mfd: tps65910: Correct power-off programming sequence

Correct power-off programming sequence in order to fix shutting down
devices which are using TPS65910 PMIC.

In accordance to the TPS65910 datasheet, the PMIC's state-machine
transitions into the OFF state only when DEV_OFF bit of DEVCTRL_REG is
set. The ON / SLEEP states also should be cleared, otherwise PMIC won't
get into a proper state on shutdown. Devices like Nexus 7 tablet and Ouya
game console are shutting down properly now.

Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Zack Pearsall <zpearsall@yahoo.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/mfd/tps65910.c b/drivers/mfd/tps65910.c
index ca0b610..6e105cc 100644 (file)
--- a/drivers/mfd/tps65910.c
+++ b/drivers/mfd/tps65910.c
@@ -436,12 +436,18 @@ static void tps65910_power_off(void)
 
        tps65910 = dev_get_drvdata(&tps65910_i2c_client->dev);
 
+       /*
+        * The PWR_OFF bit needs to be set separately, before transitioning
+        * to the OFF state. It enables the "sequential" power-off mode on
+        * TPS65911, it's a NO-OP on TPS65910.
+        */
        if (regmap_set_bits(tps65910->regmap, TPS65910_DEVCTRL,
                            DEVCTRL_PWR_OFF_MASK) < 0)
                return;
 
-       regmap_clear_bits(tps65910->regmap, TPS65910_DEVCTRL,
-                         DEVCTRL_DEV_ON_MASK);
+       regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
+                          DEVCTRL_DEV_OFF_MASK | DEVCTRL_DEV_ON_MASK,
+                          DEVCTRL_DEV_OFF_MASK);
 }
 
 static int tps65910_i2c_probe(struct i2c_client *i2c,