[PATCH v4 0/4] clocksource/drivers/timer-of/renesas-ostm improvements

[PATCH v4 0/4] clocksource/drivers/timer-of/renesas-ostm improvements

[Geert Uytterhoeven]

	Hi Daniel, Thomas,

This patch series converts the Renesas OSTM driver to the timer-of
framework, and makes device names unique.

Changes compared to v3 ("[PATCH v3 0/3] clocksource/drivers/ostm:
Miscellaneous improvements",
https://lore.kernel.org/lkml/20190807084635.24173-1-geert+renesas@glider.be/):
  - Dropped applied [PATCH 1/3],
  - Dropped obsolete [PATCH 2/3],
  - Convert to timer_of as requested by Daniel,
  - Add new timer-of improvements.

Thanks!

Geert Uytterhoeven (4):
  clocksource/drivers/timer-of: Convert last full_name to %pOF
  clocksource/drivers/timer-of: Use unique device name instead of timer
  clocksource/drivers/renesas-ostm: Convert to timer_of
  clocksource/drivers/renesas-ostm: Use unique device name instead of
    ostm

 drivers/clocksource/Kconfig        |   1 +
 drivers/clocksource/renesas-ostm.c | 189 +++++++++++------------------
 drivers/clocksource/timer-of.c     |   6 +-
 3 files changed, 76 insertions(+), 120 deletions(-)

-- 
2.17.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

[PATCH v4 1/4] clocksource/drivers/timer-of: Convert last full_name to %pOF

[Geert Uytterhoeven]

Commit 469869d18a886e04 ("clocksource: Convert to using %pOF instead of
full_name") converted all but the one just added before by commit
32f2fea6e77e64cd ("clocksource/drivers/timer-of: Handle
of_irq_get_byname() result correctly").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v4:
  - New.
---
 drivers/clocksource/timer-of.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
index 11ff701ff4bb9907..92cfb160657b81e2 100644
--- a/drivers/clocksource/timer-of.c
+++ b/drivers/clocksource/timer-of.c
@@ -57,8 +57,8 @@ static __init int timer_of_irq_init(struct device_node *np,
 	if (of_irq->name) {
 		of_irq->irq = ret = of_irq_get_byname(np, of_irq->name);
 		if (ret < 0) {
-			pr_err("Failed to get interrupt %s for %s\n",
-			       of_irq->name, np->full_name);
+			pr_err("Failed to get interrupt %s for %pOF\n",
+			       of_irq->name, np);
 			return ret;
 		}
 	} else	{
-- 
2.17.1

[PATCH v4 2/4] clocksource/drivers/timer-of: Use unique device name instead of timer

[Geert Uytterhoeven]

If a hardware-specific driver does not provide a name, the timer-of core
falls back to device_node.name.  Due to generic DT node naming policies,
that name is almost always "timer", and thus doesn't identify the actual
timer used.

Fix this by using device_node.full_name instead, which includes the unit
addrees.

Example impact on /proc/timer_list:

    -Clock Event Device: timer
    +Clock Event Device: timer@fcfec400

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v4:
  - New.
---
 drivers/clocksource/timer-of.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
index 92cfb160657b81e2..572da477c6d35c5e 100644
--- a/drivers/clocksource/timer-of.c
+++ b/drivers/clocksource/timer-of.c
@@ -192,7 +192,7 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
 	}
 
 	if (!to->clkevt.name)
-		to->clkevt.name = np->name;
+		to->clkevt.name = np->full_name;
 
 	to->np = np;
 
-- 
2.17.1

[PATCH v4 3/4] clocksource/drivers/renesas-ostm: Convert to timer_of

[Geert Uytterhoeven]

Convert the Renesas OSTM driver to use the timer_of framework.
This reduces the driver object size by 367 bytes (with gcc 7.4.0).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v4:
  - New.

As ARCH_MULTIPLATFORM selects TIMER_OF, timer-of.o was already included,
and thus this conversion does not come with the additional cost of
including timer-of.o:

   text	   data	    bss	    dec	    hex	filename
   1081	      0	      0	   1081	    439	drivers/clocksource/timer-of.o

However, on RZ/A SoCs, timer-of.o was unused before, so this does incur
a theoretical size increase...

