initial_commit

1 files changed, 266 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/timer-gp.c b/arch/arm/mach-omap2/timer-gp.c
new file mode 100644
index 00000000..3b9cf85f
--- /dev/null
+++ b/arch/arm/mach-omap2/timer-gp.c
@@ -0,0 +1,266 @@
+/*
+ * linux/arch/arm/mach-omap2/timer-gp.c
+ *
+ * OMAP2 GP timer support.
+ *
+ * Copyright (C) 2009 Nokia Corporation
+ *
+ * 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>
+ * OMAP Dual-mode timer framework support by Timo Teras
+ *
+ * Some parts based off of TI's 24xx code:
+ *
+ * Copyright (C) 2004-2009 Texas Instruments, Inc.
+ *
+ * Roughly modelled after the OMAP1 MPU timer code.
+ * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * 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/time.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#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 <plat/dmtimer.h>
+#include <asm/localtimer.h>
+#include <asm/sched_clock.h>
+#include <plat/common.h>
+#include <plat/omap_hwmod.h>
+
+#include "timer-gp.h"
+
+
+/* MAX_GPTIMER_ID: number of GPTIMERs on the chip */
+#define MAX_GPTIMER_ID		12
+
+static struct omap_dm_timer *gptimer;
+static struct clock_event_device clockevent_gpt;
+static u8 __initdata gptimer_id = 1;
+static u8 __initdata inited;
+struct omap_dm_timer *gptimer_wakeup;
+
+static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
+{
+	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;
+}
+
+static struct irqaction omap2_gp_timer_irq = {
+	.name		= "gp timer",
+	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= omap2_gp_timer_interrupt,
+};
+
+static int omap2_gp_timer_set_next_event(unsigned long cycles,
+					 struct clock_event_device *evt)
+{
+	omap_dm_timer_set_load_start(gptimer, 0, 0xffffffff - cycles);
+
+	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_start(gptimer, 1, 0xffffffff - period);
+		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,
+};
+
+/**
+ * omap2_gp_clockevent_set_gptimer - set which GPTIMER is used for clockevents
+ * @id: GPTIMER to use (1..MAX_GPTIMER_ID)
+ *
+ * Define the GPTIMER that the system should use for the tick timer.
+ * Meant to be called from board-*.c files in the event that GPTIMER1, the
+ * default, is unsuitable.  Returns -EINVAL on error or 0 on success.
+ */
+int __init omap2_gp_clockevent_set_gptimer(u8 id)
+{
+	if (id < 1 || id > MAX_GPTIMER_ID)
+		return -EINVAL;
+
+	BUG_ON(inited);
+
+	gptimer_id = id;
+
+	return 0;
+}
+
+static void __init omap2_gp_clockevent_init(void)
+{
+	u32 tick_rate;
+	int src;
+	char clockevent_hwmod_name[8]; /* 8 = sizeof("timerXX0") */
+
+	inited = 1;
+
+	sprintf(clockevent_hwmod_name, "timer%d", gptimer_id);
+	omap_hwmod_setup_one(clockevent_hwmod_name);
+
+	gptimer = omap_dm_timer_request_specific(gptimer_id);
+	BUG_ON(gptimer == NULL);
+	gptimer_wakeup = gptimer;
+
+#if defined(CONFIG_OMAP_32K_TIMER)
+	src = OMAP_TIMER_SRC_32_KHZ;
+#else
+	src = OMAP_TIMER_SRC_SYS_CLK;
+	WARN(gptimer_id == 12, "WARNING: GPTIMER12 can only use the "
+	     "secure 32KiHz clock source\n");
+#endif
+
+	if (gptimer_id != 12)
+		WARN(IS_ERR_VALUE(omap_dm_timer_set_source(gptimer, src)),
+		     "timer-gp: omap_dm_timer_set_source() failed\n");
+
+	tick_rate = clk_get_rate(omap_dm_timer_get_fclk(gptimer));
+
+	pr_info("OMAP clockevent source: GPTIMER%d at %u Hz\n",
+		gptimer_id, tick_rate);
+
+	omap2_gp_timer_irq.dev_id = (void *)gptimer;
+	setup_irq(omap_dm_timer_get_irq(gptimer), &omap2_gp_timer_irq);
+	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(3, &clockevent_gpt);
+		/* Timer internal resynch latency. */
+
+	clockevent_gpt.cpumask = cpumask_of(0);
+	clockevents_register_device(&clockevent_gpt);
+}
+
+/* Clocksource code */
+
+#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 plat-omap/counter_32k.c
+ */
+
+static void __init omap2_gp_clocksource_init(void)
+{
+	omap_init_clocksource_32k();
+}
+
+#else
+/*
+ * clocksource
+ */
+static DEFINE_CLOCK_DATA(cd);
+static struct omap_dm_timer *gpt_clocksource;
+static cycle_t clocksource_read_cycles(struct clocksource *cs)
+{
+	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),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void notrace dmtimer_update_sched_clock(void)
+{
+	u32 cyc;
+
+	cyc = omap_dm_timer_read_counter(gpt_clocksource);
+
+	update_sched_clock(&cd, cyc, (u32)~0);
+}
+
+/* Setup free-running counter for clocksource */
+static void __init omap2_gp_clocksource_init(void)
+{
+	static struct omap_dm_timer *gpt;
+	u32 tick_rate;
+	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));
+
+	omap_dm_timer_set_load_start(gpt, 1, 0);
+
+	init_sched_clock(&cd, dmtimer_update_sched_clock, 32, tick_rate);
+
+	if (clocksource_register_hz(&clocksource_gpt, tick_rate))
+		printk(err2, clocksource_gpt.name);
+}
+#endif
+
+static void __init omap2_gp_timer_init(void)
+{
+#ifdef CONFIG_LOCAL_TIMERS
+	if (cpu_is_omap44xx()) {
+		twd_base = ioremap(OMAP44XX_LOCAL_TWD_BASE, SZ_256);
+		BUG_ON(!twd_base);
+	}
+#endif
+	omap_dm_timer_init();
+
+	omap2_gp_clockevent_init();
+	omap2_gp_clocksource_init();
+}
+
+struct sys_timer omap_timer = {
+	.init	= omap2_gp_timer_init,
+};