From: Ley Foon Tan <lftan@altera.com>
To: <linux-arch@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-doc@vger.kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>, <lftan.linux@gmail.com>,
<cltang@codesourcery.com>
Subject: [PATCH 20/28] nios2: Time keeping
Date: Fri, 18 Apr 2014 20:27:03 +0800 [thread overview]
Message-ID: <1397824031-4892-17-git-send-email-lftan@altera.com> (raw)
In-Reply-To: <1397824031-4892-1-git-send-email-lftan@altera.com>
Add time keeping code for nios2.
Signed-off-by: Ley Foon Tan <lftan@altera.com>
---
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 <asm/param.h>
+
+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 <thomas@wytron.com.tw>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#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 <asm-generic/timex.h>
+
+#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 <tklauser@distanz.ch>
+ * 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/init.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/profile.h>
+#include <linux/clocksource.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+
+#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
next prev parent reply other threads:[~2014-04-18 12:42 UTC|newest]
Thread overview: 126+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-18 12:26 [PATCH 00/28] nios2 Linux kernel port Ley Foon Tan
2014-04-18 12:26 ` [PATCH 01/28] nios2: Build infrastructure Ley Foon Tan
2014-04-18 14:35 ` Sam Ravnborg
2014-04-21 3:03 ` Ley Foon Tan
2014-04-18 19:16 ` Paul Bolle
2014-04-21 5:02 ` Ley Foon Tan
2014-04-18 19:41 ` Paul Bolle
2014-04-21 3:26 ` Ley Foon Tan
2014-04-18 12:26 ` [PATCH 02/28] nios2: Assembly macros and definitions Ley Foon Tan
2014-04-18 12:26 ` [PATCH 04/28] nios2: Exception handling Ley Foon Tan
2014-04-22 10:57 ` Ezequiel Garcia
2014-04-22 11:08 ` Ley Foon Tan
2014-04-22 12:33 ` Arnd Bergmann
2014-04-23 2:47 ` Ley Foon Tan
2014-04-23 7:20 ` Geert Uytterhoeven
2014-04-23 12:23 ` Arnd Bergmann
2014-04-24 6:04 ` Ley Foon Tan
2014-04-18 12:26 ` [PATCH 06/28] nios2: Memory management Ley Foon Tan
2014-04-22 14:24 ` Ezequiel Garcia
2014-04-22 15:14 ` Tobias Klauser
2014-04-22 15:35 ` Ezequiel Garcia
2014-04-22 16:01 ` Chung-Lin Tang
2014-04-22 16:27 ` Ezequiel Garcia
2014-04-22 16:36 ` Chung-Lin Tang
2014-04-22 16:24 ` Sam Ravnborg
2014-04-23 2:53 ` LF.Tan
2014-04-23 7:24 ` Geert Uytterhoeven
2014-04-18 12:26 ` [PATCH 08/28] nios2: MMU Fault handling Ley Foon Tan
2014-04-22 14:30 ` Ezequiel Garcia
2014-04-24 6:42 ` Ley Foon Tan
2014-04-24 15:22 ` Ezequiel Garcia
2014-04-24 16:02 ` Ley Foon Tan
2014-04-24 16:18 ` Ezequiel Garcia
2014-04-24 7:18 ` Geert Uytterhoeven
2014-04-18 12:26 ` [PATCH 09/28] nios2: Page table management Ley Foon Tan
2014-04-19 16:05 ` Pavel Machek
2014-04-22 8:09 ` Ley Foon Tan
2014-04-18 12:26 ` [PATCH 10/28] nios2: Process management Ley Foon Tan
2014-04-18 12:26 ` [PATCH 11/28] nios2: Cache handling Ley Foon Tan
2014-04-18 12:26 ` [PATCH 12/28] nios2: TLB handling Ley Foon Tan
2014-04-18 12:26 ` [PATCH 13/28] nios2: Interrupt handling Ley Foon Tan
2014-04-18 12:26 ` [PATCH 15/28] nios2: ELF definitions Ley Foon Tan
2014-04-18 12:26 ` [PATCH 16/28] nios2: System calls handling Ley Foon Tan
2014-04-19 16:09 ` Pavel Machek
2014-04-21 17:32 ` Ley Foon Tan
2014-04-21 17:52 ` Richard Weinberger
2014-04-21 20:48 ` Pavel Machek
2014-04-22 8:24 ` Ley Foon Tan
