[PATCH] ARM: 2800/1: OMAP update 3/11: Move OMAP1 core code into mach-omap1 directory

Patch from Tony Lindgren

This patch by Paul Mundt and other OMAP developers
moves OMAP1 specific IRQ, time, and FPGA code into
mach-omap1 directory.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 858 insertions, 0 deletions

diff --git a/arch/arm/mach-omap1/fpga.c b/arch/arm/mach-omap1/fpga.c
new file mode 100644
index 000000000000..7c08f6c2e1d0
--- /dev/null
+++ b/arch/arm/mach-omap1/fpga.c
@@ -0,0 +1,188 @@
+/*
+ * linux/arch/arm/mach-omap/fpga.c
+ *
+ * Interrupt handler for OMAP-1510 Innovator FPGA
+ *
+ * Copyright (C) 2001 RidgeRun, Inc.
+ * Author: Greg Lonnon <glonnon@ridgerun.com>
+ *
+ * Copyright (C) 2002 MontaVista Software, Inc.
+ *
+ * Separated FPGA interrupts from innovator1510.c and cleaned up for 2.6
+ * Copyright (C) 2004 Nokia Corporation by Tony Lindrgen <tony@atomide.com>
+ *
+ * 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.
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+
+#include <asm/arch/fpga.h>
+#include <asm/arch/gpio.h>
+
+static void fpga_mask_irq(unsigned int irq)
+{
+        irq -= OMAP1510_IH_FPGA_BASE;
+
+        if (irq < 8)
+                __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO)
+                              & ~(1 << irq)), OMAP1510_FPGA_IMR_LO);
+        else if (irq < 16)
+                __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI)
+                              & ~(1 << (irq - 8))), OMAP1510_FPGA_IMR_HI);
+        else
+                __raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2)
+                              & ~(1 << (irq - 16))), INNOVATOR_FPGA_IMR2);
+}
+
+
+static inline u32 get_fpga_unmasked_irqs(void)
+{
+        return
+                ((__raw_readb(OMAP1510_FPGA_ISR_LO) &
+                  __raw_readb(OMAP1510_FPGA_IMR_LO))) |
+                ((__raw_readb(OMAP1510_FPGA_ISR_HI) &
+                  __raw_readb(OMAP1510_FPGA_IMR_HI)) << 8) |
+                ((__raw_readb(INNOVATOR_FPGA_ISR2) &
+                  __raw_readb(INNOVATOR_FPGA_IMR2)) << 16);
+}
+
+
+static void fpga_ack_irq(unsigned int irq)
+{
+        /* Don't need to explicitly ACK FPGA interrupts */
+}
+
+static void fpga_unmask_irq(unsigned int irq)
+{
+        irq -= OMAP1510_IH_FPGA_BASE;
+
+        if (irq < 8)
+                __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO) | (1 << irq)),
+                     OMAP1510_FPGA_IMR_LO);
+        else if (irq < 16)
+                __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI)
+                              | (1 << (irq - 8))), OMAP1510_FPGA_IMR_HI);
+        else
+                __raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2)
+                              | (1 << (irq - 16))), INNOVATOR_FPGA_IMR2);
+}
+
+static void fpga_mask_ack_irq(unsigned int irq)
+{
+        fpga_mask_irq(irq);
+        fpga_ack_irq(irq);
+}
+
+void innovator_fpga_IRQ_demux(unsigned int irq, struct irqdesc *desc,
+                              struct pt_regs *regs)
+{
+        struct irqdesc *d;
+        u32 stat;
+        int fpga_irq;
+
+        stat = get_fpga_unmasked_irqs();
+
+        if (!stat)
+                return;
+
+        for (fpga_irq = OMAP1510_IH_FPGA_BASE;
+             (fpga_irq < (OMAP1510_IH_FPGA_BASE + NR_FPGA_IRQS)) && stat;
+             fpga_irq++, stat >>= 1) {
+                if (stat & 1) {
+                        d = irq_desc + fpga_irq;
+                        d->handle(fpga_irq, d, regs);
+                }
+        }
+}
+
+static struct irqchip omap_fpga_irq_ack = {
+        .ack            = fpga_mask_ack_irq,
+        .mask           = fpga_mask_irq,
+        .unmask         = fpga_unmask_irq,
+};
+
+
+static struct irqchip omap_fpga_irq = {
+        .ack            = fpga_ack_irq,
+        .mask           = fpga_mask_irq,
+        .unmask         = fpga_unmask_irq,
+};
+
+/*
+ * All of the FPGA interrupt request inputs except for the touchscreen are
+ * edge-sensitive; the touchscreen is level-sensitive.  The edge-sensitive
+ * interrupts are acknowledged as a side-effect of reading the interrupt
+ * status register from the FPGA.  The edge-sensitive interrupt inputs
+ * cause a problem with level interrupt requests, such as Ethernet.  The
+ * problem occurs when a level interrupt request is asserted while its
+ * interrupt input is masked in the FPGA, which results in a missed
+ * interrupt.
