Hi Lee,
On 14/03/17 14:59, Lee Jones wrote:
> On Tue, 14 Feb 2017, Enric Balletbo i Serra wrote:
>
>> From: Stephen Barber <smbar...@chromium.org>
>>
>> If the EC supports RTC host commands, expose an RTC device.
>>
>> Signed-off-by: Stephen Barber <smbar...@chromium.org>
>> Signed-off-by: Enric Balletbo i Serra <enric.balle...@collabora.com>
>> Acked-by: Benson Leung <ble...@chromium.org>
>> ---
>> Changes since v2:
>> - Acked by Benson Leung
>> Changes since v1:
>> - none
>>
>> drivers/platform/chrome/cros_ec_dev.c | 22 ++++++++++++++++++++++
>> 1 file changed, 22 insertions(+)
>>
>> diff --git a/drivers/platform/chrome/cros_ec_dev.c
>> b/drivers/platform/chrome/cros_ec_dev.c
>> index 47268ec..ebe029d 100644
>> --- a/drivers/platform/chrome/cros_ec_dev.c
>> +++ b/drivers/platform/chrome/cros_ec_dev.c
>> @@ -383,6 +383,24 @@ static void cros_ec_sensors_register(struct cros_ec_dev
>> *ec)
>> kfree(msg);
>> }
>>
>> +static const struct mfd_cell cros_ec_rtc_devs[] = {
>> + {
>> + .name = "cros-ec-rtc",
>> + .id = -1,
>> + },
>> +};
>> +
>> +static void cros_ec_rtc_register(struct cros_ec_dev *ec)
>> +{
>> + int ret;
>> +
>> + ret = mfd_add_devices(ec->dev, 0, cros_ec_rtc_devs,
>> + ARRAY_SIZE(cros_ec_rtc_devs),
>> + NULL, 0, NULL);
>> + if (ret)
>> + dev_err(ec->dev, "failed to add cros-ec-rtc device: %d\n", ret);
>> +}
>
> Holey poop! Why are you using the MFD API outside of MFD?
>
> Why can't you register this from the MFD driver?
>
Actually the MFD doesn't know how to check if this feature is available or not,
instead is the platform driver cros_ec_dev who knows how to check this and if it
exists adds the rtc device.
if (cros_ec_check_features(ec, EC_FEATURE_RTC))
cros_ec_rtc_register(ec); /* add the mfd device */
Same approach was used in the same file for the Sensors Hub (already upstream).
See:
drivers/platform/chrome/cros_ec_dev.c:462
drivers/platform/chrome/cros_ec_dev.c:372
I didn't know that the MFD API was restricted outside MFD. In such case what I
need to do is let know the MFD driver about the cros_ec_check_features
(implemented in platform driver cros_ec_dev), this doesn't seems good to me but
I might be wrong. So please, let me know which option do you prefer and if it's
the case we will need to change I'll try to do it.
Note that I think that a similar use case is used in
drivers/iio/common/ssp_sensors/ssp_dev.c:535, where the iio driver registers the
sensors to the mfd.
Thanks,
Enric
>> static int ec_device_probe(struct platform_device *pdev)
>> {
>> int retval = -ENOMEM;
>> @@ -441,6 +459,10 @@ static int ec_device_probe(struct platform_device *pdev)
>> if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
>> cros_ec_sensors_register(ec);
>>
>> + /* check whether this EC instance has RTC host command support */
>> + if (cros_ec_check_features(ec, EC_FEATURE_RTC))
>> + cros_ec_rtc_register(ec);
>> +
>> return 0;
>>
>> dev_reg_failed:
>
