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From: Jacopo Mondi <jacopo@jmondi.org>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>,
	tomi.valkeinen@ideasonboard.com, sakari.ailus@linux.intel.com,
	niklas.soderlund@ragnatech.se, kieran.bingham@ideasonboard.com,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>,
	linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH v4 4/6] media: max9286: Use routes to configure link order
Date: Fri, 17 Dec 2021 14:38:16 +0100	[thread overview]
Message-ID: <20211217133816.smgsg7e7pj2jcvpp@uno.localdomain> (raw)
In-Reply-To: <Ybv3Z9bd51KTwvqD@pendragon.ideasonboard.com>

Hi Laurent,

On Fri, Dec 17, 2021 at 04:35:19AM +0200, Laurent Pinchart wrote:
> Hi Jacopo,
>
> Thank you for the patch.
>
> On Thu, Dec 16, 2021 at 06:47:44PM +0100, Jacopo Mondi wrote:
> > Use the routing table to configure the link output order and link
> > masking.
> >
> > The link output order defines the CSI-2 virtual channel a GSML stream
> > is output on. Configure ordering at stream start time and at chip
> > setup time. This last step requires to move the chip initialization
> > function after the V4L2 setup phase as it requires the subdev state from
> > where the routing table is retrieved from to be initialized.
>
> I wonder if we could drop some of the configuration from
> max9286_setup().

Do you mean move it to a later time ?

>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > ---
> >  drivers/media/i2c/max9286.c | 103 ++++++++++++++++++++++--------------
> >  1 file changed, 64 insertions(+), 39 deletions(-)
> >
> > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> > index 1395eb783dc0..5d728fa23f01 100644
> > --- a/drivers/media/i2c/max9286.c
> > +++ b/drivers/media/i2c/max9286.c
> > @@ -499,6 +499,61 @@ static int max9286_check_config_link(struct max9286_priv *priv,
> >  	return 0;
> >  }
> >
> > +/*
> > + * Configure the links output order (which defines on which CSI-2 VC a
> > + * link is output on) and configure link masking.
> > + */
> > +static void max9286_config_links(struct max9286_priv *priv)
> > +{
> > +	const struct v4l2_subdev_krouting *routing;
> > +	struct v4l2_subdev_state *state;
> > +	u8 link_order = 0;
> > +	u8 vc_mask = 0xf;
> > +	unsigned int i;
> > +
> > +	state = v4l2_subdev_lock_active_state(&priv->sd);
> > +	routing = &state->routing;
> > +
> > +	for (i = 0; i < routing->num_routes; ++i) {
> > +		struct v4l2_subdev_route *route = &routing->routes[i];
> > +
> > +		if (!(priv->route_mask & BIT(i)))
> > +			continue;
>
> Is this check needed ?
>

It is, I need to first assign a VC to the enabled routes.
I could replace it with for_each_active_route() probably!

> > +
> > +		/* Assign the CSI-2 VC using the source stream number. */
> > +		link_order |= route->source_stream << (2 * route->sink_pad);
> > +		vc_mask &= ~BIT(route->source_stream);
> > +	}
> > +
> > +	/*
> > +	 * This might look rather silly, but now that we have assigned a
> > +	 * VC to the enabled routes, we have to assign one to the disabled
> > +	 * routes as well, as there cannot be two sources with the same VC.
> > +	 */
> > +	for (i = 0; i < MAX9286_NUM_GMSL; ++i) {
> > +		unsigned int vc;
> > +
> > +		if (priv->route_mask & BIT(i))
> > +			continue;
> > +
> > +		/* ffs() counts from 1. */
> > +		vc = ffs(vc_mask) - 1;
>
> You can use __ffs(), which counts from 0 (but has an undefined behaviour
> when no bit is set).

That's why I didn't want to use it :)

