On 02/17/2017 07:22 AM, Alexandre Belloni wrote:
On 17/02/2017 at 06:47:03 -0800, Guenter Roeck wrote:
On 02/16/2017 11:30 AM, Alexandre Belloni wrote:
When resuming for the deepest state on sama5d2, it is necessary to restore
MR as the registers are lost.
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
---
Changes in v2:
- cache mr beofre suspending
drivers/watchdog/sama5d4_wdt.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
index 2a60251806d2..5ddeb4803dc3 100644
--- a/drivers/watchdog/sama5d4_wdt.c
+++ b/drivers/watchdog/sama5d4_wdt.c
@@ -28,6 +28,7 @@
struct sama5d4_wdt {
struct watchdog_device wdd;
void __iomem *reg_base;
+ u32 mr;
Makes me wonder if we shouldn't just retain the original 'config'
(and maybe rename it to 'mr). After all, it _is_ used now.
};
static int wdt_timeout = WDT_DEFAULT_TIMEOUT;
@@ -248,11 +249,42 @@ static const struct of_device_id sama5d4_wdt_of_match[] = {
};
MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
+#ifdef CONFIG_PM_SLEEP
+static int sama5d4_wdt_suspend(struct device *dev)
+{
+ struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
+
+ wdt->mr = wdt_read(wdt, AT91_WDT_MR);
+
Wouldn't you want to stop the watchdog here if it is running,
ie set AT91_WDT_WDDIS ?
Some existing customers want the watchdog to continue to run while the
system is suspended.
+ return 0;
+}
+
+static int sama5d4_wdt_resume(struct device *dev)
+{
+ struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
+ u32 reg;
+
+ reg = wdt_read(wdt, AT91_WDT_MR);
+ if (reg & AT91_WDT_WDDIS)
+ wdt_write(wdt, AT91_WDT_MR, reg & ~AT91_WDT_WDDIS);
+
+ wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS);
Is that necessary ? Why not just write wdt->mr unconditionally ?
Because you can change WDV and WDD *OR* WDDIS but not both at the same
time.
Odd hardware ;-). Please add a comment explaining why the watchdog isn't
stopped on suspend, and why the AT91_WDT_MR has to be reprogrammed on resume.
Thanks,
Guenter
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