clocksource: import ARC timer driver

This adds support for

 - CONFIG_ARC_TIMERS : legacy 32-bit TIMER0 and TIMER1 which count UP
   from @CNT to @LIMIT, before optionally triggering an interrupt.
   These are programmed using ARC auxiliary register interface.
   These are present in all ARC cores (ARC700 and ARC HS38)
   TIMER0 serves as clockevent for all ARC linux builds.
   TIMER1 is used for clocksource in arc700 builds.

 - CONFIG_ARC_TIMERS_64BIT: 64-bit counters, RTC and GFRC found in
   ARC HS38 cores. These are independnet IP blocks with different
   programming model respectively.

Link: http://lkml.kernel.org/r/20161111231132.GA4186@mai
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/MAINTAINERS b/MAINTAINERS
index 8d4148406923f6cd77a277bd95c43b7d46e2288b..34160a2dd1310eb0905bd1c80b9306c2a62254a4 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11662,6 +11662,7 @@ S:      Supported
 F:     arch/arc/
 F:     Documentation/devicetree/bindings/arc/*
 F:     Documentation/devicetree/bindings/interrupt-controller/snps,arc*
+F:     drivers/clocksource/arc_timer.c
 F:     drivers/tty/serial/arc_uart.c
 T:     git git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc.git
 

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index bde3e558d8bc8682cd5f860f18eec7acc1aefd7c..ab12723d39a01d8751807728a43c7b08cdc6a814 100644 (file)
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -8,9 +8,9 @@
 
 config ARC
        def_bool y
+       select ARC_TIMERS
        select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC
        select BUILDTIME_EXTABLE_SORT
-       select CLKSRC_OF
        select CLONE_BACKWARDS
        select COMMON_CLK
        select GENERIC_ATOMIC64 if !ISA_ARCV2 || !(ARC_HAS_LL64 && ARC_HAS_LLSC)
@@ -115,6 +115,7 @@ config ISA_ARCOMPACT
 
 config ISA_ARCV2
        bool "ARC ISA v2"
+       select ARC_TIMERS_64BIT
        help
          ISA for the Next Generation ARC-HS cores
 
@@ -410,10 +411,6 @@ config ARC_HAS_DIV_REM
        bool "Insn: div, divu, rem, remu"
        default y
 
-config ARC_TIMERS_64BIT
-       bool "64-bit r/o cycle counters RTC (up) and GFRC (smp)"
-       default y
-
 config ARC_NUMBER_OF_INTERRUPTS
        int "Number of interrupts"
        range 8 240

diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
index cfcdedf52ff8baa1ebbc58c168e386884cd2b534..8942c5c3b4c519eed7227200eaaa54cc4468698e 100644 (file)
--- a/arch/arc/kernel/Makefile
+++ b/arch/arc/kernel/Makefile
@@ -8,7 +8,7 @@
 # Pass UTS_MACHINE for user_regset definition
 CFLAGS_ptrace.o                += -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
-obj-y  := arcksyms.o setup.o irq.o time.o reset.o ptrace.o process.o devtree.o
+obj-y  := arcksyms.o setup.o irq.o reset.o ptrace.o process.o devtree.o
 obj-y  += signal.o traps.o sys.o troubleshoot.o stacktrace.o disasm.o
 obj-$(CONFIG_ISA_ARCOMPACT)            += entry-compact.o intc-compact.o
 obj-$(CONFIG_ISA_ARCV2)                        += entry-arcv2.o intc-arcv2.o

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index e2c6e43cf8ca31e27af1b6c8630f7a0c590e8b7a..4866f7aa32e65a84c1bc738a9d385e16aa312cd4 100644 (file)
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -282,6 +282,26 @@ config CLKSRC_MPS2
        select CLKSRC_MMIO
        select CLKSRC_OF
 
