[PATCH v12 0/3] riscv: rtc: sophgo: add rtc support for CV1800

[PATCH v12 0/3] riscv: rtc: sophgo: add rtc support for CV1800

[Alexander Sverdlin]

Real Time Clock (RTC) is an independently powered module within the chip,
which includes a 32KHz oscillator and a Power On Reset/POR submodule. It
can be used for time display and timed alarm generation.

This series aims to provide complete DT bindings, but the drivers are only
focusing on RTC implementation. Possible Power Management and remoteproc
can be implemented later (hence the RTC driver is using syscon, because
MMIO space is really interleaved among different functions).

Series is tested on Milk-V Duo Module 01 EVB (SG2000 SoC).

Changes since v11:
- dropped restart handling (will be implemented in PSCI)
- split RTC driver into MFD stub and a platform RTC driver
- dropped Reviewed-by: Krzysztof Kozlowski from bindings, they've got a
  rework
- changed bindings maintainer from Jingbao Qiu <qiujingbao.dlmu@gmail.com>
  to sophgo@lists.linux.dev
- added link to TRM into bindings description
- bindings: mentioned 8051 core in the description
- bindings are now MFD, not RTC
- bindings: added "syscon" compatible
- bindings: added "interrupt-names", "clock-names" (because of added
  PM/remoteproc)
- bindings: main compatible "sophgo,cv1800-rtc" -> "sophgo,cv1800b-rtc"
- new patch "mfd: sophgo: cv1800: rtcsys: New driver (handling RTC only)"
- added both MFD and RTC drivers into MAINTAINERS file (N: K: entries
  didn't apply)
- RTC: depends on cv1800-rtcsys MFD driver
- RTC: use syscon for regmap
- RTC: get named clock from parent MFD
Changes since v10:
- only start RTC on set_time;
Changes since v9:
- further simplified bitmask macros;
- unconditional RTC start (rtc_enable_sec_counter()), otherwise
didn't start on SG2000;
- dropped ANA_CALIB modification (has been forgotten in v8 with
the drop of SW calibration to switch to HW calibration);
- successfully tested on SG2000;

Changes since v10:
- only start RTC on set_time;
- add machine restart handler (as separate patch 3/3);

Changes since v9:
- picked up orphaned series;
- further simplified bitmask macros;
- unconditional RTC start (rtc_enable_sec_counter());
- dropped ANA_CALIB modification;
- successfully tested on SG2000;

v9: https://lore.kernel.org/linux-riscv/20240428060848.706573-1-qiujingbao.dlmu@gmail.com/

Changes since v8:
- delete unused macros
- using 0/1 instead of the DISABLE/ENABLE macro
- pass in the correct pointer when applying for IRQ
- convert the incoming pointer into an appropriate
  structure pointer in the irq handler

v8: https://lore.kernel.org/all/20240204044143.415915-1-qiujingbao.dlmu@gmail.com/

Changes since v7:
- pass checkpatch.pl --strict
- using u32 replace uint32
- using devm_kzalloc(*) replace
  devm_kzalloc(sizeof())
- sort header files alphabetically
- delete unnecessary header files
- fix wrap error
- drop dependent description
- using hardware automatic calibration replace
  software calibration. see documentation 197 page

v7: https://lore.kernel.org/all/20240122080500.2621-1-qiujingbao.dlmu@gmail.com/
documentation: https://github.com/milkv-duo/duo-files/blob/main/duo/datasheet/CV1800B-CV1801B-Preliminary-Datasheet-full-en.pdf

Changes since v6:
- completely delete POR dt node
- remove syscon tag
- use devm_regmap_init_mmio() replace
  syscon_node_to_regmap

v6: https://lore.kernel.org/all/20240115160600.5444-1-qiujingbao.dlmu@gmail.com/

Changes since v5:
- remove unnecessary lock
- fix cv1800_rtc_alarm_irq_enable()
- remove duplicate checks
- using alrm->enabled instead of unconditionally
  enabling
- remove disable alarms on probe
- using rtc_update_irq() replace mess of alarm
- remove leak clk
- useing devm_rtc_allocate_device() and
  devm_rtc_register_device() instead old way
- add judgment for rtc_enable_sec_counter()
- add POR nodes in DTS. This POR device shares
  the register region with the RTC device

v5: https://lore.kernel.org/all/20240108072253.30183-1-qiujingbao.dlmu@gmail.com/

Changes since v4:
- remove POR dt-bindings because it empty
- remove MFD dt-bindings because SoC does
  not have MFDs
- add syscon attribute to share registers
  with POR

v4: https://lore.kernel.org/all/20231229090643.116575-1-qiujingbao.dlmu@gmail.com/

