Generic RTC driver in 2.4.x?

Generic RTC driver in 2.4.x?

[Geert Uytterhoeven]

AFAIK the generic RTC driver is used on PA-RISC, PPC, and m68k.

Are you interested in a backport to 2.4.x?

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: [parisc-linux] Generic RTC driver in 2.4.x?

[Randolph Chung]

> AFAIK the generic RTC driver is used on PA-RISC, PPC, and m68k.
> 
> Are you interested in a backport to 2.4.x?

On parisc we already have a version of the generic RTC driver in our
2.4 tree. If there's something more "official" or common we can adopt
that version. 

randolph
-- 
Randolph Chung
Debian GNU/Linux Developer, hppa/ia64 ports
http://www.tausq.org/

Re: [parisc-linux] Generic RTC driver in 2.4.x?

[Tom Rini]

On Tue, Dec 24, 2002 at 03:51:47PM -0800, Randolph Chung wrote:
> > AFAIK the generic RTC driver is used on PA-RISC, PPC, and m68k.
> > 
> > Are you interested in a backport to 2.4.x?
> 
> On parisc we already have a version of the generic RTC driver in our
> 2.4 tree. If there's something more "official" or common we can adopt
> that version. 

Similarly, PPC has had it's own 'generic' RTC driver in the kernel for
ages, so there's no pressing need, but if the 2.5 version makes its way
back into 2.4 (as the 2.5 version has some minor changes needed for
everyone which weren't in the 2.4 m68k version), we can easily switch to
that version.

-- 
Tom Rini (TR1265)
http://gate.crashing.org/~trini/

Re: [parisc-linux] Generic RTC driver in 2.4.x?

[Geert Uytterhoeven]

On Thu, 26 Dec 2002, Tom Rini wrote:
> On Tue, Dec 24, 2002 at 03:51:47PM -0800, Randolph Chung wrote:
> > > AFAIK the generic RTC driver is used on PA-RISC, PPC, and m68k.
> > > 
> > > Are you interested in a backport to 2.4.x?
> > 
> > On parisc we already have a version of the generic RTC driver in our
> > 2.4 tree. If there's something more "official" or common we can adopt
> > that version. 
> 
> Similarly, PPC has had it's own 'generic' RTC driver in the kernel for
> ages, so there's no pressing need, but if the 2.5 version makes its way
> back into 2.4 (as the 2.5 version has some minor changes needed for
> everyone which weren't in the 2.4 m68k version), we can easily switch to
> that version.

I already merged some of your 2.5.x changes with the driver in the m68k 2.4.x
tree.

I'll do some more merges, and get back to you...

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: [parisc-linux] Generic RTC driver in 2.4.x?

[Geert Uytterhoeven]

On Sat, 28 Dec 2002, Geert Uytterhoeven wrote:
> On Thu, 26 Dec 2002, Tom Rini wrote:
> > On Tue, Dec 24, 2002 at 03:51:47PM -0800, Randolph Chung wrote:
> > > > AFAIK the generic RTC driver is used on PA-RISC, PPC, and m68k.
> > > >
> > > > Are you interested in a backport to 2.4.x?
> > >
> > > On parisc we already have a version of the generic RTC driver in our
> > > 2.4 tree. If there's something more "official" or common we can adopt
> > > that version.
> >
> > Similarly, PPC has had it's own 'generic' RTC driver in the kernel for
> > ages, so there's no pressing need, but if the 2.5 version makes its way
> > back into 2.4 (as the 2.5 version has some minor changes needed for
> > everyone which weren't in the 2.4 m68k version), we can easily switch to
> > that version.
> 
> I already merged some of your 2.5.x changes with the driver in the m68k 2.4.x
> tree.
> 
> I'll do some more merges, and get back to you...

The following patch adds the generic RTC driver to 2.4.20 (applies fine to
2.4.21-pre2). This driver provides a /dev/rtc-compatible interface to the real
time clock on machines without a PC-style RTC chip. It is used as the primary
RTC driver on m68k, pa-risc, and ppc. This driver is already present in 2.5.x.

Pa-risc and ppc people (any other users?), please send me your enhancements (or
just ack if none are necessary), so I can send genrtc to Marcelo.

Thanks!

 Documentation/Configure.help            |   28 +
 arch/m68k/config.in                     |    5 
 arch/m68k/kernel/m68k_ksyms.c           |    5 
 arch/m68k/kernel/setup.c                |    3 
 arch/m68k/q40/config.c                  |   41 ++
 drivers/char/Makefile                   |    1 
 include/asm-m68k/machdep.h              |    4 
 include/asm-m68k/rtc.h                  |   44 ++
 include/linux/rtc.h                     |   28 +
 linux-m68k-2.4.20/drivers/char/genrtc.c |  524 ++++++++++++++++++++++++++++++++ 10 files changed, 678 insertions, 5 deletions

--- linux-2.4.20/Documentation/Configure.help	Tue Oct 29 18:40:45 2002
+++ linux-m68k-2.4.20/Documentation/Configure.help	Wed Oct 16 11:01:53 2002
@@ -18959,6 +18959,34 @@
   The module is called rtc.o. If you want to compile it as a module,
   say M here and read <file:Documentation/modules.txt>.
 
+Generic Real Time Clock Support
+CONFIG_GEN_RTC
+  If you say Y here and create a character special file /dev/rtc with
+  major number 10 and minor number 135 using mknod ("man mknod"), you
+  will get access to the real time clock (or hardware clock) built
+  into your computer.
+
+  In 2.4 and later kernels this is the only way to set and get rtc
+  time on m68k systems so it is highly recommended.
+
+  It reports status information via the file /proc/driver/rtc and its 
+  behaviour is set by various ioctls on /dev/rtc. If you enable the
+  "extended RTC operation" below it will also provide an emulation
+  for RTC_UIE which is required by some programs and may improve
+  precision in some cases.
+
+  This driver is also available as a module ( = code which can be
+  inserted in and removed from the running kernel whenever you want).
+  The module is called genrtc.o. If you want to compile it as a module,
+  say M here and read <file:Documentation/modules.txt>. To load the
+  module automaticaly add 'alias char-major-10-135 genrtc' to your
+  /etc/modules.conf
+
+Extended RTC operation
+CONFIG_GEN_RTC_X
+  Provides an emulation for RTC_UIE which is required by some programs 
+  and may improve precision of the generic RTC support in some cases.
+
 Tadpole ANA H8 Support
 CONFIG_H8
   The Hitachi H8/337 is a microcontroller used to deal with the power
--- linux-2.4.20/arch/m68k/config.in	Fri Sep 13 10:14:59 2002
+++ linux-m68k-2.4.20/arch/m68k/config.in	Tue Aug 13 09:14:30 2002
@@ -517,8 +517,11 @@
    if [ "$CONFIG_SUN3" = "y" ]; then
       define_bool CONFIG_GEN_RTC y
    else
-      bool 'Generic /dev/rtc emulation' CONFIG_GEN_RTC
+      tristate 'Generic /dev/rtc emulation' CONFIG_GEN_RTC      
    fi
+fi
+if [ "$CONFIG_GEN_RTC" != "n" ]; then
+   bool '   Extended RTC operation' CONFIG_GEN_RTC_X
 fi
 bool 'Unix98 PTY support' CONFIG_UNIX98_PTYS
 if [ "$CONFIG_UNIX98_PTYS" = "y" ]; then
--- linux-2.4.20/arch/m68k/kernel/m68k_ksyms.c	Thu Jan  4 22:00:55 2001
+++ linux-m68k-2.4.20/arch/m68k/kernel/m68k_ksyms.c	Fri Mar  1 12:29:44 2002
@@ -18,6 +18,7 @@
 #include <asm/checksum.h>
 #include <asm/hardirq.h>
 #include <asm/softirq.h>
+#include <asm/rtc.h>
 
