1 files changed, 44 insertions, 5 deletions

diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
index 024d54eda11e..0dede5beb3f1 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
@@ -121,6 +123,44 @@ static const struct watchdog_ops rwdt_ops = {
         .get_timeleft = rwdt_get_timeleft,
 };
 
+#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;
@@ -129,6 +169,9 @@ 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;
@@ -228,12 +271,8 @@ static int __maybe_unused rwdt_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(rwdt_pm_ops, rwdt_suspend, rwdt_resume);
 
-/*
- * 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 const struct of_device_id rwdt_ids[] = {
+        { .compatible = "renesas,rcar-gen2-wdt", },
         { .compatible = "renesas,rcar-gen3-wdt", },
         { /* sentinel */ }
 };