clocksource: apb: Share APB timer code with other platforms

The APB timers are an IP block from Synopsys (DesignWare APB timers)
and are also found in other systems including ARM SoC's.  This patch
adds functions for creating clock_event_devices and clocksources from
APB timers but does not do the resource allocation.  This is handled
in a higher layer to allow the timers to be created from multiple
methods such as platform_devices.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

1 files changed, 69 insertions, 340 deletions

diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c
index 289e92862fd9..033d3ecc5744 100644
--- a/arch/x86/kernel/apb_timer.c
+++ b/arch/x86/kernel/apb_timer.c
@@ -27,15 +27,12 @@
  * timer, but by default APB timer has higher rating than local APIC timers.
  */
 
-#include <linux/clocksource.h>
-#include <linux/clockchips.h>
 #include <linux/delay.h>
+#include <linux/dw_apb_timer.h>
 #include <linux/errno.h>
 #include <linux/init.h>
-#include <linux/sysdev.h>
 #include <linux/slab.h>
 #include <linux/pm.h>
-#include <linux/pci.h>
 #include <linux/sfi.h>
 #include <linux/interrupt.h>
 #include <linux/cpu.h>
@@ -45,75 +42,46 @@
 #include <asm/apb_timer.h>
 #include <asm/mrst.h>
 
-#define APBT_MASK                       CLOCKSOURCE_MASK(32)
-#define APBT_SHIFT                      22
 #define APBT_CLOCKEVENT_RATING          110
 #define APBT_CLOCKSOURCE_RATING         250
-#define APBT_MIN_DELTA_USEC             200
 
-#define EVT_TO_APBT_DEV(evt) container_of(evt, struct apbt_dev, evt)
 #define APBT_CLOCKEVENT0_NUM   (0)
-#define APBT_CLOCKEVENT1_NUM   (1)
 #define APBT_CLOCKSOURCE_NUM   (2)
 
-static unsigned long apbt_address;
+static phys_addr_t apbt_address;
 static int apb_timer_block_enabled;
 static void __iomem *apbt_virt_address;
-static int phy_cs_timer_id;
 
 /*
  * Common DW APB timer info
  */
-static uint64_t apbt_freq;
-
-static void apbt_set_mode(enum clock_event_mode mode,
-                          struct clock_event_device *evt);
-static int apbt_next_event(unsigned long delta,
-                           struct clock_event_device *evt);
-static cycle_t apbt_read_clocksource(struct clocksource *cs);
-static void apbt_restart_clocksource(struct clocksource *cs);
+static unsigned long apbt_freq;
 
 struct apbt_dev {
-        struct clock_event_device evt;
-        unsigned int num;
-        int cpu;
-        unsigned int irq;
-        unsigned int tick;
-        unsigned int count;
-        unsigned int flags;
-        char name[10];
+        struct dw_apb_clock_event_device        *timer;
+        unsigned int                            num;
+        int                                     cpu;
+        unsigned int                            irq;
+        char                                    name[10];
 };
 
-static DEFINE_PER_CPU(struct apbt_dev, cpu_apbt_dev);
+static struct dw_apb_clocksource *clocksource_apbt;
 
-#ifdef CONFIG_SMP
-static unsigned int apbt_num_timers_used;
-static struct apbt_dev *apbt_devs;
-#endif
-
-static  inline unsigned long apbt_readl_reg(unsigned long a)
+static inline void __iomem *adev_virt_addr(struct apbt_dev *adev)
 {
-        return readl(apbt_virt_address + a);
+        return apbt_virt_address + adev->num * APBTMRS_REG_SIZE;
 }
 
-static inline void apbt_writel_reg(unsigned long d, unsigned long a)
-{
-        writel(d, apbt_virt_address + a);
-}
-
-static inline unsigned long apbt_readl(int n, unsigned long a)
-{
-        return readl(apbt_virt_address + a + n * APBTMRS_REG_SIZE);
-}
+static DEFINE_PER_CPU(struct apbt_dev, cpu_apbt_dev);
 
