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, 18 insertions, 1 deletions

diff --git a/arch/sparc/kernel/irq.h b/arch/sparc/kernel/irq.h
index 3f6ca4d55dc4..8b946b1bc3b9 100644
--- a/arch/sparc/kernel/irq.h
+++ b/arch/sparc/kernel/irq.h
@@ -41,15 +41,32 @@ struct sun4m_irq_global {
 extern struct sun4m_irq_percpu __iomem *sun4m_irq_percpu[SUN4M_NCPUS];
 extern struct sun4m_irq_global __iomem *sun4m_irq_global;
 
+/* The following definitions describe the individual platform features: */
+#define FEAT_L10_CLOCKSOURCE (1 << 0) /* L10 timer is used as a clocksource */
+#define FEAT_L10_CLOCKEVENT  (1 << 1) /* L10 timer is used as a clockevent */
+#define FEAT_L14_ONESHOT     (1 << 2) /* L14 timer clockevent can oneshot */
+
 /*
  * Platform specific configuration
  * The individual platforms assign their platform
  * specifics in their init functions.
  */
 struct sparc_config {
-	void (*init_timers)(irq_handler_t);
+	void (*init_timers)(void);
 	unsigned int (*build_device_irq)(struct platform_device *op,
 	                                 unsigned int real_irq);
+
+	/* generic clockevent features - see FEAT_* above */
+	int features;
+
+	/* clock rate used for clock event timer */
+	int clock_rate;
+
+	/* one period for clock source timer */
+	unsigned int cs_period;
+
+	/* function to obtain offsett for cs period */
+	unsigned int (*get_cycles_offset)(void);
 };
 extern struct sparc_config sparc_config;