Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752770AbaDRMmj (ORCPT ); Fri, 18 Apr 2014 08:42:39 -0400 Received: from mail-bn1blp0187.outbound.protection.outlook.com ([207.46.163.187]:3012 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751185AbaDRMmc (ORCPT ); Fri, 18 Apr 2014 08:42:32 -0400 X-Greylist: delayed 894 seconds by postgrey-1.27 at vger.kernel.org; Fri, 18 Apr 2014 08:42:32 EDT From: Ley Foon Tan To: , , CC: Ley Foon Tan , , Subject: [PATCH 20/28] nios2: Time keeping Date: Fri, 18 Apr 2014 20:27:03 +0800 Message-ID: <1397824031-4892-17-git-send-email-lftan@altera.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1397824031-4892-1-git-send-email-lftan@altera.com> References: <1397824031-4892-1-git-send-email-lftan@altera.com> MIME-Version: 1.0 Content-Type: text/plain X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:66.35.236.232;CTRY:US;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10019001)(6009001)(458001)(199002)(189002)(22564002)(76176999)(99396002)(6806004)(50986999)(80022001)(87286001)(93916002)(88136002)(86362001)(575784001)(50466002)(19580405001)(62966002)(2201001)(92566001)(92726001)(77982001)(2009001)(47776003)(20776003)(80976001)(44976005)(48376002)(83322001)(19580395003)(84676001)(81542001)(97736001)(76482001)(81342001)(77156001)(83072002)(85852003)(42186004)(36756003)(4396001)(87936001)(89996001)(50226001)(46102001)(16796002)(74502001)(31966008)(74662001);DIR:OUT;SFP:1102;SCL:1;SRVR:BL2FFO11HUB029;H:SJ-ITEXEDGE02.altera.priv.altera.com;FPR:CC9ED165.2FEADFC5.E0F046BA.6EF79230.206E9;MLV:sfv;PTR:InfoDomainNonexistent;A:1;MX:1;LANG:en; X-OriginatorOrg: altera.onmicrosoft.com X-Forefront-PRVS: 018577E36E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add time keeping code for nios2. Signed-off-by: Ley Foon Tan --- arch/nios2/include/asm/delay.h | 92 +++++++++++++++++++++++++ arch/nios2/include/asm/timex.h | 27 ++++++++ arch/nios2/kernel/time.c | 150 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 269 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 diff --git a/arch/nios2/include/asm/delay.h b/arch/nios2/include/asm/delay.h new file mode 100644 index 0000000..8070a09 --- /dev/null +++ b/arch/nios2/include/asm/delay.h @@ -0,0 +1,92 @@ +/* + * 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 + +static inline void __delay(unsigned long loops) +{ + int dummy; + + __asm__ __volatile__( + "1:\n\t" + " beq %0,zero,2f\n\t" + " addi %0, %0, -1\n\t" + " br 1b\n\t" + "2:\n\t" + : "=r" (dummy) /* Need output for optimizer */ + : "0" (loops)); /* %0 Input */ +} + +/* + * Note that 19 * 226 == 4294 ==~ 2^32 / 10^6, so + * loops = (4294 * usecs * loops_per_jiffy * HZ) / 2^32. + * + * The mul instruction gives us loops = (a * b) / 2^32. + * We choose a = usecs * 19 * HZ and b = loops_per_jiffy * 226 + * because this lets us support a wide range of HZ and + * loops_per_jiffy values without either a or b overflowing 2^32. + * Thus we need usecs * HZ <= (2^32 - 1) / 19 = 226050910 and + * loops_per_jiffy <= (2^32 - 1) / 226 = 19004280 + * (which corresponds to ~3800 bogomips at HZ = 100). + * -- paulus + */ +#define __MAX_UDELAY (226050910UL/HZ) /* maximum udelay argument */ +#define __MAX_NDELAY (4294967295UL/HZ) /* maximum ndelay argument */ + +extern unsigned long loops_per_jiffy; + +static inline void __udelay(unsigned int x) +{ + unsigned int loops; + + /* + * Note, if this is compiled with -mhw-mulx it will produce a "mulxuu" + * (at least in toolchain 145) so there is no need for inline + * assembly here anymore, which might in turn be emulated if unsupported + * by the design. + */ + loops = (unsigned int)((((unsigned long long)(x) * + (unsigned long long)(loops_per_jiffy * 226))) >> 32); + +/* + __asm__("mulxuu %0,%1,%2" : "=r" (loops) : + "r" (x), "r" (loops_per_jiffy * 226)); +*/ + __delay(loops); +} + +static inline void __ndelay(unsigned int x) +{ + unsigned int loops; + + /* see comment in __udelay */ + loops = (unsigned int)((((unsigned long long)(x) * + (unsigned long long)(loops_per_jiffy * 5))) >> 32); + +/* + __asm__("mulxuu %0,%1,%2" : "=r" (loops) : + "r" (x), "r" (loops_per_jiffy * 5)); +*/ + __delay(loops); +} + +extern void __bad_udelay(void); /* deliberately undefined */ +extern void __bad_ndelay(void); /* deliberately undefined */ + +#define udelay(n) (__builtin_constant_p(n) ? \ + ((n) > __MAX_UDELAY ? __bad_udelay() : __udelay((n) * (19 * HZ))) : \ + __udelay((n) * (19 * HZ))) + +#define ndelay(n) (__builtin_constant_p(n) ? \ + ((n) > __MAX_NDELAY ? __bad_ndelay() : __ndelay((n) * HZ)) : \ + __ndelay((n) * HZ)) + +#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..524b47d79d3dad53b98713f31517e28ac0c99d98 --- /dev/null +++ b/arch/nios2/include/asm/timex.h @@ -0,0 +1,27 @@ +/* + * Copyright (C) 2010 Thomas Chou + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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 . + * + */ + +#ifndef _ASM_NIOS2_TIMEX_H +#define _ASM_NIOS2_TIMEX_H + +/* Supply dummy tick-rate. Real value will be read from devicetree */ +#define CLOCK_TICK_RATE (HZ * 100000UL) + +#include + +#endif diff --git a/arch/nios2/kernel/time.c b/arch/nios2/kernel/time.c new file mode 100644 index 0000000..0677ebaa1dffd8213f52a704c6a8366d34c05ca2 --- /dev/null +++ b/arch/nios2/kernel/time.c @@ -0,0 +1,150 @@ +/* + * Copyright (C) 2013 Altera Corporation + * Copyright (C) 2010 Tobias Klauser + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TICK_SIZE (tick_nsec / 1000) +#define NIOS2_TIMER_PERIOD (timer_freq / HZ) + +#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) + +static u32 nios2_timer_count; +static void __iomem *timer_membase; +static u32 timer_freq; + +static inline unsigned long read_timersnapshot(void) +{ + unsigned long count; + + outw(0, timer_membase + ALTERA_TIMER_SNAPL_REG); + count = + inw(timer_membase + ALTERA_TIMER_SNAPH_REG) << 16 | + inw(timer_membase + ALTERA_TIMER_SNAPL_REG); + + return count; +} + +static inline void write_timerperiod(unsigned long period) +{ + outw(period, timer_membase + ALTERA_TIMER_PERIODL_REG); + outw(period >> 16, timer_membase + ALTERA_TIMER_PERIODH_REG); +} + +/* + * timer_interrupt() needs to keep up the real-time clock, + * as well as call the "xtime_update()" routine every clocktick + */ +irqreturn_t timer_interrupt(int irq, void *dummy) +{ + /* Clear the interrupt condition */ + outw(0, timer_membase + ALTERA_TIMER_STATUS_REG); + nios2_timer_count += NIOS2_TIMER_PERIOD; + + profile_tick(CPU_PROFILING); + + xtime_update(1); + + update_process_times(user_mode(get_irq_regs())); + + return IRQ_HANDLED; +} + +static cycle_t nios2_timer_read(struct clocksource *cs) +{ + unsigned long flags; + u32 cycles; + u32 tcn; + + local_irq_save(flags); + tcn = NIOS2_TIMER_PERIOD - 1 - read_timersnapshot(); + cycles = nios2_timer_count; + local_irq_restore(flags); + + return cycles + tcn; +} + +static struct clocksource nios2_timer = { + .name = "timer", + .rating = 250, + .read = nios2_timer_read, + .shift = 20, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static struct irqaction nios2_timer_irq = { + .name = "timer", + .flags = IRQF_TIMER, + .handler = timer_interrupt, +}; + +static void __init nios2_time_init(struct device_node *timer) +{ + int irq; + unsigned int ctrl; + + timer_membase = of_iomap(timer, 0); + if (!timer_membase) + panic("Unable to map timer resource\n"); + + if (of_property_read_u32(timer, "clock-frequency", &timer_freq)) + panic("Unable to get timer clock frequency\n"); + + irq = irq_of_parse_and_map(timer, 0); + if (irq < 0) + panic("Unable to parse timer irq\n"); + + if (setup_irq(irq, &nios2_timer_irq)) + panic("Unable to setup timer irq\n"); + + write_timerperiod(NIOS2_TIMER_PERIOD - 1); + + /* clocksource initialize */ + nios2_timer.mult = clocksource_hz2mult(timer_freq, nios2_timer.shift); + clocksource_register(&nios2_timer); + + /* interrupt enable + continuous + start */ + ctrl = ALTERA_TIMER_CONTROL_ITO_MSK | ALTERA_TIMER_CONTROL_CONT_MSK | + ALTERA_TIMER_CONTROL_START_MSK; + outw(ctrl, timer_membase + ALTERA_TIMER_CONTROL_REG); +} + +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); -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/