 asmlinkage long long __ashldi3 (long long, int);
 asmlinkage long long __ashrdi3 (long long, int);
@@ -49,6 +50,10 @@
 EXPORT_SYMBOL(kernel_set_cachemode);
 #endif /* !CONFIG_SUN3 */
 EXPORT_SYMBOL(m68k_debug_device);
+EXPORT_SYMBOL(mach_hwclk);
+EXPORT_SYMBOL(mach_get_ss);
+EXPORT_SYMBOL(mach_get_rtc_pll);
+EXPORT_SYMBOL(mach_set_rtc_pll);
 EXPORT_SYMBOL(dump_fpu);
 EXPORT_SYMBOL(dump_thread);
 EXPORT_SYMBOL(strnlen);
--- linux-2.4.20/arch/m68k/kernel/setup.c	Fri Sep 13 10:15:01 2002
+++ linux-m68k-2.4.20/arch/m68k/kernel/setup.c	Mon Sep  9 13:07:29 2002
@@ -90,6 +90,9 @@
 void (*mach_gettod) (int*, int*, int*, int*, int*, int*);
 int (*mach_hwclk) (int, struct rtc_time*) = NULL;
 int (*mach_set_clock_mmss) (unsigned long) = NULL;
+unsigned int (*mach_get_ss)(void) = NULL;
+int (*mach_get_rtc_pll)(struct rtc_pll_info *) = NULL;
+int (*mach_set_rtc_pll)(struct rtc_pll_info *) = NULL;
 void (*mach_reset)( void );
 void (*mach_halt)( void ) = NULL;
 void (*mach_power_off)( void ) = NULL;
--- linux-2.4.20/arch/m68k/q40/config.c	Fri Sep 13 10:15:02 2002
+++ linux-m68k-2.4.20/arch/m68k/q40/config.c	Mon Sep  9 13:07:29 2002
@@ -58,7 +58,10 @@
 extern void q40_gettod (int *year, int *mon, int *day, int *hour,
                            int *min, int *sec);
 extern int q40_hwclk (int, struct rtc_time *);
+extern unsigned int q40_get_ss (void);
 extern int q40_set_clock_mmss (unsigned long);
+static int q40_get_rtc_pll(struct rtc_pll_info *pll);
+static int q40_set_rtc_pll(struct rtc_pll_info *pll);
 extern void q40_reset (void);
 void q40_halt(void);
 extern void q40_waitbut(void);
@@ -196,6 +199,9 @@
     mach_gettimeoffset   = q40_gettimeoffset; 
     mach_gettod  	 = q40_gettod;
     mach_hwclk           = q40_hwclk; 
+    mach_get_ss          = q40_get_ss; 
+    mach_get_rtc_pll     = q40_get_rtc_pll; 
+    mach_set_rtc_pll     = q40_set_rtc_pll; 
     mach_set_clock_mmss	 = q40_set_clock_mmss;
 
     mach_reset		 = q40_reset;
@@ -331,6 +337,11 @@
 	return 0;
 }
 
+unsigned int q40_get_ss()
+{
+	return bcd2bin(Q40_RTC_SECS);
+}
+
 /*
  * Set the minutes and seconds from seconds value 'nowtime'.  Fail if
  * clock is out by > 30 minutes.  Logic lifted from atari code.
@@ -362,3 +373,33 @@
 	return retval;
 }
 
