powerpc/sysdev: implement FSL GTM support

GTM stands for General-purpose Timers Module and able to generate
timer{1,2,3,4} interrupts. These timers are used by the drivers that
need time precise interrupts (like for USB transactions scheduling for
the Freescale USB Host controller as found in some QE and CPM chips),
or these timers could be used as wakeup events from the CPU deep-sleep
mode.

Things unimplemented:
1. Cascaded (32 bit) timers (1-2, 3-4).
   This is straightforward to implement when needed, two timers should
   be marked as "requested" and configured as appropriate.
2. Super-cascaded (64 bit) timers (1-2-3-4).
   This is also straightforward to implement when needed, all timers
   should be marked as "requested" and configured as appropriate.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

Documentation/powerpc/booting-without-of.txt

@@ -61,6 +61,7 @@ Table of Contents
       r) Freescale Display Interface Unit
       s) Freescale on board FPGA
       t) Freescael MSI interrupt controller
+      u) Freescale General-purpose Timers Module
 
   VII - Marvell Discovery mv64[345]6x System Controller chips
     1) The /system-controller node
@@ -2907,6 +2908,37 @@ platforms are moved over to use the flattened-device-tree model.
 		interrupt-parent = <&mpic>;
 	};
 
+    u) Freescale General-purpose Timers Module
+
+    Required properties:
+      - compatible : should be
+        "fsl,<chip>-gtm", "fsl,gtm" for SOC GTMs
+        "fsl,<chip>-qe-gtm", "fsl,qe-gtm", "fsl,gtm" for QE GTMs
+        "fsl,<chip>-cpm2-gtm", "fsl,cpm2-gtm", "fsl,gtm" for CPM2 GTMs
+      - reg : should contain gtm registers location and length (0x40).
+      - interrupts : should contain four interrupts.
+      - interrupt-parent : interrupt source phandle.
+      - clock-frequency : specifies the frequency driving the timer.
+
+    Example:
+
+    timer@500 {
+	compatible = "fsl,mpc8360-gtm", "fsl,gtm";
+	reg = <0x500 0x40>;
+	interrupts = <90 8 78 8 84 8 72 8>;
+	interrupt-parent = <&ipic>;
+	/* filled by u-boot */
+	clock-frequency = <0>;
+    };
+
+    timer@440 {
+	compatible = "fsl,mpc8360-qe-gtm", "fsl,qe-gtm", "fsl,gtm";
+	reg = <0x440 0x40>;
+	interrupts = <12 13 14 15>;
+	interrupt-parent = <&qeic>;
+	/* filled by u-boot */
+	clock-frequency = <0>;
+    };
 
 VII - Marvell Discovery mv64[345]6x System Controller chips
 ===========================================================

arch/powerpc/Kconfig

@@ -538,6 +538,12 @@ config FSL_LBC
 	help
 	  Freescale Localbus support
 
+config FSL_GTM
+	bool
+	depends on PPC_83xx || QUICC_ENGINE || CPM2
+	help
+	  Freescale General-purpose Timers support
+
 # Yes MCA RS/6000s exist but Linux-PPC does not currently support any
 config MCA
 	bool

arch/powerpc/sysdev/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_MMIO_NVRAM)	+= mmio_nvram.o
 obj-$(CONFIG_FSL_SOC)		+= fsl_soc.o
 obj-$(CONFIG_FSL_PCI)		+= fsl_pci.o $(fsl-msi-obj-y)
 obj-$(CONFIG_FSL_LBC)		+= fsl_lbc.o
+obj-$(CONFIG_FSL_GTM)		+= fsl_gtm.o
 obj-$(CONFIG_RAPIDIO)		+= fsl_rio.o
 obj-$(CONFIG_TSI108_BRIDGE)	+= tsi108_pci.o tsi108_dev.o
 obj-$(CONFIG_QUICC_ENGINE)	+= qe_lib/