soc: sophgo: cv1800: rtcsys: New driver (handling RTC only)

Add driver for Sophgo CV1800 series SoC RTC subsystem. 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>
Reviewed-by: Inochi Amaoto <inochiama@gmail.com>
Link: https://lore.kernel.org/r/20250315224921.3627852-3-alexander.sverdlin@gmail.com
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Signed-off-by: Chen Wang <wangchen20@iscas.ac.cn>

diff --git a/drivers/soc/sophgo/Kconfig b/drivers/soc/sophgo/Kconfig
index d97de4a41d5e4ce4d71e08d1aa5873ea9f50d259..45f78b270c91cd87ecf92747b1155293581fbff7 100644 (file)
--- a/drivers/soc/sophgo/Kconfig
+++ b/drivers/soc/sophgo/Kconfig
@@ -6,6 +6,19 @@
 if ARCH_SOPHGO || COMPILE_TEST
 menu "Sophgo SoC drivers"
 
+config SOPHGO_CV1800_RTCSYS
+       tristate "Sophgo CV1800 RTC MFD"
+       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 SOPHGO_SG2044_TOPSYS
        tristate "Sophgo SG2044 TOP syscon driver"
        select MFD_CORE

diff --git a/drivers/soc/sophgo/Makefile b/drivers/soc/sophgo/Makefile
index 171a2922d75bd4c97d5f5991cebc821b77798297..27f68df22c4d0ac65ecfb3503ff0f981ac7524b9 100644 (file)
--- a/drivers/soc/sophgo/Makefile
+++ b/drivers/soc/sophgo/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 
+obj-$(CONFIG_SOPHGO_CV1800_RTCSYS)     += cv1800-rtcsys.o
 obj-$(CONFIG_SOPHGO_SG2044_TOPSYS)     += sg2044-topsys.o

diff --git a/drivers/soc/sophgo/cv1800-rtcsys.c b/drivers/soc/sophgo/cv1800-rtcsys.c
new file mode 100644 (file)
index 0000000..fdae2e2
--- /dev/null
+++ b/drivers/soc/sophgo/cv1800-rtcsys.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Sophgo CV1800 series SoC RTC subsystem
+ *
+ * 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 = "cv1800b-rtc",
+               .num_resources = 1,
+               .resources = &cv1800_rtcsys_irq_resources[0],
+       },
+};
+
+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 subsystem driver");
+MODULE_LICENSE("GPL");