Changes since v3:
- temporarily not submitting RTC driver code
  waiting for communication with IC designer
- add MFD dt-bindings
- add POR dt-bindings

v3: https://lore.kernel.org/all/20231226100431.331616-1-qiujingbao.dlmu@gmail.com/

Changes since v2:
- add mfd support for CV1800
- add rtc to mfd
- using regmap replace iomap
- merge register address in dts

v2: https://lore.kernel.org/lkml/20231217110952.78784-1-qiujingbao.dlmu@gmail.com/

Changes since v1
- fix duplicate names in subject
- using RTC replace RTC controller
- improve the properties of dt-bindings
- using `unevaluatedProperties` replace `additionalProperties`
- dt-bindings passed the test
- using `devm_platform_ioremap_resource()` replace
  `platform_get_resource()` and `devm_ioremap_resource()`
- fix random order of the code
- fix wrong wrapping of the `devm_request_irq()` and map the flag with dts
- using devm_clk_get_enabled replace `devm_clk_get()` and
  `clk_prepare_enable()`
- fix return style
- add rtc clock calibration function
- use spinlock when write register on read/set time

v1: https://lore.kernel.org/lkml/20231121094642.2973795-1-qiujingbao.dlmu@gmail.com/

Alexander Sverdlin (1):
  mfd: sophgo: cv1800: rtcsys: New driver (handling RTC only)

Jingbao Qiu (2):
  dt-bindings: mfd: sophgo: add RTC support for Sophgo CV1800 series SoC
  rtc: sophgo: add rtc support for Sophgo CV1800 SoC

 .../bindings/mfd/sophgo,cv1800b-rtc.yaml      |  86 +++++++
 MAINTAINERS                                   |   2 +
 drivers/mfd/Kconfig                           |  14 ++
 drivers/mfd/Makefile                          |   1 +
 drivers/mfd/cv1800-rtcsys.c                   |  66 ++++++
 drivers/rtc/Kconfig                           |  12 +
 drivers/rtc/Makefile                          |   1 +
 drivers/rtc/rtc-cv1800.c                      | 218 ++++++++++++++++++
 8 files changed, 400 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml
 create mode 100644 drivers/mfd/cv1800-rtcsys.c
 create mode 100644 drivers/rtc/rtc-cv1800.c

-- 
2.48.1

[PATCH v12 1/3] dt-bindings: mfd: sophgo: add RTC support for Sophgo CV1800 series SoC

[Alexander Sverdlin]

From: Jingbao Qiu <qiujingbao.dlmu@gmail.com>

Add RTC devicetree binding for Sophgo CV1800 series SoC. The device is
called RTC, but contains control registers of other HW blocks in its
address space, most notably of Power-on-Reset (PoR) module, DW8051 IP
(MCU core), accompanying SRAM, hence putting it in MFD subsystem.

Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
---
Changelog:
v12:
- maintainer Jingbao Qiu <qiujingbao.dlmu@gmail.com> -> sophgo@lists.linux.dev
- dropped Reviewed-by: Krzysztof Kozlowski
- link to TRM
- mentioned 8051 core in the description
- binding is now MFD, not RTC
- added "syscon" compatible
- added "interrupt-names", "clock-names" (because of added PM/remoteproc)
- main compatible "sophgo,cv1800-rtc" -> "sophgo,cv1800b-rtc"

 .../bindings/mfd/sophgo,cv1800b-rtc.yaml      | 86 +++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml

diff --git a/Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml b/Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml
new file mode 100644
index 000000000000..b80d68502c48
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/sophgo,cv1800b-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Real Time Clock of the Sophgo CV1800 SoC
+
+description:
+  The RTC (Real Time Clock) is an independently powered module in the chip. It
+  contains a 32KHz oscillator and a Power-On-Reset (POR) sub-module, which can
+  be used for time display and scheduled alarm produce. In addition, the
+  hardware state machine provides triggering and timing control for chip
+  power-on, power-off and reset.
+
+  Furthermore, the 8051 subsystem is located within RTCSYS and is independently
+  powered. System software can use the 8051 to manage wake conditions and wake
+  the system while the system is asleep, and communicate with external devices
+  through peripheral controllers.
+
+  Technical Reference Manual available at
+    https://github.com/sophgo/sophgo-doc/tree/main/SG200X/TRM
+
+maintainers:
+  - sophgo@lists.linux.dev
+
+allOf:
+  - $ref: /schemas/rtc/rtc.yaml#
+
+properties:
+  compatible:
+    items:
+      - const: sophgo,cv1800b-rtc
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    items:
+      - description: RTC Alarm
+      - description: RTC Longpress
+      - description: VBAT DET
+
+  interrupt-names:
+    items:
+      - const: alarm
+      - const: longpress
+      - const: vbat
+
+  clocks:
+    items:
+      - description: RTC clock source
+      - description: DW8051 MCU clock source
+
+  clock-names:
+    items:
+      - const: rtc
+      - const: mcu
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-names
+  - clocks
+  - clock-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/sophgo,cv1800.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    rtc@5025000 {
+        compatible = "sophgo,cv1800b-rtc", "syscon";
+        reg = <0x5025000 0x2000>;
+        interrupts = <17 IRQ_TYPE_LEVEL_HIGH>,
+                     <18 IRQ_TYPE_LEVEL_HIGH>,
+                     <19 IRQ_TYPE_LEVEL_HIGH>;
+        interrupt-names = "alarm", "longpress", "vbat";
+        clocks = <&clk CLK_RTC_25M>,
+                 <&clk CLK_SRC_RTC_SYS_0>;
+        clock-names = "rtc", "mcu";
+    };
-- 
2.48.1

[PATCH v12 2/3] mfd: sophgo: cv1800: rtcsys: New driver (handling RTC only)

[Alexander Sverdlin]

Add driver for Sophgo CV1800 series SoC RTC MFD. The RTC module comprises
a 32kHz oscillator, Power-on-Reset (PoR) sub-module, HW state machine to
control chip power-on, power-off and reset. Furthermore, the 8051 subsystem
is located within RTCSYS including associated SRAM block.

This patch only populates RTC sub-device.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
---
Changelog:
v12:
- new patch

 MAINTAINERS                 |  1 +
 drivers/mfd/Kconfig         | 14 ++++++++
 drivers/mfd/Makefile        |  1 +
 drivers/mfd/cv1800-rtcsys.c | 66 +++++++++++++++++++++++++++++++++++++
 4 files changed, 82 insertions(+)
 create mode 100644 drivers/mfd/cv1800-rtcsys.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 92fc0eca7061..446156998380 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22185,6 +22185,7 @@ M:	Chen Wang <unicorn_wang@outlook.com>
 M:	Inochi Amaoto <inochiama@outlook.com>
 T:	git https://github.com/sophgo/linux.git
 S:	Maintained
+F:	drivers/mfd/cv1800-rtcsys.c
 N:	sophgo
 K:	sophgo
 
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 6b0682af6e32..842cc4d95c4b 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -285,6 +285,20 @@ config MFD_CS42L43_SDW
 	  Select this to support the Cirrus Logic CS42L43 PC CODEC with
 	  headphone and class D speaker drivers over SoundWire.
 
