Merge tag 'rtc-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "Support for a new RTC in an existing driver and all the drivers
  exposing clocks using the common clock framework have been converted
  to determine_rate(). Summary:

  Subsystem:
   - Convert drivers exposing a clock from round_rate() to determine_rate()

  Drivers:
   - ds1307: oscillator stop flag handling for ds1341
   - pcf85063: add support for RV8063"

* tag 'rtc-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (34 commits)
  rtc: ds1685: Update Joshua Kinard's email address.
  rtc: rv3032: convert from round_rate() to determine_rate()
  rtc: rv3028: convert from round_rate() to determine_rate()
  rtc: pcf8563: convert from round_rate() to determine_rate()
  rtc: pcf85063: convert from round_rate() to determine_rate()
  rtc: nct3018y: convert from round_rate() to determine_rate()
  rtc: max31335: convert from round_rate() to determine_rate()
  rtc: m41t80: convert from round_rate() to determine_rate()
  rtc: hym8563: convert from round_rate() to determine_rate()
  rtc: ds1307: convert from round_rate() to determine_rate()
  rtc: rv3028: fix incorrect maximum clock rate handling
  rtc: pcf8563: fix incorrect maximum clock rate handling
  rtc: pcf85063: fix incorrect maximum clock rate handling
  rtc: nct3018y: fix incorrect maximum clock rate handling
  rtc: hym8563: fix incorrect maximum clock rate handling
  rtc: ds1307: fix incorrect maximum clock rate handling
  rtc: pcf85063: scope pcf85063_config structures
  rtc: Optimize calculations in rtc_time64_to_tm()
  dt-bindings: rtc: amlogic,a4-rtc: Add compatible string for C3
  rtc: ds1307: handle oscillator stop flag (OSF) for ds1341
  ...

Author: torvalds

Documentation/devicetree/bindings/rtc/amlogic,a4-rtc.yaml

@@ -16,9 +16,14 @@ allOf:
 
 properties:
   compatible:
-    enum:
-      - amlogic,a4-rtc
-      - amlogic,a5-rtc
+    oneOf:
+      - enum:
+          - amlogic,a4-rtc
+          - amlogic,a5-rtc
+      - items:
+          - enum:
+              - amlogic,c3-rtc
+          - const: amlogic,a5-rtc
 
   reg:
     maxItems: 1

Documentation/devicetree/bindings/rtc/nxp,lpc1788-rtc.yaml

@@ -18,7 +18,12 @@ allOf:
 
 properties:
   compatible:
-    const: nxp,lpc1788-rtc
+    oneOf:
+      - items:
+          - enum:
+              - nxp,lpc1850-rtc
+          - const: nxp,lpc1788-rtc
+      - const: nxp,lpc1788-rtc
 
   reg:
     maxItems: 1

Documentation/devicetree/bindings/rtc/nxp,lpc3220-rtc.yaml

@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/nxp,lpc3220-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP LPC32xx SoC Real-time Clock
+
+maintainers:
+  - Frank Li <[email protected]>
+
+properties:
+  compatible:
+    enum:
+      - nxp,lpc3220-rtc
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  start-year: true
+
+required:
+  - compatible
+  - reg
+
+allOf:
+  - $ref: rtc.yaml#
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/clock/lpc32xx-clock.h>
+
+    rtc@40024000 {
+        compatible = "nxp,lpc3220-rtc";
+        reg = <0x40024000 0x1000>;
+        interrupt-parent = <&sic1>;
+        interrupts = <20 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clk LPC32XX_CLK_RTC>;
+    };
+

Documentation/devicetree/bindings/rtc/nxp,pcf85063.yaml

@@ -12,6 +12,7 @@ maintainers:
 properties:
   compatible:
     enum:
+      - microcrystal,rv8063
       - microcrystal,rv8263
       - nxp,pcf85063
       - nxp,pcf85063a
@@ -44,13 +45,19 @@ properties:
 
   wakeup-source: true
 
+  spi-cs-high: true
+
+  spi-3wire: true
+
 allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
   - $ref: rtc.yaml#
   - if:
       properties:
         compatible:
           contains:
             enum:
+              - microcrystal,rv8063
               - microcrystal,rv8263
     then:
       properties:
@@ -65,12 +72,23 @@ allOf:
       properties:
         quartz-load-femtofarads:
           const: 7000
+  - if:
+      properties:
+        compatible:
+          not:
+            contains:
+              enum:
+                - microcrystal,rv8063
+    then:
+      properties:
+        spi-cs-high: false
+        spi-3wire: false
 
 required:
   - compatible
   - reg
 
-additionalProperties: false
+unevaluatedProperties: false
 
 examples:
   - |
@@ -90,3 +108,16 @@ examples:
           };
         };
       };
+
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        rtc@0 {
+            compatible = "microcrystal,rv8063";
+            reg = <0>;
+            spi-cs-high;
+            spi-3wire;
+        };
+    };

Documentation/devicetree/bindings/soc/sophgo/sophgo,cv1800b-rtc.yaml renamed to Documentation/devicetree/bindings/rtc/sophgo,cv1800b-rtc.yaml

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 %YAML 1.2
 ---
-$id: http://devicetree.org/schemas/sophgo/sophgo,cv1800b-rtc.yaml#
+$id: http://devicetree.org/schemas/rtc/sophgo,cv1800b-rtc.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
 title: Real Time Clock of the Sophgo CV1800 SoC

