powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks

Implements OPAL RTC and NVRAM support and wire all that up to
the powernv platform.

We use RTAS for RTC as a fallback if available. Using RTAS for nvram
is not supported yet, pending some rework/cleanup and generalization
of the pSeries & CHRP code. We also use RTAS fallbacks for power off
and reboot

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 97 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 000000000000..2aa7641aac9b
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-rtc.c
@@ -0,0 +1,97 @@
+/*
+ * PowerNV Real Time Clock.
+ *
+ * Copyright 2011 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+
+#include <asm/opal.h>
+#include <asm/firmware.h>
+
+static void 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);
+
+        GregorianDay(tm);
+}
+
+unsigned long __init opal_get_boot_time(void)
+{
+        struct rtc_time tm;
+        u32 y_m_d;
+        u64 h_m_s_ms;
+        long rc = OPAL_BUSY;
+
+        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+                rc = opal_rtc_read(&y_m_d, &h_m_s_ms);
+                if (rc == OPAL_BUSY_EVENT)
+                        opal_poll_events(NULL);
+                else
+                        mdelay(10);
+        }
+        if (rc != OPAL_SUCCESS)
+                return 0;
+        opal_to_tm(y_m_d, h_m_s_ms, &tm);
+        return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+                      tm.tm_hour, tm.tm_min, tm.tm_sec);
+}
+
+void opal_get_rtc_time(struct rtc_time *tm)
+{
+        long rc = OPAL_BUSY;
+        u32 y_m_d;
+        u64 h_m_s_ms;
+
+        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+                rc = opal_rtc_read(&y_m_d, &h_m_s_ms);
+                if (rc == OPAL_BUSY_EVENT)
+                        opal_poll_events(NULL);
+                else
+                        mdelay(10);
+        }
+        if (rc != OPAL_SUCCESS)
+                return;
+        opal_to_tm(y_m_d, h_m_s_ms, tm);
+}
+
+int opal_set_rtc_time(struct rtc_time *tm)
+{
+        long rc = OPAL_BUSY;
+        u32 y_m_d = 0;
+        u64 h_m_s_ms = 0;
+
+        y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
+        y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
+        y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
+        y_m_d |= ((u32)bin2bcd(tm->tm_mday));
+
+        h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
+        h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
+        h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
+
+        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+                rc = opal_rtc_write(y_m_d, h_m_s_ms);
+                if (rc == OPAL_BUSY_EVENT)
+                        opal_poll_events(NULL);
+                else
+                        mdelay(10);
+        }
+        return rc == OPAL_SUCCESS ? 0 : -EIO;
+}