With this driver, mainline Linux can keep its time and date in sync with
the vendor kernel.
Advanced functionality like alarm and automatic power-on is not yet
supported.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@xxxxxxx>
---
drivers/rtc/Kconfig | 4 ++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-ntxec.c | 115 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 120 insertions(+)
create mode 100644 drivers/rtc/rtc-ntxec.c
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index b54d87d45c89b..2310d08933f9c 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1300,6 +1300,10 @@ config RTC_DRV_CROS_EC
This driver can also be built as a module. If so, the module
will be called rtc-cros-ec.
+config RTC_DRV_NTXEC
+ tristate "Netronix embedded controller RTC driver"
+ depends on MFD_NTXEC
+
comment "on-CPU RTC drivers"
config RTC_DRV_ASM9260
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 0721752c6ed4c..8653d04aefa99 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -111,6 +111,7 @@ obj-$(CONFIG_RTC_DRV_MT7622) += rtc-mt7622.o
obj-$(CONFIG_RTC_DRV_MV) += rtc-mv.o
obj-$(CONFIG_RTC_DRV_MXC) += rtc-mxc.o
obj-$(CONFIG_RTC_DRV_MXC_V2) += rtc-mxc_v2.o
+obj-$(CONFIG_RTC_DRV_NTXEC) += rtc-ntxec.o
obj-$(CONFIG_RTC_DRV_OMAP) += rtc-omap.o
obj-$(CONFIG_RTC_DRV_OPAL) += rtc-opal.o
obj-$(CONFIG_RTC_DRV_PALMAS) += rtc-palmas.o
diff --git a/drivers/rtc/rtc-ntxec.c b/drivers/rtc/rtc-ntxec.c
new file mode 100644
index 0000000000000..44d5a5eedb597
--- /dev/null
+++ b/drivers/rtc/rtc-ntxec.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright 2020 Jonathan Neuschäfer
+
+#include <linux/rtc.h>
+#include <linux/mfd/ntxec.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+struct ntxec_rtc {
+ struct device *dev;
+ struct ntxec *ec;
+};
+
+#define NTXEC_WRITE_YEAR 0x10
+#define NTXEC_WRITE_MONTH 0x11
+#define NTXEC_WRITE_DAY 0x12
+#define NTXEC_WRITE_HOUR 0x13
+#define NTXEC_WRITE_MINUTE 0x14
+#define NTXEC_WRITE_SECOND 0x15
+
+#define NTXEC_READ_YM 0x20
+#define NTXEC_READ_DH 0x21
+#define NTXEC_READ_MS 0x22
+
+
+static int ntxec_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct ntxec_rtc *rtc = dev_get_drvdata(dev);
+ int res;
+
+ res = ntxec_read16(rtc->ec, NTXEC_READ_YM);
+ if (res < 0)
+ return res;
+
+ tm->tm_year = (res >> 8) + 100;
+ tm->tm_mon = (res & 0xff) - 1;
+
+ res = ntxec_read16(rtc->ec, NTXEC_READ_DH);
+ if (res < 0)
+ return res;
+
+ tm->tm_mday = res >> 8;
+ tm->tm_hour = res & 0xff;
+
+ res = ntxec_read16(rtc->ec, NTXEC_READ_MS);
+ if (res < 0)
+ return res;
+
+ tm->tm_min = res >> 8;
+ tm->tm_sec = res & 0xff;
+
+ return 0;
+}
+
+static int ntxec_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct ntxec_rtc *rtc = dev_get_drvdata(dev);
+ int res = 0;
+
+ res |= ntxec_write8(rtc->ec, NTXEC_WRITE_YEAR, tm->tm_year - 100);
+ res |= ntxec_write8(rtc->ec, NTXEC_WRITE_MONTH, tm->tm_mon + 1);
+ res |= ntxec_write8(rtc->ec, NTXEC_WRITE_DAY, tm->tm_mday);
+ res |= ntxec_write8(rtc->ec, NTXEC_WRITE_HOUR, tm->tm_hour);
+ res |= ntxec_write8(rtc->ec, NTXEC_WRITE_MINUTE, tm->tm_min);
+ res |= ntxec_write8(rtc->ec, NTXEC_WRITE_SECOND, tm->tm_sec);
+
+ return (res < 0)? -EIO : 0;
+}
+
+static const struct rtc_class_ops ntxec_rtc_ops = {
+ .read_time = ntxec_read_time,
+ .set_time = ntxec_set_time,
+};
+
+static int ntxec_rtc_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtcdev;
+ struct ntxec_rtc *rtc;
+
+ rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+
+ rtc->dev = &pdev->dev;
+ rtc->ec = dev_get_drvdata(pdev->dev.parent);
+ platform_set_drvdata(pdev, rtc);
+
+ rtcdev = devm_rtc_device_register(&pdev->dev, "ntxec-rtc",
+ &ntxec_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtcdev))
+ return PTR_ERR(rtc);
+
+ return 0;
+}
+
+static const struct of_device_id ntxec_rtc_of_match[] = {
+ { .compatible = "netronix,ntxec-rtc" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ntxec_rtc_of_match);
+
+static struct platform_driver ntxec_rtc_driver = {
+ .driver = {
+ .name = "ntxec-rtc",
+ .of_match_table = ntxec_rtc_of_match,
+ },
+ .probe = ntxec_rtc_probe,
+};
+module_platform_driver(ntxec_rtc_driver);
+
+MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@xxxxxxx>");
+MODULE_DESCRIPTION("RTC driver for Netronix EC");
+MODULE_LICENSE("GPL");
--
2.27.0
