CHAR: Delete old and now unused M48T35 RTC driver for SGI IP27.

It was only used by this one SGI platform which recently was converted to
RTC_LIB and with RTC_LIB enabled the legacy drivers are no more selectable.

Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/configs/ip27_defconfig

···
 # CONFIG_WATCHDOG is not set
 CONFIG_HW_RANDOM=m
 # CONFIG_RTC is not set
-CONFIG_SGI_IP27_RTC=y
 # CONFIG_R3964 is not set
 # CONFIG_APPLICOM is not set
 # CONFIG_DRM is not set

arch/mips/include/asm/m48t35.h

···
-/*
- *  Registers for the SGS-Thomson M48T35 Timekeeper RAM chip
- */
-#ifndef _ASM_M48T35_H
-#define _ASM_M48T35_H
-
-#include <linux/spinlock.h>
-
-extern spinlock_t rtc_lock;
-
-struct m48t35_rtc {
-	volatile u8	pad[0x7ff8];    /* starts at 0x7ff8 */
-	volatile u8	control;
-	volatile u8	sec;
-	volatile u8	min;
-	volatile u8	hour;
-	volatile u8	day;
-	volatile u8	date;
-	volatile u8	month;
-	volatile u8	year;
-};
-
-#define M48T35_RTC_SET		0x80
-#define M48T35_RTC_STOPPED	0x80
-#define M48T35_RTC_READ		0x40
-
-#endif /* _ASM_M48T35_H */

drivers/char/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called js-rtc.
 
-config SGI_IP27_RTC
-	bool "SGI M48T35 RTC support"
-	depends on SGI_IP27
-	help
-	  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 built into your computer.
-	  Every SGI has such a clock built in. It reports status information
-	  via the file /proc/rtc and its behaviour is set by various ioctls on
-	  /dev/rtc.
-
 config GEN_RTC
 	tristate "Generic /dev/rtc emulation"
 	depends on RTC!=y && !IA64 && !ARM && !M32R && !MIPS && !SPARC && !FRV && !S390 && !SUPERH && !AVR32

drivers/char/Makefile

···
 obj-$(CONFIG_HPET)		+= hpet.o
 obj-$(CONFIG_GEN_RTC)		+= genrtc.o
 obj-$(CONFIG_EFI_RTC)		+= efirtc.o
-obj-$(CONFIG_SGI_IP27_RTC)	+= ip27-rtc.o
 obj-$(CONFIG_DS1302)		+= ds1302.o
 obj-$(CONFIG_XILINX_HWICAP)	+= xilinx_hwicap/
 ifeq ($(CONFIG_GENERIC_NVRAM),y)

