ARM: OMAP: Timer32K: Re-organize duplicated 32k-timer code
authorKevin Hilman <khilman@mvista.com>
Tue, 13 Nov 2007 07:24:02 +0000 (23:24 -0800)
committerTony Lindgren <tony@atomide.com>
Mon, 14 Apr 2008 16:57:12 +0000 (09:57 -0700)
On OMAP2/3, the gp-timer code can be used for a 32kHz timer simply by
setting the source to be the 32k clock instead of sys_clk.

This patch uses the mach-omap2/timer-gp.c code for 32kHz timer on
OMAP2, moving the logic into mach-omap2/timer-gp.c, and not using
plat-omap/timer32k.c which, for OMAP2, is redundant with the timer-gp
code.

Also, if CONFIG_OMAP_32K_TIMER is enabled, the gptimer-based
clocksource is not used.  Instead the default 32k sync counter is used
as the clocksource (see the clocksource in plat-omap/common.c.)  This
is important for sleep/suspend so there is a valid counter during
sleep.  Note that the suspend/sleep code needs fixing to check for
overflows of this counter.

In addition, the OMAP2/3 details are removed from timer32k.c leaving
that with only OMAP1 specifics.  A follow-up patch will move it from
plat-omap common code to mach-omap1.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
arch/arm/mach-omap2/Makefile
arch/arm/mach-omap2/timer-gp.c
arch/arm/plat-omap/Makefile
arch/arm/plat-omap/timer32k.c

index b05b738..ac343ec 100644 (file)
@@ -4,9 +4,7 @@
 
 # Common support
 obj-y := irq.o id.o io.o sram-fn.o memory.o prcm.o clock.o mux.o devices.o \
-        serial.o gpmc.o
-
-obj-$(CONFIG_OMAP_MPU_TIMER)           += timer-gp.o
+        serial.o gpmc.o timer-gp.o
 
 # Power Management
 obj-$(CONFIG_PM) += pm.o pm-domain.o sleep.o
index 3234dee..78d05f2 100644 (file)
@@ -3,6 +3,11 @@
  *
  * OMAP2 GP timer support.
  *
+ * Update to use new clocksource/clockevent layers
+ * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
+ * Copyright (C) 2007 MontaVista Software, Inc.
+ *
+ * Original driver:
  * Copyright (C) 2005 Nokia Corporation
  * Author: Paul Mundt <paul.mundt@nokia.com>
  *         Juha Yrjölä <juha.yrjola@nokia.com>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/irq.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/mach/time.h>
 #include <asm/arch/dmtimer.h>
 
 static struct omap_dm_timer *gptimer;
-
-static inline void omap2_gp_timer_start(unsigned long load_val)
-{
-       omap_dm_timer_set_load(gptimer, 1, 0xffffffff - load_val);
-       omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW);
-       omap_dm_timer_start(gptimer);
-}
+static struct clock_event_device clockevent_gpt;
 
 static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
 {
-       omap_dm_timer_write_status(gptimer, OMAP_TIMER_INT_OVERFLOW);
-       timer_tick();
+       struct omap_dm_timer *gpt = (struct omap_dm_timer *)dev_id;
+       struct clock_event_device *evt = &clockevent_gpt;
+
+       omap_dm_timer_write_status(gpt, OMAP_TIMER_INT_OVERFLOW);
 
+       evt->event_handler(evt);
        return IRQ_HANDLED;
 }
 
@@ -52,20 +56,138 @@ static struct irqaction omap2_gp_timer_irq = {
        .handler        = omap2_gp_timer_interrupt,
 };
 
