rtc: adding RX8010SJ rtc driver

Add a new driver for RX8010SJ rtc chip. The driver implements both
formats of U-Boot driver model.

Signed-off-by: Nandor Han <nandor.han@ge.com>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

3 files changed, 385 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2964bb2..95ac031 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -30,6 +30,12 @@ config RTC_DS1307
 	  Support for Dallas Semiconductor (now Maxim) DS1307 and DS1338/9 and
 	  compatible Real Time Clock devices.
 
+config RTC_RX8010SJ
+	bool "Enable RX8010SJ driver"
+	depends on DM_RTC
+	help
+	  Support for Epson RX8010SJ Real Time Clock devices.
+
 config RTC_S35392A
 	bool "Enable S35392A driver"
 	select BITREVERSE
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 7a8f97a..9723fb7 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_RTC_PT7C4338) += pt7c4338.o
 obj-$(CONFIG_RTC_RS5C372A) += rs5c372.o
 obj-$(CONFIG_RTC_RV3029) += rv3029.o
 obj-$(CONFIG_RTC_RX8025) += rx8025.o
+obj-$(CONFIG_RTC_RX8010SJ) += rx8010sj.o
 obj-$(CONFIG_RTC_S3C24X0) += s3c24x0_rtc.o
 obj-$(CONFIG_RTC_S35392A) += s35392a.o
 obj-$(CONFIG_SANDBOX) += sandbox_rtc.o
diff --git a/drivers/rtc/rx8010sj.c b/drivers/rtc/rx8010sj.c
new file mode 100644
index 0000000..81560e1
--- /dev/null
+++ b/drivers/rtc/rx8010sj.c
@@ -0,0 +1,378 @@
+/*
+ * Epson RX8010 RTC driver.
+ *
+ * Copyright (c) 2017, General Electric Company
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <command.h>
+#include <common.h>
+#include <dm.h>
+#include <i2c.h>
+#include <rtc.h>
+
+/*---------------------------------------------------------------------*/
+/* #undef DEBUG_RTC */
+
+#ifdef DEBUG_RTC
+#define DEBUGR(fmt, args...) printf(fmt, ##args)
+#else
+#define DEBUGR(fmt, args...)
+#endif
+/*---------------------------------------------------------------------*/
+
+#ifndef CONFIG_SYS_I2C_RTC_ADDR
+# define CONFIG_SYS_I2C_RTC_ADDR	0x32
+#endif
+
+/*
+ * RTC register addresses
+ */
+#define RX8010_SEC     0x10
+#define RX8010_MIN     0x11
+#define RX8010_HOUR    0x12
+#define RX8010_WDAY    0x13
+#define RX8010_MDAY    0x14
+#define RX8010_MONTH   0x15
+#define RX8010_YEAR    0x16
+#define RX8010_YEAR    0x16
+#define RX8010_RESV17  0x17
+#define RX8010_ALMIN   0x18
+#define RX8010_ALHOUR  0x19
+#define RX8010_ALWDAY  0x1A
+#define RX8010_TCOUNT0 0x1B
+#define RX8010_TCOUNT1 0x1C
+#define RX8010_EXT     0x1D
+#define RX8010_FLAG    0x1E
+#define RX8010_CTRL    0x1F
+/* 0x20 to 0x2F are user registers */
+#define RX8010_RESV30  0x30
+#define RX8010_RESV31  0x32
+#define RX8010_IRQ     0x32
+
+#define RX8010_EXT_WADA  BIT(3)
+
+#define RX8010_FLAG_VLF  BIT(1)
+#define RX8010_FLAG_AF   BIT(3)
+#define RX8010_FLAG_TF   BIT(4)
+#define RX8010_FLAG_UF   BIT(5)
+
+#define RX8010_CTRL_AIE  BIT(3)
+#define RX8010_CTRL_UIE  BIT(5)
+#define RX8010_CTRL_STOP BIT(6)
+#define RX8010_CTRL_TEST BIT(7)
+
+#define RX8010_ALARM_AE  BIT(7)
+
+#ifdef CONFIG_DM_RTC
+
+#define DEV_TYPE struct udevice
+
+#else
+
+/* Local udevice */
+struct ludevice {
+	u8 chip;
+};
+
+#define DEV_TYPE struct ludevice
+
+#endif
+