drivers/char/ip27-rtc.c

···
-/*
- *	Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
- *
- *	Real Time Clock interface for Linux
- *
- *	TODO: Implement periodic interrupts.
- *
- *	Copyright (C) 2000 Silicon Graphics, Inc.
- *	Written by Ulf Carlsson ([e-mail])
- *
- *	Based on code written by Paul Gortmaker.
- *
- *	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/rtc
- *	pseudo-file for status information.
- *
- *	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.
- *
- */
-
-#define RTC_VERSION		"1.09b"
-
-#include <linux/bcd.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/smp_lock.h>
-#include <linux/types.h>
-#include <linux/miscdevice.h>
-#include <linux/ioport.h>
-#include <linux/fcntl.h>
-#include <linux/rtc.h>
-#include <linux/init.h>
-#include <linux/poll.h>
-#include <linux/proc_fs.h>
-
-#include <asm/m48t35.h>
-#include <asm/sn/ioc3.h>
-#include <asm/io.h>
-#include <asm/uaccess.h>
-#include <asm/system.h>
-#include <asm/sn/klconfig.h>
-#include <asm/sn/sn0/ip27.h>
-#include <asm/sn/sn0/hub.h>
-#include <asm/sn/sn_private.h>
-
-static long rtc_ioctl(struct file *filp, unsigned int cmd,
-			unsigned long arg);
-
-static int rtc_read_proc(char *page, char **start, off_t off,
-                         int count, int *eof, void *data);
-
-static void get_rtc_time(struct rtc_time *rtc_tm);
-
-/*
- *	Bits in rtc_status. (6 bits of room for future expansion)
- */
-
-#define RTC_IS_OPEN		0x01	/* means /dev/rtc is in use	*/
-#define RTC_TIMER_ON		0x02	/* missed irq timer active	*/
-
-static unsigned char rtc_status;	/* bitmapped status byte.	*/
-static unsigned long rtc_freq;	/* Current periodic IRQ rate	*/
-static struct m48t35_rtc *rtc;
-
-/*
- *	If this driver ever becomes modularised, it will be really nice
- *	to make the epoch retain its value across module reload...
- */
-
-static unsigned long epoch = 1970;	/* year corresponding to 0x00	*/
-
-static const unsigned char days_in_mo[] =
-{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
-
-static long rtc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
-{
-
-	struct rtc_time wtime;
-
-	switch (cmd) {
-	case RTC_RD_TIME:	/* Read the time/date from RTC	*/
-	{
-		get_rtc_time(&wtime);
-		break;
-	}
-	case RTC_SET_TIME:	/* Set the RTC */
-	{
-		struct rtc_time rtc_tm;
-		unsigned char mon, day, hrs, min, sec, leap_yr;
-		unsigned int yrs;
-
-		if (!capable(CAP_SYS_TIME))
-			return -EACCES;
-
-		if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
-				   sizeof(struct rtc_time)))
-			return -EFAULT;
-
-		yrs = rtc_tm.tm_year + 1900;
-		mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
-		day = rtc_tm.tm_mday;
-		hrs = rtc_tm.tm_hour;
-		min = rtc_tm.tm_min;
-		sec = rtc_tm.tm_sec;
-
-		if (yrs < 1970)
-			return -EINVAL;
-
-		leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
-
-		if ((mon > 12) || (day == 0))
-			return -EINVAL;
-
-		if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
-			return -EINVAL;
-
-		if ((hrs >= 24) || (min >= 60) || (sec >= 60))
-			return -EINVAL;
-
-		if ((yrs -= epoch) > 255)    /* They are unsigned */
-			return -EINVAL;
-
-		if (yrs > 169)
-			return -EINVAL;
-
-		if (yrs >= 100)
-			yrs -= 100;
-
-		sec = bin2bcd(sec);
-		min = bin2bcd(min);
-		hrs = bin2bcd(hrs);
-		day = bin2bcd(day);
-		mon = bin2bcd(mon);
-		yrs = bin2bcd(yrs);
-
-		spin_lock_irq(&rtc_lock);
-		rtc->control |= M48T35_RTC_SET;
-		rtc->year = yrs;
-		rtc->month = mon;
-		rtc->date = day;
-		rtc->hour = hrs;
-		rtc->min = min;
-		rtc->sec = sec;
-		rtc->control &= ~M48T35_RTC_SET;
-		spin_unlock_irq(&rtc_lock);
-
-		return 0;
-	}
-	default:
-		return -EINVAL;
-	}
-	return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
-}
-
-/*
- *	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 rtc_open(struct inode *inode, struct file *file)
-{
-	lock_kernel();
-	spin_lock_irq(&rtc_lock);
-
-	if (rtc_status & RTC_IS_OPEN) {
-		spin_unlock_irq(&rtc_lock);
-		unlock_kernel();
-		return -EBUSY;
-	}
-
-	rtc_status |= RTC_IS_OPEN;
-	spin_unlock_irq(&rtc_lock);
-	unlock_kernel();
-
-	return 0;
-}
-
-static int rtc_release(struct inode *inode, struct file *file)
-{
-	/*
-	 * Turn off all interrupts once the device is no longer
-	 * in use, and clear the data.
-	 */
-
-	spin_lock_irq(&rtc_lock);
-	rtc_status &= ~RTC_IS_OPEN;
-	spin_unlock_irq(&rtc_lock);
-
-	return 0;
-}
-
-/*
- *	The various file operations we support.
- */
-
-static const struct file_operations rtc_fops = {
-	.owner		= THIS_MODULE,
-	.unlocked_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)
-{
-	rtc = (struct m48t35_rtc *)
-	(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + IOC3_BYTEBUS_DEV0);
-
-	printk(KERN_INFO "Real Time Clock Driver v%s\n", RTC_VERSION);
-	if (misc_register(&rtc_dev)) {
-		printk(KERN_ERR "rtc: cannot register misc device.\n");
-		return -ENODEV;
-	}
-	if (!create_proc_read_entry("driver/rtc", 0, NULL, rtc_read_proc, NULL)) {
-		printk(KERN_ERR "rtc: cannot create /proc/rtc.\n");
-		misc_deregister(&rtc_dev);
-		return -ENOENT;
-	}
-
-	rtc_freq = 1024;
-
-	return 0;
-}
-
-static void __exit rtc_exit (void)
-{
-	/* interrupts and timer disabled at this point by rtc_release */
-
-	remove_proc_entry ("rtc", NULL);
-	misc_deregister(&rtc_dev);
-}
-
-module_init(rtc_init);
-module_exit(rtc_exit);
-
-/*
- *	Info exported via "/proc/rtc".
- */
-
-static int rtc_get_status(char *buf)
-{
-	char *p;
-	struct rtc_time tm;
-
-	/*
-	 * Just emulate the standard /proc/rtc
-	 */
-
-	p = buf;
-
-	get_rtc_time(&tm);
-
-	/*
-	 * 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"
-		     "24hr\t\t: yes\n",
-		     tm.tm_hour, tm.tm_min, tm.tm_sec,
-		     tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
-
-	return  p - buf;
-}
-
-static int rtc_read_proc(char *page, char **start, off_t off,
-                                 int count, int *eof, void *data)
-{
-        int len = rtc_get_status(page);
-        if (len <= off+count) *eof = 1;
-        *start = page + off;
-        len -= off;
-        if (len>count) len = count;
-        if (len<0) len = 0;
-        return len;
-}
-
-static void get_rtc_time(struct rtc_time *rtc_tm)
-{
-	/*
-	 * Do we need to wait for the last update to finish?
-	 */
-
-	/*
-	 * 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.
-	 */
-	spin_lock_irq(&rtc_lock);
-	rtc->control |= M48T35_RTC_READ;
-	rtc_tm->tm_sec = rtc->sec;
-	rtc_tm->tm_min = rtc->min;
-	rtc_tm->tm_hour = rtc->hour;
-	rtc_tm->tm_mday = rtc->date;
-	rtc_tm->tm_mon = rtc->month;
-	rtc_tm->tm_year = rtc->year;
-	rtc->control &= ~M48T35_RTC_READ;
-	spin_unlock_irq(&rtc_lock);
-
-	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
-	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
-	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
-	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
-	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
-	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
-
-	/*
-	 * Account for differences between how the RTC uses the values
-	 * and how they are defined in a struct rtc_time;
-	 */
-	if ((rtc_tm->tm_year += (epoch - 1900)) <= 69)
-		rtc_tm->tm_year += 100;
-
-	rtc_tm->tm_mon--;
-}