+config MFD_CV1800_RTCSYS
+	tristate "Sophgo CV1800 RTC MFD"
+	depends on ARCH_SOPHGO || COMPILE_TEST
+	select MFD_CORE
+	help
+	  If you say yes here you get support the RTC MFD driver for Sophgo
+	  CV1800 series SoC. The RTC module comprises a 32kHz oscillator,
+	  Power-on-Reset (PoR) sub-module, HW state machine to control chip
+	  power-on, power-off and reset. Furthermore, the 8051 subsystem is
+	  located within RTCSYS including associated SRAM block.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called cv1800-rtcsys.
+
 config MFD_MADERA
 	tristate "Cirrus Logic Madera codecs"
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 9220eaf7cf12..3cf03ffeedbb 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_MFD_CROS_EC_DEV)	+= cros_ec_dev.o
 obj-$(CONFIG_MFD_CS42L43)	+= cs42l43.o
 obj-$(CONFIG_MFD_CS42L43_I2C)	+= cs42l43-i2c.o
 obj-$(CONFIG_MFD_CS42L43_SDW)	+= cs42l43-sdw.o
+obj-$(CONFIG_MFD_CV1800_RTCSYS)	+= cv1800-rtcsys.o
 obj-$(CONFIG_MFD_ENE_KB3930)	+= ene-kb3930.o
 obj-$(CONFIG_MFD_EXYNOS_LPASS)	+= exynos-lpass.o
 obj-$(CONFIG_MFD_GATEWORKS_GSC)	+= gateworks-gsc.o
diff --git a/drivers/mfd/cv1800-rtcsys.c b/drivers/mfd/cv1800-rtcsys.c
new file mode 100644
index 000000000000..72d11284f1de
--- /dev/null
+++ b/drivers/mfd/cv1800-rtcsys.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Sophgo CV1800 series SoC RTC MFD
+ *
+ * The RTC module comprises a 32kHz oscillator, Power-on-Reset (PoR) sub-module,
+ * HW state machine to control chip power-on, power-off and reset. Furthermore,
+ * the 8051 subsystem is located within RTCSYS including associated SRAM block.
+ *
+ * Copyright (C) 2025 Alexander Sverdlin <alexander.sverdlin@gmail.com>
+ *
+ */
+
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/property.h>
+
+static struct resource cv1800_rtcsys_irq_resources[] = {
+	DEFINE_RES_IRQ_NAMED(0, "alarm"),
+};
+
+static const struct mfd_cell cv1800_rtcsys_subdev[] = {
+	{
+		.name = "cv1800-rtc",
+		.num_resources = 1,
+		.resources = &cv1800_rtcsys_irq_resources[0],
+	},
+};
+
+static const struct mfd_cell cv1800_rtcsys_rtc_subdev =
+	MFD_CELL_NAME("cv1800-rtc");
+
+static int cv1800_rtcsys_probe(struct platform_device *pdev)
+{
+	int irq;
+
+	irq = platform_get_irq_byname(pdev, "alarm");
+	if (irq < 0)
+		return irq;
+	cv1800_rtcsys_irq_resources[0].start = irq;
+	cv1800_rtcsys_irq_resources[0].end = irq;
+
+	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
+				    cv1800_rtcsys_subdev,
+				    ARRAY_SIZE(cv1800_rtcsys_subdev),
+				    NULL, 0, NULL);
+}
+
+static const struct of_device_id cv1800_rtcsys_of_match[] = {
+	{ .compatible = "sophgo,cv1800b-rtc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, cv1800_rtcsys_of_match);
+
+static struct platform_driver cv1800_rtcsys_mfd = {
+	.probe	= cv1800_rtcsys_probe,
+	.driver	= {
+		.name		= "cv1800_rtcsys",
+		.of_match_table	= cv1800_rtcsys_of_match,
+	},
+};
+module_platform_driver(cv1800_rtcsys_mfd);
+
+MODULE_AUTHOR("Alexander Sverdlin <alexander.sverdlin@gmail.com>");
+MODULE_DESCRIPTION("Sophgo CV1800 series SoC RTC MFD driver");
+MODULE_LICENSE("GPL");
-- 
2.48.1

[PATCH v12 3/3] rtc: sophgo: add rtc support for Sophgo CV1800 SoC

[Alexander Sverdlin]

From: Jingbao Qiu <qiujingbao.dlmu@gmail.com>

Implement the RTC driver for CV1800, which able to provide time alarm.

Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
---
v12:
- added MAINTAINERS entry
- depends on cv1800-rtcsys MFD driver
- use syscon for regmap
- get named clock from parent MFD
- corresponding platform device is expected to be instantiated by MFD stub
Changes since v10:
- only start RTC on set_time;
Changes since v9:
- further simplified bitmask macros;
- unconditional RTC start (rtc_enable_sec_counter()), otherwise
didn't start on SG2000;
- dropped ANA_CALIB modification (has been forgotten in v8 with
the drop of SW calibration to switch to HW calibration);
- successfully tested on SG2000;

 MAINTAINERS              |   1 +
 drivers/rtc/Kconfig      |  12 +++
 drivers/rtc/Makefile     |   1 +
 drivers/rtc/rtc-cv1800.c | 218 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 232 insertions(+)
 create mode 100644 drivers/rtc/rtc-cv1800.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 446156998380..d4e0569da602 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22186,6 +22186,7 @@ M:	Inochi Amaoto <inochiama@outlook.com>
 T:	git https://github.com/sophgo/linux.git
 S:	Maintained
 F:	drivers/mfd/cv1800-rtcsys.c
+F:	drivers/rtc/rtc-cv1800.c
 N:	sophgo
 K:	sophgo
 
