ARM: footbridge: trim down old ISA rtc setup

This fixes a "start_kernel(): bug: interrupts were enabled early".

rtc_cmos now takes care of initializing the ISA RTC and reading the
current time and date from it; there's no need to repeat that here,
thereby causing interrupts to be enabled too early.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 57 insertions, 0 deletions

diff --git a/arch/arm/mach-footbridge/isa-rtc.c b/arch/arm/mach-footbridge/isa-rtc.c
new file mode 100644
index 000000000000..07fde4051f78
--- /dev/null
+++ b/arch/arm/mach-footbridge/isa-rtc.c
@@ -0,0 +1,57 @@
+/*
+ *  arch/arm/mach-footbridge/isa-rtc.c
+ *
+ *  Copyright (C) 1998 Russell King.
+ *  Copyright (C) 1998 Phil Blundell
+ *
+ * CATS has a real-time clock, though the evaluation board doesn't.
+ *
+ * Changelog:
+ *  21-Mar-1998 RMK     Created
+ *  27-Aug-1998 PJB     CATS support
+ *  28-Dec-1998 APH     Made leds optional
+ *  20-Jan-1999 RMK     Started merge of EBSA285, CATS and NetWinder
+ *  16-Mar-1999 RMK     More support for EBSA285-like machines with RTCs in
+ */
+
+#define RTC_PORT(x)             (0x70+(x))
+#define RTC_ALWAYS_BCD          0
+
+#include <linux/init.h>
+#include <linux/mc146818rtc.h>
+#include <linux/bcd.h>
+#include <linux/io.h>
+
+#include "common.h"
+
+void __init isa_rtc_init(void)
+{
+        int reg_d, reg_b;
+
+        /*
+         * Probe for the RTC.
+         */
+        reg_d = CMOS_READ(RTC_REG_D);
+
+        /*
+         * make sure the divider is set
+         */
+        CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_REG_A);
+
+        /*
+         * Set control reg B
+         *   (24 hour mode, update enabled)
+         */
+        reg_b = CMOS_READ(RTC_REG_B) & 0x7f;
+        reg_b |= 2;
+        CMOS_WRITE(reg_b, RTC_REG_B);
+
+        if ((CMOS_READ(RTC_REG_A) & 0x7f) == RTC_REF_CLCK_32KHZ &&
+            CMOS_READ(RTC_REG_B) == reg_b) {
+                /*
+                 * We have a RTC.  Check the battery
+                 */
+                if ((reg_d & 0x80) == 0)
+                        printk(KERN_WARNING "RTC: *** warning: CMOS battery bad\n");
+        }
+}