ARM: Integrator: convert to generic time support

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

5 files changed, 31 insertions, 35 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c5408bf1bf43..7698d8705a8f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -241,6 +241,7 @@ config ARCH_INTEGRATOR
         select HAVE_CLK
         select COMMON_CLKDEV
         select ICST525
+        select GENERIC_TIME
         help
           Support for ARM's Integrator platform.
 
diff --git a/arch/arm/mach-integrator/common.h b/arch/arm/mach-integrator/common.h
index 609c49de3d47..7dc24bb9bdc1 100644
--- a/arch/arm/mach-integrator/common.h
+++ b/arch/arm/mach-integrator/common.h
@@ -1,2 +1 @@
 extern void integrator_time_init(unsigned long, unsigned int);
-extern unsigned long integrator_gettimeoffset(void);
diff --git a/arch/arm/mach-integrator/core.c b/arch/arm/mach-integrator/core.c
index 096f899625f8..87c6f980944d 100644
--- a/arch/arm/mach-integrator/core.c
+++ b/arch/arm/mach-integrator/core.c
@@ -19,6 +19,7 @@
 #include <linux/termios.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/serial.h>
+#include <linux/clocksource.h>
 #include <linux/io.h>
 
 #include <asm/clkdev.h>
@@ -225,7 +226,6 @@ EXPORT_SYMBOL(cm_control);
 #define TIMER0_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000000)
 #define TIMER1_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000100)
 #define TIMER2_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000200)
-#define VA_IC_BASE     IO_ADDRESS(INTEGRATOR_IC_BASE) 
 
 /*
  * How long is the timer interval?
@@ -241,42 +241,38 @@ EXPORT_SYMBOL(cm_control);
 
 static unsigned long timer_reload;
 
-/*
- * Returns number of ms since last clock interrupt.  Note that interrupts
- * will have been disabled by do_gettimeoffset()
- */
-unsigned long integrator_gettimeoffset(void)
+static void __iomem * const clksrc_base = (void __iomem *)TIMER2_VA_BASE;
+
+static cycle_t timersp_read(struct clocksource *cs)
 {
-        unsigned long ticks1, ticks2, status;
+        return ~(readl(clksrc_base + TIMER_VALUE) & 0xffff);
+}
 
-        /*
-         * Get the current number of ticks.  Note that there is a race
-         * condition between us reading the timer and checking for
-         * an interrupt.  We get around this by ensuring that the
-         * counter has not reloaded between our two reads.
-         */
-        ticks2 = readl(TIMER1_VA_BASE + TIMER_VALUE) & 0xffff;
-        do {
-                ticks1 = ticks2;
-                status = __raw_readl(VA_IC_BASE + IRQ_RAW_STATUS);
-                ticks2 = readl(TIMER1_VA_BASE + TIMER_VALUE) & 0xffff;
-        } while (ticks2 > ticks1);
+static struct clocksource clocksource_timersp = {
+        .name           = "timer2",
+        .rating         = 200,
+        .read           = timersp_read,
+        .mask           = CLOCKSOURCE_MASK(16),
+        .shift          = 16,
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
 
-        /*
-         * Number of ticks since last interrupt.
-         */
-        ticks1 = timer_reload - ticks2;
+static void integrator_clocksource_init(u32 khz)
+{
+        struct clocksource *cs = &clocksource_timersp;
+        void __iomem *base = clksrc_base;
+        u32 ctrl = TIMER_CTRL_ENABLE;
 
-        /*
-         * Interrupt pending?  If so, we've reloaded once already.
-         */
-        if (status & (1 << IRQ_TIMERINT1))
-                ticks1 += timer_reload;
+        if (khz >= 1500) {
+                khz /= 16;
+                ctrl = TIMER_CTRL_DIV16;
+        }
 
-        /*
-         * Convert the ticks to usecs
-         */
-        return TICKS2USECS(ticks1);
+        writel(ctrl, base + TIMER_CTRL);
+        writel(0xffff, base + TIMER_LOAD);
+
+        cs->mult = clocksource_khz2mult(khz, cs->shift);
+        clocksource_register(cs);
 }
 
 /*
@@ -308,6 +304,8 @@ void __init integrator_time_init(unsigned long reload, unsigned int ctrl)
 {
         unsigned int timer_ctrl = TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC;
 
+        integrator_clocksource_init(reload * HZ / 1000);
+
         timer_reload = reload;
         timer_ctrl |= ctrl;
 
diff --git a/arch/arm/mach-integrator/integrator_ap.c b/arch/arm/mach-integrator/integrator_ap.c
index 018c32da4c86..cfb718fe31a8 100644
--- a/arch/arm/mach-integrator/integrator_ap.c
+++ b/arch/arm/mach-integrator/integrator_ap.c
@@ -342,7 +342,6 @@ static void __init ap_init_timer(void)
 
 static struct sys_timer ap_timer = {
         .init           = ap_init_timer,
-        .offset         = integrator_gettimeoffset,
 };
 
 MACHINE_START(INTEGRATOR, "ARM-Integrator")
diff --git a/arch/arm/mach-integrator/integrator_cp.c b/arch/arm/mach-integrator/integrator_cp.c
index c66e8fa0e622..3e84732163ea 100644
--- a/arch/arm/mach-integrator/integrator_cp.c
+++ b/arch/arm/mach-integrator/integrator_cp.c
@@ -577,7 +577,6 @@ static void __init intcp_timer_init(void)
 
 static struct sys_timer cp_timer = {
         .init           = intcp_timer_init,
-        .offset         = integrator_gettimeoffset,
 };
 
 MACHINE_START(CINTEGRATOR, "ARM-IntegratorCP")