diff mbox

[1/9] clocksource: time-armada-370-xp: Marvell Armada 370/XP SoC timer driver

Message ID 1341243574-3258-2-git-send-email-thomas.petazzoni@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Thomas Petazzoni July 2, 2012, 3:39 p.m. UTC
From: Gregory Clement <gregory.clement@free-electrons.com>

Timer 0 is used as free-running clocksource, while timer 1 is used as
clock_event_device.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Lior Amsalem <alior@marvell.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: John Stultz <johnstul@us.ibm.com>
---
 drivers/clocksource/Kconfig              |    3 +
 drivers/clocksource/Makefile             |    3 +-
 drivers/clocksource/time-armada-370-xp.c |  226 ++++++++++++++++++++++++++++++
 include/linux/time-armada-370-xp.h       |   18 +++
 4 files changed, 249 insertions(+), 1 deletion(-)
 create mode 100644 drivers/clocksource/time-armada-370-xp.c
 create mode 100644 include/linux/time-armada-370-xp.h

Comments

Thomas Gleixner July 2, 2012, 5:40 p.m. UTC | #1
On Mon, 2 Jul 2012, Thomas Petazzoni wrote:

> From: Gregory Clement <gregory.clement@free-electrons.com>
> 
> Timer 0 is used as free-running clocksource, while timer 1 is used as
> clock_event_device.
> 
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Signed-off-by: Lior Amsalem <alior@marvell.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Andrew Lunn July 3, 2012, 3:12 p.m. UTC | #2
> +{
> +	u32 u;
> +	struct device_node *np;
> +	unsigned int timer_clk;
> +	int ret;
> +	np = of_find_compatible_node(NULL, NULL, "marvell,timer");

Hi Thomas

"marvell,timer" is too generic. I would suggest using
marvell,armada-370-xp-timer, the same prefix as for the system
controller. It allows us to extend the code to handle Orion platforms,
in the same way the system controller does.

   Andrew
diff mbox

Patch

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 99c6b20..b323631 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -16,6 +16,9 @@  config CLKSRC_MMIO
 config DW_APB_TIMER
 	bool
 
