[PATCH v3 0/6] clocksource/drivers/timer-microchip-pit64b: fixes and improvements

[PATCH v3 0/6] clocksource/drivers/timer-microchip-pit64b: fixes and improvements

[Claudiu Beznea]

Hi,

The series adds one fix and few improvement for PIT64B timer. Patch 1/7
was initially posted at [1].

Thank you,
Claudiu Beznea

[1] https://lore.kernel.org/lkml/20210707054415.92832-1-claudiu.beznea@microchip.com/

Changes in v3:
- removed patch "clocksource/drivers/timer-microchip-pit64b: remove timer-of depenency"
  as it breaks build on other platforms
- adapt patch 6/6 to comply with kernel-doc specification

Changes in v2:
- removed patch 5/7 "clocksource/drivers/timer-microchip-pit64b: add delay timer"
  to avoid compilation errors on non ARM platforms; will re-introduce it after
  a bit of rework on AT91 specific Kconfig
- added patch "clocksource/drivers/timer-microchip-pit64b: fix compilation warnings"
- in patch "clocksource/drivers/timer-microchip-pit64b: use mchp_pit64b_{suspend,
  resume}" remove gclk_unprepare, pclk_unprepare labels and code under them


Claudiu Beznea (6):
  clocksource/drivers/timer-microchip-pit64b: remove mmio selection
  clocksource/drivers/timer-microchip-pit64b: use notrace
  clocksource/drivers/timer-microchip-pit64b: use 5MHz for clockevent
  clocksource/drivers/timer-microchip-pit64b: remove suspend/resume ops
    for ce
  clocksource/drivers/timer-microchip-pit64b: use mchp_pit64b_{suspend,
    resume}
  clocksource/drivers/timer-microchip-pit64b: fix compilation warnings

 drivers/clocksource/Kconfig                  |  1 -
 drivers/clocksource/timer-microchip-pit64b.c | 72 ++++++++------------
 2 files changed, 30 insertions(+), 43 deletions(-)

-- 
2.32.0


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

[PATCH v3 1/6] clocksource/drivers/timer-microchip-pit64b: remove mmio selection

[Claudiu Beznea]

PIT64B timer driver doesn't depend on CLKSRC_MMIO since
commit e85c1d21b16b ("clocksource/drivers/timer-microchip-pit64b:
Add clocksource suspend/resume"). Remove the selection.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/clocksource/Kconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index cfb8ea0df3b1..1ea556e75494 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -713,7 +713,6 @@ config INGENIC_OST
 config MICROCHIP_PIT64B
 	bool "Microchip PIT64B support"
 	depends on OF || COMPILE_TEST
-	select CLKSRC_MMIO
 	select TIMER_OF
 	help
 	  This option enables Microchip PIT64B timer for Atmel
-- 
2.32.0


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

[PATCH v3 2/6] clocksource/drivers/timer-microchip-pit64b: use notrace

[Claudiu Beznea]

Use notrace for mchp_pit64b_sched_read_clk() to avoid recursive call of
prepare_ftrace_return() when issuing:
echo function_graph > /sys/kernel/debug/tracing/current_tracer

Fixes: 625022a5f160 ("clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/clocksource/timer-microchip-pit64b.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/timer-microchip-pit64b.c b/drivers/clocksource/timer-microchip-pit64b.c
index cfa4ec7ef396..790d2c9b42a7 100644
--- a/drivers/clocksource/timer-microchip-pit64b.c
+++ b/drivers/clocksource/timer-microchip-pit64b.c
@@ -165,7 +165,7 @@ static u64 mchp_pit64b_clksrc_read(struct clocksource *cs)
 	return mchp_pit64b_cnt_read(mchp_pit64b_cs_base);
 }
 
-static u64 mchp_pit64b_sched_read_clk(void)
+static u64 notrace mchp_pit64b_sched_read_clk(void)
 {
 	return mchp_pit64b_cnt_read(mchp_pit64b_cs_base);
 }
-- 
2.32.0


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

[PATCH v3 3/6] clocksource/drivers/timer-microchip-pit64b: use 5MHz for clockevent

[Claudiu Beznea]