+
+/* get and set PLL calibration of RTC clock */
+#define Q40_RTC_PLL_MASK ((1<<5)-1)
+#define Q40_RTC_PLL_SIGN (1<<5)
+
+static int q40_get_rtc_pll(struct rtc_pll_info *pll)
+{
+      int tmp=Q40_RTC_CTRL;
+      pll->pll_value = tmp & Q40_RTC_PLL_MASK;
+      if (tmp & Q40_RTC_PLL_SIGN) 
+	  pll->pll_value = -pll->pll_value;
+      pll->pll_max=31;
+      pll->pll_min=-31;
+      pll->pll_posmult=512;
+      pll->pll_negmult=256;
+      pll->pll_clock=125829120;
+      return 0;
+  }
+
+static int q40_set_rtc_pll(struct rtc_pll_info *pll)
+{
+  if (!pll->pll_ctrl){
+      /* the docs are a bit unclear so I am doublesetting RTC_WRITE here ... */
+      int tmp=(pll->pll_value & 31) | (pll->pll_value<0 ? 32 : 0) | Q40_RTC_WRITE;
+      Q40_RTC_CTRL |= Q40_RTC_WRITE;
+      Q40_RTC_CTRL = tmp;
+      Q40_RTC_CTRL &= ~(Q40_RTC_WRITE);
+      return 0;
+  } else return -EINVAL;
+}
--- linux-2.4.20/drivers/char/Makefile	Wed Nov 27 11:02:06 2002
+++ linux-m68k-2.4.20/drivers/char/Makefile	Tue Nov 26 13:24:32 2002
@@ -222,6 +222,7 @@
 obj-$(CONFIG_PC110_PAD) += pc110pad.o
 obj-$(CONFIG_MK712_MOUSE) += mk712.o
 obj-$(CONFIG_RTC) += rtc.o
+obj-$(CONFIG_GEN_RTC) += genrtc.o
 obj-$(CONFIG_EFI_RTC) += efirtc.o
 ifeq ($(CONFIG_PPC),)
   obj-$(CONFIG_NVRAM) += nvram.o
--- /dev/null	Mon Mar 18 12:17:27 2002
+++ linux-m68k-2.4.20/drivers/char/genrtc.c	Sun Jan  5 15:24:28 2003
@@ -0,0 +1,524 @@
+/*
+ *	Real Time Clock interface for q40 and other m68k machines
+ *      emulate some RTC irq capabilities in software
+ *
+ *      Copyright (C) 1999 Richard Zidlicky
+ *
+ *	based on Paul Gortmaker's rtc.c device and
+ *           Sam Creasey Generic rtc driver
+ *
+ *	This driver allows use of the real time clock (built into
+ *	nearly all computers) from user space. It exports the /dev/rtc
+ *	interface supporting various ioctl() and also the /proc/dev/rtc
+ *	pseudo-file for status information.
+ *
+ *	The ioctls can be used to set the interrupt behaviour where
+ *  supported.
+ *
+ *	The /dev/rtc interface will block on reads until an interrupt
+ *	has been received. If a RTC interrupt has already happened,
+ *	it will output an unsigned long and then block. The output value
+ *	contains the interrupt status in the low byte and the number of
+ *	interrupts since the last read in the remaining high bytes. The
+ *	/dev/rtc interface can also be used with the select(2) call.
+ *
+ *	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.
+ *
+
+ *      1.01 fix for 2.3.X                    rz@linux-m68k.org
+ *      1.02 merged with code from genrtc.c   rz@linux-m68k.org
+ *      1.03 make it more portable            zippel@linux-m68k.org
+ *      1.04 removed useless timer code       rz@linux-m68k.org
+ *      1.05 portable RTC_UIE emulation       rz@linux-m68k.org
+ *      1.06 set_rtc_time can return an error trini@kernel.crashing.org
+ */
+
+#define RTC_VERSION	"1.06"
+
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/rtc.h>
+
+/*
+ *	We sponge a minor off of the misc major. No need slurping
+ *	up another valuable major dev number for this. If you add
+ *	an ioctl, make sure you don't conflict with SPARC's RTC
+ *	ioctls.
+ */
+
+static DECLARE_WAIT_QUEUE_HEAD(gen_rtc_wait);
+
+static int gen_rtc_ioctl(struct inode *inode, struct file *file,
+		     unsigned int cmd, unsigned long arg);
+
+/*
+ *	Bits in gen_rtc_status.
+ */
+
+#define RTC_IS_OPEN		0x01	/* means /dev/rtc is in use	*/
+
+unsigned char gen_rtc_status;		/* bitmapped status byte.	*/
+unsigned long gen_rtc_irq_data;		/* our output to the world	*/
+
+/* months start at 0 now */
+unsigned char days_in_mo[] =
+{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+static int irq_active;
+
+#ifdef CONFIG_GEN_RTC_X
+struct tq_struct genrtc_task;
+static struct timer_list timer_task;
+
+static unsigned int oldsecs;
+static int lostint;
+static int tt_exp;
+
+void gen_rtc_timer(unsigned long data);
+
+static volatile int stask_active;              /* schedule_task */
+static volatile int ttask_active;              /* timer_task */
+static int stop_rtc_timers;                    /* don't requeue tasks */
+static spinlock_t gen_rtc_lock = SPIN_LOCK_UNLOCKED;
+
+/*
+ * Routine to poll RTC seconds field for change as often as posible,
+ * after first RTC_UIE use timer to reduce polling
+ */
+void genrtc_troutine(void *data)
+{
+	unsigned int tmp = get_rtc_ss();
+	
+	if (stop_rtc_timers) {
+		stask_active = 0;
+		return;
+	}
+
+	if (oldsecs != tmp){
+		oldsecs = tmp;
+
+		timer_task.function = gen_rtc_timer;
+		timer_task.expires = jiffies + HZ - (HZ/10);
+		tt_exp=timer_task.expires;
+		ttask_active=1;
+		stask_active=0;
+		add_timer(&timer_task);
+
+		gen_rtc_interrupt(0);
+	} else if (schedule_task(&genrtc_task) == 0)
+		stask_active = 0;
+}
+
+void gen_rtc_timer(unsigned long data)
+{
+	lostint = get_rtc_ss() - oldsecs ;
+	if (lostint<0) 
+		lostint = 60 - lostint;
+	if (time_after(jiffies, tt_exp))
+		printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n",
+		       jiffies-tt_exp);
+	ttask_active=0;
+	stask_active=1;
+	if ((schedule_task(&genrtc_task) == 0))
+		stask_active = 0;
+}
+
+/* 
+ * call gen_rtc_interrupt function to signal an RTC_UIE,
+ * arg is unused.
+ * Could be invoked either from a real interrupt handler or
+ * from some routine that periodically (eg 100HZ) monitors
+ * whether RTC_SECS changed
+ */
+void gen_rtc_interrupt(unsigned long arg)
+{
+	/*  We store the status in the low byte and the number of
+	 *	interrupts received since the last read in the remainder
+	 *	of rtc_irq_data.  */
+
+	gen_rtc_irq_data += 0x100;
+	gen_rtc_irq_data &= ~0xff;
+	gen_rtc_irq_data |= RTC_UIE;
+
+	if (lostint){
+		printk("genrtc: system delaying clock ticks?\n");
+		/* increment count so that userspace knows something is wrong */
+		gen_rtc_irq_data += ((lostint-1)<<8);
+		lostint = 0;
+	}
+
+	wake_up_interruptible(&gen_rtc_wait);
+}
+
+/*
+ *	Now all the various file operations that we export.
+ */
+static ssize_t gen_rtc_read(struct file *file, char *buf,
+			size_t count, loff_t *ppos)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	unsigned long data;
+	ssize_t retval;
+
+	if (count != sizeof (unsigned int) && count != sizeof (unsigned long))
+		return -EINVAL;
+
+	if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data)
+		return -EAGAIN;
+
+	add_wait_queue(&gen_rtc_wait, &wait);
+	retval = -ERESTARTSYS;
+
+	while (1) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		data = xchg(&gen_rtc_irq_data, 0);
+		if (data)
+			break;
+		if (signal_pending(current))
+			goto out;
+		schedule();
+	}
+
+	/* first test allows optimizer to nuke this case for 32-bit machines */
+	if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) {
+		unsigned int uidata = data;
+		retval = put_user(uidata, (unsigned long *)buf);
+	}
+	else {
+		retval = put_user(data, (unsigned long *)buf);
+	}
+	if (!retval)
+		retval = sizeof(unsigned long);
+ out:
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&gen_rtc_wait, &wait);
+
+	return retval;
+}
+
+static unsigned int gen_rtc_poll(struct file *file,
+				 struct poll_table_struct *wait)
+{
+	poll_wait(file, &gen_rtc_wait, wait);
+	if (gen_rtc_irq_data != 0)
+		return POLLIN | POLLRDNORM;
+	return 0;
+}
+
+#endif
+
+/*
+ * Used to disable/enable interrupts, only RTC_UIE supported
+ * We also clear out any old irq data after an ioctl() that
+ * meddles with the interrupt enable/disable bits.
+ */
+
+static inline void gen_clear_rtc_irq_bit(unsigned char bit)
+{
+#ifdef CONFIG_GEN_RTC_X
+	stop_rtc_timers = 1;
+	if (ttask_active){
+		del_timer_sync(&timer_task);
+		ttask_active = 0;
+	}
+	while (stask_active)
+		schedule();
+
+	spin_lock(&gen_rtc_lock);
+	irq_active = 0;
+	spin_unlock(&gen_rtc_lock);
+#endif
+}
+
+static inline int gen_set_rtc_irq_bit(unsigned char bit)
+{
+#ifdef CONFIG_GEN_RTC_X
+	spin_lock(&gen_rtc_lock);
+	if ( !irq_active ) {
+		irq_active = 1;
+		stop_rtc_timers = 0;
+		lostint = 0;
+		genrtc_task.routine = genrtc_troutine;
+		oldsecs = get_rtc_ss();
+		init_timer(&timer_task);
+
+		stask_active = 1;
+		if (schedule_task(&genrtc_task) == 0){
+			stask_active = 0;
+		}
+	}
+	spin_unlock(&gen_rtc_lock);
+	gen_rtc_irq_data = 0;
+	return 0;
+#else
+	return -EINVAL;
+#endif
+}
+
+static int gen_rtc_ioctl(struct inode *inode, struct file *file,
+			 unsigned int cmd, unsigned long arg)
+{
+	struct rtc_time wtime;
+	struct rtc_pll_info pll;
+
+	switch (cmd) {
+
+	case RTC_PLL_GET:
+	    if (get_rtc_pll(&pll))
+	 	    return -EINVAL;
+	    else
+		    return copy_to_user((void *)arg, &pll, sizeof pll) ? -EFAULT : 0;
+
+	case RTC_PLL_SET:
+		if (!capable(CAP_SYS_TIME))
+			return -EACCES;
+		if (copy_from_user(&pll, (struct rtc_pll_info*)arg,
+				   sizeof(pll)))
+			return -EFAULT;
+	    return set_rtc_pll(&pll);
+
+	case RTC_UIE_OFF:	/* disable ints from RTC updates.	*/
+		gen_clear_rtc_irq_bit(RTC_UIE);
+		return 0;
+
+	case RTC_UIE_ON:	/* enable ints for RTC updates.	*/
+	        return gen_set_rtc_irq_bit(RTC_UIE);
+
+	case RTC_RD_TIME:	/* Read the time/date from RTC	*/
+		/* this doesn't get week-day, who cares */
+		memset(&wtime, 0, sizeof(wtime));
+		get_rtc_time(&wtime);
+
+		return copy_to_user((void *)arg, &wtime, sizeof(wtime)) ? -EFAULT : 0;
+
+	case RTC_SET_TIME:	/* Set the RTC */
+	    {
+		int year;
+		unsigned char leap_yr;
+
+		if (!capable(CAP_SYS_TIME))
+			return -EACCES;
+
+		if (copy_from_user(&wtime, (struct rtc_time *)arg,
+				   sizeof(wtime)))
+			return -EFAULT;
+
+		year = wtime.tm_year + 1900;
+		leap_yr = ((!(year % 4) && (year % 100)) ||
+			   !(year % 400));
+
+		if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1))
+			return -EINVAL;
+
+		if (wtime.tm_mday < 0 || wtime.tm_mday >
+		    (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr)))
+			return -EINVAL;
+
+		if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
+		    wtime.tm_min < 0 || wtime.tm_min >= 60 ||
+		    wtime.tm_sec < 0 || wtime.tm_sec >= 60)
+			return -EINVAL;
+
+		return set_rtc_time(&wtime);
+	    }
+	}
+
+	return -EINVAL;
+}
+
+/*
+ *	We enforce only one user at a time here with the open/close.
+ *	Also clear the previous interrupt data on an open, and clean
+ *	up things on a close.
+ */
+
+static int gen_rtc_open(struct inode *inode, struct file *file)
+{
+	if (gen_rtc_status & RTC_IS_OPEN)
+		return -EBUSY;
+
+	MOD_INC_USE_COUNT;
+
+	gen_rtc_status |= RTC_IS_OPEN;
+	gen_rtc_irq_data = 0;
+	irq_active = 0;
+
+	return 0;
+}
+
+static int gen_rtc_release(struct inode *inode, struct file *file)
+{
+	/*
+	 * Turn off all interrupts once the device is no longer
+	 * in use and clear the data.
+	 */
+
+	gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE);
+
+	gen_rtc_status &= ~RTC_IS_OPEN;
+	MOD_DEC_USE_COUNT;
+
+	return 0;
+}
+
+static int gen_rtc_read_proc(char *page, char **start, off_t off,
+			     int count, int *eof, void *data);
+
+
+/*
+ *	The various file operations we support.
+ */
+
+static struct file_operations gen_rtc_fops = {
+	owner:		THIS_MODULE,
+#ifdef CONFIG_GEN_RTC_X
+	read:		gen_rtc_read,
+	poll:		gen_rtc_poll,
+#endif
+	ioctl:		gen_rtc_ioctl,
+	open:		gen_rtc_open,
+	release:	gen_rtc_release
+};
+
+static struct miscdevice rtc_gen_dev =
+{
+	RTC_MINOR,
+	"rtc",
+	&gen_rtc_fops
+};
+
+int __init rtc_generic_init(void)
+{
+
+		printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION);
+
+	misc_register(&rtc_gen_dev);
+	create_proc_read_entry ("driver/rtc", 0, 0, gen_rtc_read_proc, NULL);
+
+	return 0;
+}
+
+static void __exit rtc_generic_exit(void)
+{
+	remove_proc_entry ("driver/rtc", NULL);
+	misc_deregister(&rtc_gen_dev);
+}
+
+module_init(rtc_generic_init);
+module_exit(rtc_generic_exit);
+EXPORT_NO_SYMBOLS;
+
+
+/*
+ *	Info exported via "/proc/rtc".
+ */
+
+int gen_rtc_proc_output(char *buf)
+{
+	char *p;
+	struct rtc_time tm;
+	unsigned tmp;
+	struct rtc_pll_info pll;
+
+	p = buf;
+
+	get_rtc_time(&tm);
+
+	p += sprintf(p,
+		     "rtc_time\t: %02d:%02d:%02d\n"
+		     "rtc_date\t: %04d-%02d-%02d\n"
+		     "rtc_epoch\t: %04u\n",
+		     tm.tm_hour, tm.tm_min, tm.tm_sec,
+		     tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900);
+
+	tm.tm_hour=0;tm.tm_min=0;tm.tm_sec=0;
+
+	p += sprintf(p, "alarm\t\t: ");
+	if (tm.tm_hour <= 24)
+		p += sprintf(p, "%02d:", tm.tm_hour);
+	else
+		p += sprintf(p, "**:");
+
+	if (tm.tm_min <= 59)
+		p += sprintf(p, "%02d:", tm.tm_min);
+	else
+		p += sprintf(p, "**:");
+
+	if (tm.tm_sec <= 59)
+		p += sprintf(p, "%02d\n", tm.tm_sec);
+	else
+		p += sprintf(p, "**\n");
+
+	tmp= RTC_24H ;
+	p += sprintf(p,
+		     "DST_enable\t: %s\n"
+		     "BCD\t\t: %s\n"
+		     "24hr\t\t: %s\n"
+		     "square_wave\t: %s\n"
+		     "alarm_IRQ\t: %s\n"
+		     "update_IRQ\t: %s\n"
+		     "periodic_IRQ\t: %s\n"
+		     "periodic_freq\t: %ld\n"
+		     "batt_status\t: %s\n",
+		     (tmp & RTC_DST_EN) ? "yes" : "no",
+		     (tmp & RTC_DM_BINARY) ? "no" : "yes",
+		     (tmp & RTC_24H) ? "yes" : "no",
+		     (tmp & RTC_SQWE) ? "yes" : "no",
+		     (tmp & RTC_AIE) ? "yes" : "no",
+		     irq_active ? "yes" : "no",
+		     (tmp & RTC_PIE) ? "yes" : "no",
+		     0L /* freq */,
+		     "okay" );
+	if (!get_rtc_pll(&pll))
+	    p += sprintf(p,
+			 "PLL adjustment\t: %d\n"
+			 "PLL max +ve adjustment\t: %d\n"
+			 "PLL max -ve adjustment\t: %d\n"
+			 "PLL +ve adjustment factor\t: %d\n"
+			 "PLL -ve adjustment factor\t: %d\n"
+			 "PLL frequency\t: %ld\n",
+			 pll.pll_value,
+			 pll.pll_max,
+			 pll.pll_min,
+			 pll.pll_posmult,
+			 pll.pll_negmult,
+			 pll.pll_clock);
+	return  p - buf;
+}
+
+static int gen_rtc_read_proc(char *page, char **start, off_t off,
+			     int count, int *eof, void *data)
+{
+	int len = gen_rtc_proc_output (page);
+        if (len <= off+count) *eof = 1;
+	*start = page + off;
+	len -= off;
+        if (len>count) len = count;
+        if (len<0) len = 0;
+	return len;
+}
+
+
+MODULE_AUTHOR("Richard Zidlicky");
+MODULE_LICENSE("GPL");
+
+/*
+ * Local variables:
+ * compile-command: "m68k-linux-gcc -D__KERNEL__ -I../../include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -pipe -fno-strength-reduce -ffixed-a2 -c -o genrtc.o genrtc.c"
+ * End:
+ */
+
--- linux-2.4.20/include/asm-m68k/machdep.h	Wed May 29 10:14:12 2002
+++ linux-m68k-2.4.20/include/asm-m68k/machdep.h	Mon Sep  9 13:07:29 2002
@@ -5,6 +5,7 @@
 struct kbd_repeat;
 struct mktime;
 struct rtc_time;
+struct rtc_pll_info;
 struct gendisk;
 struct buffer_head;
 
