Message-Id: <20191023150311.844123-1-arnd@arndb.de>
Date:   Wed, 23 Oct 2019 17:01:58 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Alexandre Belloni <alexandre.belloni@...tlin.com>,
        linux-rtc@...r.kernel.org, Alessandro Zummo <a.zummo@...ertech.it>,
        Arnd Bergmann <arnd@...db.de>, linux-ia64@...r.kernel.org,
        Fenghua Yu <fenghua.yu@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Stephane Eranian <eranian@...gle.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] rtc/ia64: remove legacy efirtc driver

There are two EFI RTC drivers, the original drivers/char/efirtc.c
driver and the more modern drivers/rtc/rtc-efi.c.

Both implement the same interface, but the new one does so
in a more portable way.

Move everything over to that one and remove the old one.

Cc: linux-ia64@...r.kernel.org
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: Tony Luck <tony.luck@...el.com>
Cc: Stephane Eranian <eranian@...gle.com>
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
This was last discussed in early 2018 in
https://lore.kernel.org/lkml/CAK8P3a0QZNY+K+V1HG056xCerz=_L2jh5UfZ+2LWkDqkw5Zznw@mail.gmail.com/

Nobody ever replied there, so let's try this instead.
If there is any reason to keep the driver after all,
please let us know.
---
 arch/ia64/configs/bigsur_defconfig    |   3 +-
 arch/ia64/configs/generic_defconfig   |   3 +-
 arch/ia64/configs/gensparse_defconfig |   3 +-
 arch/ia64/configs/tiger_defconfig     |   3 +-
 arch/ia64/configs/zx1_defconfig       |   3 +-
 drivers/char/Kconfig                  |   4 -
 drivers/char/Makefile                 |   1 -
 drivers/char/efirtc.c                 | 366 --------------------------
 include/linux/miscdevice.h            |   2 +-
 9 files changed, 11 insertions(+), 377 deletions(-)
 delete mode 100644 drivers/char/efirtc.c

diff --git a/arch/ia64/configs/bigsur_defconfig b/arch/ia64/configs/bigsur_defconfig
index b630bd7351c4..f3ba813a5b80 100644
--- a/arch/ia64/configs/bigsur_defconfig
+++ b/arch/ia64/configs/bigsur_defconfig
@@ -57,7 +57,8 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_8250_EXTENDED=y
 CONFIG_SERIAL_8250_SHARE_IRQ=y
 # CONFIG_HW_RANDOM is not set
-CONFIG_EFI_RTC=y
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_DRV_EFI=y
