Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: Linus Walleij <linus.walleij@linaro.org>
To: linux-arm-kernel@lists.infradead.org,
	Imre Kaloz <kaloz@openwrt.org>,
	Krzysztof Halasa <khalasa@piap.pl>
Cc: Arnd Bergmann <arnd@arndb.de>, Tim Harvey <tharvey@gateworks.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Olof Johansson <olof@lixom.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Linus Walleij <linus.walleij@linaro.org>
Subject: [PATCH 07/17 v1] clocksource/drivers/ixp4xx: Add driver
Date: Sun,  3 Feb 2019 22:41:55 +0100
Message-ID: <20190203214205.13594-8-linus.walleij@linaro.org> (raw)
In-Reply-To: <20190203214205.13594-1-linus.walleij@linaro.org>

This adds a new slightly rewritten timer driver for the
Intel IXP4xx clocksource, clockevent and delay timer.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
Clocksource/timer maintainers: I am requesting an ACK for
this once you're happy with the driver, as I intend to
merge all of this IXP4xx rework through ARM SoC.
---
 MAINTAINERS                                |   2 +
 drivers/clocksource/Kconfig                |   7 +
 drivers/clocksource/Makefile               |   1 +
 drivers/clocksource/timer-ixp4xx.c         | 249 +++++++++++++++++++++
 include/linux/platform_data/timer-ixp4xx.h |  11 +
 5 files changed, 270 insertions(+)
 create mode 100644 drivers/clocksource/timer-ixp4xx.c
 create mode 100644 include/linux/platform_data/timer-ixp4xx.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 6c161bd82238..a2fb67b75026 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1651,9 +1651,11 @@ M:	Krzysztof Halasa <khalasa@piap.pl>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	arch/arm/mach-ixp4xx/
+F:	drivers/clocksource/timer-ixp4xx.c
 F:	drivers/gpio/gpio-ixp4xx.c
 F:	drivers/irqchip/irq-ixp4xx.c
 F:	include/linux/irqchip/irq-ixp4xx.h
+F:	include/linux/platform_data/timer-ixp4xx.h
 
 ARM/INTEL RESEARCH IMOTE/STARGATE 2 MACHINE SUPPORT
 M:	Jonathan Cameron <jic23@cam.ac.uk>
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index a9e26f6a81a1..d290d6c6576d 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -69,6 +69,13 @@ config FTTMR010_TIMER
 	  Enables support for the Faraday Technology timer block
 	  FTTMR010.
 
+config IXP4XX_TIMER
+	bool "Intel XScale IXP4xx timer driver" if COMPILE_TEST
+	depends on HAS_IOMEM
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Intel XScale IXP4xx SoC timer.
+
 config ROCKCHIP_TIMER
 	bool "Rockchip timer driver" if COMPILE_TEST
 	depends on ARM || ARM64
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index cdd210ff89ea..18158257ebb3 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_OMAP_DM_TIMER)	+= timer-ti-dm.o
 obj-$(CONFIG_DW_APB_TIMER)	+= dw_apb_timer.o
 obj-$(CONFIG_DW_APB_TIMER_OF)	+= dw_apb_timer_of.o
 obj-$(CONFIG_FTTMR010_TIMER)	+= timer-fttmr010.o
+obj-$(CONFIG_IXP4XX_TIMER)	+= timer-ixp4xx.o
 obj-$(CONFIG_ROCKCHIP_TIMER)      += timer-rockchip.o
 obj-$(CONFIG_CLKSRC_NOMADIK_MTU)	+= nomadik-mtu.o
 obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
diff --git a/drivers/clocksource/timer-ixp4xx.c b/drivers/clocksource/timer-ixp4xx.c
new file mode 100644
index 000000000000..fa78f80792db
--- /dev/null
+++ b/drivers/clocksource/timer-ixp4xx.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IXP4 timer driver
+ * Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Based on arch/arm/mach-ixp4xx/common.c
+ * Copyright 2002 (C) Intel Corporation
+ * Copyright 2003-2004 (C) MontaVista, Software, Inc.
