initial suport for Alphascale ASM9260

In some cases asm9260 looks similar to iMX2x. One of exceptions is timer controller. So this patch introduces new driver for this special case.

Signed-off-by Oleksij Rempel <[email protected]>

---
 drivers/clocksource/Kconfig         |   4 +
 drivers/clocksource/Makefile        |   1 +
 drivers/clocksource/asm9260_timer.c | 234 ++++++++++++++++++++++++++++++++++++
 3 files changed, 239 insertions(+)
 create mode 100644 drivers/clocksource/asm9260_timer.c

drivers/clocksource/Kconfig +4 -0

index cfd6519..6a03d34 100644
@@ -216,4 +216,8 @@ config CLKSRC_VERSATILE
 	  ARM Versatile, RealView and Versatile Express reference
 	  platforms.
 
+config ASM9260_TIMER
+	select CLKSRC_MMIO
+	bool
+
 endmenu

drivers/clocksource/Makefile +1 -0

index 7fd9fd1..fc93854 100644
@@ -44,3 +44,4 @@ obj-$(CONFIG_CLKSRC_METAG_GENERIC)	+= metag_generic.o
 obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST)	+= dummy_timer.o
 obj-$(CONFIG_ARCH_KEYSTONE)		+= timer-keystone.o
 obj-$(CONFIG_CLKSRC_VERSATILE)		+= versatile.o
+obj-$(CONFIG_ASM9260_TIMER)		+= asm9260_timer.o

drivers/clocksource/asm9260_timer.c new file +89 -0

new file mode 100644
index 0000000..1b16e00
@@ -0,0 +1,234 @@
+/*
+ * Copyright (C) 2014 Oleksij Rempel <[email protected]>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/bitops.h>
+
+
+/*
+ * this device provide 4 offsets for each register:
+ * 0x0 - plain read write mode
+ * 0x4 - set mode, OR logic.
+ * 0x8 - clr mode, XOR logic.
+ * 0xc - togle mode.
+ */
+#define SET_REG 4
+#define CLR_REG 8
+
+#define HW_IR           0x0000 /* RW. Interrupt */
+#define BM_IR_CR0	BIT(4)
+#define BM_IR_MR3	BIT(3)
+#define BM_IR_MR2	BIT(2)
+#define BM_IR_MR1	BIT(1)
+#define BM_IR_MR0	BIT(0)
+
+#define HW_TCR		0x0010 /* RW. Timer controller */
+/* BM_C*_RST
+ * Timer Counter and the Prescale Counter are synchronously reset on the
+ * next positive edge of PCLK. The counters remain reset until TCR[1] is
+ * returned to zero. */
+#define BM_C3_RST	BIT(7)
+#define BM_C2_RST	BIT(6)
+#define BM_C1_RST	BIT(5)
+#define BM_C0_RST	BIT(4)
+/* BM_C*_EN
+ * 1 - Timer Counter and Prescale Counter are enabled for counting
+ * 0 - counters are disabled */
+#define BM_C3_EN	BIT(3)
+#define BM_C2_EN	BIT(2)
+#define BM_C1_EN	BIT(1)
+#define BM_C0_EN	BIT(0)
+
+#define HW_DIR		0x0020 /* RW. Direction? */
+/* 00 - count up
+ * 01 - count down
+ * 10 - ?? 2^n/2 */
+#define BM_DIR0_SHIFT	0
+#define BM_DIR1_SHIFT	4
+#define BM_DIR2_SHIFT	8
+#define BM_DIR3_SHIFT	12
+
+#define HW_TC0		0x0030 /* RO. Timer counter 0 */
+/* HW_TC*. Timer counter owerflow (0xffff.ffff to 0x0000.0000) do not generate
+ * interrupt. This registers can be used to detect overflow */
+#define HW_TC1          0x0040
+#define HW_TC2		0x0050
+#define HW_TC3		0x0060
+
+#define HW_PR		0x0070 /* RW. prescaler */
+#define HW_PC		0x0080 /* RO. Prescaler counter */
+#define HW_MCR		0x0090 /* RW. Match control */
+/* enable interrupt on match */
+#define BM_MCR_INT_EN(n)	(1 << (n * 3 + 0))
+/* enable TC reset on match */
+#define BM_MCR_RES_EN(n)	(1 << (n * 3 + 1))
+/* enable stop TC on match */
+#define BM_MCR_STOP_EN(n)	(1 << (n * 3 + 2))
+
+#define HW_MR0		0x00a0 /* RW. Match reg */
+#define HW_MR1		0x00b0
+#define HW_MR2		0x00C0
+#define HW_MR3		0x00D0
+#define HW_CCR		0x00E0 /* RW. Capture control */
+#define HW_CR0		0x00F0 /* RO. Capture reg */