+ *
+ * In an attempt to workaround the problem with missed interrupts, the
+ * mask_ack routine for all of the FPGA interrupts has been changed from
+ * fpga_mask_ack_irq() to fpga_ack_irq() so that the specific FPGA interrupt
+ * being serviced is left unmasked.  We can do this because the FPGA cascade
+ * interrupt is installed with the SA_INTERRUPT flag, which leaves all
+ * interrupts masked at the CPU while an FPGA interrupt handler executes.
+ *
+ * Limited testing indicates that this workaround appears to be effective
+ * for the smc9194 Ethernet driver used on the Innovator.  It should work
+ * on other FPGA interrupts as well, but any drivers that explicitly mask
+ * interrupts at the interrupt controller via disable_irq/enable_irq
+ * could pose a problem.
+ */
+void omap1510_fpga_init_irq(void)
+{
+        int i;
+
+        __raw_writeb(0, OMAP1510_FPGA_IMR_LO);
+        __raw_writeb(0, OMAP1510_FPGA_IMR_HI);
+        __raw_writeb(0, INNOVATOR_FPGA_IMR2);
+
+        for (i = OMAP1510_IH_FPGA_BASE; i < (OMAP1510_IH_FPGA_BASE + NR_FPGA_IRQS); i++) {
+
+                if (i == OMAP1510_INT_FPGA_TS) {
+                        /*
+                         * The touchscreen interrupt is level-sensitive, so
+                         * we'll use the regular mask_ack routine for it.
+                         */
+                        set_irq_chip(i, &omap_fpga_irq_ack);
+                }
+                else {
+                        /*
+                         * All FPGA interrupts except the touchscreen are
+                         * edge-sensitive, so we won't mask them.
+                         */
+                        set_irq_chip(i, &omap_fpga_irq);
+                }
+
+                set_irq_handler(i, do_edge_IRQ);
+                set_irq_flags(i, IRQF_VALID);
+        }
+
+        /*
+         * The FPGA interrupt line is connected to GPIO13. Claim this pin for
+         * the ARM.
+         *
+         * NOTE: For general GPIO/MPUIO access and interrupts, please see
+         * gpio.[ch]
+         */
+        omap_request_gpio(13);
+        omap_set_gpio_direction(13, 1);
+        omap_set_gpio_edge_ctrl(13, OMAP_GPIO_RISING_EDGE);
+        set_irq_chained_handler(OMAP1510_INT_FPGA, innovator_fpga_IRQ_demux);
+}
+
+EXPORT_SYMBOL(omap1510_fpga_init_irq);
diff --git a/arch/arm/mach-omap1/irq.c b/arch/arm/mach-omap1/irq.c
new file mode 100644
index 000000000000..a11b6d807352
--- /dev/null
+++ b/arch/arm/mach-omap1/irq.c
@@ -0,0 +1,234 @@
+/*
+ * linux/arch/arm/mach-omap/irq.c
+ *
+ * Interrupt handler for all OMAP boards
+ *
+ * Copyright (C) 2004 Nokia Corporation
+ * Written by Tony Lindgren <tony@atomide.com>
+ * Major cleanups by Juha Yrjölä <juha.yrjola@nokia.com>
+ *
+ * Completely re-written to support various OMAP chips with bank specific
+ * interrupt handlers.
