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: 7947219ab1a2d ("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 --- Changes in v5: - Add error message.

Changes in v4: - Move the registers unlock in the probe instead of a custom regmap write operation.

Changes in v3: - Removed unused variable.

Changes in v2: - Setup a custom regmap_bus only for the TPS65214 instead of checking the chip_id every time reg_write is called. --- drivers/mfd/tps65219.c | 9 +++++++++ include/linux/mfd/tps65219.h | 2 ++ 2 files changed, 11 insertions(+)

diff --git a/drivers/mfd/tps65219.c b/drivers/mfd/tps65219.c index 65a952555218d..7275dcdb7c44f 100644 --- a/drivers/mfd/tps65219.c +++ b/drivers/mfd/tps65219.c @@ -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); diff --git a/include/linux/mfd/tps65219.h b/include/linux/mfd/tps65219.h index 55234e771ba73..3abf937191d0c 100644 --- a/include/linux/mfd/tps65219.h +++ b/include/linux/mfd/tps65219.h @@ -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)