rtc-at91rm9200: add configuration support

Add configuration support which can be used to implement SoC-specific
workarounds for broken hardware.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: Robert Nelson <Robert.Nelson@digikey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 38 insertions, 8 deletions

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index eeeb73f1fc3b..ab2024b159fa 100644
--- a/drivers/rtc/rtc-at91rm9200.c
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -42,6 +42,10 @@
 
 #define AT91_RTC_EPOCH          1900UL  /* just like arch/arm/common/rtctime.c */
 
+struct at91_rtc_config {
+};
+
+static const struct at91_rtc_config *at91_rtc_config;
 static DECLARE_COMPLETION(at91_rtc_updated);
 static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
 static void __iomem *at91_rtc_regs;
@@ -250,6 +254,36 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
         return IRQ_NONE;                /* not handled */
 }
 
+static const struct at91_rtc_config at91rm9200_config = {
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id at91_rtc_dt_ids[] = {
+        {
+                .compatible = "atmel,at91rm9200-rtc",
+                .data = &at91rm9200_config,
+        }, {
+                /* sentinel */
+        }
+};
+MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
+#endif
+
+static const struct at91_rtc_config *
+at91_rtc_get_config(struct platform_device *pdev)
+{
+        const struct of_device_id *match;
+
+        if (pdev->dev.of_node) {
+                match = of_match_node(at91_rtc_dt_ids, pdev->dev.of_node);
+                if (!match)
+                        return NULL;
+                return (const struct at91_rtc_config *)match->data;
+        }
+
+        return &at91rm9200_config;
+}
+
 static const struct rtc_class_ops at91_rtc_ops = {
         .read_time      = at91_rtc_readtime,
         .set_time       = at91_rtc_settime,
@@ -268,6 +302,10 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
         struct resource *regs;
         int ret = 0;
 
+        at91_rtc_config = at91_rtc_get_config(pdev);
+        if (!at91_rtc_config)
+                return -ENODEV;
+
         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         if (!regs) {
                 dev_err(&pdev->dev, "no mmio resource defined\n");
@@ -383,14 +421,6 @@ static int at91_rtc_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
 
-#ifdef CONFIG_OF
-static const struct of_device_id at91_rtc_dt_ids[] = {
-        { .compatible = "atmel,at91rm9200-rtc" },
-        { /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
-#endif
-
 static struct platform_driver at91_rtc_driver = {
         .remove         = __exit_p(at91_rtc_remove),
         .driver         = {