+static int rx8010sj_rtc_read8(DEV_TYPE *dev, unsigned int reg)
+{
+	u8 val;
+	int ret;
+
+#ifdef CONFIG_DM_RTC
+	ret = dm_i2c_read(dev, reg, &val, sizeof(val));
+#else
+	ret = i2c_read(dev->chip, reg, 1, &val, 1);
+#endif
+
+	return ret < 0 ? ret : val;
+}
+
+static int rx8010sj_rtc_write8(DEV_TYPE *dev, unsigned int reg, int val)
+{
+	int ret;
+	u8 lval = val;
+
+#ifdef CONFIG_DM_RTC
+	ret = dm_i2c_write(dev, reg, &lval, 1);
+#else
+	ret = i2c_write(dev->chip, reg, 1, &lval, 1);
+#endif
+
+	return ret < 0 ? ret : 0;
+}
+
+static int validate_time(const struct rtc_time *tm)
+{
+	if ((tm->tm_year < 2000) || (tm->tm_year > 2099))
+		return -EINVAL;
+
+	if ((tm->tm_mon < 1) || (tm->tm_mon > 12))
+		return -EINVAL;
+
+	if ((tm->tm_mday < 1) || (tm->tm_mday > 31))
+		return -EINVAL;
+
+	if ((tm->tm_wday < 0) || (tm->tm_wday > 6))
+		return -EINVAL;
+
+	if ((tm->tm_hour < 0) || (tm->tm_hour > 23))
+		return -EINVAL;
+
+	if ((tm->tm_min < 0) || (tm->tm_min > 59))
+		return -EINVAL;
+
+	if ((tm->tm_sec < 0) || (tm->tm_sec > 59))
+		return -EINVAL;
+
+	return 0;
+}
+
+void rx8010sj_rtc_init(DEV_TYPE *dev)
+{
+	u8 ctrl[2];
+	int need_clear = 0, ret = 0;
+
+	/* Initialize reserved registers as specified in datasheet */
+	ret = rx8010sj_rtc_write8(dev, RX8010_RESV17, 0xD8);
+	if (ret < 0)
+		goto error;
+
+	ret = rx8010sj_rtc_write8(dev, RX8010_RESV30, 0x00);
+	if (ret < 0)
+		goto error;
+
+	ret = rx8010sj_rtc_write8(dev, RX8010_RESV31, 0x08);
+	if (ret < 0)
+		goto error;
+
+	ret = rx8010sj_rtc_write8(dev, RX8010_IRQ, 0x00);
+	if (ret < 0)
+		goto error;
+
+	for (int i = 0; i < 2; i++) {
+		ret = rx8010sj_rtc_read8(dev, RX8010_FLAG + i);
+		if (ret < 0)
+			goto error;
+
+		ctrl[i] = ret;
+	}
+
+	if (ctrl[0] & RX8010_FLAG_VLF)
+		printf("RTC low voltage detected\n");
+
+	if (ctrl[0] & RX8010_FLAG_AF) {
+		printf("Alarm was detected\n");
+		need_clear = 1;
+	}
+
+	if (ctrl[0] & RX8010_FLAG_TF)
+		need_clear = 1;
+
+	if (ctrl[0] & RX8010_FLAG_UF)
+		need_clear = 1;
+
+	if (need_clear) {
+		ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
+		ret = rx8010sj_rtc_write8(dev, RX8010_FLAG, ctrl[0]);
+		if (ret < 0)
+			goto error;
+	}
+
+	return;
+
+error:
+	printf("Error rtc init.\n");
+}
+
+/* Get the current time from the RTC */
+static int rx8010sj_rtc_get(DEV_TYPE *dev, struct rtc_time *tmp)
+{
+	u8 date[7];
+	int flagreg;
+	int ret;
+
+	flagreg = rx8010sj_rtc_read8(dev, RX8010_FLAG);
+	if (flagreg < 0) {
+		DEBUGR("Error reading from RTC. err: %d\n", flagreg);
+		return -EIO;
+	}
+
+	if (flagreg & RX8010_FLAG_VLF) {
+		DEBUGR("RTC low voltage detected\n");
+		return -EINVAL;
+	}
+
+	for (int i = 0; i < 7; i++) {
+		ret = rx8010sj_rtc_read8(dev, RX8010_SEC + i);
+		if (ret < 0) {
+			DEBUGR("Error reading from RTC. err: %d\n", ret);
+			return -EIO;
+		}
+		date[i] = ret;
+	}
+
+	tmp->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
+	tmp->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
+	tmp->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
+	tmp->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
+	tmp->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f);