-static inline void apbt_writel(int n, unsigned long d, unsigned long a)
-{
-        writel(d, apbt_virt_address + a + n * APBTMRS_REG_SIZE);
-}
+#ifdef CONFIG_SMP
+static unsigned int apbt_num_timers_used;
+#endif
 
 static inline void apbt_set_mapping(void)
 {
         struct sfi_timer_table_entry *mtmr;
+        int phy_cs_timer_id = 0;
 
         if (apbt_virt_address) {
                 pr_debug("APBT base already mapped\n");
@@ -125,21 +93,18 @@ static inline void apbt_set_mapping(void)
                        APBT_CLOCKEVENT0_NUM);
                 return;
         }
-        apbt_address = (unsigned long)mtmr->phys_addr;
+        apbt_address = (phys_addr_t)mtmr->phys_addr;
         if (!apbt_address) {
                 printk(KERN_WARNING "No timer base from SFI, use default\n");
                 apbt_address = APBT_DEFAULT_BASE;
         }
         apbt_virt_address = ioremap_nocache(apbt_address, APBT_MMAP_SIZE);
-        if (apbt_virt_address) {
-                pr_debug("Mapped APBT physical addr %p at virtual addr %p\n",\
-                         (void *)apbt_address, (void *)apbt_virt_address);
-        } else {
-                pr_debug("Failed mapping APBT phy address at %p\n",\
-                         (void *)apbt_address);
+        if (!apbt_virt_address) {
+                pr_debug("Failed mapping APBT phy address at %lu\n",\
+                         (unsigned long)apbt_address);
                 goto panic_noapbt;
         }
-        apbt_freq = mtmr->freq_hz / USEC_PER_SEC;
+        apbt_freq = mtmr->freq_hz;
         sfi_free_mtmr(mtmr);
 
         /* Now figure out the physical timer id for clocksource device */
@@ -148,9 +113,14 @@ static inline void apbt_set_mapping(void)
                 goto panic_noapbt;
 
         /* Now figure out the physical timer id */
-        phy_cs_timer_id = (unsigned int)(mtmr->phys_addr & 0xff)
-                / APBTMRS_REG_SIZE;
-        pr_debug("Use timer %d for clocksource\n", phy_cs_timer_id);
+        pr_debug("Use timer %d for clocksource\n",
+                 (int)(mtmr->phys_addr & 0xff) / APBTMRS_REG_SIZE);
+        phy_cs_timer_id = (unsigned int)(mtmr->phys_addr & 0xff) /
+                APBTMRS_REG_SIZE;
+
+        clocksource_apbt = dw_apb_clocksource_init(APBT_CLOCKSOURCE_RATING,
+                "apbt0", apbt_virt_address + phy_cs_timer_id *
+                APBTMRS_REG_SIZE, apbt_freq);
         return;
 
 panic_noapbt:
@@ -172,82 +142,6 @@ static inline int is_apbt_capable(void)
         return apbt_virt_address ? 1 : 0;
 }
 
-static struct clocksource clocksource_apbt = {
-        .name           = "apbt",
-        .rating         = APBT_CLOCKSOURCE_RATING,
-        .read           = apbt_read_clocksource,
-        .mask           = APBT_MASK,
-        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
-        .resume         = apbt_restart_clocksource,
-};
-
-/* boot APB clock event device */
-static struct clock_event_device apbt_clockevent = {
-        .name           = "apbt0",
-        .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-        .set_mode       = apbt_set_mode,
-        .set_next_event = apbt_next_event,
-        .shift          = APBT_SHIFT,
-        .irq            = 0,
-        .rating         = APBT_CLOCKEVENT_RATING,
-};
-
-/*
- * start count down from 0xffff_ffff. this is done by toggling the enable bit
- * then load initial load count to ~0.
- */
-static void apbt_start_counter(int n)
-{
-        unsigned long ctrl = apbt_readl(n, APBTMR_N_CONTROL);
-
-        ctrl &= ~APBTMR_CONTROL_ENABLE;
-        apbt_writel(n, ctrl, APBTMR_N_CONTROL);
-        apbt_writel(n, ~0, APBTMR_N_LOAD_COUNT);
-        /* enable, mask interrupt */
-        ctrl &= ~APBTMR_CONTROL_MODE_PERIODIC;
-        ctrl |= (APBTMR_CONTROL_ENABLE | APBTMR_CONTROL_INT);
-        apbt_writel(n, ctrl, APBTMR_N_CONTROL);
-        /* read it once to get cached counter value initialized */
-        apbt_read_clocksource(&clocksource_apbt);
-}
-
-static irqreturn_t apbt_interrupt_handler(int irq, void *data)
-{
-        struct apbt_dev *dev = (struct apbt_dev *)data;
-        struct clock_event_device *aevt = &dev->evt;
-
-        if (!aevt->event_handler) {
-                printk(KERN_INFO "Spurious APBT timer interrupt on %d\n",
-                       dev->num);
-                return IRQ_NONE;
-        }
-        aevt->event_handler(aevt);
-        return IRQ_HANDLED;
-}
-
-static void apbt_restart_clocksource(struct clocksource *cs)
-{
-        apbt_start_counter(phy_cs_timer_id);
-}
-
-static void apbt_enable_int(int n)
-{
-        unsigned long ctrl = apbt_readl(n, APBTMR_N_CONTROL);
-        /* clear pending intr */
-        apbt_readl(n, APBTMR_N_EOI);
-        ctrl &= ~APBTMR_CONTROL_INT;
-        apbt_writel(n, ctrl, APBTMR_N_CONTROL);
-}
-
-static void apbt_disable_int(int n)
-{
-        unsigned long ctrl = apbt_readl(n, APBTMR_N_CONTROL);
-
-        ctrl |= APBTMR_CONTROL_INT;
-        apbt_writel(n, ctrl, APBTMR_N_CONTROL);
-}
-
-
 static int __init apbt_clockevent_register(void)
 {
         struct sfi_timer_table_entry *mtmr;
@@ -260,45 +154,21 @@ static int __init apbt_clockevent_register(void)
                 return -ENODEV;
         }
 
