* 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>
#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");
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 */
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:
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;
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;
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;
}
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:
#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);
/*
} 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;
}
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
*/
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()) {
} 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
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;
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();
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:
--- /dev/null
+/*
+ * (C) Copyright 2009 Intel Corporation
+ * Author: Jacob Pan (jacob.jun.pan@intel.com)
+ *
+ * Shared with ARM platforms, Jamie Iles, Picochip 2011
+ *
+ * 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.
+ *
+ * Support for the Synopsys DesignWare APB Timers.
+ */
+#include <linux/dw_apb_timer.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#define APBT_MIN_PERIOD 4
+#define APBT_MIN_DELTA_USEC 200
+
+#define APBTMR_N_LOAD_COUNT 0x00
+#define APBTMR_N_CURRENT_VALUE 0x04
+#define APBTMR_N_CONTROL 0x08
+#define APBTMR_N_EOI 0x0c
+#define APBTMR_N_INT_STATUS 0x10
+
+#define APBTMRS_INT_STATUS 0xa0
+#define APBTMRS_EOI 0xa4
+#define APBTMRS_RAW_INT_STATUS 0xa8
+#define APBTMRS_COMP_VERSION 0xac
+
+#define APBTMR_CONTROL_ENABLE (1 << 0)
+/* 1: periodic, 0:free running. */
+#define APBTMR_CONTROL_MODE_PERIODIC (1 << 1)
+#define APBTMR_CONTROL_INT (1 << 2)
+
+static inline struct dw_apb_clock_event_device *
+ced_to_dw_apb_ced(struct clock_event_device *evt)
+{
+ return container_of(evt, struct dw_apb_clock_event_device, ced);
+}
+
+static inline struct dw_apb_clocksource *
+clocksource_to_dw_apb_clocksource(struct clocksource *cs)
+{
+ return container_of(cs, struct dw_apb_clocksource, cs);
+}
+
+static unsigned long apbt_readl(struct dw_apb_timer *timer, unsigned long offs)
+{
+ return readl(timer->base + offs);
+}
+
+static void apbt_writel(struct dw_apb_timer *timer, unsigned long val,
+ unsigned long offs)
+{
+ writel(val, timer->base + offs);
+}
+
+static void apbt_disable_int(struct dw_apb_timer *timer)
+{
+ unsigned long ctrl = apbt_readl(timer, APBTMR_N_CONTROL);
+
+ ctrl |= APBTMR_CONTROL_INT;
+ apbt_writel(timer, ctrl, APBTMR_N_CONTROL);
+}
+
+/**
+ * dw_apb_clockevent_pause() - stop the clock_event_device from running
+ *
+ * @dw_ced: The APB clock to stop generating events.
+ */
+void dw_apb_clockevent_pause(struct dw_apb_clock_event_device *dw_ced)
+{
+ disable_irq(dw_ced->timer.irq);
+ apbt_disable_int(&dw_ced->timer);
+}
+
+static void apbt_eoi(struct dw_apb_timer *timer)
+{
+ apbt_readl(timer, APBTMR_N_EOI);
+}
+
+static irqreturn_t dw_apb_clockevent_irq(int irq, void *data)
+{
+ struct clock_event_device *evt = data;
+ struct dw_apb_clock_event_device *dw_ced = ced_to_dw_apb_ced(evt);
+
+ if (!evt->event_handler) {
+ pr_info("Spurious APBT timer interrupt %d", irq);
+ return IRQ_NONE;
+ }
+
+ if (dw_ced->eoi)
