[PATCH v2] rtc: add support for rv3028 rtc

Heiko Schocher
2021-03-10T07:15:00Z

Add support for rtc3028 rtc from microcrystal.
based on linux dirver:
commit a38fd8748464: ("Linux 5.12-rc2")

Signed-off-by: Heiko Schocher <hs@denx.de>

Reviewed-by: Stefan Roese <sr@denx.de>
---
Driver is based on code in linux, but with already
corrected weekday usage. Linux codes the weekday
bitwise, while the weekday register has only 3 valid
bits as the app manual [1] says:

This register holds the current day of the week. Each value represents
one weekday that is assigned by the user. Values will range from 0 to 6
The weekday counter is simply a 3-bit counter which counts up to 6
and then resets to 0.

[1] https://www.microcrystal.com/fileadmin/Media/Products/RTC/App.Manual/RV-3028-C7_App-Manual.pdf

This is not a big problem, as userspace never use weekday.
Nevertheless, sent an update for the linux driver also:

https://marc.info/?l=linux-rtc&m=161529769106774&w=2

azure build:
https://dev.azure.com/hs0298/hs/_build/results?buildId=64&view=results

Changes in v2:
- add comments from Stefan
- start sentence with upper-case
- remove not needed includes, thanks!
- add Reviewed-by from Stefan

drivers/rtc/Kconfig | 6 ++
drivers/rtc/Makefile | 1 +
drivers/rtc/rv3028.c | 208 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 215 insertions(+)
create mode 100644 drivers/rtc/rv3028.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index aa6d90158c..e451308b40 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -95,6 +95,12 @@ config RTC_PCF8563
If you say yes here you get support for the Philips PCF8563 RTC
and compatible chips.

