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path: root/drivers/watchdog/renesas_wdt.c
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Diffstat (limited to 'drivers/watchdog/renesas_wdt.c')
-rw-r--r--drivers/watchdog/renesas_wdt.c87
1 files changed, 82 insertions, 5 deletions
diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
index 831ef83f6de1..6b8c6ddfe30b 100644
--- a/drivers/watchdog/renesas_wdt.c
+++ b/drivers/watchdog/renesas_wdt.c
@@ -16,6 +16,8 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/smp.h>
+#include <linux/sys_soc.h>
#include <linux/watchdog.h>
#define RWTCNT 0
@@ -49,6 +51,7 @@ struct rwdt_priv {
void __iomem *base;
struct watchdog_device wdev;
unsigned long clk_rate;
+ u16 time_left;
u8 cks;
};
@@ -107,6 +110,16 @@ static unsigned int rwdt_get_timeleft(struct watchdog_device *wdev)
return DIV_BY_CLKS_PER_SEC(priv, 65536 - val);
}
+static int rwdt_restart(struct watchdog_device *wdev, unsigned long action,
+ void *data)
+{
+ struct rwdt_priv *priv = watchdog_get_drvdata(wdev);
+
+ rwdt_start(wdev);
+ rwdt_write(priv, 0xffff, RWTCNT);
+ return 0;
+}
+
static const struct watchdog_info rwdt_ident = {
.options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
.identity = "Renesas WDT Watchdog",
@@ -118,8 +131,47 @@ static const struct watchdog_ops rwdt_ops = {
.stop = rwdt_stop,
.ping = rwdt_init_timeout,
.get_timeleft = rwdt_get_timeleft,
+ .restart = rwdt_restart,
};
+#if defined(CONFIG_ARCH_RCAR_GEN2) && defined(CONFIG_SMP)
+/*
+ * Watchdog-reset integration is broken on early revisions of R-Car Gen2 SoCs
+ */
+static const struct soc_device_attribute rwdt_quirks_match[] = {
+ {
+ .soc_id = "r8a7790",
+ .revision = "ES1.*",
+ .data = (void *)1, /* needs single CPU */
+ }, {
+ .soc_id = "r8a7791",
+ .revision = "ES[12].*",
+ .data = (void *)1, /* needs single CPU */
+ }, {
+ .soc_id = "r8a7792",
+ .revision = "*",
+ .data = (void *)0, /* needs SMP disabled */
+ },
+ { /* sentinel */ }
+};
+
+static bool rwdt_blacklisted(struct device *dev)
+{
+ const struct soc_device_attribute *attr;
+
+ attr = soc_device_match(rwdt_quirks_match);
+ if (attr && setup_max_cpus > (uintptr_t)attr->data) {
+ dev_info(dev, "Watchdog blacklisted on %s %s\n", attr->soc_id,
+ attr->revision);
+ return true;
+ }
+
+ return false;
+}
+#else /* !CONFIG_ARCH_RCAR_GEN2 || !CONFIG_SMP */
+static inline bool rwdt_blacklisted(struct device *dev) { return false; }
+#endif /* !CONFIG_ARCH_RCAR_GEN2 || !CONFIG_SMP */
+
static int rwdt_probe(struct platform_device *pdev)
{
struct rwdt_priv *priv;
@@ -128,6 +180,9 @@ static int rwdt_probe(struct platform_device *pdev)
unsigned long clks_per_sec;
int ret, i;
+ if (rwdt_blacklisted(&pdev->dev))
+ return -ENODEV;
+
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
@@ -176,6 +231,7 @@ static int rwdt_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, priv);
watchdog_set_drvdata(&priv->wdev, priv);
watchdog_set_nowayout(&priv->wdev, nowayout);
+ watchdog_set_restart_priority(&priv->wdev, 0);
/* This overrides the default timeout only if DT configuration was found */
ret = watchdog_init_timeout(&priv->wdev, 0, &pdev->dev);
@@ -203,12 +259,32 @@ static int rwdt_remove(struct platform_device *pdev)
return 0;
}
-/*
- * This driver does also fit for R-Car Gen2 (r8a779[0-4]) WDT. However, for SMP
- * to work there, one also needs a RESET (RST) driver which does not exist yet
- * due to HW issues. This needs to be solved before adding compatibles here.
- */
+static int __maybe_unused rwdt_suspend(struct device *dev)
+{
+ struct rwdt_priv *priv = dev_get_drvdata(dev);
+
+ if (watchdog_active(&priv->wdev)) {
+ priv->time_left = readw(priv->base + RWTCNT);
+ rwdt_stop(&priv->wdev);
+ }
+ return 0;
+}
+
+static int __maybe_unused rwdt_resume(struct device *dev)
+{
+ struct rwdt_priv *priv = dev_get_drvdata(dev);
+
+ if (watchdog_active(&priv->wdev)) {
+ rwdt_start(&priv->wdev);
+ rwdt_write(priv, priv->time_left, RWTCNT);
+ }
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rwdt_pm_ops, rwdt_suspend, rwdt_resume);
+
static const struct of_device_id rwdt_ids[] = {
+ { .compatible = "renesas,rcar-gen2-wdt", },
{ .compatible = "renesas,rcar-gen3-wdt", },
{ /* sentinel */ }
};
@@ -218,6 +294,7 @@ static struct platform_driver rwdt_driver = {
.driver = {
.name = "renesas_wdt",
.of_match_table = rwdt_ids,
+ .pm = &rwdt_pm_ops,
},
.probe = rwdt_probe,
.remove = rwdt_remove,