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-rw-r--r--arch/powerpc/platforms/powernv/opal-rtc.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-rtc.c b/arch/powerpc/platforms/powernv/opal-rtc.c
new file mode 100644
index 000000000..a9bcf9217
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-rtc.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PowerNV Real Time Clock.
+ *
+ * Copyright 2011 IBM Corp.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+
+#include <asm/opal.h>
+#include <asm/firmware.h>
+#include <asm/machdep.h>
+
+static void __init opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
+{
+ tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) +
+ bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
+ tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1;
+ tm->tm_mday = bcd2bin(y_m_d & 0xff);
+ tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff);
+ tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff);
+ tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff);
+ tm->tm_wday = -1;
+}
+
+time64_t __init opal_get_boot_time(void)
+{
+ struct rtc_time tm;
+ u32 y_m_d;
+ u64 h_m_s_ms;
+ __be32 __y_m_d;
+ __be64 __h_m_s_ms;
+ long rc = OPAL_BUSY;
+
+ if (!opal_check_token(OPAL_RTC_READ))
+ return 0;
+
+ while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+ rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
+ if (rc == OPAL_BUSY_EVENT) {
+ mdelay(OPAL_BUSY_DELAY_MS);
+ opal_poll_events(NULL);
+ } else if (rc == OPAL_BUSY) {
+ mdelay(OPAL_BUSY_DELAY_MS);
+ }
+ }
+ if (rc != OPAL_SUCCESS)
+ return 0;
+
+ y_m_d = be32_to_cpu(__y_m_d);
+ h_m_s_ms = be64_to_cpu(__h_m_s_ms);
+ opal_to_tm(y_m_d, h_m_s_ms, &tm);
+ return rtc_tm_to_time64(&tm);
+}
+
+static __init int opal_time_init(void)
+{
+ struct platform_device *pdev;
+ struct device_node *rtc;
+
+ rtc = of_find_node_by_path("/ibm,opal/rtc");
+ if (rtc) {
+ pdev = of_platform_device_create(rtc, "opal-rtc", NULL);
+ of_node_put(rtc);
+ } else {
+ if (opal_check_token(OPAL_RTC_READ) ||
+ opal_check_token(OPAL_READ_TPO))
+ pdev = platform_device_register_simple("opal-rtc", -1,
+ NULL, 0);
+ else
+ return -ENODEV;
+ }
+
+ return PTR_ERR_OR_ZERO(pdev);
+}
+machine_subsys_initcall(powernv, opal_time_init);