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>

4 files changed, 30 insertions, 3 deletions

diff --git a/arch/sparc/include/asm/cpudata_32.h b/arch/sparc/include/asm/cpudata_32.h
index a4c5a938b93..0300d94c25b 100644
--- a/arch/sparc/include/asm/cpudata_32.h
+++ b/arch/sparc/include/asm/cpudata_32.h
@@ -14,7 +14,6 @@
 typedef struct {
 	unsigned long udelay_val;
 	unsigned long clock_tick;
-	unsigned int multiplier;
 	unsigned int counter;
 #ifdef CONFIG_SMP
 	unsigned int irq_resched_count;
diff --git a/arch/sparc/include/asm/leon.h b/arch/sparc/include/asm/leon.h
index a4e457f003e..cf35a26454c 100644
--- a/arch/sparc/include/asm/leon.h
+++ b/arch/sparc/include/asm/leon.h
@@ -323,7 +323,7 @@ extern void leon_update_virq_handling(unsigned int virq,
 			      const char *name, int do_ack);
 extern void leon_clear_clock_irq(void);
 extern void leon_load_profile_irq(int cpu, unsigned int limit);
-extern void leon_init_timers(irq_handler_t counter_fn);
+extern void leon_init_timers(void);
 extern void leon_clear_clock_irq(void);
 extern void leon_load_profile_irq(int cpu, unsigned int limit);
 extern void leon_trans_init(struct device_node *dp);
diff --git a/arch/sparc/include/asm/timer_32.h b/arch/sparc/include/asm/timer_32.h
index 1a91e11dd10..e6e66678f47 100644
--- a/arch/sparc/include/asm/timer_32.h
+++ b/arch/sparc/include/asm/timer_32.h
@@ -8,11 +8,40 @@
 #ifndef _SPARC_TIMER_H
 #define _SPARC_TIMER_H
 
+#include <linux/clocksource.h>
+#include <linux/irqreturn.h>
+
+#include <asm-generic/percpu.h>
+
 #include <asm/cpu_type.h>  /* For SUN4M_NCPUS */
 #include <asm/btfixup.h>
 
+#define SBUS_CLOCK_RATE   2000000 /* 2MHz */
+#define TIMER_VALUE_SHIFT 9
+#define TIMER_VALUE_MASK  0x3fffff
+#define TIMER_LIMIT_BIT   (1 << 31)  /* Bit 31 in Counter-Timer register */
+
+/* The counter timer register has the value offset by 9 bits.
+ * From sun4m manual:
+ * When a counter reaches the value in the corresponding limit register,
+ * the Limit bit is set and the counter is set to 500 nS (i.e. 0x00000200).
+ *
+ * To compensate for this add one to the value.
+ */
+static inline unsigned int timer_value(unsigned int value)
+{
+	return (value + 1) << TIMER_VALUE_SHIFT;
+}
+
 extern __volatile__ unsigned int *master_l10_counter;
 
+extern irqreturn_t notrace timer_interrupt(int dummy, void *dev_id);
+
+#ifdef CONFIG_SMP
+DECLARE_PER_CPU(struct clock_event_device, sparc32_clockevent);
+extern void register_percpu_ce(int cpu);
+#endif
+
 /* FIXME: Make do_[gs]ettimeofday btfixup calls */
 struct timespec;
 BTFIXUPDEF_CALL(int, bus_do_settimeofday, struct timespec *tv)
diff --git a/arch/sparc/include/asm/timex_32.h b/arch/sparc/include/asm/timex_32.h
index a254750e4c0..b6ccdb0d6f7 100644
--- a/arch/sparc/include/asm/timex_32.h
+++ b/arch/sparc/include/asm/timex_32.h
@@ -12,5 +12,4 @@
 typedef unsigned long cycles_t;
 #define get_cycles()	(0)
 
-extern u32 (*do_arch_gettimeoffset)(void);
 #endif