diff options
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/apb_timer.h | 22 | ||||
| -rw-r--r-- | arch/x86/kernel/apb_timer.c | 409 | ||||
| -rw-r--r-- | drivers/clocksource/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/dw_apb_timer.c | 401 | ||||
| -rw-r--r-- | include/linux/dw_apb_timer.h | 56 |
7 files changed, 533 insertions, 360 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5f60ea190d5b..c3e03e46bc64 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -623,6 +623,7 @@ config HPET_EMULATE_RTC config APB_TIMER def_bool y if MRST prompt "Langwell APB Timer Support" if X86_MRST + select DW_APB_TIMER help APB timer is the replacement for 8254, HPET on X86 MID platforms. The APBT provides a stable time base on SMP diff --git a/arch/x86/include/asm/apb_timer.h b/arch/x86/include/asm/apb_timer.h index 082cf8184935..0acbac299e49 100644 --- a/arch/x86/include/asm/apb_timer.h +++ b/arch/x86/include/asm/apb_timer.h @@ -18,24 +18,6 @@ #ifdef CONFIG_APB_TIMER -/* Langwell DW APB timer registers */ -#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 APBTMRS_REG_SIZE 0x14 - -/* register bits */ -#define APBTMR_CONTROL_ENABLE (1<<0) -#define APBTMR_CONTROL_MODE_PERIODIC (1<<1) /*1: periodic 0:free running */ -#define APBTMR_CONTROL_INT (1<<2) - /* default memory mapped register base */ #define LNW_SCU_ADDR 0xFF100000 #define LNW_EXT_TIMER_OFFSET 0x1B800 @@ -43,8 +25,8 @@ #define LNW_EXT_TIMER_PGOFFSET 0x800 /* APBT clock speed range from PCLK to fabric base, 25-100MHz */ -#define APBT_MAX_FREQ 50 -#define APBT_MIN_FREQ 1 +#define APBT_MAX_FREQ 50000000 +#define APBT_MIN_FREQ 1000000 #define APBT_MMAP_SIZE 1024 #define APBT_DEV_USED 1 diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c index 2b6630d75e17..afdc3f756dea 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> @@ -46,75 +43,46 @@ #include <asm/mrst.h> #include <asm/time.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"); @@ -126,21 +94,18 @@ 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 */ @@ -149,9 +114,14 @@ 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: @@ -173,82 +143,6 @@ 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; @@ -261,45 +155,21 @@ 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; @@ -317,52 +187,34 @@ 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; } @@ -385,13 +237,12 @@ 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: @@ -416,116 +267,16 @@ 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); /* @@ -540,10 +291,10 @@ 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; } @@ -567,10 +318,7 @@ 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 @@ -578,7 +326,7 @@ 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()) { @@ -604,30 +352,20 @@ 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 @@ -639,17 +377,8 @@ 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; @@ -658,31 +387,31 @@ 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(); @@ -694,7 +423,7 @@ 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: diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index d8d3e02b912c..34e9c4f88926 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -12,3 +12,6 @@ config CLKBLD_I8253 config CLKSRC_MMIO bool + +config DW_APB_TIMER + bool diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 7922a0cfc99f..85ad1646a7b7 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o obj-$(CONFIG_CLKBLD_I8253) += i8253.o obj-$(CONFIG_CLKSRC_MMIO) += mmio.o +obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o diff --git a/drivers/clocksource/dw_apb_timer.c b/drivers/clocksource/dw_apb_timer.c new file mode 100644 index 000000000000..580f870541a3 --- /dev/null +++ b/drivers/clocksource/dw_apb_timer.c @@ -0,0 +1,401 @@ +/* + * (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); +} diff --git a/include/linux/dw_apb_timer.h b/include/linux/dw_apb_timer.h new file mode 100644 index 000000000000..49638ea3b776 --- /dev/null +++ b/include/linux/dw_apb_timer.h @@ -0,0 +1,56 @@ +/* + * (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. + */ +#ifndef __DW_APB_TIMER_H__ +#define __DW_APB_TIMER_H__ + +#include <linux/clockchips.h> +#include <linux/clocksource.h> +#include <linux/interrupt.h> + +#define APBTMRS_REG_SIZE 0x14 + +struct dw_apb_timer { + void __iomem *base; + unsigned long freq; + int irq; +}; + +struct dw_apb_clock_event_device { + struct clock_event_device ced; + struct dw_apb_timer timer; + struct irqaction irqaction; + void (*eoi)(struct dw_apb_timer *); +}; + +struct dw_apb_clocksource { + struct dw_apb_timer timer; + struct clocksource cs; +}; + +void dw_apb_clockevent_register(struct dw_apb_clock_event_device *dw_ced); +void dw_apb_clockevent_pause(struct dw_apb_clock_event_device *dw_ced); +void dw_apb_clockevent_resume(struct dw_apb_clock_event_device *dw_ced); +void dw_apb_clockevent_stop(struct dw_apb_clock_event_device *dw_ced); + +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_clocksource * +dw_apb_clocksource_init(unsigned rating, char *name, void __iomem *base, + unsigned long freq); +void dw_apb_clocksource_register(struct dw_apb_clocksource *dw_cs); +void dw_apb_clocksource_start(struct dw_apb_clocksource *dw_cs); +cycle_t dw_apb_clocksource_read(struct dw_apb_clocksource *dw_cs); +void dw_apb_clocksource_unregister(struct dw_apb_clocksource *dw_cs); + +#endif /* __DW_APB_TIMER_H__ */ |