-        /*
-         * We need to calculate the scaled math multiplication factor for
-         * nanosecond to apbt tick conversion.
-         * mult = (nsec/cycle)*2^APBT_SHIFT
-         */
-        apbt_clockevent.mult = div_sc((unsigned long) mtmr->freq_hz
-                                      , NSEC_PER_SEC, APBT_SHIFT);
-
-        /* Calculate the min / max delta */
-        apbt_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
-                                                           &apbt_clockevent);
-        apbt_clockevent.min_delta_ns = clockevent_delta2ns(
-                APBT_MIN_DELTA_USEC*apbt_freq,
-                &apbt_clockevent);
-        /*
-         * Start apbt with the boot cpu mask and make it
-         * global if not used for per cpu timer.
-         */
-        apbt_clockevent.cpumask = cpumask_of(smp_processor_id());
         adev->num = smp_processor_id();
-        memcpy(&adev->evt, &apbt_clockevent, sizeof(struct clock_event_device));
+        adev->timer = dw_apb_clockevent_init(smp_processor_id(), "apbt0",
+                mrst_timer_options == MRST_TIMER_LAPIC_APBT ?
+                APBT_CLOCKEVENT_RATING - 100 : APBT_CLOCKEVENT_RATING,
+                adev_virt_addr(adev), 0, apbt_freq);
+        /* Firmware does EOI handling for us. */
+        adev->timer->eoi = NULL;
 
         if (mrst_timer_options == MRST_TIMER_LAPIC_APBT) {
-                adev->evt.rating = APBT_CLOCKEVENT_RATING - 100;
-                global_clock_event = &adev->evt;
+                global_clock_event = &adev->timer->ced;
                 printk(KERN_DEBUG "%s clockevent registered as global\n",
                        global_clock_event->name);
         }
 
-        if (request_irq(apbt_clockevent.irq, apbt_interrupt_handler,
-                        IRQF_TIMER | IRQF_DISABLED | IRQF_NOBALANCING,
-                        apbt_clockevent.name, adev)) {
-                printk(KERN_ERR "Failed request IRQ for APBT%d\n",
-                       apbt_clockevent.irq);
-        }
-
-        clockevents_register_device(&adev->evt);
-        /* Start APBT 0 interrupts */
-        apbt_enable_int(APBT_CLOCKEVENT0_NUM);
+        dw_apb_clockevent_register(adev->timer);
 
         sfi_free_mtmr(mtmr);
         return 0;
@@ -316,52 +186,34 @@ static void apbt_setup_irq(struct apbt_dev *adev)
         irq_set_affinity(adev->irq, cpumask_of(adev->cpu));
         /* APB timer irqs are set up as mp_irqs, timer is edge type */
         __irq_set_handler(adev->irq, handle_edge_irq, 0, "edge");
-
-        if (system_state == SYSTEM_BOOTING) {
-                if (request_irq(adev->irq, apbt_interrupt_handler,
-                                        IRQF_TIMER | IRQF_DISABLED |
-                                        IRQF_NOBALANCING,
-                                        adev->name, adev)) {
-                        printk(KERN_ERR "Failed request IRQ for APBT%d\n",
-                               adev->num);
-                }
-        } else
-                enable_irq(adev->irq);
 }
 
