Only basic set/read time functionality is supported at the moment.
Tested with the samsung,coreprimevelte smartphone which contains this
PMIC and whose vendor kernel tree has also served as the sole reference
for this.
Signed-off-by: Karel Balej <balejk@xxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/rtc/Kconfig | 10 ++++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-88pm886.c | 97 +++++++++++++++++++++++++++++++++++++++
4 files changed, 109 insertions(+)
create mode 100644 drivers/rtc/rtc-88pm886.c
diff --git a/MAINTAINERS b/MAINTAINERS
index cc40a9d9b8cd..fe50a43f4e0d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13518,6 +13518,7 @@ F: Documentation/devicetree/bindings/mfd/marvell,88pm886-a1.yaml
F: drivers/input/misc/88pm886-onkey.c
F: drivers/mfd/88pm886.c
F: drivers/regulators/88pm886-regulator.c
+F: drivers/rtc/rtc-88pm886.c
F: include/linux/mfd/88pm886.h
MARVELL ARMADA 3700 PHY DRIVERS
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2a95b05982ad..6c9d51c585a2 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -182,6 +182,16 @@ config RTC_DRV_88PM80X
This driver can also be built as a module. If so, the module
will be called rtc-88pm80x.
+config RTC_DRV_88PM886
+ tristate "Marvell 88PM886 RTC driver"
+ depends on MFD_88PM886_PMIC
+ help
+ If you say yes here you will get support for the RTC function in the
+ Marvell 88PM886 chip.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-88pm886.
+
config RTC_DRV_ABB5ZES3
select REGMAP_I2C
tristate "Abracon AB-RTCMC-32.768kHz-B5ZE-S3"
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 3004e372f25f..0cd2c4943b7b 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_RTC_LIB_KUNIT_TEST) += lib_test.o
obj-$(CONFIG_RTC_DRV_88PM80X) += rtc-88pm80x.o
obj-$(CONFIG_RTC_DRV_88PM860X) += rtc-88pm860x.o
+obj-$(CONFIG_RTC_DRV_88PM886) += rtc-88pm886.o
obj-$(CONFIG_RTC_DRV_AB8500) += rtc-ab8500.o
obj-$(CONFIG_RTC_DRV_ABB5ZES3) += rtc-ab-b5ze-s3.o
obj-$(CONFIG_RTC_DRV_ABEOZ9) += rtc-ab-eoz9.o
diff --git a/drivers/rtc/rtc-88pm886.c b/drivers/rtc/rtc-88pm886.c
new file mode 100644
index 000000000000..57e9b0a66eed
--- /dev/null
+++ b/drivers/rtc/rtc-88pm886.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/limits.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#include <linux/mfd/88pm886.h>
+
+/*
+ * Time is calculated as the sum of a 32-bit read-only advancing counter and a
+ * writeable constant offset stored in the chip's spare registers.
+ */
+
+static int pm886_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct regmap *regmap = dev_get_drvdata(dev);
+ u32 time;
+ u32 buf;
+ int ret;
+
+ ret = regmap_bulk_read(regmap, PM886_REG_RTC_SPARE1, &buf, 4);
+ if (ret)
+ return ret;
+ time = buf;
+
+ ret = regmap_bulk_read(regmap, PM886_REG_RTC_CNT1, &buf, 4);
+ if (ret)
+ return ret;
+ time += buf;
+
+ rtc_time64_to_tm(time, tm);
+
+ return 0;
+}
+
+static int pm886_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct regmap *regmap = dev_get_drvdata(dev);
+ u32 buf;
+ int ret;
+
+ ret = regmap_bulk_read(regmap, PM886_REG_RTC_CNT1, &buf, 4);
+ if (ret)
+ return ret;
+
+ buf = rtc_tm_to_time64(tm) - buf;
+
+ return regmap_bulk_write(regmap, PM886_REG_RTC_SPARE1, &buf, 4);
+}
+
+static const struct rtc_class_ops pm886_rtc_ops = {
+ .read_time = pm886_rtc_read_time,
+ .set_time = pm886_rtc_set_time,
+};
+
+static int pm886_rtc_probe(struct platform_device *pdev)
+{
+ struct pm886_chip *chip = dev_get_drvdata(pdev->dev.parent);
+ struct device *dev = &pdev->dev;
+ struct rtc_device *rtc;
+ int ret;
+
+ platform_set_drvdata(pdev, chip->regmap);
+
+ rtc = devm_rtc_allocate_device(dev);
+ if (IS_ERR(rtc))
+ return dev_err_probe(dev, PTR_ERR(rtc),
+ "Failed to allocate RTC device\n");
+
+ rtc->ops = &pm886_rtc_ops;
+ rtc->range_max = U32_MAX;
+
+ ret = devm_rtc_register_device(rtc);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to register RTC device\n");
+
+ return 0;
+}
+
+static const struct platform_device_id pm886_rtc_id_table[] = {
+ { "88pm886-rtc", },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, pm886_rtc_id_table);
+
+static struct platform_driver pm886_rtc_driver = {
+ .driver = {
+ .name = "88pm886-rtc",
+ },
+ .probe = pm886_rtc_probe,
+ .id_table = pm886_rtc_id_table,
+};
+module_platform_driver(pm886_rtc_driver);
+
+MODULE_DESCRIPTION("Marvell 88PM886 RTC driver");
+MODULE_AUTHOR("Karel Balej <balejk@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
2.46.0
