summaryrefslogtreecommitdiff
path: root/drivers/watchdog/rti_wdt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/watchdog/rti_wdt.c')
-rw-r--r--drivers/watchdog/rti_wdt.c47
1 files changed, 22 insertions, 25 deletions
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
index 9215793a1c81..d1f9ce4100a8 100644
--- a/drivers/watchdog/rti_wdt.c
+++ b/drivers/watchdog/rti_wdt.c
@@ -59,7 +59,9 @@
#define PON_REASON_EOF_NUM 0xCCCCBBBB
#define RESERVED_MEM_MIN_SIZE 12
-static int heartbeat = DEFAULT_HEARTBEAT;
+#define MAX_HW_ERROR 250
+
+static int heartbeat;
/*
* struct to hold data for each WDT device
@@ -97,7 +99,7 @@ static int rti_wdt_start(struct watchdog_device *wdd)
* to be 50% or less than that; we obviouly want to configure the open
* window as large as possible so we select the 50% option.
*/
- wdd->min_hw_heartbeat_ms = 500 * wdd->timeout;
+ wdd->min_hw_heartbeat_ms = 520 * wdd->timeout + MAX_HW_ERROR;
/* Generate NMI when wdt expires */
writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);
@@ -131,31 +133,33 @@ static int rti_wdt_setup_hw_hb(struct watchdog_device *wdd, u32 wsize)
* be petted during the open window; not too early or not too late.
* The HW configuration options only allow for the open window size
* to be 50% or less than that.
+ * To avoid any glitches, we accommodate 2% + max hardware error
+ * safety margin.
*/
switch (wsize) {
case RTIWWDSIZE_50P:
- /* 50% open window => 50% min heartbeat */
- wdd->min_hw_heartbeat_ms = 500 * heartbeat;
+ /* 50% open window => 52% min heartbeat */
+ wdd->min_hw_heartbeat_ms = 520 * heartbeat + MAX_HW_ERROR;
break;
case RTIWWDSIZE_25P:
- /* 25% open window => 75% min heartbeat */
- wdd->min_hw_heartbeat_ms = 750 * heartbeat;
+ /* 25% open window => 77% min heartbeat */
+ wdd->min_hw_heartbeat_ms = 770 * heartbeat + MAX_HW_ERROR;
break;
case RTIWWDSIZE_12P5:
- /* 12.5% open window => 87.5% min heartbeat */
- wdd->min_hw_heartbeat_ms = 875 * heartbeat;
+ /* 12.5% open window => 89.5% min heartbeat */
+ wdd->min_hw_heartbeat_ms = 895 * heartbeat + MAX_HW_ERROR;
break;
case RTIWWDSIZE_6P25:
- /* 6.5% open window => 93.5% min heartbeat */
- wdd->min_hw_heartbeat_ms = 935 * heartbeat;
+ /* 6.5% open window => 95.5% min heartbeat */
+ wdd->min_hw_heartbeat_ms = 955 * heartbeat + MAX_HW_ERROR;
break;
case RTIWWDSIZE_3P125:
- /* 3.125% open window => 96.9% min heartbeat */
- wdd->min_hw_heartbeat_ms = 969 * heartbeat;
+ /* 3.125% open window => 98.9% min heartbeat */
+ wdd->min_hw_heartbeat_ms = 989 * heartbeat + MAX_HW_ERROR;
break;
default:
@@ -233,14 +237,6 @@ static int rti_wdt_probe(struct platform_device *pdev)
return -EINVAL;
}
- /*
- * If watchdog is running at 32k clock, it is not accurate.
- * Adjust frequency down in this case so that we don't pet
- * the watchdog too often.
- */
- if (wdt->freq < 32768)
- wdt->freq = wdt->freq * 9 / 10;
-
pm_runtime_enable(dev);
ret = pm_runtime_resume_and_get(dev);
if (ret < 0) {
@@ -256,6 +252,7 @@ static int rti_wdt_probe(struct platform_device *pdev)
wdd->min_timeout = 1;
wdd->max_hw_heartbeat_ms = (WDT_PRELOAD_MAX << WDT_PRELOAD_SHIFT) /
wdt->freq * 1000;
+ wdd->timeout = DEFAULT_HEARTBEAT;
wdd->parent = dev;
watchdog_set_drvdata(wdd, wdt);
@@ -276,7 +273,8 @@ static int rti_wdt_probe(struct platform_device *pdev)
set_bit(WDOG_HW_RUNNING, &wdd->status);
time_left_ms = rti_wdt_get_timeleft_ms(wdd);
- heartbeat_ms = readl(wdt->base + RTIDWDPRLD);
+ /* AM62x TRM: texp = (RTIDWDPRLD + 1) * (2^13) / RTICLK1 */
+ heartbeat_ms = readl(wdt->base + RTIDWDPRLD) + 1;
heartbeat_ms <<= WDT_PRELOAD_SHIFT;
heartbeat_ms *= 1000;
do_div(heartbeat_ms, wdt->freq);
@@ -304,6 +302,7 @@ static int rti_wdt_probe(struct platform_device *pdev)
node = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
if (node) {
ret = of_address_to_resource(node, 0, &res);
+ of_node_put(node);
if (ret) {
dev_err(dev, "No memory address assigned to the region.\n");
goto err_iomap;
@@ -340,10 +339,8 @@ static int rti_wdt_probe(struct platform_device *pdev)
watchdog_init_timeout(wdd, heartbeat, dev);
ret = watchdog_register_device(wdd);
- if (ret) {
- dev_err(dev, "cannot register watchdog device\n");
+ if (ret)
goto err_iomap;
- }
if (last_ping)
watchdog_set_last_hw_keepalive(wdd, last_ping);
@@ -384,7 +381,7 @@ static struct platform_driver rti_wdt_driver = {
.of_match_table = rti_wdt_of_match,
},
.probe = rti_wdt_probe,
- .remove_new = rti_wdt_remove,
+ .remove = rti_wdt_remove,
};
module_platform_driver(rti_wdt_driver);