drivers/clocksource/asm9260_timer.c new file +71 -0

+
+static int asm9260_timer_set_next_event(unsigned long delta,
+					 struct clock_event_device *dev)
+{
+	/* configure match count for TC0 */
+	writel_relaxed(delta, base + HW_MR0);
+	/* enable TC0 */
+	writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG);
+	return 0;
+}
+
+static void asm9260_timer_set_mode(enum clock_event_mode mode,
+				    struct clock_event_device *evt)
+{
+	/* stop timer0 */
+	writel_relaxed(BM_C0_EN, base + HW_TCR + CLR_REG);
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		/* disable reset and stop on match */
+		writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0),
+				base + HW_MCR + CLR_REG);
+		/* configure match count for TC0 */
+		writel_relaxed(ticks_per_jiffy, base + HW_MR0);
+		/* enable TC0 */
+		writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG);
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		/* enable reset and stop on match */
+		writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0),
+				base + HW_MCR + SET_REG);
+		break;
+	default:
+		break;
+	}
+}
+
+static struct clock_event_device asm9260_clockevent_device = {
+	.name		= "asm9260-clockevent-dev",
+	.rating		= 200,
+	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.set_next_event	= asm9260_timer_set_next_event,
+	.set_mode	= asm9260_timer_set_mode,
+};
+
+static irqreturn_t asm9260_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = &asm9260_clockevent_device;
+
+	evt->event_handler(evt);
+
+	writel_relaxed(BM_IR_MR0, base + HW_IR);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction asm9260_timer_irq = {
+	.name		= "asm9260-clockevent-dev",
+	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= asm9260_timer_interrupt,
+};
+
+/*
+ * ---------------------------------------------------------------------------
+ * Timer initialization
+ * ---------------------------------------------------------------------------
+ */
+
+static void __init asm9260_clockevent_init(struct clk *clk)
+{
+	unsigned long rate = clk_get_rate(clk);

drivers/clocksource/asm9260_timer.c new file +17 -0

+
+	clocksource_mmio_init(base + HW_TC1,
+			"asm9260-clocksource", hz,
+			200, 32, clocksource_mmio_readl_up);
+
+	/* Seems like we can't use counter without match register even if
+	 * actions for MR are disabled. */
+	writel_relaxed(0xffffffff, base + HW_MR1);
+	/* enable TC1 */
+	writel_relaxed(BM_C1_EN, base + HW_TCR + SET_REG);
+}
+
+static void __init asm9260_timer_init(struct device_node *np)
+{
+	int irq;
+	struct clk *clk;
+	struct resource res;

drivers/clocksource/asm9260_timer.c new file +8 -0

+	/* enable interrupt for TC0 and clean setting for all other lines */
+	writel_relaxed(BM_MCR_INT_EN(0) , base + HW_MCR);
+
+	asm9260_clocksource_init(clk);
+	asm9260_clockevent_init(clk);
+}
+CLOCKSOURCE_OF_DECLARE(asm9260_timer, "alphascale,asm9260-timer",
+		asm9260_timer_init);

Quoted 128 lines

In some cases asm9260 looks similar to iMX2x. One of exceptions is timer controller. So this patch introduces new driver for this special case.

Signed-off-by Oleksij Rempel <[email protected]>

---
 drivers/clocksource/Kconfig         |   4 +
 drivers/clocksource/Makefile        |   1 +
 drivers/clocksource/asm9260_timer.c | 234 ++++++++++++++++++++++++++++++++++++
 3 files changed, 239 insertions(+)
 create mode 100644 drivers/clocksource/asm9260_timer.c

drivers/clocksource/Kconfig +4 -0

index cfd6519..6a03d34 100644
@@ -216,4 +216,8 @@ config CLKSRC_VERSATILE
 	  ARM Versatile, RealView and Versatile Express reference
 	  platforms.
 
