Hi Jacopo,
On 15/06/2020 09:43, Jacopo Mondi wrote:
> Hi Sakari,
>
> On Mon, Jun 15, 2020 at 11:34:06AM +0300, Sakari Ailus wrote:
>> Hi Jacopo,
>>
>> On Thu, Jun 11, 2020 at 06:16:51PM +0200, Jacopo Mondi wrote:
>>> Use the newly introduced get_mbus_config() subdevice pad operation to
>>> retrieve the remote subdevice MIPI CSI-2 bus configuration and configure
>>> the number of active data lanes accordingly.
>>>
>>> In order to be able to call the remote subdevice operation cache the
>>> index of the remote pad connected to the single CSI-2 input port.
>>>
>>> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
>>> ---
>>> drivers/media/platform/rcar-vin/rcar-csi2.c | 61 ++++++++++++++++++++-
>>> 1 file changed, 58 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
>>> index 151e6a90c5fb..11769f004fd8 100644
>>> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
>>> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
>>> @@ -363,6 +363,7 @@ struct rcar_csi2 {
>>> struct v4l2_async_notifier notifier;
>>> struct v4l2_async_subdev asd;
>>> struct v4l2_subdev *remote;
>>> + unsigned int remote_pad;
>>>
>>> struct v4l2_mbus_framefmt mf;
>>>
>>> @@ -371,6 +372,7 @@ struct rcar_csi2 {
>>>
>>> unsigned short lanes;
>>> unsigned char lane_swap[4];
>>> + unsigned short active_lanes;
>>
>> Do you need this? I.e. should you not always request this from the
>> transmitter device?
>
> It's actually the other way around. The receiver queries the
> transmitter to know how many data lanes it intends to use and adjusts
> its configuration to accommodate it.
>
>>
>>> };
>>>
>>> static inline struct rcar_csi2 *sd_to_csi2(struct v4l2_subdev *sd)
>>> @@ -414,7 +416,7 @@ static int rcsi2_wait_phy_start(struct rcar_csi2 *priv)
>>>
>>> /* Wait for the clock and data lanes to enter LP-11 state. */
>>> for (timeout = 0; timeout <= 20; timeout++) {
>>> - const u32 lane_mask = (1 << priv->lanes) - 1;
>>> + const u32 lane_mask = (1 << priv->active_lanes) - 1;
>>>
>>> if ((rcsi2_read(priv, PHCLM_REG) & PHCLM_STOPSTATECKL) &&
>>> (rcsi2_read(priv, PHDLM_REG) & lane_mask) == lane_mask)
>>> @@ -471,11 +473,57 @@ static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
>>> * bps = link_freq * 2
>>> */
>>> mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * bpp;
>>> - do_div(mbps, priv->lanes * 1000000);
>>> + do_div(mbps, priv->active_lanes * 1000000);
>>>
>>> return mbps;
>>> }
>>>
>>> +static int rcsi2_config_active_lanes(struct rcar_csi2 *priv)
>>> +{
>>> + struct v4l2_mbus_config mbus_config = { 0 };
>>> + unsigned int num_lanes = (-1U);
>>> + int ret;
>>> +
>>> + priv->active_lanes = priv->lanes;
>>> + ret = v4l2_subdev_call(priv->remote, pad, get_mbus_config,
>>> + priv->remote_pad, &mbus_config);
>>> + if (ret == -ENOIOCTLCMD) {
>>> + dev_dbg(priv->dev, "No remote mbus configuration available\n");
>>> + return 0;
>>> + }
>>> +
>>> + if (ret) {
>>> + dev_err(priv->dev, "Failed to get remote mbus configuration\n");
>>> + return ret;
>>> + }
>>> +
>>> + if (mbus_config.type != V4L2_MBUS_CSI2_DPHY) {
>>> + dev_err(priv->dev, "Unsupported media bus type %u\n",
>>> + mbus_config.type);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + if (mbus_config.flags & V4L2_MBUS_CSI2_1_LANE)
>>> + num_lanes = 1;
>>> + else if (mbus_config.flags & V4L2_MBUS_CSI2_2_LANE)
>>> + num_lanes = 2;
>>> + else if (mbus_config.flags & V4L2_MBUS_CSI2_3_LANE)
>>> + num_lanes = 3;
>>> + else if (mbus_config.flags & V4L2_MBUS_CSI2_4_LANE)
>>> + num_lanes = 4;
>>
>> This is the downside of using flags... Anyway, I guess this is certainly
>> fine now.
>>
>
> Let's change this on top, if we like to (and I would like to :)
That answers my question then ;-)
--
Kieran
>
> Thanks
> j
>
>>> +
>>> + if (num_lanes > priv->lanes) {
>>> + dev_err(priv->dev,
>>> + "Unsupported mbus config: too many data lanes %u\n",
>>> + num_lanes);
>>> + return -EINVAL;
>>> + }
>>> +
>>> + priv->active_lanes = num_lanes;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>>> {
>>> const struct rcar_csi2_format *format;
>>> @@ -490,6 +538,11 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>>> /* Code is validated in set_fmt. */
>>> format = rcsi2_code_to_fmt(priv->mf.code);
>>>
>>> + /* Get the remote mbus config to get the number of enabled lanes. */
>>> + ret = rcsi2_config_active_lanes(priv);
>>> + if (ret)
>>> + return ret;
>>> +
>>> /*
>>> * Enable all supported CSI-2 channels with virtual channel and
>>> * data type matching.
>>> @@ -522,7 +575,7 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>>> }
>>>
>>> phycnt = PHYCNT_ENABLECLK;
>>> - phycnt |= (1 << priv->lanes) - 1;
>>> + phycnt |= (1 << priv->active_lanes) - 1;
>>>
>>> mbps = rcsi2_calc_mbps(priv, format->bpp);
>>> if (mbps < 0)
>>> @@ -748,6 +801,7 @@ static int rcsi2_notify_bound(struct v4l2_async_notifier *notifier,
>>> }
>>>
>>> priv->remote = subdev;
>>> + priv->remote_pad = pad;
>>>
>>> dev_dbg(priv->dev, "Bound %s pad: %d\n", subdev->name, pad);
>>>
>>> @@ -793,6 +847,7 @@ static int rcsi2_parse_v4l2(struct rcar_csi2 *priv,
>>> priv->lanes);
>>> return -EINVAL;
>>> }
>>> + priv->active_lanes = priv->lanes;
>>>
>>> for (i = 0; i < ARRAY_SIZE(priv->lane_swap); i++) {
>>> priv->lane_swap[i] = i < priv->lanes ?
>>
>> --
>> Kind regards,
>>
>> Sakari Ailus
--
Regards
--
Kieran