+ *
+ * Some snippets of the code taken from the older OMAP interrupt handler
+ * Copyright (C) 2001 RidgeRun, Inc. Greg Lonnon <glonnon@ridgerun.com>
+ *
+ * GPIO interrupt handler moved to gpio.c by Juha Yrjola
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * 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.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+
+#include <asm/hardware.h>
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+#include <asm/arch/gpio.h>
+
+#include <asm/io.h>
+
+#define IRQ_BANK(irq) ((irq) >> 5)
+#define IRQ_BIT(irq)  ((irq) & 0x1f)
+
+struct omap_irq_bank {
+        unsigned long base_reg;
+        unsigned long trigger_map;
+        unsigned long wake_enable;
+};
+
+static unsigned int irq_bank_count = 0;
+static struct omap_irq_bank *irq_banks;
+
+static inline unsigned int irq_bank_readl(int bank, int offset)
+{
+        return omap_readl(irq_banks[bank].base_reg + offset);
+}
+
+static inline void irq_bank_writel(unsigned long value, int bank, int offset)
+{
+        omap_writel(value, irq_banks[bank].base_reg + offset);
+}
+
+static void omap_ack_irq(unsigned int irq)
+{
+        if (irq > 31)
+                omap_writel(0x1, OMAP_IH2_BASE + IRQ_CONTROL_REG_OFFSET);
+
+        omap_writel(0x1, OMAP_IH1_BASE + IRQ_CONTROL_REG_OFFSET);
+}
+
+static void omap_mask_irq(unsigned int irq)
+{
+        int bank = IRQ_BANK(irq);
+        u32 l;
+
+        l = omap_readl(irq_banks[bank].base_reg + IRQ_MIR_REG_OFFSET);
+        l |= 1 << IRQ_BIT(irq);
+        omap_writel(l, irq_banks[bank].base_reg + IRQ_MIR_REG_OFFSET);
+}
+
+static void omap_unmask_irq(unsigned int irq)
+{
+        int bank = IRQ_BANK(irq);
+        u32 l;
+
+        l = omap_readl(irq_banks[bank].base_reg + IRQ_MIR_REG_OFFSET);
+        l &= ~(1 << IRQ_BIT(irq));
+        omap_writel(l, irq_banks[bank].base_reg + IRQ_MIR_REG_OFFSET);
+}
+
+static void omap_mask_ack_irq(unsigned int irq)
+{
+        omap_mask_irq(irq);
+        omap_ack_irq(irq);
+}
+
+static int omap_wake_irq(unsigned int irq, unsigned int enable)
+{
+        int bank = IRQ_BANK(irq);
+
+        if (enable)
+                irq_banks[bank].wake_enable |= IRQ_BIT(irq);
+        else
+                irq_banks[bank].wake_enable &= ~IRQ_BIT(irq);
+
+        return 0;
+}
+
+
+/*
+ * Allows tuning the IRQ type and priority
+ *
+ * NOTE: There is currently no OMAP fiq handler for Linux. Read the
+ *       mailing list threads on FIQ handlers if you are planning to
+ *       add a FIQ handler for OMAP.
