rtc: bd70528: add BD71828 support

ROHM BD71828 PMIC RTC block is from many parts similar to one
on BD70528. Support BD71828 RTC using BD70528 RTC driver and
avoid re-inventing the wheel.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/rtc/Kconfig

@@ -498,12 +498,13 @@ config RTC_DRV_M41T80_WDT
 	help
 	  If you say Y here you will get support for the
 	  watchdog timer in the ST M41T60 and M41T80 RTC chips series.
+
 config RTC_DRV_BD70528
 	tristate "ROHM BD70528 PMIC RTC"
 	depends on MFD_ROHM_BD70528 && (BD70528_WATCHDOG || !BD70528_WATCHDOG)
 	help
 	  If you say Y here you will get support for the RTC
-	  on ROHM BD70528 Power Management IC.
+	  block on ROHM BD70528 and BD71828 Power Management IC.
 
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-bd70528.

include/linux/mfd/rohm-bd70528.h

@@ -7,6 +7,7 @@
 #include <linux/bits.h>
 #include <linux/device.h>
 #include <linux/mfd/rohm-generic.h>
+#include <linux/mfd/rohm-shared.h>
 #include <linux/regmap.h>
 
 enum {
@@ -307,17 +308,6 @@ enum {
 
 /* RTC masks to mask out reserved bits */
 
-#define BD70528_MASK_RTC_SEC		0x7f
-#define BD70528_MASK_RTC_MINUTE		0x7f
-#define BD70528_MASK_RTC_HOUR_24H	0x80
-#define BD70528_MASK_RTC_HOUR_PM	0x20
-#define BD70528_MASK_RTC_HOUR		0x3f
-#define BD70528_MASK_RTC_DAY		0x3f
-#define BD70528_MASK_RTC_WEEK		0x07
-#define BD70528_MASK_RTC_MONTH		0x1f
-#define BD70528_MASK_RTC_YEAR		0xff
-#define BD70528_MASK_RTC_COUNT_L	0x7f
-
 #define BD70528_MASK_ELAPSED_TIMER_EN	0x1
 /* Mask second, min and hour fields
  * HW would support ALM irq for over 24h
@@ -326,7 +316,6 @@ enum {
  * wake-up we limit ALM to 24H and only
  * unmask sec, min and hour
  */
-#define BD70528_MASK_ALM_EN		0x7
 #define BD70528_MASK_WAKE_EN		0x1
 
 /* WDT masks */

include/linux/mfd/rohm-bd71828.h

@@ -5,6 +5,7 @@
 #define __LINUX_MFD_BD71828_H__
 
 #include <linux/mfd/rohm-generic.h>
+#include <linux/mfd/rohm-shared.h>
 
 /* Regulator IDs */
 enum {
@@ -160,6 +161,7 @@ enum {
 #define BD71828_REG_RTC_YEAR		0x52
 
 #define BD71828_REG_RTC_ALM0_SEC	0x53
+#define BD71828_REG_RTC_ALM_START	BD71828_REG_RTC_ALM0_SEC
 #define BD71828_REG_RTC_ALM0_MINUTE	0x54
 #define BD71828_REG_RTC_ALM0_HOUR	0x55
 #define BD71828_REG_RTC_ALM0_WEEK	0x56
@@ -178,6 +180,7 @@ enum {
 #define BD71828_REG_RTC_ALM1_MASK	0x62
 
 #define BD71828_REG_RTC_ALM2		0x63
+#define BD71828_REG_RTC_START		BD71828_REG_RTC_SEC
 
 /* Charger/Battey */
 #define BD71828_REG_CHG_STATE		0x65
@@ -204,7 +207,6 @@ enum {
 #define BD71828_REG_INT_MASK_TEMP	0xdd
 #define BD71828_REG_INT_MASK_RTC	0xde
 
-
 #define BD71828_REG_INT_MAIN		0xdf
 #define BD71828_REG_INT_BUCK		0xe0
 #define BD71828_REG_INT_DCIN1		0xe1

include/linux/mfd/rohm-shared.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2020 ROHM Semiconductors */
+
+
+#ifndef __LINUX_MFD_ROHM_SHARED_H__
+#define __LINUX_MFD_ROHM_SHARED_H__
+
+/* RTC definitions shared between BD70528 and BD71828 */
+
+#define BD70528_MASK_RTC_SEC		0x7f
+#define BD70528_MASK_RTC_MINUTE		0x7f
+#define BD70528_MASK_RTC_HOUR_24H	0x80
+#define BD70528_MASK_RTC_HOUR_PM	0x20
+#define BD70528_MASK_RTC_HOUR		0x3f
+#define BD70528_MASK_RTC_DAY		0x3f
+#define BD70528_MASK_RTC_WEEK		0x07
+#define BD70528_MASK_RTC_MONTH		0x1f
+#define BD70528_MASK_RTC_YEAR		0xff
+#define BD70528_MASK_ALM_EN		0x7
+
+#endif /* __LINUX_MFD_ROHM_SHARED_H__ */