2014-04-21 20:46 ` Pavel Machek
2014-04-19 20:12 ` Geert Uytterhoeven
2014-04-21 17:23 ` Ley Foon Tan
2014-04-22 12:30 ` Arnd Bergmann
2014-04-24 16:23 ` Ley Foon Tan
2014-04-18 12:27 ` [PATCH 17/28] nios2: Signal handling support Ley Foon Tan
2014-04-19 19:29 ` Richard Weinberger
2014-04-24 10:01 ` Ley Foon Tan
2014-04-24 10:07 ` Richard Weinberger
2014-04-24 10:13 ` Ley Foon Tan
2014-04-24 10:17 ` Richard Weinberger
2014-04-24 10:29 ` Ley Foon Tan
2014-04-24 10:39 ` Richard Weinberger
2014-04-24 10:46 ` Ley Foon Tan
2014-04-24 16:16 ` Richard Weinberger
2014-04-18 12:27 ` [PATCH 18/28] nios2: Library functions Ley Foon Tan
2014-04-18 12:27 ` [PATCH 19/28] nios2: Device tree support Ley Foon Tan
2014-04-22 13:42 ` Arnd Bergmann
2014-04-23 6:52 ` Ley Foon Tan
2014-04-23 7:35 ` Arnd Bergmann
2014-04-23 9:52 ` Ley Foon Tan
2014-04-24 16:05 ` Ezequiel Garcia
2014-04-18 12:27 ` Ley Foon Tan [this message]
2014-04-22 13:44 ` [PATCH 20/28] nios2: Time keeping Arnd Bergmann
2014-04-23 3:21 ` Ley Foon Tan
2014-04-18 12:27 ` [PATCH 21/28] nios2: Cpuinfo handling Ley Foon Tan
2014-04-18 12:27 ` [PATCH 22/28] nios2: Miscellaneous header files Ley Foon Tan
2014-04-18 12:27 ` [PATCH 23/28] nios2: Nios2 registers Ley Foon Tan
2014-04-22 12:39 ` Tobias Klauser
2014-04-23 7:10 ` Ley Foon Tan
2014-04-23 8:00 ` Tobias Klauser
2014-04-18 12:27 ` [PATCH 24/28] nios2: Module support Ley Foon Tan
2014-04-18 12:27 ` [PATCH 25/28] nios2: ptrace support Ley Foon Tan
2014-04-25 23:52 ` Pedro Alves
2014-04-28 6:03 ` Ley Foon Tan
2014-04-18 12:27 ` [PATCH 26/28] Add ELF machine define for Nios2 Ley Foon Tan
2014-04-18 12:27 ` [PATCH 27/28] MAINTAINERS: Add nios2 maintainer Ley Foon Tan
2014-04-18 12:27 ` [PATCH 28/28] Documentation: Add documentation for Nios2 architecture Ley Foon Tan
2014-04-22 12:28 ` Tobias Klauser
2014-04-23 7:48 ` Ley Foon Tan
2014-04-18 18:19 ` [PATCH 03/28] nios2: Kernel booting and initialization Ley Foon Tan
2014-04-18 18:19 ` [PATCH 05/28] nios2: Traps exception handling Ley Foon Tan
2014-04-22 14:28 ` Ezequiel Garcia
2014-04-23 10:07 ` Ley Foon Tan
2014-04-18 18:19 ` [PATCH 07/28] nios2: I/O Mapping Ley Foon Tan
2014-04-22 13:59 ` Arnd Bergmann
2014-04-24 6:02 ` Ley Foon Tan
2014-04-24 7:43 ` Arnd Bergmann
2014-04-24 15:51 ` Ley Foon Tan
2014-05-02 10:37 ` Ley Foon Tan
2014-05-02 12:22 ` Arnd Bergmann
2014-05-05 7:13 ` Ley Foon Tan
2014-04-18 18:19 ` [PATCH 14/28] nios2: DMA mapping API Ley Foon Tan
2014-04-22 13:52 ` Arnd Bergmann
2014-04-25 10:13 ` Ley Foon Tan
2014-04-25 10:33 ` Arnd Bergmann
2014-04-25 10:36 ` Ley Foon Tan
2014-04-18 20:48 ` [PATCH 00/28] nios2 Linux kernel port H. Peter Anvin
2014-04-19 15:30 ` Arnd Bergmann
2014-04-21 5:23 ` Ley Foon Tan
2014-04-21 5:31 ` H. Peter Anvin
2014-04-21 8:14 ` Chung-Lin Tang
2014-04-22 10:37 ` Ley Foon Tan
2014-04-22 10:56 ` Arnd Bergmann
2014-04-22 11:20 ` Ley Foon Tan
2014-04-22 14:48 ` Chung-Lin Tang
2014-04-23 17:59 ` Chung-Lin Tang
2014-04-23 18:15 ` Pinski, Andrew
2014-04-23 19:21 ` H. Peter Anvin
2014-04-24 6:26 ` Chung-Lin Tang
2014-04-24 8:55 ` Chung-Lin Tang
2014-04-24 15:28 ` Catalin Marinas
2014-04-24 18:37 ` Chung-Lin Tang
2014-04-24 18:42 ` Pinski, Andrew
2014-04-25 6:06 ` Chung-Lin Tang
2014-04-25 8:37 ` Pinski, Andrew
2014-04-25 13:19 ` Chung-Lin Tang
2014-04-25 8:49 ` Geert Uytterhoeven
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