+config RTC_RV3028
+ bool "Enable RV3028 driver"
+ depends on DM_RTC
+ help
+ The MicroCrystal RV3028 is a I2C Real Time Clock (RTC)
+
config RTC_RV3029
bool "Enable RV3029 driver"
depends on DM_RTC
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 6a45a9c874..e7acd76266 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_RTC_PCF2127) += pcf2127.o
obj-$(CONFIG_RTC_PL031) += pl031.o
obj-$(CONFIG_RTC_PT7C4338) += pt7c4338.o
obj-$(CONFIG_RTC_RS5C372A) += rs5c372.o
+obj-$(CONFIG_RTC_RV3028) += rv3028.o
obj-$(CONFIG_RTC_RV3029) += rv3029.o
obj-$(CONFIG_RTC_RV8803) += rv8803.o
obj-$(CONFIG_RTC_RX8025) += rx8025.o
diff --git a/drivers/rtc/rv3028.c b/drivers/rtc/rv3028.c
new file mode 100644
index 0000000000..9f63afc14a
--- /dev/null
+++ b/drivers/rtc/rv3028.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RTC driver for the Micro Crystal RV3028
+ *
+ * based on linux driver from
+ * Copyright (C) 2019 Micro Crystal SA
+ *
+ * Alexandre Belloni <alexandre.belloni@bootlin.com>
+ *
+ */
+
+#include <dm.h>
+#include <i2c.h>
+#include <rtc.h>
+
+#define RV3028_SEC 0x00
+#define RV3028_MIN 0x01
+#define RV3028_HOUR 0x02
+#define RV3028_WDAY 0x03
+#define RV3028_DAY 0x04
+#define RV3028_MONTH 0x05
+#define RV3028_YEAR 0x06
+#define RV3028_ALARM_MIN 0x07
+#define RV3028_ALARM_HOUR 0x08
+#define RV3028_ALARM_DAY 0x09
+#define RV3028_STATUS 0x0E
+#define RV3028_CTRL1 0x0F
+#define RV3028_CTRL2 0x10
+#define RV3028_EVT_CTRL 0x13
+#define RV3028_TS_COUNT 0x14
+#define RV3028_TS_SEC 0x15
+#define RV3028_RAM1 0x1F
+#define RV3028_EEPROM_ADDR 0x25
+#define RV3028_EEPROM_DATA 0x26
+#define RV3028_EEPROM_CMD 0x27
+#define RV3028_CLKOUT 0x35
+#define RV3028_OFFSET 0x36
+#define RV3028_BACKUP 0x37
+
+#define RV3028_STATUS_PORF BIT(0)
+#define RV3028_STATUS_EVF BIT(1)
+#define RV3028_STATUS_AF BIT(2)
+#define RV3028_STATUS_TF BIT(3)
+#define RV3028_STATUS_UF BIT(4)
+#define RV3028_STATUS_BSF BIT(5)
+#define RV3028_STATUS_CLKF BIT(6)
+#define RV3028_STATUS_EEBUSY BIT(7)
+
+#define RV3028_CLKOUT_FD_MASK GENMASK(2, 0)
+#define RV3028_CLKOUT_PORIE BIT(3)
+#define RV3028_CLKOUT_CLKSY BIT(6)
+#define RV3028_CLKOUT_CLKOE BIT(7)
+
+#define RV3028_CTRL1_EERD BIT(3)
+#define RV3028_CTRL1_WADA BIT(5)
+
+#define RV3028_CTRL2_RESET BIT(0)
+#define RV3028_CTRL2_12_24 BIT(1)
+#define RV3028_CTRL2_EIE BIT(2)
+#define RV3028_CTRL2_AIE BIT(3)
+#define RV3028_CTRL2_TIE BIT(4)
+#define RV3028_CTRL2_UIE BIT(5)
+#define RV3028_CTRL2_TSE BIT(7)
+
+#define RV3028_EVT_CTRL_TSR BIT(2)
+
+#define RV3028_EEPROM_CMD_UPDATE 0x11
+#define RV3028_EEPROM_CMD_WRITE 0x21
+#define RV3028_EEPROM_CMD_READ 0x22
+
+#define RV3028_EEBUSY_POLL 10000
+#define RV3028_EEBUSY_TIMEOUT 100000
+
+#define RV3028_BACKUP_TCE BIT(5)
+#define RV3028_BACKUP_TCR_MASK GENMASK(1, 0)
+
+#define OFFSET_STEP_PPT 953674
+
+#define RTC_RV3028_LEN 7
+
+static int rv3028_rtc_get(struct udevice *dev, struct rtc_time *tm)
+{
+ u8 regs[RTC_RV3028_LEN];
+ u8 status;
+ int ret;
+
+ ret = dm_i2c_read(dev, RV3028_STATUS, &status, 1);
+ if (ret < 0) {
+ printf("%s: error reading RTC status: %x\n", __func__, ret);
+ return -EIO;
+ }
+
+ if (status & RV3028_STATUS_PORF) {
+ printf("Voltage low, data is invalid.\n");
+ return -EINVAL;
+ }
+
+ ret = dm_i2c_read(dev, RV3028_SEC, regs, sizeof(regs));
+ if (ret < 0) {
+ printf("%s: error reading RTC: %x\n", __func__, ret);
+ return -EIO;
+ }
+
+ tm->tm_sec = bcd2bin(regs[RV3028_SEC] & 0x7f);
+ tm->tm_min = bcd2bin(regs[RV3028_MIN] & 0x7f);
+ tm->tm_hour = bcd2bin(regs[RV3028_HOUR] & 0x3f);
+ tm->tm_wday = regs[RV3028_WDAY] & 0x7;
+ tm->tm_mday = bcd2bin(regs[RV3028_DAY] & 0x3f);
+ tm->tm_mon = bcd2bin(regs[RV3028_MONTH] & 0x1f);
+ tm->tm_year = bcd2bin(regs[RV3028_YEAR]) + 2000;
+ tm->tm_yday = 0;
+ tm->tm_isdst = 0;
+
+ debug("%s: %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n",
+ __func__, 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 rv3028_rtc_set(struct udevice *dev, const struct rtc_time *tm)
+{
+ u8 regs[RTC_RV3028_LEN];
+ u8 status;
+ int ret;
+
+ debug("%s: %4d-%02d-%02d (wday=%d( %2d:%02d:%02d\n",
+ __func__, 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) {
+ printf("%s: year %d (before 2000) not supported\n",
+ __func__, tm->tm_year);
+ return -EINVAL;
+ }
+
+ regs[RV3028_SEC] = bin2bcd(tm->tm_sec);
+ regs[RV3028_MIN] = bin2bcd(tm->tm_min);
+ regs[RV3028_HOUR] = bin2bcd(tm->tm_hour);
+ regs[RV3028_WDAY] = tm->tm_wday;
+ regs[RV3028_DAY] = bin2bcd(tm->tm_mday);
+ regs[RV3028_MONTH] = bin2bcd(tm->tm_mon);
+ regs[RV3028_YEAR] = bin2bcd(tm->tm_year - 2000);
+
+ ret = dm_i2c_write(dev, RV3028_SEC, regs, sizeof(regs));
+ if (ret) {
+ printf("%s: set rtc error: %d\n", __func__, ret);
+ return ret;
+ }
+
+ ret = dm_i2c_read(dev, RV3028_STATUS, &status, 1);
+ if (ret < 0) {
+ printf("%s: error reading RTC status: %x\n", __func__, ret);
+ return -EIO;
+ }
+ status |= RV3028_STATUS_PORF;
+ return dm_i2c_write(dev, RV3028_STATUS, &status, 1);
+}
+
+static int rv3028_rtc_reset(struct udevice *dev)
+{
+ return 0;
+}
+
+static int rv3028_rtc_read8(struct udevice *dev, unsigned int reg)
+{
+ u8 data;
+ int ret;
+
+ ret = dm_i2c_read(dev, reg, &data, sizeof(data));
+ return ret < 0 ? ret : data;
+}
+
+static int rv3028_rtc_write8(struct udevice *dev, unsigned int reg, int val)
+{
+ u8 data = val;
+
+ return dm_i2c_write(dev, reg, &data, 1);
+}
+
+static int rv3028_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 rv3028_rtc_ops = {
+ .get = rv3028_rtc_get,
+ .set = rv3028_rtc_set,
+ .read8 = rv3028_rtc_read8,
+ .write8 = rv3028_rtc_write8,
+ .reset = rv3028_rtc_reset,
+};
+
+static const struct udevice_id rv3028_rtc_ids[] = {
+ { .compatible = "microcrystal,rv3028" },
+ { }
+};
+
+U_BOOT_DRIVER(rtc_rv3028) = {
+ .name = "rtc-rv3028",
+ .id = UCLASS_RTC,
+ .probe = rv3028_probe,
+ .of_match = rv3028_rtc_ids,
+ .ops = &rv3028_rtc_ops,
+};
--
2.29.2