From: Jacopo Mondi <jacopo@jmondi.org>
To: Kieran Bingham <kieran.bingham@ideasonboard.com>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>,
laurent.pinchart@ideasonboard.com,
niklas.soderlund+renesas@ragnatech.se,
linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH v2 6/6] media: adv748x: Implement TX link_setup callback
Date: Thu, 10 Jan 2019 14:40:15 +0100 [thread overview]
Message-ID: <20190110134015.ssd24hnl7fbw4ct7@uno.localdomain> (raw)
In-Reply-To: <9f156850-14b6-3ca2-47c1-e03e1bc2c0f8@ideasonboard.com>
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Hi Kieran,
On Mon, Jan 07, 2019 at 12:36:28PM +0000, Kieran Bingham wrote:
> Hi Jacopo,
>
> On 06/01/2019 15:54, Jacopo Mondi wrote:
> > When the adv748x driver is informed about a link being created from HDMI or
> > AFE to a CSI-2 TX output, the 'link_setup()' callback is invoked. Make
> > sure to implement proper routing management at link setup time, to route
> > the selected video stream to the desired TX output.
>
> Overall this looks like the right approach - but I feel like the
> handling of the io10 register might need some consideration, because
> it's value depends on the condition of both CSI2 transmitters, not just
> the currently parsed link.
>
> I had a go at some pseudo - uncompiled/untested code inline as a suggestion.
>
> If you think it's better - feel free to rework it in ... or not as you
> see fit.
>
> Regards
>
> Kieran
>
>
>
>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > ---
> > drivers/media/i2c/adv748x/adv748x-core.c | 57 +++++++++++++++++++++++-
> > drivers/media/i2c/adv748x/adv748x.h | 2 +
> > 2 files changed, 58 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
> > index 200e00f93546..a586bf393558 100644
> > --- a/drivers/media/i2c/adv748x/adv748x-core.c
> > +++ b/drivers/media/i2c/adv748x/adv748x-core.c
> > @@ -335,6 +335,60 @@ int adv748x_tx_power(struct adv748x_csi2 *tx, bool on)
> > /* -----------------------------------------------------------------------------
> > * Media Operations
> > */
> > +static int adv748x_link_setup(struct media_entity *entity,
> > + const struct media_pad *local,
> > + const struct media_pad *remote, u32 flags)
> > +{
> > + struct v4l2_subdev *rsd = media_entity_to_v4l2_subdev(remote->entity);
> > + struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);
> > + struct adv748x_state *state = v4l2_get_subdevdata(sd);
> > + struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
> > + bool enable = flags & MEDIA_LNK_FL_ENABLED;
> > + u8 io10;
> > +
> > + /* Refuse to enable multiple links to the same TX at the same time. */
> > + if (enable && tx->src)
> > + return -EINVAL;
> > +
> > + /* Set or clear the source (HDMI or AFE) and the current TX. */
> > + if (rsd == &state->afe.sd)
> > + state->afe.tx = enable ? tx : NULL;
> > + else
> > + state->hdmi.tx = enable ? tx : NULL;
> > +
> > + tx->src = enable ? rsd : NULL;
> > +
> > + if (!enable)
> > + return 0;
>
> Don't we potentially want to take any action on disable to power down
> links below ?
>
> > +
> > + /* Change video stream routing, according to the newly enabled link. */
> > + io10 = io_read(state, ADV748X_IO_10);
> > + if (rsd == &state->afe.sd) {
> > + /*
> > + * Set AFE->TXA routing and power off TXB if AFE goes to TXA.
> > + * if AFE goes to TXB, we need both TXA and TXB powered on.
> > + */
> > + io10 &= ~ADV748X_IO_10_CSI1_EN;
> > + io10 &= ~ADV748X_IO_10_CSI4_IN_SEL_AFE;
> > + if (is_txa(tx))
> > + io10 |= ADV748X_IO_10_CSI4_IN_SEL_AFE;
>
> Shouldn't the CSI4 be enabled here too? or are we assuming it's already
> (/always) enabled?
> io10 |= ADV748X_IO_10_CSI4_EN;
>
> > + else
> > + io10 |= ADV748X_IO_10_CSI4_EN |
> > + ADV748X_IO_10_CSI1_EN;
> > + } else {
> > + /* Clear AFE->TXA routing and power up TXA. */
> > + io10 &= ~ADV748X_IO_10_CSI4_IN_SEL_AFE;
> > + io10 |= ADV748X_IO_10_CSI4_EN;
>
> But if we assume it's already enabled ... do we need this?
> Perhaps it might be better to be explicit on this?
>
> > + }
> > + io_write(state, ADV748X_IO_10, io10);
>
>
> Would it be any cleaner to use io_clrset() here?
>
> Hrm ... also it feels like this register really should be set depending
> upon the complete state of ... &state->...
>
> So perhaps it deserves it's own function which should be called after
> csi_registered() callback and any link change.
