Commit 3c87b351 authored by Andrej Picej's avatar Andrej Picej Committed by Alexandre Belloni
Browse files

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: default avatarAndrej Picej <andrej.picej@norik.com>
Link: https://lore.kernel.org/r/20230623081533.76334-1-andrej.picej@norik.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 766c3f8a

drivers/rtc/rtc-rv3028.c

+61 −19
Original line number Diff line number Diff line
@@ -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);

	ret = rv3028_set_trickle_charger(rv3028, client);

	if (ret)

		return ret;

		} else {

			dev_warn(&client->dev, "invalid trickle resistor value\n");

		}

	}



	ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);

	if (ret)