hwrng: iproc-rng200 - Implement suspend and resume calls

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>

diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c
index 34df3f0..440fe28 100644 (file)
--- a/drivers/char/hw_random/iproc-rng200.c
+++ b/drivers/char/hw_random/iproc-rng200.c
@@ -181,6 +181,8 @@ 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;
@@ -198,6 +200,28 @@ 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", },
@@ -211,6 +235,7 @@ 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,
 };