ACK: [J/OEM-5.14] [PATCH] iio: light: cm32181: Add PM support

[Stefan Bader]

On 04.08.22 14:24, Kai-Heng Feng wrote:
> On Thu, Aug 4, 2022 at 8:15 PM Stefan Bader <stefan.bader at canonical.com> wrote:
>>
>> On 15.07.22 03:08, Kai-Heng Feng wrote:
>>> BugLink: https://bugs.launchpad.net/bugs/1981773
>>>
>>> The read on in_illuminance_input keeps at 0 after system sleep.
>>>
>>> So add proper suspend and resume callback to make the sensor keep
>>> working after system sleep.
>>>
>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
>>> Link: https://lore.kernel.org/r/20220707000151.33381-1-kai.heng.feng@canonical.com
>>> Signed-off-by: Jonathan Cameron <Jonathan.Cameron at huawei.com>
>>> (backported from commit 68c1b3dd5c48b2323067f8c1f0649ae2f31ab20b linux-next)
>>> [khfeng: Use #ifdef instead of backporting new PM macros]
>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
>>> ---
>>>    drivers/iio/light/cm32181.c | 24 ++++++++++++++++++++++++
>>>    1 file changed, 24 insertions(+)
>>>
>>> diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
>>> index 97649944f1df6..3d52b8caf29a3 100644
>>> --- a/drivers/iio/light/cm32181.c
>>> +++ b/drivers/iio/light/cm32181.c
>>> @@ -460,6 +460,8 @@ static int cm32181_probe(struct i2c_client *client)
>>>                        return PTR_ERR(client);
>>>        }
>>>
>>> +     i2c_set_clientdata(client, indio_dev);
>>> +
>>>        cm32181 = iio_priv(indio_dev);
>>>        cm32181->client = client;
>>>        cm32181->dev = dev;
>>> @@ -486,6 +488,27 @@ static int cm32181_probe(struct i2c_client *client)
>>>        return 0;
>>>    }
>>>
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int cm32181_suspend(struct device *dev)
>>> +{
>>> +     struct i2c_client *client = to_i2c_client(dev);
>>> +
>>> +     return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
>>> +                                      CM32181_CMD_ALS_DISABLE);
>>> +}
>>> +
>>> +static int cm32181_resume(struct device *dev)
>>> +{
>>> +     struct i2c_client *client = to_i2c_client(dev);
>>> +     struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
>>> +
>>> +     return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
>>> +                                      cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
>>> +}
>>> +#endif
>>> +
>>> +SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume);
>>
>> Hm, does this not break when CONFIG_PM is not set? I think this needs an #else
>> case which defines empty sudpend/resume handlers, no?
> 
> Commit 1a3c7bb08826 ("PM: core: Add new *_PM_OPS macros, deprecate old
> ones"), which is included in v5.17, adds pm_sleep_ptr() and other
> helpers to deprecate the usage #ifdef CONFIG_PM. So those #ifdef are
> no longer needed for newer kernels.
> 

Ah, so before above commit SIMPLE_DEV_PM_OPS is using SET_SYSTEM_SLEEP_PM_OPS 
which does nothing if PM_SLEEP is undefined. But it still will define a function 
table with NULL pointers that can be used in the device table.

Acked-by: Stefan Bader <stefan.bader at canonical.com>

> The version for Jammy and OEM-5.14 still have #ifdef guard so they
> won't break when CONFIG_PM is unset.
> 
> Kai-Heng
> 
>>
>> -Stefan
>>
>>> +
>>>    static const struct of_device_id cm32181_of_match[] = {
>>>        { .compatible = "capella,cm3218" },
>>>        { .compatible = "capella,cm32181" },
>>> @@ -506,6 +529,7 @@ static struct i2c_driver cm32181_driver = {
>>>                .name   = "cm32181",
>>>                .acpi_match_table = ACPI_PTR(cm32181_acpi_match),
>>>                .of_match_table = cm32181_of_match,
>>> +             .pm = &cm32181_pm_ops,
>>>        },
>>>        .probe_new      = cm32181_probe,
>>>    };
>>

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