Merge tag 'rtc-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "There are two new drivers this cycle. There is also support for a
  negative offset for RTCs that have been shipped with a date set using
  an epoch that is before 1970. This unfortunately happens with some
  products that ship with a vendor kernel and an out of tree driver.

  Core:
   - support negative offsets for RTCs that have shipped with an epoch
     earlier than 1970

  New drivers:
   - NXP S32G2/S32G3
   - Sophgo CV1800

  Drivers:
   - loongson: fix missing alarm notifications for ACPI
   - m41t80: kickstart ocillator upon failure
   - mt6359: mt6357 support
   - pcf8563: fix wrong alarm register
   - sh: cleanups"

* tag 'rtc-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (39 commits)
  rtc: mt6359: Add mt6357 support
  rtc: test: Test date conversion for dates starting in 1900
  rtc: test: Also test time and wday outcome of rtc_time64_to_tm()
  rtc: test: Emit the seconds-since-1970 value instead of days-since-1970
  rtc: Fix offset calculation for .start_secs < 0
  rtc: Make rtc_time64_to_tm() support dates before 1970
  rtc: pcf8563: fix wrong alarm register
  rtc: rzn1: support input frequencies other than 32768Hz
  rtc: rzn1: Disable controller before initialization
  dt-bindings: rtc: rzn1: add optional second clock
  rtc: m41t80: reduce verbosity
  rtc: m41t80: kickstart ocillator upon failure
  rtc: s32g: add NXP S32G2/S32G3 SoC support
  dt-bindings: rtc: add schema for NXP S32G2/S32G3 SoCs
  dt-bindings: at91rm9260-rtt: add microchip,sama7d65-rtt
  dt-bindings: rtc: at91rm9200: add microchip,sama7d65-rtc
  rtc: loongson: Add missing alarm notifications for ACPI RTC events
  rtc: sophgo: add rtc support for Sophgo CV1800 SoC
  rtc: stm32: drop unused module alias
  rtc: s3c: drop unused module alias
  ...

Author: torvalds

Documentation/devicetree/bindings/rtc/atmel,at91rm9200-rtc.yaml

@@ -23,7 +23,9 @@ properties:
           - microchip,sam9x60-rtc
           - microchip,sama7g5-rtc
       - items:
-          - const: microchip,sam9x7-rtc
+          - enum:
+              - microchip,sam9x7-rtc
+              - microchip,sama7d65-rtc
           - const: microchip,sam9x60-rtc
 
   reg:

Documentation/devicetree/bindings/rtc/atmel,at91sam9260-rtt.yaml

@@ -22,6 +22,7 @@ properties:
           - enum:
               - microchip,sam9x60-rtt
               - microchip,sam9x7-rtt
+              - microchip,sama7d65-rtt
           - const: atmel,at91sam9260-rtt
       - items:
           - const: microchip,sama7g5-rtt

Documentation/devicetree/bindings/rtc/nxp,s32g-rtc.yaml

@@ -0,0 +1,72 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/nxp,s32g-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP S32G2/S32G3 Real Time Clock (RTC)
+
+maintainers:
+  - Bogdan Hamciuc <[email protected]>
+  - Ciprian Marian Costea <[email protected]>
+
+description:
+  RTC hardware module present on S32G2/S32G3 SoCs is used as a wakeup source.
+  It is not kept alive during system reset and it is not battery-powered.
+
+allOf:
+  - $ref: rtc.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - nxp,s32g2-rtc
+      - items:
+          - const: nxp,s32g3-rtc
+          - const: nxp,s32g2-rtc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: ipg clock drives the access to the RTC iomapped registers
+      - description: Clock source for the RTC module. Can be selected between
+          4 different clock sources using an integrated hardware mux.
+          On S32G2/S32G3 SoCs, 'source0' is the SIRC clock (~32KHz) and it is
+          available during standby and runtime. 'source1' is reserved and cannot
+          be used. 'source2' is the FIRC clock and it is only available during
+          runtime providing a better resolution (~48MHz). 'source3' is an external
+          RTC clock source which can be additionally added in hardware.
+
+  clock-names:
+    items:
+      - const: ipg
+      - enum: [ source0, source1, source2, source3 ]
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    rtc@40060000 {
+        compatible = "nxp,s32g3-rtc",
+                     "nxp,s32g2-rtc";
+        reg = <0x40060000 0x1000>;
+        interrupts = <GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clks 54>, <&clks 55>;
+        clock-names = "ipg", "source0";
+    };

Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml

@@ -55,6 +55,12 @@ properties:
     description:
       RTC alarm is not owned by the OS
 
+  qcom,uefi-rtc-info:
+    type: boolean
+    description:
+      RTC offset is stored as a four-byte GPS time offset in a 12-byte UEFI
+      variable 882f8c2b-9646-435f-8de5-f208ff80c1bd-RTCInfo
+
   wakeup-source: true
 
 required:

Documentation/devicetree/bindings/rtc/renesas,rzn1-rtc.yaml

@@ -33,10 +33,14 @@ properties:
       - const: pps
 
   clocks:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
 
   clock-names:
-    const: hclk
+    minItems: 1
+    items:
+      - const: hclk
+      - const: xtal
 
   power-domains:
     maxItems: 1

drivers/rtc/Kconfig

@@ -1388,6 +1388,18 @@ config RTC_DRV_ASM9260
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-asm9260.
 