+ */
+static void omap_irq_set_cfg(int irq, int fiq, int priority, int trigger)
+{
+        signed int bank;
+        unsigned long val, offset;
+
+        bank = IRQ_BANK(irq);
+        /* FIQ is only available on bank 0 interrupts */
+        fiq = bank ? 0 : (fiq & 0x1);
+        val = fiq | ((priority & 0x1f) << 2) | ((trigger & 0x1) << 1);
+        offset = IRQ_ILR0_REG_OFFSET + IRQ_BIT(irq) * 0x4;
+        irq_bank_writel(val, bank, offset);
+}
+
+#ifdef CONFIG_ARCH_OMAP730
+static struct omap_irq_bank omap730_irq_banks[] = {
+        { .base_reg = OMAP_IH1_BASE,            .trigger_map = 0xb3f8e22f },
+        { .base_reg = OMAP_IH2_BASE,            .trigger_map = 0xfdb9c1f2 },
+        { .base_reg = OMAP_IH2_BASE + 0x100,    .trigger_map = 0x800040f3 },
+};
+#endif
+
+#ifdef CONFIG_ARCH_OMAP1510
+static struct omap_irq_bank omap1510_irq_banks[] = {
+        { .base_reg = OMAP_IH1_BASE,            .trigger_map = 0xb3febfff },
+        { .base_reg = OMAP_IH2_BASE,            .trigger_map = 0xffbfffed },
+};
+#endif
+
+#if defined(CONFIG_ARCH_OMAP16XX)
+
+static struct omap_irq_bank omap1610_irq_banks[] = {
+        { .base_reg = OMAP_IH1_BASE,            .trigger_map = 0xb3fefe8f },
+        { .base_reg = OMAP_IH2_BASE,            .trigger_map = 0xfdb7c1fd },
+        { .base_reg = OMAP_IH2_BASE + 0x100,    .trigger_map = 0xffffb7ff },
+        { .base_reg = OMAP_IH2_BASE + 0x200,    .trigger_map = 0xffffffff },
+};
+#endif
+
+static struct irqchip omap_irq_chip = {
+        .ack    = omap_mask_ack_irq,
+        .mask   = omap_mask_irq,
+        .unmask = omap_unmask_irq,
+        .wake   = omap_wake_irq,
+};
+
+void __init omap_init_irq(void)
+{
+        int i, j;
+
+#ifdef CONFIG_ARCH_OMAP730
+        if (cpu_is_omap730()) {
+                irq_banks = omap730_irq_banks;
+                irq_bank_count = ARRAY_SIZE(omap730_irq_banks);
+        }
+#endif
+#ifdef CONFIG_ARCH_OMAP1510
+        if (cpu_is_omap1510()) {
+                irq_banks = omap1510_irq_banks;
+                irq_bank_count = ARRAY_SIZE(omap1510_irq_banks);
+        }
+#endif
+#if defined(CONFIG_ARCH_OMAP16XX)
+        if (cpu_is_omap16xx()) {
+                irq_banks = omap1610_irq_banks;
+                irq_bank_count = ARRAY_SIZE(omap1610_irq_banks);
+        }
+#endif
+        printk("Total of %i interrupts in %i interrupt banks\n",
+               irq_bank_count * 32, irq_bank_count);
+
+        /* Mask and clear all interrupts */
+        for (i = 0; i < irq_bank_count; i++) {
+                irq_bank_writel(~0x0, i, IRQ_MIR_REG_OFFSET);
+                irq_bank_writel(0x0, i, IRQ_ITR_REG_OFFSET);
+        }
+
+        /* Clear any pending interrupts */
+        irq_bank_writel(0x03, 0, IRQ_CONTROL_REG_OFFSET);
+        irq_bank_writel(0x03, 1, IRQ_CONTROL_REG_OFFSET);
+
+        /* Enable interrupts in global mask */
+        if (cpu_is_omap730()) {
+                irq_bank_writel(0x0, 0, IRQ_GMR_REG_OFFSET);
+        }
+
+        /* Install the interrupt handlers for each bank */
+        for (i = 0; i < irq_bank_count; i++) {
+                for (j = i * 32; j < (i + 1) * 32; j++) {
+                        int irq_trigger;
+
+                        irq_trigger = irq_banks[i].trigger_map >> IRQ_BIT(j);
+                        omap_irq_set_cfg(j, 0, 0, irq_trigger);
+
+                        set_irq_chip(j, &omap_irq_chip);
+                        set_irq_handler(j, do_level_IRQ);
+                        set_irq_flags(j, IRQF_VALID);
+                }
+        }
+
+        /* Unmask level 2 handler */
+        if (cpu_is_omap730()) {
+                omap_unmask_irq(INT_730_IH2_IRQ);
+        } else {
+                omap_unmask_irq(INT_IH2_IRQ);
+        }
+}
diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
new file mode 100644
index 000000000000..d540539c9bbb
--- /dev/null
+++ b/arch/arm/mach-omap1/time.c
@@ -0,0 +1,436 @@
+/*
+ * linux/arch/arm/mach-omap1/time.c
+ *
+ * OMAP Timers
+ *
+ * Copyright (C) 2004 Nokia Corporation
+ * Partial timer rewrite and additional dynamic tick timer support by
+ * Tony Lindgen <tony@atomide.com> and
+ * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
+ *
+ * MPU timer code based on the older MPU timer code for OMAP
+ * Copyright (C) 2000 RidgeRun, Inc.
