Hi Crystal, Matthias, On Wed, 2020-07-29 at 09:48 +0200, Matthias Brugger wrote: > > On 29/07/2020 09:39, Crystal Guo wrote: > > Add ti_syscon_reset() to integrate assert and deassert together, > > and change return value of the reset assert and deassert interface > > from regmap_update_bits to regmap_write_bits. > > > > when clear bit is already 1, regmap_update_bits can not write 1 to it again. > > Some IC has the feature that, when set bit is 1, the clear bit change > > to 1 together. It will truly clear bit to 0 by write 1 to the clear bit > > > > Signed-off-by: Crystal Guo <crystal....@mediatek.com> > > --- > > drivers/reset/reset-ti-syscon.c | 13 +++++++++++-- > > 1 file changed, 11 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/reset/reset-ti-syscon.c > > b/drivers/reset/reset-ti-syscon.c > > index a2635c2..5a8ec8f 100644 > > --- a/drivers/reset/reset-ti-syscon.c > > +++ b/drivers/reset/reset-ti-syscon.c > > @@ -89,7 +89,7 @@ static int ti_syscon_reset_assert(struct > > reset_controller_dev *rcdev, > > mask = BIT(control->assert_bit); > > value = (control->flags & ASSERT_SET) ? mask : 0x0; > > > > - return regmap_update_bits(data->regmap, control->assert_offset, mask, > > value); > > + return regmap_write_bits(data->regmap, control->assert_offset, mask, > > value); > > Nack, this will break the driver for the other devices.
I don't think this will break the driver for existing hardware. regmap_write_bits() is the same as regmap_update_bits(), it just forces the write in case the read already happens to return the correct value. Of course it would be good to check that this actually works. > The kernel has to work not just for your SoC but for all devices of all > architectures. You can't just hack something up, that will work on your > specific > SoC. > > Regards, > Matthias > > > } > > > > /** > > @@ -120,7 +120,7 @@ static int ti_syscon_reset_deassert(struct > > reset_controller_dev *rcdev, > > mask = BIT(control->deassert_bit); > > value = (control->flags & DEASSERT_SET) ? mask : 0x0; > > > > - return regmap_update_bits(data->regmap, control->deassert_offset, mask, > > value); > > + return regmap_write_bits(data->regmap, control->deassert_offset, mask, > > value); > > } > > > > /** > > @@ -158,10 +158,19 @@ static int ti_syscon_reset_status(struct > > reset_controller_dev *rcdev, > > !(control->flags & STATUS_SET); > > } > > > > +static int ti_syscon_reset(struct reset_controller_dev *rcdev, > > + unsigned long id) > > +{ > > + ti_syscon_reset_assert(rcdev, id); > > + > > + return ti_syscon_reset_deassert(rcdev, id); > > +} > > + I'm unsure about this one, though. This is an incompatible change. At the very least this would have to be optional depending on compatible. regards Philipp