From 83cbc83905d756a4da933af63c86ca37d6af64f9 Mon Sep 17 00:00:00 2001
From: Phil Howard <phil@gadgetoid.com>
Date: Fri, 29 Mar 2019 10:53:14 +0000
Subject: [PATCH] rtc: rv3028: Add backup switchover mode support
Signed-off-by: Phil Howard <phil@pimoroni.com>
---
drivers/rtc/rtc-rv3028.c | 45 +++++++++++++++++++++++++++++++++++-----
1 file changed, 40 insertions(+), 5 deletions(-)
--- a/drivers/rtc/rtc-rv3028.c
+++ b/drivers/rtc/rtc-rv3028.c
@@ -860,6 +860,8 @@ static int rv3028_probe(struct i2c_clien
struct rv3028_data *rv3028;
int ret, status;
u32 ohms;
+ u32 bsm;
+ u8 backup, backup_bits, backup_mask;
struct nvmem_config nvmem_cfg = {
.name = "rv3028_nvram",
.word_size = 1,
@@ -926,6 +928,21 @@ static int rv3028_probe(struct i2c_clien
if (ret)
return ret;
+ backup_bits = 0;
+ backup_mask = 0;
+
+ /* setup backup switchover mode */
+ if (!device_property_read_u32(&client->dev,
+ "backup-switchover-mode",
+ &bsm)) {
+ if (bsm <= 3) {
+ backup_bits |= (u8)(bsm << 2);
+ backup_mask |= RV3028_BACKUP_BSM;
+ } else {
+ dev_warn(&client->dev, "invalid backup switchover mode value\n");
+ }
+ }
+
/* setup trickle charger */
if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
&ohms)) {
@@ -936,15 +953,33 @@ static int rv3028_probe(struct i2c_clien
break;
if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
- ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
- RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i);
- if (ret)
- return ret;
+ backup_bits |= RV3028_BACKUP_TCE | i;
+ backup_mask |= RV3028_BACKUP_TCE |
+ RV3028_BACKUP_TCR_MASK;
} else {
- dev_warn(&client->dev, "invalid trickle resistor value\n");
+ dev_warn(&client->dev,
+ "invalid trickle resistor value\n");
}
}
+ if (backup_mask) {
+ ret = rv3028_eeprom_read((void *)rv3028, RV3028_BACKUP,
+ (void *)&backup, 1);
+ /* Write register and EEPROM if needed */
+ if (!ret && (backup & backup_mask) != backup_bits) {
+ backup = (backup & ~backup_mask) | backup_bits;
+ ret = rv3028_update_cfg(rv3028, RV3028_BACKUP,
+ backup_mask, backup_bits);
+ }
+
+ /* In the event of an EEPROM failure, just update the register */
+ if (ret)
+ ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP,
+ backup_mask, backup_bits);
+ if (ret)
+ return ret;
+ }
+
ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
if (ret)
return ret;