+ * Copyright (C) Deepak Saxena <dsaxena@plexity.net>
+ */
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+/* Goes away with OF conversion */
+#include <linux/platform_data/timer-ixp4xx.h>
+
+/*
+ * Constants to make it easy to access Timer Control/Status registers
+ */
+#define IXP4XX_OSTS_OFFSET	0x00  /* Continuous Timestamp */
+#define IXP4XX_OST1_OFFSET	0x04  /* Timer 1 Timestamp */
+#define IXP4XX_OSRT1_OFFSET	0x08  /* Timer 1 Reload */
+#define IXP4XX_OST2_OFFSET	0x0C  /* Timer 2 Timestamp */
+#define IXP4XX_OSRT2_OFFSET	0x10  /* Timer 2 Reload */
+#define IXP4XX_OSWT_OFFSET	0x14  /* Watchdog Timer */
+#define IXP4XX_OSWE_OFFSET	0x18  /* Watchdog Enable */
+#define IXP4XX_OSWK_OFFSET	0x1C  /* Watchdog Key */
+#define IXP4XX_OSST_OFFSET	0x20  /* Timer Status */
+
+/*
+ * Timer register values and bit definitions
+ */
+#define IXP4XX_OST_ENABLE		0x00000001
+#define IXP4XX_OST_ONE_SHOT		0x00000002
+/* Low order bits of reload value ignored */
+#define IXP4XX_OST_RELOAD_MASK		0x00000003
+#define IXP4XX_OST_DISABLED		0x00000000
+#define IXP4XX_OSST_TIMER_1_PEND	0x00000001
+#define IXP4XX_OSST_TIMER_2_PEND	0x00000002
+#define IXP4XX_OSST_TIMER_TS_PEND	0x00000004
+#define IXP4XX_OSST_TIMER_WDOG_PEND	0x00000008
+#define IXP4XX_OSST_TIMER_WARM_RESET	0x00000010
+
+#define	IXP4XX_WDT_KEY			0x0000482E
+#define	IXP4XX_WDT_RESET_ENABLE		0x00000001
+#define	IXP4XX_WDT_IRQ_ENABLE		0x00000002
+#define	IXP4XX_WDT_COUNT_ENABLE		0x00000004
+
+struct ixp4xx_timer {
+	void __iomem *base;
+	unsigned int tick_rate;
+	u32 latch;
+	struct clock_event_device clkevt;
+#ifdef CONFIG_ARM
+	struct delay_timer delay_timer;
+#endif
+};
+
+/*
+ * A local singleton used by sched_clock and delay timer reads, which are
+ * fast and stateless
+ */
+static struct ixp4xx_timer *local_ixp4xx_timer;
+
+static inline struct ixp4xx_timer *
+to_ixp4xx_timer(struct clock_event_device *evt)
+{
+	return container_of(evt, struct ixp4xx_timer, clkevt);
+}
+
+static u64 notrace ixp4xx_read_sched_clock(void)
+{
+	return __raw_readl(local_ixp4xx_timer->base + IXP4XX_OSTS_OFFSET);
+}
+
+static u64 ixp4xx_clocksource_read(struct clocksource *c)
+{
+	return __raw_readl(local_ixp4xx_timer->base + IXP4XX_OSTS_OFFSET);
+}
+
+static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id)
+{
+	struct ixp4xx_timer *tmr = dev_id;
+	struct clock_event_device *evt = &tmr->clkevt;
+
+	/* Clear Pending Interrupt */
+	__raw_writel(IXP4XX_OSST_TIMER_1_PEND,
+		     tmr->base + IXP4XX_OSST_OFFSET);
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static int ixp4xx_set_next_event(unsigned long cycles,
+				 struct clock_event_device *evt)
+{
+	struct ixp4xx_timer *tmr = to_ixp4xx_timer(evt);
+	u32 val;
+
+	val = __raw_readl(tmr->base + IXP4XX_OSRT1_OFFSET);
+	/* Keep enable/oneshot bits */
+	val &= IXP4XX_OST_RELOAD_MASK;
+	__raw_writel((cycles & ~IXP4XX_OST_RELOAD_MASK) | val,
+		     tmr->base + IXP4XX_OSRT1_OFFSET);
+
+	return 0;
+}
+
+static int ixp4xx_shutdown(struct clock_event_device *evt)
+{
+	struct ixp4xx_timer *tmr = to_ixp4xx_timer(evt);
+	u32 val;
+
+	val = __raw_readl(tmr->base + IXP4XX_OSRT1_OFFSET);
+	val &= ~IXP4XX_OST_ENABLE;
+	__raw_writel(val, tmr->base + IXP4XX_OSRT1_OFFSET);
+
+	return 0;
+}
+
+static int ixp4xx_set_oneshot(struct clock_event_device *evt)
+{
+	struct ixp4xx_timer *tmr = to_ixp4xx_timer(evt);
+
+	__raw_writel(IXP4XX_OST_ENABLE | IXP4XX_OST_ONE_SHOT,
+		     tmr->base + IXP4XX_OSRT1_OFFSET);
+
+	return 0;
+}
+
+static int ixp4xx_set_periodic(struct clock_event_device *evt)
+{
+	struct ixp4xx_timer *tmr = to_ixp4xx_timer(evt);
+	u32 val;
+
+	val = tmr->latch & ~IXP4XX_OST_RELOAD_MASK;
+	val |= IXP4XX_OST_ENABLE;
+	__raw_writel(val, tmr->base + IXP4XX_OSRT1_OFFSET);
+
+	return 0;
+}
+
+static int ixp4xx_resume(struct clock_event_device *evt)
+{
+	struct ixp4xx_timer *tmr = to_ixp4xx_timer(evt);
+	u32 val;
+
+	val = __raw_readl(tmr->base + IXP4XX_OSRT1_OFFSET);
+	val |= IXP4XX_OST_ENABLE;
+	__raw_writel(val, tmr->base + IXP4XX_OSRT1_OFFSET);
+
+	return 0;
+}
+
+/*
+ * IXP4xx timer tick
+ * We use OS timer1 on the CPU for the timer tick and the timestamp
+ * counter as a source of real clock ticks to account for missed jiffies.
