[ARM] 3580/1: AT91RM9200 Timer suspend/resume support

Patch from Andrew Victor

Added suspend/resume support for the AT91RM9200 timer.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 30 insertions, 14 deletions

diff --git a/arch/arm/mach-at91rm9200/time.c b/arch/arm/mach-at91rm9200/time.c
index 36798a8d532a..fc2d7d5e4637 100644
--- a/arch/arm/mach-at91rm9200/time.c
+++ b/arch/arm/mach-at91rm9200/time.c
@@ -90,6 +90,20 @@ static struct irqaction at91rm9200_timer_irq = {
         .handler        = at91rm9200_timer_interrupt
 };
 
+void at91rm9200_timer_reset(void)
+{
+        last_crtr = 0;
+
+        /* Real time counter incremented every 30.51758 microseconds */
+        at91_sys_write(AT91_ST_RTMR, 1);
+
+        /* Set Period Interval timer */
+        at91_sys_write(AT91_ST_PIMR, LATCH);
+
+        /* Enable Period Interval Timer interrupt */
+        at91_sys_write(AT91_ST_IER, AT91_ST_PITS);
+}
+
 /*
  * Set up timer interrupt.
  */
@@ -99,28 +113,30 @@ void __init at91rm9200_timer_init(void)
         at91_sys_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS);
         (void) at91_sys_read(AT91_ST_SR);       /* Clear any pending interrupts */
 
-        /*
-         * Make IRQs happen for the system timer.
-         */
+        /* Make IRQs happen for the system timer */
         setup_irq(AT91_ID_SYS, &at91rm9200_timer_irq);
 
-        /* Set initial alarm to 0 */
-        at91_sys_write(AT91_ST_RTAR, 0);
-
-        /* Real time counter incremented every 30.51758 microseconds */
-        at91_sys_write(AT91_ST_RTMR, 1);
-
-        /* Set Period Interval timer */
-        at91_sys_write(AT91_ST_PIMR, LATCH);
-
         /* Change the kernel's 'tick' value to 10009 usec. (the default is 10000) */
         tick_usec = (LATCH * 1000000) / CLOCK_TICK_RATE;
 
-        /* Enable Period Interval Timer interrupt */
-        at91_sys_write(AT91_ST_IER, AT91_ST_PITS);
+        /* Initialize and enable the timer interrupt */
+        at91rm9200_timer_reset();
+}
+
+#ifdef CONFIG_PM
+static void at91rm9200_timer_suspend(void)
+{
+        /* disable Period Interval Timer interrupt */
+        at91_sys_write(AT91_ST_IDR, AT91_ST_PITS);
 }
+#else
+#define at91rm9200_timer_suspend        NULL
+#endif
 
 struct sys_timer at91rm9200_timer = {
         .init           = at91rm9200_timer_init,
         .offset         = at91rm9200_gettimeoffset,
+        .suspend        = at91rm9200_timer_suspend,
+        .resume         = at91rm9200_timer_reset,
 };
+