[PATCH 1/2] rtc/ia64: remove legacy efirtc driver

From: Arnd Bergmann
Date: Wed Oct 23 2019 - 11:03:39 EST


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@xxxxxxxxxxxxxxx
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
This was last discussed in early 2018 in
https://lore.kernel.org/lkml/CAK8P3a0QZNY+K+V1HG056xCerz=_L2jh5UfZ+2LWkDqkw5Zznw@xxxxxxxxxxxxxx/

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@xxxxxxxxxx>
- *
- * 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