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@xxxxxxxxxx>
> ---
> 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?)
> +
> + 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