-static void __init omap2_gp_timer_init(void)
+static int omap2_gp_timer_set_next_event(unsigned long cycles,
+                                        struct clock_event_device *evt)
 {
-       u32 tick_period;
+       omap_dm_timer_set_load(gptimer, 0, 0xffffffff - cycles);
+       omap_dm_timer_start(gptimer);
+
+       return 0;
+}
+
+static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
+                                   struct clock_event_device *evt)
+{
+       u32 period;
+
+       omap_dm_timer_stop(gptimer);
+
+       switch (mode) {
+       case CLOCK_EVT_MODE_PERIODIC:
+               period = clk_get_rate(omap_dm_timer_get_fclk(gptimer)) / HZ;
+               period -= 1;
+
+               omap_dm_timer_set_load(gptimer, 1, 0xffffffff - period);
+               omap_dm_timer_start(gptimer);
+               break;
+       case CLOCK_EVT_MODE_ONESHOT:
+               break;
+       case CLOCK_EVT_MODE_UNUSED:
+       case CLOCK_EVT_MODE_SHUTDOWN:
+       case CLOCK_EVT_MODE_RESUME:
+               break;
+       }
+}
+
+static struct clock_event_device clockevent_gpt = {
+       .name           = "gp timer",
+       .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+       .shift          = 32,
+       .set_next_event = omap2_gp_timer_set_next_event,
+       .set_mode       = omap2_gp_timer_set_mode,
+};
+
+static void __init omap2_gp_clockevent_init(void)
+{
+       u32 tick_rate;
 
-       omap_dm_timer_init();
        gptimer = omap_dm_timer_request_specific(1);
        BUG_ON(gptimer == NULL);
 
+#if defined(CONFIG_OMAP_32K_TIMER)
+       omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_32_KHZ);
+#else
        omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_SYS_CLK);
-       tick_period = clk_get_rate(omap_dm_timer_get_fclk(gptimer)) / HZ;
-       tick_period -= 1;
+#endif
+       tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gptimer));
 
+       omap2_gp_timer_irq.dev_id = (void *)gptimer;
        setup_irq(omap_dm_timer_get_irq(gptimer), &omap2_gp_timer_irq);
-       omap2_gp_timer_start(tick_period);
+       omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW);
+
+       clockevent_gpt.mult = div_sc(tick_rate, NSEC_PER_SEC,
+                                    clockevent_gpt.shift);
+       clockevent_gpt.max_delta_ns =
+               clockevent_delta2ns(0xffffffff, &clockevent_gpt);
+       clockevent_gpt.min_delta_ns =
+               clockevent_delta2ns(1, &clockevent_gpt);
+
+       clockevent_gpt.cpumask = cpumask_of_cpu(0);
+       clockevents_register_device(&clockevent_gpt);
+}
+
+#ifdef CONFIG_OMAP_32K_TIMER
+/* 
+ * When 32k-timer is enabled, don't use GPTimer for clocksource
+ * instead, just leave default clocksource which uses the 32k
+ * sync counter.  See clocksource setup in see plat-omap/common.c. 
+ */
+
+static inline void __init omap2_gp_clocksource_init(void) {}
+#else
+/*
+ * clocksource
+ */
+static struct omap_dm_timer *gpt_clocksource;
+static cycle_t clocksource_read_cycles(void)
+{
+       return (cycle_t)omap_dm_timer_read_counter(gpt_clocksource);
+}
+
+static struct clocksource clocksource_gpt = {
+       .name           = "gp timer",
+       .rating         = 300,
+       .read           = clocksource_read_cycles,
+       .mask           = CLOCKSOURCE_MASK(32),
+       .shift          = 24,
+       .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/* Setup free-running counter for clocksource */
+static void __init omap2_gp_clocksource_init(void)
+{
+       static struct omap_dm_timer *gpt;
+       u32 tick_rate, tick_period;
+       static char err1[] __initdata = KERN_ERR
+               "%s: failed to request dm-timer\n";
+       static char err2[] __initdata = KERN_ERR
+               "%s: can't register clocksource!\n";
+
+       gpt = omap_dm_timer_request();
+       if (!gpt)
+               printk(err1, clocksource_gpt.name);
+       gpt_clocksource = gpt;
+
+       omap_dm_timer_set_source(gpt, OMAP_TIMER_SRC_SYS_CLK);
+       tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gpt));
+       tick_period = (tick_rate / HZ) - 1;
+
+       omap_dm_timer_set_load(gpt, 1, 0);
+       omap_dm_timer_start(gpt);
+
+       clocksource_gpt.mult =
+               clocksource_khz2mult(tick_rate/1000, clocksource_gpt.shift);
+       if (clocksource_register(&clocksource_gpt))
+               printk(err2, clocksource_gpt.name);
+}
+#endif
+
+static void __init omap2_gp_timer_init(void)
+{
+       omap_dm_timer_init();
+
+       omap2_gp_clockevent_init();
+       omap2_gp_clocksource_init();
 }
 