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 0bbbf778ecfa..9da247ec4084 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1395,6 +1395,18 @@ 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 MFD_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
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 489b4ab07068..621b30a33dda 100644
--- a/drivers/rtc/Makefile
+++ b/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
diff --git a/drivers/rtc/rtc-cv1800.c b/drivers/rtc/rtc-cv1800.c
new file mode 100644
index 000000000000..18bc542bbdb8
--- /dev/null
+++ b/drivers/rtc/rtc-cv1800.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * rtc-cv1800.c: RTC driver for Sophgo cv1800 RTC
+ *
+ * Author: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+
+#define SEC_PULSE_GEN          0x1004
+#define ALARM_TIME             0x1008
+#define ALARM_ENABLE           0x100C
+#define SET_SEC_CNTR_VAL       0x1010
+#define SET_SEC_CNTR_TRIG      0x1014
+#define SEC_CNTR_VAL           0x1018
+
+/*
+ * When in VDDBKUP domain, this MACRO register
+ * does not power down
+ */
+#define MACRO_RO_T             0x14A8
+#define MACRO_RG_SET_T         0x1498
+
+#define ALARM_ENABLE_MASK      BIT(0)
+#define SEL_SEC_PULSE          BIT(31)
+
+struct cv1800_rtc_priv {
+	struct rtc_device *rtc_dev;
+	struct regmap *rtc_map;
+	struct clk *clk;
+	int irq;
+};
+
+static bool cv1800_rtc_enabled(struct device *dev)
+{
+	struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+	u32 reg;
+
+	regmap_read(info->rtc_map, SEC_PULSE_GEN, &reg);
+
+	return (reg & SEL_SEC_PULSE) == 0;
+}
+
+static void cv1800_rtc_enable(struct device *dev)
+{
+	struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+
+	/* Sec pulse generated internally */
+	regmap_update_bits(info->rtc_map, SEC_PULSE_GEN, SEL_SEC_PULSE, 0);
+}
+
+static int cv1800_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+
+	regmap_write(info->rtc_map, ALARM_ENABLE, enabled);
+
+	return 0;
+}
+
+static int cv1800_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+	unsigned long alarm_time;
+
+	alarm_time = rtc_tm_to_time64(&alrm->time);
+
+	cv1800_rtc_alarm_irq_enable(dev, 0);
+
+	regmap_write(info->rtc_map, ALARM_TIME, alarm_time);
+
+	cv1800_rtc_alarm_irq_enable(dev, alrm->enabled);
+
+	return 0;
+}
+
+static int cv1800_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+	u32 enabled;
+	u32 time;
+
+	if (!cv1800_rtc_enabled(dev)) {
+		alarm->enabled = 0;
+		return 0;
+	}
+
+	regmap_read(info->rtc_map, ALARM_ENABLE, &enabled);
+
+	alarm->enabled = enabled & ALARM_ENABLE_MASK;
+
+	regmap_read(info->rtc_map, ALARM_TIME, &time);
+
+	rtc_time64_to_tm(time, &alarm->time);
+
+	return 0;
+}
+
+static int cv1800_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+	u32 sec;
+
+	if (!cv1800_rtc_enabled(dev))
+		return -EINVAL;
+
+	regmap_read(info->rtc_map, SEC_CNTR_VAL, &sec);
+
+	rtc_time64_to_tm(sec, tm);
+
+	return 0;
+}
+
+static int cv1800_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct cv1800_rtc_priv *info = dev_get_drvdata(dev);
+	unsigned long sec;
+
+	sec = rtc_tm_to_time64(tm);
+
+	regmap_write(info->rtc_map, SET_SEC_CNTR_VAL, sec);
+	regmap_write(info->rtc_map, SET_SEC_CNTR_TRIG, 1);
+
+	regmap_write(info->rtc_map, MACRO_RG_SET_T, sec);
+
+	cv1800_rtc_enable(dev);
+
+	return 0;
+}
+
+static irqreturn_t cv1800_rtc_irq_handler(int irq, void *dev_id)
+{
+	struct cv1800_rtc_priv *info = dev_id;
+
+	rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+	regmap_write(info->rtc_map, ALARM_ENABLE, 0);
+
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops cv1800_rtc_ops = {
+	.read_time = cv1800_rtc_read_time,
+	.set_time = cv1800_rtc_set_time,
+	.read_alarm = cv1800_rtc_read_alarm,
+	.set_alarm = cv1800_rtc_set_alarm,
+	.alarm_irq_enable = cv1800_rtc_alarm_irq_enable,
+};
+
+static int cv1800_rtc_probe(struct platform_device *pdev)
+{
+	struct cv1800_rtc_priv *rtc;
+	int ret;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	rtc->rtc_map = device_node_to_regmap(pdev->dev.parent->of_node);
+	if (IS_ERR(rtc->rtc_map))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->rtc_map),
+				     "cannot get parent regmap\n");
+
+	rtc->irq = platform_get_irq(pdev, 0);
+	if (rtc->irq < 0)
+		return rtc->irq;
+
+	rtc->clk = devm_clk_get_enabled(pdev->dev.parent, "rtc");
+	if (IS_ERR(rtc->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->clk),
+				     "rtc clk not found\n");
+
+	platform_set_drvdata(pdev, rtc);
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc->rtc_dev))
+		return PTR_ERR(rtc->rtc_dev);
+
+	rtc->rtc_dev->ops = &cv1800_rtc_ops;
+	rtc->rtc_dev->range_max = U32_MAX;
+
+	ret = devm_request_irq(&pdev->dev, rtc->irq, cv1800_rtc_irq_handler,
+			       IRQF_TRIGGER_HIGH, "rtc alarm", rtc);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "cannot register interrupt handler\n");
+
+	return devm_rtc_register_device(rtc->rtc_dev);
+}
+
+static const struct platform_device_id cv1800_rtc_id[] = {
+	{ .name = "cv1800-rtc" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(platform, cv1800_rtc_id);
+
+static struct platform_driver cv1800_rtc_driver = {
+	.driver = {
+		.name = "sophgo-cv1800-rtc",
+	},
+	.probe = cv1800_rtc_probe,
+	.id_table = cv1800_rtc_id,
+};
+
+module_platform_driver(cv1800_rtc_driver);
+MODULE_AUTHOR("Jingbao Qiu");
+MODULE_DESCRIPTION("Sophgo cv1800 RTC Driver");
+MODULE_LICENSE("GPL");
-- 
2.48.1

