Add time keeping code for nios2. Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx> --- arch/nios2/include/asm/delay.h | 21 +++ arch/nios2/include/asm/timex.h | 24 ++++ arch/nios2/kernel/time.c | 310 +++++++++++++++++++++++++++++++++++++++++ arch/nios2/lib/delay.c | 52 +++++++ 4 files changed, 407 insertions(+) create mode 100644 arch/nios2/include/asm/delay.h create mode 100644 arch/nios2/include/asm/timex.h create mode 100644 arch/nios2/kernel/time.c create mode 100644 arch/nios2/lib/delay.c diff --git a/arch/nios2/include/asm/delay.h b/arch/nios2/include/asm/delay.h new file mode 100644 index 0000000..098e49b --- /dev/null +++ b/arch/nios2/include/asm/delay.h @@ -0,0 +1,21 @@ +/* + * Copyright (C) 2014 Altera Corporation + * Copyright (C) 2004 Microtronix Datacom Ltd + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#ifndef _ASM_NIOS2_DELAY_H +#define _ASM_NIOS2_DELAY_H + +#include <asm-generic/delay.h> + +/* Undefined functions to get compile-time errors */ +extern void __bad_udelay(void); +extern void __bad_ndelay(void); + +extern unsigned long loops_per_jiffy; + +#endif /* _ASM_NIOS2_DELAY_H */ diff --git a/arch/nios2/include/asm/timex.h b/arch/nios2/include/asm/timex.h new file mode 100644 index 0000000..2f2abb2 --- /dev/null +++ b/arch/nios2/include/asm/timex.h @@ -0,0 +1,24 @@ +/* Copyright Altera Corporation (C) 2014. All rights reserved. + * + * 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 _ASM_NIOS2_TIMEX_H +#define _ASM_NIOS2_TIMEX_H + +typedef unsigned long cycles_t; + +extern cycles_t get_cycles(void); + +#endif diff --git a/arch/nios2/kernel/time.c b/arch/nios2/kernel/time.c new file mode 100644 index 0000000..d90ca1b --- /dev/null +++ b/arch/nios2/kernel/time.c @@ -0,0 +1,310 @@ +/* + * Copyright (C) 2013-2014 Altera Corporation + * Copyright (C) 2010 Tobias Klauser <tklauser@xxxxxxxxxx> + * Copyright (C) 2004 Microtronix Datacom Ltd. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/interrupt.h> +#include <linux/clockchips.h> +#include <linux/clocksource.h> +#include <linux/delay.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/io.h> +#include <linux/slab.h> + +#define ALTERA_TIMER_STATUS_REG 0 +#define ALTERA_TIMER_CONTROL_REG 4 +#define ALTERA_TIMER_PERIODL_REG 8 +#define ALTERA_TIMER_PERIODH_REG 12 +#define ALTERA_TIMER_SNAPL_REG 16 +#define ALTERA_TIMER_SNAPH_REG 20 + +#define ALTERA_TIMER_CONTROL_ITO_MSK (0x1) +#define ALTERA_TIMER_CONTROL_CONT_MSK (0x2) +#define ALTERA_TIMER_CONTROL_START_MSK (0x4) +#define ALTERA_TIMER_CONTROL_STOP_MSK (0x8) + +struct nios2_timer { + void __iomem *base; + unsigned long freq; + int irq; +}; + +struct nios2_clockevent_dev { + struct nios2_timer timer; + struct clock_event_device ced; +}; + +struct nios2_clocksource { + struct nios2_timer timer; + struct clocksource cs; +}; + +static inline struct nios2_clockevent_dev * + to_nios2_clkevent(struct clock_event_device *evt) +{ + return container_of(evt, struct nios2_clockevent_dev, ced); +} + +static inline struct nios2_clocksource * + to_nios2_clksource(struct clocksource *cs) +{ + return container_of(cs, struct nios2_clocksource, cs); +} + +static u16 timer_readw(struct nios2_timer *timer, u32 offs) +{ + return readw(timer->base + offs); +} + +static void timer_writew(struct nios2_timer *timer, u16 val, u32 offs) +{ + writew(val, timer->base + offs); +} + +static inline unsigned long read_timersnapshot(struct nios2_timer *timer) +{ + unsigned long count; + + timer_writew(timer, 