 CONFIG_I2C=y
 CONFIG_I2C_CHARDEV=y
 CONFIG_AGP=m
diff --git a/arch/ia64/configs/generic_defconfig b/arch/ia64/configs/generic_defconfig
index 661d90b3e148..cb267a07c57f 100644
--- a/arch/ia64/configs/generic_defconfig
+++ b/arch/ia64/configs/generic_defconfig
@@ -94,7 +94,8 @@ CONFIG_SERIAL_8250_NR_UARTS=6
 CONFIG_SERIAL_8250_EXTENDED=y
 CONFIG_SERIAL_8250_SHARE_IRQ=y
 # CONFIG_HW_RANDOM is not set
-CONFIG_EFI_RTC=y
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_DRV_EFI=y
 CONFIG_RAW_DRIVER=m
 CONFIG_HPET=y
 CONFIG_AGP=m
diff --git a/arch/ia64/configs/gensparse_defconfig b/arch/ia64/configs/gensparse_defconfig
index 7844e6a956a4..7e25f2f031b6 100644
--- a/arch/ia64/configs/gensparse_defconfig
+++ b/arch/ia64/configs/gensparse_defconfig
@@ -82,7 +82,8 @@ CONFIG_SERIAL_8250_NR_UARTS=6
 CONFIG_SERIAL_8250_EXTENDED=y
 CONFIG_SERIAL_8250_SHARE_IRQ=y
 # CONFIG_HW_RANDOM is not set
-CONFIG_EFI_RTC=y
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_DRV_EFI=y
 CONFIG_RAW_DRIVER=m
 CONFIG_HPET=y
 CONFIG_AGP=m
diff --git a/arch/ia64/configs/tiger_defconfig b/arch/ia64/configs/tiger_defconfig
index 1d6e2a01452b..3f486d5bdc2d 100644
--- a/arch/ia64/configs/tiger_defconfig
+++ b/arch/ia64/configs/tiger_defconfig
@@ -86,7 +86,8 @@ CONFIG_SERIAL_8250_NR_UARTS=6
 CONFIG_SERIAL_8250_EXTENDED=y
 CONFIG_SERIAL_8250_SHARE_IRQ=y
 # CONFIG_HW_RANDOM is not set
-CONFIG_EFI_RTC=y
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_DRV_EFI=y
 CONFIG_RAW_DRIVER=m
 CONFIG_HPET=y
 CONFIG_AGP=m
diff --git a/arch/ia64/configs/zx1_defconfig b/arch/ia64/configs/zx1_defconfig
index 8c92e095f8bb..70788a500448 100644
--- a/arch/ia64/configs/zx1_defconfig
+++ b/arch/ia64/configs/zx1_defconfig
@@ -69,7 +69,8 @@ CONFIG_SERIAL_8250_NR_UARTS=8
 CONFIG_SERIAL_8250_EXTENDED=y
 CONFIG_SERIAL_8250_SHARE_IRQ=y
 # CONFIG_HW_RANDOM is not set
-CONFIG_EFI_RTC=y
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_DRV_EFI=y
 CONFIG_I2C_CHARDEV=y
 CONFIG_AGP=y
 CONFIG_AGP_HP_ZX1=y
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index df0fc997dc3e..dabbf3f519c6 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -297,10 +297,6 @@ config JS_RTC
 	  To compile this driver as a module, choose M here: the
 	  module will be called js-rtc.
 