+config RTC_DRV_CV1800
+	tristate "Sophgo CV1800 RTC"
+	depends on SOPHGO_CV1800_RTCSYS || COMPILE_TEST
+	select MFD_SYSCON
+	select REGMAP
+	help
+	  If you say yes here you get support the RTC driver for Sophgo CV1800
+	  series SoC.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called rtc-cv1800.
+
 config RTC_DRV_DIGICOLOR
 	tristate "Conexant Digicolor RTC"
 	depends on ARCH_DIGICOLOR || COMPILE_TEST
@@ -2088,12 +2100,23 @@ config RTC_DRV_AMLOGIC_A4
 	tristate "Amlogic RTC"
 	depends on ARCH_MESON || COMPILE_TEST
 	select REGMAP_MMIO
-	default y
+	default ARCH_MESON
 	help
 	  If you say yes here you get support for the RTC block on the
 	  Amlogic A113L2(A4) and A113X2(A5) SoCs.
 
 	  This driver can also be built as a module. If so, the module
 	  will be called "rtc-amlogic-a4".
 
+config RTC_DRV_S32G
+	tristate "RTC driver for S32G2/S32G3 SoCs"
+	depends on ARCH_S32 || COMPILE_TEST
+	depends on COMMON_CLK
+	help
+	  Say yes to enable RTC driver for platforms based on the
+	  S32G2/S32G3 SoC family.
+
+	  This RTC module can be used as a wakeup source.
+	  Please note that it is not battery-powered.
+
 endif # RTC_CLASS

drivers/rtc/Makefile

@@ -44,6 +44,7 @@ obj-$(CONFIG_RTC_DRV_CADENCE)	+= rtc-cadence.o
 obj-$(CONFIG_RTC_DRV_CMOS)	+= rtc-cmos.o
 obj-$(CONFIG_RTC_DRV_CPCAP)	+= rtc-cpcap.o
 obj-$(CONFIG_RTC_DRV_CROS_EC)	+= rtc-cros-ec.o
+obj-$(CONFIG_RTC_DRV_CV1800)	+= rtc-cv1800.o
 obj-$(CONFIG_RTC_DRV_DA9052)	+= rtc-da9052.o
 obj-$(CONFIG_RTC_DRV_DA9055)	+= rtc-da9055.o
 obj-$(CONFIG_RTC_DRV_DA9063)	+= rtc-da9063.o
@@ -160,6 +161,7 @@ obj-$(CONFIG_RTC_DRV_RX8111)	+= rtc-rx8111.o
 obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o
 obj-$(CONFIG_RTC_DRV_RZN1)	+= rtc-rzn1.o
 obj-$(CONFIG_RTC_DRV_RENESAS_RTCA3)	+= rtc-renesas-rtca3.o
+obj-$(CONFIG_RTC_DRV_S32G)	+= rtc-s32g.o
 obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o
 obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o
 obj-$(CONFIG_RTC_DRV_S5M)	+= rtc-s5m.o

drivers/rtc/class.c

@@ -326,7 +326,7 @@ static void rtc_device_get_offset(struct rtc_device *rtc)
 	 *
 	 * Otherwise the offset seconds should be 0.
 	 */
-	if (rtc->start_secs > rtc->range_max ||
+	if ((rtc->start_secs >= 0 && rtc->start_secs > rtc->range_max) ||
 	    rtc->start_secs + range_secs - 1 < rtc->range_min)
 		rtc->offset_secs = rtc->start_secs - rtc->range_min;
 	else if (rtc->start_secs > rtc->range_min)

drivers/rtc/interface.c

@@ -205,7 +205,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc,
 
 	mutex_unlock(&rtc->ops_lock);
 
-	trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
+	trace_rtc_read_alarm(err?0:rtc_tm_to_time64(&alarm->time), err);
 	return err;
 }
 

drivers/rtc/lib.c

@@ -46,24 +46,38 @@ EXPORT_SYMBOL(rtc_year_days);
  * rtc_time64_to_tm - converts time64_t to rtc_time.
  *
  * @time:	The number of seconds since 01-01-1970 00:00:00.
- *		(Must be positive.)
+ *		Works for values since at least 1900
  * @tm:		Pointer to the struct rtc_time.
  */
 void rtc_time64_to_tm(time64_t time, struct rtc_time *tm)
 {
-	unsigned int secs;
-	int days;
+	int days, secs;
 
 	u64 u64tmp;
 	u32 u32tmp, udays, century, day_of_century, year_of_century, year,
 		day_of_year, month, day;
 	bool is_Jan_or_Feb, is_leap_year;
 
-	/* time must be positive */
+	/*
+	 * Get days and seconds while preserving the sign to
+	 * handle negative time values (dates before 1970-01-01)
+	 */
 	days = div_s64_rem(time, 86400, &secs);
 
+	/*
+	 * We need 0 <= secs < 86400 which isn't given for negative
+	 * values of time. Fixup accordingly.
+	 */
+	if (secs < 0) {
+		days -= 1;
+		secs += 86400;
+	}
+
 	/* day of the week, 1970-01-01 was a Thursday */
 	tm->tm_wday = (days + 4) % 7;
+	/* Ensure tm_wday is always positive */
+	if (tm->tm_wday < 0)
+		tm->tm_wday += 7;
 
 	/*
 	 * The following algorithm is, basically, Proposition 6.3 of Neri
@@ -93,7 +107,7 @@ void rtc_time64_to_tm(time64_t time, struct rtc_time *tm)
 	 * thus, is slightly different from [1].
 	 */
 
-	udays		= ((u32) days) + 719468;
+	udays		= days + 719468;
 
 	u32tmp		= 4 * udays + 3;
 	century		= u32tmp / 146097;