+ * Author: Greg Lonnon <glonnon@ridgerun.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * 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.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#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 <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>
+
+struct sys_timer omap_timer;
+
+#ifdef CONFIG_OMAP_MPU_TIMER
+
+/*
+ * ---------------------------------------------------------------------------
+ * MPU timer
+ * ---------------------------------------------------------------------------
+ */
+#define OMAP_MPU_TIMER_BASE             OMAP_MPU_TIMER1_BASE
+#define OMAP_MPU_TIMER_OFFSET           0x100
+
+/* cycles to nsec conversions taken from arch/i386/kernel/timers/timer_tsc.c,
+ * converted to use kHz by Kevin Hilman */
+/* convert from cycles(64bits) => nanoseconds (64bits)
+ *  basic equation:
+ *              ns = cycles / (freq / ns_per_sec)
+ *              ns = cycles * (ns_per_sec / freq)
+ *              ns = cycles * (10^9 / (cpu_khz * 10^3))
+ *              ns = cycles * (10^6 / cpu_khz)
+ *
+ *      Then we use scaling math (suggested by george at mvista.com) to get:
+ *              ns = cycles * (10^6 * SC / cpu_khz / SC
+ *              ns = cycles * cyc2ns_scale / SC
+ *
+ *      And since SC is a constant power of two, we can convert the div
+ *  into a shift.
+ *                      -johnstul at us.ibm.com "math is hard, lets go shopping!"
+ */
+static unsigned long cyc2ns_scale;
+#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
+
+static inline void set_cyc2ns_scale(unsigned long cpu_khz)
+{
+        cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR)/cpu_khz;
+}
+
+static inline unsigned long long cycles_2_ns(unsigned long long cyc)
+{
+        return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
+}
+
+/*
+ * MPU_TICKS_PER_SEC must be an even number, otherwise machinecycles_to_usecs
+ * will break. On P2, the timer count rate is 6.5 MHz after programming PTV
+ * with 0. This divides the 13MHz input by 2, and is undocumented.
+ */
+#ifdef CONFIG_MACH_OMAP_PERSEUS2
+/* REVISIT: This ifdef construct should be replaced by a query to clock
+ * framework to see if timer base frequency is 12.0, 13.0 or 19.2 MHz.
