[PATCH 00/23] ARM: at91: Properly handle slow clock

[PATCH 00/23] ARM: at91: Properly handle slow clock

[Alexandre Belloni]

Hi,

It was discovered that all the slow clock user were not properly claiming it.
This can end up in a system hang because the last registered user is releasing
it, and it gets disabled.

commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system hang")
was a workaround. This series is adding the slow clock to the necessary drivers
to avoid the issue and then removes that workaround.

The Documentation updates and DT patches should probably go through the AT91
tree this cycle to avoid breakage.

Then the other patches can go through each subsystem tree. They are trivial
enough to also go in this cycle.

The final clk patch depends on the other ones and may be taken for the next
cycle to avoid synchronization issues.

I've thrown in a cleanup for at91-reset as it avoids adding support for that
clock to the platform data initialization

Changes in v2:
 - statisticize the global in the atmel-st change
 - merge at91_reset_of_probe() in at91_reset_probe()
 - added patches from Boris for the TCB
 - added the slow clock to the TCB

Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-clk@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-pwm@vger.kernel.org
Cc: linux-watchdog@vger.kernel.org
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: rtc-linux@googlegroups.com
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wim Van Sebroeck <wim@iguana.be>

Alexandre Belloni (20):
  Documentation: dt: atmel-at91: add clocks to system timer, rstc and
    shdwc
  Documentation: watchdog: at91sam9_wdt: add clocks property
  Documentation: dt: rtc: at91rm9200: add clocks property
  ARM: at91/dt: at91rm9200: use slow clock where necessary
  ARM: at91/dt: at91sam9260: use slow clock where necessary
  ARM: at91/dt: at91sam9261: use slow clock where necessary
  ARM: at91/dt: at91sam9263: use slow clock where necessary
  ARM: at91/dt: at91sam9g45: use slow clock where necessary
  ARM: at91/dt: at91sam9n12: use slow clock where necessary
  ARM: at91/dt: at91sam9rl: use slow clock where necessary
  ARM: at91/dt: at91sam9x5: use slow clock where necessary
  ARM: at91/dt: sama5d3: use slow clock where necessary
  ARM: at91/dt: sama5d4: use slow clock where necessary
  rtc: at91rm9200: get and use slow clock
  watchdog: at91sam9: get and use slow clock
  power/reset: at91-reset: remove useless at91_reset_platform_probe()
  power/reset: at91-reset: get and use slow clock
  power/reset: at91-poweroff: get and use slow clock
  clocksource: atmel-st: get and use slow clock
  clk: at91: Revert "keep slow clk enabled to prevent system hang"

Boris Brezillon (3):
  Documentation: dt: atmel-at91: add slow clock to tcb
  clocksource: tcb_clksrc: fix setup_clkevents error path
  misc: atmel_tclib: get and use slow clock

 .../devicetree/bindings/arm/atmel-at91.txt         | 13 +++--
 .../bindings/rtc/atmel,at91rm9200-rtc.txt          |  2 +
 .../devicetree/bindings/watchdog/atmel-wdt.txt     |  2 +
 arch/arm/boot/dts/at91rm9200.dtsi                  | 10 ++--
 arch/arm/boot/dts/at91sam9260.dtsi                 | 11 +++--
 arch/arm/boot/dts/at91sam9261.dtsi                 |  7 ++-
 arch/arm/boot/dts/at91sam9263.dtsi                 |  7 ++-
 arch/arm/boot/dts/at91sam9g45.dtsi                 | 12 +++--
 arch/arm/boot/dts/at91sam9n12.dtsi                 | 12 +++--
 arch/arm/boot/dts/at91sam9rl.dtsi                  |  8 ++-
 arch/arm/boot/dts/at91sam9x5.dtsi                  | 12 +++--
 arch/arm/boot/dts/sama5d3.dtsi                     |  8 ++-
 arch/arm/boot/dts/sama5d3_tcb1.dtsi                |  4 +-
 arch/arm/boot/dts/sama5d4.dtsi                     | 12 +++--
 drivers/clk/at91/clk-slow.c                        | 27 ----------
 drivers/clocksource/tcb_clksrc.c                   | 10 +++-
 drivers/clocksource/timer-atmel-st.c               | 31 ++++++++----
 drivers/misc/atmel_tclib.c                         |  4 ++
 drivers/power/reset/at91-poweroff.c                | 13 +++++
 drivers/power/reset/at91-reset.c                   | 57 ++++++----------------
 drivers/pwm/pwm-atmel-tcb.c                        | 23 ++++++---
 drivers/rtc/rtc-at91rm9200.c                       | 27 ++++++++--
 drivers/watchdog/at91sam9_wdt.c                    | 22 ++++++++-
 include/linux/atmel_tc.h                           |  1 +
 24 files changed, 206 insertions(+), 129 deletions(-)