Note that the OSTM driver needs TIMER_PROBE (selected by TIMER_OF)
regardless, as it relies on TIMER_OF_DECLARE().
---
 drivers/clocksource/Kconfig        |   1 +
 drivers/clocksource/renesas-ostm.c | 189 +++++++++++------------------
 2 files changed, 73 insertions(+), 117 deletions(-)

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index f35a53ce8988a80c..5fdd76cb1768117e 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -528,6 +528,7 @@ config SH_TIMER_MTU2
 config RENESAS_OSTM
 	bool "Renesas OSTM timer driver" if COMPILE_TEST
 	select CLKSRC_MMIO
+	select TIMER_OF
 	help
 	  Enables the support for the Renesas OSTM.
 
diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c
index 37c39b901bb12b38..46012d905604bc43 100644
--- a/drivers/clocksource/renesas-ostm.c
+++ b/drivers/clocksource/renesas-ostm.c
@@ -6,14 +6,14 @@
  * Copyright (C) 2017 Chris Brandt
  */
 
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
 #include <linux/clk.h>
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/sched_clock.h>
 #include <linux/slab.h>
 
+#include "timer-of.h"
+
 /*
  * The OSTM contains independent channels.
  * The first OSTM channel probed will be set up as a free running
@@ -24,12 +24,6 @@
  * driven clock event.
  */
 
-struct ostm_device {
-	void __iomem *base;
-	unsigned long ticks_per_jiffy;
-	struct clock_event_device ced;
-};
-
 static void __iomem *system_clock;	/* For sched_clock() */
 
 /* OSTM REGISTERS */
@@ -47,41 +41,32 @@ static void __iomem *system_clock;	/* For sched_clock() */
 #define	CTL_ONESHOT		0x02
 #define	CTL_FREERUN		0x02
 
-static struct ostm_device *ced_to_ostm(struct clock_event_device *ced)
-{
-	return container_of(ced, struct ostm_device, ced);
-}
-
-static void ostm_timer_stop(struct ostm_device *ostm)
+static void ostm_timer_stop(struct timer_of *to)
 {
-	if (readb(ostm->base + OSTM_TE) & TE) {
-		writeb(TT, ostm->base + OSTM_TT);
+	if (readb(timer_of_base(to) + OSTM_TE) & TE) {
+		writeb(TT, timer_of_base(to) + OSTM_TT);
 
 		/*
 		 * Read back the register simply to confirm the write operation
 		 * has completed since I/O writes can sometimes get queued by
 		 * the bus architecture.
 		 */
-		while (readb(ostm->base + OSTM_TE) & TE)
+		while (readb(timer_of_base(to) + OSTM_TE) & TE)
 			;
 	}
 }
 
-static int __init ostm_init_clksrc(struct ostm_device *ostm, unsigned long rate)
+static int __init ostm_init_clksrc(struct timer_of *to)
 {
-	/*
-	 * irq not used (clock sources don't use interrupts)
-	 */
-
-	ostm_timer_stop(ostm);
+	ostm_timer_stop(to);
 
-	writel(0, ostm->base + OSTM_CMP);
-	writeb(CTL_FREERUN, ostm->base + OSTM_CTL);
-	writeb(TS, ostm->base + OSTM_TS);
+	writel(0, timer_of_base(to) + OSTM_CMP);
+	writeb(CTL_FREERUN, timer_of_base(to) + OSTM_CTL);
+	writeb(TS, timer_of_base(to) + OSTM_TS);
 
-	return clocksource_mmio_init(ostm->base + OSTM_CNT,
-			"ostm", rate,
-			300, 32, clocksource_mmio_readl_up);
+	return clocksource_mmio_init(timer_of_base(to) + OSTM_CNT, "ostm",
+				     timer_of_rate(to), 300, 32,
+				     clocksource_mmio_readl_up);
 }
 
 static u64 notrace ostm_read_sched_clock(void)
@@ -89,87 +74,75 @@ static u64 notrace ostm_read_sched_clock(void)
 	return readl(system_clock);
 }
 
