*
* 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>
+ * 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 Texas Instruments, Inc.
+ * 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
#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>
+#include <mach/dmtimer.h>
+#include <asm/localtimer.h>
-static struct omap_dm_timer *gptimer;
+/* MAX_GPTIMER_ID: number of GPTIMERs on the chip */
+#define MAX_GPTIMER_ID 12
-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 omap_dm_timer *gptimer;
+static struct clock_event_device clockevent_gpt;
+static u8 __initdata gptimer_id = 1;
+static u8 __initdata inited;
static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
{
- write_seqlock(&xtime_lock);
-
- 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;
- write_sequnlock(&xtime_lock);
+ 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,
+ .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.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_start(gptimer, 0, 0xffffffff - cycles);
- omap_dm_timer_init();
- gptimer = omap_dm_timer_request_specific(1);
+ 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;
+ if (cpu_is_omap44xx())
+ period = 0xff; /* FIXME: */
+ 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;
+
+ inited = 1;
+
+ gptimer = omap_dm_timer_request_specific(gptimer_id);
BUG_ON(gptimer == NULL);
- 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;
+#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));
+ if (cpu_is_omap44xx())
+ /* Assuming 32kHz clk is driving GPT1 */
+ tick_rate = 32768; /* FIXME: */
+
+ 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);
- 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(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 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(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),
+ .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_start(gpt, 1, 0);
+
+ 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)
+{
+#ifdef CONFIG_LOCAL_TIMERS
+ twd_base = IO_ADDRESS(OMAP44XX_LOCAL_TWD_BASE);
+#endif
+ omap_dm_timer_init();
+
+ omap2_gp_clockevent_init();
+ omap2_gp_clocksource_init();
}
struct sys_timer omap_timer = {