Messages in this thread Patch in this message | | | From | Jonathan Bakker <> | Subject | [PATCH] regulator: wm8994: Add an off-on delay for WM8994 variant | Date | Sun, 27 Mar 2022 15:15:53 -0700 |
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As per Table 130 of the wm8994 datasheet at [1], there is an off-on delay for LDO1 and LDO2. In the wm8958 datasheet [2], I could not find any reference to it. I could not find a wm1811 datasheet to double-check there, but as no one has complained presumably it works without it.
This solves the issue on Samsung Aries boards with a wm8994 where register writes fail when the device is powered off and back-on quickly.
[1] https://statics.cirrus.com/pubs/proDatasheet/WM8994_Rev4.6.pdf [2] https://statics.cirrus.com/pubs/proDatasheet/WM8958_v3.5.pdf
Signed-off-by: Jonathan Bakker <xc-racer2@live.ca> --- drivers/regulator/wm8994-regulator.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/regulator/wm8994-regulator.c b/drivers/regulator/wm8994-regulator.c index cadea0344486..135fdf3f9fdd 100644 --- a/drivers/regulator/wm8994-regulator.c +++ b/drivers/regulator/wm8994-regulator.c @@ -70,7 +70,7 @@ static const struct regulator_ops wm8994_ldo2_ops = { .set_voltage_sel = regulator_set_voltage_sel_regmap, }; -static const struct regulator_desc wm8994_ldo_desc[] = { +static struct regulator_desc wm8994_ldo_desc[] = { { .name = "LDO1", .id = 1, @@ -167,6 +167,10 @@ static int wm8994_ldo_probe(struct platform_device *pdev) ldo->init_data = *pdata->ldo[id].init_data; } + /* WM8994 requires an off-on delay while others do not */ + if (ldo->wm8994->type == WM8994) + wm8994_ldo_desc[id].off_on_delay = 36000; + /* * At this point the GPIO descriptor is handled over to the * regulator core and we need not worry about it on the -- 2.20.1
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