 /* Should be called with per cpu */
 void apbt_setup_secondary_clock(void)
 {
         struct apbt_dev *adev;
-        struct clock_event_device *aevt;
         int cpu;
 
         /* Don't register boot CPU clockevent */
         cpu = smp_processor_id();
         if (!cpu)
                 return;
-        /*
-         * We need to calculate the scaled math multiplication factor for
-         * nanosecond to apbt tick conversion.
-         * mult = (nsec/cycle)*2^APBT_SHIFT
-         */
-        printk(KERN_INFO "Init per CPU clockevent %d\n", cpu);
-        adev = &per_cpu(cpu_apbt_dev, cpu);
-        aevt = &adev->evt;
 
-        memcpy(aevt, &apbt_clockevent, sizeof(*aevt));
-        aevt->cpumask = cpumask_of(cpu);
-        aevt->name = adev->name;
-        aevt->mode = CLOCK_EVT_MODE_UNUSED;
+        adev = &__get_cpu_var(cpu_apbt_dev);
+        if (!adev->timer) {
+                adev->timer = dw_apb_clockevent_init(cpu, adev->name,
+                        APBT_CLOCKEVENT_RATING, adev_virt_addr(adev),
+                        adev->irq, apbt_freq);
+                adev->timer->eoi = NULL;
+        } else {
+                dw_apb_clockevent_resume(adev->timer);
+        }
 
-        printk(KERN_INFO "Registering CPU %d clockevent device %s, mask %08x\n",
-               cpu, aevt->name, *(u32 *)aevt->cpumask);
+        printk(KERN_INFO "Registering CPU %d clockevent device %s, cpu %08x\n",
+               cpu, adev->name, adev->cpu);
 
         apbt_setup_irq(adev);
-
-        clockevents_register_device(aevt);
-
-        apbt_enable_int(cpu);
+        dw_apb_clockevent_register(adev->timer);
 
         return;
 }
@@ -384,13 +236,12 @@ static int apbt_cpuhp_notify(struct notifier_block *n,
 
         switch (action & 0xf) {
         case CPU_DEAD:
-                disable_irq(adev->irq);
-                apbt_disable_int(cpu);
+                dw_apb_clockevent_pause(adev->timer);
                 if (system_state == SYSTEM_RUNNING) {
                         pr_debug("skipping APBT CPU %lu offline\n", cpu);
                 } else if (adev) {
                         pr_debug("APBT clockevent for cpu %lu offline\n", cpu);
-                        free_irq(adev->irq, adev);
+                        dw_apb_clockevent_stop(adev->timer);
                 }
                 break;
         default:
@@ -415,116 +266,16 @@ void apbt_setup_secondary_clock(void) {}
 