Use 5MHz clock for clockevent timers. This increases timer's
resolution.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/clocksource/timer-microchip-pit64b.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/timer-microchip-pit64b.c b/drivers/clocksource/timer-microchip-pit64b.c
index 790d2c9b42a7..abce83d2f00b 100644
--- a/drivers/clocksource/timer-microchip-pit64b.c
+++ b/drivers/clocksource/timer-microchip-pit64b.c
@@ -42,8 +42,7 @@
 #define MCHP_PIT64B_LSBMASK		GENMASK_ULL(31, 0)
 #define MCHP_PIT64B_PRES_TO_MODE(p)	(MCHP_PIT64B_MR_PRES & ((p) << 8))
 #define MCHP_PIT64B_MODE_TO_PRES(m)	((MCHP_PIT64B_MR_PRES & (m)) >> 8)
-#define MCHP_PIT64B_DEF_CS_FREQ		5000000UL	/* 5 MHz */
-#define MCHP_PIT64B_DEF_CE_FREQ		32768		/* 32 KHz */
+#define MCHP_PIT64B_DEF_FREQ		5000000UL	/* 5 MHz */
 
 #define MCHP_PIT64B_NAME		"pit64b"
 
@@ -418,7 +417,6 @@ static int __init mchp_pit64b_init_clkevt(struct mchp_pit64b_timer *timer,
 static int __init mchp_pit64b_dt_init_timer(struct device_node *node,
 					    bool clkevt)
 {
-	u32 freq = clkevt ? MCHP_PIT64B_DEF_CE_FREQ : MCHP_PIT64B_DEF_CS_FREQ;
 	struct mchp_pit64b_timer timer;
 	unsigned long clk_rate;
 	u32 irq = 0;
@@ -446,7 +444,7 @@ static int __init mchp_pit64b_dt_init_timer(struct device_node *node,
 	}
 
 	/* Initialize mode (prescaler + SGCK bit). To be used at runtime. */
-	ret = mchp_pit64b_init_mode(&timer, freq);
+	ret = mchp_pit64b_init_mode(&timer, MCHP_PIT64B_DEF_FREQ);
 	if (ret)
 		goto irq_unmap;
 
-- 
2.32.0


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

[PATCH v3 4/6] clocksource/drivers/timer-microchip-pit64b: remove suspend/resume ops for ce

[Claudiu Beznea]

Remove suspend and resume ops for clockevent and add set_state_oneshot()
instead. Along with this mchp_pit64b_{suspend, resume}() were called on
proper function to disable/enable clocks. This will allow disabling clocks
for clockevent in case it is not selected as active clockevent.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/clocksource/timer-microchip-pit64b.c | 30 +++++++++++---------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/clocksource/timer-microchip-pit64b.c b/drivers/clocksource/timer-microchip-pit64b.c
index abce83d2f00b..b51259395ac3 100644
--- a/drivers/clocksource/timer-microchip-pit64b.c
+++ b/drivers/clocksource/timer-microchip-pit64b.c
@@ -173,7 +173,8 @@ static int mchp_pit64b_clkevt_shutdown(struct clock_event_device *cedev)
 {
 	struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);
 
-	writel_relaxed(MCHP_PIT64B_CR_SWRST, timer->base + MCHP_PIT64B_CR);
+	if (!clockevent_state_detached(cedev))
+		mchp_pit64b_suspend(timer);
 
 	return 0;
 }
@@ -182,35 +183,37 @@ static int mchp_pit64b_clkevt_set_periodic(struct clock_event_device *cedev)
 {
 	struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);
 
+	if (clockevent_state_shutdown(cedev))
+		mchp_pit64b_resume(timer);
+
 	mchp_pit64b_reset(timer, mchp_pit64b_ce_cycles, MCHP_PIT64B_MR_CONT,
 			  MCHP_PIT64B_IER_PERIOD);
 
 	return 0;
 }
 
-static int mchp_pit64b_clkevt_set_next_event(unsigned long evt,
-					     struct clock_event_device *cedev)
+static int mchp_pit64b_clkevt_set_oneshot(struct clock_event_device *cedev)
 {
 	struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);
 