-config EFI_RTC
-	bool "EFI Real Time Clock Services"
-	depends on IA64
-
 endif # RTC_LIB
 
 config DTLK
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 7c5ea6f9df14..abe3138b1f5a 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -22,7 +22,6 @@ obj-$(CONFIG_APPLICOM)		+= applicom.o
 obj-$(CONFIG_SONYPI)		+= sonypi.o
 obj-$(CONFIG_RTC)		+= rtc.o
 obj-$(CONFIG_HPET)		+= hpet.o
-obj-$(CONFIG_EFI_RTC)		+= efirtc.o
 obj-$(CONFIG_XILINX_HWICAP)	+= xilinx_hwicap/
 obj-$(CONFIG_NVRAM)		+= nvram.o
 obj-$(CONFIG_TOSHIBA)		+= toshiba.o
diff --git a/drivers/char/efirtc.c b/drivers/char/efirtc.c
deleted file mode 100644
index 4f73064d0c6f..000000000000
--- a/drivers/char/efirtc.c
+++ /dev/null
@@ -1,366 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * EFI Time Services Driver for Linux
- *
- * Copyright (C) 1999 Hewlett-Packard Co
- * Copyright (C) 1999 Stephane Eranian <eranian@....hp.com>
- *
- * Based on skeleton from the drivers/char/rtc.c driver by P. Gortmaker
- *
- * This code provides an architected & portable interface to the real time
- * clock by using EFI instead of direct bit fiddling. The functionalities are 
- * quite different from the rtc.c driver. The only way to talk to the device 
- * is by using ioctl(). There is a /proc interface which provides the raw 
- * information.
- *
- * Please note that we have kept the API as close as possible to the
- * legacy RTC. The standard /sbin/hwclock program should work normally 
- * when used to get/set the time.
- *
- * NOTES:
- *	- Locking is required for safe execution of EFI calls with regards
- *	  to interrupts and SMP.
- *
- * TODO (December 1999):
- * 	- provide the API to set/get the WakeUp Alarm (different from the
- *	  rtc.c alarm).
- *	- SMP testing
- * 	- Add module support
- */
-
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/miscdevice.h>
-#include <linux/init.h>
-#include <linux/rtc.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/efi.h>
-#include <linux/uaccess.h>
-
-
-#define EFI_RTC_VERSION		"0.4"
-
-#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
-/*
- * EFI Epoch is 1/1/1998
- */
-#define EFI_RTC_EPOCH		1998
-
-static DEFINE_SPINLOCK(efi_rtc_lock);
-
-static long efi_rtc_ioctl(struct file *file, unsigned int cmd,
-							unsigned long arg);
-
-#define is_leap(year) \
-          ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
-
-static const unsigned short int __mon_yday[2][13] =
-{
-	/* Normal years.  */
-	{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
-	/* Leap years.  */  
-	{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
-};
-
-/*
- * returns day of the year [0-365]
- */
-static inline int
-compute_yday(efi_time_t *eft)
-{
-	/* efi_time_t.month is in the [1-12] so, we need -1 */
-	return  __mon_yday[is_leap(eft->year)][eft->month-1]+ eft->day -1;
-}
-/*
- * returns day of the week [0-6] 0=Sunday
- *
- * Don't try to provide a year that's before 1998, please !
- */
-static int
-compute_wday(efi_time_t *eft)
-{
-	int y;
-	int ndays = 0;
-
-	if ( eft->year < 1998 ) {
-		printk(KERN_ERR "efirtc: EFI year < 1998, invalid date\n");
-		return -1;
-	}
-
-	for(y=EFI_RTC_EPOCH; y < eft->year; y++ ) {
-		ndays += 365 + (is_leap(y) ? 1 : 0);
-	}
-	ndays += compute_yday(eft);
-
-	/*
-	 * 4=1/1/1998 was a Thursday
-	 */
-	return (ndays + 4) % 7;
-}
-
-static void
-convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
-{
-
-	eft->year	= wtime->tm_year + 1900;