+ dw_ced->eoi(&dw_ced->timer);
+
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static void apbt_enable_int(struct dw_apb_timer *timer)
+{
+ unsigned long ctrl = apbt_readl(timer, APBTMR_N_CONTROL);
+ /* clear pending intr */
+ apbt_readl(timer, APBTMR_N_EOI);
+ ctrl &= ~APBTMR_CONTROL_INT;
+ apbt_writel(timer, ctrl, APBTMR_N_CONTROL);
+}
+
+static void apbt_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ unsigned long ctrl;
+ unsigned long period;
+ struct dw_apb_clock_event_device *dw_ced = ced_to_dw_apb_ced(evt);
+
+ pr_debug("%s CPU %d mode=%d\n", __func__, first_cpu(*evt->cpumask),
+ mode);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ period = DIV_ROUND_UP(dw_ced->timer.freq, HZ);
+ ctrl = apbt_readl(&dw_ced->timer, APBTMR_N_CONTROL);
+ ctrl |= APBTMR_CONTROL_MODE_PERIODIC;
+ apbt_writel(&dw_ced->timer, 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(&dw_ced->timer, ctrl, APBTMR_N_CONTROL);
+ udelay(1);
+ pr_debug("Setting clock period %lu for HZ %d\n", period, HZ);
+ apbt_writel(&dw_ced->timer, period, APBTMR_N_LOAD_COUNT);
+ ctrl |= APBTMR_CONTROL_ENABLE;
+ apbt_writel(&dw_ced->timer, ctrl, APBTMR_N_CONTROL);
+ break;
+
+ case CLOCK_EVT_MODE_ONESHOT:
+ ctrl = apbt_readl(&dw_ced->timer, 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(&dw_ced->timer, ctrl, APBTMR_N_CONTROL);
+ /* write again to set free running mode */
+ apbt_writel(&dw_ced->timer, ctrl, APBTMR_N_CONTROL);
+
+ /*
+ * DW APB p. 46, load counter with all 1s before starting free
+ * running mode.
+ */
+ apbt_writel(&dw_ced->timer, ~0, APBTMR_N_LOAD_COUNT);
+ ctrl &= ~APBTMR_CONTROL_INT;
+ ctrl |= APBTMR_CONTROL_ENABLE;
+ apbt_writel(&dw_ced->timer, ctrl, APBTMR_N_CONTROL);
+ break;
+
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ ctrl = apbt_readl(&dw_ced->timer, APBTMR_N_CONTROL);
+ ctrl &= ~APBTMR_CONTROL_ENABLE;
+ apbt_writel(&dw_ced->timer, ctrl, APBTMR_N_CONTROL);
+ break;
+
+ case CLOCK_EVT_MODE_RESUME:
+ apbt_enable_int(&dw_ced->timer);
+ break;
+ }
+}
+
+static int apbt_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ unsigned long ctrl;
+ struct dw_apb_clock_event_device *dw_ced = ced_to_dw_apb_ced(evt);
+
+ /* Disable timer */
+ ctrl = apbt_readl(&dw_ced->timer, APBTMR_N_CONTROL);
+ ctrl &= ~APBTMR_CONTROL_ENABLE;
+ apbt_writel(&dw_ced->timer, ctrl, APBTMR_N_CONTROL);
+ /* write new count */
+ apbt_writel(&dw_ced->timer, delta, APBTMR_N_LOAD_COUNT);
+ ctrl |= APBTMR_CONTROL_ENABLE;
+ apbt_writel(&dw_ced->timer, ctrl, APBTMR_N_CONTROL);
+
+ return 0;
+}
+
+/**
+ * dw_apb_clockevent_init() - use an APB timer as a clock_event_device
+ *
+ * @cpu: The CPU the events will be targeted at.
+ * @name: The name used for the timer and the IRQ for it.
+ * @rating: The rating to give the timer.
+ * @base: I/O base for the timer registers.
+ * @irq: The interrupt number to use for the timer.
+ * @freq: The frequency that the timer counts at.
+ *
+ * This creates a clock_event_device for using with the generic clock layer
+ * but does not start and register it. This should be done with
+ * dw_apb_clockevent_register() as the next step. If this is the first time
+ * it has been called for a timer then the IRQ will be requested, if not it
+ * just be enabled to allow CPU hotplug to avoid repeatedly requesting and
+ * releasing the IRQ.