-	mchp_pit64b_reset(timer, evt, MCHP_PIT64B_MR_ONE_SHOT,
+	if (clockevent_state_shutdown(cedev))
+		mchp_pit64b_resume(timer);
+
+	mchp_pit64b_reset(timer, mchp_pit64b_ce_cycles, MCHP_PIT64B_MR_ONE_SHOT,
 			  MCHP_PIT64B_IER_PERIOD);
 
 	return 0;
 }
 
-static void mchp_pit64b_clkevt_suspend(struct clock_event_device *cedev)
+static int mchp_pit64b_clkevt_set_next_event(unsigned long evt,
+					     struct clock_event_device *cedev)
 {
 	struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);
 
-	mchp_pit64b_suspend(timer);
-}
-
-static void mchp_pit64b_clkevt_resume(struct clock_event_device *cedev)
-{
-	struct mchp_pit64b_timer *timer = clkevt_to_mchp_pit64b_timer(cedev);
+	mchp_pit64b_reset(timer, evt, MCHP_PIT64B_MR_ONE_SHOT,
+			  MCHP_PIT64B_IER_PERIOD);
 
-	mchp_pit64b_resume(timer);
+	return 0;
 }
 
 static irqreturn_t mchp_pit64b_interrupt(int irq, void *dev_id)
@@ -395,9 +398,8 @@ static int __init mchp_pit64b_init_clkevt(struct mchp_pit64b_timer *timer,
 	ce->clkevt.rating = 150;
 	ce->clkevt.set_state_shutdown = mchp_pit64b_clkevt_shutdown;
 	ce->clkevt.set_state_periodic = mchp_pit64b_clkevt_set_periodic;
+	ce->clkevt.set_state_oneshot = mchp_pit64b_clkevt_set_oneshot;
 	ce->clkevt.set_next_event = mchp_pit64b_clkevt_set_next_event;
-	ce->clkevt.suspend = mchp_pit64b_clkevt_suspend;
-	ce->clkevt.resume = mchp_pit64b_clkevt_resume;
 	ce->clkevt.cpumask = cpumask_of(0);
 	ce->clkevt.irq = irq;
 
-- 
2.32.0


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

[PATCH v3 5/6] clocksource/drivers/timer-microchip-pit64b: use mchp_pit64b_{suspend, resume}

[Claudiu Beznea]

Use mchp_pit64b_suspend() and mchp_pit64b_resume() to disable or
enable timers clocks on init and remove specific
clk_prepare_{disable, enable} calls. This is ok also for clockevent timer
as proper clock enable, disable is done on .set_state_oneshot,
.set_state_periodic, .set_state_shutdown calls.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/clocksource/timer-microchip-pit64b.c | 24 ++++----------------
 1 file changed, 5 insertions(+), 19 deletions(-)

diff --git a/drivers/clocksource/timer-microchip-pit64b.c b/drivers/clocksource/timer-microchip-pit64b.c
index b51259395ac3..f50705698283 100644
--- a/drivers/clocksource/timer-microchip-pit64b.c
+++ b/drivers/clocksource/timer-microchip-pit64b.c
@@ -344,6 +344,7 @@ static int __init mchp_pit64b_init_clksrc(struct mchp_pit64b_timer *timer,
 	if (!cs)
 		return -ENOMEM;
 
+	mchp_pit64b_resume(timer);
 	mchp_pit64b_reset(timer, ULLONG_MAX, MCHP_PIT64B_MR_CONT, 0);
 
 	mchp_pit64b_cs_base = timer->base;
@@ -365,8 +366,7 @@ static int __init mchp_pit64b_init_clksrc(struct mchp_pit64b_timer *timer,
 		pr_debug("clksrc: Failed to register PIT64B clocksource!\n");
 
 		/* Stop timer. */
-		writel_relaxed(MCHP_PIT64B_CR_SWRST,
-			       timer->base + MCHP_PIT64B_CR);
+		mchp_pit64b_suspend(timer);
 		kfree(cs);
 
 		return ret;
@@ -450,19 +450,10 @@ static int __init mchp_pit64b_dt_init_timer(struct device_node *node,
 	if (ret)
 		goto irq_unmap;
 