-	eft->month	= wtime->tm_mon + 1; 
-	eft->day	= wtime->tm_mday;
-	eft->hour	= wtime->tm_hour;
-	eft->minute	= wtime->tm_min;
-	eft->second 	= wtime->tm_sec;
-	eft->nanosecond = 0; 
-	eft->daylight	= wtime->tm_isdst ? EFI_ISDST: 0;
-	eft->timezone	= EFI_UNSPECIFIED_TIMEZONE;
-}
-
-static void
-convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
-{
-	memset(wtime, 0, sizeof(*wtime));
-	wtime->tm_sec  = eft->second;
-	wtime->tm_min  = eft->minute;
-	wtime->tm_hour = eft->hour;
-	wtime->tm_mday = eft->day;
-	wtime->tm_mon  = eft->month - 1;
-	wtime->tm_year = eft->year - 1900;
-
-	/* day of the week [0-6], Sunday=0 */
-	wtime->tm_wday = compute_wday(eft);
-
-	/* day in the year [1-365]*/
-	wtime->tm_yday = compute_yday(eft);
-
-
-	switch (eft->daylight & EFI_ISDST) {
-		case EFI_ISDST:
-			wtime->tm_isdst = 1;
-			break;
-		case EFI_TIME_ADJUST_DAYLIGHT:
-			wtime->tm_isdst = 0;
-			break;
-		default:
-			wtime->tm_isdst = -1;
-	}
-}
-
-static long efi_rtc_ioctl(struct file *file, unsigned int cmd,
-							unsigned long arg)
-{
-
-	efi_status_t	status;
-	unsigned long	flags;
-	efi_time_t	eft;
-	efi_time_cap_t	cap;
-	struct rtc_time	wtime;
-	struct rtc_wkalrm __user *ewp;
-	unsigned char	enabled, pending;
-
-	switch (cmd) {
-		case RTC_UIE_ON:
-		case RTC_UIE_OFF:
-		case RTC_PIE_ON:
-		case RTC_PIE_OFF:
-		case RTC_AIE_ON:
-		case RTC_AIE_OFF:
-		case RTC_ALM_SET:
-		case RTC_ALM_READ:
-		case RTC_IRQP_READ:
-		case RTC_IRQP_SET:
-		case RTC_EPOCH_READ:
-		case RTC_EPOCH_SET:
-			return -EINVAL;
-
-		case RTC_RD_TIME:
-			spin_lock_irqsave(&efi_rtc_lock, flags);
-
-			status = efi.get_time(&eft, &cap);
-
-			spin_unlock_irqrestore(&efi_rtc_lock,flags);
-
-			if (status != EFI_SUCCESS) {
-				/* should never happen */
-				printk(KERN_ERR "efitime: can't read time\n");
-				return -EINVAL;
-			}
-
-			convert_from_efi_time(&eft, &wtime);
-
- 			return copy_to_user((void __user *)arg, &wtime,
-					    sizeof (struct rtc_time)) ? - EFAULT : 0;
-
-		case RTC_SET_TIME:
-
-			if (!capable(CAP_SYS_TIME)) return -EACCES;
-
-			if (copy_from_user(&wtime, (struct rtc_time __user *)arg,
-					   sizeof(struct rtc_time)) )
-				return -EFAULT;
-
-			convert_to_efi_time(&wtime, &eft);
-
-			spin_lock_irqsave(&efi_rtc_lock, flags);
-
-			status = efi.set_time(&eft);
-
-			spin_unlock_irqrestore(&efi_rtc_lock,flags);
-
-			return status == EFI_SUCCESS ? 0 : -EINVAL;
-
-		case RTC_WKALM_SET:
-
-			if (!capable(CAP_SYS_TIME)) return -EACCES;
-
-			ewp = (struct rtc_wkalrm __user *)arg;
-
-			if (  get_user(enabled, &ewp->enabled)
-			   || copy_from_user(&wtime, &ewp->time, sizeof(struct rtc_time)) )
-				return -EFAULT;
-
-			convert_to_efi_time(&wtime, &eft);
-
-			spin_lock_irqsave(&efi_rtc_lock, flags);
-			/*
-			 * XXX Fixme:
-			 * As of EFI 0.92 with the firmware I have on my
-			 * machine this call does not seem to work quite
-			 * right
-			 */
-			status = efi.set_wakeup_time((efi_bool_t)enabled, &eft);
-
-			spin_unlock_irqrestore(&efi_rtc_lock,flags);
-
-			return status == EFI_SUCCESS ? 0 : -EINVAL;
-
-		case RTC_WKALM_RD:
-
-			spin_lock_irqsave(&efi_rtc_lock, flags);
-
-			status = efi.get_wakeup_time((efi_bool_t *)&enabled, (efi_bool_t *)&pending, &eft);
-
-			spin_unlock_irqrestore(&efi_rtc_lock,flags);
-
-			if (status != EFI_SUCCESS) return -EINVAL;
-
-			ewp = (struct rtc_wkalrm __user *)arg;
-
-			if (  put_user(enabled, &ewp->enabled)
