summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-pnx4008/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-pnx4008/time.c')
-rw-r--r--arch/arm/mach-pnx4008/time.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/arm/mach-pnx4008/time.c b/arch/arm/mach-pnx4008/time.c
new file mode 100644
index 00000000000..4ce68069852
--- /dev/null
+++ b/arch/arm/mach-pnx4008/time.c
@@ -0,0 +1,141 @@
+/*
+ * arch/arm/mach-pnx4008/time.c
+ *
+ * PNX4008 Timers
+ *
+ * Authors: Vitaly Wool, Dmitry Chigirev, Grigory Tolstolytkin <source@mvista.com>
+ *
+ * 2005 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+
+#include <asm/system.h>
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/leds.h>
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+#include <asm/mach/time.h>
+
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <asm/errno.h>
+
+/*! Note: all timers are UPCOUNTING */
+
+/*!
+ * Returns number of us since last clock interrupt. Note that interrupts
+ * will have been disabled by do_gettimeoffset()
+ */
+static unsigned long pnx4008_gettimeoffset(void)
+{
+ u32 ticks_to_match =
+ __raw_readl(HSTIM_MATCH0) - __raw_readl(HSTIM_COUNTER);
+ u32 elapsed = LATCH - ticks_to_match;
+ return (elapsed * (tick_nsec / 1000)) / LATCH;
+}
+
+/*!
+ * IRQ handler for the timer
+ */
+static irqreturn_t pnx4008_timer_interrupt(int irq, void *dev_id,
+ struct pt_regs *regs)
+{
+ if (__raw_readl(HSTIM_INT) & MATCH0_INT) {
+
+ write_seqlock(&xtime_lock);
+
+ do {
+ timer_tick(regs);
+
+ /*
+ * this algorithm takes care of possible delay
+ * for this interrupt handling longer than a normal
+ * timer period
+ */
+ __raw_writel(__raw_readl(HSTIM_MATCH0) + LATCH,
+ HSTIM_MATCH0);
+ __raw_writel(MATCH0_INT, HSTIM_INT); /* clear interrupt */
+
+ /*
+ * The goal is to keep incrementing HSTIM_MATCH0
+ * register until HSTIM_MATCH0 indicates time after
+ * what HSTIM_COUNTER indicates.
+ */
+ } while ((signed)
+ (__raw_readl(HSTIM_MATCH0) -
+ __raw_readl(HSTIM_COUNTER)) < 0);
+
+ write_sequnlock(&xtime_lock);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction pnx4008_timer_irq = {
+ .name = "PNX4008 Tick Timer",
+ .flags = SA_INTERRUPT | SA_TIMER,
+ .handler = pnx4008_timer_interrupt
+};
+
+/*!
+ * Set up timer and timer interrupt.
+ */
+static __init void pnx4008_setup_timer(void)
+{
+ __raw_writel(RESET_COUNT, MSTIM_CTRL);
+ while (__raw_readl(MSTIM_COUNTER)) ; /* wait for reset to complete. 100% guarantee event */
+ __raw_writel(0, MSTIM_CTRL); /* stop the timer */
+ __raw_writel(0, MSTIM_MCTRL);
+
+ __raw_writel(RESET_COUNT, HSTIM_CTRL);
+ while (__raw_readl(HSTIM_COUNTER)) ; /* wait for reset to complete. 100% guarantee event */
+ __raw_writel(0, HSTIM_CTRL);
+ __raw_writel(0, HSTIM_MCTRL);
+ __raw_writel(0, HSTIM_CCR);
+ __raw_writel(12, HSTIM_PMATCH); /* scale down to 1 MHZ */
+ __raw_writel(LATCH, HSTIM_MATCH0);
+ __raw_writel(MR0_INT, HSTIM_MCTRL);
+
+ setup_irq(HSTIMER_INT, &pnx4008_timer_irq);
+
+ __raw_writel(COUNT_ENAB | DEBUG_EN, HSTIM_CTRL); /*start timer, stop when JTAG active */
+}
+
+/* Timer Clock Control in PM register */
+#define TIMCLK_CTRL_REG IO_ADDRESS((PNX4008_PWRMAN_BASE + 0xBC))
+#define WATCHDOG_CLK_EN 1
+#define TIMER_CLK_EN 2 /* HS and MS timers? */
+
+static u32 timclk_ctrl_reg_save;
+
+void pnx4008_timer_suspend(void)
+{
+ timclk_ctrl_reg_save = __raw_readl(TIMCLK_CTRL_REG);
+ __raw_writel(0, TIMCLK_CTRL_REG); /* disable timers */
+}
+
+void pnx4008_timer_resume(void)
+{
+ __raw_writel(timclk_ctrl_reg_save, TIMCLK_CTRL_REG); /* enable timers */
+}
+
+struct sys_timer pnx4008_timer = {
+ .init = pnx4008_setup_timer,
+ .offset = pnx4008_gettimeoffset,
+ .suspend = pnx4008_timer_suspend,
+ .resume = pnx4008_timer_resume,
+};
+