@@ -10,6 +10,41 @@
compatible = "arm,integrator-ap";
dma-ranges = <0x80000000 0x0 0x80000000>;
+ cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ cpu@0 {
+ device_type = "cpu";
+ /*
+ * Since the board has pluggable CPU modules, we
+ * cannot define a proper compatible here. Let the
+ * boot loader fill in the apropriate compatible
+ * string if necessary.
+ */
+ /* compatible = "arm,arm926ej-s"; */
+ reg = <0>;
+ /*
+ * The documentation in ARM DUI 0138E page 3-12 states
+ * that the maximum frequency for this clock is 200 MHz
+ * but painful trial-and-error has proved to me that it
+ * is actually just hanging the system above 71 MHz.
+ * Sad but true.
+ */
+ /* kHz uV */
+ operating-points = <71000 0
+ 66000 0
+ 60000 0
+ 48000 0
+ 36000 0
+ 24000 0
+ 12000 0>;
+ clocks = <&cmosc>;
+ clock-names = "cpu";
+ clock-latency = <1000000>; /* 1 ms */
+ };
+ };
+
aliases {
arm,timer-primary = &timer2;
arm,timer-secondary = &timer1;
This adds the cpus node to the Integrator/AP device tree so that we have a proper placeholder to put in the DT-defined operating points for the generic DT/OPP cpufreq driver, along with the proper operating points. The old Integrator cpufreq driver would resolve the max frequency to 71MHz, and the min frequency to 12 MHz, but the clock driver can actually handle any frequency inbetween so I picked a few select frequencies as OPPs. The cpufreq framework doesn't seem to deal with sliding frequency scales, only fixed points so 7 OPPs is better than 2 atleast. We define a CPU node since this is required for cpufreq-dt, however we do not define any compatible string for the CPU since this architecture has pluggable CPU modules and we do not know which one will be used. If necessary, the CPU compatible can be filled in by the boot loader, but for just cpufreq-dt it is not required. Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- arch/arm/boot/dts/integratorap.dts | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel