Merge tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC cleanups from Arnd Bergmann:
 "A large number of cleanups, all over the platforms.  This is dominated
  largely by the Samsung platforms (s3c, s5p, exynos) and a few of the
  others moving code out of arch/arm into more appropriate subsystems.

  The clocksource and irqchip drivers are now abstracted to the point
  where platforms that are already cleaned up do not need to even
  specify the driver they use, it can all get configured from the device
  tree as we do for normal device drivers.  The clocksource changes
  basically touch every single platform in the process.

  We further clean up the use of platform specific header files here,
  with the goal of turning more of the platforms over to being
  "multiplatform" enabled, which implies that they cannot expose their
  headers to architecture independent code any more.

  It is expected that no functional changes are part of the cleanup.
  The overall reduction in total code lines is mostly the result of
  removing broken and obsolete code."

* tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (133 commits)
  ARM: mvebu: correct gated clock documentation
  ARM: kirkwood: add missing include for nsa310
  ARM: exynos: move exynos4210-combiner to drivers/irqchip
  mfd: db8500-prcmu: update resource passing
  drivers/db8500-cpufreq: delete dangling include
  ARM: at91: remove NEOCORE 926 board
  sunxi: Cleanup the reset code and add meaningful registers defines
  ARM: S3C24XX: header mach/regs-mem.h local
  ARM: S3C24XX: header mach/regs-power.h local
  ARM: S3C24XX: header mach/regs-s3c2412-mem.h local
  ARM: S3C24XX: Remove plat-s3c24xx directory in arch/arm/
  ARM: S3C24XX: transform s3c2443 subirqs into new structure
  ARM: S3C24XX: modify s3c2443 irq init to initialize all irqs
  ARM: S3C24XX: move s3c2443 irq code to irq.c
  ARM: S3C24XX: transform s3c2416 irqs into new structure
  ARM: S3C24XX: modify s3c2416 irq init to initialize all irqs
  ARM: S3C24XX: move s3c2416 irq init to common irq code
  ARM: S3C24XX: Modify s3c_irq_wake to use the hwirq property
  ARM: S3C24XX: Move irq syscore-ops to irq-pm
  clocksource: always define CLOCKSOURCE_OF_DECLARE
  ...

11 files changed, 535 insertions, 53 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 7fdcbd3f4da5..7d978c1bd528 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -1,3 +1,6 @@
+config CLKSRC_OF
+        bool
+
 config CLKSRC_I8253
         bool
 
@@ -25,6 +28,9 @@ config ARMADA_370_XP_TIMER
 config SUNXI_TIMER
         bool
 
+config VT8500_TIMER
+        bool
+
 config CLKSRC_NOMADIK_MTU
         bool
         depends on (ARCH_NOMADIK || ARCH_U8500)
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index f93453d01673..596c45c2f192 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_CLKSRC_OF) += clksrc-of.o
 obj-$(CONFIG_ATMEL_TCB_CLKSRC)  += tcb_clksrc.o
 obj-$(CONFIG_X86_CYCLONE_TIMER) += cyclone.o
 obj-$(CONFIG_X86_PM_TIMER)      += acpi_pm.o
@@ -16,5 +17,7 @@ obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
 obj-$(CONFIG_ARMADA_370_XP_TIMER)       += time-armada-370-xp.o
 obj-$(CONFIG_ARCH_BCM2835)      += bcm2835_timer.o
 obj-$(CONFIG_SUNXI_TIMER)       += sunxi_timer.o
+obj-$(CONFIG_ARCH_TEGRA)        += tegra20_timer.o
+obj-$(CONFIG_VT8500_TIMER)      += vt8500_timer.o
 
 obj-$(CONFIG_CLKSRC_ARM_GENERIC)        += arm_generic.o
diff --git a/drivers/clocksource/bcm2835_timer.c b/drivers/clocksource/bcm2835_timer.c
index bc19f12c20ce..50c68fef944b 100644
--- a/drivers/clocksource/bcm2835_timer.c
+++ b/drivers/clocksource/bcm2835_timer.c
@@ -16,7 +16,6 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-#include <linux/bcm2835_timer.h>
 #include <linux/bitops.h>
 #include <linux/clockchips.h>
 #include <linux/clocksource.h>
@@ -101,7 +100,7 @@ static struct of_device_id bcm2835_time_match[] __initconst = {
         {}
 };
 
-static void __init bcm2835_time_init(void)
+static void __init bcm2835_timer_init(void)
 {
         struct device_node *node;
         void __iomem *base;
@@ -155,7 +154,5 @@ static void __init bcm2835_time_init(void)
 
         pr_info("bcm2835: system timer (irq = %d)\n", irq);
 }
-
-struct sys_timer bcm2835_timer = {
-        .init = bcm2835_time_init,
-};
+CLOCKSOURCE_OF_DECLARE(bcm2835, "brcm,bcm2835-system-timer",
+                        bcm2835_timer_init);
diff --git a/drivers/clocksource/clksrc-of.c b/drivers/clocksource/clksrc-of.c
new file mode 100644
index 000000000000..bdabdaa8d00f
--- /dev/null
+++ b/drivers/clocksource/clksrc-of.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+#include <linux/of.h>
+
+extern struct of_device_id __clksrc_of_table[];
+
+static const struct of_device_id __clksrc_of_table_sentinel
+        __used __section(__clksrc_of_table_end);
+
+void __init clocksource_of_init(void)
+{
+        struct device_node *np;
+        const struct of_device_id *match;
+        void (*init_func)(void);
+
+        for_each_matching_node_and_match(np, __clksrc_of_table, &match) {
+                init_func = match->data;
+                init_func();
+        }
+}
diff --git a/drivers/clocksource/cs5535-clockevt.c b/drivers/clocksource/cs5535-clockevt.c
index d9279385304d..ea210482dd20 100644
--- a/drivers/clocksource/cs5535-clockevt.c
+++ b/drivers/clocksource/cs5535-clockevt.c
@@ -100,7 +100,6 @@ static struct clock_event_device cs5535_clockevent = {
         .set_mode = mfgpt_set_mode,
         .set_next_event = mfgpt_next_event,
         .rating = 250,
-        .shift = 32
 };
 
 static irqreturn_t mfgpt_tick(int irq, void *dev_id)
@@ -169,17 +168,11 @@ static int __init cs5535_mfgpt_init(void)
         cs5535_mfgpt_write(cs5535_event_clock, MFGPT_REG_SETUP, val);
 
         /* Set up the clock event */
-        cs5535_clockevent.mult = div_sc(MFGPT_HZ, NSEC_PER_SEC,
-                        cs5535_clockevent.shift);
-        cs5535_clockevent.min_delta_ns = clockevent_delta2ns(0xF,
-                        &cs5535_clockevent);
-        cs5535_clockevent.max_delta_ns = clockevent_delta2ns(0xFFFE,
-                        &cs5535_clockevent);
-
         printk(KERN_INFO DRV_NAME
                 ": Registering MFGPT timer as a clock event, using IRQ %d\n",
                 timer_irq);
-        clockevents_register_device(&cs5535_clockevent);
+        clockevents_config_and_register(&cs5535_clockevent, MFGPT_HZ,
+                                        0xF, 0xFFFE);
 
         return 0;
 
diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index f7dba5b79b44..ab09ed3742ee 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -107,7 +107,7 @@ static const struct of_device_id osctimer_ids[] __initconst = {
         {},
 };
 
-static void __init timer_init(void)
+void __init dw_apb_timer_init(void)
 {
         struct device_node *event_timer, *source_timer;
 
@@ -125,7 +125,3 @@ static void __init timer_init(void)
 
         init_sched_clock();
 }
-
-struct sys_timer dw_apb_timer = {
-        .init = timer_init,
-};
diff --git a/drivers/clocksource/nomadik-mtu.c b/drivers/clocksource/nomadik-mtu.c
index 8914c3c1c88b..025afc6dd324 100644
--- a/drivers/clocksource/nomadik-mtu.c
+++ b/drivers/clocksource/nomadik-mtu.c
@@ -134,12 +134,32 @@ static void nmdk_clkevt_mode(enum clock_event_mode mode,
         }
 }
 
+void nmdk_clksrc_reset(void)
+{
+        /* Disable */
+        writel(0, mtu_base + MTU_CR(0));
+
+        /* ClockSource: configure load and background-load, and fire it up */
+        writel(nmdk_cycle, mtu_base + MTU_LR(0));
+        writel(nmdk_cycle, mtu_base + MTU_BGLR(0));
+
+        writel(clk_prescale | MTU_CRn_32BITS | MTU_CRn_ENA,
+               mtu_base + MTU_CR(0));
+}
+
+static void nmdk_clkevt_resume(struct clock_event_device *cedev)
+{
+        nmdk_clkevt_reset();
+        nmdk_clksrc_reset();
+}
+
 static struct clock_event_device nmdk_clkevt = {
         .name           = "mtu_1",
         .features       = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
         .rating         = 200,
         .set_mode       = nmdk_clkevt_mode,
         .set_next_event = nmdk_clkevt_next,
+        .resume         = nmdk_clkevt_resume,
 };
 
 /*
@@ -161,19 +181,6 @@ static struct irqaction nmdk_timer_irq = {
         .dev_id         = &nmdk_clkevt,
 };
 
-void nmdk_clksrc_reset(void)
-{
-        /* Disable */
-        writel(0, mtu_base + MTU_CR(0));
-
-        /* ClockSource: configure load and background-load, and fire it up */
-        writel(nmdk_cycle, mtu_base + MTU_LR(0));
-        writel(nmdk_cycle, mtu_base + MTU_BGLR(0));
-
-        writel(clk_prescale | MTU_CRn_32BITS | MTU_CRn_ENA,
-               mtu_base + MTU_CR(0));
-}
-
 void __init nmdk_timer_init(void __iomem *base, int irq)
 {
         unsigned long rate;
diff --git a/drivers/clocksource/sunxi_timer.c b/drivers/clocksource/sunxi_timer.c
index 93d09d0e009f..4086b9167159 100644
--- a/drivers/clocksource/sunxi_timer.c
+++ b/drivers/clocksource/sunxi_timer.c
@@ -74,7 +74,6 @@ static int sunxi_clkevt_next_event(unsigned long evt,
 
 static struct clock_event_device sunxi_clockevent = {
         .name = "sunxi_tick",
-        .shift = 32,
         .rating = 300,
         .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
         .set_mode = sunxi_clkevt_mode,
@@ -104,7 +103,7 @@ static struct of_device_id sunxi_timer_dt_ids[] = {
         { }
 };
 
-static void __init sunxi_timer_init(void)
+void __init sunxi_timer_init(void)
 {
         struct device_node *node;
         unsigned long rate = 0;
@@ -154,18 +153,8 @@ static void __init sunxi_timer_init(void)
         val = readl(timer_base + TIMER_CTL_REG);
         writel(val | TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG);
 
-        sunxi_clockevent.mult = div_sc(rate / TIMER_SCAL,
-                                NSEC_PER_SEC,
-                                sunxi_clockevent.shift);
-        sunxi_clockevent.max_delta_ns = clockevent_delta2ns(0xff,
-                                                            &sunxi_clockevent);
-        sunxi_clockevent.min_delta_ns = clockevent_delta2ns(0x1,
-                                                            &sunxi_clockevent);
         sunxi_clockevent.cpumask = cpumask_of(0);
 
-        clockevents_register_device(&sunxi_clockevent);
+        clockevents_config_and_register(&sunxi_clockevent, rate / TIMER_SCAL,
+                                        0x1, 0xff);
 }
-
-struct sys_timer sunxi_timer = {
-        .init = sunxi_timer_init,
-};
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 32cb929b8eb6..8a6187225dd0 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -157,7 +157,6 @@ static struct tc_clkevt_device clkevt = {
                 .name           = "tc_clkevt",
                 .features       = CLOCK_EVT_FEAT_PERIODIC
                                         | CLOCK_EVT_FEAT_ONESHOT,
-                .shift          = 32,
                 /* Should be lower than at91rm9200's system timer */
                 .rating         = 125,
                 .set_next_event = tc_next_event,
@@ -196,13 +195,9 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 
         timer_clock = clk32k_divisor_idx;
 
-        clkevt.clkevt.mult = div_sc(32768, NSEC_PER_SEC, clkevt.clkevt.shift);
-        clkevt.clkevt.max_delta_ns
-                = clockevent_delta2ns(0xffff, &clkevt.clkevt);
-        clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
         clkevt.clkevt.cpumask = cpumask_of(0);
 
-        clockevents_register_device(&clkevt.clkevt);
+        clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
 
         setup_irq(irq, &tc_irqaction);
 }
diff --git a/drivers/clocksource/tegra20_timer.c b/drivers/clocksource/tegra20_timer.c
new file mode 100644
index 000000000000..0bde03feb095
--- /dev/null
+++ b/drivers/clocksource/tegra20_timer.c
@@ -0,0 +1,281 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ *      Colin Cross <ccross@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <asm/mach/time.h>
+#include <asm/smp_twd.h>
+#include <asm/sched_clock.h>
+
+#define RTC_SECONDS            0x08
+#define RTC_SHADOW_SECONDS     0x0c
+#define RTC_MILLISECONDS       0x10
+
+#define TIMERUS_CNTR_1US 0x10
+#define TIMERUS_USEC_CFG 0x14
+#define TIMERUS_CNTR_FREEZE 0x4c
+
+#define TIMER1_BASE 0x0
+#define TIMER2_BASE 0x8
+#define TIMER3_BASE 0x50
+#define TIMER4_BASE 0x58
+
+#define TIMER_PTV 0x0
+#define TIMER_PCR 0x4
+
+static void __iomem *timer_reg_base;
+static void __iomem *rtc_base;
+
+static struct timespec persistent_ts;
+static u64 persistent_ms, last_persistent_ms;
+
+#define timer_writel(value, reg) \
+        __raw_writel(value, timer_reg_base + (reg))
+#define timer_readl(reg) \
+        __raw_readl(timer_reg_base + (reg))
+
+static int tegra_timer_set_next_event(unsigned long cycles,
+                                         struct clock_event_device *evt)
+{
+        u32 reg;
+
+        reg = 0x80000000 | ((cycles > 1) ? (cycles-1) : 0);
+        timer_writel(reg, TIMER3_BASE + TIMER_PTV);
+
+        return 0;
+}
+
+static void tegra_timer_set_mode(enum clock_event_mode mode,
+                                    struct clock_event_device *evt)
+{
+        u32 reg;
+
+        timer_writel(0, TIMER3_BASE + TIMER_PTV);
+
+        switch (mode) {
+        case CLOCK_EVT_MODE_PERIODIC:
+                reg = 0xC0000000 | ((1000000/HZ)-1);
+                timer_writel(reg, TIMER3_BASE + TIMER_PTV);
+                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 tegra_clockevent = {
+        .name           = "timer0",
+        .rating         = 300,
+        .features       = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+        .set_next_event = tegra_timer_set_next_event,
+        .set_mode       = tegra_timer_set_mode,
+};
+
+static u32 notrace tegra_read_sched_clock(void)
+{
+        return timer_readl(TIMERUS_CNTR_1US);
+}
+
+/*
+ * tegra_rtc_read - Reads the Tegra RTC registers
+ * Care must be taken that this funciton is not called while the