 #endif /* CONFIG_SMP */
 
-static void apbt_set_mode(enum clock_event_mode mode,
-                          struct clock_event_device *evt)
-{
-        unsigned long ctrl;
-        uint64_t delta;
-        int timer_num;
-        struct apbt_dev *adev = EVT_TO_APBT_DEV(evt);
-
-        BUG_ON(!apbt_virt_address);
-
-        timer_num = adev->num;
-        pr_debug("%s CPU %d timer %d mode=%d\n",
-                 __func__, first_cpu(*evt->cpumask), timer_num, mode);
-
-        switch (mode) {
-        case CLOCK_EVT_MODE_PERIODIC:
-                delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * apbt_clockevent.mult;
-                delta >>= apbt_clockevent.shift;
-                ctrl = apbt_readl(timer_num, APBTMR_N_CONTROL);
-                ctrl |= APBTMR_CONTROL_MODE_PERIODIC;
-                apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-                /*
-                 * DW APB p. 46, have to disable timer before load counter,
-                 * may cause sync problem.
-                 */
-                ctrl &= ~APBTMR_CONTROL_ENABLE;
-                apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-                udelay(1);
-                pr_debug("Setting clock period %d for HZ %d\n", (int)delta, HZ);
-                apbt_writel(timer_num, delta, APBTMR_N_LOAD_COUNT);
-                ctrl |= APBTMR_CONTROL_ENABLE;
-                apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-                break;
-                /* APB timer does not have one-shot mode, use free running mode */
-        case CLOCK_EVT_MODE_ONESHOT:
-                ctrl = apbt_readl(timer_num, APBTMR_N_CONTROL);
-                /*
-                 * set free running mode, this mode will let timer reload max
-                 * timeout which will give time (3min on 25MHz clock) to rearm
-                 * the next event, therefore emulate the one-shot mode.
-                 */
-                ctrl &= ~APBTMR_CONTROL_ENABLE;
-                ctrl &= ~APBTMR_CONTROL_MODE_PERIODIC;
-
-                apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-                /* write again to set free running mode */
-                apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-
-                /*
-                 * DW APB p. 46, load counter with all 1s before starting free
-                 * running mode.
-                 */
-                apbt_writel(timer_num, ~0, APBTMR_N_LOAD_COUNT);
-                ctrl &= ~APBTMR_CONTROL_INT;
-                ctrl |= APBTMR_CONTROL_ENABLE;
-                apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-                break;
-
-        case CLOCK_EVT_MODE_UNUSED:
-        case CLOCK_EVT_MODE_SHUTDOWN:
-                apbt_disable_int(timer_num);
-                ctrl = apbt_readl(timer_num, APBTMR_N_CONTROL);
-                ctrl &= ~APBTMR_CONTROL_ENABLE;
-                apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-                break;
-
-        case CLOCK_EVT_MODE_RESUME:
-                apbt_enable_int(timer_num);
-                break;
-        }
-}
-
-static int apbt_next_event(unsigned long delta,
-                           struct clock_event_device *evt)
-{
-        unsigned long ctrl;
-        int timer_num;
-
-        struct apbt_dev *adev = EVT_TO_APBT_DEV(evt);
-
-        timer_num = adev->num;
-        /* Disable timer */
-        ctrl = apbt_readl(timer_num, APBTMR_N_CONTROL);
-        ctrl &= ~APBTMR_CONTROL_ENABLE;
-        apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-        /* write new count */
-        apbt_writel(timer_num, delta, APBTMR_N_LOAD_COUNT);
-        ctrl |= APBTMR_CONTROL_ENABLE;
-        apbt_writel(timer_num, ctrl, APBTMR_N_CONTROL);
-        return 0;
-}
-
-static cycle_t apbt_read_clocksource(struct clocksource *cs)
-{
-        unsigned long current_count;
-
-        current_count = apbt_readl(phy_cs_timer_id, APBTMR_N_CURRENT_VALUE);
-        return (cycle_t)~current_count;
-}
-
 static int apbt_clocksource_register(void)
 {
         u64 start, now;
         cycle_t t1;
 
         /* Start the counter, use timer 2 as source, timer 0/1 for event */
-        apbt_start_counter(phy_cs_timer_id);
+        dw_apb_clocksource_start(clocksource_apbt);
 
         /* Verify whether apbt counter works */
-        t1 = apbt_read_clocksource(&clocksource_apbt);
+        t1 = dw_apb_clocksource_read(clocksource_apbt);
         rdtscll(start);
 
         /*
@@ -539,10 +290,10 @@ static int apbt_clocksource_register(void)
         } while ((now - start) < 200000UL);
 
         /* APBT is the only always on clocksource, it has to work! */
-        if (t1 == apbt_read_clocksource(&clocksource_apbt))
+        if (t1 == dw_apb_clocksource_read(clocksource_apbt))
                 panic("APBT counter not counting. APBT disabled\n");
 
-        clocksource_register_khz(&clocksource_apbt, (u32)apbt_freq*1000);
+        dw_apb_clocksource_register(clocksource_apbt);
 
         return 0;
 }
@@ -566,10 +317,7 @@ void __init apbt_time_init(void)
         if (apb_timer_block_enabled)
                 return;
         apbt_set_mapping();
-        if (apbt_virt_address) {
-                pr_debug("Found APBT version 0x%lx\n",\
-                         apbt_readl_reg(APBTMRS_COMP_VERSION));
-        } else
+        if (!apbt_virt_address)
                 goto out_noapbt;
         /*
          * Read the frequency and check for a sane value, for ESL model
@@ -577,7 +325,7 @@ void __init apbt_time_init(void)
          */
 
