diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | arch/metag/include/asm/clock.h | 51 | ||||
| -rw-r--r-- | arch/metag/include/asm/delay.h | 29 | ||||
| -rw-r--r-- | arch/metag/include/asm/mach/arch.h | 4 | ||||
| -rw-r--r-- | arch/metag/kernel/clock.c | 53 | ||||
| -rw-r--r-- | arch/metag/kernel/time.c | 15 | ||||
| -rw-r--r-- | drivers/clocksource/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/metag_generic.c | 198 | ||||
| -rw-r--r-- | include/clocksource/metag_generic.h | 21 |
10 files changed, 378 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 401145d7c5bb..749d76699ead 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5039,6 +5039,7 @@ S: Supported F: arch/metag/ F: Documentation/metag/ F: Documentation/devicetree/bindings/metag/ +F: drivers/clocksource/metag_generic.c MICROBLAZE ARCHITECTURE M: Michal Simek <monstr@monstr.eu> diff --git a/arch/metag/include/asm/clock.h b/arch/metag/include/asm/clock.h new file mode 100644 index 000000000000..3e2915a280c7 --- /dev/null +++ b/arch/metag/include/asm/clock.h @@ -0,0 +1,51 @@ +/* + * arch/metag/include/asm/clock.h + * + * Copyright (C) 2012 Imagination Technologies Ltd. + * + * 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. + */ + +#ifndef _METAG_CLOCK_H_ +#define _METAG_CLOCK_H_ + +#include <asm/mach/arch.h> + +/** + * struct meta_clock_desc - Meta Core clock callbacks. + * @get_core_freq: Get the frequency of the Meta core. If this is NULL, the + * core frequency will be determined like this: + * Meta 1: based on loops_per_jiffy. + * Meta 2: (EXPAND_TIMER_DIV + 1) MHz. + */ +struct meta_clock_desc { + unsigned long (*get_core_freq)(void); +}; + +extern struct meta_clock_desc _meta_clock; + +/* + * Set up the default clock, ensuring all callbacks are valid - only accessible + * during boot. + */ +void setup_meta_clocks(struct meta_clock_desc *desc); + +/** + * get_coreclock() - Get the frequency of the Meta core clock. + * + * Returns: The Meta core clock frequency in Hz. + */ +static inline unsigned long get_coreclock(void) +{ + /* + * Use the current clock callback. If set correctly this will provide + * the most accurate frequency as it can be calculated directly from the + * PLL configuration. otherwise a default callback will have been set + * instead. + */ + return _meta_clock.get_core_freq(); +} + +#endif /* _METAG_CLOCK_H_ */ diff --git a/arch/metag/include/asm/delay.h b/arch/metag/include/asm/delay.h new file mode 100644 index 000000000000..9c92f996957a --- /dev/null +++ b/arch/metag/include/asm/delay.h @@ -0,0 +1,29 @@ +#ifndef _METAG_DELAY_H +#define _METAG_DELAY_H + +/* + * Copyright (C) 1993 Linus Torvalds + * + * Delay routines calling functions in arch/metag/lib/delay.c + */ + +/* Undefined functions to get compile-time errors */ +extern void __bad_udelay(void); +extern void __bad_ndelay(void); + +extern void __udelay(unsigned long usecs); +extern void __ndelay(unsigned long nsecs); +extern void __const_udelay(unsigned long xloops); +extern void __delay(unsigned long loops); + +/* 0x10c7 is 2**32 / 1000000 (rounded up) */ +#define udelay(n) (__builtin_constant_p(n) ? \ + ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \ + __udelay(n)) + +/* 0x5 is 2**32 / 1000000000 (rounded up) */ +#define ndelay(n) (__builtin_constant_p(n) ? \ + ((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \ + __ndelay(n)) + +#endif /* _METAG_DELAY_H */ diff --git a/arch/metag/include/asm/mach/arch.h b/arch/metag/include/asm/mach/arch.h index 6845d80857e4..12c5664fea6e 100644 --- a/arch/metag/include/asm/mach/arch.h +++ b/arch/metag/include/asm/mach/arch.h @@ -16,10 +16,13 @@ #include <linux/stddef.h> +#include <asm/clock.h> + /** * struct machine_desc - Describes a board controlled by a Meta. * @name: Board/SoC name. * @dt_compat: Array of device tree 'compatible' strings. + * @clocks: Clock callbacks. * * @nr_irqs: Maximum number of IRQs. * If 0, defaults to NR_IRQS in asm-generic/irq.h. @@ -37,6 +40,7 @@ struct machine_desc { const char *name; const char **dt_compat; + struct meta_clock_desc *clocks; unsigned int nr_irqs; diff --git a/arch/metag/kernel/clock.c