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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/rtc/rtc-efi.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'drivers/rtc/rtc-efi.c')
-rw-r--r--drivers/rtc/rtc-efi.c224
1 files changed, 224 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
new file mode 100644
index 000000000..b4f44999e
--- /dev/null
+++ b/drivers/rtc/rtc-efi.c
@@ -0,0 +1,224 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * rtc-efi: RTC Class Driver for EFI-based systems
+ *
+ * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
+ *
+ * Author: dann frazier <dannf@dannf.org>
+ * Based on efirtc.c by Stephane Eranian
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/stringify.h>
+#include <linux/time.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/efi.h>
+
+#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
+
+/*
+ * 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 rtc_year_days(eft->day, eft->month - 1, eft->year);
+}
+
+/*
+ * returns day of the week [0-6] 0=Sunday
+ */
+static int
+compute_wday(efi_time_t *eft, int yday)
+{
+ int ndays = eft->year * (365 % 7)
+ + (eft->year - 1) / 4
+ - (eft->year - 1) / 100
+ + (eft->year - 1) / 400
+ + yday;
+
+ /*
+ * 1/1/0000 may or may not have been a Sunday (if it ever existed at
+ * all) but assuming it was makes this calculation work correctly.
+ */
+ return ndays % 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 bool
+convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
+{
+ memset(wtime, 0, sizeof(*wtime));
+
+ if (eft->second >= 60)
+ return false;
+ wtime->tm_sec = eft->second;
+
+ if (eft->minute >= 60)
+ return false;
+ wtime->tm_min = eft->minute;
+
+ if (eft->hour >= 24)
+ return false;
+ wtime->tm_hour = eft->hour;
+
+ if (!eft->day || eft->day > 31)
+ return false;
+ wtime->tm_mday = eft->day;
+
+ if (!eft->month || eft->month > 12)
+ return false;
+ wtime->tm_mon = eft->month - 1;
+
+ if (eft->year < 1900 || eft->year > 9999)
+ return false;
+ wtime->tm_year = eft->year - 1900;
+
+ /* day in the year [1-365]*/
+ wtime->tm_yday = compute_yday(eft);
+
+ /* day of the week [0-6], Sunday=0 */
+ wtime->tm_wday = compute_wday(eft, wtime->tm_yday);
+
+ 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;
+ }
+
+ return true;
+}
+
+static int efi_read_time(struct device *dev, struct rtc_time *tm)
+{
+ efi_status_t status;
+ efi_time_t eft;
+ efi_time_cap_t cap;
+
+ status = efi.get_time(&eft, &cap);
+
+ if (status != EFI_SUCCESS) {
+ /* should never happen */
+ dev_err_once(dev, "can't read time\n");
+ return -EINVAL;
+ }
+
+ if (!convert_from_efi_time(&eft, tm))
+ return -EIO;
+
+ return 0;
+}
+
+static int efi_set_time(struct device *dev, struct rtc_time *tm)
+{
+ efi_status_t status;
+ efi_time_t eft;
+
+ convert_to_efi_time(tm, &eft);
+
+ status = efi.set_time(&eft);
+
+ return status == EFI_SUCCESS ? 0 : -EINVAL;
+}
+
+static int efi_procfs(struct device *dev, struct seq_file *seq)
+{
+ efi_time_t eft;
+ efi_time_cap_t cap;
+
+ memset(&eft, 0, sizeof(eft));
+ memset(&cap, 0, sizeof(cap));
+
+ efi.get_time(&eft, &cap);
+
+ seq_printf(seq,
+ "Time\t\t: %u:%u:%u.%09u\n"
+ "Date\t\t: %u-%u-%u\n"
+ "Daylight\t: %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(seq, "Timezone\t: unspecified\n");
+ else
+ /* XXX fixme: convert to string? */
+ seq_printf(seq, "Timezone\t: %u\n", eft.timezone);
+
+ /*
+ * now prints the capabilities
+ */
+ seq_printf(seq,
+ "Resolution\t: %u\n"
+ "Accuracy\t: %u\n"
+ "SetstoZero\t: %u\n",
+ cap.resolution, cap.accuracy, cap.sets_to_zero);
+
+ return 0;
+}
+
+static const struct rtc_class_ops efi_rtc_ops = {
+ .read_time = efi_read_time,
+ .set_time = efi_set_time,
+ .proc = efi_procfs,
+};
+
+static int __init efi_rtc_probe(struct platform_device *dev)
+{
+ struct rtc_device *rtc;
+ efi_time_t eft;
+ efi_time_cap_t cap;
+
+ /* First check if the RTC is usable */
+ if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
+ return -ENODEV;
+
+ rtc = devm_rtc_allocate_device(&dev->dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ platform_set_drvdata(dev, rtc);
+
+ rtc->ops = &efi_rtc_ops;
+ clear_bit(RTC_FEATURE_ALARM, rtc->features);
+
+ device_init_wakeup(&dev->dev, true);
+
+ return devm_rtc_register_device(rtc);
+}
+
+static struct platform_driver efi_rtc_driver = {
+ .driver = {
+ .name = "rtc-efi",
+ },
+};
+
+module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
+
+MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("EFI RTC driver");
+MODULE_ALIAS("platform:rtc-efi");