[PATCH v5 12/26] watchdog: renesas_wdt: Add R-Car Gen2 support

[Fabrizio Castro]

Due to commits:
* "ARM: shmobile: Add watchdog support",
* "ARM: shmobile: rcar-gen2: Add watchdog support", and
* "soc: renesas: rcar-rst: Enable watchdog as reset trigger for Gen2",
we now have everything we needed for the watchdog to work on Gen2 and
RZ/G1.

This commit adds "renesas,rcar-gen2-wdt" as compatible string for R-Car
Gen2 and RZ/G1, and since on those platforms the rwdt clock needs to be
always ON, when suspending to RAM we need to explicitly disable the
counting by clearing TME from RWTCSRA.

Signed-off-by: Fabrizio Castro <fabrizio.castro at bp.renesas.com>
Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram at bp.renesas.com>
---
v4->v5:
* various improvements suggested by Wolfram

 drivers/watchdog/renesas_wdt.c | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
index 831ef83..e972b7b 100644
--- a/drivers/watchdog/renesas_wdt.c
+++ b/drivers/watchdog/renesas_wdt.c
@@ -203,13 +203,29 @@ 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))
+		rwdt_write(priv, priv->cks, RWTCSRA);
+	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_write(priv, priv->cks | RWTCSRA_TME, RWTCSRA);
+	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-gen3-wdt", },
+	{ .compatible = "renesas,rcar-gen2-wdt", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, rwdt_ids);
@@ -218,6 +234,7 @@ 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,
-- 
2.7.4