ARM: Integrator: convert to generic time support
Russell King [Fri, 15 Jan 2010 18:10:33 +0000 (18:10 +0000)]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig
arch/arm/mach-integrator/common.h
arch/arm/mach-integrator/core.c
arch/arm/mach-integrator/integrator_ap.c
arch/arm/mach-integrator/integrator_cp.c

index c5408bf..7698d87 100644 (file)
@@ -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.
 
index 609c49d..7dc24bb 100644 (file)
@@ -1,2 +1 @@
 extern void integrator_time_init(unsigned long, unsigned int);
-extern unsigned long integrator_gettimeoffset(void);
index 096f899..87c6f98 100644 (file)
@@ -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;
 
index 018c32d..cfb718f 100644 (file)
@@ -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")
index c66e8fa..3e84732 100644 (file)
@@ -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")