[linuxsh-dev] Dreamcast RTC routines

[M. R. B. <mr...@su...>]

Here's preliminary support for the Dreamcast AICA RTC registers - it adds
the appropiate calls to the machvec which allows the timer frequency and
RTC query stuff to work as intended.

I'll be writing mc146818rtc stuff in a bit.

M. R.

2000-08-31  M. R. Brown <mr...@0x...>

	* arch/sh/kernel/Makefile: Add dependency for rtc-aica.o for
	CONFIG_SH_DREAMCAST.
	* arch/sh/kernel/mach_dc.c: Add prototypes and pointers for the AICA
	RTC routines to the machvec.
	* arch/sh/kernel/time.c (time_init): Remove checks for
	MACH_DREAMCAST as we can just use the RTC routines defined in the
	machvec.
	* arch/sh/kernel/rtc-aica.c: New file.

Index: Makefile
===================================================================
RCS file: /cvsroot/linuxsh/kernel/arch/sh/kernel/Makefile,v
retrieving revision 1.30
diff -u -r1.30 Makefile
--- Makefile	2001/08/24 12:38:19	1.30
+++ Makefile	2001/09/01 06:08:03
@@ -74,7 +74,7 @@
 obj-$(CONFIG_HD64465)		+= setup_hd64465.o io_hd64465.o hd64465_gpio.o
 obj-$(CONFIG_SH_DMIDA)		+= mach_dmida.o
 obj-$(CONFIG_SH_EC3104)         += setup_ec3104.o io_ec3104.o mach_ec3104.o
-obj-$(CONFIG_SH_DREAMCAST)	+= mach_dc.o setup_dc.o io_dc.o
+obj-$(CONFIG_SH_DREAMCAST)	+= mach_dc.o setup_dc.o io_dc.o rtc-aica.o
 
 ifeq ($(CONFIG_SH_GENERIC),y)
 obj-y		+= $(machine-specific-objs)
Index: mach_dc.c
===================================================================
RCS file: /cvsroot/linuxsh/kernel/arch/sh/kernel/mach_dc.c,v
retrieving revision 1.4
diff -u -r1.4 mach_dc.c
--- mach_dc.c	2001/05/24 05:09:16	1.4
+++ mach_dc.c	2001/09/01 06:08:03
@@ -1,10 +1,11 @@
 /*
- *	$Id: mach_dc.c,v 1.4 2001/05/24 05:09:16 mrbrown Exp $
+ *	$Id: mach_dc.c,v 1.2 2001/09/01 04:45:08 mrbrown Exp $
  *	SEGA Dreamcast machine vector
  */
 
 #include <linux/config.h>
 #include <linux/init.h>
+#include <linux/time.h>
 
 #include <asm/machvec.h>
 #include <asm/machvec_init.h>
@@ -16,6 +17,10 @@
 void __init setup_dreamcast(void);
 void __init dreamcast_pcibios_init(void);
 
+/* Custom Dreamcast RTC routines */
+void aica_rtc_gettimeofday(struct timeval *tv);
+int aica_rtc_settimeofday(const struct timeval *tv);
+
 /*
  * The Machine Vector
  */
@@ -59,6 +64,9 @@
 	mv_init_arch:		setup_dreamcast,
 	mv_isa_port2addr:	dreamcast_isa_port2addr,
 	mv_irq_demux:		systemasic_irq_demux,
+
+	mv_rtc_gettimeofday:	aica_rtc_gettimeofday,
+	mv_rtc_settimeofday:	aica_rtc_settimeofday,
 
 	mv_hw_dreamcast:	1,
 };
Index: time.c
===================================================================
RCS file: /cvsroot/linuxsh/kernel/arch/sh/kernel/time.c,v
retrieving revision 1.29
diff -u -r1.29 time.c
--- time.c	2001/07/23 10:43:42	1.29
+++ time.c	2001/09/01 06:08:03
@@ -1,4 +1,4 @@
-/* $Id: time.c,v 1.29 2001/07/23 10:43:42 gniibe Exp $
+/* $Id: time.c,v 1.2 2001/09/01 04:45:48 mrbrown Exp $
  *
  *  linux/arch/sh/kernel/time.c
  *
@@ -359,17 +359,11 @@
 #endif
 #endif
 
-	if (MACH_DREAMCAST)
-		xtime.tv_sec = xtime.tv_usec = 0;
-	else
-		rtc_gettimeofday(&xtime);
+	rtc_gettimeofday(&xtime);
 
 	setup_irq(TIMER_IRQ, &irq0);
 
-	if (MACH_DREAMCAST)
-		timer_freq = 50*1000*1000/4;
-	else
-		timer_freq = get_timer_frequency();
+	timer_freq = get_timer_frequency();
 
 	module_clock = timer_freq * 4;

===================================================================
/* arch/sh/kernel/rtc-aica.c
 *
 * Dreamcast AICA RTC routines.
 *
 * Copyright (c) 2001 M. R. Brown <mr...@0x...>
 *
 * Released under the terms of the GNU GPL v2.0.
 *
 */

#include <linux/time.h>

#include <asm/io.h>

/* The AICA RTC has an Epoch of 1/1/1950, so we must subtract 20 years (in
   seconds to get the standard Unix Epoch when getting the time, and add 20
   years when setting the time. */
#define TWENTY_YEARS ((20 * 365LU + 5) * 86400)

/* The AICA RTC is represented by a 32-bit seconds counter stored in 2 16-bit
   registers.*/
#define AICA_RTC_SECS_H		0xa0710000
#define AICA_RTC_SECS_L		0xa0710004

/**
 * aica_rtc_gettimeofday - Get the time from the AICA RTC
 * @tv: pointer to resulting timeval
 *
 * Grabs the current RTC seconds counter and adjusts it to the Unix Epoch.
 */
void aica_rtc_gettimeofday(struct timeval *tv) {
	unsigned long val1, val2;

	do {
		val1 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) |
			(ctrl_inl(AICA_RTC_SECS_L) & 0xffff);

		val2 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) |
			(ctrl_inl(AICA_RTC_SECS_L) & 0xffff);
	} while (val1 != val2);

	tv->tv_sec = val1 - TWENTY_YEARS;

	/* Can't get microseconds with just a seconds counter. */
	tv->tv_usec = 0;
}

/**
 * aica_rtc_settimeofday - Set the AICA RTC to the current time
 * @tv: contains the timeval to set
 *
 * Adjusts the given @tv to the AICA Epoch and sets the RTC seconds counter.
 */
int aica_rtc_settimeofday(const struct timeval *tv) {
	unsigned long val1, val2;
	unsigned long secs = tv->tv_sec + TWENTY_YEARS;

	do {
		ctrl_outl((secs & 0xffff0000) >> 16, AICA_RTC_SECS_H);
		ctrl_outl((secs & 0xffff), AICA_RTC_SECS_L);

		val1 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) |
			(ctrl_inl(AICA_RTC_SECS_L) & 0xffff);

		val2 = ((ctrl_inl(AICA_RTC_SECS_H) & 0xffff) << 16) |
			(ctrl_inl(AICA_RTC_SECS_L) & 0xffff);
	} while (val1 != val2);

	return 0;
}