+ * tegra_rtc driver could be executing to avoid race conditions
+ * on the RTC shadow register
+ */
+static u64 tegra_rtc_read_ms(void)
+{
+        u32 ms = readl(rtc_base + RTC_MILLISECONDS);
+        u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
+        return (u64)s * MSEC_PER_SEC + ms;
+}
+
+/*
+ * tegra_read_persistent_clock -  Return time from a persistent clock.
+ *
+ * Reads the time from a source which isn't disabled during PM, the
+ * 32k sync timer.  Convert the cycles elapsed since last read into
+ * nsecs and adds to a monotonically increasing timespec.
+ * Care must be taken that this funciton is not called while the
+ * tegra_rtc driver could be executing to avoid race conditions
+ * on the RTC shadow register
+ */
+static void tegra_read_persistent_clock(struct timespec *ts)
+{
+        u64 delta;
+        struct timespec *tsp = &persistent_ts;
+
+        last_persistent_ms = persistent_ms;
+        persistent_ms = tegra_rtc_read_ms();
+        delta = persistent_ms - last_persistent_ms;
+
+        timespec_add_ns(tsp, delta * NSEC_PER_MSEC);
+        *ts = *tsp;
+}
+
+static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id)
+{
+        struct clock_event_device *evt = (struct clock_event_device *)dev_id;
+        timer_writel(1<<30, TIMER3_BASE + TIMER_PCR);
+        evt->event_handler(evt);
+        return IRQ_HANDLED;
+}
+
+static struct irqaction tegra_timer_irq = {
+        .name           = "timer0",
+        .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_HIGH,
+        .handler        = tegra_timer_interrupt,
+        .dev_id         = &tegra_clockevent,
+};
+
+static const struct of_device_id timer_match[] __initconst = {
+        { .compatible = "nvidia,tegra20-timer" },
+        {}
+};
+
+static const struct of_device_id rtc_match[] __initconst = {
+        { .compatible = "nvidia,tegra20-rtc" },
+        {}
+};
+
+static void __init tegra20_init_timer(void)
+{
+        struct device_node *np;
+        struct clk *clk;
+        unsigned long rate;
+        int ret;
+
+        np = of_find_matching_node(NULL, timer_match);
+        if (!np) {
+                pr_err("Failed to find timer DT node\n");
+                BUG();
+        }
+
+        timer_reg_base = of_iomap(np, 0);
+        if (!timer_reg_base) {
+                pr_err("Can't map timer registers\n");
+                BUG();
+        }
+
+        tegra_timer_irq.irq = irq_of_parse_and_map(np, 2);
+        if (tegra_timer_irq.irq <= 0) {
+                pr_err("Failed to map timer IRQ\n");
+                BUG();
+        }
+
+        clk = clk_get_sys("timer", NULL);
+        if (IS_ERR(clk)) {
+                pr_warn("Unable to get timer clock. Assuming 12Mhz input clock.\n");
+                rate = 12000000;
+        } else {
+                clk_prepare_enable(clk);
+                rate = clk_get_rate(clk);
+        }
+
+        of_node_put(np);
+
+        np = of_find_matching_node(NULL, rtc_match);
+        if (!np) {
+                pr_err("Failed to find RTC DT node\n");
+                BUG();
+        }
+
+        rtc_base = of_iomap(np, 0);
+        if (!rtc_base) {
+                pr_err("Can't map RTC registers");
+                BUG();
+        }
+
+        /*
+         * rtc registers are used by read_persistent_clock, keep the rtc clock
+         * enabled
+         */
+        clk = clk_get_sys("rtc-tegra", NULL);
+        if (IS_ERR(clk))
+                pr_warn("Unable to get rtc-tegra clock\n");
+        else
+                clk_prepare_enable(clk);
+
+        of_node_put(np);
+
+        switch (rate) {
+        case 12000000:
+                timer_writel(0x000b, TIMERUS_USEC_CFG);
+                break;
+        case 13000000:
