1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index dc2a0ba969ce..911e75cdc125 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -37,6 +37,8 @@
 #include <linux/mod_devicetable.h>
 #include <linux/log2.h>
 #include <linux/pm.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
 
 /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
 #include <asm-generic/rtc.h>
@@ -1057,6 +1059,47 @@ static struct pnp_driver cmos_pnp_driver = {
 
 #endif  /* CONFIG_PNP */
 
+#ifdef CONFIG_OF
+static const struct of_device_id of_cmos_match[] = {
+        {
+                .compatible = "motorola,mc146818",
+        },
+        { },
+};
+MODULE_DEVICE_TABLE(of, of_cmos_match);
+
+static __init void cmos_of_init(struct platform_device *pdev)
+{
+        struct device_node *node = pdev->dev.of_node;
+        struct rtc_time time;
+        int ret;
+        const __be32 *val;
+
+        if (!node)
+                return;
+
+        val = of_get_property(node, "ctrl-reg", NULL);
+        if (val)
+                CMOS_WRITE(be32_to_cpup(val), RTC_CONTROL);
+
+        val = of_get_property(node, "freq-reg", NULL);
+        if (val)
+                CMOS_WRITE(be32_to_cpup(val), RTC_FREQ_SELECT);
+
+        get_rtc_time(&time);
+        ret = rtc_valid_tm(&time);
+        if (ret) {
+                struct rtc_time def_time = {
+                        .tm_year = 1,
+                        .tm_mday = 1,
+                };
+                set_rtc_time(&def_time);
+        }
+}
+#else
+static inline void cmos_of_init(struct platform_device *pdev) {}
+#define of_cmos_match NULL
+#endif
 /*----------------------------------------------------------------*/
 
 /* Platform setup should have set up an RTC device, when PNP is
@@ -1065,6 +1108,7 @@ static struct pnp_driver cmos_pnp_driver = {
 
 static int __init cmos_platform_probe(struct platform_device *pdev)
 {
+        cmos_of_init(pdev);
         cmos_wake_setup(&pdev->dev);
         return cmos_do_probe(&pdev->dev,
                         platform_get_resource(pdev, IORESOURCE_IO, 0),
@@ -1096,6 +1140,7 @@ static struct platform_driver cmos_platform_driver = {
 #ifdef CONFIG_PM
                 .pm             = &cmos_pm_ops,
 #endif
+                .of_match_table = of_cmos_match,
         }
 };