Re: [PATCH v12 1/3] dt-bindings: mfd: sophgo: add RTC support for Sophgo CV1800 series SoC

[Krzysztof Kozlowski]

On Sun, Mar 02, 2025 at 08:51:54PM +0100, Alexander Sverdlin wrote:
> From: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> 
> Add RTC devicetree binding for Sophgo CV1800 series SoC. The device is
> called RTC, but contains control registers of other HW blocks in its
> address space, most notably of Power-on-Reset (PoR) module, DW8051 IP
> (MCU core), accompanying SRAM, hence putting it in MFD subsystem.

Assuming this is integrated block in the CV1800 SoC, then this should go
to soc/ and probably called system controller or similarly.

How is it called in the datasheet?


> 
> Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
> ---
> Changelog:
> v12:
> - maintainer Jingbao Qiu <qiujingbao.dlmu@gmail.com> -> sophgo@lists.linux.dev
> - dropped Reviewed-by: Krzysztof Kozlowski
> - link to TRM
> - mentioned 8051 core in the description
> - binding is now MFD, not RTC
> - added "syscon" compatible
> - added "interrupt-names", "clock-names" (because of added PM/remoteproc)
> - main compatible "sophgo,cv1800-rtc" -> "sophgo,cv1800b-rtc"
> 
>  .../bindings/mfd/sophgo,cv1800b-rtc.yaml      | 86 +++++++++++++++++++
>  1 file changed, 86 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml b/Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml
> new file mode 100644
> index 000000000000..b80d68502c48
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/sophgo,cv1800b-rtc.yaml
> @@ -0,0 +1,86 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mfd/sophgo,cv1800b-rtc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Real Time Clock of the Sophgo CV1800 SoC
> +
> +description:
> +  The RTC (Real Time Clock) is an independently powered module in the chip. It
> +  contains a 32KHz oscillator and a Power-On-Reset (POR) sub-module, which can
> +  be used for time display and scheduled alarm produce. In addition, the
> +  hardware state machine provides triggering and timing control for chip
> +  power-on, power-off and reset.
> +
> +  Furthermore, the 8051 subsystem is located within RTCSYS and is independently
> +  powered. System software can use the 8051 to manage wake conditions and wake
> +  the system while the system is asleep, and communicate with external devices
> +  through peripheral controllers.
> +
> +  Technical Reference Manual available at
> +    https://github.com/sophgo/sophgo-doc/tree/main/SG200X/TRM
> +
> +maintainers:
> +  - sophgo@lists.linux.dev
> +
> +allOf:
> +  - $ref: /schemas/rtc/rtc.yaml#
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: sophgo,cv1800b-rtc
> +      - const: syscon

Binding is fine, but still open topics are: placement and compatible
name.