-- 
2.1.4

[PATCH 01/23] Documentation: dt: atmel-at91: add clocks to system timer, rstc and shdwc

[Alexandre Belloni]

The system timer (at91rm9200), the reset controller and the shutdown
controller need an input clock. This is the slow clock and they will not
function without it.

Also fix the shutdown controller example.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: linux-pm@vger.kernel.org
 Documentation/devicetree/bindings/arm/atmel-at91.txt | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
index 424ac8cbfa08..209710cdf3aa 100644
--- a/Documentation/devicetree/bindings/arm/atmel-at91.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
@@ -50,6 +50,7 @@ System Timer (ST) required properties:
 - reg: Should contain registers location and length
 - interrupts: Should contain interrupt for the ST which is the IRQ line
   shared across all System Controller members.
+- clocks: phandle to input clock.
 Its subnodes can be:
 - watchdog: compatible should be "atmel,at91rm9200-wdt"
 
@@ -89,12 +90,14 @@ RSTC Reset Controller required properties:
 - compatible: Should be "atmel,<chip>-rstc".
   <chip> can be "at91sam9260" or "at91sam9g45"
 - reg: Should contain registers location and length
+- clocks: phandle to input clock.
 
 Example:
 
 	rstc@fffffd00 {
 		compatible = "atmel,at91sam9260-rstc";
 		reg = <0xfffffd00 0x10>;
+		clocks = <&clk32k>;
 	};
 
 RAMC SDRAM/DDR Controller required properties:
@@ -117,6 +120,7 @@ required properties:
 - compatible: Should be "atmel,<chip>-shdwc".
   <chip> can be "at91sam9260", "at91sam9rl" or "at91sam9x5".
 - reg: Should contain registers location and length
+- clocks: phandle to input clock.
 
 optional properties:
 - atmel,wakeup-mode: String, operation mode of the wakeup mode.
@@ -135,9 +139,10 @@ optional at91sam9x5 properties:
 
 Example:
 
-	rstc@fffffd00 {
-		compatible = "atmel,at91sam9260-rstc";
-		reg = <0xfffffd00 0x10>;
+	shdwc@fffffd10 {
+		compatible = "atmel,at91sam9260-shdwc";
+		reg = <0xfffffd10 0x10>;
+		clocks = <&clk32k>;
 	};
 
 Special Function Registers (SFR)
-- 
2.1.4

Re: [PATCH 01/23] Documentation: dt: atmel-at91: add clocks to system timer, rstc and shdwc

[Sebastian Reichel]

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Hi,

On Fri, Jul 31, 2015 at 11:39:37AM +0200, Alexandre Belloni wrote:
> The system timer (at91rm9200), the reset controller and the shutdown
> controller need an input clock. This is the slow clock and they will not
> function without it.
> 
> Also fix the shutdown controller example.

