2024-02-28 08:33:33

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 00/10] watchdog: rzg2l_wdt: Add support for RZ/G3S

From: Claudiu Beznea <[email protected]>

Hi,

Series adds watchdog support for Renesas RZ/G3S (R9A08G045) SoC.

Patches do the following:
- patch 1/10 makes the driver depend on ARCH_RZG2L || ARCH_R9A09G011
- patch 2/10 makes the driver depend on PM
- patches 3-7/10 adds fixes and cleanups for the watchdog driver
- patch 8/10 adds suspend to RAM to the watchdog driver (to be used by
RZ/G3S)
- patch 9/10 adapt for power domain support
- patch 10/10 documents the RZ/G3S support

Thank you,
Claudiu Beznea

Changes in v8:
- added patch 9
- collected tags

Changes in v7:
- updated the dependency on patch 2/9

Changes in v6:
- update patch 2/9 description
- fixed the dependency on COMPILE_TEST previously introduced in patch
2/9

Changes in v5:
- updated description of patch 2/9
- simplify the code in patch 2/9 by using on a new line:
depends on PM || COMPILE_TEST

Changes in v4:
- added patch "watchdog: rzg2l_wdt: Restrict the driver to ARCH_RZG2L and
ARCH_R9A09G011"
- collected tags

Changes in v3:
- make driver depend on PM not select it
- drop patches already accepted (patches 1, 10, 11 from v2)
- re-arranged the tags in patch 8/8 as they were messed by b4 am/shazam

Changes in v2:
- added patch "watchdog: rzg2l_wdt: Select PM"
- propagate the return status of rzg2l_wdt_start() to it's callers
in patch "watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()"
- propagate the return status of rzg2l_wdt_stop() to it's callers
in patch "watchdog: rzg2l_wdt: Check return status of pm_runtime_put()"
- removed pm_ptr() from patch "watchdog: rzg2l_wdt: Add suspend/resume support"
- s/G2UL/G2L in patch "dt-bindings: watchdog: renesas,wdt: Document RZ/G3S support"
- collected tags


Claudiu Beznea (10):
watchdog: rzg2l_wdt: Restrict the driver to ARCH_RZG2L and
ARCH_R9A09G011
watchdog: rzg2l_wdt: Make the driver depend on PM
watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()
watchdog: rzg2l_wdt: Check return status of pm_runtime_put()
watchdog: rzg2l_wdt: Remove reset de-assert from probe
watchdog: rzg2l_wdt: Remove comparison with zero
watchdog: rzg2l_wdt: Rely on the reset driver for doing proper reset
watchdog: rzg2l_wdt: Add suspend/resume support
watchdog: rzg2l_wdt: Power on the PM domain in rzg2l_wdt_restart()
dt-bindings: watchdog: renesas,wdt: Document RZ/G3S support

.../bindings/watchdog/renesas,wdt.yaml | 1 +
drivers/watchdog/Kconfig | 3 +-
drivers/watchdog/rzg2l_wdt.c | 123 +++++++++++-------
3 files changed, 76 insertions(+), 51 deletions(-)

--
2.39.2



2024-02-28 08:33:36

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 01/10] watchdog: rzg2l_wdt: Restrict the driver to ARCH_RZG2L and ARCH_R9A09G011

From: Claudiu Beznea <[email protected]>

The rzg2l_wdt driver is used only by ARCH_RZG2L and ARCH_R9A09G011
micro-architectures of Renesas. Thus, limit it's usage only to these.

Suggested-by: Biju Das <[email protected]>
Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- none

Changes in v4:
- none; this patch is introduced in v4

drivers/watchdog/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 4700b218340f..bdd1527bb916 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -921,7 +921,7 @@ config RENESAS_RZN1WDT

config RENESAS_RZG2LWDT
tristate "Renesas RZ/G2L WDT Watchdog"
- depends on ARCH_RENESAS || COMPILE_TEST
+ depends on ARCH_RZG2L || ARCH_R9A09G011 || COMPILE_TEST
select WATCHDOG_CORE
help
This driver adds watchdog support for the integrated watchdogs in the
--
2.39.2


2024-02-28 08:34:02

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 02/10] watchdog: rzg2l_wdt: Make the driver depend on PM

From: Claudiu Beznea <[email protected]>

The rzg2l_wdt watchdog driver cannot work w/o CONFIG_PM=y (e.g. the
clocks are enabled though pm_runtime_* specific APIs). To avoid building
a driver that doesn't work make explicit the dependency on CONFIG_PM.

Suggested-by: Guenter Roeck <[email protected]>
Signed-off-by: Claudiu Beznea <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
---

Changes in v8:
- collected tags

Changes in v7:
- updated the dependency to PM || COMPILE_TEST to be able to
compile-test the driver when compiling for a
!(ARCH_RZG2L || ARCH_R9A09G011) platform and CONFIG_PM is disabled

Changes in v6:
- update patch description
- fixed the dependency on COMPILE_TEST previously introduced

Changes in v5:
- updated patch description
- added on a new line the dependency on PM and COMPILE_TEST

Changes in v4:
- s/ARCH_RENESAS/ARCH_RZG2L || ARCH_R9A09G011 due to patch 1/9

Changes in v3:
- make driver depend on PM; with that the "unmet direct dependency"
Reported-by: kernel test robot <[email protected]>
was also fixed
- adapt commit message

Changes in v2:
- this patch is new

drivers/watchdog/Kconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index bdd1527bb916..cd2e29da7a54 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -922,6 +922,7 @@ config RENESAS_RZN1WDT
config RENESAS_RZG2LWDT
tristate "Renesas RZ/G2L WDT Watchdog"
depends on ARCH_RZG2L || ARCH_R9A09G011 || COMPILE_TEST
+ depends on PM || COMPILE_TEST
select WATCHDOG_CORE
help
This driver adds watchdog support for the integrated watchdogs in the
--
2.39.2


2024-02-28 08:34:06

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 03/10] watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()

From: Claudiu Beznea <[email protected]>

pm_runtime_get_sync() may return with error. In case it returns with error
dev->power.usage_count needs to be decremented. pm_runtime_resume_and_get()
takes care of this. Thus use it.

Along with it the rzg2l_wdt_set_timeout() function was updated to
propagate the result of rzg2l_wdt_start() to its caller.

Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L")
Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- none

Changes in v4:
- none

Changes in v3:
- none

Changes in v2:
- propagate the return code of rzg2l_wdt_start() to it's callers


drivers/watchdog/rzg2l_wdt.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 1741f98ca67c..d87d4f50180c 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -123,8 +123,11 @@ static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev)
static int rzg2l_wdt_start(struct watchdog_device *wdev)
{
struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+ int ret;

- pm_runtime_get_sync(wdev->parent);
+ ret = pm_runtime_resume_and_get(wdev->parent);
+ if (ret)
+ return ret;

/* Initialize time out */
rzg2l_wdt_init_timeout(wdev);
@@ -150,6 +153,8 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)

static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout)
{
+ int ret = 0;
+
wdev->timeout = timeout;

/*
@@ -159,10 +164,10 @@ static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int time
*/
if (watchdog_active(wdev)) {
rzg2l_wdt_stop(wdev);
- rzg2l_wdt_start(wdev);
+ ret = rzg2l_wdt_start(wdev);
}

- return 0;
+ return ret;
}

static int rzg2l_wdt_restart(struct watchdog_device *wdev,
--
2.39.2


2024-02-28 08:34:23

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 04/10] watchdog: rzg2l_wdt: Check return status of pm_runtime_put()

From: Claudiu Beznea <[email protected]>

pm_runtime_put() may return an error code. Check its return status.

Along with it the rzg2l_wdt_set_timeout() function was updated to
propagate the result of rzg2l_wdt_stop() to its caller.

Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L")
Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- none

Changes in v4:
- none

Changes in v3:
- none

Changes in v2:
- propagate the return code of rzg2l_wdt_stop() to it's callers


drivers/watchdog/rzg2l_wdt.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index d87d4f50180c..7bce093316c4 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -144,9 +144,13 @@ static int rzg2l_wdt_start(struct watchdog_device *wdev)
static int rzg2l_wdt_stop(struct watchdog_device *wdev)
{
struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+ int ret;

rzg2l_wdt_reset(priv);
- pm_runtime_put(wdev->parent);
+
+ ret = pm_runtime_put(wdev->parent);
+ if (ret < 0)
+ return ret;

return 0;
}
@@ -163,7 +167,10 @@ static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int time
* to reset the module) so that it is updated with new timeout values.
*/
if (watchdog_active(wdev)) {
- rzg2l_wdt_stop(wdev);
+ ret = rzg2l_wdt_stop(wdev);
+ if (ret)
+ return ret;
+
ret = rzg2l_wdt_start(wdev);
}

--
2.39.2


2024-02-28 08:35:33

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 07/10] watchdog: rzg2l_wdt: Rely on the reset driver for doing proper reset

From: Claudiu Beznea <[email protected]>

The reset driver has been adapted in commit da235d2fac21
("clk: renesas: rzg2l: Check reset monitor registers") to check the reset
monitor bits before declaring reset asserts/de-asserts as
successful/failure operations. With that, there is no need to keep the
reset workaround for RZ/V2M in place in the watchdog driver.

Signed-off-by: Claudiu Beznea <[email protected]>
Reviewed-by: Philipp Zabel <[email protected]>
---

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- none

Changes in v4:
- collected tag

Changes in v3:
- none

Changes in v2:
- none

drivers/watchdog/rzg2l_wdt.c | 39 ++++--------------------------------
1 file changed, 4 insertions(+), 35 deletions(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 29eb47bcf984..42f1d5d6f07e 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -8,7 +8,6 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
-#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -54,35 +53,11 @@ struct rzg2l_wdt_priv {
struct reset_control *rstc;
unsigned long osc_clk_rate;
unsigned long delay;
- unsigned long minimum_assertion_period;
struct clk *pclk;
struct clk *osc_clk;
enum rz_wdt_type devtype;
};

-static int rzg2l_wdt_reset(struct rzg2l_wdt_priv *priv)
-{
- int err, status;
-
- if (priv->devtype == WDT_RZV2M) {
- /* WDT needs TYPE-B reset control */
- err = reset_control_assert(priv->rstc);
- if (err)
- return err;
- ndelay(priv->minimum_assertion_period);
- err = reset_control_deassert(priv->rstc);
- if (err)
- return err;
- err = read_poll_timeout(reset_control_status, status,
- status != 1, 0, 1000, false,
- priv->rstc);
- } else {
- err = reset_control_reset(priv->rstc);
- }
-
- return err;
-}
-
static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv)
{
/* delay timer when change the setting register */
@@ -187,13 +162,12 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev,
unsigned long action, void *data)
{
struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+ int ret;

clk_prepare_enable(priv->pclk);
clk_prepare_enable(priv->osc_clk);

if (priv->devtype == WDT_RZG2L) {
- int ret;
-
ret = reset_control_deassert(priv->rstc);
if (ret)
return ret;
@@ -205,7 +179,9 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev,
rzg2l_wdt_write(priv, PEEN_FORCE, PEEN);
} else {
/* RZ/V2M doesn't have parity error registers */
- rzg2l_wdt_reset(priv);
+ ret = reset_control_reset(priv->rstc);
+ if (ret)
+ return ret;

wdev->timeout = 0;

@@ -297,13 +273,6 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)

priv->devtype = (uintptr_t)of_device_get_match_data(dev);

- if (priv->devtype == WDT_RZV2M) {
- priv->minimum_assertion_period = RZV2M_A_NSEC +
- 3 * F2CYCLE_NSEC(pclk_rate) + 5 *
- max(F2CYCLE_NSEC(priv->osc_clk_rate),
- F2CYCLE_NSEC(pclk_rate));
- }
-
pm_runtime_enable(&pdev->dev);

priv->wdev.info = &rzg2l_wdt_ident;
--
2.39.2


2024-02-28 08:35:54

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 10/10] dt-bindings: watchdog: renesas,wdt: Document RZ/G3S support

From: Claudiu Beznea <[email protected]>

Document the support for the watchdog IP available on RZ/G3S SoC. The
watchdog IP available on RZ/G3S SoC is identical to the one found on
RZ/G2L SoC.

Signed-off-by: Claudiu Beznea <[email protected]>
Acked-by: Conor Dooley <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
---

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- none

Changes in v4:
- none

Changes in v3:
- re-arranged the tags as my b4 am/shazam placed previously the
Ab, Rb tags before the author's Sob

Changes in v2:
- collected tags
- s/G2UL/G2L in patch description

Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml | 1 +
1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml b/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml
index 951a7d54135a..220763838df0 100644
--- a/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml
@@ -29,6 +29,7 @@ properties:
- renesas,r9a07g043-wdt # RZ/G2UL and RZ/Five
- renesas,r9a07g044-wdt # RZ/G2{L,LC}
- renesas,r9a07g054-wdt # RZ/V2L
+ - renesas,r9a08g045-wdt # RZ/G3S
- const: renesas,rzg2l-wdt

- items:
--
2.39.2


2024-02-28 08:44:19

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 05/10] watchdog: rzg2l_wdt: Remove reset de-assert from probe

From: Claudiu Beznea <[email protected]>

There is no need to de-assert the reset signal on probe as the watchdog
is not used prior executing start. Also, the clocks are not enabled in
probe (pm_runtime_enable() doesn't do that), thus this is another indicator
that the watchdog wasn't used previously like this. Instead, keep the
watchdog hardware in its previous state at probe (by default it is in
reset state), enable it when it is started and move it to reset state
when it is stopped. This saves some extra power when the watchdog is
unused.

Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- update patch title

Changes in v4:
- none

Changes in v3:
- none

Changes in v2:
- none

drivers/watchdog/rzg2l_wdt.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 7bce093316c4..93a49fd0c7aa 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -129,6 +129,10 @@ static int rzg2l_wdt_start(struct watchdog_device *wdev)
if (ret)
return ret;

+ ret = reset_control_deassert(priv->rstc);
+ if (ret)
+ return ret;
+
/* Initialize time out */
rzg2l_wdt_init_timeout(wdev);

@@ -146,7 +150,9 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
int ret;

- rzg2l_wdt_reset(priv);
+ ret = reset_control_assert(priv->rstc);
+ if (ret)
+ return ret;

ret = pm_runtime_put(wdev->parent);
if (ret < 0)
@@ -186,6 +192,12 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev,
clk_prepare_enable(priv->osc_clk);

if (priv->devtype == WDT_RZG2L) {
+ int ret;
+
+ ret = reset_control_deassert(priv->rstc);
+ if (ret)
+ return ret;
+
/* Generate Reset (WDTRSTB) Signal on parity error */
rzg2l_wdt_write(priv, 0, PECR);

@@ -236,13 +248,11 @@ static const struct watchdog_ops rzg2l_wdt_ops = {
.restart = rzg2l_wdt_restart,
};

-static void rzg2l_wdt_reset_assert_pm_disable(void *data)
+static void rzg2l_wdt_pm_disable(void *data)
{
struct watchdog_device *wdev = data;
- struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);

pm_runtime_disable(wdev->parent);
- reset_control_assert(priv->rstc);
}

static int rzg2l_wdt_probe(struct platform_device *pdev)
@@ -285,10 +295,6 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
return dev_err_probe(&pdev->dev, PTR_ERR(priv->rstc),
"failed to get cpg reset");

- ret = reset_control_deassert(priv->rstc);
- if (ret)
- return dev_err_probe(dev, ret, "failed to deassert");
-
priv->devtype = (uintptr_t)of_device_get_match_data(dev);

if (priv->devtype == WDT_RZV2M) {
@@ -309,9 +315,7 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
priv->wdev.timeout = WDT_DEFAULT_TIMEOUT;

watchdog_set_drvdata(&priv->wdev, priv);
- ret = devm_add_action_or_reset(&pdev->dev,
- rzg2l_wdt_reset_assert_pm_disable,
- &priv->wdev);
+ ret = devm_add_action_or_reset(&pdev->dev, rzg2l_wdt_pm_disable, &priv->wdev);
if (ret < 0)
return ret;

--
2.39.2


2024-02-28 08:44:50

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 06/10] watchdog: rzg2l_wdt: Remove comparison with zero

From: Claudiu Beznea <[email protected]>

devm_add_action_or_reset() could return -ENOMEM or zero. Thus, remove
comparison with zero of the returning value to make code simpler.

Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- none

Changes in v4:
- none

Changes in v3:
- none

Changes in v2:
- none


drivers/watchdog/rzg2l_wdt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 93a49fd0c7aa..29eb47bcf984 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -316,7 +316,7 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)

watchdog_set_drvdata(&priv->wdev, priv);
ret = devm_add_action_or_reset(&pdev->dev, rzg2l_wdt_pm_disable, &priv->wdev);
- if (ret < 0)
+ if (ret)
return ret;

watchdog_set_nowayout(&priv->wdev, nowayout);
--
2.39.2


2024-02-28 08:45:36

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 08/10] watchdog: rzg2l_wdt: Add suspend/resume support

From: Claudiu Beznea <[email protected]>

The RZ/G3S supports deep sleep states where power to most of the IP blocks
is cut off. To ensure proper working of the watchdog when resuming from
such states, the suspend function is stopping the watchdog and the resume
function is starting it. There is no need to configure the watchdog
in case the watchdog was stopped prior to starting suspend.

Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes in v8:
- none

Changes in v7:
- none

Changes in v6:
- none

Changes in v5:
- none

Changes in v4:
- none

Changes in v3:
- none

Changes in v2:
- remove the usage of pm_ptr()


drivers/watchdog/rzg2l_wdt.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 42f1d5d6f07e..c8c20cfb97a3 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -284,6 +284,7 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
priv->wdev.timeout = WDT_DEFAULT_TIMEOUT;

watchdog_set_drvdata(&priv->wdev, priv);
+ dev_set_drvdata(dev, priv);
ret = devm_add_action_or_reset(&pdev->dev, rzg2l_wdt_pm_disable, &priv->wdev);
if (ret)
return ret;
@@ -305,10 +306,35 @@ static const struct of_device_id rzg2l_wdt_ids[] = {
};
MODULE_DEVICE_TABLE(of, rzg2l_wdt_ids);

+static int rzg2l_wdt_suspend_late(struct device *dev)
+{
+ struct rzg2l_wdt_priv *priv = dev_get_drvdata(dev);
+
+ if (!watchdog_active(&priv->wdev))
+ return 0;
+
+ return rzg2l_wdt_stop(&priv->wdev);
+}
+
+static int rzg2l_wdt_resume_early(struct device *dev)
+{
+ struct rzg2l_wdt_priv *priv = dev_get_drvdata(dev);
+
+ if (!watchdog_active(&priv->wdev))
+ return 0;
+
+ return rzg2l_wdt_start(&priv->wdev);
+}
+
+static const struct dev_pm_ops rzg2l_wdt_pm_ops = {
+ LATE_SYSTEM_SLEEP_PM_OPS(rzg2l_wdt_suspend_late, rzg2l_wdt_resume_early)
+};
+
static struct platform_driver rzg2l_wdt_driver = {
.driver = {
.name = "rzg2l_wdt",
.of_match_table = rzg2l_wdt_ids,
+ .pm = &rzg2l_wdt_pm_ops,
},
.probe = rzg2l_wdt_probe,
};
--
2.39.2


2024-02-28 08:45:58

by Claudiu

[permalink] [raw]
Subject: [PATCH v8 09/10] watchdog: rzg2l_wdt: Power on the PM domain in rzg2l_wdt_restart()

From: Claudiu Beznea <[email protected]>

The rzg2l_wdt_restart() is called from atomic context. Calling
pm_runtime_{get_sync, resume_and_get}() or any other runtime PM resume
APIs is not an option as it may lead to issues as described in commit
e4cf89596c1f ("watchdog: rzg2l_wdt: Fix 'BUG: Invalid wait context'")
that removed the pm_runtime_get_sync() and used directly the
clk_prepare_enable() APIs.

Starting with RZ/G3S the watchdog could be part of its own software
controlled power domain (see the initial implementation in Link section).
In case the watchdog is not used the power domain is off and accessing
watchdog registers leads to aborts.

To solve this the patch powers on the power domain using
dev_pm_genpd_resume() API before enabling its clock. This is not
sleeping or taking any other locks as the power domain will not be
registered with GENPD_FLAG_IRQ_SAFE flags.

Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Claudiu Beznea <[email protected]>
---

Changes in v8:
- none, this patch is new

drivers/watchdog/rzg2l_wdt.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index c8c20cfb97a3..98e5e9914a5d 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/units.h>
@@ -164,6 +165,17 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev,
struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
int ret;

+ /*
+ * The device may be part of a power domain that is currently
+ * powered off. We need to power it up before accessing registers.
+ * We don't undo the dev_pm_genpd_resume() as the device need to
+ * be up for the reboot to happen. Also, as we are in atomic context
+ * here there is no need to increment PM runtime usage counter
+ * (to make sure pm_runtime_active() doesn't return wrong code).
+ */
+ if (!pm_runtime_active(wdev->parent))
+ dev_pm_genpd_resume(wdev->parent);
+
clk_prepare_enable(priv->pclk);
clk_prepare_enable(priv->osc_clk);

--
2.39.2


2024-03-18 12:44:12

by Claudiu

[permalink] [raw]
Subject: Re: [PATCH v8 00/10] watchdog: rzg2l_wdt: Add support for RZ/G3S

Hi,

Gentle ping!

Thank you,
Claudiu Beznea

On 28.02.2024 10:32, Claudiu wrote:
> From: Claudiu Beznea <[email protected]>
>
> Hi,
>
> Series adds watchdog support for Renesas RZ/G3S (R9A08G045) SoC.
>
> Patches do the following:
> - patch 1/10 makes the driver depend on ARCH_RZG2L || ARCH_R9A09G011
> - patch 2/10 makes the driver depend on PM
> - patches 3-7/10 adds fixes and cleanups for the watchdog driver
> - patch 8/10 adds suspend to RAM to the watchdog driver (to be used by
> RZ/G3S)
> - patch 9/10 adapt for power domain support
> - patch 10/10 documents the RZ/G3S support
>
> Thank you,
> Claudiu Beznea
>
> Changes in v8:
> - added patch 9
> - collected tags
>
> Changes in v7:
> - updated the dependency on patch 2/9
>
> Changes in v6:
> - update patch 2/9 description
> - fixed the dependency on COMPILE_TEST previously introduced in patch
> 2/9
>
> Changes in v5:
> - updated description of patch 2/9
> - simplify the code in patch 2/9 by using on a new line:
> depends on PM || COMPILE_TEST
>
> Changes in v4:
> - added patch "watchdog: rzg2l_wdt: Restrict the driver to ARCH_RZG2L and
> ARCH_R9A09G011"
> - collected tags
>
> Changes in v3:
> - make driver depend on PM not select it
> - drop patches already accepted (patches 1, 10, 11 from v2)
> - re-arranged the tags in patch 8/8 as they were messed by b4 am/shazam
>
> Changes in v2:
> - added patch "watchdog: rzg2l_wdt: Select PM"
> - propagate the return status of rzg2l_wdt_start() to it's callers
> in patch "watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()"
> - propagate the return status of rzg2l_wdt_stop() to it's callers
> in patch "watchdog: rzg2l_wdt: Check return status of pm_runtime_put()"
> - removed pm_ptr() from patch "watchdog: rzg2l_wdt: Add suspend/resume support"
> - s/G2UL/G2L in patch "dt-bindings: watchdog: renesas,wdt: Document RZ/G3S support"
> - collected tags
>
>
> Claudiu Beznea (10):
> watchdog: rzg2l_wdt: Restrict the driver to ARCH_RZG2L and
> ARCH_R9A09G011
> watchdog: rzg2l_wdt: Make the driver depend on PM
> watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()
> watchdog: rzg2l_wdt: Check return status of pm_runtime_put()
> watchdog: rzg2l_wdt: Remove reset de-assert from probe
> watchdog: rzg2l_wdt: Remove comparison with zero
> watchdog: rzg2l_wdt: Rely on the reset driver for doing proper reset
> watchdog: rzg2l_wdt: Add suspend/resume support
> watchdog: rzg2l_wdt: Power on the PM domain in rzg2l_wdt_restart()
> dt-bindings: watchdog: renesas,wdt: Document RZ/G3S support
>
> .../bindings/watchdog/renesas,wdt.yaml | 1 +
> drivers/watchdog/Kconfig | 3 +-
> drivers/watchdog/rzg2l_wdt.c | 123 +++++++++++-------
> 3 files changed, 76 insertions(+), 51 deletions(-)
>