On 10/4/20 8:07 PM, Chu Lin wrote:
> On Sun, Oct 4, 2020 at 8:43 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>>
>> On Sun, Oct 04, 2020 at 03:14:45AM +0000, Chu Lin wrote:
>>> Problem:
>>> We use voltage dividers so that the voltage presented at the voltage
>>> sense pins is confusing. We might need to convert these readings to more
>>> meaningful readings given the voltage divider.
>>>
>>> Solution:
>>> Read the voltage divider resistance from dts and convert the voltage
>>> reading to a more meaningful reading.
>>>
>>> Testing:
>>> max20730 with voltage divider
>>>
>>> Signed-off-by: Chu Lin <linchuyuan@xxxxxxxxxx>
>>> ---
>>> ChangeLog v1 -> v2
>>> hwmon: pmbus: max20730:
>>> - Don't do anything to the ret if an error is returned from pmbus_read_word
>>> - avoid overflow when doing multiplication
>>>
>>> ChangeLog v2 -> v3
>>> dt-bindings: hwmon: max20730:
>>> - Provide the binding documentation in yaml format
>>> hwmon: pmbus: max20730:
>>> - No change
>>>
>>> ChangeLog v3 -> v4
>>> dt-bindings: hwmon: max20730:
>>> - Fix highefficiency to high efficiency in description
>>> - Fix presents to present in vout-voltage-divider
>>> - Add additionalProperties: false
>>> hwmon: pmbus: max20730:
>>> - No change
>>
>> You claim that there have been no changes since v2 of this patch,
>> yet you dropped my Reviewed-by: tag. Any reason ?
>>
>> Guenter
> Sorry for the confusion. I thought I can't tag the patch with the Review-by tag.
> Just to make sure I do correctly next time, once you tagged a certain
> patch in the batch
> If there is no change from version to version for this patch, I should
> carry the tags when
> submitting new revisions. Also, please let me know what is the best
> way to fix this revision?
> Should I submit a new V5 with the tag attached?
>
Actually, if you did not make changes to a patch, you are _expected_
to carry tags forward. In many cases, submitters will even send a new
version of a patch with all new tags included (and no other changes).
This helps reviewers to keep track on what has been reviewed, acked,
or tested in a series. Dropping a tag means that you changed
a patch so substantially that the tag no longer applies (for example,
fixing a spelling error or some formatting does not normally warrant
dropping a tag). If you do drop a tag, you should explain the reason
in the change log.
That is, of course, a honor system that must not be abused
(unfortunately I have seen that abuse happen a couple of times
recently, but that is another story).
No need to re-send in this case - I'll just send another tag
to remind myself that I reviewed this patch.
Guenter
> Sincerely,
> Chu
>
>>
>>>
>>> drivers/hwmon/pmbus/max20730.c | 18 ++++++++++++++++++
>>> 1 file changed, 18 insertions(+)
>>>
>>> diff --git a/drivers/hwmon/pmbus/max20730.c b/drivers/hwmon/pmbus/max20730.c
>>> index a151a2b588a5..fbf2f1e6c969 100644
>>> --- a/drivers/hwmon/pmbus/max20730.c
>>> +++ b/drivers/hwmon/pmbus/max20730.c
>>> @@ -31,6 +31,7 @@ struct max20730_data {
>>> struct pmbus_driver_info info;
>>> struct mutex lock; /* Used to protect against parallel writes */
>>> u16 mfr_devset1;
>>> + u32 vout_voltage_divider[2];
>>> };
>>>
>>> #define to_max20730_data(x) container_of(x, struct max20730_data, info)
>>> @@ -114,6 +115,14 @@ static int max20730_read_word_data(struct i2c_client *client, int page,
>>> max_c = max_current[data->id][(data->mfr_devset1 >> 5) & 0x3];
>>> ret = val_to_direct(max_c, PSC_CURRENT_OUT, info);
>>> break;
>>> + case PMBUS_READ_VOUT:
>>> + ret = pmbus_read_word_data(client, page, phase, reg);
>>> + if (ret > 0 && data->vout_voltage_divider[0] && data->vout_voltage_divider[1]) {
>>> + u64 temp = DIV_ROUND_CLOSEST_ULL((u64)ret * data->vout_voltage_divider[1],
>>> + data->vout_voltage_divider[0]);
>>> + ret = clamp_val(temp, 0, 0xffff);
>>> + }
>>> + break;
>>> default:
>>> ret = -ENODATA;
>>> break;
>>> @@ -364,6 +373,15 @@ static int max20730_probe(struct i2c_client *client,
>>> data->id = chip_id;
>>> mutex_init(&data->lock);
>>> memcpy(&data->info, &max20730_info[chip_id], sizeof(data->info));
>>> + if (of_property_read_u32_array(client->dev.of_node, "vout-voltage-divider",
>>> + data->vout_voltage_divider,
>>> + ARRAY_SIZE(data->vout_voltage_divider)) != 0)
>>> + memset(data->vout_voltage_divider, 0, sizeof(data->vout_voltage_divider));
>>> + if (data->vout_voltage_divider[1] < data->vout_voltage_divider[0]) {
>>> + dev_err(dev,
>>> + "The total resistance of voltage divider is less than output resistance\n");
>>> + return -ENODEV;
>>> + }
>>>
>>> ret = i2c_smbus_read_word_data(client, MAX20730_MFR_DEVSET1);
>>> if (ret < 0)
>>> --
>>> 2.28.0.806.g8561365e88-goog
>>>