+ */
+static __init int ixp4xx_timer_register(void __iomem *base,
+					int timer_irq,
+					unsigned int timer_freq)
+{
+	struct ixp4xx_timer *tmr;
+	int ret;
+
+	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
+	if (!tmr)
+		return -ENOMEM;
+	tmr->base = base;
+	tmr->tick_rate = timer_freq;
+
+	/*
+	 * The timer register doesn't allow to specify the two least
+	 * significant bits of the timeout value and assumes them being zero.
+	 * So make sure the latch is the best value with the two least
+	 * significant bits unset.
+	 */
+	tmr->latch = DIV_ROUND_CLOSEST(timer_freq,
+				       (IXP4XX_OST_RELOAD_MASK + 1) * HZ)
+		* (IXP4XX_OST_RELOAD_MASK + 1);
+
+	local_ixp4xx_timer = tmr;
+
+	/* Reset/disable counter */
+	__raw_writel(0, tmr->base + IXP4XX_OSRT1_OFFSET);
+
+	/* Clear any pending interrupt on timer 1 */
+	__raw_writel(IXP4XX_OSST_TIMER_1_PEND,
+		     tmr->base + IXP4XX_OSST_OFFSET);
+
+	/* Reset time-stamp counter */
+	__raw_writel(0, tmr->base + IXP4XX_OSTS_OFFSET);
+
+	clocksource_mmio_init(NULL, "OSTS", timer_freq, 200, 32,
+			      ixp4xx_clocksource_read);
+
+	tmr->clkevt.name = "ixp4xx timer1";
+	tmr->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+	tmr->clkevt.rating = 200;
+	tmr->clkevt.set_state_shutdown = ixp4xx_shutdown;
+	tmr->clkevt.set_state_periodic = ixp4xx_set_periodic;
+	tmr->clkevt.set_state_oneshot = ixp4xx_set_oneshot;
+	tmr->clkevt.tick_resume = ixp4xx_resume;
+	tmr->clkevt.set_next_event = ixp4xx_set_next_event;
+	tmr->clkevt.cpumask = cpumask_of(0);
+	tmr->clkevt.irq = timer_irq;
+	ret = request_irq(timer_irq, ixp4xx_timer_interrupt,
+			  IRQF_TIMER, "IXP4XX-TIMER1", tmr);
+	if (ret) {
+		pr_crit("no timer IRQ\n");
+		return -ENODEV;
+	}
+	clockevents_config_and_register(&tmr->clkevt, timer_freq,
+					0xf, 0xfffffffe);
+
+#ifdef CONFIG_ARM
+	sched_clock_register(ixp4xx_read_sched_clock, 32, timer_freq);
+#endif
+
+	return 0;
+}
+
+/**
+ * ixp4xx_timer_setup() - Timer setup function to be called from boardfiles
+ * @timerbase: physical base of timer block
+ * @timer_irq: Linux IRQ number for the timer
+ * @timer_freq: Fixed frequency of the timer
+ */
+void __init ixp4xx_timer_setup(resource_size_t timerbase,
+			       int timer_irq,
+			       unsigned int timer_freq)
+{
+	void __iomem *base;
+
+	base = ioremap(timerbase, 0x100);
+	if (!base) {
+		pr_crit("IXP4xx: can't remap timer\n");
+		return;
+	}
+	ixp4xx_timer_register(base, timer_irq, timer_freq);
+}
+EXPORT_SYMBOL_GPL(ixp4xx_timer_setup);
diff --git a/include/linux/platform_data/timer-ixp4xx.h b/include/linux/platform_data/timer-ixp4xx.h
new file mode 100644
index 000000000000..ee92ae7edaed
--- /dev/null
+++ b/include/linux/platform_data/timer-ixp4xx.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TIMER_IXP4XX_H
+#define __TIMER_IXP4XX_H
+
+#include <linux/ioport.h>
+
+void __init ixp4xx_timer_setup(resource_size_t timerbase,
+			       int timer_irq,
+			       unsigned int timer_freq);
+
+#endif
-- 
2.20.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply index

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-03 21:41 [PATCH 00/17 v1] ARM: ixp4xx: Modernize and DT support Linus Walleij
