cd options CPU_ELAN_PPS . +devices will be named +.Pa /dev/led/gpio%d . +For meaning of +.Ql P , +.Ql e +and +.Ql E , +see under +.Cd "options CPU_ELAN_PPS" . .Pp The -.Cd options CPU_ELAN_XTAL -and -.Cd sysctl machdep.elan_freq +.Cd "options CPU_ELAN_XTAL" +and the +.Va machdep.elan_freq +.Xr sysctl 8 +variable can be used to set the CPU clock crystal frequency in Hz. The default is 33333333 Hz. .Pp The -.Cd options CPU_ELAN_PPS +.Cd "options CPU_ELAN_PPS" enables precision timestamping using the RFC2783 PPS-API via the -"/dev/elan-mmcr" device. -The resolution will be approx 125nsec and the precision \(+- 125nsec. -(for 125 nsec read "4 / CPU clock crystal frequency") +.Pa /dev/elan-mmcr +device. +The resolution will be approximately 125 nsec +and the precision \(+- 125 nsec. +(For 125 nsec read +.Dq "4 / CPU clock crystal frequency" . ) .Pp The input signal must be connected to the TMR1IN pin and a GPIO pin. -The GPIO pin must be configured with a 'P' in -.Cd sysctl machdep.elan_gpio_config . +The GPIO pin must be configured with a +.Ql P +in +.Va machdep.elan_gpio_config . .Pp -In addition one GPIO pin can be configured with either 'e' (active low) -or 'E' (active high) to become a "echo" output of the input signal. +In addition, one GPIO pin can be configured with either +.Ql e +(active low) +or +.Ql E +(active high) to become a +.Dq echo +output of the input signal. Please notice that this signal is not suitable for calibration. .Pp If the -.Cd options CPU_SOEKRIS -option is given, the support will additionally be tailored to the +.Cd "options CPU_SOEKRIS" +is given, the support will additionally be tailored to the Soekris Engineering 45xx series of embedded computers. -The "error" led will be configured (as "/dev/led/error") and the GPIO pins which are not +The +.Dq error +led will be configured (as +.Pa /dev/led/error ) +and the GPIO pins which are not available will be disabled. .Sh SEE ALSO -.Xr sysctl 8 , +.Xr led 4 , +.Xr sysctl 8 .Sh HISTORY The .Nm code first appeared in -.Fx 5.x . +.Fx 4.7 . .Sh AUTHORS .An "Poul-Henning Kamp" Aq phk@FreeBSD.org |