[PATCH] rtc: max77683: avoid regmap bulk write for max77620

[Venkat Reddy Talla]

Adding support to avoid regmap bulk write for the
devices which are not supported register bulk write.
Max77620 RTC device does not support register bulk write
so disabling regmap bulk write for max77620 rtc device
and enabling only for max77683.

Signed-off-by: Venkat Reddy Talla <vreddytalla@xxxxxxxxxx>
---
 drivers/rtc/rtc-max77686.c | 39 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c
index 182fdd0..401ab25 100644
--- a/drivers/rtc/rtc-max77686.c
+++ b/drivers/rtc/rtc-max77686.c
@@ -84,6 +84,7 @@ struct max77686_rtc_driver_data {
 	int			alarm_pending_status_reg;
 	/* RTC IRQ CHIP for regmap */
 	const struct regmap_irq_chip *rtc_irq_chip;
+	bool avoid_rtc_bulk_write;
 };
 
 struct max77686_rtc_info {
@@ -197,6 +198,7 @@ static const struct max77686_rtc_driver_data max77686_drv_data = {
 	.alarm_pending_status_reg = MAX77686_REG_STATUS2,
 	.rtc_i2c_addr = MAX77686_I2C_ADDR_RTC,
 	.rtc_irq_chip = &max77686_rtc_irq_chip,
+	.avoid_rtc_bulk_write = false,
 };
 
 static const struct max77686_rtc_driver_data max77620_drv_data = {
@@ -208,6 +210,7 @@ static const struct max77686_rtc_driver_data max77620_drv_data = {
 	.alarm_pending_status_reg = MAX77686_INVALID_REG,
 	.rtc_i2c_addr = MAX77620_I2C_ADDR_RTC,
 	.rtc_irq_chip = &max77686_rtc_irq_chip,
+	.avoid_rtc_bulk_write = true,
 };
 
 static const unsigned int max77802_map[REG_RTC_END] = {
@@ -259,6 +262,32 @@ static const struct max77686_rtc_driver_data max77802_drv_data = {
 	.rtc_irq_chip = &max77802_rtc_irq_chip,
 };
 
+static inline int _regmap_bulk_write(struct max77686_rtc_info *info,
+		unsigned int reg, void *val, int len)
+{
+	int ret = 0;
+
+	if (!info->drv_data->avoid_rtc_bulk_write) {
+		/* RTC registers support sequential writing */
+		ret = regmap_bulk_write(info->rtc_regmap, reg, val, len);
+	} else {
+		/* Power registers support register-data pair writing */
+		u8 *src = (u8 *)val;
+		int i;
+
+		for (i = 0; i < len; i++) {
+			ret = regmap_write(info->rtc_regmap, reg, *src++);
+			if (ret < 0)
+				break;
+			reg++;
+		}
+	}
+	if (ret < 0)
+		dev_err(info->dev, "%s() failed, e %d\n", __func__, ret);
+
+	return ret;
+}
+
 static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
 				    struct max77686_rtc_info *info)
 {
@@ -383,7 +412,7 @@ static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)
 
 	mutex_lock(&info->lock);
 
-	ret = regmap_bulk_write(info->rtc_regmap,
+	ret = _regmap_bulk_write(info,
 				info->drv_data->map[REG_RTC_SEC],
 				data, ARRAY_SIZE(data));
 	if (ret < 0) {
@@ -506,7 +535,7 @@ static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
 		for (i = 0; i < ARRAY_SIZE(data); i++)
 			data[i] &= ~ALARM_ENABLE_MASK;
 
-		ret = regmap_bulk_write(info->rtc_regmap, map[REG_ALARM1_SEC],
+		ret = _regmap_bulk_write(info, map[REG_ALARM1_SEC],
 					data, ARRAY_SIZE(data));
 	}
 
@@ -558,7 +587,7 @@ static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
 		if (data[RTC_DATE] & 0x1f)
 			data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);
 
-		ret = regmap_bulk_write(info->rtc_regmap, map[REG_ALARM1_SEC],
+		ret = _regmap_bulk_write(info, map[REG_ALARM1_SEC],
 					data, ARRAY_SIZE(data));
 	}
 
@@ -588,7 +617,7 @@ static int max77686_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	if (ret < 0)
 		goto out;
 
-	ret = regmap_bulk_write(info->rtc_regmap,
+	ret = _regmap_bulk_write(info,
 				info->drv_data->map[REG_ALARM1_SEC],
 				data, ARRAY_SIZE(data));
 
@@ -654,7 +683,7 @@ static int max77686_rtc_init_reg(struct max77686_rtc_info *info)
 
 	info->rtc_24hr_mode = 1;
 
-	ret = regmap_bulk_write(info->rtc_regmap,
+	ret = _regmap_bulk_write(info,
 				info->drv_data->map[REG_RTC_CONTROLM],
 				data, ARRAY_SIZE(data));
 	if (ret < 0) {
-- 
2.1.4