-	ret = clk_prepare_enable(timer.pclk);
-	if (ret)
-		goto irq_unmap;
-
-	if (timer.mode & MCHP_PIT64B_MR_SGCLK) {
-		ret = clk_prepare_enable(timer.gclk);
-		if (ret)
-			goto pclk_unprepare;
-
+	if (timer.mode & MCHP_PIT64B_MR_SGCLK)
 		clk_rate = clk_get_rate(timer.gclk);
-	} else {
+	else
 		clk_rate = clk_get_rate(timer.pclk);
-	}
 	clk_rate = clk_rate / (MCHP_PIT64B_MODE_TO_PRES(timer.mode) + 1);
 
 	if (clkevt)
@@ -471,15 +462,10 @@ static int __init mchp_pit64b_dt_init_timer(struct device_node *node,
 		ret = mchp_pit64b_init_clksrc(&timer, clk_rate);
 
 	if (ret)
-		goto gclk_unprepare;
+		goto irq_unmap;
 
 	return 0;
 
-gclk_unprepare:
-	if (timer.mode & MCHP_PIT64B_MR_SGCLK)
-		clk_disable_unprepare(timer.gclk);
-pclk_unprepare:
-	clk_disable_unprepare(timer.pclk);
 irq_unmap:
 	irq_dispose_mapping(irq);
 io_unmap:
-- 
2.32.0


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

[PATCH v3 6/6] clocksource/drivers/timer-microchip-pit64b: fix compilation warnings

[Claudiu Beznea]

Fix the following compilation warnings:
timer-microchip-pit64b.c:68: warning: cannot understand function prototype: 'struct mchp_pit64b_clkevt '
timer-microchip-pit64b.c:82: warning: cannot understand function prototype: 'struct mchp_pit64b_clksrc '
timer-microchip-pit64b.c:283: warning: Function parameter or member 'timer' not described in 'mchp_pit64b_init_mode'
timer-microchip-pit64b.c:283: warning: Function parameter or member 'max_rate' not described in 'mchp_pit64b_init_mode'

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/clocksource/timer-microchip-pit64b.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/timer-microchip-pit64b.c b/drivers/clocksource/timer-microchip-pit64b.c
index f50705698283..d5f1436f33d9 100644
--- a/drivers/clocksource/timer-microchip-pit64b.c
+++ b/drivers/clocksource/timer-microchip-pit64b.c
@@ -61,7 +61,7 @@ struct mchp_pit64b_timer {
 };
 
 /**
- * mchp_pit64b_clkevt - PIT64B clockevent data structure
+ * struct mchp_pit64b_clkevt - PIT64B clockevent data structure
  * @timer: PIT64B timer
  * @clkevt: clockevent
  */
@@ -75,7 +75,7 @@ struct mchp_pit64b_clkevt {
 		struct mchp_pit64b_clkevt, clkevt))
 
 /**
- * mchp_pit64b_clksrc - PIT64B clocksource data structure
+ * struct mchp_pit64b_clksrc - PIT64B clocksource data structure
  * @timer: PIT64B timer
  * @clksrc: clocksource
  */
@@ -245,8 +245,10 @@ static void __init mchp_pit64b_pres_compute(u32 *pres, u32 clk_rate,
 }
 
 /**
- * mchp_pit64b_init_mode - prepare PIT64B mode register value to be used at
- *			   runtime; this includes prescaler and SGCLK bit
+ * mchp_pit64b_init_mode() - prepare PIT64B mode register value to be used at
+ *			     runtime; this includes prescaler and SGCLK bit
+ * @timer: pointer to pit64b timer to init
+ * @max_rate: maximum rate that timer's clock could use
  *
  * PIT64B timer may be fed by gclk or pclk. When gclk is used its rate has to
  * be at least 3 times lower that pclk's rate. pclk rate is fixed, gclk rate
-- 
2.32.0


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

Re: [PATCH v3 0/6] clocksource/drivers/timer-microchip-pit64b: fixes and improvements

[Daniel Lezcano]

Hi Claudiu,

I would like to pick patches 1,2,3 but not the others one because I'm 
not convinced about the suspend / resume changes and need some time to 
think about it.

   -- D.