-static void __init ostm_init_sched_clock(struct ostm_device *ostm,
-			unsigned long rate)
+static void __init ostm_init_sched_clock(struct timer_of *to)
 {
-	system_clock = ostm->base + OSTM_CNT;
-	sched_clock_register(ostm_read_sched_clock, 32, rate);
+	system_clock = timer_of_base(to) + OSTM_CNT;
+	sched_clock_register(ostm_read_sched_clock, 32, timer_of_rate(to));
 }
 
 static int ostm_clock_event_next(unsigned long delta,
-				     struct clock_event_device *ced)
+				 struct clock_event_device *ced)
 {
-	struct ostm_device *ostm = ced_to_ostm(ced);
+	struct timer_of *to = to_timer_of(ced);
 
-	ostm_timer_stop(ostm);
+	ostm_timer_stop(to);
 
-	writel(delta, ostm->base + OSTM_CMP);
-	writeb(CTL_ONESHOT, ostm->base + OSTM_CTL);
-	writeb(TS, ostm->base + OSTM_TS);
+	writel(delta, timer_of_base(to) + OSTM_CMP);
+	writeb(CTL_ONESHOT, timer_of_base(to) + OSTM_CTL);
+	writeb(TS, timer_of_base(to) + OSTM_TS);
 
 	return 0;
 }
 
 static int ostm_shutdown(struct clock_event_device *ced)
 {
-	struct ostm_device *ostm = ced_to_ostm(ced);
+	struct timer_of *to = to_timer_of(ced);
 
-	ostm_timer_stop(ostm);
+	ostm_timer_stop(to);
 
 	return 0;
 }
 static int ostm_set_periodic(struct clock_event_device *ced)
 {
-	struct ostm_device *ostm = ced_to_ostm(ced);
+	struct timer_of *to = to_timer_of(ced);
 
 	if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
-		ostm_timer_stop(ostm);
+		ostm_timer_stop(to);
 
-	writel(ostm->ticks_per_jiffy - 1, ostm->base + OSTM_CMP);
-	writeb(CTL_PERIODIC, ostm->base + OSTM_CTL);
-	writeb(TS, ostm->base + OSTM_TS);
+	writel(timer_of_period(to) - 1, timer_of_base(to) + OSTM_CMP);
+	writeb(CTL_PERIODIC, timer_of_base(to) + OSTM_CTL);
+	writeb(TS, timer_of_base(to) + OSTM_TS);
 
 	return 0;
 }
 
 static int ostm_set_oneshot(struct clock_event_device *ced)
 {
-	struct ostm_device *ostm = ced_to_ostm(ced);
+	struct timer_of *to = to_timer_of(ced);
 
-	ostm_timer_stop(ostm);
+	ostm_timer_stop(to);
 
 	return 0;
 }
 
 static irqreturn_t ostm_timer_interrupt(int irq, void *dev_id)
 {
-	struct ostm_device *ostm = dev_id;
+	struct clock_event_device *ced = dev_id;
 
-	if (clockevent_state_oneshot(&ostm->ced))
-		ostm_timer_stop(ostm);
+	if (clockevent_state_oneshot(ced))
+		ostm_timer_stop(to_timer_of(ced));
 
 	/* notify clockevent layer */
-	if (ostm->ced.event_handler)
-		ostm->ced.event_handler(&ostm->ced);
+	if (ced->event_handler)
+		ced->event_handler(ced);
 
 	return IRQ_HANDLED;
 }
 
-static int __init ostm_init_clkevt(struct ostm_device *ostm, int irq,
-			unsigned long rate)
+static int __init ostm_init_clkevt(struct timer_of *to)
 {
-	struct clock_event_device *ced = &ostm->ced;
-	int ret = -ENXIO;
-
-	ret = request_irq(irq, ostm_timer_interrupt,
-			  IRQF_TIMER | IRQF_IRQPOLL,
-			  "ostm", ostm);
-	if (ret) {
-		pr_err("ostm: failed to request irq\n");
-		return ret;
-	}
+	struct clock_event_device *ced = &to->clkevt;
 
