Hi Jacopo,
On 12/12/2018 08:21, jacopo mondi wrote:
> Hi Kieran,
>
> On Tue, Dec 11, 2018 at 11:07:09PM +0000, Kieran Bingham wrote:
>> Hi Jacopo,
>>
>> Thank you for the patch,
>>
>> On 11/12/2018 15:16, Jacopo Mondi wrote:
>>> The ADV748x chip supports routing AFE output to either TXA or TXB.
>>> In order to support run-time configuration of video stream path, create an
>>> additional (not enabled) "AFE:8->TXA:0" link, and remove the IMMUTABLE flag
>>> from existing ones.
>>>
>>> Signed-off-by: Jacopo Mondi <jacopo+rene...@jmondi.org>
>>> ---
>>> drivers/media/i2c/adv748x/adv748x-csi2.c | 48
>>> ++++++++++++++++++++------------
>>> 1 file changed, 30 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c
>>> b/drivers/media/i2c/adv748x/adv748x-csi2.c
>>> index 6ce21542ed48..4d1aefc2c8d0 100644
>>> --- a/drivers/media/i2c/adv748x/adv748x-csi2.c
>>> +++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
>>> @@ -27,6 +27,7 @@ static int adv748x_csi2_set_virtual_channel(struct
>>> adv748x_csi2 *tx,
>>> * @v4l2_dev: Video registration device
>>> * @src: Source subdevice to establish link
>>> * @src_pad: Pad number of source to link to this @tx
>>> + * @flags: Flags for the newly created link
>>> *
>>> * Ensure that the subdevice is registered against the v4l2_device, and
>>> link the
>>> * source pad to the sink pad of the CSI2 bus entity.
>>> @@ -34,17 +35,11 @@ static int adv748x_csi2_set_virtual_channel(struct
>>> adv748x_csi2 *tx,
>>> static int adv748x_csi2_register_link(struct adv748x_csi2 *tx,
>>> struct v4l2_device *v4l2_dev,
>>> struct v4l2_subdev *src,
>>> - unsigned int src_pad)
>>> + unsigned int src_pad,
>>> + unsigned int flags)
>>> {
>>> - int enabled = MEDIA_LNK_FL_ENABLED;
>>> int ret;
>>>
>>> - /*
>>> - * Dynamic linking of the AFE is not supported.
>>> - * Register the links as immutable.
>>> - */
>>> - enabled |= MEDIA_LNK_FL_IMMUTABLE;
>>> -
>>
>> Yup - that part certainly needs to go ...
>>
>>> if (!src->v4l2_dev) {
>>> ret = v4l2_device_register_subdev(v4l2_dev, src);
>>> if (ret)
>>> @@ -53,7 +48,7 @@ static int adv748x_csi2_register_link(struct adv748x_csi2
>>> *tx,
>>>
>>> return media_create_pad_link(&src->entity, src_pad,
>>> &tx->sd.entity, ADV748X_CSI2_SINK,
>>> - enabled);
>>> + flags);
>>> }
>>>
>>> /*
>>> -----------------------------------------------------------------------------
>>> @@ -68,24 +63,41 @@ static int adv748x_csi2_registered(struct v4l2_subdev
>>> *sd)
>>> {
>>> struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
>>> struct adv748x_state *state = tx->state;
>>> + int ret;
>>>
>>> adv_dbg(state, "Registered %s (%s)", is_txa(tx) ? "TXA":"TXB",
>>> sd->name);
>>>
>>> /*
>>> - * The adv748x hardware allows the AFE to route through the TXA, however
>>> - * this is not currently supported in this driver.
>>> + * Link TXA to HDMI and AFE, and TXB to AFE only as TXB cannot output
>>> + * HDMI.
>>> *
>>> - * Link HDMI->TXA, and AFE->TXB directly.
>>> + * The HDMI->TXA link is enabled by default, as the AFE->TXB is.