+ */
+#define MPU_TICKS_PER_SEC               (13000000 / 2)
+#else
+#define MPU_TICKS_PER_SEC               (12000000 / 2)
+#endif
+
+#define MPU_TIMER_TICK_PERIOD           ((MPU_TICKS_PER_SEC / HZ) - 1)
+
+typedef struct {
+        u32 cntl;                       /* CNTL_TIMER, R/W */
+        u32 load_tim;                   /* LOAD_TIM,   W */
+        u32 read_tim;                   /* READ_TIM,   R */
+} omap_mpu_timer_regs_t;
+
+#define omap_mpu_timer_base(n)                                          \
+((volatile omap_mpu_timer_regs_t*)IO_ADDRESS(OMAP_MPU_TIMER_BASE +      \
+                                 (n)*OMAP_MPU_TIMER_OFFSET))
+
+static inline unsigned long omap_mpu_timer_read(int nr)
+{
+        volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+        return timer->read_tim;
+}
+
+static inline void omap_mpu_timer_start(int nr, unsigned long load_val)
+{
+        volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+
+        timer->cntl = MPU_TIMER_CLOCK_ENABLE;
+        udelay(1);
+        timer->load_tim = load_val;
+        udelay(1);
+        timer->cntl = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_AR | MPU_TIMER_ST);
+}
+
+unsigned long omap_mpu_timer_ticks_to_usecs(unsigned long nr_ticks)
+{
+        unsigned long long nsec;
+
+        nsec = cycles_2_ns((unsigned long long)nr_ticks);
+        return (unsigned long)nsec / 1000;
+}
+
+/*
+ * Last processed system timer interrupt
+ */
+static unsigned long omap_mpu_timer_last = 0;
+
+/*
+ * Returns elapsed usecs since last system timer interrupt
+ */
+static unsigned long omap_mpu_timer_gettimeoffset(void)
+{
+        unsigned long now = 0 - omap_mpu_timer_read(0);
+        unsigned long elapsed = now - omap_mpu_timer_last;
+
+        return omap_mpu_timer_ticks_to_usecs(elapsed);
+}
+
+/*
+ * Elapsed time between interrupts is calculated using timer0.
+ * Latency during the interrupt is calculated using timer1.
+ * Both timer0 and timer1 are counting at 6MHz (P2 6.5MHz).
+ */
+static irqreturn_t omap_mpu_timer_interrupt(int irq, void *dev_id,
+                                        struct pt_regs *regs)
+{
+        unsigned long now, latency;
+
+        write_seqlock(&xtime_lock);
+        now = 0 - omap_mpu_timer_read(0);
+        latency = MPU_TICKS_PER_SEC / HZ - omap_mpu_timer_read(1);
+        omap_mpu_timer_last = now - latency;
+        timer_tick(regs);
+        write_sequnlock(&xtime_lock);
+
+        return IRQ_HANDLED;
+}
+
+static struct irqaction omap_mpu_timer_irq = {
+        .name           = "mpu timer",
+        .flags          = SA_INTERRUPT | SA_TIMER,
+        .handler        = omap_mpu_timer_interrupt,
+};
+
+static unsigned long omap_mpu_timer1_overflows;
+static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id,
+                                             struct pt_regs *regs)
+{
+        omap_mpu_timer1_overflows++;
+        return IRQ_HANDLED;
+}
+
+static struct irqaction omap_mpu_timer1_irq = {
+        .name           = "mpu timer1 overflow",
+        .flags          = SA_INTERRUPT,
+        .handler        = omap_mpu_timer1_interrupt,
+};
+
+static __init void omap_init_mpu_timer(void)
+{
+        set_cyc2ns_scale(MPU_TICKS_PER_SEC / 1000);
+        omap_timer.offset = omap_mpu_timer_gettimeoffset;
+        setup_irq(INT_TIMER1, &omap_mpu_timer1_irq);
+        setup_irq(INT_TIMER2, &omap_mpu_timer_irq);
+        omap_mpu_timer_start(0, 0xffffffff);
+        omap_mpu_timer_start(1, MPU_TIMER_TICK_PERIOD);
+}
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+        unsigned long ticks = 0 - omap_mpu_timer_read(0);
+        unsigned long long ticks64;
+
+        ticks64 = omap_mpu_timer1_overflows;
+        ticks64 <<= 32;
+        ticks64 |= ticks;
+
+        return cycles_2_ns(ticks64);
+}
+#endif  /* CONFIG_OMAP_MPU_TIMER */
+
+#ifdef CONFIG_OMAP_32K_TIMER
+
+#ifdef CONFIG_ARCH_OMAP1510
+#error OMAP 32KHz timer does not currently work on 1510!
