[PATCH 2.6] enable genrtc for MIPS

[PATCH 2.6] enable genrtc for MIPS

[Jun Sun]

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genrtc.c is like mips-rtc.c we have in 2.4, except it is shared by
other arches and has more capabilities (such as emulated alarms)

This patch implements the arch-specific code for genrtc based on 
MIPS's rtc_get_time() and rtc_set_time(), which are now implemented
by every MIPS board.  This essentially means with this patch
every MIPS machine now has a working genrtc for free.

Of course, individual board is still free to choose the old rtc.c
or implement some peculiar ones of its own - although I can't see why. :)

Jun

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diff -Nru linux/arch/mips/kernel/Makefile.orig linux/arch/mips/kernel/Makefile
--- linux/arch/mips/kernel/Makefile.orig	Mon Jan  5 10:33:35 2004
+++ linux/arch/mips/kernel/Makefile	Fri Jan 30 10:29:07 2004
@@ -51,6 +51,8 @@
 
 obj-$(CONFIG_MIPS64)		+= cpu-bugs64.o
 
+obj-$(CONFIG_GEN_RTC)		+= genrtc.o
+
 CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 EXTRA_AFLAGS := $(CFLAGS)
diff -Nru linux/arch/mips/kernel/genrtc.c.orig linux/arch/mips/kernel/genrtc.c
--- linux/arch/mips/kernel/genrtc.c.orig	Thu Jan 29 16:35:28 2004
+++ linux/arch/mips/kernel/genrtc.c	Thu Jan 29 17:22:56 2004
@@ -0,0 +1,65 @@
+/*
+ * A glue layer that provides RTC read/write to drivers/char/genrtc.c driver
+ * based on MIPS internal RTC routines.  It does take care locking
+ * issues so that we are SMP/Preemption safe.
+ *
+ * Copyright (C) 2004 MontaVista Software Inc.
+ * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
+ *
+ * Please read the COPYING file for all license details.
+ */
+
+#include <linux/config.h>
+#include <linux/spinlock.h>
+
+#include <asm/rtc.h>
+#include <asm/time.h>
+
+static spinlock_t mips_rtc_lock = SPIN_LOCK_UNLOCKED;
+
+unsigned int get_rtc_time(struct rtc_time *time)
+{
+	unsigned long nowtime;
+
+	spin_lock(&mips_rtc_lock);
+	nowtime = rtc_get_time();
+	to_tm(nowtime, time);
+	time->tm_year -= 1900;
+	spin_unlock(&mips_rtc_lock);
+
+	return RTC_24H;
+}
+
+int set_rtc_time(struct rtc_time *time)
+{
+	unsigned long nowtime;
+	int ret;
+
+	spin_lock(&mips_rtc_lock);
+	nowtime = mktime(time->tm_year+1900, time->tm_mon+1,
+			time->tm_mday, time->tm_hour, time->tm_min,
+			time->tm_sec);
+	ret = rtc_set_time(nowtime);
+	spin_unlock(&mips_rtc_lock);
+
+	return ret;
+}
+
+unsigned int get_rtc_ss(void)
+{
+	struct rtc_time h;
+
+	get_rtc_time(&h);
+	return h.tm_sec;
+}
+
+int get_rtc_pll(struct rtc_pll_info *pll)
+{
+	return -EINVAL;
+}
+
+int set_rtc_pll(struct rtc_pll_info *pll)
+{
+	return -EINVAL;
+}
+
diff -Nru linux/include/asm-mips/rtc.h.orig linux/include/asm-mips/rtc.h
--- linux/include/asm-mips/rtc.h.orig	Thu Oct 31 08:35:52 2002
+++ linux/include/asm-mips/rtc.h	Thu Jan 29 16:35:14 2004
@@ -1,10 +1,37 @@
-#ifndef _I386_RTC_H
-#define _I386_RTC_H
-
 /*
- * x86 uses the default access methods for the RTC.
+ * include/asm-mips/rtc.h 
+ *
+ * (Really an interface for drivers/char/genrtc.c)
+ *
+ * Copyright (C) 2004 MontaVista Software Inc.
+ * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
+ *
+ * Please read the COPYING file for all license details.
  */
 
-#include <asm-generic/rtc.h>
+#ifndef _MIPS_RTC_H
+#define _MIPS_RTC_H
+
+#ifdef __KERNEL__
+
+#include <linux/rtc.h>
+
+#define RTC_PIE 0x40            /* periodic interrupt enable */
+#define RTC_AIE 0x20            /* alarm interrupt enable */
+#define RTC_UIE 0x10            /* update-finished interrupt enable */
 
