ARM: at91/rtc-at91sam9: each SoC can select the RTT device to use

For the RTT as RTC driver rtc-at91sam9, the platform_device structure
is filled during SoC initialization. This will allow to convert this
RTC driver as a standard platform driver.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
index a3ad957..65896a3 100644
--- a/drivers/rtc/rtc-at91sam9.c
+++ b/drivers/rtc/rtc-at91sam9.c
@@ -287,7 +287,7 @@
 /*
  * Initialize and install RTC driver
  */
-static int __init at91_rtc_probe(struct platform_device *pdev)
+static int __devinit at91_rtc_probe(struct platform_device *pdev)
 {
 	struct resource	*r;
 	struct sam9_rtc	*rtc;
@@ -360,7 +360,7 @@
 /*
  * Disable and remove the RTC driver
  */
-static int __exit at91_rtc_remove(struct platform_device *pdev)
+static int __devexit at91_rtc_remove(struct platform_device *pdev)
 {
 	struct sam9_rtc	*rtc = platform_get_drvdata(pdev);
 	u32		mr = rtt_readl(rtc, MR);
@@ -433,63 +433,20 @@
 #endif
 
 static struct platform_driver at91_rtc_driver = {
-	.driver.name	= "rtc-at91sam9",
-	.driver.owner	= THIS_MODULE,
-	.remove		= __exit_p(at91_rtc_remove),
+	.probe		= at91_rtc_probe,
+	.remove		= __devexit_p(at91_rtc_remove),
 	.shutdown	= at91_rtc_shutdown,
 	.suspend	= at91_rtc_suspend,
 	.resume		= at91_rtc_resume,
+	.driver		= {
+		.name	= "rtc-at91sam9",
+		.owner	= THIS_MODULE,
+	},
 };
 
-/* Chips can have more than one RTT module, and they can be used for more
- * than just RTCs.  So we can't just register as "the" RTT driver.
- *
- * A normal approach in such cases is to create a library to allocate and
- * free the modules.  Here we just use bus_find_device() as like such a
- * library, binding directly ... no runtime "library" footprint is needed.
- */
-static int __init at91_rtc_match(struct device *dev, void *v)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	int ret;
-
-	/* continue searching if this isn't the RTT we need */
-	if (strcmp("at91_rtt", pdev->name) != 0
-			|| pdev->id != CONFIG_RTC_DRV_AT91SAM9_RTT)
-		goto fail;
-
-	/* else we found it ... but fail unless we can bind to the RTC driver */
-	if (dev->driver) {
-		dev_dbg(dev, "busy, can't use as RTC!\n");
-		goto fail;
-	}
-	dev->driver = &at91_rtc_driver.driver;
-	if (device_attach(dev) == 0) {
-		dev_dbg(dev, "can't attach RTC!\n");
-		goto fail;
-	}
-	ret = at91_rtc_probe(pdev);
-	if (ret == 0)
-		return true;
-
-	dev_dbg(dev, "RTC probe err %d!\n", ret);
-fail:
-	return false;
-}
-
 static int __init at91_rtc_init(void)
 {
-	int status;
-	struct device *rtc;
-
-	status = platform_driver_register(&at91_rtc_driver);
-	if (status)
-		return status;
-	rtc = bus_find_device(&platform_bus_type, NULL,
-			NULL, at91_rtc_match);
-	if (!rtc)
-		platform_driver_unregister(&at91_rtc_driver);
-	return rtc ? 0 : -ENODEV;
+	return platform_driver_register(&at91_rtc_driver);
 }
 module_init(at91_rtc_init);