From: Melin Tomas <tomas.melin@vaisala.com>
To: "linux@roeck-us.net" <linux@roeck-us.net>,
"wim@linux-watchdog.org" <wim@linux-watchdog.org>
Cc: "linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>,
Melin Tomas <tomas.melin@vaisala.com>
Subject: [PATCH v3 2/4] watchdog: cadence_wdt: Calculate actual timeout limits
Date: Tue, 9 Jul 2019 20:09:05 +0000 [thread overview]
Message-ID: <20190709200801.42313-3-tomas.melin@vaisala.com> (raw)
In-Reply-To: <20190709200801.42313-1-tomas.melin@vaisala.com>
Maximum and minimum timeout values depend on the actual input clock
frequency and prescaler selection.
Signed-off-by: Tomas Melin <tomas.melin@vaisala.com>
---
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
next prev parent reply other threads:[~2019-07-09 20:09 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-09 20:09 [PATCH v3 0/4] watchdog: cadence_wdt: Support all available prescaler values Melin Tomas
2019-07-09 20:09 ` [PATCH v3 1/4] watchdog: cadence_wdt: Move clock detection earlier in probe Melin Tomas
2019-07-09 20:15 ` Guenter Roeck
2019-07-09 20:09 ` Melin Tomas [this message]
2019-07-09 20:14 ` [PATCH v3 2/4] watchdog: cadence_wdt: Calculate actual timeout limits Guenter Roeck
2019-07-09 20:09 ` [PATCH v3 4/4] watchdog: cadence_wdt: Support all available prescaler values Melin Tomas
2019-07-09 20:21 ` Guenter Roeck
2019-07-09 20:49 ` Melin Tomas
2019-07-09 21:07 ` Guenter Roeck
2019-07-10 19:20 ` Melin Tomas
2019-07-10 20:39 ` Guenter Roeck
2019-07-11 20:10 ` Melin Tomas
2019-07-09 20:09 ` [PATCH v3 3/4] watchdog: cadence_wdt: Group struct member init statements Melin Tomas
2019-07-09 20:16 ` Guenter Roeck
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