[PATCH 5.10 104/406] hwrng: iproc-rng200 - Implement suspend and resume calls

Greg Kroah-Hartman
2023-09-17T19:24:10Z

From: Florian Fainelli <florian.fainelli@broadcom.com>

[ Upstream commit 8e03dd62e5be811efbf0cbeba47e79e793519105 ]

Chips such as BCM7278 support system wide suspend/resume which will
cause the HWRNG block to lose its state and reset to its power on reset
register values. We need to cleanup and re-initialize the HWRNG for it
to be functional coming out of a system suspend cycle.

Fixes: c3577f6100ca ("hwrng: iproc-rng200 - Add support for BCM7278")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/char/hw_random/iproc-rng200.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
index 01583faf9893e..52c4aa66d8379 100644
--- a/drivers/char/hw_random/iproc-rng200.c
+++ b/drivers/char/hw_random/iproc-rng200.c
@@ -195,6 +195,8 @@ static int iproc_rng200_probe(struct platform_device *pdev)
return PTR_ERR(priv->base);
}

+ dev_set_drvdata(dev, priv);
+
priv->rng.name = "iproc-rng200";
priv->rng.read = iproc_rng200_read;
priv->rng.init = iproc_rng200_init;
@@ -212,6 +214,28 @@ static int iproc_rng200_probe(struct platform_device *pdev)
return 0;
}

+static int __maybe_unused iproc_rng200_suspend(struct device *dev)
+{
+ struct iproc_rng200_dev *priv = dev_get_drvdata(dev);
+
+ iproc_rng200_cleanup(&priv->rng);
+
+ return 0;
+}
+
+static int __maybe_unused iproc_rng200_resume(struct device *dev)
+{
+ struct iproc_rng200_dev *priv = dev_get_drvdata(dev);
+
+ iproc_rng200_init(&priv->rng);
+
+ return 0;
+}
+
+static const struct dev_pm_ops iproc_rng200_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(iproc_rng200_suspend, iproc_rng200_resume)
+};
+
static const struct of_device_id iproc_rng200_of_match[] = {
{ .compatible = "brcm,bcm2711-rng200", },
{ .compatible = "brcm,bcm7211-rng200", },
@@ -225,6 +249,7 @@ static struct platform_driver iproc_rng200_driver = {
.driver = {
.name = "iproc-rng200",
.of_match_table = iproc_rng200_of_match,
+ .pm = &iproc_rng200_pm_ops,
},
.probe = iproc_rng200_probe,
};
--
2.40.1