In last round of RFC, I heard several voices:
. some similar ones are already there, drivers/macintosh/rtc.c. But we can't
really use it unless we modified it to interface with MIPS kernel rtc routines
and fix a couple of other minor stuff. Even then it seems a little
politically incorrect to use a Macintosh driver for MIPS boards. :-)
. Tom Rini wants to do a universal RTC driver. Cool, we need to wait.
Meanwhile I also heard people who want the driver. So it seems to me it makes
sense to check in this driver. Right now there are nine boards using
NEW_TIME_C, which can benefit from this driver immediately. I expect more
boards will use NEW_TIME_C soon.
So here is my updated patch. Please consider for applying.
Jun
diff -Nru linux/Documentation/Configure.help.orig linux/Documentation/Configure.help
--- linux/Documentation/Configure.help.orig Tue Nov 6 11:25:32 2001
+++ linux/Documentation/Configure.help Tue Nov 27 11:05:10 2001
@@ -15163,6 +15163,17 @@
#EFI Real Time Clock Services
#CONFIG_EFI_RTC
+Generic MIPS RTC Support
+CONFIG_MIPS_RTC
+
+ If your machine is a MIPS machine, this option provides a simple,
+ generic RTC driver for /dev/rtc device. It only implements two IOCTL
+ operations of the standard PC RTC driver: RTC_RD_TIME and RTC_SET_TIME.
+ It is sufficient to run hwclock program.
+
+ You should say Y here if there is no machine-specific RTC driver for your
+ MIPS machine but you do want a simple RTC driver for your RTC device.
+
Tadpole ANA H8 Support
CONFIG_H8
The Hitachi H8/337 is a microcontroller used to deal with the power
diff -Nru linux/drivers/char/Config.in.orig linux/drivers/char/Config.in
--- linux/drivers/char/Config.in.orig Tue Nov 27 11:03:11 2001
+++ linux/drivers/char/Config.in Tue Nov 27 11:05:10 2001
@@ -213,6 +213,9 @@
if [ "$CONFIG_OBSOLETE" = "y" -a "$CONFIG_ALPHA_BOOK1" = "y" ]; then
bool 'Tadpole ANA H8 Support' CONFIG_H8
fi
+if [ "$CONFIG_MIPS" = "y" -a "$CONFIG_NEW_TIME_C" = "y" ]; then
+ tristate 'Generic MIPS RTC Support' CONFIG_MIPS_RTC
+fi
tristate 'Double Talk PC internal speech card support' CONFIG_DTLK
tristate 'Siemens R3964 line discipline' CONFIG_R3964
diff -Nru linux/drivers/char/Makefile.orig linux/drivers/char/Makefile
--- linux/drivers/char/Makefile.orig Tue Nov 27 11:03:12 2001
+++ linux/drivers/char/Makefile Tue Nov 27 11:05:10 2001
@@ -196,6 +196,7 @@
obj-$(CONFIG_PC110_PAD) += pc110pad.o
obj-$(CONFIG_RTC) += rtc.o
obj-$(CONFIG_EFI_RTC) += efirtc.o
+obj-$(CONFIG_MIPS_RTC) += mips_rtc.o
ifeq ($(CONFIG_PPC),)
obj-$(CONFIG_NVRAM) += nvram.o
endif
diff -Nru linux/drivers/char/mips_rtc.c.orig linux/drivers/char/mips_rtc.c
--- linux/drivers/char/mips_rtc.c.orig Tue Nov 27 11:05:10 2001
+++ linux/drivers/char/mips_rtc.c Tue Nov 27 11:05:10 2001
@@ -0,0 +1,221 @@
+/*
+ * A simple generic Real Time Clock interface for Linux/MIPS
+ *
+ * Copyright (C) 1996 Paul Gortmaker
+ *
+ * Copyright (C) 2001 Monta Vista Software
+ * Author Jun Sun, jsun@mvista.com or jsun@junsun.net
+ *
+ * This is a simple generic RTC driver for MIPS boards configured
+ * with CONFIG_NEW_TIME_C. For now, it makes use of the two
+ * abstract kernel RTC functions introduced in include/asm-mips/time.h:
+ *
+ * extern unsigned long (*rtc_get_time)(void);
+ * extern int (*rtc_set_time)(unsigned long);
+ *
+ * It uses the same protocol as the original drivers/char/rtc.c driver,
+ * but only implements two ioctls: RTC_RD_TIME and RTC_SET_TIME.
+ *
+ * TODO :
+ *
+ * 1. we can extend the null rtc ops defined in arch/mips/time.c to
+ * at least record the elapsed time (by recording/checking jiffies)
+ * This way RTC_RD_TIME and RTC_SET_TIME will make more sense.
+ * (Maybe not. A machine without a real RTC is broken anymore.
+ * Just a thought.)