-			   || put_user(pending, &ewp->pending)) return -EFAULT;
-
-			convert_from_efi_time(&eft, &wtime);
-
-			return copy_to_user(&ewp->time, &wtime,
-					    sizeof(struct rtc_time)) ? -EFAULT : 0;
-	}
-	return -ENOTTY;
-}
-
-/*
- *	The various file operations we support.
- */
-
-static const struct file_operations efi_rtc_fops = {
-	.owner		= THIS_MODULE,
-	.unlocked_ioctl	= efi_rtc_ioctl,
-	.llseek		= no_llseek,
-};
-
-static struct miscdevice efi_rtc_dev= {
-	EFI_RTC_MINOR,
-	"efirtc",
-	&efi_rtc_fops
-};
-
-/*
- *	We export RAW EFI information to /proc/driver/efirtc
- */
-static int efi_rtc_proc_show(struct seq_file *m, void *v)
-{
-	efi_time_t 	eft, alm;
-	efi_time_cap_t	cap;
-	efi_bool_t	enabled, pending;	
-	unsigned long	flags;
-
-	memset(&eft, 0, sizeof(eft));
-	memset(&alm, 0, sizeof(alm));
-	memset(&cap, 0, sizeof(cap));
-
-	spin_lock_irqsave(&efi_rtc_lock, flags);
-
-	efi.get_time(&eft, &cap);
-	efi.get_wakeup_time(&enabled, &pending, &alm);
-
-	spin_unlock_irqrestore(&efi_rtc_lock,flags);
-
-	seq_printf(m,
-		   "Time           : %u:%u:%u.%09u\n"
-		   "Date           : %u-%u-%u\n"
-		   "Daylight       : %u\n",
-		   eft.hour, eft.minute, eft.second, eft.nanosecond, 
-		   eft.year, eft.month, eft.day,
-		   eft.daylight);
-
-	if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
-		seq_puts(m, "Timezone       : unspecified\n");
-	else
-		/* XXX fixme: convert to string? */
-		seq_printf(m, "Timezone       : %u\n", eft.timezone);
-		
-
-	seq_printf(m,
-		   "Alarm Time     : %u:%u:%u.%09u\n"
-		   "Alarm Date     : %u-%u-%u\n"
-		   "Alarm Daylight : %u\n"
-		   "Enabled        : %s\n"
-		   "Pending        : %s\n",
-		   alm.hour, alm.minute, alm.second, alm.nanosecond, 
-		   alm.year, alm.month, alm.day, 
-		   alm.daylight,
-		   enabled == 1 ? "yes" : "no",
-		   pending == 1 ? "yes" : "no");
-
-	if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
-		seq_puts(m, "Timezone       : unspecified\n");
-	else
-		/* XXX fixme: convert to string? */
-		seq_printf(m, "Timezone       : %u\n", alm.timezone);
-
-	/*
-	 * now prints the capabilities
-	 */
-	seq_printf(m,
-		   "Resolution     : %u\n"
-		   "Accuracy       : %u\n"
-		   "SetstoZero     : %u\n",
-		   cap.resolution, cap.accuracy, cap.sets_to_zero);
-
-	return 0;
-}
-static int __init 
-efi_rtc_init(void)
-{
-	int ret;
-	struct proc_dir_entry *dir;
-
-	printk(KERN_INFO "EFI Time Services Driver v%s\n", EFI_RTC_VERSION);
-
-	ret = misc_register(&efi_rtc_dev);
-	if (ret) {
-		printk(KERN_ERR "efirtc: can't misc_register on minor=%d\n",
-				EFI_RTC_MINOR);
-		return ret;
-	}
-
-	dir = proc_create_single("driver/efirtc", 0, NULL, efi_rtc_proc_show);
-	if (dir == NULL) {
-		printk(KERN_ERR "efirtc: can't create /proc/driver/efirtc.\n");
-		misc_deregister(&efi_rtc_dev);
-		return -1;
-	}
-	return 0;
-}
-device_initcall(efi_rtc_init);
-
-/*
-MODULE_LICENSE("GPL");
-*/
diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h
index 3247a3dc7934..4ab05916046c 100644
--- a/include/linux/miscdevice.h
+++ b/include/linux/miscdevice.h
@@ -25,7 +25,7 @@
 #define TEMP_MINOR		131	/* Temperature Sensor */
 #define APM_MINOR_DEV		134
 #define RTC_MINOR		135
-#define EFI_RTC_MINOR		136	/* EFI Time services */
+/*#define EFI_RTC_MINOR		136	was EFI Time services */
 #define VHCI_MINOR		137
 #define SUN_OPENPROM_MINOR	139
 #define DMAPI_MINOR		140	/* unused */
-- 
2.20.0

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