Best regards,
Krzysztof

Re: [PATCH v12 2/3] mfd: sophgo: cv1800: rtcsys: New driver (handling RTC only)

[kernel test robot]

Hi Alexander,

kernel test robot noticed the following build warnings:

[auto build test WARNING on lee-mfd/for-mfd-next]
[also build test WARNING on abelloni/rtc-next linus/master lee-mfd/for-mfd-fixes v6.14-rc5 next-20250305]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Alexander-Sverdlin/dt-bindings-mfd-sophgo-add-RTC-support-for-Sophgo-CV1800-series-SoC/20250303-035433
base:   https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git for-mfd-next
patch link:    https://lore.kernel.org/r/20250302195205.3183174-3-alexander.sverdlin%40gmail.com
patch subject: [PATCH v12 2/3] mfd: sophgo: cv1800: rtcsys: New driver (handling RTC only)
config: hexagon-allyesconfig (https://download.01.org/0day-ci/archive/20250306/202503060435.1c1akI1Q-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250306/202503060435.1c1akI1Q-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503060435.1c1akI1Q-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/mfd/cv1800-rtcsys.c:30:30: warning: unused variable 'cv1800_rtcsys_rtc_subdev' [-Wunused-const-variable]
      30 | static const struct mfd_cell cv1800_rtcsys_rtc_subdev =
         |                              ^~~~~~~~~~~~~~~~~~~~~~~~
   1 warning generated.


vim +/cv1800_rtcsys_rtc_subdev +30 drivers/mfd/cv1800-rtcsys.c

    29	
  > 30	static const struct mfd_cell cv1800_rtcsys_rtc_subdev =
    31		MFD_CELL_NAME("cv1800-rtc");
    32	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v12 2/3] mfd: sophgo: cv1800: rtcsys: New driver (handling RTC only)

[Lee Jones]

On Sun, 02 Mar 2025, Alexander Sverdlin wrote:

> Add driver for Sophgo CV1800 series SoC RTC MFD. The RTC module comprises
> a 32kHz oscillator, Power-on-Reset (PoR) sub-module, HW state machine to
> control chip power-on, power-off and reset. Furthermore, the 8051 subsystem
> is located within RTCSYS including associated SRAM block.
> 
> This patch only populates RTC sub-device.
> 
> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
> ---
> Changelog:
> v12:
> - new patch
> 
>  MAINTAINERS                 |  1 +
>  drivers/mfd/Kconfig         | 14 ++++++++
>  drivers/mfd/Makefile        |  1 +
>  drivers/mfd/cv1800-rtcsys.c | 66 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 82 insertions(+)
>  create mode 100644 drivers/mfd/cv1800-rtcsys.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 92fc0eca7061..446156998380 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -22185,6 +22185,7 @@ M:	Chen Wang <unicorn_wang@outlook.com>
>  M:	Inochi Amaoto <inochiama@outlook.com>
>  T:	git https://github.com/sophgo/linux.git
>  S:	Maintained
> +F:	drivers/mfd/cv1800-rtcsys.c
>  N:	sophgo
>  K:	sophgo
>  
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 6b0682af6e32..842cc4d95c4b 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -285,6 +285,20 @@ config MFD_CS42L43_SDW
>  	  Select this to support the Cirrus Logic CS42L43 PC CODEC with
>  	  headphone and class D speaker drivers over SoundWire.
>  
> +config MFD_CV1800_RTCSYS
> +	tristate "Sophgo CV1800 RTC MFD"
> +	depends on ARCH_SOPHGO || COMPILE_TEST
> +	select MFD_CORE
> +	help
> +	  If you say yes here you get support the RTC MFD driver for Sophgo
> +	  CV1800 series SoC. The RTC module comprises a 32kHz oscillator,
> +	  Power-on-Reset (PoR) sub-module, HW state machine to control chip
> +	  power-on, power-off and reset. Furthermore, the 8051 subsystem is
> +	  located within RTCSYS including associated SRAM block.
> +
> +	  This driver can also be built as a module. If so, the module will be
> +	  called cv1800-rtcsys.
> +
>  config MFD_MADERA
>  	tristate "Cirrus Logic Madera codecs"
>  	select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 9220eaf7cf12..3cf03ffeedbb 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -18,6 +18,7 @@ obj-$(CONFIG_MFD_CROS_EC_DEV)	+= cros_ec_dev.o
>  obj-$(CONFIG_MFD_CS42L43)	+= cs42l43.o
>  obj-$(CONFIG_MFD_CS42L43_I2C)	+= cs42l43-i2c.o
>  obj-$(CONFIG_MFD_CS42L43_SDW)	+= cs42l43-sdw.o
> +obj-$(CONFIG_MFD_CV1800_RTCSYS)	+= cv1800-rtcsys.o
>  obj-$(CONFIG_MFD_ENE_KB3930)	+= ene-kb3930.o
>  obj-$(CONFIG_MFD_EXYNOS_LPASS)	+= exynos-lpass.o
>  obj-$(CONFIG_MFD_GATEWORKS_GSC)	+= gateworks-gsc.o
> diff --git a/drivers/mfd/cv1800-rtcsys.c b/drivers/mfd/cv1800-rtcsys.c
> new file mode 100644
> index 000000000000..72d11284f1de
> --- /dev/null
> +++ b/drivers/mfd/cv1800-rtcsys.c
> @@ -0,0 +1,66 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for Sophgo CV1800 series SoC RTC MFD
> + *
> + * The RTC module comprises a 32kHz oscillator, Power-on-Reset (PoR) sub-module,
> + * HW state machine to control chip power-on, power-off and reset. Furthermore,
> + * the 8051 subsystem is located within RTCSYS including associated SRAM block.
> + *
> + * Copyright (C) 2025 Alexander Sverdlin <alexander.sverdlin@gmail.com>
> + *
> + */
> +
> +#include <linux/mfd/core.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/property.h>
> +
> +static struct resource cv1800_rtcsys_irq_resources[] = {
> +	DEFINE_RES_IRQ_NAMED(0, "alarm"),
> +};
> +
> +static const struct mfd_cell cv1800_rtcsys_subdev[] = {
> +	{
> +		.name = "cv1800-rtc",
> +		.num_resources = 1,
> +		.resources = &cv1800_rtcsys_irq_resources[0],
> +	},
> +};
> +
> +static const struct mfd_cell cv1800_rtcsys_rtc_subdev =
> +	MFD_CELL_NAME("cv1800-rtc");