0, ALTERA_TIMER_SNAPL_REG); + count = timer_readw(timer, ALTERA_TIMER_SNAPH_REG) << 16 | + timer_readw(timer, ALTERA_TIMER_SNAPL_REG); + + return count; +} + +static cycle_t nios2_timer_read(struct clocksource *cs) +{ + struct nios2_clocksource *nios2_cs = to_nios2_clksource(cs); + unsigned long flags; + u32 count; + + local_irq_save(flags); + count = read_timersnapshot(&nios2_cs->timer); + local_irq_restore(flags); + + /* Counter is counting down */ + return ~count; +} + +static struct nios2_clocksource nios2_cs = { + .cs = { + .name = "nios2-clksrc", + .rating = 250, + .read = nios2_timer_read, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + }, +}; + +cycles_t get_cycles(void) +{ + return nios2_timer_read(&nios2_cs.cs); +} + +static void nios2_timer_start(struct nios2_timer *timer) +{ + u16 ctrl; + + ctrl = timer_readw(timer, ALTERA_TIMER_CONTROL_REG); + ctrl |= ALTERA_TIMER_CONTROL_START_MSK; + timer_writew(timer, ctrl, ALTERA_TIMER_CONTROL_REG); +} + +static void nios2_timer_stop(struct nios2_timer *timer) +{ + u16 ctrl; + + ctrl = timer_readw(timer, ALTERA_TIMER_CONTROL_REG); + ctrl |= ALTERA_TIMER_CONTROL_STOP_MSK; + timer_writew(timer, ctrl, ALTERA_TIMER_CONTROL_REG); +} + +static void nios2_timer_config(struct nios2_timer *timer, unsigned long period, + enum clock_event_mode mode) +{ + u16 ctrl; + + /* The timer's actual period is one cycle greater than the value + * stored in the period register. */ + period--; + + ctrl = timer_readw(timer, ALTERA_TIMER_CONTROL_REG); + /* stop counter */ + timer_writew(timer, ctrl | ALTERA_TIMER_CONTROL_STOP_MSK, + ALTERA_TIMER_CONTROL_REG); + + /* write new count */ + timer_writew(timer, period, ALTERA_TIMER_PERIODL_REG); + timer_writew(timer, period >> 16, ALTERA_TIMER_PERIODH_REG); + + ctrl |= ALTERA_TIMER_CONTROL_START_MSK | ALTERA_TIMER_CONTROL_ITO_MSK; + if (mode == CLOCK_EVT_MODE_PERIODIC) + ctrl |= ALTERA_TIMER_CONTROL_CONT_MSK; + else + ctrl &= ~ALTERA_TIMER_CONTROL_CONT_MSK; + timer_writew(timer, ctrl, ALTERA_TIMER_CONTROL_REG); +} + +static int nios2_timer_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + struct nios2_clockevent_dev *nios2_ced = to_nios2_clkevent(evt); + + nios2_timer_config(&nios2_ced->timer, delta, evt->mode); + + return 0; +} + +static void nios2_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long period; + struct nios2_clockevent_dev *nios2_ced = to_nios2_clkevent(evt); + struct nios2_timer *timer = &nios2_ced->timer; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + period = DIV_ROUND_UP(timer->freq, HZ); + nios2_timer_config(timer, period, CLOCK_EVT_MODE_PERIODIC); + break; + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + nios2_timer_stop(timer); + break; + case CLOCK_EVT_MODE_RESUME: + nios2_timer_start(timer); + break; + } +} + +irqreturn_t timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = (struct clock_event_device *) dev_id; + struct nios2_clockevent_dev *nios2_ced = to_nios2_clkevent(evt); + + /* Clear the interrupt condition */ + timer_writew(&nios2_ced->timer, 0, ALTERA_TIMER_STATUS_REG); + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static void __init nios2_timer_get_base_and_freq(struct device_node *np, + void __iomem **base, u32 *freq) +{ + *base = of_iomap(np, 0); + if (!