+	tmp->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 2000;
+	tmp->tm_wday = 0;
+	tmp->tm_yday = 0;
+	tmp->tm_isdst = 0;
+
+	DEBUGR("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
+	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
+	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
+
+	return 0;
+}
+
+/* Set the RTC */
+static int rx8010sj_rtc_set(DEV_TYPE *dev, const struct rtc_time *tm)
+{
+	u8 date[7];
+	int ctrl, flagreg;
+	int ret;
+
+	ret = validate_time(tm);
+	if (ret < 0)
+		return -EINVAL;
+
+	/* set STOP bit before changing clock/calendar */
+	ctrl = rx8010sj_rtc_read8(dev, RX8010_CTRL);
+	if (ctrl < 0)
+		return ctrl;
+	ret = rx8010sj_rtc_write8(dev, RX8010_CTRL, ctrl | RX8010_CTRL_STOP);
+	if (ret < 0)
+		return ret;
+
+	date[RX8010_SEC - RX8010_SEC] = bin2bcd(tm->tm_sec);
+	date[RX8010_MIN - RX8010_SEC] = bin2bcd(tm->tm_min);
+	date[RX8010_HOUR - RX8010_SEC] = bin2bcd(tm->tm_hour);
+	date[RX8010_MDAY - RX8010_SEC] = bin2bcd(tm->tm_mday);
+	date[RX8010_MONTH - RX8010_SEC] = bin2bcd(tm->tm_mon);
+	date[RX8010_YEAR - RX8010_SEC] = bin2bcd(tm->tm_year - 2000);
+	date[RX8010_WDAY - RX8010_SEC] = bin2bcd(tm->tm_wday);
+
+	for (int i = 0; i < 7; i++) {
+		ret = rx8010sj_rtc_write8(dev, RX8010_SEC + i, date[i]);
+		if (ret < 0) {
+			DEBUGR("Error writing to RTC. err: %d\n", ret);
+			return -EIO;
+		}
+	}
+
+	/* clear STOP bit after changing clock/calendar */
+	ctrl = rx8010sj_rtc_read8(dev, RX8010_CTRL);
+	if (ctrl < 0)
+		return ctrl;
+
+	ret = rx8010sj_rtc_write8(dev, RX8010_CTRL, ctrl & ~RX8010_CTRL_STOP);
+	if (ret < 0)
+		return ret;
+
+	flagreg = rx8010sj_rtc_read8(dev, RX8010_FLAG);
+	if (flagreg < 0)
+		return flagreg;
+
+	if (flagreg & RX8010_FLAG_VLF)
+		ret = rx8010sj_rtc_write8(dev, RX8010_FLAG,
+					  flagreg & ~RX8010_FLAG_VLF);
+
+	return 0;
+}
+
+/* Reset the RTC. */
+static int rx8010sj_rtc_reset(DEV_TYPE *dev)
+{
+	/* Not needed */
+	return 0;
+}
+
+#ifndef CONFIG_DM_RTC
+
+int rtc_get(struct rtc_time *tm)
+{
+	struct ludevice dev = {
+			.chip = CONFIG_SYS_I2C_RTC_ADDR,
+	};
+
+	return rx8010sj_rtc_get(&dev, tm);
+}
+
+int rtc_set(struct rtc_time *tm)
+{
+	struct ludevice dev = {
+			.chip = CONFIG_SYS_I2C_RTC_ADDR,
+	};
+
+	return rx8010sj_rtc_set(&dev, tm);
+}
+
+void rtc_reset(void)
+{
+	struct ludevice dev = {
+			.chip = CONFIG_SYS_I2C_RTC_ADDR,
+	};
+
+	rx8010sj_rtc_reset(&dev);
+}
+
+void rtc_init(void)
+{
+	struct ludevice dev = {
+			.chip = CONFIG_SYS_I2C_RTC_ADDR,
+	};
+
+	rx8010sj_rtc_init(&dev);
+}
+
+#else
+
+static int rx8010sj_probe(struct udevice *dev)
+{
+	rx8010sj_rtc_init(&dev);
+
+	return 0;
+}
+
+static const struct rtc_ops rx8010sj_rtc_ops = {
+	.get = rx8010sj_rtc_get,
+	.set = rx8010sj_rtc_set,
+	.read8 = rx8010sj_rtc_read8,
+	.write8 = rx8010sj_rtc_write8,
+	.reset = rx8010sj_rtc_reset,
+};
+
+static const struct udevice_id rx8010sj_rtc_ids[] = {
+	{ .compatible = "epson,rx8010sj-rtc" },
+	{ }
+};
+
+U_BOOT_DRIVER(rx8010sj_rtc) = {
+	.name	  = "rx8010sj_rtc",
+	.id	      = UCLASS_RTC,
+	.probe    = rx8010sj_probe,
+	.of_match = rx8010sj_rtc_ids,
+	.ops	  = &rx8010sj_rtc_ops,
+};
+
+#endif