How is this different from the one above?

Adding a single device does not constitute an MFD.

> +static int cv1800_rtcsys_probe(struct platform_device *pdev)
> +{
> +	int irq;
> +
> +	irq = platform_get_irq_byname(pdev, "alarm");
> +	if (irq < 0)
> +		return irq;
> +	cv1800_rtcsys_irq_resources[0].start = irq;
> +	cv1800_rtcsys_irq_resources[0].end = irq;
> +
> +	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
> +				    cv1800_rtcsys_subdev,
> +				    ARRAY_SIZE(cv1800_rtcsys_subdev),
> +				    NULL, 0, NULL);
> +}
> +
> +static const struct of_device_id cv1800_rtcsys_of_match[] = {
> +	{ .compatible = "sophgo,cv1800b-rtc" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, cv1800_rtcsys_of_match);
> +
> +static struct platform_driver cv1800_rtcsys_mfd = {
> +	.probe	= cv1800_rtcsys_probe,
> +	.driver	= {
> +		.name		= "cv1800_rtcsys",
> +		.of_match_table	= cv1800_rtcsys_of_match,
> +	},
> +};
> +module_platform_driver(cv1800_rtcsys_mfd);
> +
> +MODULE_AUTHOR("Alexander Sverdlin <alexander.sverdlin@gmail.com>");
> +MODULE_DESCRIPTION("Sophgo CV1800 series SoC RTC MFD driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.48.1
> 

-- 
Lee Jones [李琼斯]

Re: [PATCH v12 2/3] mfd: sophgo: cv1800: rtcsys: New driver (handling RTC only)

[kernel test robot]

Hi Alexander,

kernel test robot noticed the following build warnings:

[auto build test WARNING on lee-mfd/for-mfd-next]
[also build test WARNING on abelloni/rtc-next linus/master lee-mfd/for-mfd-fixes v6.14-rc5 next-20250305]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Alexander-Sverdlin/dt-bindings-mfd-sophgo-add-RTC-support-for-Sophgo-CV1800-series-SoC/20250303-035433
base:   https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git for-mfd-next
patch link:    https://lore.kernel.org/r/20250302195205.3183174-3-alexander.sverdlin%40gmail.com
patch subject: [PATCH v12 2/3] mfd: sophgo: cv1800: rtcsys: New driver (handling RTC only)
config: sh-allyesconfig (https://download.01.org/0day-ci/archive/20250306/202503061309.yjpOnrMo-lkp@intel.com/config)
compiler: sh4-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250306/202503061309.yjpOnrMo-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503061309.yjpOnrMo-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/mfd/cv1800-rtcsys.c:30:30: warning: 'cv1800_rtcsys_rtc_subdev' defined but not used [-Wunused-const-variable=]
      30 | static const struct mfd_cell cv1800_rtcsys_rtc_subdev =
         |                              ^~~~~~~~~~~~~~~~~~~~~~~~


vim +/cv1800_rtcsys_rtc_subdev +30 drivers/mfd/cv1800-rtcsys.c

    29	
  > 30	static const struct mfd_cell cv1800_rtcsys_rtc_subdev =
    31		MFD_CELL_NAME("cv1800-rtc");
    32	

-- 
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https://github.com/intel/lkp-tests/wiki