On 04/03/2022 14:35, Claudiu Beznea wrote:
> Hi,
> 
> The series adds one fix and few improvement for PIT64B timer. Patch 1/7
> was initially posted at [1].
> 
> Thank you,
> Claudiu Beznea
> 
> [1] https://lore.kernel.org/lkml/20210707054415.92832-1-claudiu.beznea@microchip.com/
> 
> Changes in v3:
> - removed patch "clocksource/drivers/timer-microchip-pit64b: remove timer-of depenency"
>    as it breaks build on other platforms
> - adapt patch 6/6 to comply with kernel-doc specification
> 
> Changes in v2:
> - removed patch 5/7 "clocksource/drivers/timer-microchip-pit64b: add delay timer"
>    to avoid compilation errors on non ARM platforms; will re-introduce it after
>    a bit of rework on AT91 specific Kconfig
> - added patch "clocksource/drivers/timer-microchip-pit64b: fix compilation warnings"
> - in patch "clocksource/drivers/timer-microchip-pit64b: use mchp_pit64b_{suspend,
>    resume}" remove gclk_unprepare, pclk_unprepare labels and code under them
> 
> 
> Claudiu Beznea (6):
>    clocksource/drivers/timer-microchip-pit64b: remove mmio selection
>    clocksource/drivers/timer-microchip-pit64b: use notrace
>    clocksource/drivers/timer-microchip-pit64b: use 5MHz for clockevent
>    clocksource/drivers/timer-microchip-pit64b: remove suspend/resume ops
>      for ce
>    clocksource/drivers/timer-microchip-pit64b: use mchp_pit64b_{suspend,
>      resume}
>    clocksource/drivers/timer-microchip-pit64b: fix compilation warnings
> 
>   drivers/clocksource/Kconfig                  |  1 -
>   drivers/clocksource/timer-microchip-pit64b.c | 72 ++++++++------------
>   2 files changed, 30 insertions(+), 43 deletions(-)
> 


-- 
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

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

Re: [PATCH v3 0/6] clocksource/drivers/timer-microchip-pit64b: fixes and improvements

[Claudiu.Beznea]

On 04.03.2022 21:46, Daniel Lezcano wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> Hi Claudiu,
> 
> I would like to pick patches 1,2,3 but not the others one because I'm
> not convinced about the suspend / resume changes and need some time to
> think about it.
Hi Daniel,

Sure!

Just to let you know, I've tested it on suspend/resume scenarios (some of
the scenarios were cutting down the power to PIT64B blocks) and on a system
having both PIT64B and ARM generic timer enabled.

Thank you,
Claudiu Beznea

> 
>   -- D.
> 
> 
> On 04/03/2022 14:35, Claudiu Beznea wrote:
>> Hi,
>>
>> The series adds one fix and few improvement for PIT64B timer. Patch 1/7
>> was initially posted at [1].
>>
>> Thank you,
>> Claudiu Beznea
>>
>> [1]
>> https://lore.kernel.org/lkml/20210707054415.92832-1-claudiu.beznea@microchip.com/
>>
>>
>> Changes in v3:
>> - removed patch "clocksource/drivers/timer-microchip-pit64b: remove
>> timer-of depenency"
>>    as it breaks build on other platforms
>> - adapt patch 6/6 to comply with kernel-doc specification
>>
>> Changes in v2:
>> - removed patch 5/7 "clocksource/drivers/timer-microchip-pit64b: add
>> delay timer"
>>    to avoid compilation errors on non ARM platforms; will re-introduce it
>> after
>>    a bit of rework on AT91 specific Kconfig
>> - added patch "clocksource/drivers/timer-microchip-pit64b: fix
>> compilation warnings"
>> - in patch "clocksource/drivers/timer-microchip-pit64b: use
>> mchp_pit64b_{suspend,
>>    resume}" remove gclk_unprepare, pclk_unprepare labels and code under them
>>
>>
>> Claudiu Beznea (6):
>>    clocksource/drivers/timer-microchip-pit64b: remove mmio selection
>>    clocksource/drivers/timer-microchip-pit64b: use notrace
>>    clocksource/drivers/timer-microchip-pit64b: use 5MHz for clockevent
>>    clocksource/drivers/timer-microchip-pit64b: remove suspend/resume ops
>>      for ce
>>    clocksource/drivers/timer-microchip-pit64b: use mchp_pit64b_{suspend,
>>      resume}
>>    clocksource/drivers/timer-microchip-pit64b: fix compilation warnings
>>
>>   drivers/clocksource/Kconfig                  |  1 -
>>   drivers/clocksource/timer-microchip-pit64b.c | 72 ++++++++------------
>>   2 files changed, 30 insertions(+), 43 deletions(-)
>>
> 
> 
> -- 
> <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
> 
> Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog

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