@@ -29,6 +30,9 @@
 extern void (*mach_gettod)(int *year, int *mon, int *day, int *hour,
 			   int *min, int *sec);
 extern int (*mach_hwclk)(int, struct rtc_time*);
+extern unsigned int (*mach_get_ss)(void);
+extern int (*mach_get_rtc_pll)(struct rtc_pll_info *);
+extern int (*mach_set_rtc_pll)(struct rtc_pll_info *);
 extern int (*mach_set_clock_mmss)(unsigned long);
 extern void (*mach_reset)( void );
 extern void (*mach_halt)( void );
--- linux-2.4.20/include/asm-m68k/rtc.h	Wed May 29 10:14:13 2002
+++ linux-m68k-2.4.20/include/asm-m68k/rtc.h	Sun Jan  5 15:24:28 2003
@@ -13,9 +13,8 @@
 
 #ifdef __KERNEL__
 
-#include <linux/config.h>
 #include <linux/rtc.h>
-#include <linux/delay.h>
+#include <asm/errno.h>
 #include <asm/machdep.h>
 
 #define RTC_PIE 0x40		/* periodic interrupt enable */
@@ -30,7 +29,48 @@
 #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 */
 
+static inline void get_rtc_time(struct rtc_time *time)
+{
+	/*
+	 * Only the values that we read from the RTC are set. We leave
+	 * tm_wday, tm_yday and tm_isdst untouched. Even though the
+	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
+	 * by the RTC when initially set to a non-zero value.
+	 */
+	mach_hwclk(0, time);
+}
 
+static inline int set_rtc_time(struct rtc_time *time)
+{
+	return mach_hwclk(1, time);
+}
+
+static inline unsigned int get_rtc_ss(void)
+{
+	if (mach_get_ss)
+		return mach_get_ss();
+	else{
+		struct rtc_time h;
+		
+		get_rtc_time(&h);
+		return h.tm_sec;
+	}
+}
+
+static inline int get_rtc_pll(struct rtc_pll_info *pll)
+{
+	if (mach_get_rtc_pll)
+		return mach_get_rtc_pll(pll);
+	else
+		return -EINVAL;
+}
+static inline int set_rtc_pll(struct rtc_pll_info *pll)
+{
+	if (mach_set_rtc_pll)
+		return mach_set_rtc_pll(pll);
+	else
+		return -EINVAL;
+}
 #endif /* __KERNEL__ */
 
 #endif /* _ASM__RTC_H */
--- linux-2.4.20/include/linux/rtc.h	Mon Feb 19 09:47:19 2001
+++ linux-m68k-2.4.20/include/linux/rtc.h	Sun Jan  5 15:24:28 2003
@@ -39,10 +39,32 @@
 	struct rtc_time time;	/* time the alarm is set to */
 };
 
+/*
+ * Data structure to control PLL correction some better RTC feature
+ * pll_value is used to get or set current value of correction,
+ * the rest of the struct is used to query HW capabilities.
+ * This is modeled after the RTC used in Q40/Q60 computers but
+ * should be sufficiently flexible for other devices
+ *
+ * +ve pll_value means clock will run faster by
+ *   pll_value*pll_posmult/pll_clock
+ * -ve pll_value means clock will run slower by
+ *   pll_value*pll_negmult/pll_clock
+ */ 
+
+struct rtc_pll_info {
+	int pll_ctrl;       /* placeholder for fancier control */
+	int pll_value;      /* get/set correction value */
+	int pll_max;        /* max +ve (faster) adjustment value */
+	int pll_min;        /* max -ve (slower) adjustment value */
+	int pll_posmult;    /* factor for +ve corection */
+	int pll_negmult;    /* factor for -ve corection */
+	long pll_clock;     /* base PLL frequency */
+};
 
 /*
- * ioctl calls that are permitted to the /dev/rtc interface, if 
- * CONFIG_RTC/CONFIG_EFI_RTC was enabled.
+ * ioctl calls that are permitted to the /dev/rtc interface, if
+ * any of the RTC drivers are enabled.
  */
 
 #define RTC_AIE_ON	_IO('p', 0x01)	/* Alarm int. enable on		*/
@@ -66,4 +88,6 @@
 #define RTC_WKALM_SET	_IOW('p', 0x0f, struct rtc_wkalrm)/* Set wakeup alarm*/
 #define RTC_WKALM_RD	_IOR('p', 0x10, struct rtc_wkalrm)/* Get wakeup alarm*/
 
+#define RTC_PLL_GET	_IOR('p', 0x11, struct rtc_pll_info)  /* Get PLL correction */
+#define RTC_PLL_SET	_IOW('p', 0x12, struct rtc_pll_info)  /* Set PLL correction */
 #endif /* _LINUX_RTC_H_ */

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

Generic RTC driver in 2.4.x

[Geert Uytterhoeven]

Unfortunately I didn't receive any feedback from the pa-risc and ppc people
after my previous posting last Sunday.

