This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / arm / mach-pnx4008 / time.c

diff --git a/arch/arm/mach-pnx4008/time.c b/arch/arm/mach-pnx4008/time.c
new file mode 100644 (file)
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+++ b/arch/arm/mach-pnx4008/time.c
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+/*
+ * 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/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 <linux/time.h>
+#include <linux/timex.h>
+#include <linux/irq.h>
+
+#include <asm/system.h>
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/leds.h>
+#include <asm/mach/time.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 = IRQF_DISABLED | IRQF_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,
+};
+