+config ARC_TIMERS
+       bool "Support for 32-bit TIMERn counters in ARC Cores" if COMPILE_TEST
+       depends on GENERIC_CLOCKEVENTS
+       select CLKSRC_OF
+       help
+         These are legacy 32-bit TIMER0 and TIMER1 counters found on all ARC cores
+         (ARC700 as well as ARC HS38).
+         TIMER0 serves as clockevent while TIMER1 provides clocksource
+
+config ARC_TIMERS_64BIT
+       bool "Support for 64-bit counters in ARC HS38 cores" if COMPILE_TEST
+       depends on GENERIC_CLOCKEVENTS
+       depends on ARC_TIMERS
+       select CLKSRC_OF
+       help
+         This enables 2 different 64-bit timers: RTC (for UP) and GFRC (for SMP)
+         RTC is implemented inside the core, while GFRC sits outside the core in
+         ARConnect IP block. Driver automatically picks one of them for clocksource
+         as appropriate.
+
 config ARM_ARCH_TIMER
        bool
        select CLKSRC_OF if OF

diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index cf87f407f1adbfaab8d485bea93f6ee859d8e3d6..a14111e1f0872d52df6799ea35ff29cdddeb7e36 100644 (file)
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_CLKSRC_TI_32K)   += timer-ti-32k.o
 obj-$(CONFIG_CLKSRC_NPS)       += timer-nps.o
 obj-$(CONFIG_OXNAS_RPS_TIMER)  += timer-oxnas-rps.o
 
+obj-$(CONFIG_ARC_TIMERS)               += arc_timer.o
 obj-$(CONFIG_ARM_ARCH_TIMER)           += arm_arch_timer.o
 obj-$(CONFIG_ARM_GLOBAL_TIMER)         += arm_global_timer.o
 obj-$(CONFIG_ARMV7M_SYSTICK)           += armv7m_systick.o

diff --git a/arch/arc/kernel/time.c b/drivers/clocksource/arc_timer.c
similarity index 90%
rename from arch/arc/kernel/time.c
rename to drivers/clocksource/arc_timer.c
index 94b9cd169374cb0287d23a358edb1cbe3a00675c..a49748d826c0315cf537a0beea7fb40073e410a8 100644 (file)
--- a/arch/arc/kernel/time.c
+++ b/drivers/clocksource/arc_timer.c
@@ -1,32 +1,18 @@
 /*
+ * Copyright (C) 2016-17 Synopsys, Inc. (www.synopsys.com)
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
- *
- * vineetg: Jan 1011
- *  -sched_clock( ) no longer jiffies based. Uses the same clocksource
- *   as gtod
- *
- * Rajeshwarr/Vineetg: Mar 2008
- *  -Implemented CONFIG_GENERIC_TIME (rather deleted arch specific code)
- *   for arch independent gettimeofday()
- *  -Implemented CONFIG_GENERIC_CLOCKEVENTS as base for hrtimers
- *
- * Vineetg: Mar 2008: Forked off from time.c which now is time-jiff.c
  */
 
-/* ARC700 has two 32bit independent prog Timers: TIMER0 and TIMER1
- * Each can programmed to go from @count to @limit and optionally
- * interrupt when that happens.
- * A write to Control Register clears the Interrupt
- *
- * We've designated TIMER0 for events (clockevents)
- * while TIMER1 for free running (clocksource)
+/* ARC700 has two 32bit independent prog Timers: TIMER0 and TIMER1, Each can be
+ * programmed to go from @count to @limit and optionally interrupt.
+ * We've designated TIMER0 for clockevents and TIMER1 for clocksource
  *
- * Newer ARC700 cores have 64bit clk fetching RTSC insn, preferred over TIMER1
- * which however is currently broken
+ * ARCv2 based HS38 cores have RTC (in-core) and GFRC (inside ARConnect/MCIP)
+ * which are suitable for UP and SMP based clocksources respectively
  */
 
 #include <linux/interrupt.h>
@@ -37,7 +23,6 @@
 #include <linux/cpu.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
-#include <asm/irq.h>
 
 #include <soc/arc/timers.h>
 #include <soc/arc/mcip.h>