+                timer_writel(0x000c, TIMERUS_USEC_CFG);
+                break;
+        case 19200000:
+                timer_writel(0x045f, TIMERUS_USEC_CFG);
+                break;
+        case 26000000:
+                timer_writel(0x0019, TIMERUS_USEC_CFG);
+                break;
+        default:
+                WARN(1, "Unknown clock rate");
+        }
+
+        setup_sched_clock(tegra_read_sched_clock, 32, 1000000);
+
+        if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
+                "timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) {
+                pr_err("Failed to register clocksource\n");
+                BUG();
+        }
+
+        ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);
+        if (ret) {
+                pr_err("Failed to register timer IRQ: %d\n", ret);
+                BUG();
+        }
+
+        tegra_clockevent.cpumask = cpu_all_mask;
+        tegra_clockevent.irq = tegra_timer_irq.irq;
+        clockevents_config_and_register(&tegra_clockevent, 1000000,
+                                        0x1, 0x1fffffff);
+#ifdef CONFIG_HAVE_ARM_TWD
+        twd_local_timer_of_register();
+#endif
+        register_persistent_clock(NULL, tegra_read_persistent_clock);
+}
+CLOCKSOURCE_OF_DECLARE(tegra20, "nvidia,tegra20-timer", tegra20_init_timer);
+
+#ifdef CONFIG_PM
+static u32 usec_config;
+
+void tegra_timer_suspend(void)
+{
+        usec_config = timer_readl(TIMERUS_USEC_CFG);
+}
+
+void tegra_timer_resume(void)
+{
+        timer_writel(usec_config, TIMERUS_USEC_CFG);
+}
+#endif
diff --git a/drivers/clocksource/vt8500_timer.c b/drivers/clocksource/vt8500_timer.c
new file mode 100644
index 000000000000..8efc86b5b5dd
--- /dev/null
+++ b/drivers/clocksource/vt8500_timer.c
@@ -0,0 +1,180 @@
+/*
+ *  arch/arm/mach-vt8500/timer.c
+ *
+ *  Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
+ *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.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 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
+ */
+
+/*
+ * This file is copied and modified from the original timer.c provided by
+ * Alexey Charkov. Minor changes have been made for Device Tree Support.
+ */
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/delay.h>
+#include <asm/mach/time.h>
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#define VT8500_TIMER_OFFSET     0x0100
+#define VT8500_TIMER_HZ         3000000
+#define TIMER_MATCH_VAL         0x0000
+#define TIMER_COUNT_VAL         0x0010
+#define TIMER_STATUS_VAL        0x0014
+#define TIMER_IER_VAL           0x001c          /* interrupt enable */
+#define TIMER_CTRL_VAL          0x0020
+#define TIMER_AS_VAL            0x0024          /* access status */
+#define TIMER_COUNT_R_ACTIVE    (1 << 5)        /* not ready for read */
+#define TIMER_COUNT_W_ACTIVE    (1 << 4)        /* not ready for write */
+#define TIMER_MATCH_W_ACTIVE    (1 << 0)        /* not ready for write */
+
+#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
+
+static void __iomem *regbase;
+
+static cycle_t vt8500_timer_read(struct clocksource *cs)
+{
+        int loops = msecs_to_loops(10);
+        writel(3, regbase + TIMER_CTRL_VAL);
+        while ((readl((regbase + TIMER_AS_VAL)) & TIMER_COUNT_R_ACTIVE)
+                                                && --loops)
+                cpu_relax();
+        return readl(regbase + TIMER_COUNT_VAL);
+}
+
+static struct clocksource clocksource = {
+        .name           = "vt8500_timer",
+        .rating         = 200,
+        .read           = vt8500_timer_read,
+        .mask           = CLOCKSOURCE_MASK(32),
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int vt8500_timer_set_next_event(unsigned long cycles,