+ */
+struct dw_apb_clock_event_device *
+dw_apb_clockevent_init(int cpu, const char *name, unsigned rating,
+ void __iomem *base, int irq, unsigned long freq)
+{
+ struct dw_apb_clock_event_device *dw_ced =
+ kzalloc(sizeof(*dw_ced), GFP_KERNEL);
+ int err;
+
+ if (!dw_ced)
+ return NULL;
+
+ dw_ced->timer.base = base;
+ dw_ced->timer.irq = irq;
+ dw_ced->timer.freq = freq;
+
+ clockevents_calc_mult_shift(&dw_ced->ced, freq, APBT_MIN_PERIOD);
+ dw_ced->ced.max_delta_ns = clockevent_delta2ns(0x7fffffff,
+ &dw_ced->ced);
+ dw_ced->ced.min_delta_ns = clockevent_delta2ns(5000, &dw_ced->ced);
+ dw_ced->ced.cpumask = cpumask_of(cpu);
+ dw_ced->ced.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+ dw_ced->ced.set_mode = apbt_set_mode;
+ dw_ced->ced.set_next_event = apbt_next_event;
+ dw_ced->ced.irq = dw_ced->timer.irq;
+ dw_ced->ced.rating = rating;
+ dw_ced->ced.name = name;
+
+ dw_ced->irqaction.name = dw_ced->ced.name;
+ dw_ced->irqaction.handler = dw_apb_clockevent_irq;
+ dw_ced->irqaction.dev_id = &dw_ced->ced;
+ dw_ced->irqaction.irq = irq;
+ dw_ced->irqaction.flags = IRQF_TIMER | IRQF_IRQPOLL |
+ IRQF_NOBALANCING |
+ IRQF_DISABLED;
+
+ dw_ced->eoi = apbt_eoi;
+ err = setup_irq(irq, &dw_ced->irqaction);
+ if (err) {
+ pr_err("failed to request timer irq\n");
+ kfree(dw_ced);
+ dw_ced = NULL;
+ }
+
+ return dw_ced;
+}
+
+/**
+ * dw_apb_clockevent_resume() - resume a clock that has been paused.
+ *
+ * @dw_ced: The APB clock to resume.
+ */
+void dw_apb_clockevent_resume(struct dw_apb_clock_event_device *dw_ced)
+{
+ enable_irq(dw_ced->timer.irq);
+}
+
+/**
+ * dw_apb_clockevent_stop() - stop the clock_event_device and release the IRQ.
+ *
+ * @dw_ced: The APB clock to stop generating the events.
+ */
+void dw_apb_clockevent_stop(struct dw_apb_clock_event_device *dw_ced)
+{
+ free_irq(dw_ced->timer.irq, &dw_ced->ced);
+}
+
+/**
+ * dw_apb_clockevent_register() - register the clock with the generic layer
+ *
+ * @dw_ced: The APB clock to register as a clock_event_device.
+ */
+void dw_apb_clockevent_register(struct dw_apb_clock_event_device *dw_ced)
+{
+ apbt_writel(&dw_ced->timer, 0, APBTMR_N_CONTROL);
+ clockevents_register_device(&dw_ced->ced);
+ apbt_enable_int(&dw_ced->timer);
+}
+
+/**
+ * dw_apb_clocksource_start() - start the clocksource counting.
+ *
+ * @dw_cs: The clocksource to start.
+ *
+ * This is used to start the clocksource before registration and can be used
+ * to enable calibration of timers.
+ */
+void dw_apb_clocksource_start(struct dw_apb_clocksource *dw_cs)
+{
+ /*
+ * start count down from 0xffff_ffff. this is done by toggling the
+ * enable bit then load initial load count to ~0.