Alan, I'm explicitly sending it to you for inclusion in your ac tree.
I intend to send it to Marcelo after the weekend.

Changes since last Sunday:
  - fix spelling of `automatically' (from Geoffrey Lee <glee@gnupilgrims.org>)
  - misc_register() and create_proc_read_entry() can fail
    (from mikal@stillhq.com in 2.5.x)
  - create_proc_read_entry() depends on CONFIG_PROC_FS
    (from mikal@stillhq.com in 2.5.x)


The following patch adds the generic RTC driver to 2.4.20 (applies fine to
2.4.21-pre3). This driver provides a /dev/rtc-compatible interface to the real
time clock on machines without a PC-style RTC chip. It is used as the primary
RTC driver on m68k, pa-risc, and ppc. This driver is already present in 2.5.x.

Pa-risc and ppc people (any other users?), please send me your enhancements (or
just ack if none are necessary), so I can send genrtc to Marcelo.

Thanks!

 Documentation/Configure.help  |   28 ++
 arch/m68k/config.in           |    5 
 arch/m68k/kernel/m68k_ksyms.c |    5 
 arch/m68k/kernel/setup.c      |    3 
 arch/m68k/q40/config.c        |   41 +++
 drivers/char/Makefile         |    1 
 drivers/char/genrtc.c         |  533 ++++++++++++++++++++++++++++++++++++++++++
 include/asm-m68k/machdep.h    |    4 
 include/asm-m68k/rtc.h        |   44 +++
 include/linux/rtc.h           |   28 ++
 10 files changed, 687 insertions(+), 5 deletions(-)

--- linux-2.4.20/Documentation/Configure.help	Tue Oct 29 18:40:45 2002
+++ linux-genrtc-2.4.20/Documentation/Configure.help	Fri Jan 10 20:54:52 2003
@@ -18959,6 +18959,34 @@
   The module is called rtc.o. If you want to compile it as a module,
   say M here and read <file:Documentation/modules.txt>.
 
+Generic Real Time Clock Support
+CONFIG_GEN_RTC
+  If you say Y here and create a character special file /dev/rtc with
+  major number 10 and minor number 135 using mknod ("man mknod"), you
+  will get access to the real time clock (or hardware clock) built
+  into your computer.
+
+  In 2.4 and later kernels this is the only way to set and get rtc
+  time on m68k systems so it is highly recommended.
+
+  It reports status information via the file /proc/driver/rtc and its 
+  behaviour is set by various ioctls on /dev/rtc. If you enable the
+  "extended RTC operation" below it will also provide an emulation
+  for RTC_UIE which is required by some programs and may improve
+  precision in some cases.
+
+  This driver is also available as a module ( = code which can be
+  inserted in and removed from the running kernel whenever you want).
+  The module is called genrtc.o. If you want to compile it as a module,
+  say M here and read <file:Documentation/modules.txt>. To load the
+  module automatically add 'alias char-major-10-135 genrtc' to your
+  /etc/modules.conf
+
+Extended RTC operation
+CONFIG_GEN_RTC_X
+  Provides an emulation for RTC_UIE which is required by some programs 
+  and may improve precision of the generic RTC support in some cases.
+
 Tadpole ANA H8 Support
 CONFIG_H8
   The Hitachi H8/337 is a microcontroller used to deal with the power
--- linux-2.4.20/arch/m68k/config.in	Fri Sep 13 10:14:59 2002
+++ linux-genrtc-2.4.20/arch/m68k/config.in	Fri Jan 10 20:54:25 2003
@@ -517,8 +517,11 @@
    if [ "$CONFIG_SUN3" = "y" ]; then
       define_bool CONFIG_GEN_RTC y
    else
-      bool 'Generic /dev/rtc emulation' CONFIG_GEN_RTC
+      tristate 'Generic /dev/rtc emulation' CONFIG_GEN_RTC      
    fi
+fi
+if [ "$CONFIG_GEN_RTC" != "n" ]; then
+   bool '   Extended RTC operation' CONFIG_GEN_RTC_X
 fi
 bool 'Unix98 PTY support' CONFIG_UNIX98_PTYS
 if [ "$CONFIG_UNIX98_PTYS" = "y" ]; then
--- linux-2.4.20/arch/m68k/kernel/m68k_ksyms.c	Thu Jan  4 22:00:55 2001
+++ linux-genrtc-2.4.20/arch/m68k/kernel/m68k_ksyms.c	Fri Jan 10 20:54:25 2003
@@ -18,6 +18,7 @@
 #include <asm/checksum.h>
 #include <asm/hardirq.h>
 #include <asm/softirq.h>
+#include <asm/rtc.h>
 
 asmlinkage long long __ashldi3 (long long, int);
 asmlinkage long long __ashrdi3 (long long, int);
@@ -49,6 +50,10 @@
 EXPORT_SYMBOL(kernel_set_cachemode);
 #endif /* !CONFIG_SUN3 */
 EXPORT_SYMBOL(m68k_debug_device);
+EXPORT_SYMBOL(mach_hwclk);
+EXPORT_SYMBOL(mach_get_ss);
+EXPORT_SYMBOL(mach_get_rtc_pll);
+EXPORT_SYMBOL(mach_set_rtc_pll);
 EXPORT_SYMBOL(dump_fpu);
 EXPORT_SYMBOL(dump_thread);
 EXPORT_SYMBOL(strnlen);
--- linux-2.4.20/arch/m68k/kernel/setup.c	Fri Sep 13 10:15:01 2002
+++ linux-genrtc-2.4.20/arch/m68k/kernel/setup.c	Fri Jan 10 20:54:25 2003
@@ -90,6 +90,9 @@
 void (*mach_gettod) (int*, int*, int*, int*, int*, int*);
 int (*mach_hwclk) (int, struct rtc_time*) = NULL;
 int (*mach_set_clock_mmss) (unsigned long) = NULL;
+unsigned int (*mach_get_ss)(void) = NULL;
+int (*mach_get_rtc_pll)(struct rtc_pll_info *) = NULL;
+int (*mach_set_rtc_pll)(struct rtc_pll_info *) = NULL;
 void (*mach_reset)( void );
 void (*mach_halt)( void ) = NULL;
 void (*mach_power_off)( void ) = NULL;
--- linux-2.4.20/arch/m68k/q40/config.c	Fri Sep 13 10:15:02 2002
+++ linux-genrtc-2.4.20/arch/m68k/q40/config.c	Fri Jan 10 20:54:25 2003
@@ -58,7 +58,10 @@
 extern void q40_gettod (int *year, int *mon, int *day, int *hour,
                            int *min, int *sec);
 extern int q40_hwclk (int, struct rtc_time *);
+extern unsigned int q40_get_ss (void);
 extern int q40_set_clock_mmss (unsigned long);
+static int q40_get_rtc_pll(struct rtc_pll_info *pll);
+static int q40_set_rtc_pll(struct rtc_pll_info *pll);
 extern void q40_reset (void);
 void q40_halt(void);
 extern void q40_waitbut(void);
@@ -196,6 +199,9 @@
     mach_gettimeoffset   = q40_gettimeoffset; 
     mach_gettod  	 = q40_gettod;
     mach_hwclk           = q40_hwclk; 
+    mach_get_ss          = q40_get_ss; 
+    mach_get_rtc_pll     = q40_get_rtc_pll; 
+    mach_set_rtc_pll     = q40_set_rtc_pll; 
     mach_set_clock_mmss	 = q40_set_clock_mmss;
 
     mach_reset		 = q40_reset;
@@ -331,6 +337,11 @@
 	return 0;
 }
 
+unsigned int q40_get_ss()
+{
+	return bcd2bin(Q40_RTC_SECS);
+}
+
 /*
  * Set the minutes and seconds from seconds value 'nowtime'.  Fail if
  * clock is out by > 30 minutes.  Logic lifted from atari code.
@@ -362,3 +373,33 @@
 	return retval;
 }
 
