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authorMichal Simek <monstr@monstr.eu>2009-03-27 14:25:49 +0100
committerMichal Simek <monstr@monstr.eu>2009-03-27 14:25:49 +0100
commiteedbdab99fffb8ed71cac75a722088b8ace2583c (patch)
tree6f6b11f46a5d1b011a12dd61421cd1f2b10af237 /arch/microblaze/kernel/timer.c
parent3be100114a352bb4b0eee5b6a847cf4f34ce28b1 (diff)
downloadtalos-op-linux-eedbdab99fffb8ed71cac75a722088b8ace2583c.tar.gz
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microblaze_v8: Interrupt handling and timer support
Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com> Acked-by: John Linn <john.linn@xilinx.com> Acked-by: John Williams <john.williams@petalogix.com> Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/kernel/timer.c')
-rw-r--r--arch/microblaze/kernel/timer.c262
1 files changed, 262 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/timer.c b/arch/microblaze/kernel/timer.c
new file mode 100644
index 000000000000..05a497eefd78
--- /dev/null
+++ b/arch/microblaze/kernel/timer.c
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2007-2009 PetaLogix
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/interrupt.h>
+#include <linux/profile.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/io.h>
+#include <asm/cpuinfo.h>
+#include <asm/setup.h>
+#include <asm/prom.h>
+#include <asm/irq.h>
+#include <asm/system.h>
+
+#ifdef CONFIG_SELFMOD_TIMER
+#include <asm/selfmod.h>
+#define TIMER_BASE BARRIER_BASE_ADDR
+#else
+static unsigned int timer_baseaddr;
+#define TIMER_BASE timer_baseaddr
+#endif
+
+#define TCSR0 (0x00)
+#define TLR0 (0x04)
+#define TCR0 (0x08)
+#define TCSR1 (0x10)
+#define TLR1 (0x14)
+#define TCR1 (0x18)
+
+#define TCSR_MDT (1<<0)
+#define TCSR_UDT (1<<1)
+#define TCSR_GENT (1<<2)
+#define TCSR_CAPT (1<<3)
+#define TCSR_ARHT (1<<4)
+#define TCSR_LOAD (1<<5)
+#define TCSR_ENIT (1<<6)
+#define TCSR_ENT (1<<7)
+#define TCSR_TINT (1<<8)
+#define TCSR_PWMA (1<<9)
+#define TCSR_ENALL (1<<10)
+
+static inline void microblaze_timer0_stop(void)
+{
+ out_be32(TIMER_BASE + TCSR0, in_be32(TIMER_BASE + TCSR0) & ~TCSR_ENT);
+}
+
+static inline void microblaze_timer0_start_periodic(unsigned long load_val)
+{
+ if (!load_val)
+ load_val = 1;
+ out_be32(TIMER_BASE + TLR0, load_val); /* loading value to timer reg */
+
+ /* load the initial value */
+ out_be32(TIMER_BASE + TCSR0, TCSR_LOAD);
+
+ /* see timer data sheet for detail
+ * !ENALL - don't enable 'em all
+ * !PWMA - disable pwm
+ * TINT - clear interrupt status
+ * ENT- enable timer itself
+ * EINT - enable interrupt
+ * !LOAD - clear the bit to let go
+ * ARHT - auto reload
+ * !CAPT - no external trigger
+ * !GENT - no external signal
+ * UDT - set the timer as down counter
+ * !MDT0 - generate mode
+ */
+ out_be32(TIMER_BASE + TCSR0,
+ TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT);
+}
+
+static inline void microblaze_timer0_start_oneshot(unsigned long load_val)
+{
+ if (!load_val)
+ load_val = 1;
+ out_be32(TIMER_BASE + TLR0, load_val); /* loading value to timer reg */
+
+ /* load the initial value */
+ out_be32(TIMER_BASE + TCSR0, TCSR_LOAD);
+
+ out_be32(TIMER_BASE + TCSR0,
+ TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT);
+}
+
+static int microblaze_timer_set_next_event(unsigned long delta,
+ struct clock_event_device *dev)
+{
+ pr_debug("%s: next event, delta %x\n", __func__, (u32)delta);
+ microblaze_timer0_start_oneshot(delta);
+ return 0;
+}
+
+static void microblaze_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ printk(KERN_INFO "%s: periodic\n", __func__);
+ microblaze_timer0_start_periodic(cpuinfo.freq_div_hz);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ printk(KERN_INFO "%s: oneshot\n", __func__);
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ printk(KERN_INFO "%s: unused\n", __func__);
