rtc: pl031: avoid exposing alarm if no interrupt

If the RTC has no interrupt, there is little point in exposing the RTC
alarm capabilities, as it can't be used as a wakeup source nor can it
deliver an event to userspace.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/rtc/rtc-pl031.c b/drivers/rtc/rtc-pl031.c
index 777da06d53ee5cde58e9b1ee5388b8d6c38d7abd..64c77ec1b4ea23817fb04a4eab51226916186778 100644 (file)
--- a/drivers/rtc/rtc-pl031.c
+++ b/drivers/rtc/rtc-pl031.c
@@ -320,7 +320,7 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
        int ret;
        struct pl031_local *ldata;
        struct pl031_vendor_data *vendor = id->data;
-       struct rtc_class_ops *ops = &vendor->ops;
+       struct rtc_class_ops *ops;
        unsigned long time, data;
 
        ret = amba_request_regions(adev, NULL);
@@ -329,12 +329,14 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
 
        ldata = devm_kzalloc(&adev->dev, sizeof(struct pl031_local),
                             GFP_KERNEL);
-       if (!ldata) {
+       ops = devm_kmemdup(&adev->dev, &vendor->ops, sizeof(vendor->ops),
+                          GFP_KERNEL);
+       if (!ldata || !ops) {
                ret = -ENOMEM;
                goto out;
        }
-       ldata->vendor = vendor;
 
+       ldata->vendor = vendor;
        ldata->base = devm_ioremap(&adev->dev, adev->res.start,
                                   resource_size(&adev->res));
        if (!ldata->base) {
@@ -372,6 +374,13 @@ static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
                }
        }
 
+       if (!adev->irq[0]) {
+               /* When there's no interrupt, no point in exposing the alarm */
+               ops->read_alarm = NULL;
+               ops->set_alarm = NULL;
+               ops->alarm_irq_enable = NULL;
+       }
+
        device_init_wakeup(&adev->dev, true);
        ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,
                                        THIS_MODULE);