+
+/* get and set PLL calibration of RTC clock */
+#define Q40_RTC_PLL_MASK ((1<<5)-1)
+#define Q40_RTC_PLL_SIGN (1<<5)
+
+static int q40_get_rtc_pll(struct rtc_pll_info *pll)
+{
+      int tmp=Q40_RTC_CTRL;
+      pll->pll_value = tmp & Q40_RTC_PLL_MASK;
+      if (tmp & Q40_RTC_PLL_SIGN) 
+	  pll->pll_value = -pll->pll_value;
+      pll->pll_max=31;
+      pll->pll_min=-31;
+      pll->pll_posmult=512;
+      pll->pll_negmult=256;
+      pll->pll_clock=125829120;
+      return 0;
+  }
+
+static int q40_set_rtc_pll(struct rtc_pll_info *pll)
+{
+  if (!pll->pll_ctrl){
+      /* the docs are a bit unclear so I am doublesetting RTC_WRITE here ... */
+      int tmp=(pll->pll_value & 31) | (pll->pll_value<0 ? 32 : 0) | Q40_RTC_WRITE;
+      Q40_RTC_CTRL |= Q40_RTC_WRITE;
+      Q40_RTC_CTRL = tmp;
+      Q40_RTC_CTRL &= ~(Q40_RTC_WRITE);
+      return 0;
+  } else return -EINVAL;
+}
--- linux-2.4.20/drivers/char/Makefile	Wed Nov 27 11:02:06 2002
+++ linux-genrtc-2.4.20/drivers/char/Makefile	Fri Jan 10 20:54:25 2003
@@ -222,6 +222,7 @@
 obj-$(CONFIG_PC110_PAD) += pc110pad.o
 obj-$(CONFIG_MK712_MOUSE) += mk712.o
 obj-$(CONFIG_RTC) += rtc.o
+obj-$(CONFIG_GEN_RTC) += genrtc.o
 obj-$(CONFIG_EFI_RTC) += efirtc.o
 ifeq ($(CONFIG_PPC),)
   obj-$(CONFIG_NVRAM) += nvram.o
--- linux-2.4.20/drivers/char/genrtc.c	Thu Jan  1 01:00:00 1970
+++ linux-genrtc-2.4.20/drivers/char/genrtc.c	Fri Jan 10 20:54:52 2003
@@ -0,0 +1,533 @@
+/*
+ *	Real Time Clock interface for q40 and other m68k machines
+ *      emulate some RTC irq capabilities in software
+ *
+ *      Copyright (C) 1999 Richard Zidlicky
+ *
+ *	based on Paul Gortmaker's rtc.c device and
+ *           Sam Creasey Generic rtc driver
+ *
+ *	This driver allows use of the real time clock (built into
+ *	nearly all computers) from user space. It exports the /dev/rtc
+ *	interface supporting various ioctl() and also the /proc/dev/rtc
+ *	pseudo-file for status information.
+ *
+ *	The ioctls can be used to set the interrupt behaviour where
+ *  supported.
+ *
+ *	The /dev/rtc interface will block on reads until an interrupt
+ *	has been received. If a RTC interrupt has already happened,
+ *	it will output an unsigned long and then block. The output value
+ *	contains the interrupt status in the low byte and the number of
+ *	interrupts since the last read in the remaining high bytes. The
+ *	/dev/rtc interface can also be used with the select(2) call.
+ *
+ *	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.
+ *
+
+ *      1.01 fix for 2.3.X                    rz@linux-m68k.org
+ *      1.02 merged with code from genrtc.c   rz@linux-m68k.org
+ *      1.03 make it more portable            zippel@linux-m68k.org
+ *      1.04 removed useless timer code       rz@linux-m68k.org
+ *      1.05 portable RTC_UIE emulation       rz@linux-m68k.org
+ *      1.06 set_rtc_time can return an error trini@kernel.crashing.org
+ */
+
+#define RTC_VERSION	"1.06"
+
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/rtc.h>
+
+/*
+ *	We sponge a minor off of the misc major. No need slurping
+ *	up another valuable major dev number for this. If you add
+ *	an ioctl, make sure you don't conflict with SPARC's RTC
+ *	ioctls.
+ */
+
+static DECLARE_WAIT_QUEUE_HEAD(gen_rtc_wait);
+
+static int gen_rtc_ioctl(struct inode *inode, struct file *file,
+		     unsigned int cmd, unsigned long arg);
+
+/*
+ *	Bits in gen_rtc_status.
+ */
+
+#define RTC_IS_OPEN		0x01	/* means /dev/rtc is in use	*/
+
+unsigned char gen_rtc_status;		/* bitmapped status byte.	*/
+unsigned long gen_rtc_irq_data;		/* our output to the world	*/
+
+/* months start at 0 now */
+unsigned char days_in_mo[] =
+{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+static int irq_active;
+
+#ifdef CONFIG_GEN_RTC_X
+struct tq_struct genrtc_task;
+static struct timer_list timer_task;
+
+static unsigned int oldsecs;
+static int lostint;
+static int tt_exp;
+
+void gen_rtc_timer(unsigned long data);
+
+static volatile int stask_active;              /* schedule_task */
+static volatile int ttask_active;              /* timer_task */
+static int stop_rtc_timers;                    /* don't requeue tasks */
+static spinlock_t gen_rtc_lock = SPIN_LOCK_UNLOCKED;
+
+/*
+ * Routine to poll RTC seconds field for change as often as posible,
+ * after first RTC_UIE use timer to reduce polling
+ */
+void genrtc_troutine(void *data)
+{
+	unsigned int tmp = get_rtc_ss();
+	
+	if (stop_rtc_timers) {
+		stask_active = 0;
+		return;
+	}
+
+	if (oldsecs != tmp){
+		oldsecs = tmp;
+
+		timer_task.function = gen_rtc_timer;
+		timer_task.expires = jiffies + HZ - (HZ/10);
+		tt_exp=timer_task.expires;
+		ttask_active=1;
+		stask_active=0;
+		add_timer(&timer_task);
+
+		gen_rtc_interrupt(0);
+	} else if (schedule_task(&genrtc_task) == 0)
+		stask_active = 0;
+}
+
+void gen_rtc_timer(unsigned long data)
+{
+	lostint = get_rtc_ss() - oldsecs ;
+	if (lostint<0) 
+		lostint = 60 - lostint;
+	if (time_after(jiffies, tt_exp))
+		printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n",
+		       jiffies-tt_exp);
+	ttask_active=0;
+	stask_active=1;
+	if ((schedule_task(&genrtc_task) == 0))
+		stask_active = 0;
+}
+
+/* 
+ * call gen_rtc_interrupt function to signal an RTC_UIE,
+ * arg is unused.
+ * Could be invoked either from a real interrupt handler or
+ * from some routine that periodically (eg 100HZ) monitors
+ * whether RTC_SECS changed
+ */
+void gen_rtc_interrupt(unsigned long arg)
+{
+	/*  We store the status in the low byte and the number of
+	 *	interrupts received since the last read in the remainder
+	 *	of rtc_irq_data.  */
+
+	gen_rtc_irq_data += 0x100;
+	gen_rtc_irq_data &= ~0xff;
+	gen_rtc_irq_data |= RTC_UIE;
+
+	if (lostint){
+		printk("genrtc: system delaying clock ticks?\n");
+		/* increment count so that userspace knows something is wrong */
+		gen_rtc_irq_data += ((lostint-1)<<8);
+		lostint = 0;
+	}
+
+	wake_up_interruptible(&gen_rtc_wait);
+}
+
+/*
+ *	Now all the various file operations that we export.
+ */
+static ssize_t gen_rtc_read(struct file *file, char *buf,
+			size_t count, loff_t *ppos)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	unsigned long data;
+	ssize_t retval;
+
+	if (count != sizeof (unsigned int) && count != sizeof (unsigned long))
+		return -EINVAL;
+
+	if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data)
+		return -EAGAIN;
+
+	add_wait_queue(&gen_rtc_wait, &wait);
+	retval = -ERESTARTSYS;
+
+	while (1) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		data = xchg(&gen_rtc_irq_data, 0);
+		if (data)
+			break;
+		if (signal_pending(current))
+			goto out;
+		schedule();
+	}
+
+	/* first test allows optimizer to nuke this case for 32-bit machines */
+	if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) {
+		unsigned int uidata = data;
+		retval = put_user(uidata, (unsigned long *)buf);
+	}
+	else {
+		retval = put_user(data, (unsigned long *)buf);
+	}
+	if (!retval)
+		retval = sizeof(unsigned long);
+ out:
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&gen_rtc_wait, &wait);
+
+	return retval;
+}
+
+static unsigned int gen_rtc_poll(struct file *file,
+				 struct poll_table_struct *wait)
+{
+	poll_wait(file, &gen_rtc_wait, wait);
+	if (gen_rtc_irq_data != 0)
+		return POLLIN | POLLRDNORM;
+	return 0;
+}
+
+#endif
+
+/*