+config ASM9260_TIMER
+	select CLKSRC_MMIO
+	bool
+
 endmenu

drivers/clocksource/Makefile +1 -0

index 7fd9fd1..fc93854 100644
@@ -44,3 +44,4 @@ obj-$(CONFIG_CLKSRC_METAG_GENERIC)	+= metag_generic.o
 obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST)	+= dummy_timer.o
 obj-$(CONFIG_ARCH_KEYSTONE)		+= timer-keystone.o
 obj-$(CONFIG_CLKSRC_VERSATILE)		+= versatile.o
+obj-$(CONFIG_ASM9260_TIMER)		+= asm9260_timer.o

drivers/clocksource/asm9260_timer.c new file +89 -0

new file mode 100644
index 0000000..1b16e00
@@ -0,0 +1,234 @@
+/*
+ * Copyright (C) 2014 Oleksij Rempel <[email protected]>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/bitops.h>
+
+
+/*
+ * this device provide 4 offsets for each register:
+ * 0x0 - plain read write mode
+ * 0x4 - set mode, OR logic.
+ * 0x8 - clr mode, XOR logic.
+ * 0xc - togle mode.
+ */
+#define SET_REG 4
+#define CLR_REG 8
+
+#define HW_IR           0x0000 /* RW. Interrupt */
+#define BM_IR_CR0	BIT(4)
+#define BM_IR_MR3	BIT(3)
+#define BM_IR_MR2	BIT(2)
+#define BM_IR_MR1	BIT(1)
+#define BM_IR_MR0	BIT(0)
+
+#define HW_TCR		0x0010 /* RW. Timer controller */
+/* BM_C*_RST
+ * Timer Counter and the Prescale Counter are synchronously reset on the
+ * next positive edge of PCLK. The counters remain reset until TCR[1] is
+ * returned to zero. */
+#define BM_C3_RST	BIT(7)
+#define BM_C2_RST	BIT(6)
+#define BM_C1_RST	BIT(5)
+#define BM_C0_RST	BIT(4)
+/* BM_C*_EN
+ * 1 - Timer Counter and Prescale Counter are enabled for counting
+ * 0 - counters are disabled */
+#define BM_C3_EN	BIT(3)
+#define BM_C2_EN	BIT(2)
+#define BM_C1_EN	BIT(1)
+#define BM_C0_EN	BIT(0)
+
+#define HW_DIR		0x0020 /* RW. Direction? */
+/* 00 - count up
+ * 01 - count down
+ * 10 - ?? 2^n/2 */
+#define BM_DIR0_SHIFT	0
+#define BM_DIR1_SHIFT	4
+#define BM_DIR2_SHIFT	8
+#define BM_DIR3_SHIFT	12
+
+#define HW_TC0		0x0030 /* RO. Timer counter 0 */
+/* HW_TC*. Timer counter owerflow (0xffff.ffff to 0x0000.0000) do not generate
+ * interrupt. This registers can be used to detect overflow */
+#define HW_TC1          0x0040
+#define HW_TC2		0x0050
+#define HW_TC3		0x0060
+
+#define HW_PR		0x0070 /* RW. prescaler */
+#define HW_PC		0x0080 /* RO. Prescaler counter */
+#define HW_MCR		0x0090 /* RW. Match control */
+/* enable interrupt on match */
+#define BM_MCR_INT_EN(n)	(1 << (n * 3 + 0))
+/* enable TC reset on match */
+#define BM_MCR_RES_EN(n)	(1 << (n * 3 + 1))
+/* enable stop TC on match */
+#define BM_MCR_STOP_EN(n)	(1 << (n * 3 + 2))
+
+#define HW_MR0		0x00a0 /* RW. Match reg */
+#define HW_MR1		0x00b0
+#define HW_MR2		0x00C0
+#define HW_MR3		0x00D0
+#define HW_CCR		0x00E0 /* RW. Capture control */
+#define HW_CR0		0x00F0 /* RO. Capture reg */

drivers/clocksource/asm9260_timer.c line 99

Quoted 10 lines

drivers/clocksource/asm9260_timer.c new file +10 -0

+#define HW_CR1		0x0100
+#define HW_CR2		0x0110
+#define HW_CR3		0x0120
+#define HW_EMR		0x0130 /* RW. External Match */
+#define HW_PWMTH0	0x0140 /* RW. PWM width */
+#define HW_PWMTH1	0x0150
+#define HW_PWMTH2	0x0160
+#define HW_PWMTH3	0x0170
+#define HW_CTCR		0x0180 /* Counter control */
+#define HW_PWMC		0x0190 /* PWM control */

Please delete unused defines.

drivers/clocksource/asm9260_timer.c line 102

Quoted 3 lines

drivers/clocksource/asm9260_timer.c new file +3 -0

+
+static void __iomem *base;
+static unsigned long ticks_per_jiffy;

More elegant would be to put this in a struct which you pass to the functions.

Quoted 71 lines

drivers/clocksource/asm9260_timer.c new file +71 -0

+
+static int asm9260_timer_set_next_event(unsigned long delta,
+					 struct clock_event_device *dev)
+{
+	/* configure match count for TC0 */
+	writel_relaxed(delta, base + HW_MR0);
+	/* enable TC0 */
+	writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG);
+	return 0;
+}
+
+static void asm9260_timer_set_mode(enum clock_event_mode mode,
+				    struct clock_event_device *evt)
+{
+	/* stop timer0 */
+	writel_relaxed(BM_C0_EN, base + HW_TCR + CLR_REG);
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		/* disable reset and stop on match */
+		writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0),
+				base + HW_MCR + CLR_REG);
+		/* configure match count for TC0 */
+		writel_relaxed(ticks_per_jiffy, base + HW_MR0);
+		/* enable TC0 */
+		writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG);
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		/* enable reset and stop on match */
+		writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0),
+				base + HW_MCR + SET_REG);
+		break;
+	default:
+		break;
+	}
+}
+
+static struct clock_event_device asm9260_clockevent_device = {
+	.name		= "asm9260-clockevent-dev",
+	.rating		= 200,
+	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.set_next_event	= asm9260_timer_set_next_event,
+	.set_mode	= asm9260_timer_set_mode,
+};
+
+static irqreturn_t asm9260_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = &asm9260_clockevent_device;
+
+	evt->event_handler(evt);
+
+	writel_relaxed(BM_IR_MR0, base + HW_IR);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction asm9260_timer_irq = {
+	.name		= "asm9260-clockevent-dev",
+	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= asm9260_timer_interrupt,
+};
+
+/*
+ * ---------------------------------------------------------------------------
+ * Timer initialization
+ * ---------------------------------------------------------------------------
+ */
+
+static void __init asm9260_clockevent_init(struct clk *clk)
+{
+	unsigned long rate = clk_get_rate(clk);

drivers/clocksource/asm9260_timer.c line 183

Quoted 10 lines

drivers/clocksource/asm9260_timer.c new file +10 -0

+
+	ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
+	asm9260_clockevent_device.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&asm9260_clockevent_device,
+					rate, 0x2c00, 0xfffffffe);
+}
+
+static void __init asm9260_clocksource_init(struct clk *clk)
+{
+	unsigned long hz = clk_get_rate(clk);

Why not call this in the asm9260_timer_init functions and pass the rate to clockevent_init and clocksource_init?

Quoted 17 lines

drivers/clocksource/asm9260_timer.c new file +17 -0

+
+	clocksource_mmio_init(base + HW_TC1,
+			"asm9260-clocksource", hz,
+			200, 32, clocksource_mmio_readl_up);
+
+	/* Seems like we can't use counter without match register even if
+	 * actions for MR are disabled. */
+	writel_relaxed(0xffffffff, base + HW_MR1);
+	/* enable TC1 */
+	writel_relaxed(BM_C1_EN, base + HW_TCR + SET_REG);
+}
+
+static void __init asm9260_timer_init(struct device_node *np)
+{
+	int irq;
+	struct clk *clk;
+	struct resource res;

drivers/clocksource/asm9260_timer.c line 210

Quoted 10 lines

drivers/clocksource/asm9260_timer.c new file +10 -0

+	int ret;
+
+	of_address_to_resource(np, 0, &res);
+	if (!request_mem_region(res.start, resource_size(&res),
+				"asm9260-timer"))
+		panic("%s: unable to request mem region", np->name);
+
+	base = ioremap_nocache(res.start, resource_size(&res));
+	if (!base)
+		panic("%s: unable to map resource", np->name);

Why don't you use of_io_request_and_map instead of this block?

drivers/clocksource/asm9260_timer.c line 219

Quoted 9 lines

drivers/clocksource/asm9260_timer.c new file +9 -0

+
+	clk = of_clk_get(np, 0);
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		panic("Failed to enable clk!\n");
+
+	irq = irq_of_parse_and_map(np, 0);
+	setup_irq(irq, &asm9260_timer_irq);

Please use request_irq instead.

drivers/clocksource/asm9260_timer.c line 226

Quoted 7 lines

drivers/clocksource/asm9260_timer.c new file +7 -0

+
+	/* set all timers for count-up */
+	writel_relaxed(0, base + HW_DIR);
+	/* disable divider */
+	writel_relaxed(0, base + HW_PR);
+	/* make sure all timers use every rising PCLK edge. */
+	writel_relaxed(0, base + HW_CTCR);

Please use a define for this.

Quoted 9 lines

drivers/clocksource/asm9260_timer.c new file +8 -0

+	/* enable interrupt for TC0 and clean setting for all other lines */
+	writel_relaxed(BM_MCR_INT_EN(0) , base + HW_MCR);
+
+	asm9260_clocksource_init(clk);
+	asm9260_clockevent_init(clk);
+}
+CLOCKSOURCE_OF_DECLARE(asm9260_timer, "alphascale,asm9260-timer",
+		asm9260_timer_init);

Hi Matthias,

of_io_request_and_map should use "const char *name" instead of "char *name".

And thank you for your feed back. Well for all suggestions of all of you :)

Am 15.10.2014 um 23:31 schrieb Matthias Brugger:

Quoted 288 lines · Oleksij Rempel

Quoted 128 lines

In some cases asm9260 looks similar to iMX2x. One of exceptions is timer controller. So this patch introduces new driver for this special case.

Signed-off-by Oleksij Rempel <[email protected]>

---
 drivers/clocksource/Kconfig         |   4 +
 drivers/clocksource/Makefile        |   1 +
 drivers/clocksource/asm9260_timer.c | 234 ++++++++++++++++++++++++++++++++++++
 3 files changed, 239 insertions(+)
 create mode 100644 drivers/clocksource/asm9260_timer.c

drivers/clocksource/Kconfig +4 -0

index cfd6519..6a03d34 100644
@@ -216,4 +216,8 @@ config CLKSRC_VERSATILE
       ARM Versatile, RealView and Versatile Express reference
       platforms.
 
+config ASM9260_TIMER
+    select CLKSRC_MMIO
+    bool
+
 endmenu

drivers/clocksource/Makefile +1 -0

index 7fd9fd1..fc93854 100644
@@ -44,3 +44,4 @@ obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o
 obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST)       += dummy_timer.o
 obj-$(CONFIG_ARCH_KEYSTONE)         += timer-keystone.o
 obj-$(CONFIG_CLKSRC_VERSATILE)              += versatile.o
+obj-$(CONFIG_ASM9260_TIMER)         += asm9260_timer.o

drivers/clocksource/asm9260_timer.c new file +89 -0

new file mode 100644
index 0000000..1b16e00
@@ -0,0 +1,234 @@
+/*
+ * Copyright (C) 2014 Oleksij Rempel <[email protected]>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/bitops.h>
+
+
+/*
+ * this device provide 4 offsets for each register:
+ * 0x0 - plain read write mode
+ * 0x4 - set mode, OR logic.
+ * 0x8 - clr mode, XOR logic.
+ * 0xc - togle mode.
+ */
+#define SET_REG 4
+#define CLR_REG 8
+
+#define HW_IR           0x0000 /* RW. Interrupt */
+#define BM_IR_CR0   BIT(4)
+#define BM_IR_MR3   BIT(3)
+#define BM_IR_MR2   BIT(2)
+#define BM_IR_MR1   BIT(1)
+#define BM_IR_MR0   BIT(0)
+
+#define HW_TCR              0x0010 /* RW. Timer controller */
+/* BM_C*_RST
+ * Timer Counter and the Prescale Counter are synchronously reset on the
+ * next positive edge of PCLK. The counters remain reset until TCR[1] is
+ * returned to zero. */
+#define BM_C3_RST   BIT(7)
+#define BM_C2_RST   BIT(6)
+#define BM_C1_RST   BIT(5)
+#define BM_C0_RST   BIT(4)
+/* BM_C*_EN
+ * 1 - Timer Counter and Prescale Counter are enabled for counting
+ * 0 - counters are disabled */
+#define BM_C3_EN    BIT(3)
+#define BM_C2_EN    BIT(2)
+#define BM_C1_EN    BIT(1)
+#define BM_C0_EN    BIT(0)
+
+#define HW_DIR              0x0020 /* RW. Direction? */
+/* 00 - count up
+ * 01 - count down
+ * 10 - ?? 2^n/2 */
+#define BM_DIR0_SHIFT       0
+#define BM_DIR1_SHIFT       4
+#define BM_DIR2_SHIFT       8
+#define BM_DIR3_SHIFT       12
+
+#define HW_TC0              0x0030 /* RO. Timer counter 0 */
+/* HW_TC*. Timer counter owerflow (0xffff.ffff to 0x0000.0000) do not generate
+ * interrupt. This registers can be used to detect overflow */
+#define HW_TC1          0x0040
+#define HW_TC2              0x0050
+#define HW_TC3              0x0060
+
+#define HW_PR               0x0070 /* RW. prescaler */
+#define HW_PC               0x0080 /* RO. Prescaler counter */
+#define HW_MCR              0x0090 /* RW. Match control */
+/* enable interrupt on match */
+#define BM_MCR_INT_EN(n)    (1 << (n * 3 + 0))
+/* enable TC reset on match */
+#define BM_MCR_RES_EN(n)    (1 << (n * 3 + 1))
+/* enable stop TC on match */
+#define BM_MCR_STOP_EN(n)   (1 << (n * 3 + 2))
+
+#define HW_MR0              0x00a0 /* RW. Match reg */
+#define HW_MR1              0x00b0
+#define HW_MR2              0x00C0
+#define HW_MR3              0x00D0
+#define HW_CCR              0x00E0 /* RW. Capture control */
+#define HW_CR0              0x00F0 /* RO. Capture reg */

drivers/clocksource/asm9260_timer.c line 99

Quoted 10 lines

drivers/clocksource/asm9260_timer.c new file +10 -0

+#define HW_CR1              0x0100
+#define HW_CR2              0x0110
+#define HW_CR3              0x0120
+#define HW_EMR              0x0130 /* RW. External Match */
+#define HW_PWMTH0   0x0140 /* RW. PWM width */
+#define HW_PWMTH1   0x0150
+#define HW_PWMTH2   0x0160
+#define HW_PWMTH3   0x0170
+#define HW_CTCR             0x0180 /* Counter control */
+#define HW_PWMC             0x0190 /* PWM control */

Please delete unused defines.

drivers/clocksource/asm9260_timer.c line 102

Quoted 3 lines

drivers/clocksource/asm9260_timer.c new file +3 -0

+
+static void __iomem *base;
+static unsigned long ticks_per_jiffy;

More elegant would be to put this in a struct which you pass to the functions.

Quoted 71 lines

drivers/clocksource/asm9260_timer.c new file +71 -0

+
+static int asm9260_timer_set_next_event(unsigned long delta,
+                                     struct clock_event_device *dev)
+{
+    /* configure match count for TC0 */
+    writel_relaxed(delta, base + HW_MR0);
+    /* enable TC0 */
+    writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG);
+    return 0;
+}
+
+static void asm9260_timer_set_mode(enum clock_event_mode mode,
+                                struct clock_event_device *evt)
+{
+    /* stop timer0 */
+    writel_relaxed(BM_C0_EN, base + HW_TCR + CLR_REG);
+
+    switch (mode) {
+    case CLOCK_EVT_MODE_PERIODIC:
+            /* disable reset and stop on match */
+            writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0),
+                            base + HW_MCR + CLR_REG);
+            /* configure match count for TC0 */
+            writel_relaxed(ticks_per_jiffy, base + HW_MR0);
+            /* enable TC0 */
+            writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG);
+            break;
+    case CLOCK_EVT_MODE_ONESHOT:
+            /* enable reset and stop on match */
+            writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0),
+                            base + HW_MCR + SET_REG);
+            break;
+    default:
+            break;
+    }
+}
+
+static struct clock_event_device asm9260_clockevent_device = {
+    .name           = "asm9260-clockevent-dev",
+    .rating         = 200,
+    .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+    .set_next_event = asm9260_timer_set_next_event,
+    .set_mode       = asm9260_timer_set_mode,
+};
+
+static irqreturn_t asm9260_timer_interrupt(int irq, void *dev_id)
+{
+    struct clock_event_device *evt = &asm9260_clockevent_device;
+
+    evt->event_handler(evt);
+
+    writel_relaxed(BM_IR_MR0, base + HW_IR);
+
+    return IRQ_HANDLED;
+}
+
+static struct irqaction asm9260_timer_irq = {
+    .name           = "asm9260-clockevent-dev",
+    .flags          = IRQF_TIMER | IRQF_IRQPOLL,
+    .handler        = asm9260_timer_interrupt,
+};
+
+/*
+ * ---------------------------------------------------------------------------
+ * Timer initialization
+ * ---------------------------------------------------------------------------
+ */
+
+static void __init asm9260_clockevent_init(struct clk *clk)
+{
+    unsigned long rate = clk_get_rate(clk);

drivers/clocksource/asm9260_timer.c line 183

Quoted 10 lines

drivers/clocksource/asm9260_timer.c new file +10 -0

+
+    ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
+    asm9260_clockevent_device.cpumask = cpumask_of(0);
+    clockevents_config_and_register(&asm9260_clockevent_device,
+                                    rate, 0x2c00, 0xfffffffe);
+}
+
+static void __init asm9260_clocksource_init(struct clk *clk)
+{
+    unsigned long hz = clk_get_rate(clk);

Why not call this in the asm9260_timer_init functions and pass the rate to clockevent_init and clocksource_init?

Quoted 17 lines

drivers/clocksource/asm9260_timer.c new file +17 -0

+
+    clocksource_mmio_init(base + HW_TC1,
+                    "asm9260-clocksource", hz,
+                    200, 32, clocksource_mmio_readl_up);
+
+    /* Seems like we can't use counter without match register even if
+     * actions for MR are disabled. */
+    writel_relaxed(0xffffffff, base + HW_MR1);
+    /* enable TC1 */
+    writel_relaxed(BM_C1_EN, base + HW_TCR + SET_REG);
+}
+
+static void __init asm9260_timer_init(struct device_node *np)
+{
+    int irq;
+    struct clk *clk;
+    struct resource res;

drivers/clocksource/asm9260_timer.c line 210

Quoted 10 lines

drivers/clocksource/asm9260_timer.c new file +10 -0

+    int ret;
+
+    of_address_to_resource(np, 0, &res);
+    if (!request_mem_region(res.start, resource_size(&res),
+                            "asm9260-timer"))
+            panic("%s: unable to request mem region", np->name);
+
+    base = ioremap_nocache(res.start, resource_size(&res));
+    if (!base)
+            panic("%s: unable to map resource", np->name);

Why don't you use of_io_request_and_map instead of this block?

drivers/clocksource/asm9260_timer.c line 219

Quoted 9 lines

drivers/clocksource/asm9260_timer.c new file +9 -0

+
+    clk = of_clk_get(np, 0);
+
+    ret = clk_prepare_enable(clk);
+    if (ret)
+            panic("Failed to enable clk!\n");
+
+    irq = irq_of_parse_and_map(np, 0);
+    setup_irq(irq, &asm9260_timer_irq);

Please use request_irq instead.

drivers/clocksource/asm9260_timer.c line 226

Quoted 7 lines

drivers/clocksource/asm9260_timer.c new file +7 -0

+
+    /* set all timers for count-up */
+    writel_relaxed(0, base + HW_DIR);
+    /* disable divider */
+    writel_relaxed(0, base + HW_PR);
+    /* make sure all timers use every rising PCLK edge. */
+    writel_relaxed(0, base + HW_CTCR);

Please use a define for this.

Quoted 9 lines

drivers/clocksource/asm9260_timer.c line 234

Quoted 9 lines

drivers/clocksource/asm9260_timer.c new file +8 -0

+    /* enable interrupt for TC0 and clean setting for all other lines */
+    writel_relaxed(BM_MCR_INT_EN(0) , base + HW_MCR);
+
+    asm9260_clocksource_init(clk);
+    asm9260_clockevent_init(clk);
+}
+CLOCKSOURCE_OF_DECLARE(asm9260_timer, "alphascale,asm9260-timer",
+            asm9260_timer_init);

--
Regards,
Oleksij