+/* some dummy definitions */
+#define RTC_BATT_BAD 0x100      /* battery bad */
+#define RTC_SQWE 0x08           /* enable square-wave output */
+#define RTC_DM_BINARY 0x04      /* all time/date values are BCD if clear */
+#define RTC_24H 0x02            /* 24 hour mode - else hours bit 7 means pm */
+#define RTC_DST_EN 0x01         /* auto switch DST - works f. USA only */
+
+unsigned int get_rtc_time(struct rtc_time *time);
+int set_rtc_time(struct rtc_time *time);
+unsigned int get_rtc_ss(void);
+int get_rtc_pll(struct rtc_pll_info *pll);
+int set_rtc_pll(struct rtc_pll_info *pll);
+
+#endif
 #endif

Re: [PATCH 2.6] enable genrtc for MIPS

[Maciej W. Rozycki]

On Fri, 30 Jan 2004, Jun Sun wrote:

> Of course, individual board is still free to choose the old rtc.c
> or implement some peculiar ones of its own - although I can't see why. :)

 s/old/full-featured/

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@ds2.pg.gda.pl, PGP key available        +

Re: [PATCH 2.6] enable genrtc for MIPS

[Atsushi Nemoto]

>>>>> On Fri, 30 Jan 2004 20:13:38 +0100 (CET), "Maciej W. Rozycki" <macro@ds2.pg.gda.pl> said:

>> Of course, individual board is still free to choose the old rtc.c
>> or implement some peculiar ones of its own - although I can't see
>> why. :)

macro>  s/old/full-featured/

No, I suppose s/rtc/mips-rtc/ is what the original patch means.

By the way, with this patch, individual board can not implement it's
own genrtc routines.  How about making gen_rtc_time, etc. pointer to
functions to allow overrides?

I think implementing rtc_get_time (mips specific) with get_rtc_time
(genrtc) is more efficient than implementing get_rtc_time with
rtc_get_time for most RTC chips.

---
Atsushi Nemoto

Re: [PATCH 2.6] enable genrtc for MIPS

[Geert Uytterhoeven]

On Sun, 1 Feb 2004, Atsushi Nemoto wrote:
> I think implementing rtc_get_time (mips specific) with get_rtc_time
> (genrtc) is more efficient than implementing get_rtc_time with
> rtc_get_time for most RTC chips.

Indeed, that's what I noticed a while ago, too.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

Re: [PATCH 2.6] enable genrtc for MIPS

[Jun Sun]

On Sun, Feb 01, 2004 at 08:30:05PM +0900, Atsushi Nemoto wrote:
> 
> By the way, with this patch, individual board can not implement it's
> own genrtc routines.  How about making gen_rtc_time, etc. pointer to
> functions to allow overrides?
> 

Is this necessary?  How about letting us wait until there is a sensible
need?

> I think implementing rtc_get_time (mips specific) with get_rtc_time
> (genrtc) is more efficient than implementing get_rtc_time with
> rtc_get_time for most RTC chips.
> 

If I understand you correctly, you like to have board rtc read routines to 
return a rtc structure instead of the unsigned long integer.

There are actually boards which makes the current implementation more efficient.  
See vr4181.

In general, however, this is not a bad idea, just involving a lot more
board level changes.  I think it deserves another patch or even debate.

Jun

Re: [PATCH 2.6] enable genrtc for MIPS

[Atsushi Nemoto]

>>>>> On Mon, 2 Feb 2004 13:19:50 -0800, Jun Sun <jsun@mvista.com> said:
>> By the way, with this patch, individual board can not implement
>> it's own genrtc routines.  How about making gen_rtc_time,
>> etc. pointer to functions to allow overrides?

jsun> Is this necessary?  How about letting us wait until there is a
jsun> sensible need?

OK, we can wait.  But still I suppose gen_rtc_time will become a
pointer sooner or later....

Anyway, I think using genrtc instead of mips-rtc is very good idea.
Thank you.

jsun> If I understand you correctly, you like to have board rtc read
jsun> routines to return a rtc structure instead of the unsigned long
jsun> integer.

jsun> There are actually boards which makes the current implementation
jsun> more efficient.  See vr4181.

I see.

jsun> In general, however, this is not a bad idea, just involving a
jsun> lot more board level changes.  I think it deserves another patch
jsun> or even debate.

Though I'm not have a real code yet, how about this idea?

1. Provide std_rtc_get_time (returns ulong) implemented with
   get_rtc_time (returns rtc struct) pointer.
2. Provide std_get_rtc_time (returns rtc struct) implemented with
   rtc_get_time returns ulong) pointer.
3. Each board implement its own rtc_get_time or get_rtc_time.
4. In generic time_init(), initialize rtc_get_time pointer or
   get_rtc_time pointer with std_rtc_get_time or std_get_rtc_time if
   they were NULL.

---
Atsushi Nemoto