sh: CMT platform driver using timer_inc

From: Magnus Damm <[email protected]>

CMT driver for the SuperH timer base code implementation V3. Both 16-bit and 32-bit CMT versions are supported, but only 32-bit is tested. This driver only contains hardware specific bits, the logic handling clock events and clock sources is performed by the timer_inc helper code.

Works fine as clock source and/or event in periodic or oneshot mode. Tested on sh7722 and sh7723, but should work with any cpu/architecture.

---

Changes since V2 include:
- Rewrote driver to platform driver and early timer
- Only control clocks and hardware registers in disable()/enable()
- Removed exported struct from sh_timer.c/sh_timer.h
- sh_timer_early_probe() is used for early timer setup

Changes since V1 include:
- Reworked private data handling - no more union in sh_timer.h
- Made spinlock static
- Use setup_irq() to request early interrupt
- Removed request_mem_region()/free_mem_region()
- Removed sysdev code

 arch/sh/Kconfig              |    7 
 drivers/clocksource/Makefile |    1 
 drivers/clocksource/sh_cmt.c |  366 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 374 insertions(+)

@@ -394,6 +394,13 @@ config SH_TIMER
 	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 
+config SH_TIMER_CMT
+	def_bool y
+	prompt "CMT timer support"
+	depends on SH_TIMER
+	help
+	  This enables build of the CMT system timer driver.
+
 config SH_TMU
 	def_bool y
 	prompt "TMU timer support"

@@ -3,3 +3,4 @@ obj-$(CONFIG_X86_CYCLONE_TIMER)	+= cyclo
 obj-$(CONFIG_X86_PM_TIMER)	+= acpi_pm.o
 obj-$(CONFIG_SCx200HR_TIMER)	+= scx200_hrt.o
 obj-$(CONFIG_SH_TIMER)		+= sh_timer.o
+obj-$(CONFIG_SH_TIMER_CMT)	+= sh_cmt.o timer_inc.o