On Wed, 2020-07-29 at 16:02 +0800, Philipp Zabel wrote: > 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.guo@xxxxxxxxxxxx> > > > --- > > > 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. Yes, regmap_write_bits() is the same as regmap_update_bits(), it would not affect existed users. Or should I use a property to separate regmap_write_bits() and regmap_update_bits() ? > > > 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 > > This TI driver was intend to be a generic reset controller (https://lore.kernel.org/patchwork/cover/683585/), so this patch may not just work on a specific SoC. Thanks, Crystal > > > } > > > > > > /** > > > @@ -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 I will add a property to make this change be optional, thanks for you advice. Thanks, Crystal