b/arch/metag/kernel/clock.c new file mode 100644 index 000000000000..defc84056f18 --- /dev/null +++ b/arch/metag/kernel/clock.c @@ -0,0 +1,53 @@ +/* + * arch/metag/kernel/clock.c + * + * Copyright (C) 2012 Imagination Technologies Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/delay.h> +#include <linux/io.h> + +#include <asm/param.h> +#include <asm/clock.h> + +struct meta_clock_desc _meta_clock; + +/* Default machine get_core_freq callback. */ +static unsigned long get_core_freq_default(void) +{ +#ifdef CONFIG_METAG_META21 + /* + * Meta 2 cores divide down the core clock for the Meta timers, so we + * can estimate the core clock from the divider. + */ + return (metag_in32(EXPAND_TIMER_DIV) + 1) * 1000000; +#else + /* + * On Meta 1 we don't know the core clock, but assuming the Meta timer + * is correct it can be estimated based on loops_per_jiffy. + */ + return (loops_per_jiffy * HZ * 5) >> 1; +#endif +} + +/** + * setup_meta_clocks() - Set up the Meta clock. + * @desc: Clock descriptor usually provided by machine description + * + * Ensures all callbacks are valid. + */ +void __init setup_meta_clocks(struct meta_clock_desc *desc) +{ + /* copy callbacks */ + if (desc) + _meta_clock = *desc; + + /* set fallback functions */ + if (!_meta_clock.get_core_freq) + _meta_clock.get_core_freq = get_core_freq_default; +} + diff --git a/arch/metag/kernel/time.c b/arch/metag/kernel/time.c new file mode 100644 index 000000000000..17dc10733b2f --- /dev/null +++ b/arch/metag/kernel/time.c @@ -0,0 +1,15 @@ +/* + * Copyright (C) 2005-2013 Imagination Technologies Ltd. + * + * This file contains the Meta-specific time handling details. + * + */ + +#include <linux/init.h> + +#include <clocksource/metag_generic.h> + +void __init time_init(void) +{ + metag_generic_timer_init(); +} diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 7fdcbd3f4da5..75bc7520ace5 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -58,3 +58,8 @@ config CLKSRC_ARM_GENERIC def_bool y if ARM64 help This option enables support for the ARM generic timer. + +config CLKSRC_METAG_GENERIC + def_bool y if METAG + help + This option enables support for the Meta per-thread timers. diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index f93453d01673..09dcd49b7e31 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -18,3 +18,4 @@ obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o obj-$(CONFIG_SUNXI_TIMER) += sunxi_timer.o obj-$(CONFIG_CLKSRC_ARM_GENERIC) += arm_generic.o +obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o diff --git a/drivers/clocksource/metag_generic.c b/drivers/clocksource/metag_generic.c new file mode 100644 index 000000000000..ade7513a11d1 --- /dev/null +++ b/drivers/clocksource/metag_generic.c @@ -0,0 +1,198 @@ +/* + * Copyright (C) 2005-2013 Imagination Technologies Ltd. + * + * 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. + * + * 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, see <http://www.gnu.org/licenses/>. + * + * + * Support for Meta per-thread timers. + * + * Meta hardware threads have 2 timers. The background timer (TXTIMER) is used + * as a free-running time base (hz clocksource), and the interrupt timer + * (TXTIMERI) is used for the timer interrupt (clock event). Both counters + * traditionally count at approximately 1MHz. + */ + +#include <clocksource/metag_generic.h> +#include <linux/cpu.h> +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/param.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/proc_fs.