From 3c87b351809f220294aec3c0df7b078ff5c5b15b Mon Sep 17 00:00:00 2001 From: Andrej Picej Date: Fri, 23 Jun 2023 10:15:33 +0200 Subject: rtc: rv3028: Add support for "aux-voltage-chargeable" property Property "trickle-resistor-ohms" allows us to set trickle charger resistor. However there is no possibility to disable it afterwards. Add support for "aux-voltage-chargeable" property which can be used to enable/disable the trickle charger circuit explicitly. The default behavior of the code is kept as it is! Additionally, lets make sure we only update internal EEPROM in case of a change. This prevents wear due to excessive EEPROM writes on each probe. Signed-off-by: Andrej Picej Link: https://lore.kernel.org/r/20230623081533.76334-1-andrej.picej@norik.com Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-rv3028.c | 80 ++++++++++++++++++++++++++++++++++++------------ 1 file changed, 61 insertions(+), 19 deletions(-) diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c index 076e56f4e01a..e039b472eaa6 100644 --- a/drivers/rtc/rtc-rv3028.c +++ b/drivers/rtc/rtc-rv3028.c @@ -855,11 +855,68 @@ static const struct regmap_config regmap_config = { .max_register = 0x37, }; +static u8 rv3028_set_trickle_charger(struct rv3028_data *rv3028, + struct i2c_client *client) +{ + int ret, val_old, val; + u32 ohms, chargeable; + + ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old); + if (ret < 0) + return ret; + + /* mask out only trickle charger bits */ + val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK); + val = val_old; + + /* setup trickle charger */ + if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms", + &ohms)) { + int i; + + for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++) + if (ohms == rv3028_trickle_resistors[i]) + break; + + if (i < ARRAY_SIZE(rv3028_trickle_resistors)) { + /* enable trickle charger and its resistor */ + val = RV3028_BACKUP_TCE | i; + } else { + dev_warn(&client->dev, "invalid trickle resistor value\n"); + } + } + + if (!device_property_read_u32(&client->dev, "aux-voltage-chargeable", + &chargeable)) { + switch (chargeable) { + case 0: + val &= ~RV3028_BACKUP_TCE; + break; + case 1: + val |= RV3028_BACKUP_TCE; + break; + default: + dev_warn(&client->dev, + "unsupported aux-voltage-chargeable value\n"); + break; + } + } + + /* only update EEPROM if changes are necessary */ + if (val_old != val) { + ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE | + RV3028_BACKUP_TCR_MASK, val); + if (ret) + return ret; + } + + return ret; +} + static int rv3028_probe(struct i2c_client *client) { struct rv3028_data *rv3028; int ret, status; - u32 ohms; struct nvmem_config nvmem_cfg = { .name = "rv3028_nvram", .word_size = 1, @@ -937,24 +994,9 @@ static int rv3028_probe(struct i2c_client *client) if (ret) return ret; - /* setup trickle charger */ - if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms", - &ohms)) { - int i; - - for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++) - if (ohms == rv3028_trickle_resistors[i]) - 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; - } else { - dev_warn(&client->dev, "invalid trickle resistor value\n"); - } - } + ret = rv3028_set_trickle_charger(rv3028, client); + if (ret) + return ret; ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group); if (ret) -- cgit v1.2.3