luci-app-statistics: add support for CPU frequency scaling stats

Add support for 'cpufreq' plugin in collectd, which monitors
the CPU cores' frequencies. Some platforms enable dynamic
frequency scaling according to CPU load.

'cpufreq' plugin can currently be built for x86 and mvebu.
(and it should likely be enabled also for ipq806x)

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

applications/luci-app-statistics/luasrc/controller/luci_statistics/luci_statistics.lua

@@ -25,6 +25,7 @@ function index()
 
 		conntrack	= _("Conntrack"),
 		cpu			= _("Processor"),
+		cpufreq		= _("CPU Frequency"),
 		csv			= _("CSV Output"),
 		df			= _("Disk Space Usage"),
 		disk		= _("Disk Usage"),
@@ -56,7 +57,7 @@ function index()
 	-- our collectd menu
 	local collectd_menu = {
 		output  = { "csv", "network", "rrdtool", "unixsock" },
-		general = { "cpu", "df", "disk", "email", "entropy", "exec", "irq", "load", "memory", "nut", "processes", "sensors", "uptime" },
+		general = { "cpu", "cpufreq", "df", "disk", "email", "entropy", "exec", "irq", "load", "memory", "nut", "processes", "sensors", "uptime" },
 		network = { "conntrack", "dns", "interface", "iptables", "netlink", "olsrd", "openvpn", "ping", "splash_leases", "tcpconns", "iwinfo" }
 	}
 

applications/luci-app-statistics/luasrc/model/cbi/luci_statistics/cpufreq.lua

@@ -0,0 +1,14 @@
+-- Licensed to the public under the Apache License 2.0.
+
+m = Map("luci_statistics",
+	translate("CPU Frequency Plugin Configuration"),
+	translate("This plugin collects statistics about the processor frequency scaling."))
+
+-- collectd_cpufreq config section
+s = m:section( NamedSection, "collectd_cpufreq", "luci_statistics" )
+
+-- collectd_cpufreq.enable
+enable = s:option( Flag, "enable", translate("Enable this plugin") )
+enable.default = 0
+
+return m

applications/luci-app-statistics/luasrc/statistics/rrdtool/definitions/cpufreq.lua

@@ -0,0 +1,25 @@
+-- Licensed to the public under the Apache License 2.0.
+
+module("luci.statistics.rrdtool.definitions.cpufreq",package.seeall)
+
+function rrdargs( graph, plugin, plugin_instance, dtype )
+
+	return {
+		title = "%H: Processor frequency",
+		alt_autoscale = true,
+		vlabel = "Frequency (Hz)",
+		number_format = "%4.0lf%s",
+		data = {
+			instances = {
+				cpufreq = { "3", "2", "1", "0" }
+			},
+			options = {
+				cpufreq_0 = { color = "ff0000", title = "Core 0", noarea=true, overlay=true },
+				cpufreq_1 = { color = "0000ff", title = "Core 1", noarea=true, overlay=true },
+				cpufreq_2 = { color = "00ff00", title = "Core 2", noarea=true, overlay=true },
+				cpufreq_3 = { color = "00ffff", title = "Core 3", noarea=true, overlay=true }
+			}
+		}
+	}
+end
+

applications/luci-app-statistics/root/etc/config/luci_statistics

@@ -55,6 +55,9 @@ config statistics 'collectd_conntrack'
 config statistics 'collectd_cpu'
 	option enable '1'
 
+config statistics 'collectd_cpufreq'
+	option enable '0'
+
 config statistics 'collectd_df'
 	option enable '0'
 	option Devices '/dev/mtdblock/4'

applications/luci-app-statistics/root/usr/bin/stat-genconfig

@@ -273,6 +273,12 @@ plugins = {
 		{ }
 	},
 
+	cpufreq	= {
+		{ },
+		{ },
+		{ }
+	},
+
 	csv	= {
 		{ "DataDir" },
 		{ "StoreRates" },