         if (apbt_freq < APBT_MIN_FREQ || apbt_freq > APBT_MAX_FREQ) {
-                pr_debug("APBT has invalid freq 0x%llx\n", apbt_freq);
+                pr_debug("APBT has invalid freq 0x%lx\n", apbt_freq);
                 goto out_noapbt;
         }
         if (apbt_clocksource_register()) {
@@ -603,30 +351,20 @@ void __init apbt_time_init(void)
         } else {
                 percpu_timer = 0;
                 apbt_num_timers_used = 1;
-                adev = &per_cpu(cpu_apbt_dev, 0);
-                adev->flags &= ~APBT_DEV_USED;
         }
         pr_debug("%s: %d APB timers used\n", __func__, apbt_num_timers_used);
 
         /* here we set up per CPU timer data structure */
-        apbt_devs = kzalloc(sizeof(struct apbt_dev) * apbt_num_timers_used,
-                            GFP_KERNEL);
-        if (!apbt_devs) {
-                printk(KERN_ERR "Failed to allocate APB timer devices\n");
-                return;
-        }
         for (i = 0; i < apbt_num_timers_used; i++) {
                 adev = &per_cpu(cpu_apbt_dev, i);
                 adev->num = i;
                 adev->cpu = i;
                 p_mtmr = sfi_get_mtmr(i);
-                if (p_mtmr) {
-                        adev->tick = p_mtmr->freq_hz;
+                if (p_mtmr)
                         adev->irq = p_mtmr->irq;
-                } else
+                else
                         printk(KERN_ERR "Failed to get timer for cpu %d\n", i);
-                adev->count = 0;
-                sprintf(adev->name, "apbt%d", i);
+                snprintf(adev->name, sizeof(adev->name) - 1, "apbt%d", i);
         }
 #endif
 
@@ -638,17 +376,8 @@ out_noapbt:
         panic("failed to enable APB timer\n");
 }
 
-static inline void apbt_disable(int n)
-{
-        if (is_apbt_capable()) {
-                unsigned long ctrl =  apbt_readl(n, APBTMR_N_CONTROL);
-                ctrl &= ~APBTMR_CONTROL_ENABLE;
-                apbt_writel(n, ctrl, APBTMR_N_CONTROL);
-        }
-}
-
 /* called before apb_timer_enable, use early map */
-unsigned long apbt_quick_calibrate()
+unsigned long apbt_quick_calibrate(void)
 {
         int i, scale;
         u64 old, new;
@@ -657,31 +386,31 @@ unsigned long apbt_quick_calibrate()
         u32 loop, shift;
 
         apbt_set_mapping();
-        apbt_start_counter(phy_cs_timer_id);
+        dw_apb_clocksource_start(clocksource_apbt);
 
         /* check if the timer can count down, otherwise return */
-        old = apbt_read_clocksource(&clocksource_apbt);
+        old = dw_apb_clocksource_read(clocksource_apbt);
         i = 10000;
         while (--i) {
-                if (old != apbt_read_clocksource(&clocksource_apbt))
+                if (old != dw_apb_clocksource_read(clocksource_apbt))
                         break;
         }
         if (!i)
                 goto failed;
 
         /* count 16 ms */
-        loop = (apbt_freq * 1000) << 4;
+        loop = (apbt_freq / 1000) << 4;
 
         /* restart the timer to ensure it won't get to 0 in the calibration */
-        apbt_start_counter(phy_cs_timer_id);
+        dw_apb_clocksource_start(clocksource_apbt);
 
-        old = apbt_read_clocksource(&clocksource_apbt);
+        old = dw_apb_clocksource_read(clocksource_apbt);
         old += loop;
 
         t1 = __native_read_tsc();
 
         do {
-                new = apbt_read_clocksource(&clocksource_apbt);
+                new = dw_apb_clocksource_read(clocksource_apbt);
         } while (new < old);
 
         t2 = __native_read_tsc();
@@ -693,7 +422,7 @@ unsigned long apbt_quick_calibrate()
                 return 0;
         }
         scale = (int)div_u64((t2 - t1), loop >> shift);
-        khz = (scale * apbt_freq * 1000) >> shift;
+        khz = (scale * (apbt_freq / 1000)) >> shift;
         printk(KERN_INFO "TSC freq calculated by APB timer is %lu khz\n", khz);
         return khz;
 failed: