[PATCH v3 0/3] *** Fix warning from kbuild test robot ***

[PATCH v3 0/3] *** Fix warning from kbuild test robot ***

[Rick Chen]

*** Fix warnings when make with ARCH=x86_64 from auto build test ***

rick (3):
  clocksource/drivers/atcpit100: Add andestech atcpit100 timer
  clocksource/drivers/Kconfig: Support andestech atcpit100 timer
  dt-bindings: timer: Add andestech atcpit100 timer binding doc

 .../bindings/timer/andestech,atcpit100-timer.txt   |  31 ++++
 drivers/clocksource/Kconfig                        |   6 +
 drivers/clocksource/Makefile                       |   1 +
 drivers/clocksource/timer-atcpit100.c              | 199 +++++++++++++++++++++
 4 files changed, 237 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/timer/andestech,atcpit100-timer.txt
 create mode 100644 drivers/clocksource/timer-atcpit100.c

-- 
2.7.4

[PATCH v3 1/3] clocksource/drivers/atcpit100: Add andestech atcpit100 timer

[Rick Chen]

ATCPIT100 is often used on the Andes architecture,
This timer provide 4 PIT channels. Each PIT channel is a
multi-function timer, can be configured as 32,16,8 bit timers
or PWM as well.

For system timer it will set 32-bit timer0 as clock source
and count downwards until underflow and restart again.

It also set 32-bit timer1 as clock event and count downwards
until condition match. It will generate an interrupt for
handling periodically.

Signed-off-by: Rick Chen <rickchen36@gmail.com>
Signed-off-by: Greentime Hu <green.hu@gmail.com>
---
 drivers/clocksource/timer-atcpit100.c | 199 ++++++++++++++++++++++++++++++++++
 1 file changed, 199 insertions(+)
 create mode 100644 drivers/clocksource/timer-atcpit100.c

diff --git a/drivers/clocksource/timer-atcpit100.c b/drivers/clocksource/timer-atcpit100.c
new file mode 100644
index 0000000..1a5538b
--- /dev/null
+++ b/drivers/clocksource/timer-atcpit100.c
@@ -0,0 +1,199 @@
+/*
+ *  Andestech ATCPIT100 Timer Device Driver Implementation
+ *
+ *  Copyright (C) 2016 Andes Technology Corporation
+ *
+ * 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.
+ *
+ *
+ */
+#include <linux/irq.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/cpufreq.h>
+#include <linux/sched.h>
+#include <linux/sched_clock.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+
+void __iomem *base;
+static u32 freq;
+
+/*
+ * Definition of register offsets
+ */
+
+/* ID and Revision Register */
+#define ID_REV		0x0
+
+/* Configuration Register */
+#define CFG		0x10
+
+/* Interrupt Enable Register */
+#define INT_EN		0x14
+#define CH_INT_EN(c, i)	((1<<i)<<(4*c))
+
+/* Interrupt Status Register */
+#define INT_STA		0x18
+#define CH_INT_STA(c, i)	((1<<i)<<(4*c))
+
+/* Channel Enable Register */
+#define CH_EN		0x1C
+#define CH_TMR_EN(c, t)	((1<<t)<<(4*c))
+
+/* Ch n Control REgister */
+#define CH_CTL(n)	(0x20+0x10*n)
+/* Channel clock source , bit 3 , 0:External clock , 1:APB clock */
+#define APB_CLK		(1<<3)
+/* Channel mode , bit 0~2 */
+#define TMR_32		1
+#define TMR_16		2
+#define TMR_8		3
+#define PWM		4
+
+#define CH_REL(n)	(0x24+0x10*n)
+#define CH_CNT(n)	(0x28+0x10*n)
+
+static unsigned long atcpit100_read_current_timer_down(void)
+{
+	return ~readl(base + CH_CNT(1));
+}
+
+static u64 notrace atcpit100_read_sched_clock_down(void)
+{
+	return atcpit100_read_current_timer_down();
+}
+
+static void atcpit100_clocksource_init(void)
+{
+	writel(0xffffffff, base + CH_REL(1));
+	writel(APB_CLK|TMR_32, base + CH_CTL(1));
+	writel(readl(base + CH_EN) | CH_TMR_EN(1, 0), base + CH_EN);
+	clocksource_mmio_init(base + CH_CNT(1),
+			      "atcpit100_tm1",
+			      freq,
+			      300, 32, clocksource_mmio_readl_down);
+	sched_clock_register(atcpit100_read_sched_clock_down, 32, freq);
+}
+
+static int atcpit100_set_next_event(unsigned long cycles,
+		struct clock_event_device *evt)
+{
+	writel(cycles, base + CH_REL(0));
+
+	return 0;
+}
+
+static int atcpit100_set_state_shutdown(struct clock_event_device *evt)
+{
+	writel(readl(base + CH_EN) & ~CH_TMR_EN(0, 0), base + CH_EN);
+
+	return 0;
+}
+static int atcpit100_set_state_periodic(struct clock_event_device *evt)
+{
+	writel(freq / HZ - 1, base + CH_CNT(0));
+	writel(freq / HZ - 1, base + CH_REL(0));
+	writel(readl(base + CH_EN) | CH_TMR_EN(0, 0), base + CH_EN);
+
+	return 0;
+}
+static int atcpit100_tick_resume(struct clock_event_device *evt)
+{
+	writel(readl(base + INT_STA) | CH_INT_STA(0, 0), base + INT_STA);
+	writel(readl(base + CH_EN) | CH_TMR_EN(0, 0), base + CH_EN);
+
+	return 0;
+}
+static int atcpit100_set_state_oneshot(struct clock_event_device *evt)
+{
+	writel(0xffffffff, base + CH_REL(0));
+	writel(readl(base + CH_EN) | CH_TMR_EN(0, 0), base + CH_EN);
+
+	return 0;
+}
+
+static struct clock_event_device clockevent_atcpit100 = {
+	.name		= "atcpit100_tm0",
+	.features       = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+	.shift		= 32,
+	.cpumask	= cpu_all_mask,
+	.set_next_event	= atcpit100_set_next_event,
+	.set_state_shutdown = atcpit100_set_state_shutdown,
+	.set_state_periodic = atcpit100_set_state_periodic,
+	.set_state_oneshot = atcpit100_set_state_oneshot,
+	.tick_resume = atcpit100_tick_resume,
+};
+
+static irqreturn_t timer1_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+
+	writel(readl(base + INT_STA) | CH_INT_STA(0, 0), base + INT_STA);
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction timer1_irq = {
+	.name		= "Timer Tick",
+	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= timer1_interrupt,
+	.dev_id		= &clockevent_atcpit100
+};
+
+static void __init atcpit100_clockevent_init(int irq)
+{
+	struct clock_event_device *evt = &clockevent_atcpit100;
+
+	evt->mult = div_sc(freq, NSEC_PER_SEC, evt->shift);
+	evt->max_delta_ns = clockevent_delta2ns(0xffffffff, evt);
+	evt->min_delta_ns = clockevent_delta2ns(3, evt);
+	clockevents_register_device(evt);
+	setup_irq(irq, &timer1_irq);
+}
+
+static int __init atcpit100_init(struct device_node *dev)
+{
+	int irq;
+
+	base = of_iomap(dev, 0);
+	if (!base) {
+		pr_warn("Can't remap registers");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(dev, "clock-frequency", &freq)) {
+		pr_warn("Can't read clock-frequency");
+		return -EINVAL;
+	}
+	irq = irq_of_parse_and_map(dev, 0);
+
+	if (irq <= 0) {
+		pr_warn("Failed to map timer IRQ\n");
+		return -EINVAL;
+	}
+	pr_info("ATCPIT100 timer 1 installed on IRQ %d, with clock %d at %d HZ. in %p\n",
+			irq, freq, HZ, base);
+	writel(APB_CLK|TMR_32, base + CH_CTL(0));
+	writel(readl(base + INT_EN) | CH_INT_EN(0, 0), base + INT_EN);
+	writel(readl(base + CH_EN) | CH_TMR_EN(0, 0), base + CH_EN);
+	atcpit100_clocksource_init();
+	atcpit100_clockevent_init(irq);
+
+	return 0;
+}
+
+TIMER_OF_DECLARE(atcpit100, "andestech,atcpit100", atcpit100_init);
-- 
2.7.4

Re: [PATCH v3 1/3] clocksource/drivers/atcpit100: Add andestech atcpit100 timer

[Daniel Lezcano]

On 07/11/2017 08:19, Rick Chen wrote:
> ATCPIT100 is often used on the Andes architecture,
> This timer provide 4 PIT channels. Each PIT channel is a
> multi-function timer, can be configured as 32,16,8 bit timers
> or PWM as well.
> 
> For system timer it will set 32-bit timer0 as clock source
> and count downwards until underflow and restart again.
> 
> It also set 32-bit timer1 as clock event and count downwards
> until condition match. It will generate an interrupt for
> handling periodically.
> 
> Signed-off-by: Rick Chen <rickchen36@gmail.com>
> Signed-off-by: Greentime Hu <green.hu@gmail.com>

Is it rick@andestech.com or rickchen36@gmail.com ?

Are you sending this patch as a hobbyist or on the behalf of your
company ? Can you clarify your position regarding this (From: vs
Copyright) ?

More comments below.

> ---
>  drivers/clocksource/timer-atcpit100.c | 199 ++++++++++++++++++++++++++++++++++
>  1 file changed, 199 insertions(+)
>  create mode 100644 drivers/clocksource/timer-atcpit100.c
> 
> diff --git a/drivers/clocksource/timer-atcpit100.c b/drivers/clocksource/timer-atcpit100.c
> new file mode 100644
> index 0000000..1a5538b
> --- /dev/null
> +++ b/drivers/clocksource/timer-atcpit100.c
> @@ -0,0 +1,199 @@
> +/*
> + *  Andestech ATCPIT100 Timer Device Driver Implementation
> + *
> + *  Copyright (C) 2016 Andes Technology Corporation
> + *
> + * 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.
> + *
> + *
> + */
> +#include <linux/irq.h>
> +#include <linux/clocksource.h>
> +#include <linux/clockchips.h>
> +#include <linux/interrupt.h>
> +#include <linux/ioport.h>
> +#include <linux/cpufreq.h>
> +#include <linux/sched.h>
> +#include <linux/sched_clock.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_platform.h>
> +
> +void __iomem *base;

static

> +static u32 freq;

Please encapsulate in a structure.

With the timer_of API that will be already handled (see the init
function comment).

> +/*
> + * Definition of register offsets
> + */
> +
> +/* ID and Revision Register */
> +#define ID_REV		0x0
> +
> +/* Configuration Register */
> +#define CFG		0x10
> +
> +/* Interrupt Enable Register */
> +#define INT_EN		0x14
> +#define CH_INT_EN(c, i)	((1<<i)<<(4*c))
> +
> +/* Interrupt Status Register */
> +#define INT_STA		0x18
> +#define CH_INT_STA(c, i)	((1<<i)<<(4*c))
> +
> +/* Channel Enable Register */
> +#define CH_EN		0x1C
> +#define CH_TMR_EN(c, t)	((1<<t)<<(4*c))

Why are you redefining 3 times the same macro?

Pre-compute the results as you are only using channel 0 (and channel 1)
and these are in the hot path.


> +/* Ch n Control REgister */
> +#define CH_CTL(n)	(0x20+0x10*n)

Pre-compute.

> +/* Channel clock source , bit 3 , 0:External clock , 1:APB clock */
> +#define APB_CLK		(1<<3)

BIT(3)

> +/* Channel mode , bit 0~2 */
> +#define TMR_32		1
> +#define TMR_16		2
> +#define TMR_8		3

nit: usually use 0x1, 0x2, 0x3

> +#define PWM		4

Remove all PWM related, that ends up in drivers/pwm

> +#define CH_REL(n)	(0x24+0x10*n)
> +#define CH_CNT(n)	(0x28+0x10*n)

Pre-compute.

> +static unsigned long atcpit100_read_current_timer_down(void)
> +{
> +	return ~readl(base + CH_CNT(1));
> +}
> +
> +static u64 notrace atcpit100_read_sched_clock_down(void)
> +{
> +	return atcpit100_read_current_timer_down();
> +}
> +
> +static void atcpit100_clocksource_init(void)
> +{
> +	writel(0xffffffff, base + CH_REL(1));
> +	writel(APB_CLK|TMR_32, base + CH_CTL(1));
> +	writel(readl(base + CH_EN) | CH_TMR_EN(1, 0), base + CH_EN);

Wrap these calls into properly named functions:

eg. atcpit100_timer_disable(), atcpit100_timer_enable()



> +	clocksource_mmio_init(base + CH_CNT(1),
> +			      "atcpit100_tm1",
> +			      freq,
> +			      300, 32, clocksource_mmio_readl_down);
> +	sched_clock_register(atcpit100_read_sched_clock_down, 32, freq);
> +}
> +
> +static int atcpit100_set_next_event(unsigned long cycles,
> +		struct clock_event_device *evt)
> +{
> +	writel(cycles, base + CH_REL(0));
> +
> +	return 0;
> +}
> +
> +static int atcpit100_set_state_shutdown(struct clock_event_device *evt)
> +{
> +	writel(readl(base + CH_EN) & ~CH_TMR_EN(0, 0), base + CH_EN);
> +
> +	return 0;
> +}
> +static int atcpit100_set_state_periodic(struct clock_event_device *evt)
> +{
> +	writel(freq / HZ - 1, base + CH_CNT(0));
> +	writel(freq / HZ - 1, base + CH_REL(0));
> +	writel(readl(base + CH_EN) | CH_TMR_EN(0, 0), base + CH_EN);
> +
> +	return 0;
> +}
> +static int atcpit100_tick_resume(struct clock_event_device *evt)
> +{
> +	writel(readl(base + INT_STA) | CH_INT_STA(0, 0), base + INT_STA);
> +	writel(readl(base + CH_EN) | CH_TMR_EN(0, 0), base + CH_EN);
> +
> +	return 0;
> +}
> +static int atcpit100_set_state_oneshot(struct clock_event_device *evt)
> +{
> +	writel(0xffffffff, base + CH_REL(0));
> +	writel(readl(base + CH_EN) | CH_TMR_EN(0, 0), base + CH_EN);
> +
> +	return 0;
> +}
> +
> +static struct clock_event_device clockevent_atcpit100 = {
> +	.name		= "atcpit100_tm0",
> +	.features       = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
> +	.shift		= 32,
> +	.cpumask	= cpu_all_mask,
> +	.set_next_event	= atcpit100_set_next_event,
> +	.set_state_shutdown = atcpit100_set_state_shutdown,
> +	.set_state_periodic = atcpit100_set_state_periodic,
> +	.set_state_oneshot = atcpit100_set_state_oneshot,
> +	.tick_resume = atcpit100_tick_resume,
> +};
> +
> +static irqreturn_t timer1_interrupt(int irq, void *dev_id)
> +{
> +	struct clock_event_device *evt = dev_id;
> +
> +	writel(readl(base + INT_STA) | CH_INT_STA(0, 0), base + INT_STA);
> +
> +	evt->event_handler(evt);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static struct irqaction timer1_irq = {
> +	.name		= "Timer Tick",
> +	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
> +	.handler	= timer1_interrupt,
> +	.dev_id		= &clockevent_atcpit100
> +};
> +
> +static void __init atcpit100_clockevent_init(int irq)
> +{
> +	struct clock_event_device *evt = &clockevent_atcpit100;
> +
> +	evt->mult = div_sc(freq, NSEC_PER_SEC, evt->shift);
> +	evt->max_delta_ns = clockevent_delta2ns(0xffffffff, evt);
> +	evt->min_delta_ns = clockevent_delta2ns(3, evt);
> +	clockevents_register_device(evt);
> +	setup_irq(irq, &timer1_irq);> +}
> +
> +static int __init atcpit100_init(struct device_node *dev)
> +{
> +	int irq;
> +
> +	base = of_iomap(dev, 0);
> +	if (!base) {
> +		pr_warn("Can't remap registers");
> +		return -ENXIO;
> +	}
> +
> +	if (of_property_read_u32(dev, "clock-frequency", &freq)) {
> +		pr_warn("Can't read clock-frequency");
> +		return -EINVAL;
> +	}
> +	irq = irq_of_parse_and_map(dev, 0);
> +
> +	if (irq <= 0) {
> +		pr_warn("Failed to map timer IRQ\n");
> +		return -EINVAL;
> +	}

Please, use the timer-of API.

eg:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clocksource/sun4i_timer.c#n143

> +	pr_info("ATCPIT100 timer 1 installed on IRQ %d, with clock %d at %d HZ. in %p\n",
> +			irq, freq, HZ, base);
> +	writel(APB_CLK|TMR_32, base + CH_CTL(0));
> +	writel(readl(base + INT_EN) | CH_INT_EN(0, 0), base + INT_EN);
> +	writel(readl(base + CH_EN) | CH_TMR_EN(0, 0), base + CH_EN);

Same comment as above, wrap these calls.

> +	atcpit100_clocksource_init();
> +	atcpit100_clockevent_init(irq);
> +
> +	return 0;
> +}
> +
> +TIMER_OF_DECLARE(atcpit100, "andestech,atcpit100", atcpit100_init);


Thanks

  -- Daniel


-- 
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[PATCH v3 2/3] clocksource/drivers/Kconfig: Support andestech atcpit100 timer

[Rick Chen]

Add CLKSRC_ATCPIT100 for Andestech atcpit100 timer selection.
It often be used in Andestech AE3XX platform.

Signed-off-by: Rick Chen <rickchen36@gmail.com>
Signed-off-by: Greentime Hu <green.hu@gmail.com>
---
 drivers/clocksource/Kconfig  | 6 ++++++
 drivers/clocksource/Makefile | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index cc60620..e950066 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -615,4 +615,10 @@ config CLKSRC_ST_LPC
 	  Enable this option to use the Low Power controller timer
 	  as clocksource.

+config CLKSRC_ATCPIT100
+	bool "Clocksource for AE3XX platform" if COMPILE_TEST
+  depends on GENERIC_CLOCKEVENTS && HAS_IOMEM
+	help
+	  This option enables support for the Andestech AE3XX platform timers.
+
 endmenu
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index dbc1ad1..24d15bd 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -74,3 +74,4 @@ obj-$(CONFIG_H8300_TMR16)		+= h8300_timer16.o
 obj-$(CONFIG_H8300_TPU)			+= h8300_tpu.o
 obj-$(CONFIG_CLKSRC_ST_LPC)		+= clksrc_st_lpc.o
 obj-$(CONFIG_X86_NUMACHIP)		+= numachip.o
+obj-$(CONFIG_CLKSRC_ATCPIT100)		+= timer-atcpit100.o
-- 
2.7.4

[PATCH v3 3/3] dt-bindings: timer: Add andestech atcpit100 timer binding doc

[Rick Chen]

Add a document to describe Andestech atcpit100 timer and
binding information.

Signed-off-by: Rick Chen <rickchen36@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greentime Hu <green.hu@gmail.com>
---
 .../bindings/timer/andestech,atcpit100-timer.txt   | 31 ++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/timer/andestech,atcpit100-timer.txt

diff --git a/Documentation/devicetree/bindings/timer/andestech,atcpit100-timer.txt b/Documentation/devicetree/bindings/timer/andestech,atcpit100-timer.txt
new file mode 100644
index 0000000..a87278a
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/andestech,atcpit100-timer.txt
@@ -0,0 +1,31 @@
+Andestech ATCPIT100 timer
+------------------------------------------------------------------
+ATCPIT100 is a generic IP block from Andes Technology, embedded in
+Andestech AE3XX platforms and other designs.
+
+This timer is a set of compact multi-function timers, which can be
+used as pulse width modulators (PWM) as well as simple timers.
+
+It supports up to 4 PIT channels. Each PIT channel is a
+multi-function timer and provide the following usage scenarios:
+One 32-bit timer
+Two 16-bit timers
+Four 8-bit timers
+One 16-bit PWM
+One 16-bit timer and one 8-bit PWM
+Two 8-bit timer and one 8-bit PWM
+
+Required properties:
+- compatible	: Should be "andestech,atcpit100"
+- reg		: Address and length of the register set
+- interrupts	: Reference to the timer interrupt
+- clock-frequency : The rate in HZ in input of the Andestech ATCPIT100 timer
+
+Examples:
+
+timer0: timer@f0400000 {
+	compatible = "andestech,atcpit100";
+	reg = <0xf0400000 0x1000>;
+	interrupts = <2 4>;
+	clock-frequency = <30000000>;
+};
-- 
2.7.4

Re: [PATCH v3 0/3] *** Fix warning from kbuild test robot ***

[Daniel Lezcano]

On 07/11/2017 08:19, Rick Chen wrote:
> *** Fix warnings when make with ARCH=x86_64 from auto build test ***
> 
> rick (3):
>   clocksource/drivers/atcpit100: Add andestech atcpit100 timer
>   clocksource/drivers/Kconfig: Support andestech atcpit100 timer
>   dt-bindings: timer: Add andestech atcpit100 timer binding doc
> 
>  .../bindings/timer/andestech,atcpit100-timer.txt   |  31 ++++
>  drivers/clocksource/Kconfig                        |   6 +
>  drivers/clocksource/Makefile                       |   1 +
>  drivers/clocksource/timer-atcpit100.c              | 199 +++++++++++++++++++++
>  4 files changed, 237 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/timer/andestech,atcpit100-timer.txt
>  create mode 100644 drivers/clocksource/timer-atcpit100.c

Hi Rick,

I'm not sure to get the 0/3 subject and description.

Is that a changelog ?


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