+ */
+ unsigned long ctrl = apbt_readl(&dw_cs->timer, APBTMR_N_CONTROL);
+
+ ctrl &= ~APBTMR_CONTROL_ENABLE;
+ apbt_writel(&dw_cs->timer, ctrl, APBTMR_N_CONTROL);
+ apbt_writel(&dw_cs->timer, ~0, APBTMR_N_LOAD_COUNT);
+ /* enable, mask interrupt */
+ ctrl &= ~APBTMR_CONTROL_MODE_PERIODIC;
+ ctrl |= (APBTMR_CONTROL_ENABLE | APBTMR_CONTROL_INT);
+ apbt_writel(&dw_cs->timer, ctrl, APBTMR_N_CONTROL);
+ /* read it once to get cached counter value initialized */
+ dw_apb_clocksource_read(dw_cs);
+}
+
+static cycle_t __apbt_read_clocksource(struct clocksource *cs)
+{
+ unsigned long current_count;
+ struct dw_apb_clocksource *dw_cs =
+ clocksource_to_dw_apb_clocksource(cs);
+
+ current_count = apbt_readl(&dw_cs->timer, APBTMR_N_CURRENT_VALUE);
+
+ return (cycle_t)~current_count;
+}
+
+static void apbt_restart_clocksource(struct clocksource *cs)
+{
+ struct dw_apb_clocksource *dw_cs =
+ clocksource_to_dw_apb_clocksource(cs);
+
+ dw_apb_clocksource_start(dw_cs);
+}
+
+/**
+ * dw_apb_clocksource_init() - use an APB timer as a clocksource.
+ *
+ * @rating: The rating to give the clocksource.
+ * @name: The name for the clocksource.
+ * @base: The I/O base for the timer registers.
+ * @freq: The frequency that the timer counts at.
+ *
+ * This creates a clocksource using an APB timer but does not yet register it
+ * with the clocksource system. This should be done with
+ * dw_apb_clocksource_register() as the next step.
+ */
+struct dw_apb_clocksource *
+dw_apb_clocksource_init(unsigned rating, char *name, void __iomem *base,
+ unsigned long freq)
+{
+ struct dw_apb_clocksource *dw_cs = kzalloc(sizeof(*dw_cs), GFP_KERNEL);
+
+ if (!dw_cs)
+ return NULL;
+
+ dw_cs->timer.base = base;
+ dw_cs->timer.freq = freq;
+ dw_cs->cs.name = name;
+ dw_cs->cs.rating = rating;
+ dw_cs->cs.read = __apbt_read_clocksource;
+ dw_cs->cs.mask = CLOCKSOURCE_MASK(32);
+ dw_cs->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+ dw_cs->cs.resume = apbt_restart_clocksource;
+
+ return dw_cs;
+}
+
+/**
+ * dw_apb_clocksource_register() - register the APB clocksource.
+ *
+ * @dw_cs: The clocksource to register.
+ */
+void dw_apb_clocksource_register(struct dw_apb_clocksource *dw_cs)
+{
+ clocksource_register_hz(&dw_cs->cs, dw_cs->timer.freq);
+}
+
+/**
+ * dw_apb_clocksource_read() - read the current value of a clocksource.
+ *
+ * @dw_cs: The clocksource to read.
+ */
+cycle_t dw_apb_clocksource_read(struct dw_apb_clocksource *dw_cs)
+{
+ return (cycle_t)~apbt_readl(&dw_cs->timer, APBTMR_N_CURRENT_VALUE);
+}
+
+/**
+ * dw_apb_clocksource_unregister() - unregister and free a clocksource.
+ *
+ * @dw_cs: The clocksource to unregister/free.
+ */
+void dw_apb_clocksource_unregister(struct dw_apb_clocksource *dw_cs)
+{
+ clocksource_unregister(&dw_cs->cs);
+
+ kfree(dw_cs);
+}
projects / ~andy / linux / commitdiff