Re: [PATCH RESEND v4 2/2] watchdog: rti_wdt: Add reaction control

Hi Andrew,

On 2/3/26 1:13 PM, Andrew Davis wrote:

On 2/3/26 12:19 PM, Judith Mendez wrote:

quoted

This allows to configure reaction between NMI and reset for WWD.

On K3 SoC's other than AM62L SoC [0], watchdog reset output is routed
to the ESM module which can subsequently route the signal to safety
master or SoC reset. On AM62L, the watchdog reset output is routed
to the SoC HW reset block. So, add a new compatible for AM62l to add
SoC data and configure reaction to reset instead of NMI.

[0] https://www.ti.com/product/AM62L
Signed-off-by: Judith Mendez <redacted>
---
  drivers/watchdog/rti_wdt.c | 32 ++++++++++++++++++++++++++++----
  1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
index be7d7db475911..483e22efedf9b 100644
--- a/drivers/watchdog/rti_wdt.c
+++ b/drivers/watchdog/rti_wdt.c

@@ -35,7 +35,8 @@

  #define RTIWWDRXCTRL    0xa4
  #define RTIWWDSIZECTRL    0xa8
-#define RTIWWDRX_NMI    0xa
+#define RTIWWDRXN_RST    0x5
+#define RTIWWDRXN_NMI    0xa
  #define RTIWWDSIZE_50P        0x50
  #define RTIWWDSIZE_25P        0x500

@@ -63,22 +64,29 @@

  static int heartbeat;
+struct rti_wdt_data {
+    bool nmi;
+};
+
  /*
   * struct to hold data for each WDT device
   * @base - base io address of WD device
   * @freq - source clock frequency of WDT
   * @wdd  - hold watchdog device as is in WDT core
+ * @data - hold configuration data
   */
  struct rti_wdt_device {
      void __iomem        *base;
      unsigned long        freq;
      struct watchdog_device    wdd;
+    const struct rti_wdt_data *data;

Don't store the whole device match data struct, just store the
information you need, so

* @nmi - Set to true if this WDT instance supports generating NMI
bool nmi;

quoted

  };
  static int rti_wdt_start(struct watchdog_device *wdd)
  {
      u32 timer_margin;
      struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd);
+    u8 reaction;
      int ret;
      ret = pm_runtime_resume_and_get(wdd->parent);

@@ -101,8 +109,13 @@ static int rti_wdt_start(struct watchdog_device 

*wdd)
       */
      wdd->min_hw_heartbeat_ms = 520 * wdd->timeout + MAX_HW_ERROR;
-    /* Generate NMI when wdt expires */
-    writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);
+    /* Reset device if wdt serviced outside of window or generate NMI 
if available */

I think where we had issues before was this comment, it should match the 
code
and it can do so while being very similar to the comment as it was before:

/* When WDT expires, generate an NMI or reset the device if NMI is not 
supported */

oops, sorry, will fix... again

quoted

+    if (wdt->data->nmi)
+        reaction = RTIWWDRXN_NMI;
+    else
+        reaction = RTIWWDRXN_RST;
+
+    writel_relaxed(reaction, wdt->base + RTIWWDRXCTRL);
      /* Open window size 50%; this is the largest window size 
available */
      writel_relaxed(RTIWWDSIZE_50P, wdt->base + RTIWWDSIZECTRL);

@@ -254,6 +267,8 @@ static int rti_wdt_probe(struct platform_device 

*pdev)
      wdd->timeout = DEFAULT_HEARTBEAT;
      wdd->parent = dev;
+    wdt->data = device_get_match_data(dev);

Should be rare, but this can fail to find match data so you should
check for NULL here. Then as above, just extract out the data you
need (nmi).

Thanks for reviewing!
I will fix accordingly and respin the series.

~ Judith