Maximum and minimum timeout values depend on the actual input clock
frequency and prescaler selection.
Signed-off-by: Tomas Melin <tomas.melin@xxxxxxxxxxx>
---
drivers/watchdog/cadence_wdt.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/watchdog/cadence_wdt.c b/drivers/watchdog/cadence_wdt.c
index ddbf602bdc40..a0d7666e7d20 100644
--- a/drivers/watchdog/cadence_wdt.c
+++ b/drivers/watchdog/cadence_wdt.c
@@ -18,9 +18,6 @@
#include <linux/watchdog.h>
#define CDNS_WDT_DEFAULT_TIMEOUT 10
-/* Supports 1 - 516 sec */
-#define CDNS_WDT_MIN_TIMEOUT 1
-#define CDNS_WDT_MAX_TIMEOUT 516
/* Restart key */
#define CDNS_WDT_RESTART_KEY 0x00001999
@@ -28,6 +25,10 @@
/* Counter register access key */
#define CDNS_WDT_REGISTER_ACCESS_KEY 0x00920000
+/* Counter control register, counter restart values */
+#define CDNS_WDT_CCR_CRV_MIN 0xFFF
+#define CDNS_WDT_CCR_CRV_MAX 0xFFFFFF
+
/* Counter value divisor */
#define CDNS_WDT_COUNTER_VALUE_DIVISOR 0x1000
@@ -317,7 +318,10 @@ static int cdns_wdt_probe(struct platform_device *pdev)
return ret;
clock_f = clk_get_rate(wdt->clk);
- if (clock_f <= CDNS_WDT_CLK_75MHZ) {
+ if (clock_f == 0) {
+ dev_err(dev, "invalid clock frequency, (f=%lu)\n", clock_f);
+ return -EINVAL;
+ } else if (clock_f <= CDNS_WDT_CLK_75MHZ) {
wdt->prescaler = CDNS_WDT_PRESCALE_512;
wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_512;
} else {
@@ -329,8 +333,10 @@ static int cdns_wdt_probe(struct platform_device *pdev)
cdns_wdt_device->info = &cdns_wdt_info;
cdns_wdt_device->ops = &cdns_wdt_ops;
cdns_wdt_device->timeout = CDNS_WDT_DEFAULT_TIMEOUT;
- cdns_wdt_device->min_timeout = CDNS_WDT_MIN_TIMEOUT;
- cdns_wdt_device->max_timeout = CDNS_WDT_MAX_TIMEOUT;
+ cdns_wdt_device->min_timeout =
+ CDNS_WDT_CCR_CRV_MIN * wdt->prescaler / clock_f;
+ cdns_wdt_device->max_timeout =
+ CDNS_WDT_CCR_CRV_MAX * wdt->prescaler / clock_f;
wdt->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(wdt->regs))
--
2.17.2