2019-02-03 21:41 ` [PATCH 01/17 v1] ARM: ixp4xx: Convert to MULTI_IRQ_HANDLER Linus Walleij
2019-02-03 21:41 ` [PATCH 02/17 v1] ARM: ixp4xx: Pass IRQ resource to beeper Linus Walleij
2019-02-03 21:41 ` [PATCH 03/17 v1] ARM: ixp4xx: Convert to SPARSE_IRQ Linus Walleij
2019-02-03 21:41 ` [PATCH 04/17 v1] irqchip: Add driver for IXP4xx Linus Walleij
2019-02-11 15:30   ` Marc Zyngier
2019-02-11 20:58     ` Linus Walleij
2019-02-11 22:11       ` Marc Zyngier
2019-02-18  7:06         ` khalasa
2019-02-18  7:16           ` Linus Walleij
2019-02-18  7:35             ` khalasa
2019-02-18  9:40             ` Arnd Bergmann
2019-02-18 12:03               ` khalasa
2019-02-18 12:44                 ` Arnd Bergmann
2019-02-19  6:51                   ` khalasa
2019-02-19  9:46                     ` Arnd Bergmann
2019-02-20  7:35                       ` khalasa
2019-02-18  9:18         ` Arnd Bergmann
2019-02-03 21:41 ` [PATCH 05/17 v1] gpio: ixp4xx: Add driver for the IXP4xx GPIO Linus Walleij
2019-02-06 16:03   ` Bartosz Golaszewski
2019-02-21  8:50     ` Linus Walleij
2019-02-03 21:41 ` [PATCH 06/17 v1] ARM: ixp4xx: Switch to use new IRQ+GPIO drivers Linus Walleij
2019-02-03 21:41 ` Linus Walleij [this message]
2019-02-03 21:41 ` [PATCH 08/17 v1] ARM: ixp4xx: Switch to use new timer driver Linus Walleij
2019-02-03 21:41 ` [PATCH 09/17 v1] irqchip: ixp4xx: Add DT bindings Linus Walleij
2019-02-18 21:25   ` Rob Herring
2019-02-03 21:41 ` [PATCH 10/17 v1] irqchip: ixp4xx: Add OF initialization support Linus Walleij
2019-02-03 21:41 ` [PATCH 11/17 v1] clocksource/drivers/ixp4xx: Add DT bindings Linus Walleij
2019-02-18 21:26   ` Rob Herring
2019-02-18 22:10     ` Daniel Lezcano
2019-02-03 21:42 ` [PATCH 12/17 v1] clocksource/drivers/ixp4xx: Add OF initialization support Linus Walleij
2019-02-11 11:26   ` Daniel Lezcano
2019-02-03 21:42 ` [PATCH 13/17 v1] gpio: ixp4xx: Add DT bindings Linus Walleij
2019-02-06 16:05   ` Bartosz Golaszewski
2019-02-18 21:27   ` Rob Herring
2019-02-03 21:42 ` [PATCH 14/17 v1] gpio: ixp4xx: Add OF probing support Linus Walleij
2019-02-06 16:13   ` Bartosz Golaszewski
2019-02-21  8:55     ` Linus Walleij
2019-02-03 21:42 ` [PATCH 15/17 v1] ARM: ixp4xx: Add DT bindings Linus Walleij
2019-02-04 15:16   ` Rob Herring
2019-02-08 19:37     ` Linus Walleij
2019-02-03 21:42 ` [PATCH 16/17 v1] ARM: ixp4xx: Add device tree boot support Linus Walleij
2019-02-03 21:42 ` [PATCH 17/17 v1] RFC: ARM: dts: Add some initial IXP4xx device trees Linus Walleij

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190203214205.13594-8-linus.walleij@linaro.org \
    --to=linus.walleij@linaro.org \
    --cc=arnd@arndb.de \
    --cc=daniel.lezcano@linaro.org \
    --cc=kaloz@openwrt.org \
    --cc=khalasa@piap.pl \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=olof@lixom.net \
    --cc=tglx@linutronix.de \
    --cc=tharvey@gateworks.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org infradead-linux-arm-kernel@archiver.kernel.org
	public-inbox-index linux-arm-kernel


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox