Re: [PATCH RESEND V4 3/3] watchdog: imx_sc: Add pretimeout support

From: Guenter Roeck
Date: Sun May 12 2019 - 09:29:48 EST

On 5/12/19 3:10 AM, Anson Huang wrote:
i.MX system controller watchdog can support pretimeout IRQ
via general SCU MU IRQ, it depends on IMX_SCU and driver MUST
be probed after SCU IPC ready, then enable corresponding SCU
IRQ group and register SCU IRQ notifier, when watchdog pretimeout
IRQ fires, SCU MU IRQ will be handled and watchdog pretimeout
notifier will be called to handle the event.

Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>

Revviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Other patches waiting for DT review. IMX API feedback below.

Side note: This patch depends on 'firmware: imx: enable
imx scu general irq function' which is not yet in mainline.

---
No change, just resend patch with correct encoding.
---
drivers/watchdog/Kconfig | 1 +
drivers/watchdog/imx_sc_wdt.c | 116 +++++++++++++++++++++++++++++++++++-------
2 files changed, 98 insertions(+), 19 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 7ea6037..e08238c 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -716,6 +716,7 @@ config IMX2_WDT
config IMX_SC_WDT
tristate "IMX SC Watchdog"
depends on HAVE_ARM_SMCCC
+ depends on IMX_SCU
select WATCHDOG_CORE
help
This is the driver for the system controller watchdog
diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c
index 49848b6..6ecc03f 100644
--- a/drivers/watchdog/imx_sc_wdt.c
+++ b/drivers/watchdog/imx_sc_wdt.c
@@ -4,6 +4,7 @@
*/
#include <linux/arm-smccc.h>
+#include <linux/firmware/imx/sci.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -33,11 +34,19 @@
#define SC_TIMER_WDOG_ACTION_PARTITION 0
+#define SC_IRQ_WDOG 1
+#define SC_IRQ_GROUP_WDOG 1
+
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0000);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+struct imx_sc_wdt_device {
+ struct watchdog_device wdd;
+ struct notifier_block wdt_notifier;
+};
+
static int imx_sc_wdt_ping(struct watchdog_device *wdog)
{
struct arm_smccc_res res;
@@ -85,24 +94,66 @@ static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog,
return res.a0 ? -EACCES : 0;
}
+static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog,
+ unsigned int pretimeout)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG,
+ pretimeout * 1000, 0, 0, 0, 0, 0, &res);
+ if (res.a0)
+ return -EACCES;
+
+ wdog->pretimeout = pretimeout;
+
+ return 0;
+}
+
+static int imx_sc_wdt_notify(struct notifier_block *nb,
+ unsigned long event, void *group)
+{
+ struct imx_sc_wdt_device *imx_sc_wdd =
+ container_of(nb,
+ struct imx_sc_wdt_device,
+ wdt_notifier);
+
+ if (event & SC_IRQ_WDOG &&
+ *(u8 *)group == SC_IRQ_GROUP_WDOG)
+ watchdog_notify_pretimeout(&imx_sc_wdd->wdd);

This should really not be necessary. Event mask and target group
(if needed with a wildcard for the group) should be parameters of
imx_scu_irq_register_notifier(), and be handled in the imx code.

Also, passing 'group' as pointed seems excessive. Might as well
pass it directly.

Guenter

+
+ return 0;
+}
+
+static void imx_sc_wdt_action(void *data)
+{
+ struct notifier_block *wdt_notifier = data;
+
+ imx_scu_irq_unregister_notifier(wdt_notifier);
+ imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
+ SC_IRQ_WDOG,
+ false);
+}
+
static const struct watchdog_ops imx_sc_wdt_ops = {
.owner = THIS_MODULE,
.start = imx_sc_wdt_start,
.stop = imx_sc_wdt_stop,
.ping = imx_sc_wdt_ping,
.set_timeout = imx_sc_wdt_set_timeout,
+ .set_pretimeout = imx_sc_wdt_set_pretimeout,
};
-static const struct watchdog_info imx_sc_wdt_info = {
+static struct watchdog_info imx_sc_wdt_info = {
.identity = "i.MX SC watchdog timer",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
- WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT,
+ WDIOF_MAGICCLOSE,
};
static int imx_sc_wdt_probe(struct platform_device *pdev)
{
+ struct imx_sc_wdt_device *imx_sc_wdd;
+ struct watchdog_device *wdog;
struct device *dev = &pdev->dev;
- struct watchdog_device *imx_sc_wdd;
int ret;
imx_sc_wdd = devm_kzalloc(dev, sizeof(*imx_sc_wdd), GFP_KERNEL);
@@ -111,42 +162,69 @@ static int imx_sc_wdt_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, imx_sc_wdd);
- imx_sc_wdd->info = &imx_sc_wdt_info;
- imx_sc_wdd->ops = &imx_sc_wdt_ops;
- imx_sc_wdd->min_timeout = 1;
- imx_sc_wdd->max_timeout = MAX_TIMEOUT;
- imx_sc_wdd->parent = dev;
- imx_sc_wdd->timeout = DEFAULT_TIMEOUT;
+ wdog = &imx_sc_wdd->wdd;
+ wdog->info = &imx_sc_wdt_info;
+ wdog->ops = &imx_sc_wdt_ops;
+ wdog->min_timeout = 1;
+ wdog->max_timeout = MAX_TIMEOUT;
+ wdog->parent = dev;
+ wdog->timeout = DEFAULT_TIMEOUT;
- watchdog_init_timeout(imx_sc_wdd, 0, dev);
- watchdog_stop_on_reboot(imx_sc_wdd);
- watchdog_stop_on_unregister(imx_sc_wdd);
+ watchdog_init_timeout(wdog, 0, dev);
+ watchdog_stop_on_reboot(wdog);
+ watchdog_stop_on_unregister(wdog);
- ret = devm_watchdog_register_device(dev, imx_sc_wdd);
+ ret = devm_watchdog_register_device(dev, wdog);
if (ret) {
dev_err(dev, "Failed to register watchdog device\n");
return ret;
}
+ ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
+ SC_IRQ_WDOG,
+ true);
+ if (ret) {
+ dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n");
+ return 0;
+ }
+
+ imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify;
+ ret = imx_scu_irq_register_notifier(&imx_sc_wdd->wdt_notifier);
+ if (ret) {
+ imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
+ SC_IRQ_WDOG,
+ false);
+ dev_warn(dev,
+ "Register irq notifier failed, pretimeout NOT supported\n");
+ return 0;
+ }
+
+ ret = devm_add_action_or_reset(dev, imx_sc_wdt_action,
+ &imx_sc_wdd->wdt_notifier);
+ if (!ret)
+ imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT;
+ else
+ dev_warn(dev, "Add action failed, pretimeout NOT supported\n");
+
return 0;
}
static int __maybe_unused imx_sc_wdt_suspend(struct device *dev)
{
- struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
+ struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
- if (watchdog_active(imx_sc_wdd))
- imx_sc_wdt_stop(imx_sc_wdd);
+ if (watchdog_active(&imx_sc_wdd->wdd))
+ imx_sc_wdt_stop(&imx_sc_wdd->wdd);
return 0;
}
static int __maybe_unused imx_sc_wdt_resume(struct device *dev)
{
- struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
+ struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
- if (watchdog_active(imx_sc_wdd))
- imx_sc_wdt_start(imx_sc_wdd);
+ if (watchdog_active(&imx_sc_wdd->wdd))
+ imx_sc_wdt_start(&imx_sc_wdd->wdd);
return 0;
}