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-rw-r--r--arch/powerpc/platforms/maple/time.c170
1 files changed, 170 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/maple/time.c b/arch/powerpc/platforms/maple/time.c
new file mode 100644
index 000000000..91606411d
--- /dev/null
+++ b/arch/powerpc/platforms/maple/time.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org),
+ * IBM Corp.
+ */
+
+#undef DEBUG
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/adb.h>
+#include <linux/pmu.h>
+#include <linux/interrupt.h>
+#include <linux/mc146818rtc.h>
+#include <linux/bcd.h>
+#include <linux/of_address.h>
+
+#include <asm/sections.h>
+#include <asm/io.h>
+#include <asm/machdep.h>
+#include <asm/time.h>
+
+#include "maple.h"
+
+#ifdef DEBUG
+#define DBG(x...) printk(x)
+#else
+#define DBG(x...)
+#endif
+
+static int maple_rtc_addr;
+
+static int maple_clock_read(int addr)
+{
+ outb_p(addr, maple_rtc_addr);
+ return inb_p(maple_rtc_addr+1);
+}
+
+static void maple_clock_write(unsigned long val, int addr)
+{
+ outb_p(addr, maple_rtc_addr);
+ outb_p(val, maple_rtc_addr+1);
+}
+
+void maple_get_rtc_time(struct rtc_time *tm)
+{
+ do {
+ tm->tm_sec = maple_clock_read(RTC_SECONDS);
+ tm->tm_min = maple_clock_read(RTC_MINUTES);
+ tm->tm_hour = maple_clock_read(RTC_HOURS);
+ tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH);
+ tm->tm_mon = maple_clock_read(RTC_MONTH);
+ tm->tm_year = maple_clock_read(RTC_YEAR);
+ } while (tm->tm_sec != maple_clock_read(RTC_SECONDS));
+
+ if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY)
+ || RTC_ALWAYS_BCD) {
+ tm->tm_sec = bcd2bin(tm->tm_sec);
+ tm->tm_min = bcd2bin(tm->tm_min);
+ tm->tm_hour = bcd2bin(tm->tm_hour);
+ tm->tm_mday = bcd2bin(tm->tm_mday);
+ tm->tm_mon = bcd2bin(tm->tm_mon);
+ tm->tm_year = bcd2bin(tm->tm_year);
+ }
+ if ((tm->tm_year + 1900) < 1970)
+ tm->tm_year += 100;
+
+ tm->tm_wday = -1;
+}
+
+int maple_set_rtc_time(struct rtc_time *tm)
+{
+ unsigned char save_control, save_freq_select;
+ int sec, min, hour, mon, mday, year;
+
+ spin_lock(&rtc_lock);
+
+ save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */
+
+ maple_clock_write((save_control|RTC_SET), RTC_CONTROL);
+
+ save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
+
+ maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
+
+ sec = tm->tm_sec;
+ min = tm->tm_min;
+ hour = tm->tm_hour;
+ mon = tm->tm_mon;
+ mday = tm->tm_mday;
+ year = tm->tm_year;
+
+ if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+ sec = bin2bcd(sec);
+ min = bin2bcd(min);
+ hour = bin2bcd(hour);
+ mon = bin2bcd(mon);
+ mday = bin2bcd(mday);
+ year = bin2bcd(year);
+ }
+ maple_clock_write(sec, RTC_SECONDS);
+ maple_clock_write(min, RTC_MINUTES);
+ maple_clock_write(hour, RTC_HOURS);
+ maple_clock_write(mon, RTC_MONTH);
+ maple_clock_write(mday, RTC_DAY_OF_MONTH);
+ maple_clock_write(year, RTC_YEAR);
+
+ /* The following flags have to be released exactly in this order,
+ * otherwise the DS12887 (popular MC146818A clone with integrated
+ * battery and quartz) will not reset the oscillator and will not
+ * update precisely 500 ms later. You won't find this mentioned in
+ * the Dallas Semiconductor data sheets, but who believes data
+ * sheets anyway ... -- Markus Kuhn
+ */
+ maple_clock_write(save_control, RTC_CONTROL);
+ maple_clock_write(save_freq_select, RTC_FREQ_SELECT);
+
+ spin_unlock(&rtc_lock);
+
+ return 0;
+}
+
+static struct resource rtc_iores = {
+ .name = "rtc",
+ .flags = IORESOURCE_IO | IORESOURCE_BUSY,
+};
+
+time64_t __init maple_get_boot_time(void)
+{
+ struct rtc_time tm;
+ struct device_node *rtcs;
+
+ rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
+ if (rtcs) {
+ struct resource r;
+ if (of_address_to_resource(rtcs, 0, &r)) {
+ printk(KERN_EMERG "Maple: Unable to translate RTC"
+ " address\n");
+ goto bail;
+ }
+ if (!(r.flags & IORESOURCE_IO)) {
+ printk(KERN_EMERG "Maple: RTC address isn't PIO!\n");
+ goto bail;
+ }
+ maple_rtc_addr = r.start;
+ printk(KERN_INFO "Maple: Found RTC at IO 0x%x\n",
+ maple_rtc_addr);
+ }
+ bail:
+ of_node_put(rtcs);
+ if (maple_rtc_addr == 0) {
+ maple_rtc_addr = RTC_PORT(0); /* legacy address */
+ printk(KERN_INFO "Maple: No device node for RTC, assuming "
+ "legacy address (0x%x)\n", maple_rtc_addr);
+ }
+
+ rtc_iores.start = maple_rtc_addr;
+ rtc_iores.end = maple_rtc_addr + 7;
+ request_resource(&ioport_resource, &rtc_iores);
+
+ maple_get_rtc_time(&tm);
+ return rtc_tm_to_time64(&tm);
+}
+