Acked-By: Sebastian Reichel <sre@kernel.org>

-- Sebastian

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[PATCH 17/23] power/reset: at91-reset: remove useless at91_reset_platform_probe()

[Alexandre Belloni]

Since all the at91 platforms are now DT only, at91_reset_platform_probe()
is now useless, remove it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: linux-pm@vger.kernel.or
 drivers/power/reset/at91-reset.c | 47 +++-------------------------------------
 1 file changed, 3 insertions(+), 44 deletions(-)

diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 36dc52fb2ec8..3225c8590ed0 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -169,11 +169,11 @@ static struct notifier_block at91_restart_nb = {
 	.priority = 192,
 };
 
-static int at91_reset_of_probe(struct platform_device *pdev)
+static int at91_reset_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *match;
 	struct device_node *np;
-	int idx = 0;
+	int ret, idx = 0;
 
 	at91_rstc_base = of_iomap(pdev->dev.of_node, 0);
 	if (!at91_rstc_base) {
@@ -192,49 +192,8 @@ static int at91_reset_of_probe(struct platform_device *pdev)
 
 	match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
 	at91_restart_nb.notifier_call = match->data;
-	return register_restart_handler(&at91_restart_nb);
-}
-
-static int at91_reset_platform_probe(struct platform_device *pdev)
-{
-	const struct platform_device_id *match;
-	struct resource *res;
-	int idx = 0;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	at91_rstc_base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(at91_rstc_base)) {
-		dev_err(&pdev->dev, "Could not map reset controller address\n");
-		return PTR_ERR(at91_rstc_base);
-	}
-
-	for (idx = 0; idx < 2; idx++) {
-		res = platform_get_resource(pdev, IORESOURCE_MEM, idx + 1 );
-		at91_ramc_base[idx] = devm_ioremap(&pdev->dev, res->start,
-						   resource_size(res));
-		if (!at91_ramc_base[idx]) {
-			dev_err(&pdev->dev, "Could not map ram controller address\n");
-			return -ENOMEM;
-		}
-	}
-
-	match = platform_get_device_id(pdev);
-	at91_restart_nb.notifier_call =
-		(int (*)(struct notifier_block *,
-			 unsigned long, void *)) match->driver_data;
-
-	return register_restart_handler(&at91_restart_nb);
-}
-
-static int at91_reset_probe(struct platform_device *pdev)
-{
-	int ret;
-
-	if (pdev->dev.of_node)
-		ret = at91_reset_of_probe(pdev);
-	else
-		ret = at91_reset_platform_probe(pdev);
 
+	ret = register_restart_handler(&at91_restart_nb);
 	if (ret)
 		return ret;
 
-- 
2.1.4

[PATCH 18/23] power/reset: at91-reset: get and use slow clock

[Alexandre Belloni]

Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.

Get and use the slow clock as it is necessary for the at91 reset
controller.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: linux-pm@vger.kernel.org
 drivers/power/reset/at91-reset.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 3225c8590ed0..19fdd4c107dc 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -11,6 +11,7 @@
  * warranty of any kind, whether express or implied.
  */
 
+#include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -46,6 +47,7 @@ enum reset_type {
 };
 
 static void __iomem *at91_ramc_base[2], *at91_rstc_base;
+static struct clk *sclk;
 
 /*
 * unless the SDRAM is cleanly shutdown before we hit the
@@ -193,9 +195,21 @@ static int at91_reset_probe(struct platform_device *pdev)
 	match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
 	at91_restart_nb.notifier_call = match->data;
 
+	sclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sclk))
+		return PTR_ERR(sclk);
+
+	ret = clk_prepare_enable(sclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not enable slow clock\n");
+		return ret;
+	}
+
 	ret = register_restart_handler(&at91_restart_nb);
-	if (ret)
+	if (ret) {
+		clk_disable_unprepare(sclk);
 		return ret;
+	}
 
 	at91_reset_status(pdev);
 
-- 
2.1.4

Re: [PATCH 18/23] power/reset: at91-reset: get and use slow clock

[Sebastian Reichel]

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Hi,

On Fri, Jul 31, 2015 at 11:39:54AM +0200, Alexandre Belloni wrote:
> Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
> hang") added a workaround for the slow clock as it is not properly handled
> by its users.
> 
> Get and use the slow clock as it is necessary for the at91 reset
> controller.

