Re: [v2,5/6] reset-controller: ti: Introduce force-update method

Suman Anna
2020-09-02T23:05:31Z

Hi Crystal,

On 8/10/20 1:57 AM, Crystal Guo wrote:
> On Tue, 2020-08-04 at 15:03 +0800, Philipp Zabel wrote:
>> Hi Crystal,
>>
>> On Mon, 2020-08-03 at 14:15 +0800, Crystal Guo wrote:
>>> Introduce force-update method for assert and deassert interface,
>>> which force the write operation in case the read already happens
>>> to return the correct value.
>>>
>>> Signed-off-by: Crystal Guo <crystal.guo@mediatek.com>
>>
>> Added Suman and Andrew for confirmation: I think writing unconditionally
>> can't break any existing user. Just changing to regmap_write_bits()
>> instead of adding the update-force property as in v1 should be fine.
>>
>> regards
>> Philipp
>>
> Hi Suman, Andrew,
>
> Can you help to give some suggestions about this change.
> Is this can be changed to write unconditionally, or should I add a
> update-force property to force the write operation.

Sorry for the delay on this one, I have tested your latest v4, and everything is
functional on the TI SoCs. We do use the same register for asserting and
deasserting and is not self-clearing, and have additional non-reset related bits
in the register, so this change doesn't impact us. I have some minor
comments/questions that I will post on your v4.

Removing Andrew to not have the emails bounce.

regards
Suman

>
> Best regards
> Crystal.
>
>>> ---
>>> drivers/reset/reset-ti-syscon.c | 15 +++++++++++++--
>>> 1 file changed, 13 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/reset/reset-ti-syscon.c b/drivers/reset/reset-ti-syscon.c
>>> index 1c74bcb9a6c3..f4baf78afd14 100644
>>> --- a/drivers/reset/reset-ti-syscon.c
>>> +++ b/drivers/reset/reset-ti-syscon.c
>>> @@ -57,6 +57,7 @@ struct ti_syscon_reset_data {
>>> struct ti_syscon_reset_control *controls;
>>> unsigned int nr_controls;
>>> bool assert_deassert_together;
>>> + bool update_force;
>>> };
>>>
>>> #define to_ti_syscon_reset_data(rcdev) \
>>> @@ -90,7 +91,10 @@ 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);
>>> + if (data->update_force)
>>> + return regmap_write_bits(data->regmap, control->assert_offset, mask, value);
>>> + else
>>> + return regmap_update_bits(data->regmap, control->assert_offset, mask, value);
>>> }
>>>
>>> /**
>>> @@ -121,7 +125,10 @@ 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);
>>> + if (data->update_force)
>>> + return regmap_write_bits(data->regmap, control->deassert_offset, mask, value);
>>> + else
>>> + return regmap_update_bits(data->regmap, control->deassert_offset, mask, value);
>>> }
>>>
>>> /**
>>> @@ -223,6 +230,10 @@ static int ti_syscon_reset_probe(struct platform_device *pdev)
>>> data->assert_deassert_together = true;
>>> else
>>> data->assert_deassert_together = false;
>>> + if (of_property_read_bool(np, "update-force"))
>>> + data->update_force = true;
>>> + else
>>> + data->update_force = false;
>>>
>>> data->rcdev.ops = &ti_syscon_reset_ops;
>>> data->rcdev.owner = THIS_MODULE;
>>> --
>>> 2.18.0
>