-	ced->name = "ostm";
 	ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC;
 	ced->set_state_shutdown = ostm_shutdown;
 	ced->set_state_periodic = ostm_set_periodic;
@@ -178,79 +151,61 @@ static int __init ostm_init_clkevt(struct ostm_device *ostm, int irq,
 	ced->shift = 32;
 	ced->rating = 300;
 	ced->cpumask = cpumask_of(0);
-	clockevents_config_and_register(ced, rate, 0xf, 0xffffffff);
+	clockevents_config_and_register(ced, timer_of_rate(to), 0xf,
+					0xffffffff);
 
 	return 0;
 }
 
 static int __init ostm_init(struct device_node *np)
 {
-	struct ostm_device *ostm;
-	int ret = -EFAULT;
-	struct clk *ostm_clk = NULL;
-	int irq;
-	unsigned long rate;
-
-	ostm = kzalloc(sizeof(*ostm), GFP_KERNEL);
-	if (!ostm)
-		return -ENOMEM;
-
-	ostm->base = of_iomap(np, 0);
-	if (!ostm->base) {
-		pr_err("ostm: failed to remap I/O memory\n");
-		goto err;
-	}
-
-	irq = irq_of_parse_and_map(np, 0);
-	if (irq < 0) {
-		pr_err("ostm: Failed to get irq\n");
-		goto err;
-	}
+	struct timer_of *to;
+	int ret;
 
-	ostm_clk = of_clk_get(np, 0);
-	if (IS_ERR(ostm_clk)) {
-		pr_err("ostm: Failed to get clock\n");
-		ostm_clk = NULL;
-		goto err;
-	}
+	to = kzalloc(sizeof(*to), GFP_KERNEL);
+	if (!to)
+		return -ENOMEM;
 
-	ret = clk_prepare_enable(ostm_clk);
-	if (ret) {
-		pr_err("ostm: Failed to enable clock\n");
-		goto err;
+	to->flags = TIMER_OF_BASE | TIMER_OF_CLOCK;
+	if (system_clock) {
+		/*
+		 * clock sources don't use interrupts, clock events do
+		 */
+		to->flags |= TIMER_OF_IRQ;
+		to->of_irq.flags = IRQF_TIMER | IRQF_IRQPOLL;
+		to->of_irq.handler = ostm_timer_interrupt;
 	}
 
-	rate = clk_get_rate(ostm_clk);
-	ostm->ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
+	ret = timer_of_init(np, to);
+	if (ret)
+		goto err_free;
 
 	/*
 	 * First probed device will be used as system clocksource. Any
 	 * additional devices will be used as clock events.
 	 */
 	if (!system_clock) {
-		ret = ostm_init_clksrc(ostm, rate);
-
-		if (!ret) {
-			ostm_init_sched_clock(ostm, rate);
-			pr_info("ostm: used for clocksource\n");
-		}
+		ret = ostm_init_clksrc(to);
+		if (ret)
+			goto err_cleanup;
 
+		ostm_init_sched_clock(to);
+		pr_info("ostm: used for clocksource\n");
 	} else {
-		ret = ostm_init_clkevt(ostm, irq, rate);
+		ret = ostm_init_clkevt(to);
+		if (ret)
+			goto err_cleanup;
 
-		if (!ret)
-			pr_info("ostm: used for clock events\n");
-	}
-
-err:
-	if (ret) {
-		clk_disable_unprepare(ostm_clk);
-		iounmap(ostm->base);
-		kfree(ostm);
-		return ret;
+		pr_info("ostm: used for clock events\n");
 	}
 
 	return 0;
+
+err_cleanup:
+	timer_of_cleanup(to);
+err_free:
+	kfree(to);
+	return ret;
 }
 
 TIMER_OF_DECLARE(ostm, "renesas,ostm", ostm_init);
-- 
2.17.1

[PATCH v4 4/4] clocksource/drivers/renesas-ostm: Use unique device name instead of ostm

[Geert Uytterhoeven]

Currently all OSTM devices are called "ostm", also in kernel messages.

As there can be multiple instances in an SoC, this can confuse the user.
Hence construct a unique name from the DT node name, like is done for
platform devices.