>
> /me has a quick go at some psuedo codeishness...:
>
> int adv74x_io_10(struct adv748x_state *state);
> u8 bits = 0;
> u8 mask = ADV748X_IO_10_CSI1_EN
> | ADV748X_IO_10_CSI4_EN
> | ADV748X_IO_10_CSI4_IN_SEL_AFE;
>
> if (state->afe.tx) {
> /* AFE Requires TXA enabled, even when output to TXB */
> bits |= ADV748X_IO_10_CSI4_EN;
>
> if (is_txa(state->afe.tx))
> bits |= ADV748X_IO_10_CSI4_IN_SEL_AFE
> else
> bits |= ADV748X_IO_10_CSI1_EN;
> }
>
> if (state->hdmi.tx) {
> bits |= ADV748X_IO_10_CSI4_EN;
> }
>
> return io_clrset(state, ADV748X_IO_10, mask, bits);
> }
>
> How does that look ? (is it even correct first?)
>
Thanks, I've now updated the implementation to use something very
similar to what you proposed here!
Thanks
j
> > +
> > + return 0;
> > +}
> > +
> > +static const struct media_entity_operations adv748x_tx_media_ops = {
> > + .link_setup = adv748x_link_setup,
> > + .link_validate = v4l2_subdev_link_validate,
> > +};
> >
> > static const struct media_entity_operations adv748x_media_ops = {
> > .link_validate = v4l2_subdev_link_validate,
> > @@ -516,7 +570,8 @@ void adv748x_subdev_init(struct v4l2_subdev *sd, struct adv748x_state *state,
> > state->client->addr, ident);
> >
> > sd->entity.function = function;
> > - sd->entity.ops = &adv748x_media_ops;
> > + sd->entity.ops = is_tx(adv748x_sd_to_csi2(sd)) ?
> > + &adv748x_tx_media_ops : &adv748x_media_ops;
>
> Aha - yes that's a neat solution to ensure that only the TX links
> generate link_setup calls :)
>
>
>
> > }
> >
> > static int adv748x_parse_csi2_lanes(struct adv748x_state *state,
> > diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
> > index 6eb2e4a95eed..eb19c6cbbb4e 100644
> > --- a/drivers/media/i2c/adv748x/adv748x.h
> > +++ b/drivers/media/i2c/adv748x/adv748x.h
> > @@ -93,6 +93,7 @@ struct adv748x_csi2 {
> >
> > #define is_tx_enabled(_tx) ((_tx)->state->endpoints[(_tx)->port] != NULL)
> > #define __is_tx(_tx, _ab) ((_tx) == &(_tx)->state->tx##_ab)
> > +#define is_tx(_tx) (is_txa(_tx) || is_txb(_tx))
> > #define is_txa(_tx) __is_tx(_tx, a)
> > #define is_txb(_tx) __is_tx(_tx, b)
> >
> > @@ -224,6 +225,7 @@ struct adv748x_state {
> > #define ADV748X_IO_10_CSI4_EN BIT(7)
> > #define ADV748X_IO_10_CSI1_EN BIT(6)
> > #define ADV748X_IO_10_PIX_OUT_EN BIT(5)
> > +#define ADV748X_IO_10_CSI4_IN_SEL_AFE BIT(3)
>
>
>
> >
> > #define ADV748X_IO_CHIP_REV_ID_1 0xdf
> > #define ADV748X_IO_CHIP_REV_ID_2 0xe0
> >
>
> --
> Regards
> --
> Kieran
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prev parent reply other threads:[~2019-01-10 13:40 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-06 15:54 [PATCH v2 0/6] media: adv748x: Implement dynamic routing support Jacopo Mondi
2019-01-06 15:54 ` [PATCH v2 1/6] media: adv748x: Add is_txb() Jacopo Mondi
2019-01-07 9:49 ` Kieran Bingham
2019-01-07 10:05 ` Jacopo Mondi
2019-01-07 10:38 ` Kieran Bingham
2019-01-09 0:04 ` Laurent Pinchart
2019-01-06 15:54 ` [PATCH v2 2/6] media: adv748x: Rename reset procedures Jacopo Mondi
2019-01-07 9:59 ` Kieran Bingham
2019-01-06 15:54 ` [PATCH v2 3/6] media: adv748x: csi2: Link AFE with TXA and TXB Jacopo Mondi
2019-01-07 10:35 ` Kieran Bingham
2019-01-09 0:11 ` Laurent Pinchart
2019-01-06 15:54 ` [PATCH v2 4/6] media: adv748x: Store the source subdevice in TX Jacopo Mondi
2019-01-07 10:41 ` Kieran Bingham
2019-01-06 15:54 ` [PATCH v2 5/6] media: adv748x: Store the TX sink in HDMI/AFE Jacopo Mondi
2019-01-07 10:45 ` Kieran Bingham
2019-01-06 15:54 ` [PATCH v2 6/6] media: adv748x: Implement TX link_setup callback Jacopo Mondi
2019-01-07 12:36 ` Kieran Bingham
2019-01-09 0:15 ` Laurent Pinchart
2019-01-09 14:15 ` Kieran Bingham
2019-01-10 8:58 ` Jacopo Mondi
2019-01-10 10:05 ` Kieran Bingham
2019-01-10 8:51 ` Jacopo Mondi
2019-01-10 9:27 ` Laurent Pinchart
2019-01-09 14:17 ` Kieran Bingham
2019-01-10 10:01 ` Jacopo Mondi
2019-01-10 13:40 ` Jacopo Mondi [this message]
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