 struct sys_timer omap_timer = {
index 8f56c25..d91424e 100644 (file)
@@ -9,7 +9,9 @@ obj-m :=
 obj-n :=
 obj-  :=
 
+ifeq ($(CONFIG_ARCH_OMAP1),y)
 obj-$(CONFIG_OMAP_32K_TIMER)   += timer32k.o
+endif
 
 # OCPI interconnect support for 1710, 1610 and 5912
 obj-$(CONFIG_ARCH_OMAP16XX) += ocpi.o
index ea76f19..ce034dc 100644 (file)
@@ -40,6 +40,7 @@
 #include <linux/interrupt.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
+
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/clocksource.h>
@@ -93,8 +94,6 @@ struct sys_timer omap_timer;
 #define JIFFIES_TO_HW_TICKS(nr_jiffies, clock_rate)                    \
                                (((nr_jiffies) * (clock_rate)) / HZ)
 
-#if defined(CONFIG_ARCH_OMAP1)
-
 static inline void omap_32k_timer_write(int val, int reg)
 {
        omap_writew(val, OMAP1_32K_TIMER_BASE + reg);
@@ -120,30 +119,6 @@ static inline void omap_32k_timer_stop(void)
 
 #define omap_32k_timer_ack_irq()
 
-#elif defined(CONFIG_ARCH_OMAP2)
-
-static struct omap_dm_timer *gptimer;
-
-static inline void omap_32k_timer_start(unsigned long load_val)
-{
-       omap_dm_timer_set_load(gptimer, 1, 0xffffffff - load_val);
-       omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW);
-       omap_dm_timer_start(gptimer);
-}
-
-static inline void omap_32k_timer_stop(void)
-{
-       omap_dm_timer_stop(gptimer);
-}
-
-static inline void omap_32k_timer_ack_irq(void)
-{
-       u32 status = omap_dm_timer_read_status(gptimer);
-       omap_dm_timer_write_status(gptimer, status);
-}
-
-#endif
-
 static void omap_32k_timer_set_mode(enum clock_event_mode mode,
                                    struct clock_event_device *evt)
 {
@@ -222,23 +197,6 @@ static struct irqaction omap_32k_timer_irq = {
 
 static __init void omap_init_32k_timer(void)
 {
-       if (cpu_class_is_omap1())
-               setup_irq(INT_OS_TIMER, &omap_32k_timer_irq);
-
-#ifdef CONFIG_ARCH_OMAP2
-       /* REVISIT: Check 24xx TIOCP_CFG settings after idle works */
-       if (cpu_is_omap24xx()) {
-               gptimer = omap_dm_timer_request_specific(1);
-               BUG_ON(gptimer == NULL);
-
-               omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_32_KHZ);
-               setup_irq(omap_dm_timer_get_irq(gptimer), &omap_32k_timer_irq);
-               omap_dm_timer_set_int_enable(gptimer,
-                       OMAP_TIMER_INT_CAPTURE | OMAP_TIMER_INT_OVERFLOW |
-                       OMAP_TIMER_INT_MATCH);
-       }
-#endif
-
        clockevent_32k_timer.mult = div_sc(OMAP_32K_TICKS_PER_SEC,
                                           NSEC_PER_SEC,
                                           clockevent_32k_timer.shift);