+ * Used to disable/enable interrupts, only RTC_UIE supported
+ * We also clear out any old irq data after an ioctl() that
+ * meddles with the interrupt enable/disable bits.
+ */
+
+static inline void gen_clear_rtc_irq_bit(unsigned char bit)
+{
+#ifdef CONFIG_GEN_RTC_X
+	stop_rtc_timers = 1;
+	if (ttask_active){
+		del_timer_sync(&timer_task);
+		ttask_active = 0;
+	}
+	while (stask_active)
+		schedule();
+
+	spin_lock(&gen_rtc_lock);
+	irq_active = 0;
+	spin_unlock(&gen_rtc_lock);
+#endif
+}
+
+static inline int gen_set_rtc_irq_bit(unsigned char bit)
+{
+#ifdef CONFIG_GEN_RTC_X
+	spin_lock(&gen_rtc_lock);
+	if ( !irq_active ) {
+		irq_active = 1;
+		stop_rtc_timers = 0;
+		lostint = 0;
+		genrtc_task.routine = genrtc_troutine;
+		oldsecs = get_rtc_ss();
+		init_timer(&timer_task);
+
+		stask_active = 1;
+		if (schedule_task(&genrtc_task) == 0){
+			stask_active = 0;
+		}
+	}
+	spin_unlock(&gen_rtc_lock);
+	gen_rtc_irq_data = 0;
+	return 0;
+#else
+	return -EINVAL;
+#endif
+}
+
+static int gen_rtc_ioctl(struct inode *inode, struct file *file,
+			 unsigned int cmd, unsigned long arg)
+{
+	struct rtc_time wtime;
+	struct rtc_pll_info pll;
+
+	switch (cmd) {
+
+	case RTC_PLL_GET:
+	    if (get_rtc_pll(&pll))
+	 	    return -EINVAL;
+	    else
+		    return copy_to_user((void *)arg, &pll, sizeof pll) ? -EFAULT : 0;
+
+	case RTC_PLL_SET:
+		if (!capable(CAP_SYS_TIME))
+			return -EACCES;
+		if (copy_from_user(&pll, (struct rtc_pll_info*)arg,
+				   sizeof(pll)))
+			return -EFAULT;
+	    return set_rtc_pll(&pll);
+
+	case RTC_UIE_OFF:	/* disable ints from RTC updates.	*/
+		gen_clear_rtc_irq_bit(RTC_UIE);
+		return 0;
+
+	case RTC_UIE_ON:	/* enable ints for RTC updates.	*/
+	        return gen_set_rtc_irq_bit(RTC_UIE);
+
+	case RTC_RD_TIME:	/* Read the time/date from RTC	*/
+		/* this doesn't get week-day, who cares */
+		memset(&wtime, 0, sizeof(wtime));
+		get_rtc_time(&wtime);
+
+		return copy_to_user((void *)arg, &wtime, sizeof(wtime)) ? -EFAULT : 0;
+
+	case RTC_SET_TIME:	/* Set the RTC */
+	    {
+		int year;
+		unsigned char leap_yr;
+
+		if (!capable(CAP_SYS_TIME))
+			return -EACCES;
+
+		if (copy_from_user(&wtime, (struct rtc_time *)arg,
+				   sizeof(wtime)))
+			return -EFAULT;
+
+		year = wtime.tm_year + 1900;
+		leap_yr = ((!(year % 4) && (year % 100)) ||
+			   !(year % 400));
+
+		if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1))
+			return -EINVAL;
+
+		if (wtime.tm_mday < 0 || wtime.tm_mday >
+		    (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr)))
+			return -EINVAL;
+
+		if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
+		    wtime.tm_min < 0 || wtime.tm_min >= 60 ||
+		    wtime.tm_sec < 0 || wtime.tm_sec >= 60)
+			return -EINVAL;
+
+		return set_rtc_time(&wtime);
+	    }
+	}
+
+	return -EINVAL;
+}
+
+/*
+ *	We enforce only one user at a time here with the open/close.
+ *	Also clear the previous interrupt data on an open, and clean
+ *	up things on a close.
+ */
+
+static int gen_rtc_open(struct inode *inode, struct file *file)
+{
+	if (gen_rtc_status & RTC_IS_OPEN)
+		return -EBUSY;
+
+	MOD_INC_USE_COUNT;
+
+	gen_rtc_status |= RTC_IS_OPEN;
+	gen_rtc_irq_data = 0;
+	irq_active = 0;
+
+	return 0;
+}
+
+static int gen_rtc_release(struct inode *inode, struct file *file)
+{
+	/*
+	 * Turn off all interrupts once the device is no longer
+	 * in use and clear the data.
+	 */
+
+	gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE);
+
+	gen_rtc_status &= ~RTC_IS_OPEN;
+	MOD_DEC_USE_COUNT;
+
+	return 0;
+}
+
+static int gen_rtc_read_proc(char *page, char **start, off_t off,
+			     int count, int *eof, void *data);
+
+
+/*
+ *	The various file operations we support.
+ */
+
+static struct file_operations gen_rtc_fops = {
+	owner:		THIS_MODULE,
+#ifdef CONFIG_GEN_RTC_X
+	read:		gen_rtc_read,
+	poll:		gen_rtc_poll,
+#endif
+	ioctl:		gen_rtc_ioctl,
+	open:		gen_rtc_open,
+	release:	gen_rtc_release
+};
+
+static struct miscdevice rtc_gen_dev =
+{
+	RTC_MINOR,
+	"rtc",
+	&gen_rtc_fops
+};
+
+int __init rtc_generic_init(void)
+{
+	int retval;
+
+	printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION);
+
+	retval = misc_register(&rtc_gen_dev);
+	if(retval < 0)
+		return retval;
+
+#ifdef CONFIG_PROC_FS
+	if((create_proc_read_entry ("driver/rtc", 0, 0, gen_rtc_read_proc, NULL)) == NULL){
+		misc_deregister(&rtc_gen_dev);
+		return -ENOMEM;
+	}
+#endif
+
+	return 0;
+}
+
+static void __exit rtc_generic_exit(void)
+{
+	remove_proc_entry ("driver/rtc", NULL);
+	misc_deregister(&rtc_gen_dev);
+}
+
+module_init(rtc_generic_init);
+module_exit(rtc_generic_exit);
+EXPORT_NO_SYMBOLS;
+
+
+/*
+ *	Info exported via "/proc/rtc".
+ */
+
+int gen_rtc_proc_output(char *buf)
+{
+	char *p;
+	struct rtc_time tm;
+	unsigned tmp;
+	struct rtc_pll_info pll;
+
+	p = buf;
+
+	get_rtc_time(&tm);
+
+	p += sprintf(p,
+		     "rtc_time\t: %02d:%02d:%02d\n"
+		     "rtc_date\t: %04d-%02d-%02d\n"
+		     "rtc_epoch\t: %04u\n",
+		     tm.tm_hour, tm.tm_min, tm.tm_sec,
+		     tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900);
+
+	tm.tm_hour=0;tm.tm_min=0;tm.tm_sec=0;
+
+	p += sprintf(p, "alarm\t\t: ");
+	if (tm.tm_hour <= 24)
+		p += sprintf(p, "%02d:", tm.tm_hour);
+	else
+		p += sprintf(p, "**:");
+
+	if (tm.tm_min <= 59)
+		p += sprintf(p, "%02d:", tm.tm_min);
+	else
+		p += sprintf(p, "**:");
+
+	if (tm.tm_sec <= 59)
+		p += sprintf(p, "%02d\n", tm.tm_sec);
+	else
+		p += sprintf(p, "**\n");
+
+	tmp= RTC_24H ;
+	p += sprintf(p,
+		     "DST_enable\t: %s\n"
+		     "BCD\t\t: %s\n"
+		     "24hr\t\t: %s\n"
+		     "square_wave\t: %s\n"
+		     "alarm_IRQ\t: %s\n"
+		     "update_IRQ\t: %s\n"
+		     "periodic_IRQ\t: %s\n"
+		     "periodic_freq\t: %ld\n"
+		     "batt_status\t: %s\n",
+		     (tmp & RTC_DST_EN) ? "yes" : "no",
+		     (tmp & RTC_DM_BINARY) ? "no" : "yes",
+		     (tmp & RTC_24H) ? "yes" : "no",
+		     (tmp & RTC_SQWE) ? "yes" : "no",
+		     (tmp & RTC_AIE) ? "yes" : "no",
+		     irq_active ? "yes" : "no",
+		     (tmp & RTC_PIE) ? "yes" : "no",
+		     0L /* freq */,
+		     "okay" );
+	if (!get_rtc_pll(&pll))
+	    p += sprintf(p,
+			 "PLL adjustment\t: %d\n"
+			 "PLL max +ve adjustment\t: %d\n"
+			 "PLL max -ve adjustment\t: %d\n"
+			 "PLL +ve adjustment factor\t: %d\n"
+			 "PLL -ve adjustment factor\t: %d\n"
+			 "PLL frequency\t: %ld\n",
+			 pll.pll_value,
+			 pll.pll_max,
+			 pll.pll_min,
+			 pll.pll_posmult,
+			 pll.pll_negmult,
+			 pll.pll_clock);
+	return  p - buf;
+}
+
+static int gen_rtc_read_proc(char *page, char **start, off_t off,
+			     int count, int *eof, void *data)
+{
+	int len = gen_rtc_proc_output (page);
+        if (len <= off+count) *eof = 1;
+	*start = page + off;
+	len -= off;
+        if (len>count) len = count;
+        if (len<0) len = 0;
+	return len;
+}
+
+
+MODULE_AUTHOR("Richard Zidlicky");
+MODULE_LICENSE("GPL");
+
+/*
+ * Local variables:
+ * compile-command: "m68k-linux-gcc -D__KERNEL__ -I../../include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -pipe -fno-strength-reduce -ffixed-a2 -c -o genrtc.o genrtc.c"
+ * End:
+ */
+
--- linux-2.4.20/include/asm-m68k/machdep.h	Wed May 29 10:14:12 2002
+++ linux-genrtc-2.4.20/include/asm-m68k/machdep.h	Fri Jan 10 20:54:25 2003
@@ -5,6 +5,7 @@
 struct kbd_repeat;
 struct mktime;
 struct rtc_time;
+struct rtc_pll_info;
 struct gendisk;
 struct buffer_head;
 