+ *
+ * 2. If we make use of timer bh, we can emulate many RTC functions
+ * such as RTC alarm interrupt, periodic interrupts, etc.
+ *
+ * 3. It is possible to extend the kernel RTC abstractions to more
+ * than two functions, so that perhaps we can implement more
+ * full-featured RTC driver and also have a better abstraction
+ * to support more RTC hardware than the original RTC driver.
+ * It needs to be done very carefully.
+ *
+ * Change Log :
+ * v1.0 - [jsun] initial version
+ */
+
+#define RTC_VERSION "1.0"
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+/*
+ * Check machine
+ */
+#if !defined(CONFIG_MIPS) || !defined(CONFIG_NEW_TIME_C)
+#error "This driver is for MIPS machines with CONFIG_NEW_TIME_C defined"
+#endif
+
+#include <asm/time.h>
+
+static unsigned long rtc_status = 0; /* bitmapped status byte. */
+
+static int rtc_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data);
+
+
+#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
+
+static spinlock_t rtc_lock;
+
+static int
+rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct rtc_time rtc_tm;
+ ulong curr_time;
+
+ switch (cmd) {
+ case RTC_RD_TIME: /* Read the time/date from RTC */
+ curr_time = rtc_get_time();
+ to_tm(curr_time, &rtc_tm);
+ rtc_tm.tm_year -= 1900;
+ return copy_to_user((void *) arg, &rtc_tm, sizeof(rtc_tm)) ?
+ -EFAULT : 0;
+ case RTC_SET_TIME: /* Set the RTC */
+ if (!capable(CAP_SYS_TIME))
+ return -EACCES;
+
+ if (copy_from_user(&rtc_tm,
+ (struct rtc_time *) arg,
+ sizeof(struct rtc_time)))
+ return -EFAULT;
+
+ curr_time = mktime(rtc_tm.tm_year + 1900,
+ rtc_tm.tm_mon + 1, /* tm_mon starts from 0 */
+ rtc_tm.tm_mday,
+ rtc_tm.tm_hour,
+ rtc_tm.tm_min,
+ rtc_tm.tm_sec);
+ return rtc_set_time(curr_time);
+ default:
+ return -EINVAL;
+ }
+}
+
+/* We use rtc_lock to protect against concurrent opens. So the BKL is not
+ * needed here. Or anywhere else in this driver. */
+static int rtc_open(struct inode *inode, struct file *file)
+{
+ spin_lock_irq(&rtc_lock);
+
+ if (rtc_status & RTC_IS_OPEN) {
+ spin_unlock_irq(&rtc_lock);
+ return -EBUSY;
+ }
+
+ rtc_status |= RTC_IS_OPEN;
+
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+}
+
+static int rtc_release(struct inode *inode, struct file *file)
+{
+ spin_lock_irq(&rtc_lock);
+ rtc_status &= ~RTC_IS_OPEN;
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+}
+
+/*
+ * The various file operations we support.
+ */
+
+static struct file_operations rtc_fops = {
+ owner:THIS_MODULE,
+ llseek:no_llseek,
+ ioctl:rtc_ioctl,
+ open:rtc_open,
+ release:rtc_release,
+};
+
+static struct miscdevice rtc_dev = {
+ RTC_MINOR,
+ "rtc",
+ &rtc_fops
+};
+
+static int __init rtc_init(void)
+{
+
+ misc_register(&rtc_dev);
+ create_proc_read_entry("driver/rtc", 0, 0, rtc_read_proc, NULL);
+
+ printk(KERN_INFO "Generic MIPS RTC Driver v" RTC_VERSION "\n");
+
+ return 0;
+}
+
+static void __exit rtc_exit(void)
+{
+ remove_proc_entry("driver/rtc", NULL);
+ misc_deregister(&rtc_dev);
+
+}
+
+module_init(rtc_init);
+module_exit(rtc_exit);
+EXPORT_NO_SYMBOLS;
+
+/*
+ * Info exported via "/proc/driver/rtc".
+ */
+
+static int rtc_proc_output(char *buf)
+{
+ char *p;
+ struct rtc_time tm;
+ unsigned long curr_time;
+
+ curr_time = rtc_get_time();
+ to_tm(curr_time, &tm);
+
+ p = buf;
+
+ /*
+ * There is no way to tell if the luser has the RTC set for local
+ * time or for Universal Standard Time (GMT). Probably local though.
+ */
+ p += sprintf(p,
+ "rtc_time\t: %02d:%02d:%02d\n"
+ "rtc_date\t: %04d-%02d-%02d\n"
+ "rtc_epoch\t: %04lu\n",
+ tm.tm_hour, tm.tm_min, tm.tm_sec,
+ tm.tm_year, tm.tm_mon + 1, tm.tm_mday, 0L);
+
+ return p - buf;
+}
+
+static int rtc_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len = 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("Jun Sun");
+MODULE_LICENSE("GPL");