*base) + panic("Unable to map reg for %s\n", np->name); + + if (of_property_read_u32(np, "clock-frequency", freq)) + panic("Unable to get %s clock frequency\n", np->name); +} + +static struct nios2_clockevent_dev nios2_ce = { + .ced = { + .name = "nios2-clkevent", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .rating = 250, + .shift = 32, + .set_next_event = nios2_timer_set_next_event, + .set_mode = nios2_timer_set_mode, + }, +}; + +static __init void nios2_clockevent_init(struct device_node *timer) +{ + void __iomem *iobase; + u32 freq; + int irq; + + nios2_timer_get_base_and_freq(timer, &iobase, &freq); + + irq = irq_of_parse_and_map(timer, 0); + if (irq < 0) + panic("Unable to parse timer irq\n"); + + nios2_ce.timer.base = iobase; + nios2_ce.timer.irq = irq; + nios2_ce.timer.freq = freq; + + nios2_ce.ced.cpumask = cpumask_of(0); + nios2_ce.ced.irq = irq; + + nios2_timer_stop(&nios2_ce.timer); + /* clear pending interrupt */ + timer_writew(&nios2_ce.timer, 0, ALTERA_TIMER_STATUS_REG); + + if (request_irq(irq, timer_interrupt, IRQF_TIMER, timer->name, + &nios2_ce.ced)) + panic("Unable to setup timer irq\n"); + + clockevents_config_and_register(&nios2_ce.ced, freq, 1, ULONG_MAX); +} + +static __init void nios2_clocksource_init(struct device_node *timer) +{ + unsigned int ctrl; + void __iomem *iobase; + u32 freq; + + nios2_timer_get_base_and_freq(timer, &iobase, &freq); + + nios2_cs.timer.base = iobase; + nios2_cs.timer.freq = freq; + + clocksource_register_hz(&nios2_cs.cs, freq); + + timer_writew(&nios2_cs.timer, USHRT_MAX, ALTERA_TIMER_PERIODL_REG); + timer_writew(&nios2_cs.timer, USHRT_MAX, ALTERA_TIMER_PERIODH_REG); + + /* interrupt disable + continuous + start */ + ctrl = ALTERA_TIMER_CONTROL_CONT_MSK | ALTERA_TIMER_CONTROL_START_MSK; + timer_writew(&nios2_cs.timer, ctrl, ALTERA_TIMER_CONTROL_REG); + + /* Calibrate the delay loop directly */ + lpj_fine = freq / HZ; +} + +/* + * The first timer instance will use as a clockevent. If there are two or + * more instances, the second one gets used as clocksource and all + * others are unused. +*/ +static void __init nios2_time_init(struct device_node *timer) +{ + static int num_called; + + switch (num_called) { + case 0: + nios2_clockevent_init(timer); + break; + case 1: + nios2_clocksource_init(timer); + break; + default: + break; + } + + num_called++; +} + +void read_persistent_clock(struct timespec *ts) +{ + ts->tv_sec = mktime(2007, 1, 1, 0, 0, 0); + ts->tv_nsec = 0; +} + +void __init time_init(void) +{ + clocksource_of_init(); +} + +CLOCKSOURCE_OF_DECLARE(nios2_timer, "altr,timer-1.0", nios2_time_init); diff --git a/arch/nios2/lib/delay.c b/arch/nios2/lib/delay.c new file mode 100644 index 0000000..088119c --- /dev/null +++ b/arch/nios2/lib/delay.c @@ -0,0 +1,52 @@ +/* Copyright Altera Corporation (C) 2014. All rights reserved. + * + * 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/>. + * + */ + +#include <linux/module.h> +#include <asm/delay.h> +#include <asm/param.h> +#include <asm/processor.h> +#include <asm/timex.h> + +void __delay(unsigned long cycles) +{ + cycles_t start = get_cycles(); + + while ((get_cycles() - start) < cycles) + cpu_relax(); +} +EXPORT_SYMBOL(__delay); + +void __const_udelay(unsigned long xloops) +{ + u64 loops; + + loops = (u64)xloops * loops_per_jiffy * HZ; + + __delay(loops >> 32); +} +EXPORT_SYMBOL(__const_udelay); + +void __udelay(unsigned long usecs) +{ + __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */ +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long nsecs) +{ + __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */ +} +EXPORT_SYMBOL(__ndelay); -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