+#endif
+
+/*
+ * ---------------------------------------------------------------------------
+ * 32KHz OS timer
+ *
+ * This currently works only on 16xx, as 1510 does not have the continuous
+ * 32KHz synchronous timer. The 32KHz synchronous timer is used to keep track
+ * of time in addition to the 32KHz OS timer. Using only the 32KHz OS timer
+ * on 1510 would be possible, but the timer would not be as accurate as
+ * with the 32KHz synchronized timer.
+ * ---------------------------------------------------------------------------
+ */
+#define OMAP_32K_TIMER_BASE             0xfffb9000
+#define OMAP_32K_TIMER_CR               0x08
+#define OMAP_32K_TIMER_TVR              0x00
+#define OMAP_32K_TIMER_TCR              0x04
+
+#define OMAP_32K_TICKS_PER_HZ           (32768 / HZ)
+#if (32768 % HZ) != 0
+/* We cannot ignore modulo.
+ * Potential error can be as high as several percent.
+ */
+#define OMAP_32K_TICK_MODULO            (32768 % HZ)
+static unsigned modulo_count = 0; /* Counts 1/HZ units */
+#endif
+
+/*
+ * TRM says 1 / HZ = ( TVR + 1) / 32768, so TRV = (32768 / HZ) - 1
+ * so with HZ = 100, TVR = 327.68.
+ */
+#define OMAP_32K_TIMER_TICK_PERIOD      ((32768 / HZ) - 1)
+#define TIMER_32K_SYNCHRONIZED          0xfffbc410
+
+#define JIFFIES_TO_HW_TICKS(nr_jiffies, clock_rate)                     \
+                                (((nr_jiffies) * (clock_rate)) / HZ)
+
+static inline void omap_32k_timer_write(int val, int reg)
+{
+        omap_writew(val, reg + OMAP_32K_TIMER_BASE);
+}
+
+static inline unsigned long omap_32k_timer_read(int reg)
+{
+        return omap_readl(reg + OMAP_32K_TIMER_BASE) & 0xffffff;
+}
+
+/*
+ * The 32KHz synchronized timer is an additional timer on 16xx.
+ * It is always running.
+ */
+static inline unsigned long omap_32k_sync_timer_read(void)
+{
+        return omap_readl(TIMER_32K_SYNCHRONIZED);
+}
+
+static inline void omap_32k_timer_start(unsigned long load_val)
+{
+        omap_32k_timer_write(load_val, OMAP_32K_TIMER_TVR);
+        omap_32k_timer_write(0x0f, OMAP_32K_TIMER_CR);
+}
+
+static inline void omap_32k_timer_stop(void)
+{
+        omap_32k_timer_write(0x0, OMAP_32K_TIMER_CR);
+}
+
+/*
+ * Rounds down to nearest usec
+ */
+static inline unsigned long omap_32k_ticks_to_usecs(unsigned long ticks_32k)
+{
+        return (ticks_32k * 5*5*5*5*5*5) >> 9;
+}
+
+static unsigned long omap_32k_last_tick = 0;
+
+/*
+ * Returns elapsed usecs since last 32k timer interrupt
+ */
+static unsigned long omap_32k_timer_gettimeoffset(void)
+{
+        unsigned long now = omap_32k_sync_timer_read();
+        return omap_32k_ticks_to_usecs(now - omap_32k_last_tick);
+}
+
+/*
+ * Timer interrupt for 32KHz timer. When dynamic tick is enabled, this
+ * function is also called from other interrupts to remove latency
+ * issues with dynamic tick. In the dynamic tick case, we need to lock
+ * with irqsave.