Documentation/devicetree/bindings/rtc/trivial-rtc.yaml

@@ -63,8 +63,6 @@ properties:
       - microcrystal,rv3029
       # Real Time Clock
       - microcrystal,rv8523
-      # NXP LPC32xx SoC Real-time Clock
-      - nxp,lpc3220-rtc
       # I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
       - ricoh,r2025sd
       # I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC

MAINTAINERS

@@ -6713,7 +6713,7 @@ S:	Supported
 F:	drivers/input/keyboard/dlink-dir685-touchkeys.c
 
 DALLAS/MAXIM DS1685-FAMILY REAL TIME CLOCK
-M:	Joshua Kinard <[email protected]>
+M:	Joshua Kinard <[email protected]>
 S:	Maintained
 F:	drivers/rtc/rtc-ds1685.c
 F:	include/linux/rtc/ds1685.h

drivers/rtc/Kconfig

@@ -483,15 +483,6 @@ config RTC_DRV_PCF8523
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-pcf8523.
 
-config RTC_DRV_PCF85063
-	tristate "NXP PCF85063"
-	select REGMAP_I2C
-	help
-	  If you say yes here you get support for the PCF85063 RTC chip
-
-	  This driver can also be built as a module. If so, the module
-	  will be called rtc-pcf85063.
-
 config RTC_DRV_PCF85363
 	tristate "NXP PCF85363"
 	select REGMAP_I2C
@@ -971,6 +962,18 @@ config RTC_DRV_PCF2127
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-pcf2127.
 
+config RTC_DRV_PCF85063
+	tristate "NXP PCF85063"
+	depends on RTC_I2C_AND_SPI
+	select REGMAP_I2C if I2C
+	select REGMAP_SPI if SPI_MASTER
+	help
+	  If you say yes here you get support for the PCF85063 and RV8063
+	  RTC chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-pcf85063.
+
 config RTC_DRV_RV3029C2
 	tristate "Micro Crystal RV3029/3049"
 	depends on RTC_I2C_AND_SPI

drivers/rtc/Makefile

@@ -15,7 +15,7 @@ rtc-core-$(CONFIG_RTC_INTF_DEV)		+= dev.o
 rtc-core-$(CONFIG_RTC_INTF_PROC)	+= proc.o
 rtc-core-$(CONFIG_RTC_INTF_SYSFS)	+= sysfs.o
 
-obj-$(CONFIG_RTC_LIB_KUNIT_TEST)	+= lib_test.o
+obj-$(CONFIG_RTC_LIB_KUNIT_TEST)	+= test_rtc_lib.o
 
 # Keep the list ordered.
 

drivers/rtc/lib.c

@@ -51,36 +51,34 @@ EXPORT_SYMBOL(rtc_year_days);
  */
 void rtc_time64_to_tm(time64_t time, struct rtc_time *tm)
 {
-	int days, secs;
+	int 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;
 
 	/*
-	 * Get days and seconds while preserving the sign to
-	 * handle negative time values (dates before 1970-01-01)
+	 * The time represented by `time` is given in seconds since 1970-01-01
+	 * (UTC). As the division done below might misbehave for negative
+	 * values, we convert it to seconds since 0000-03-01 and then assume it
+	 * will be non-negative.
+	 * Below we do 4 * udays + 3 which should fit into a 32 bit unsigned
+	 * variable. So the latest date this algorithm works for is 1073741823
+	 * days after 0000-03-01 which is in the year 2939805.
 	 */
-	days = div_s64_rem(time, 86400, &secs);
+	time += (u64)719468 * 86400;
+
+	udays = div_s64_rem(time, 86400, &secs);
 
 	/*
-	 * We need 0 <= secs < 86400 which isn't given for negative
-	 * values of time. Fixup accordingly.
+	 * day of the week, 0000-03-01 was a Wednesday (in the proleptic
+	 * Gregorian calendar)
 	 */
-	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;
+	tm->tm_wday = (udays + 3) % 7;
 
 	/*
-	 * The following algorithm is, basically, Proposition 6.3 of Neri
+	 * The following algorithm is, basically, Figure 12 of Neri
 	 * and Schneider [1]. In a few words: it works on the computational
 	 * (fictitious) calendar where the year starts in March, month = 2
 	 * (*), and finishes in February, month = 13. This calendar is
@@ -100,15 +98,15 @@ void rtc_time64_to_tm(time64_t time, struct rtc_time *tm)
 	 * (using just arithmetics) it's easy to convert it to the
 	 * corresponding date in the Gregorian calendar.
 	 *
-	 * [1] "Euclidean Affine Functions and Applications to Calendar
-	 * Algorithms". https://arxiv.org/abs/2102.06959
+	 * [1] Neri C, Schneider L. Euclidean affine functions and their
+	 *     application to calendar algorithms. Softw Pract Exper.
+	 *     2023;53(4):937-970. doi: 10.1002/spe.3172
+	 *     https://doi.org/10.1002/spe.3172
 	 *
 	 * (*) The numbering of months follows rtc_time more closely and
 	 * thus, is slightly different from [1].
 	 */
 
-	udays		= days + 719468;
-
 	u32tmp		= 4 * udays + 3;
 	century		= u32tmp / 146097;
 	day_of_century	= u32tmp % 146097 / 4;