@@ -29,6 +30,9 @@
 extern void (*mach_gettod)(int *year, int *mon, int *day, int *hour,
 			   int *min, int *sec);
 extern int (*mach_hwclk)(int, struct rtc_time*);
+extern unsigned int (*mach_get_ss)(void);
+extern int (*mach_get_rtc_pll)(struct rtc_pll_info *);
+extern int (*mach_set_rtc_pll)(struct rtc_pll_info *);
 extern int (*mach_set_clock_mmss)(unsigned long);
 extern void (*mach_reset)( void );
 extern void (*mach_halt)( void );
--- linux-2.4.20/include/asm-m68k/rtc.h	Wed May 29 10:14:13 2002
+++ linux-genrtc-2.4.20/include/asm-m68k/rtc.h	Fri Jan 10 20:54:25 2003
@@ -13,9 +13,8 @@
 
 #ifdef __KERNEL__
 
-#include <linux/config.h>
 #include <linux/rtc.h>
-#include <linux/delay.h>
+#include <asm/errno.h>
 #include <asm/machdep.h>
 
 #define RTC_PIE 0x40		/* periodic interrupt enable */
@@ -30,7 +29,48 @@
 #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 */
 
+static inline void get_rtc_time(struct rtc_time *time)
+{
+	/*
+	 * Only the values that we read from the RTC are set. We leave
+	 * tm_wday, tm_yday and tm_isdst untouched. Even though the
+	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
+	 * by the RTC when initially set to a non-zero value.
+	 */
+	mach_hwclk(0, time);
+}
 
+static inline int set_rtc_time(struct rtc_time *time)
+{
+	return mach_hwclk(1, time);
+}
+
+static inline unsigned int get_rtc_ss(void)
+{
+	if (mach_get_ss)
+		return mach_get_ss();
+	else{
+		struct rtc_time h;
+		
+		get_rtc_time(&h);
+		return h.tm_sec;
+	}
+}
+
+static inline int get_rtc_pll(struct rtc_pll_info *pll)
+{
+	if (mach_get_rtc_pll)
+		return mach_get_rtc_pll(pll);
+	else
+		return -EINVAL;
+}
+static inline int set_rtc_pll(struct rtc_pll_info *pll)
+{
+	if (mach_set_rtc_pll)
+		return mach_set_rtc_pll(pll);
+	else
+		return -EINVAL;
+}
 #endif /* __KERNEL__ */
 
 #endif /* _ASM__RTC_H */
--- linux-2.4.20/include/linux/rtc.h	Mon Feb 19 09:47:19 2001
+++ linux-genrtc-2.4.20/include/linux/rtc.h	Fri Jan 10 20:54:25 2003
@@ -39,10 +39,32 @@
 	struct rtc_time time;	/* time the alarm is set to */
 };
 
+/*
+ * Data structure to control PLL correction some better RTC feature
+ * pll_value is used to get or set current value of correction,
+ * the rest of the struct is used to query HW capabilities.
+ * This is modeled after the RTC used in Q40/Q60 computers but
+ * should be sufficiently flexible for other devices
+ *
+ * +ve pll_value means clock will run faster by
+ *   pll_value*pll_posmult/pll_clock
+ * -ve pll_value means clock will run slower by
+ *   pll_value*pll_negmult/pll_clock
+ */ 
+
+struct rtc_pll_info {
+	int pll_ctrl;       /* placeholder for fancier control */
+	int pll_value;      /* get/set correction value */
+	int pll_max;        /* max +ve (faster) adjustment value */
+	int pll_min;        /* max -ve (slower) adjustment value */
+	int pll_posmult;    /* factor for +ve corection */
+	int pll_negmult;    /* factor for -ve corection */
+	long pll_clock;     /* base PLL frequency */
+};
 
 /*
- * ioctl calls that are permitted to the /dev/rtc interface, if 
- * CONFIG_RTC/CONFIG_EFI_RTC was enabled.
+ * ioctl calls that are permitted to the /dev/rtc interface, if
+ * any of the RTC drivers are enabled.
  */
 
 #define RTC_AIE_ON	_IO('p', 0x01)	/* Alarm int. enable on		*/
@@ -66,4 +88,6 @@
 #define RTC_WKALM_SET	_IOW('p', 0x0f, struct rtc_wkalrm)/* Set wakeup alarm*/
 #define RTC_WKALM_RD	_IOR('p', 0x10, struct rtc_wkalrm)/* Get wakeup alarm*/
 
+#define RTC_PLL_GET	_IOR('p', 0x11, struct rtc_pll_info)  /* Get PLL correction */
+#define RTC_PLL_SET	_IOW('p', 0x12, struct rtc_pll_info)  /* Set PLL correction */
 #endif /* _LINUX_RTC_H_ */

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: Generic RTC driver in 2.4.x

[Tom Rini]

On Fri, Jan 10, 2003 at 09:05:55PM +0100, Geert Uytterhoeven wrote:
 
> Unfortunately I didn't receive any feedback from the pa-risc and ppc people
> after my previous posting last Sunday.
[snip]
> Pa-risc and ppc people (any other users?), please send me your enhancements (or
> just ack if none are necessary), so I can send genrtc to Marcelo.

Sorry I haven't spoken up before this, A simple cp of
include/asm-ppc/rtc.h (and then throwing the question
someplace) compiles a kernel correctly, and from what I recall of
getting it to work in 2.5, at that point it was all good anyhow.  So
this is fine for PPC32 as is.

-- 
Tom Rini (TR1265)
http://gate.crashing.org/~trini/

Re: Generic RTC driver in 2.4.x

[Geert Uytterhoeven]

On Thu, 30 Jan 2003, Tom Rini wrote:
> On Fri, Jan 10, 2003 at 09:05:55PM +0100, Geert Uytterhoeven wrote:
> > Unfortunately I didn't receive any feedback from the pa-risc and ppc people
> > after my previous posting last Sunday.
> [snip]
> > Pa-risc and ppc people (any other users?), please send me your enhancements (or
> > just ack if none are necessary), so I can send genrtc to Marcelo.
> 
> Sorry I haven't spoken up before this, A simple cp of
> include/asm-ppc/rtc.h (and then throwing the question
> someplace) compiles a kernel correctly, and from what I recall of
> getting it to work in 2.5, at that point it was all good anyhow.  So
> this is fine for PPC32 as is.

Note that in the mean time genrtc has changed, so I'd prefer you to at least
sent me your include/asm-ppc/rtc.h and a patch to add the question on PPC,
_after_ you have test-compiled the latest version. I'll send it to you in a
separate mail.

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