+config ARMADA_370_XP_TIMER
+	bool
+
 config CLKSRC_DBX500_PRCMU
 	bool "Clocksource PRCMU Timer"
 	depends on UX500_SOC_DB8500
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index dd3e661..022015c 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -10,4 +10,5 @@  obj-$(CONFIG_EM_TIMER_STI)	+= em_sti.o
 obj-$(CONFIG_CLKBLD_I8253)	+= i8253.o
 obj-$(CONFIG_CLKSRC_MMIO)	+= mmio.o
 obj-$(CONFIG_DW_APB_TIMER)	+= dw_apb_timer.o
-obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
\ No newline at end of file
+obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
+obj-$(CONFIG_ARMADA_370_XP_TIMER)	+= time-armada-370-xp.o
diff --git a/drivers/clocksource/time-armada-370-xp.c b/drivers/clocksource/time-armada-370-xp.c
new file mode 100644
index 0000000..1292aa3
--- /dev/null
+++ b/drivers/clocksource/time-armada-370-xp.c
@@ -0,0 +1,226 @@ 
+/*
+ * Marvell Armada 370/XP SoC timer handling.
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Lior Amsalem <alior@marvell.com>
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * Timer 0 is used as free-running clocksource, while timer 1 is
+ * used as clock_event_device.
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <asm/sched_clock.h>
+
+/*
+ * Timer block registers.
+ */
+#define TIMER_CTRL_OFF		0x0000
+#define  TIMER0_EN		 0x0001
+#define  TIMER0_RELOAD_EN	 0x0002
+#define  TIMER0_25MHZ            0x0800
+#define  TIMER0_DIV(div)         ((div) << 19)
+#define  TIMER1_EN		 0x0004
+#define  TIMER1_RELOAD_EN	 0x0008
+#define  TIMER1_25MHZ            0x1000
+#define  TIMER1_DIV(div)         ((div) << 22)
+#define TIMER_EVENTS_STATUS	0x0004
+#define  TIMER0_CLR_MASK         (~0x1)
+#define  TIMER1_CLR_MASK         (~0x100)
+#define TIMER0_RELOAD_OFF	0x0010
+#define TIMER0_VAL_OFF		0x0014
+#define TIMER1_RELOAD_OFF	0x0018
+#define TIMER1_VAL_OFF		0x001c
+
+/* Global timers are connected to the coherency fabric clock, and the
+   below divider reduces their incrementing frequency. */
+#define TIMER_DIVIDER_SHIFT     5
+#define TIMER_DIVIDER           (1 << TIMER_DIVIDER_SHIFT)
+
+/*
+ * SoC-specific data.
+ */
+static void __iomem *timer_base;
+static int timer_irq;
+
+/*
+ * Number of timer ticks per jiffy.
+ */
+static u32 ticks_per_jiffy;
+
+static u32 notrace armada_370_xp_read_sched_clock(void)
+{
+	return ~readl(timer_base + TIMER0_VAL_OFF);
+}
+
+/*
+ * Clockevent handling.
+ */
+static int
+armada_370_xp_clkevt_next_event(unsigned long delta,
+				struct clock_event_device *dev)
+{
+	u32 u;
+
+	/*
+	 * Clear clockevent timer interrupt.
+	 */
+	writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
+
+	/*
+	 * Setup new clockevent timer value.
+	 */
+	writel(delta, timer_base + TIMER1_VAL_OFF);
+
+	/*
+	 * Enable the timer.
+	 */
+	u = readl(timer_base + TIMER_CTRL_OFF);
+	u = ((u & ~TIMER1_RELOAD_EN) | TIMER1_EN |
+	     TIMER1_DIV(TIMER_DIVIDER_SHIFT));
+	writel(u, timer_base + TIMER_CTRL_OFF);
+
+	return 0;
+}
+
+static void
+armada_370_xp_clkevt_mode(enum clock_event_mode mode,
+			  struct clock_event_device *dev)
+{
+	u32 u;
+
+	if (mode == CLOCK_EVT_MODE_PERIODIC) {
+		/*
+		 * Setup timer to fire at 1/HZ intervals.
+		 */
+		writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD_OFF);
+		writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL_OFF);
+
+		/*
+		 * Enable timer.
+		 */
+		u = readl(timer_base + TIMER_CTRL_OFF);
+
+		writel((u | TIMER1_EN | TIMER1_RELOAD_EN |
+			TIMER1_DIV(TIMER_DIVIDER_SHIFT)),
+		       timer_base + TIMER_CTRL_OFF);
+	} else {
+		/*
+		 * Disable timer.
+		 */
+		u = readl(timer_base + TIMER_CTRL_OFF);
+		writel(u & ~TIMER1_EN, timer_base + TIMER_CTRL_OFF);
+
+		/*
+		 * ACK pending timer interrupt.
+		 */
+		writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
+
+	}
+}
+
+static struct clock_event_device armada_370_xp_clkevt = {
+	.name		= "armada_370_xp_tick",
+	.features	= CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+	.shift		= 32,
+	.rating		= 300,
+	.set_next_event	= armada_370_xp_clkevt_next_event,
+	.set_mode	= armada_370_xp_clkevt_mode,
+};
+
+static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id)
+{
+	/*
+	 * ACK timer interrupt and call event handler.
+	 */
+
+	writel(TIMER1_CLR_MASK, timer_base + TIMER_EVENTS_STATUS);
+	armada_370_xp_clkevt.event_handler(&armada_370_xp_clkevt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction armada_370_xp_timer_irq = {
+	.name		= "armada_370_xp_tick",
+	.flags		= IRQF_DISABLED | IRQF_TIMER,
+	.handler	= armada_370_xp_timer_interrupt
+};
+
+void __init armada_370_xp_timer_init(void)
+{
+	u32 u;
+	struct device_node *np;
+	unsigned int timer_clk;
+	int ret;
+	np = of_find_compatible_node(NULL, NULL, "marvell,timer");
+	timer_base = of_iomap(np, 0);
+	WARN_ON(!timer_base);
+
+	if (of_find_property(np, "marvell,timer-25Mhz", NULL)) {
+		/* The fixed 25MHz timer is available so let's use it */
+		u = readl(timer_base + TIMER_CTRL_OFF);
+		writel(u | TIMER0_25MHZ | TIMER1_25MHZ,
+		       timer_base + TIMER_CTRL_OFF);
+		timer_clk = 25000000;
+	} else {
+		u32 clk = 0;
+		ret = of_property_read_u32(np, "clock-frequency", &clk);
+		WARN_ON(!clk || ret < 0);
+		u = readl(timer_base + TIMER_CTRL_OFF);
+		writel(u & ~(TIMER0_25MHZ | TIMER1_25MHZ),
+		       timer_base + TIMER_CTRL_OFF);
+		timer_clk = clk / TIMER_DIVIDER;
+	}
+
+	/* We use timer 0 as clocksource, and timer 1 for
+	   clockevents */
+	timer_irq = irq_of_parse_and_map(np, 1);
+
+	ticks_per_jiffy = (timer_clk + HZ / 2) / HZ;
+
+	/*
+	 * Set scale and timer for sched_clock.
+	 */
+	setup_sched_clock(armada_370_xp_read_sched_clock, 32, timer_clk);
+
+	/*
+	 * Setup free-running clocksource timer (interrupts
+	 * disabled).
+	 */
+	writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
+	writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
+
+	u = readl(timer_base + TIMER_CTRL_OFF);
+
+	writel((u | TIMER0_EN | TIMER0_RELOAD_EN |
+		TIMER0_DIV(TIMER_DIVIDER_SHIFT)), timer_base + TIMER_CTRL_OFF);
+
+	clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
+			      "armada_370_xp_clocksource",
+			      timer_clk, 300, 32, clocksource_mmio_readl_down);
+
+	/*
+	 * Setup clockevent timer (interrupt-driven).
+	 */
+	setup_irq(timer_irq, &armada_370_xp_timer_irq);
+	armada_370_xp_clkevt.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&armada_370_xp_clkevt,
+					timer_clk, 1, 0xfffffffe);
+}
+
diff --git a/include/linux/time-armada-370-xp.h b/include/linux/time-armada-370-xp.h
new file mode 100644
index 0000000..dfdfdc0
--- /dev/null
+++ b/include/linux/time-armada-370-xp.h
@@ -0,0 +1,18 @@ 
+/*
+ * Marvell Armada 370/XP SoC timer handling.
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Lior Amsalem <alior@marvell.com>
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ */
+#ifndef __TIME_ARMADA_370_XPPRCMU_H
+#define __TIME_ARMADA_370_XPPRCMU_H
+
+#include <linux/init.h>
+
+void __init armada_370_xp_timer_init(void);
+
+#endif