On RSK+RZA1, the boot log changes like:

    -clocksource: ostm: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 57352151442 ns
    +clocksource: timer@fcfec000: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 57352151442 ns
     sched_clock: 32 bits at 33MHz, resolution 30ns, wraps every 64440619504ns
    -ostm: used for clocksource
    -ostm: used for clock events
    +/soc/timer@fcfec000: used for clocksource
    +/soc/timer@fcfec400: used for clock events
     ...
    -clocksource: Switched to clocksource ostm
    +clocksource: Switched to clocksource timer@fcfec000

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v4:
  - Rebase on top of timer_of conversion, and use np->full_name or %pOF,
    like the timer-of core does,

v3:
  - Make the name format similar to the one used for platform devices,
  - Use kasprintf() instead of buffer size guessing,
  - Use a real example from rskrza1.

v2 (by Jacopo):
  - Use np->fullname.
---
 drivers/clocksource/renesas-ostm.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c
index 46012d905604bc43..3d06ba66008c7029 100644
--- a/drivers/clocksource/renesas-ostm.c
+++ b/drivers/clocksource/renesas-ostm.c
@@ -64,9 +64,9 @@ static int __init ostm_init_clksrc(struct timer_of *to)
 	writeb(CTL_FREERUN, timer_of_base(to) + OSTM_CTL);
 	writeb(TS, timer_of_base(to) + OSTM_TS);
 
-	return clocksource_mmio_init(timer_of_base(to) + OSTM_CNT, "ostm",
-				     timer_of_rate(to), 300, 32,
-				     clocksource_mmio_readl_up);
+	return clocksource_mmio_init(timer_of_base(to) + OSTM_CNT,
+				     to->np->full_name, timer_of_rate(to), 300,
+				     32, clocksource_mmio_readl_up);
 }
 
 static u64 notrace ostm_read_sched_clock(void)
@@ -190,13 +190,13 @@ static int __init ostm_init(struct device_node *np)
 			goto err_cleanup;
 
 		ostm_init_sched_clock(to);
-		pr_info("ostm: used for clocksource\n");
+		pr_info("%pOF: used for clocksource\n", np);
 	} else {
 		ret = ostm_init_clkevt(to);
 		if (ret)
 			goto err_cleanup;
 
-		pr_info("ostm: used for clock events\n");
+		pr_info("%pOF: used for clock events\n", np);
 	}
 
 	return 0;
-- 
2.17.1

Re: [PATCH v4 2/4] clocksource/drivers/timer-of: Use unique device name instead of timer

[Rob Herring]

On Wed, Oct 16, 2019 at 9:52 AM Geert Uytterhoeven
<geert+renesas@glider.be> wrote:
>
> If a hardware-specific driver does not provide a name, the timer-of core
> falls back to device_node.name.  Due to generic DT node naming policies,
> that name is almost always "timer", and thus doesn't identify the actual
> timer used.
>
> Fix this by using device_node.full_name instead, which includes the unit
> addrees.
>
> Example impact on /proc/timer_list:
>
>     -Clock Event Device: timer
>     +Clock Event Device: timer@fcfec400
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> v4:
>   - New.
> ---
>  drivers/clocksource/timer-of.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Good. One less device_node.name pointer use to get rid of. I want to
drop it from the struct and stop storing both node name strings.

Reviewed-by: Rob Herring <robh@kernel.org>

Rob

Re: [PATCH v4 0/4] clocksource/drivers/timer-of/renesas-ostm improvements

[Daniel Lezcano]

On 16/10/2019 16:47, Geert Uytterhoeven wrote:
> 	Hi Daniel, Thomas,
> 
> This patch series converts the Renesas OSTM driver to the timer-of
> framework, and makes device names unique.
> 
> Changes compared to v3 ("[PATCH v3 0/3] clocksource/drivers/ostm:
> Miscellaneous improvements",
> https://lore.kernel.org/lkml/20190807084635.24173-1-geert+renesas@glider.be/):
>   - Dropped applied [PATCH 1/3],
>   - Dropped obsolete [PATCH 2/3],
>   - Convert to timer_of as requested by Daniel,
>   - Add new timer-of improvements.

Applied, thanks!


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