>
> > +		link_order |= vc << (2 * i);
> > +		vc_mask &= ~BIT(vc);
> > +	}
> > +
> > +	/*
> > +	 * Use the enabled routes to enable GMSL links, configure the CSI-2
> > +	 * output order, mask unused links and autodetect link used as CSI
> > +	 * clock source.
> > +	 */
> > +	max9286_write(priv, 0x00, MAX9286_MSTLINKSEL_AUTO | priv->route_mask);
> > +	max9286_write(priv, 0x0b, link_order);
> > +	max9286_write(priv, 0x69, 0xf & ~priv->route_mask);
> > +
> > +	v4l2_subdev_unlock_state(state);
> > +}
> > +
> >  /* -----------------------------------------------------------------------------
> >   * V4L2 Subdev
> >   */
> > @@ -700,6 +755,8 @@ static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
> >  	int ret;
> >
> >  	if (enable) {
> > +		max9286_config_links(priv);
> > +
> >  		/*
> >  		 * The frame sync between cameras is transmitted across the
> >  		 * reverse channel as GPIO. We must open all channels while
> > @@ -1108,32 +1165,6 @@ static void max9286_v4l2_unregister(struct max9286_priv *priv)
> >
> >  static int max9286_setup(struct max9286_priv *priv)
> >  {
> > -	/*
> > -	 * Link ordering values for all enabled links combinations. Orders must
> > -	 * be assigned sequentially from 0 to the number of enabled links
> > -	 * without leaving any hole for disabled links. We thus assign orders to
> > -	 * enabled links first, and use the remaining order values for disabled
> > -	 * links are all links must have a different order value;
> > -	 */
> > -	static const u8 link_order[] = {
> > -		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxxx */
> > -		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxx0 */
> > -		(3 << 6) | (2 << 4) | (0 << 2) | (1 << 0), /* xx0x */
> > -		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xx10 */
> > -		(3 << 6) | (0 << 4) | (2 << 2) | (1 << 0), /* x0xx */
> > -		(3 << 6) | (1 << 4) | (2 << 2) | (0 << 0), /* x1x0 */
> > -		(3 << 6) | (1 << 4) | (0 << 2) | (2 << 0), /* x10x */
> > -		(3 << 6) | (1 << 4) | (1 << 2) | (0 << 0), /* x210 */
> > -		(0 << 6) | (3 << 4) | (2 << 2) | (1 << 0), /* 0xxx */
> > -		(1 << 6) | (3 << 4) | (2 << 2) | (0 << 0), /* 1xx0 */
> > -		(1 << 6) | (3 << 4) | (0 << 2) | (2 << 0), /* 1x0x */
> > -		(2 << 6) | (3 << 4) | (1 << 2) | (0 << 0), /* 2x10 */
> > -		(1 << 6) | (0 << 4) | (3 << 2) | (2 << 0), /* 10xx */
> > -		(2 << 6) | (1 << 4) | (3 << 2) | (0 << 0), /* 21x0 */
> > -		(2 << 6) | (1 << 4) | (0 << 2) | (3 << 0), /* 210x */
> > -		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* 3210 */
> > -	};
> > -
> >  	/*
> >  	 * Set the I2C bus speed.
> >  	 *
> > @@ -1143,13 +1174,7 @@ static int max9286_setup(struct max9286_priv *priv)
> >  	max9286_configure_i2c(priv, true);
> >  	max9286_reverse_channel_setup(priv, priv->init_rev_chan_mv);
> >
> > -	/*
> > -	 * Enable GMSL links, mask unused ones and autodetect link
> > -	 * used as CSI clock source.
> > -	 */
> > -	max9286_write(priv, 0x00, MAX9286_MSTLINKSEL_AUTO | priv->route_mask);
> > -	max9286_write(priv, 0x0b, link_order[priv->route_mask]);
> > -	max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
> > +	max9286_config_links(priv);
> >
> >  	/*
> >  	 * Video format setup:
> > @@ -1321,12 +1346,6 @@ static int max9286_init(struct device *dev)
> >  	if (ret)
> >  		return ret;
> >
> > -	ret = max9286_setup(priv);
> > -	if (ret) {
> > -		dev_err(dev, "Unable to setup max9286\n");
> > -		goto err_poc_disable;
> > -	}
> > -
> >  	/*
> >  	 * Register all V4L2 interactions for the MAX9286 and notifiers for
> >  	 * any subdevices connected.
> > @@ -1337,6 +1356,12 @@ static int max9286_init(struct device *dev)
> >  		goto err_poc_disable;
> >  	}
> >
> > +	ret = max9286_setup(priv);
> > +	if (ret) {
> > +		dev_err(dev, "Unable to setup max9286\n");
> > +		goto err_poc_disable;
> > +	}
> > +
> >  	ret = max9286_i2c_mux_init(priv);
> >  	if (ret) {
> >  		dev_err(dev, "Unable to initialize I2C multiplexer\n");
>
> --
> Regards,
>
> Laurent Pinchart

  reply	other threads:[~2021-12-17 13:37 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-16 17:47 [PATCH v4 0/6] media: max9286: Add multiplexed streams support Jacopo Mondi
2021-12-16 17:47 ` [PATCH v4 1/6] media: max9286: Add support for v4l2_subdev_state Jacopo Mondi
2021-12-16 18:33   ` Laurent Pinchart
2021-12-16 17:47 ` [PATCH v4 2/6] media: max9286: Implement set_routing Jacopo Mondi
2021-12-17  1:56   ` Laurent Pinchart
2021-12-17  2:18     ` Laurent Pinchart
2021-12-17  2:24       ` Laurent Pinchart
2021-12-17 13:28         ` Jacopo Mondi
2021-12-16 17:47 ` [PATCH v4 3/6] media: max9286: Use enabled routes to calculate pixelrate Jacopo Mondi
2021-12-17  2:29   ` Laurent Pinchart
2021-12-17 13:32     ` Jacopo Mondi
2021-12-16 17:47 ` [PATCH v4 4/6] media: max9286: Use routes to configure link order Jacopo Mondi
2021-12-17  2:35   ` Laurent Pinchart
2021-12-17 13:38     ` Jacopo Mondi [this message]
2021-12-16 17:47 ` [PATCH v4 5/6] media: max9286: Move format to subdev state Jacopo Mondi
2021-12-17  2:40   ` Laurent Pinchart
2021-12-17  3:09     ` Laurent Pinchart
2021-12-17 14:11       ` Jacopo Mondi
2024-05-09 13:11         ` Laurent Pinchart
2021-12-16 17:47 ` [PATCH v4 6/6] media: max9286: Implement get_frame_desc() Jacopo Mondi
2021-12-17  2:45   ` Laurent Pinchart
2021-12-17 14:12     ` Jacopo Mondi

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