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> + +#include <asm/clock.h> +#include <asm/hwthread.h> +#include <asm/core_reg.h> +#include <asm/metag_mem.h> +#include <asm/tbx.h> + +#define HARDWARE_FREQ 1000000 /* 1MHz */ +#define HARDWARE_DIV 1 /* divide by 1 = 1MHz clock */ +#define HARDWARE_TO_NS_SHIFT 10 /* convert ticks to ns */ + +static unsigned int hwtimer_freq = HARDWARE_FREQ; +static DEFINE_PER_CPU(struct clock_event_device, local_clockevent); +static DEFINE_PER_CPU(char [11], local_clockevent_name); + +static int metag_timer_set_next_event(unsigned long delta, + struct clock_event_device *dev) +{ + __core_reg_set(TXTIMERI, -delta); + return 0; +} + +static void metag_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + switch (mode) { + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_RESUME: + break; + + case CLOCK_EVT_MODE_SHUTDOWN: + /* We should disable the IRQ here */ + break; + + case CLOCK_EVT_MODE_PERIODIC: + case CLOCK_EVT_MODE_UNUSED: + WARN_ON(1); + break; + }; +} + +static cycle_t metag_clocksource_read(struct clocksource *cs) +{ + return __core_reg_get(TXTIMER); +} + +static struct clocksource clocksource_metag = { + .name = "META", + .rating = 200, + .mask = CLOCKSOURCE_MASK(32), + .read = metag_clocksource_read, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static irqreturn_t metag_timer_interrupt(int irq, void *dummy) +{ + struct clock_event_device *evt = &__get_cpu_var(local_clockevent); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction metag_timer_irq = { + .name = "META core timer", + .handler = metag_timer_interrupt, + .flags = IRQF_TIMER | IRQF_IRQPOLL | IRQF_PERCPU, +}; + +unsigned long long sched_clock(void) +{ + unsigned long long ticks = __core_reg_get(TXTIMER); + return ticks << HARDWARE_TO_NS_SHIFT; +} + +static void __cpuinit arch_timer_setup(unsigned int cpu) +{ + unsigned int txdivtime; + struct clock_event_device *clk = &per_cpu(local_clockevent, cpu); + char *name = per_cpu(local_clockevent_name, cpu); + + txdivtime = __core_reg_get(TXDIVTIME); + + txdivtime &= ~TXDIVTIME_DIV_BITS; + txdivtime |= (HARDWARE_DIV & TXDIVTIME_DIV_BITS); + + __core_reg_set(TXDIVTIME, txdivtime); + + sprintf(name, "META %d", cpu); + clk->name = name; + clk->features = CLOCK_EVT_FEAT_ONESHOT, + + clk->rating = 200, + clk->shift = 12, + clk->irq = tbisig_map(TBID_SIGNUM_TRT), + clk->set_mode = metag_timer_set_mode, + clk->set_next_event = metag_timer_set_next_event, + + clk->mult = div_sc(hwtimer_freq, NSEC_PER_SEC, clk->shift); + clk->max_delta_ns = clockevent_delta2ns(0x7fffffff, clk); + clk->min_delta_ns = clockevent_delta2ns(0xf, clk); + clk->cpumask = cpumask_of(cpu); + + clockevents_register_device(clk); + + /* + * For all non-boot CPUs we need to synchronize our free + * running clock (TXTIMER) with the boot CPU's clock. + * + * While this won't be accurate, it should be close enough. + */ + if (cpu) { + unsigned int thread0 = cpu_2_hwthread_id[0]; + unsigned long val; + + val = core_reg_read(TXUCT_ID, TXTIMER_REGNUM, thread0); + __core_reg_set(TXTIMER, val); + } +} + +static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + int cpu = (long)hcpu; + + switch (action) { + case CPU_STARTING: + case CPU_STARTING_FROZEN: + arch_timer_setup(cpu); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block __cpuinitdata arch_timer_cpu_nb = { + .notifier_call = arch_timer_cpu_notify, +}; + +int __init metag_generic_timer_init(void) +{ + /* + * On Meta 2 SoCs, the actual frequency of the timer is based on the + * Meta core clock speed divided by an integer, so it is only + * approximately 1MHz. Calculating the real frequency here drastically + * reduces clock skew on these SoCs. + */ +#ifdef CONFIG_METAG_META21 + hwtimer_freq = get_coreclock() / (metag_in32(EXPAND_TIMER_DIV) + 1); +#endif + clocksource_register_hz(&clocksource_metag, hwtimer_freq); + + setup_irq(tbisig_map(TBID_SIGNUM_TRT), &metag_timer_irq); + + /* Configure timer on boot CPU */ + arch_timer_setup(smp_processor_id()); + + /* Hook cpu boot to configure other CPU's timers */ + register_cpu_notifier(&arch_timer_cpu_nb); + + return 0; +} diff --git a/include/clocksource/metag_generic.h b/include/clocksource/metag_generic.h new file mode 100644 index 000000000000..ac17e7d06cfb --- /dev/null +++ b/include/clocksource/metag_generic.h @@ -0,0 +1,21 @@ +/* + * Copyright (C) 2013 Imaginaton Technologies Ltd. + * + * 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. + * + * 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, see <http://www.gnu.org/licenses/>. + */ +#ifndef __CLKSOURCE_METAG_GENERIC_H +#define __CLKSOURCE_METAG_GENERIC_H + +extern int metag_generic_timer_init(void); + +#endif /* __CLKSOURCE_METAG_GENERIC_H */ |