summaryrefslogtreecommitdiff
path: root/arch/arm/mach-netx/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-netx/time.c')
-rw-r--r--arch/arm/mach-netx/time.c150
1 files changed, 150 insertions, 0 deletions
diff --git a/arch/arm/mach-netx/time.c b/arch/arm/mach-netx/time.c
new file mode 100644
index 000000000..5fb2a590e
--- /dev/null
+++ b/arch/arm/mach-netx/time.c
@@ -0,0 +1,150 @@
+/*
+ * arch/arm/mach-netx/time.c
+ *
+ * Copyright (c) 2005 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/io.h>
+
+#include <mach/hardware.h>
+#include <asm/mach/time.h>
+#include <mach/netx-regs.h>
+
+#define NETX_CLOCK_FREQ 100000000
+#define NETX_LATCH DIV_ROUND_CLOSEST(NETX_CLOCK_FREQ, HZ)
+
+#define TIMER_CLOCKEVENT 0
+#define TIMER_CLOCKSOURCE 1
+
+static void netx_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *clk)
+{
+ u32 tmode;
+
+ /* disable timer */
+ writel(0, NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKEVENT));
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ writel(NETX_LATCH, NETX_GPIO_COUNTER_MAX(TIMER_CLOCKEVENT));
+ tmode = NETX_GPIO_COUNTER_CTRL_RST_EN |
+ NETX_GPIO_COUNTER_CTRL_IRQ_EN |
+ NETX_GPIO_COUNTER_CTRL_RUN;
+ break;
+
+ case CLOCK_EVT_MODE_ONESHOT:
+ writel(0, NETX_GPIO_COUNTER_MAX(TIMER_CLOCKEVENT));
+ tmode = NETX_GPIO_COUNTER_CTRL_IRQ_EN |
+ NETX_GPIO_COUNTER_CTRL_RUN;
+ break;
+
+ default:
+ WARN(1, "%s: unhandled mode %d\n", __func__, mode);
+ /* fall through */
+
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_RESUME:
+ tmode = 0;
+ break;
+ }
+
+ writel(tmode, NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKEVENT));
+}
+
+static int netx_set_next_event(unsigned long evt,
+ struct clock_event_device *clk)
+{
+ writel(0 - evt, NETX_GPIO_COUNTER_CURRENT(TIMER_CLOCKEVENT));
+ return 0;
+}
+
+static struct clock_event_device netx_clockevent = {
+ .name = "netx-timer" __stringify(TIMER_CLOCKEVENT),
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = netx_set_next_event,
+ .set_mode = netx_set_mode,
+};
+
+/*
+ * IRQ handler for the timer
+ */
+static irqreturn_t
+netx_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &netx_clockevent;
+
+ /* acknowledge interrupt */
+ writel(COUNTER_BIT(0), NETX_GPIO_IRQ);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction netx_timer_irq = {
+ .name = "NetX Timer Tick",
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = netx_timer_interrupt,
+};
+
+/*
+ * Set up timer interrupt
+ */
+void __init netx_timer_init(void)
+{
+ /* disable timer initially */
+ writel(0, NETX_GPIO_COUNTER_CTRL(0));
+
+ /* Reset the timer value to zero */
+ writel(0, NETX_GPIO_COUNTER_CURRENT(0));
+
+ writel(NETX_LATCH, NETX_GPIO_COUNTER_MAX(0));
+
+ /* acknowledge interrupt */
+ writel(COUNTER_BIT(0), NETX_GPIO_IRQ);
+
+ /* Enable the interrupt in the specific timer
+ * register and start timer
+ */
+ writel(COUNTER_BIT(0), NETX_GPIO_IRQ_ENABLE);
+ writel(NETX_GPIO_COUNTER_CTRL_IRQ_EN | NETX_GPIO_COUNTER_CTRL_RUN,
+ NETX_GPIO_COUNTER_CTRL(0));
+
+ setup_irq(NETX_IRQ_TIMER0, &netx_timer_irq);
+
+ /* Setup timer one for clocksource */
+ writel(0, NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKSOURCE));
+ writel(0, NETX_GPIO_COUNTER_CURRENT(TIMER_CLOCKSOURCE));
+ writel(0xffffffff, NETX_GPIO_COUNTER_MAX(TIMER_CLOCKSOURCE));
+
+ writel(NETX_GPIO_COUNTER_CTRL_RUN,
+ NETX_GPIO_COUNTER_CTRL(TIMER_CLOCKSOURCE));
+
+ clocksource_mmio_init(NETX_GPIO_COUNTER_CURRENT(TIMER_CLOCKSOURCE),
+ "netx_timer", NETX_CLOCK_FREQ, 200, 32, clocksource_mmio_readl_up);
+
+ /* with max_delta_ns >= delta2ns(0x800) the system currently runs fine.
+ * Adding some safety ... */
+ netx_clockevent.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&netx_clockevent, NETX_CLOCK_FREQ,
+ 0xa00, 0xfffffffe);
+}