power: reset: at91-poweroff: do not procede if at91_shdwc is allocated

There should be only one instance of struct shdwc in the system. This is
referenced through at91_shdwc. Return in probe if at91_shdwc is already
allocated.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index ad6e279..2b686c5 100644 (file)
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -255,6 +255,9 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
        if (!pdev->dev.of_node)
                return -ENODEV;
 
+       if (at91_shdwc)
+               return -EBUSY;
+
        at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL);
        if (!at91_shdwc)
                return -ENOMEM;