>>> */
>>> - if (is_txa(tx) && is_hdmi_enabled(state))
>>> - return adv748x_csi2_register_link(tx, sd->v4l2_dev,
>>> - &state->hdmi.sd,
>>> - ADV748X_HDMI_SOURCE);
>>> - if (!is_txa(tx) && is_afe_enabled(state))
>>> + if (is_txa(tx)) {
>>> + if (is_hdmi_enabled(state)) {
>>> + ret = adv748x_csi2_register_link(tx, sd->v4l2_dev,
>>> + &state->hdmi.sd,
>>> + ADV748X_HDMI_SOURCE,
>>> + MEDIA_LNK_FL_ENABLED);
>>> + if (ret)
>>> + return ret;
>>> + }
>>> +
>>> + if (is_afe_enabled(state)) {
>>> + ret = adv748x_csi2_register_link(tx, sd->v4l2_dev,
>>> + &state->afe.sd,
>>> + ADV748X_AFE_SOURCE,
>>> + 0);
>>> + if (ret)
>>> + return ret;
>>> + }
>>
>>
>>> + } else if (is_afe_enabled(state))
>>
>> I believe when adding braces to one side of an if statement, we are
>> supposed to add to the else clauses too ?
>
> Correct
>
>>
>>> return adv748x_csi2_register_link(tx, sd->v4l2_dev,
>>> &state->afe.sd,
>>> - ADV748X_AFE_SOURCE);
>>> + ADV748X_AFE_SOURCE,
>>> + MEDIA_LNK_FL_ENABLED);
>>
>> Won't this enable the AFE link for both TXA and TXB ?
>> Which one will win? Just the last one ? the first one ?
>> Does it error?
>>
>> (It might not be a problem ... I can't recall what the behaviour is)
>>
>>
>
> The AFE->TXA link is created as not enabled (see the 0 as last
> argument in the adv748x_csi2_register_link() call above here, in the
> 'is_txa(tx)' case
Ugh - of course it is ... I was clearly way too tired last night. Oops :D
>
>>> +
>>
>> There are a lot of nested if's above, and I think we can simplify
>> greatly if we move the logic for the flags inside
>> adv748x_csi2_register_link(), and adjust the checks on is_xxx_enabled()
>>
>> What do you think about the following pseudo code?:
>>
>>
>> int adv748x_csi2_register_link(struct adv748x_csi2 *tx,
>> struct v4l2_device *v4l2_dev,
>> struct v4l2_subdev *src,
>> unsigned int src_pad,
>> bool enable)
>> {
>>
>> int flags = 0;
>> int ret;
>>
>> if (!src->v4l2_dev) {
>> ret = v4l2_device_register_subdev(v4l2_dev, src)
>> if (ret) return ret;
>> }
>>
>> if (enable)
>> flags = MEDIA_LNK_FL_ENABLED;
>>
>> return media_create_pad_link(&src->entity, src_pad,
>> &tx->sd.entity, ADV748X_CSI2_SINK,
>> flags);
>> }
>>
>> int adv748x_csi2_registered(struct v4l2_subdev *sd)
>> {
>> int ret;
>>
>> if (is_afe_enabled(state) {
>> ret = adv748x_csi2_register_link(tx, sd->v4l2_dev, &state->afe.sd,
>> ADV748X_AFE_SOURCE, !is_txa(tx));
>> if (ret)
>> return ret;
>> }
>>
>> /* TX-B only supports AFE */
>> if (!is_txa(tx) || !(is_hdmi_enabled(state))
>> return 0;
>>
>> return adv748x_csi2_register_link(tx, sd->v4l2_dev, &state->hdmi.sd,
>> ADV748X_HDMI_SOURCE, true);
>> }
>>
>>
>> The above will for TXA:
>> register_link(..., AFE_SOURCE, enable = false );
>> register_link(..., HDMI_SOURCE, enable = true );
>>
>> then TXB:
>> register_link(..., AFE_SOURCE, enable = true );
>>
>> Does that meet our needs?
>>
>
> Yes it does, and it looks better. Thanks!
Great - something useful came out of my non-sleeping sleepiness :)
>>> return 0;
>>> }
>>>
>>> --
>>> 2.7.4
>>>
>>
>> --
>> Regards
>> --
>> Kieran
--
Regards
--
Kieran