+ */
+static irqreturn_t omap_32k_timer_interrupt(int irq, void *dev_id,
+                                            struct pt_regs *regs)
+{
+        unsigned long flags;
+        unsigned long now;
+
+        write_seqlock_irqsave(&xtime_lock, flags);
+        now = omap_32k_sync_timer_read();
+
+        while (now - omap_32k_last_tick >= OMAP_32K_TICKS_PER_HZ) {
+#ifdef OMAP_32K_TICK_MODULO
+                /* Modulo addition may put omap_32k_last_tick ahead of now
+                 * and cause unwanted repetition of the while loop.
+                 */
+                if (unlikely(now - omap_32k_last_tick == ~0))
+                        break;
+
+                modulo_count += OMAP_32K_TICK_MODULO;
+                if (modulo_count > HZ) {
+                        ++omap_32k_last_tick;
+                        modulo_count -= HZ;
+                }
+#endif
+                omap_32k_last_tick += OMAP_32K_TICKS_PER_HZ;
+                timer_tick(regs);
+        }
+
+        /* Restart timer so we don't drift off due to modulo or dynamic tick.
+         * By default we program the next timer to be continuous to avoid
+         * latencies during high system load. During dynamic tick operation the
+         * continuous timer can be overridden from pm_idle to be longer.
+         */
+        omap_32k_timer_start(omap_32k_last_tick + OMAP_32K_TICKS_PER_HZ - now);
+        write_sequnlock_irqrestore(&xtime_lock, flags);
+
+        return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_NO_IDLE_HZ
+/*
+ * Programs the next timer interrupt needed. Called when dynamic tick is
+ * enabled, and to reprogram the ticks to skip from pm_idle. Note that
+ * we can keep the timer continuous, and don't need to set it to run in
+ * one-shot mode. This is because the timer will get reprogrammed again
+ * after next interrupt.
+ */
+void omap_32k_timer_reprogram(unsigned long next_tick)
+{
+        omap_32k_timer_start(JIFFIES_TO_HW_TICKS(next_tick, 32768) + 1);
+}
+
+static struct irqaction omap_32k_timer_irq;
+extern struct timer_update_handler timer_update;
+
+static int omap_32k_timer_enable_dyn_tick(void)
+{
+        /* No need to reprogram timer, just use the next interrupt */
+        return 0;
+}
+
+static int omap_32k_timer_disable_dyn_tick(void)
+{
+        omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
+        return 0;
+}
+
+static struct dyn_tick_timer omap_dyn_tick_timer = {
+        .enable         = omap_32k_timer_enable_dyn_tick,
+        .disable        = omap_32k_timer_disable_dyn_tick,
+        .reprogram      = omap_32k_timer_reprogram,
+        .handler        = omap_32k_timer_interrupt,
+};
+#endif  /* CONFIG_NO_IDLE_HZ */
+
+static struct irqaction omap_32k_timer_irq = {
+        .name           = "32KHz timer",
+        .flags          = SA_INTERRUPT | SA_TIMER,
+        .handler        = omap_32k_timer_interrupt,
+};
+
+static __init void omap_init_32k_timer(void)
+{
+
+#ifdef CONFIG_NO_IDLE_HZ
+        omap_timer.dyn_tick = &omap_dyn_tick_timer;
+#endif
+
+        setup_irq(INT_OS_TIMER, &omap_32k_timer_irq);
+        omap_timer.offset  = omap_32k_timer_gettimeoffset;
+        omap_32k_last_tick = omap_32k_sync_timer_read();
+        omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
+}
+#endif  /* CONFIG_OMAP_32K_TIMER */
+
+/*
+ * ---------------------------------------------------------------------------
+ * Timer initialization
+ * ---------------------------------------------------------------------------
+ */
+static void __init omap_timer_init(void)
+{
+#if defined(CONFIG_OMAP_MPU_TIMER)
+        omap_init_mpu_timer();
+#elif defined(CONFIG_OMAP_32K_TIMER)
+        omap_init_32k_timer();
+#else
+#error No system timer selected in Kconfig!
+#endif
+}
+
+struct sys_timer omap_timer = {
+        .init           = omap_timer_init,
+        .offset         = NULL,         /* Initialized later */
+};