+                                    struct clock_event_device *evt)
+{
+        int loops = msecs_to_loops(10);
+        cycle_t alarm = clocksource.read(&clocksource) + cycles;
+        while ((readl(regbase + TIMER_AS_VAL) & TIMER_MATCH_W_ACTIVE)
+                                                && --loops)
+                cpu_relax();
+        writel((unsigned long)alarm, regbase + TIMER_MATCH_VAL);
+
+        if ((signed)(alarm - clocksource.read(&clocksource)) <= 16)
+                return -ETIME;
+
+        writel(1, regbase + TIMER_IER_VAL);
+
+        return 0;
+}
+
+static void vt8500_timer_set_mode(enum clock_event_mode mode,
+                              struct clock_event_device *evt)
+{
+        switch (mode) {
+        case CLOCK_EVT_MODE_RESUME:
+        case CLOCK_EVT_MODE_PERIODIC:
+                break;
+        case CLOCK_EVT_MODE_ONESHOT:
+        case CLOCK_EVT_MODE_UNUSED:
+        case CLOCK_EVT_MODE_SHUTDOWN:
+                writel(readl(regbase + TIMER_CTRL_VAL) | 1,
+                        regbase + TIMER_CTRL_VAL);
+                writel(0, regbase + TIMER_IER_VAL);
+                break;
+        }
+}
+
+static struct clock_event_device clockevent = {
+        .name           = "vt8500_timer",
+        .features       = CLOCK_EVT_FEAT_ONESHOT,
+        .rating         = 200,
+        .set_next_event = vt8500_timer_set_next_event,
+        .set_mode       = vt8500_timer_set_mode,
+};
+
+static irqreturn_t vt8500_timer_interrupt(int irq, void *dev_id)
+{
+        struct clock_event_device *evt = dev_id;
+        writel(0xf, regbase + TIMER_STATUS_VAL);
+        evt->event_handler(evt);
+
+        return IRQ_HANDLED;
+}
+
+static struct irqaction irq = {
+        .name    = "vt8500_timer",
+        .flags   = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+        .handler = vt8500_timer_interrupt,
+        .dev_id  = &clockevent,
+};
+
+static struct of_device_id vt8500_timer_ids[] = {
+        { .compatible = "via,vt8500-timer" },
+        { }
+};
+
+static void __init vt8500_timer_init(void)
+{
+        struct device_node *np;
+        int timer_irq;
+
+        np = of_find_matching_node(NULL, vt8500_timer_ids);
+        if (!np) {
+                pr_err("%s: Timer description missing from Device Tree\n",
+                                                                __func__);
+                return;
+        }
+        regbase = of_iomap(np, 0);
+        if (!regbase) {
+                pr_err("%s: Missing iobase description in Device Tree\n",
+                                                                __func__);
+                of_node_put(np);
+                return;
+        }
+        timer_irq = irq_of_parse_and_map(np, 0);
+        if (!timer_irq) {
+                pr_err("%s: Missing irq description in Device Tree\n",
+                                                                __func__);
+                of_node_put(np);
+                return;
+        }
+
+        writel(1, regbase + TIMER_CTRL_VAL);
+        writel(0xf, regbase + TIMER_STATUS_VAL);
+        writel(~0, regbase + TIMER_MATCH_VAL);
+
+        if (clocksource_register_hz(&clocksource, VT8500_TIMER_HZ))
+                pr_err("%s: vt8500_timer_init: clocksource_register failed for %s\n",
+                                        __func__, clocksource.name);
+
+        clockevent.cpumask = cpumask_of(0);
+
+        if (setup_irq(timer_irq, &irq))
+                pr_err("%s: setup_irq failed for %s\n", __func__,
+                                                        clockevent.name);
+        clockevents_config_and_register(&clockevent, VT8500_TIMER_HZ,
+                                        4, 0xf0000000);
+}
+
+CLOCKSOURCE_OF_DECLARE(vt8500, "via,vt8500-timer", vt8500_timer_init)