You call clk_prepare_enable during probe without a matching
clk_disable_unprepare on module removal.

-- Sebastian

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Re: [PATCH 18/23] power/reset: at91-reset: get and use slow clock

[Alexandre Belloni]

On 05/08/2015 at 20:22:20 +0200, Sebastian Reichel wrote :
> Hi,
> 
> On Fri, Jul 31, 2015 at 11:39:54AM +0200, Alexandre Belloni wrote:
> > Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
> > hang") added a workaround for the slow clock as it is not properly handled
> > by its users.
> > 
> > Get and use the slow clock as it is necessary for the at91 reset
> > controller.
> 
> You call clk_prepare_enable during probe without a matching
> clk_disable_unprepare on module removal.
> 

They will never be compiled as modules as the Kconfig option is a bool
so we don't have a .remove and the module will never be removed.

Do you want me to change at91-reset and at91-poweroff to work as
modules?


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Re: [PATCH 18/23] power/reset: at91-reset: get and use slow clock

[Sebastian Reichel]

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Hi,

On Mon, Aug 10, 2015 at 05:50:05PM +0200, Alexandre Belloni wrote:
> On 05/08/2015 at 20:22:20 +0200, Sebastian Reichel wrote :
> > On Fri, Jul 31, 2015 at 11:39:54AM +0200, Alexandre Belloni wrote:
> > > Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
> > > hang") added a workaround for the slow clock as it is not properly handled
> > > by its users.
> > > 
> > > Get and use the slow clock as it is necessary for the at91 reset
> > > controller.
> > 
> > You call clk_prepare_enable during probe without a matching
> > clk_disable_unprepare on module removal.
> 
> They will never be compiled as modules as the Kconfig option is a
> bool so we don't have a .remove and the module will never be removed.

In that case the module_platform_driver() statement at the bottom
should be replaced with builtin_platform_driver().

> Do you want me to change at91-reset and at91-poweroff to work as
> modules?

That would also be fine.

-- Sebastian

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[PATCH 19/23] power/reset: at91-poweroff: get and use slow clock

[Alexandre Belloni]

Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.

Get and use the slow clock as it is necessary for the at91 shutdown
controller.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: linux-pm@vger.kernel.org
 drivers/power/reset/at91-poweroff.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
index 9847cfb7e23d..fadd1a41729b 100644
--- a/drivers/power/reset/at91-poweroff.c
+++ b/drivers/power/reset/at91-poweroff.c
@@ -10,6 +10,7 @@
  * warranty of any kind, whether express or implied.
  */
 
+#include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -48,6 +49,7 @@ static const char *shdwc_wakeup_modes[] = {
 };
 
 static void __iomem *at91_shdwc_base;
+static struct clk *sclk;
 
 static void __init at91_wakeup_status(void)
 {
@@ -122,6 +124,7 @@ static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
 static int at91_poweroff_probe(struct platform_device *pdev)
 {
 	struct resource *res;
+	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res);
@@ -130,6 +133,16 @@ static int at91_poweroff_probe(struct platform_device *pdev)
 		return PTR_ERR(at91_shdwc_base);
 	}
 
+	sclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sclk))
+		return PTR_ERR(sclk);
+
+	ret = clk_prepare_enable(sclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not enable slow clock\n");
+		return ret;
+	}
+
 	at91_wakeup_status();
 
 	if (pdev->dev.of_node)
-- 
2.1.4

Re: [PATCH 19/23] power/reset: at91-poweroff: get and use slow clock

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 457 bytes --]

Hi,

On Fri, Jul 31, 2015 at 11:39:55AM +0200, Alexandre Belloni wrote:
> Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
> hang") added a workaround for the slow clock as it is not properly handled
> by its users.
> 
> Get and use the slow clock as it is necessary for the at91 shutdown
> controller.

You call clk_prepare_enable during probe without a matching
clk_disable_unprepare on module removal.

-- Sebastian

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Re: [PATCH 00/23] ARM: at91: Properly handle slow clock

[Boris Brezillon]

Hi Alexandre,

On Fri, 31 Jul 2015 11:39:36 +0200
Alexandre Belloni <alexandre.belloni@free-electrons.com> wrote:

> Hi,
> 
> It was discovered that all the slow clock user were not properly claiming it.
> This can end up in a system hang because the last registered user is releasing
> it, and it gets disabled.
> 
> commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system hang")
> was a workaround. This series is adding the slow clock to the necessary drivers
> to avoid the issue and then removes that workaround.
> 
> The Documentation updates and DT patches should probably go through the AT91
> tree this cycle to avoid breakage.
> 
> Then the other patches can go through each subsystem tree. They are trivial
> enough to also go in this cycle.
> 
> The final clk patch depends on the other ones and may be taken for the next
> cycle to avoid synchronization issues.
> 
> I've thrown in a cleanup for at91-reset as it avoids adding support for that
> clock to the platform data initialization

I would have squashed commit 5 to 14 into a single patch, but apart
from that it looks good to me.

Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>

Thanks,

Boris

> 
> Changes in v2:
>  - statisticize the global in the atmel-st change
>  - merge at91_reset_of_probe() in at91_reset_probe()
>  - added patches from Boris for the TCB
>  - added the slow clock to the TCB
> 
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: linux-clk@vger.kernel.org
> Cc: linux-pm@vger.kernel.org
> Cc: linux-pwm@vger.kernel.org
> Cc: linux-watchdog@vger.kernel.org
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: rtc-linux@googlegroups.com
> Cc: Sebastian Reichel <sre@kernel.org>
> Cc: Stephen Boyd <sboyd@codeaurora.org>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Wim Van Sebroeck <wim@iguana.be>
> 
> Alexandre Belloni (20):
>   Documentation: dt: atmel-at91: add clocks to system timer, rstc and
>     shdwc
>   Documentation: watchdog: at91sam9_wdt: add clocks property
>   Documentation: dt: rtc: at91rm9200: add clocks property
>   ARM: at91/dt: at91rm9200: use slow clock where necessary
>   ARM: at91/dt: at91sam9260: use slow clock where necessary
>   ARM: at91/dt: at91sam9261: use slow clock where necessary
>   ARM: at91/dt: at91sam9263: use slow clock where necessary
>   ARM: at91/dt: at91sam9g45: use slow clock where necessary
>   ARM: at91/dt: at91sam9n12: use slow clock where necessary
>   ARM: at91/dt: at91sam9rl: use slow clock where necessary
>   ARM: at91/dt: at91sam9x5: use slow clock where necessary
>   ARM: at91/dt: sama5d3: use slow clock where necessary
>   ARM: at91/dt: sama5d4: use slow clock where necessary
>   rtc: at91rm9200: get and use slow clock
>   watchdog: at91sam9: get and use slow clock
>   power/reset: at91-reset: remove useless at91_reset_platform_probe()
>   power/reset: at91-reset: get and use slow clock
>   power/reset: at91-poweroff: get and use slow clock
>   clocksource: atmel-st: get and use slow clock
>   clk: at91: Revert "keep slow clk enabled to prevent system hang"
> 
> Boris Brezillon (3):
>   Documentation: dt: atmel-at91: add slow clock to tcb
>   clocksource: tcb_clksrc: fix setup_clkevents error path
>   misc: atmel_tclib: get and use slow clock
> 
>  .../devicetree/bindings/arm/atmel-at91.txt         | 13 +++--
>  .../bindings/rtc/atmel,at91rm9200-rtc.txt          |  2 +
>  .../devicetree/bindings/watchdog/atmel-wdt.txt     |  2 +
>  arch/arm/boot/dts/at91rm9200.dtsi                  | 10 ++--
>  arch/arm/boot/dts/at91sam9260.dtsi                 | 11 +++--
>  arch/arm/boot/dts/at91sam9261.dtsi                 |  7 ++-
>  arch/arm/boot/dts/at91sam9263.dtsi                 |  7 ++-
>  arch/arm/boot/dts/at91sam9g45.dtsi                 | 12 +++--
>  arch/arm/boot/dts/at91sam9n12.dtsi                 | 12 +++--
>  arch/arm/boot/dts/at91sam9rl.dtsi                  |  8 ++-
>  arch/arm/boot/dts/at91sam9x5.dtsi                  | 12 +++--
>  arch/arm/boot/dts/sama5d3.dtsi                     |  8 ++-
>  arch/arm/boot/dts/sama5d3_tcb1.dtsi                |  4 +-
>  arch/arm/boot/dts/sama5d4.dtsi                     | 12 +++--
>  drivers/clk/at91/clk-slow.c                        | 27 ----------
>  drivers/clocksource/tcb_clksrc.c                   | 10 +++-
>  drivers/clocksource/timer-atmel-st.c               | 31 ++++++++----
>  drivers/misc/atmel_tclib.c                         |  4 ++
>  drivers/power/reset/at91-poweroff.c                | 13 +++++
>  drivers/power/reset/at91-reset.c                   | 57 ++++++----------------
>  drivers/pwm/pwm-atmel-tcb.c                        | 23 ++++++---
>  drivers/rtc/rtc-at91rm9200.c                       | 27 ++++++++--
>  drivers/watchdog/at91sam9_wdt.c                    | 22 ++++++++-
>  include/linux/atmel_tc.h                           |  1 +
>  24 files changed, 206 insertions(+), 129 deletions(-)
> 



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH 00/23] ARM: at91: Properly handle slow clock

[Alexandre Belloni]

Hi,

On 31/07/2015 at 11:59:03 +0200, Boris Brezillon wrote :
> I would have squashed commit 5 to 14 into a single patch, but apart
> from that it looks good to me.
> 

I wanted to clearly list were the slow clock was needed for each soc. It
actually allowed me to find one that was missing.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Re: [PATCH 00/23] ARM: at91: Properly handle slow clock

[Alexandre Belloni]

Hi,

I realize now that I forgot to add the v2 tag in the subject lines. This
is really v2 :)

On 31/07/2015 at 11:39:36 +0200, Alexandre Belloni wrote :
> Hi,
> 
> It was discovered that all the slow clock user were not properly claiming it.
> This can end up in a system hang because the last registered user is releasing
> it, and it gets disabled.
> 
> commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system hang")
> was a workaround. This series is adding the slow clock to the necessary drivers
> to avoid the issue and then removes that workaround.
> 
> The Documentation updates and DT patches should probably go through the AT91
> tree this cycle to avoid breakage.
> 
> Then the other patches can go through each subsystem tree. They are trivial
> enough to also go in this cycle.
> 
> The final clk patch depends on the other ones and may be taken for the next
> cycle to avoid synchronization issues.
> 
> I've thrown in a cleanup for at91-reset as it avoids adding support for that
> clock to the platform data initialization
> 
> Changes in v2:
>  - statisticize the global in the atmel-st change
>  - merge at91_reset_of_probe() in at91_reset_probe()
>  - added patches from Boris for the TCB
>  - added the slow clock to the TCB
> 
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: linux-clk@vger.kernel.org
> Cc: linux-pm@vger.kernel.org
> Cc: linux-pwm@vger.kernel.org
> Cc: linux-watchdog@vger.kernel.org
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: rtc-linux@googlegroups.com
> Cc: Sebastian Reichel <sre@kernel.org>
> Cc: Stephen Boyd <sboyd@codeaurora.org>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Wim Van Sebroeck <wim@iguana.be>
> 
> Alexandre Belloni (20):
>   Documentation: dt: atmel-at91: add clocks to system timer, rstc and
>     shdwc
>   Documentation: watchdog: at91sam9_wdt: add clocks property
>   Documentation: dt: rtc: at91rm9200: add clocks property
>   ARM: at91/dt: at91rm9200: use slow clock where necessary
>   ARM: at91/dt: at91sam9260: use slow clock where necessary
>   ARM: at91/dt: at91sam9261: use slow clock where necessary
>   ARM: at91/dt: at91sam9263: use slow clock where necessary
>   ARM: at91/dt: at91sam9g45: use slow clock where necessary
>   ARM: at91/dt: at91sam9n12: use slow clock where necessary
>   ARM: at91/dt: at91sam9rl: use slow clock where necessary
>   ARM: at91/dt: at91sam9x5: use slow clock where necessary
>   ARM: at91/dt: sama5d3: use slow clock where necessary
>   ARM: at91/dt: sama5d4: use slow clock where necessary
>   rtc: at91rm9200: get and use slow clock
>   watchdog: at91sam9: get and use slow clock
>   power/reset: at91-reset: remove useless at91_reset_platform_probe()
>   power/reset: at91-reset: get and use slow clock
>   power/reset: at91-poweroff: get and use slow clock
>   clocksource: atmel-st: get and use slow clock
>   clk: at91: Revert "keep slow clk enabled to prevent system hang"
> 
> Boris Brezillon (3):
>   Documentation: dt: atmel-at91: add slow clock to tcb
>   clocksource: tcb_clksrc: fix setup_clkevents error path
>   misc: atmel_tclib: get and use slow clock
> 
>  .../devicetree/bindings/arm/atmel-at91.txt         | 13 +++--
>  .../bindings/rtc/atmel,at91rm9200-rtc.txt          |  2 +
>  .../devicetree/bindings/watchdog/atmel-wdt.txt     |  2 +
>  arch/arm/boot/dts/at91rm9200.dtsi                  | 10 ++--
>  arch/arm/boot/dts/at91sam9260.dtsi                 | 11 +++--
>  arch/arm/boot/dts/at91sam9261.dtsi                 |  7 ++-
>  arch/arm/boot/dts/at91sam9263.dtsi                 |  7 ++-
>  arch/arm/boot/dts/at91sam9g45.dtsi                 | 12 +++--
>  arch/arm/boot/dts/at91sam9n12.dtsi                 | 12 +++--
>  arch/arm/boot/dts/at91sam9rl.dtsi                  |  8 ++-
>  arch/arm/boot/dts/at91sam9x5.dtsi                  | 12 +++--
>  arch/arm/boot/dts/sama5d3.dtsi                     |  8 ++-
>  arch/arm/boot/dts/sama5d3_tcb1.dtsi                |  4 +-
>  arch/arm/boot/dts/sama5d4.dtsi                     | 12 +++--
>  drivers/clk/at91/clk-slow.c                        | 27 ----------
>  drivers/clocksource/tcb_clksrc.c                   | 10 +++-
>  drivers/clocksource/timer-atmel-st.c               | 31 ++++++++----
>  drivers/misc/atmel_tclib.c                         |  4 ++
>  drivers/power/reset/at91-poweroff.c                | 13 +++++
>  drivers/power/reset/at91-reset.c                   | 57 ++++++----------------
>  drivers/pwm/pwm-atmel-tcb.c                        | 23 ++++++---
>  drivers/rtc/rtc-at91rm9200.c                       | 27 ++++++++--
>  drivers/watchdog/at91sam9_wdt.c                    | 22 ++++++++-
>  include/linux/atmel_tc.h                           |  1 +
>  24 files changed, 206 insertions(+), 129 deletions(-)
> 
> -- 
> 2.1.4
> 

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com