gnu: services: Add power-profiles-daemon-service-type.

* gnu/services/pm.scm
(power-profiles-configuration): New configuration.
(power-profiles-daemon-shepherd-service): New procedure.
(power-profiles-daemon-activation): New variable.
(power-profiles-daemon-service-type): New procedure.
* doc/guix.texi (Power Management Services): Document it.

Change-Id: Ib035d993ed82eec2a43f3ba2b4c92f77e08a0fd7
Signed-off-by: Christopher Baines <mail@cbaines.net>

doc/guix.texi

@@ -127,6 +127,7 @@ Copyright @copyright{} 2023 Tomas Volf@*
 Copyright @copyright{} 2024 Herman Rimm@*
 Copyright @copyright{} 2024 Matthew Trzcinski@*
 Copyright @copyright{} 2024 Richard Sent@*
+Copyright @copyright{} 2024 Dariqq@*
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -34711,6 +34712,45 @@ Base URL to use for links to laminar itself.
 @node Power Management Services
 @subsection Power Management Services
 
+@cindex power-profiles-daemon
+@subsubheading Power Profiles Daemon
+
+The @code{(gnu services pm)} module provides a Guix service definition for
+the Linux Power Profiles Daemon, which makes power profiles handling
+available over D-Bus.
+
+The available profiles consist of the default @samp{balanced} mode, a @samp{power-saver} mode
+and on supported systems a @samp{performance} mode.
+
+@quotation Important
+The @code{power-profiles-daemon} conflicts with other power management tools
+like @code{tlp}. Using both together is not recommended.
+@end quotation
+
+@defvar power-profiles-daemon-service-type
+This is the service type for the
+@uref{https://gitlab.freedesktop.org/upower/power-profiles-daemon/, Power Profiles Daemon}.
+The value for this service is a @code{power-profiles-daemon-configuration}.
+
+To enable the Power Profiles Daemon with default configuration
+add this line to your services:
+
+@lisp
+(service power-profiles-daemon-service-type)
+@end lisp
+@end defvar
+
+@deftp {Data Type} power-profiles-daemon-configuration
+Data type representing the configuration of @code{power-profiles-daemon-service-type}.
+
+@table @asis
+@item @code{power-profiles-daemon} (default: @code{power-profiles-daemon}) (type: file-like)
+Package object of power-profiles-daemon.
+
+@end table
+@end deftp
+
+
 @cindex tlp
 @cindex power management with TLP
 @subsubheading TLP daemon

gnu/services/pm.scm

@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
+;;; Copyright © 2024 Dariqq <dariqq@posteo.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -21,18 +22,75 @@
   #:use-module (guix packages)
   #:use-module (guix records)
   #:use-module (gnu packages admin)
+  #:use-module (gnu packages freedesktop)
   #:use-module (gnu packages linux)
   #:use-module (gnu services)
   #:use-module (gnu services base)
   #:use-module (gnu services configuration)
+  #:use-module (gnu services dbus)
   #:use-module (gnu services shepherd)
   #:use-module (gnu system shadow)
-  #:export (tlp-service-type
+  #:export (power-profiles-daemon-service-type
+            power-profiles-daemon-configuration
+
+            tlp-service-type
             tlp-configuration
 
             thermald-configuration
             thermald-service-type))
 
+;;;
+;;; power-profiles-daemon
+;;;
+
+(define-configuration/no-serialization power-profiles-daemon-configuration
+  (power-profiles-daemon
+   (file-like power-profiles-daemon)
+   "The power-profiles-daemon package."))
+
+(define (power-profiles-daemon-shepherd-service config)
+  (match-record
+      config <power-profiles-daemon-configuration>
+      (power-profiles-daemon)
+    (list (shepherd-service
+           (provision '(power-profiles-daemon))
+           (requirement '(dbus-system))
+           (documentation "Run the power-profiles-daemon.")
+           (start #~(make-forkexec-constructor
+                     (list #$(file-append power-profiles-daemon
+                                          "/libexec/power-profiles-daemon"))))
+           (stop #~(make-kill-destructor))))))
+
+(define %power-profiles-daemon-activation
+  #~(begin
+      (use-modules (guix build utils))
+      (mkdir-p "/var/lib/power-profiles-daemon")))
+
+(define power-profiles-daemon-service-type
+  (let ((config->package
+         (compose list power-profiles-daemon-configuration-power-profiles-daemon)))
+    (service-type
+     (name 'power-profiles-daemon)
+     (extensions (list
+                  (service-extension shepherd-root-service-type
+                                     power-profiles-daemon-shepherd-service)
+                  (service-extension dbus-root-service-type
+                                     config->package)
+                  (service-extension polkit-service-type
+                                     config->package)
+                  (service-extension profile-service-type
+                                     config->package)
+                  (service-extension activation-service-type
+                                     (const %power-profiles-daemon-activation))))
+     (default-value (power-profiles-daemon-configuration))
+     (description "Run the power-profiles-daemon"))))
+
+
+
+;;;
+;;; tlp
+;;;
+
 (define (uglify-field-name field-name)
   (let ((str (symbol->string field-name)))
     (string-join (string-split