On 9/8/20 9:57 PM, Crystal Guo wrote:
> On Thu, 2020-09-03 at 07:40 +0800, Suman Anna wrote:
>> Hi Crystal,
>>
>> On 8/16/20 10:03 PM, Crystal Guo wrote:
>>> Introduce ti_syscon_reset() to integrate assert and deassert together.
>>> If some modules need do serialized assert and deassert operations
>>> to reset itself, reset_control_reset can be called for convenience.
>>
>> There are multiple changes in this same patch. I think you should split this
>> functionality away from the change for the regmap_update_bits() to
>> regmap_write_bits(), similar to what you have done in your v2 Patch 4.
>>
>
> Thanks for your suggestion.
> I will split this patch in the next version.
>
>>>
>>> Such as reset-qcom-aoss.c, it integrates assert and deassert together
>>> by 'reset' method. MTK Socs also need this method to perform reset.
>>>
>>> Signed-off-by: Crystal Guo <crystal.guo@xxxxxxxxxxxx>
>>> ---
>>> drivers/reset/reset-ti-syscon.c | 26 ++++++++++++++++++++++++--
>>> 1 file changed, 24 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/reset/reset-ti-syscon.c b/drivers/reset/reset-ti-syscon.c
>>> index a2635c21db7f..08289342f9af 100644
>>> --- a/drivers/reset/reset-ti-syscon.c
>>> +++ b/drivers/reset/reset-ti-syscon.c
>>> @@ -15,6 +15,7 @@
>>> * GNU General Public License for more details.
>>> */
>>>
>>> +#include <linux/delay.h>
>>> #include <linux/mfd/syscon.h>
>>> #include <linux/module.h>
>>> #include <linux/of.h>
>>> @@ -56,6 +57,7 @@ struct ti_syscon_reset_data {
>>> struct regmap *regmap;
>>> struct ti_syscon_reset_control *controls;
>>> unsigned int nr_controls;
>>> + unsigned int reset_duration_us;
>>> };
>>>
>>> #define to_ti_syscon_reset_data(rcdev) \
>>> @@ -89,7 +91,7 @@ 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);
>>> }
>>>
>>> /**
>>> @@ -120,7 +122,7 @@ 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);
>>> }
>>>
>>> /**
>>> @@ -158,9 +160,26 @@ 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)
>>> +{
>>> + struct ti_syscon_reset_data *data = to_ti_syscon_reset_data(rcdev);
>>> + int ret;
>>> +
>>> + ret = ti_syscon_reset_assert(rcdev, id);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + if (data->reset_duration_us)
>>> + usleep_range(data->reset_duration_us, data->reset_duration_us * 2);
>>> +
>>> + return ti_syscon_reset_deassert(rcdev, id);
>>
>> I echo Philipp's comments [1] from your original v1 series about this. We don't
>> need a property to distinguish this, but you could add a flag using match data
>> and Mediatek compatible, and use that within this function, or optionally set
>> this ops based on compatible (whatever is preferred by Philipp).
>>
>> regards
>> Suman
>>
>> [1] https://patchwork.kernel.org/comment/23519193/
>>
> Hi Suman, Philipp
>
> Which method would you recommend more?
> 1. like v2 patch, but assign the flag "data->assert_deassert_together"
> directly (maybe rename "assert_deassert_together" to
> "reset_op_available")
>
> 2. use Mediatek compatible to decide the reset handler available or not.
I would go with this option. Anyway, I think you might have to add the reset SoC
data as well, based on Rob's comment on the binding.
regards
Suman
>
> Thanks
> Crystal
>
>>> +}
>>> +
>>> static const struct reset_control_ops ti_syscon_reset_ops = {
>>> .assert = ti_syscon_reset_assert,
>>> .deassert = ti_syscon_reset_deassert,
>>> + .reset = ti_syscon_reset,
>>> .status = ti_syscon_reset_status,
>>> };
>>>
>>> @@ -204,6 +223,9 @@ static int ti_syscon_reset_probe(struct platform_device *pdev)
>>> controls[i].flags = be32_to_cpup(list++);
>>> }
>>>
>>> + of_property_read_u32(pdev->dev.of_node, "reset-duration-us",
>>> + &data->reset_duration_us);
>>> +
>>> data->rcdev.ops = &ti_syscon_reset_ops;
>>> data->rcdev.owner = THIS_MODULE;
>>> data->rcdev.of_node = np;
>>>
>>
>
