[U-Boot] [PATCH] rtc: add Microcrystal RV-8803 driver
Michael Walle
michael at walle.cc
Mon May 27 20:23:21 UTC 2019
Signed-off-by: Michael Walle <michael at walle.cc>
---
Btw if anybody notices the compatible string difference to the rv3029
driver, ie mc,rv3029 vs microcrystal,rv8803. The "mc" prefix is actually
the legacy one.
drivers/rtc/Kconfig | 10 +++
drivers/rtc/Makefile | 1 +
drivers/rtc/rv8803.c | 167 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 178 insertions(+)
create mode 100644 drivers/rtc/rv8803.c
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index fd0009b2e2..532e94d337 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -70,6 +70,16 @@ config RTC_RV3029
This driver supports reading and writing the RTC/calendar and the
battery-baced SRAM section.
+config RTC_RV8803
+ bool "Enable RV8803 driver"
+ depends on DM_RTC
+ help
+ The Micro Crystal RV8803 is a high accuracy, ultra-low power I2C
+ Real Time Clock (RTC) with temperature compensation.
+
+ This driver supports reading and writing the RTC/calendar and
+ detects total power failures.
+
config RTC_RX8010SJ
bool "Enable RX8010SJ driver"
depends on DM_RTC
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 1724602f1c..915adb87fe 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_RTC_PL031) += pl031.o
obj-$(CONFIG_RTC_PT7C4338) += pt7c4338.o
obj-$(CONFIG_RTC_RS5C372A) += rs5c372.o
obj-$(CONFIG_RTC_RV3029) += rv3029.o
+obj-$(CONFIG_RTC_RV8803) += rv8803.o
obj-$(CONFIG_RTC_RX8025) += rx8025.o
obj-$(CONFIG_RTC_RX8010SJ) += rx8010sj.o
obj-$(CONFIG_RTC_S3C24X0) += s3c24x0_rtc.o
diff --git a/drivers/rtc/rv8803.c b/drivers/rtc/rv8803.c
new file mode 100644
index 0000000000..2ab40f0833
--- /dev/null
+++ b/drivers/rtc/rv8803.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Date & Time support for Micro Crystal RV-8803-C7.
+ *
+ * based on ds1307.c which is
+ * (C) Copyright 2001, 2002, 2003
+ * Wolfgang Denk, DENX Software Engineering, wd at denx.de.
+ * Keith Outwater, keith_outwater at mvis.com`
+ * Steven Scholz, steven.scholz at imc-berlin.de
+ *
+ */
+
+#include <common.h>
+#include <command.h>
+#include <dm.h>
+#include <rtc.h>
+#include <i2c.h>
+
+/*
+ * RTC register addresses
+ */
+#define RTC_SEC_REG_ADDR 0x00
+#define RTC_MIN_REG_ADDR 0x01
+#define RTC_HR_REG_ADDR 0x02
+#define RTC_DAY_REG_ADDR 0x03
+#define RTC_DATE_REG_ADDR 0x04
+#define RTC_MON_REG_ADDR 0x05
+#define RTC_YR_REG_ADDR 0x06
+
+#define RTC_FLAG_REG_ADDR 0x0E
+#define RTC_FLAG_BIT_V1F BIT(0)
+#define RTC_FLAG_BIT_V2F BIT(1)
+
+#define RTC_CTL_REG_ADDR 0x0F
+#define RTC_CTL_BIT_RST BIT(0)
+
+static int rv8803_rtc_set(struct udevice *dev, const struct rtc_time *tm)
+{
+ int ret;
+ u8 buf[7];
+
+ debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
+ tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+ if (tm->tm_year < 2000 || tm->tm_year > 2099)
+ printf("WARNING: year should be between 2000 and 2099!\n");
+
+ buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
+ buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
+ buf[RTC_DAY_REG_ADDR] = 1 << (tm->tm_wday & 0x7);
+ buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
+ buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
+ buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
+ buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
+
+ ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int rv8803_rtc_get(struct udevice *dev, struct rtc_time *tm)
+{
+ int ret;
+ u8 buf[7];
+ int flags;
+
+ flags = dm_i2c_reg_read(dev, RTC_FLAG_REG_ADDR);
+ if (flags < 0)
+ return flags;
+ debug("%s: flags=%Xh\n", __func__, flags);
+
+ if (flags & RTC_FLAG_BIT_V1F)
+ printf("### Warning: temperature compensation has stopped\n");
+
+ if (flags & RTC_FLAG_BIT_V2F) {
+ printf("### Warning: Voltage low, data is invalid\n");
+ return -1;
+ }
+
+ ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+
+ tm->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
+ tm->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
+ tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
+ tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
+ tm->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
+ tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000;
+ tm->tm_wday = fls(buf[RTC_DAY_REG_ADDR] & 0x7F) - 1;
+ tm->tm_yday = 0;
+ tm->tm_isdst = 0;
+
+ debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
+ tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
+ tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+ return 0;
+}
+
+static int rv8803_rtc_reset(struct udevice *dev)
+{
+ int ret;
+ struct rtc_time tmp = {
+ .tm_year = 2000,
+ .tm_mon = 1,
+ .tm_mday = 1,
+ .tm_hour = 0,
+ .tm_min = 0,
+ .tm_sec = 0,
+ };
+
+ /* assert reset */
+ ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, RTC_CTL_BIT_RST);
+ if (ret < 0)
+ return ret;
+
+ /* clear all flags */
+ ret = dm_i2c_reg_write(dev, RTC_FLAG_REG_ADDR, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = rv8803_rtc_set(dev, &tmp);
+ if (ret < 0)
+ return ret;
+
+ /* clear reset */
+ ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, 0);
+ if (ret < 0)
+ return ret;
+
+ debug("RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
+ tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
+ tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
+
+ return 0;
+}
+
+static int rv8803_probe(struct udevice *dev)
+{
+ i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
+ DM_I2C_CHIP_WR_ADDRESS);
+
+ return 0;
+}
+
+static const struct rtc_ops rv8803_rtc_ops = {
+ .get = rv8803_rtc_get,
+ .set = rv8803_rtc_set,
+ .reset = rv8803_rtc_reset,
+};
+
+static const struct udevice_id rv8803_rtc_ids[] = {
+ { .compatible = "microcrystal,rv8803", },
+ { }
+};
+
+U_BOOT_DRIVER(rtc_rv8803) = {
+ .name = "rtc-rv8803",
+ .id = UCLASS_RTC,
+ .probe = rv8803_probe,
+ .of_match = rv8803_rtc_ids,
+ .ops = &rv8803_rtc_ops,
+};
--
2.11.0
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