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ printk(KERN_INFO "%s: shutdown\n", __func__);
+ microblaze_timer0_stop();
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ printk(KERN_INFO "%s: resume\n", __func__);
+ break;
+ }
+}
+
+static struct clock_event_device clockevent_microblaze_timer = {
+ .name = "microblaze_clockevent",
+ .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+ .shift = 24,
+ .rating = 300,
+ .set_next_event = microblaze_timer_set_next_event,
+ .set_mode = microblaze_timer_set_mode,
+};
+
+static inline void timer_ack(void)
+{
+ out_be32(TIMER_BASE + TCSR0, in_be32(TIMER_BASE + TCSR0));
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &clockevent_microblaze_timer;
+#ifdef CONFIG_HEART_BEAT
+ heartbeat();
+#endif
+ timer_ack();
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction timer_irqaction = {
+ .handler = timer_interrupt,
+ .flags = IRQF_DISABLED | IRQF_TIMER,
+ .name = "timer",
+ .dev_id = &clockevent_microblaze_timer,
+};
+
+static __init void microblaze_clockevent_init(void)
+{
+ clockevent_microblaze_timer.mult =
+ div_sc(cpuinfo.cpu_clock_freq, NSEC_PER_SEC,
+ clockevent_microblaze_timer.shift);
+ clockevent_microblaze_timer.max_delta_ns =
+ clockevent_delta2ns((u32)~0, &clockevent_microblaze_timer);
+ clockevent_microblaze_timer.min_delta_ns =
+ clockevent_delta2ns(1, &clockevent_microblaze_timer);
+ clockevent_microblaze_timer.cpumask = cpumask_of(0);
+ clockevents_register_device(&clockevent_microblaze_timer);
+}
+
+static cycle_t microblaze_read(void)
+{
+ /* reading actual value of timer 1 */
+ return (cycle_t) (in_be32(TIMER_BASE + TCR1));
+}
+
+static struct clocksource clocksource_microblaze = {
+ .name = "microblaze_clocksource",
+ .rating = 300,
+ .read = microblaze_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .shift = 24, /* I can shift it */
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init microblaze_clocksource_init(void)
+{
+ clocksource_microblaze.mult =
+ clocksource_hz2mult(cpuinfo.cpu_clock_freq,
+ clocksource_microblaze.shift);
+ if (clocksource_register(&clocksource_microblaze))
+ panic("failed to register clocksource");
+
+ /* stop timer1 */
+ out_be32(TIMER_BASE + TCSR1, in_be32(TIMER_BASE + TCSR1) & ~TCSR_ENT);
+ /* start timer1 - up counting without interrupt */
+ out_be32(TIMER_BASE + TCSR1, TCSR_TINT|TCSR_ENT|TCSR_ARHT);
+ return 0;
+}
+
+void __init time_init(void)
+{
+ u32 irq, i = 0;
+ u32 timer_num = 1;
+ struct device_node *timer = NULL;
+#ifdef CONFIG_SELFMOD_TIMER
+ unsigned int timer_baseaddr = 0;
+ int arr_func[] = {
+ (int)&microblaze_read,
+ (int)&timer_interrupt,
+ (int)&microblaze_clocksource_init,
+ (int)&microblaze_timer_set_mode,
+ (int)&microblaze_timer_set_next_event,
+ 0
+ };
+#endif
+ char *timer_list[] = {
+ "xlnx,xps-timer-1.00.a",
+ "xlnx,opb-timer-1.00.b",
+ "xlnx,opb-timer-1.00.a",
+ NULL
+ };
+
+ for (i = 0; timer_list[i] != NULL; i++) {
+ timer = of_find_compatible_node(NULL, NULL, timer_list[i]);
+ if (timer)
+ break;
+ }
+
+ timer_baseaddr = *(int *) of_get_property(timer, "reg", NULL);
+ timer_baseaddr = (unsigned long) ioremap(timer_baseaddr, PAGE_SIZE);
+ irq = *(int *) of_get_property(timer, "interrupts", NULL);
+ timer_num =
+ *(int *) of_get_property(timer, "xlnx,one-timer-only", NULL);
+ if (timer_num) {
+ printk(KERN_EMERG "Please enable two timers in HW\n");
+ BUG();
+ }
+
+#ifdef CONFIG_SELFMOD_TIMER
+ selfmod_function((int *) arr_func, timer_baseaddr);
+#endif
+ printk(KERN_INFO "%s #0 at 0x%08x, irq=%d\n",
+ timer_list[i], timer_baseaddr, irq);
+
+ cpuinfo.freq_div_hz = cpuinfo.cpu_clock_freq / HZ;
+
+ setup_irq(irq, &timer_irqaction);
+#ifdef CONFIG_HEART_BEAT
+ setup_heartbeat();
+#endif
+ microblaze_clocksource_init();
+ microblaze_clockevent_init();
+}
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