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mfd: tps65219: Implement LOCK register handling for TPS65214

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The TPS65214 PMIC variant has a LOCK_REG register that prevents writes to
nearly all registers when locked. Unlock the registers at probe time and
leave them unlocked permanently.

This approach is justified because:
- Register locking is very uncommon in typical system operation
- No code path is expected to lock the registers during runtime
- Adding a custom regmap write function would add overhead to every
  register write, including voltage changes triggered by CPU OPP
  transitions from the cpufreq governor which could happen quite
  frequently

Cc: stable@vger.kernel.org
Fixes: 7947219ab1 ("mfd: tps65219: Add support for TI TPS65214 PMIC")
Reviewed-by: Andrew Davis <afd@ti.com>
Signed-off-by: Kory Maincent (TI.com) <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20251218-fix_tps65219-v5-1-8bb511417f3a@bootlin.com
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Kory Maincent (TI.com) 2025-12-18 16:06:28 +01:00 • committed by Lee Jones
parent 05995af05b
commit d3fcf276b5
2 changed files with 11 additions and 0 deletions
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9
drivers/mfd/tps65219.c
View file

@ -498,6 +498,15 @@ static int tps65219_probe(struct i2c_client *client)
return ret;
}
if (chip_id == TPS65214) {
ret = i2c_smbus_write_byte_data(client, TPS65214_REG_LOCK,
TPS65214_LOCK_ACCESS_CMD);
if (ret) {
dev_err(tps->dev, "Failed to unlock registers %d\n", ret);
return ret;
}
}
ret = devm_regmap_add_irq_chip(tps->dev, tps->regmap, client->irq,
IRQF_ONESHOT, 0, pmic->irq_chip,
&tps->irq_data);

2
include/linux/mfd/tps65219.h
View file

@ -149,6 +149,8 @@ enum pmic_id {
#define TPS65215_ENABLE_LDO2_EN_MASK BIT(5)
#define TPS65214_ENABLE_LDO1_EN_MASK BIT(5)
#define TPS65219_ENABLE_LDO4_EN_MASK BIT(6)
/* Register Unlock */
#define TPS65214_LOCK_ACCESS_CMD 0x5a
/* power ON-OFF sequence slot */
#define TPS65219_BUCKS_LDOS_SEQUENCE_OFF_SLOT_MASK GENMASK(3, 0)
#define TPS65219_BUCKS_LDOS_SEQUENCE_ON_SLOT_MASK GENMASK(7, 4)