sparc32: generic clockevent support

The kernel uses l14 timers as clockevents. l10 timer is used
as clocksource if platform master_l10_counter isn't constantly
zero. The clocksource is continuous, so it's possible to use
high resolution timers. l10 timer is also used as clockevent
on UP configurations.

This realization is for sun4m, sun4d, sun4c, microsparc-IIep
and LEON platforms. The appropriate LEON changes was made by
Konrad Eisele.

In case of sun4m's oneshot mode, profile irq is zeroed in
smp4m_percpu_timer_interrupt(). It is maybe
needless (double, triple etc overflow does nothing).

sun4d is able to have oneshot mode too, but I haven't
any way to test it. So code of its percpu timer handler
is made as much equal to the current code as possible.

The patch is tested on sun4m box in SMP mode by me,
and tested by Konrad on leon in up mode (leon smp
is broken atm - due to other reasons).

Signed-off-by: Tkhai Kirill <tkhai@yandex.ru>
Tested-by: Konrad Eisele <konrad@gaisler.com> [leon up]
[sam: revised patch to provide generic support for leon]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 7 deletions

diff --git a/arch/sparc/kernel/sun4m_irq.c b/arch/sparc/kernel/sun4m_irq.c
index 0d3a2d8cb266..87908a5b1223 100644
--- a/arch/sparc/kernel/sun4m_irq.c
+++ b/arch/sparc/kernel/sun4m_irq.c
@@ -318,9 +318,6 @@ struct sun4m_timer_global {
 
 static struct sun4m_timer_global __iomem *timers_global;
 
-
-unsigned int lvl14_resolution = (((1000000/HZ) + 1) << 10);
-
 static void sun4m_clear_clock_irq(void)
 {
 	sbus_readl(&timers_global->l10_limit);
@@ -369,10 +366,11 @@ void sun4m_clear_profile_irq(int cpu)
 
 static void sun4m_load_profile_irq(int cpu, unsigned int limit)
 {
-	sbus_writel(limit, &timers_percpu[cpu]->l14_limit);
+	unsigned int value = limit ? timer_value(limit) : 0;
+	sbus_writel(value, &timers_percpu[cpu]->l14_limit);
 }
 
-static void __init sun4m_init_timers(irq_handler_t counter_fn)
+static void __init sun4m_init_timers(void)
 {
 	struct device_node *dp = of_find_node_by_name(NULL, "counter");
 	int i, err, len, num_cpu_timers;
@@ -402,13 +400,22 @@ static void __init sun4m_init_timers(irq_handler_t counter_fn)
 	/* Every per-cpu timer works in timer mode */
 	sbus_writel(0x00000000, &timers_global->timer_config);
 
-	sbus_writel((((1000000/HZ) + 1) << 10), &timers_global->l10_limit);
+#ifdef CONFIG_SMP
+	sparc_config.cs_period = SBUS_CLOCK_RATE * 2;  /* 2 seconds */
+	sparc_config.features |= FEAT_L14_ONESHOT;
+#else
+	sparc_config.cs_period = SBUS_CLOCK_RATE / HZ; /* 1/HZ sec  */
+	sparc_config.features |= FEAT_L10_CLOCKEVENT;
+#endif
+	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
+	sbus_writel(timer_value(sparc_config.cs_period),
+	            &timers_global->l10_limit);
 
 	master_l10_counter = &timers_global->l10_count;
 
 	irq = sun4m_build_device_irq(NULL, SUN4M_TIMER_IRQ);
 
-	err = request_irq(irq, counter_fn, IRQF_TIMER, "timer", NULL);
+	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
 	if (err) {
 		printk(KERN_ERR "sun4m_init_timers: Register IRQ error %d.\n",
 			err);
@@ -480,6 +487,7 @@ void __init sun4m_init_IRQ(void)
 
 	sparc_config.init_timers = sun4m_init_timers;
 	sparc_config.build_device_irq = sun4m_build_device_irq;
+	sparc_config.clock_rate       = SBUS_CLOCK_RATE;
 
 #ifdef CONFIG_SMP
 	BTFIXUPSET_CALL(set_cpu_int, sun4m_send_ipi, BTFIXUPCALL_NORM);