Merge tag 'rtc-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "Here is the pull-request for the RTC subsystem for 4.13.

  Subsystem:

   - expose non volatile RAM using nvmem instead of open coding in many
     drivers. Unfortunately, this option has to be enabled by default to
     not break existing users.

   - rtctest can now test for cutoff dates, showing when an RTC will
     start failing to properly save time and date.

   - new RTC registration functions to remove race conditions in drivers

  Newly supported RTCs:

   - Broadcom STB wake-timer

   - Epson RX8130CE

   - Maxim IC DS1308

   - STMicroelectronics STM32H7

  Drivers:

   - ds1307: use regmap, use nvmem, more cleanups

   - ds3232: temperature reading support

   - gemini: renamed to ftrtc010

   - m41t80: use CCF to expose the clock

   - rv8803: use nvmem

   - s3c: many cleanups

   - st-lpc: fix y2106 bug"

* tag 'rtc-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (51 commits)
  rtc: Remove wrong deprecation comment
  nvmem: include linux/err.h from header
  rtc: st-lpc: make it robust against y2038/2106 bug
  rtc: rtctest: add check for problematic dates
  tools: timer: add rtctest_setdate
  rtc: ds1307: remove ds1307_remove
  rtc: ds1307: use generic nvmem
  rtc: ds1307: switch to rtc_register_device
  rtc: rv8803: remove rv8803_remove
  rtc: rv8803: use generic nvmem support
  rtc: rv8803: switch to rtc_register_device
  rtc: add generic nvmem support
  rtc: at91rm9200: remove race condition
  rtc: introduce new registration method
  rtc: class separate id allocation from registration
  rtc: class separate device allocation from registration
  rtc: stm32: add STM32H7 RTC support
  dt-bindings: rtc: stm32: add support for STM32H7
  rtc: ds1307: add ds1308 variant
  rtc: ds3232: add temperature support
  ...

1 files changed, 113 insertions, 0 deletions

diff --git a/drivers/rtc/nvmem.c b/drivers/rtc/nvmem.c
new file mode 100644
index 000000000000..8567b4ed9ac6
--- /dev/null
+++ b/drivers/rtc/nvmem.c
@@ -0,0 +1,113 @@
+/*
+ * RTC subsystem, nvmem interface
+ *
+ * Copyright (C) 2017 Alexandre Belloni
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/rtc.h>
+#include <linux/sysfs.h>
+
+#include "rtc-core.h"
+
+/*
+ * Deprecated ABI compatibility, this should be removed at some point
+ */
+
+static const char nvram_warning[] = "Deprecated ABI, please use nvmem";
+
+static ssize_t
+rtc_nvram_read(struct file *filp, struct kobject *kobj,
+	       struct bin_attribute *attr,
+	       char *buf, loff_t off, size_t count)
+{
+	struct rtc_device *rtc = attr->private;
+
+	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
+
+	return nvmem_device_read(rtc->nvmem, off, count, buf);
+}
+
+static ssize_t
+rtc_nvram_write(struct file *filp, struct kobject *kobj,
+		struct bin_attribute *attr,
+		char *buf, loff_t off, size_t count)
+{
+	struct rtc_device *rtc = attr->private;
+
+	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
+
+	return nvmem_device_write(rtc->nvmem, off, count, buf);
+}
+
+static int rtc_nvram_register(struct rtc_device *rtc)
+{
+	int err;
+
+	rtc->nvram = devm_kzalloc(rtc->dev.parent,
+				sizeof(struct bin_attribute),
+				GFP_KERNEL);
+	if (!rtc->nvram)
+		return -ENOMEM;
+
+	rtc->nvram->attr.name = "nvram";
+	rtc->nvram->attr.mode = 0644;
+	rtc->nvram->private = rtc;
+
+	sysfs_bin_attr_init(rtc->nvram);
+
+	rtc->nvram->read = rtc_nvram_read;
+	rtc->nvram->write = rtc_nvram_write;
+	rtc->nvram->size = rtc->nvmem_config->size;
+
+	err = sysfs_create_bin_file(&rtc->dev.parent->kobj,
+				    rtc->nvram);
+	if (err) {
+		devm_kfree(rtc->dev.parent, rtc->nvram);
+		rtc->nvram = NULL;
+	}
+
+	return err;
+}
+
+static void rtc_nvram_unregister(struct rtc_device *rtc)
+{
+	sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram);
+}
+
+/*
+ * New ABI, uses nvmem
+ */
+void rtc_nvmem_register(struct rtc_device *rtc)
+{
+	if (!rtc->nvmem_config)
+		return;
+
+	rtc->nvmem_config->dev = &rtc->dev;
+	rtc->nvmem_config->owner = rtc->owner;
+	rtc->nvmem = nvmem_register(rtc->nvmem_config);
+	if (IS_ERR_OR_NULL(rtc->nvmem))
+		return;
+
+	/* Register the old ABI */
+	if (rtc->nvram_old_abi)
+		rtc_nvram_register(rtc);
+}
+
+void rtc_nvmem_unregister(struct rtc_device *rtc)
+{
+	if (IS_ERR_OR_NULL(rtc->nvmem))
+		return;
+
+	/* unregister the old ABI */
+	if (rtc->nvram)
+		rtc_nvram_unregister(rtc);
+
+	nvmem_unregister(rtc->nvmem);
+}