Hi Niklas, Thank you for the patch. On Thursday, 26 April 2018 23:21:21 EEST Niklas Söderlund wrote: > A V4L2 driver for Renesas R-Car MIPI CSI-2 receiver. The driver > supports the R-Car Gen3 SoCs where separate CSI-2 hardware blocks are > connected between the video sources and the video grabbers (VIN). > > Driver is based on a prototype by Koji Matsuoka in the Renesas BSP. > > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx> > Reviewed-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > Reviewed-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx> > Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > --- > > * Changes since v13 > - Change return rcar_csi2_formats + i to return &rcar_csi2_formats[i]. > - Add define for PHCLM_STOPSTATECKL. > - Update spelling in comments. > - Update calculation in rcar_csi2_calc_phypll() according to > https://linuxtv.org/downloads/v4l-dvb-apis/kapi/csi2.html. The one > before v14 did not take into account that 2 bits per sample is > transmitted. Just one small comment about this, please see below. > - Use Geert's suggestion of (1 << priv->lanes) - 1 instead of switch > statement to set correct number of lanes to enable. > - Change hex constants in hsfreqrange_m3w_h3es1[] to lower case to match > style of rest of file. > - Switch to %u instead of 0x%x when printing bus type. > - Switch to %u instead of %d for priv->lanes which is unsigned. > - Add MEDIA_BUS_FMT_YUYV8_1X16 to the list of supported formats in > rcar_csi2_formats[]. > - Fixed bps for MEDIA_BUS_FMT_YUYV10_2X10 to 20 and not 16. > - Set INTSTATE after PL-11 is confirmed to match flow chart in > datasheet. > - Change priv->notifier.subdevs == NULL to !priv->notifier.subdevs. > - Add Maxime's and laurent's tags. > --- > drivers/media/platform/rcar-vin/Kconfig | 12 + > drivers/media/platform/rcar-vin/Makefile | 1 + > drivers/media/platform/rcar-vin/rcar-csi2.c | 883 ++++++++++++++++++++ > 3 files changed, 896 insertions(+) > create mode 100644 drivers/media/platform/rcar-vin/rcar-csi2.c [snip] > diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c > b/drivers/media/platform/rcar-vin/rcar-csi2.c new file mode 100644 > index 0000000000000000..49b29d5680f9d80b > --- /dev/null > +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c [snip] > +static int rcar_csi2_calc_phypll(struct rcar_csi2 *priv, unsigned int bpp, > + u32 *phypll) > +{ > + const struct phypll_hsfreqrange *hsfreq; > + struct v4l2_subdev *source; > + struct v4l2_ctrl *ctrl; > + u64 mbps; > + > + if (!priv->remote) > + return -ENODEV; > + > + source = priv->remote; > + > + /* Read the pixel rate control from remote */ > + ctrl = v4l2_ctrl_find(source->ctrl_handler, V4L2_CID_PIXEL_RATE); > + if (!ctrl) { > + dev_err(priv->dev, "no pixel rate control in subdev %s\n", > + source->name); > + return -EINVAL; > + } > + > + /* > + * Calculate the phypll in mbps (from v4l2 documentation) > + * link_freq = (pixel_rate * bits_per_sample) / (2 * nr_of_lanes) > + */ > + mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * bpp; > + do_div(mbps, priv->lanes * 2000000); pixel rate * bits per sample will give you the overall bit rate, which you then divide by the number of lanes to get the bitrate per lane, and then by 2 as D-PHY is a DDR PHY and transmits 2 bits per clock cycle. You then end up with the link frequency, which is thus expressed in MHz, not in Mbps. I would thus name the mbps variable freq, and rename the phypll_hsfreqrange mbps field to freq (maybe with a small comment right after the field to tell the value is expressed in MHz). > + for (hsfreq = priv->info->hsfreqrange; hsfreq->mbps != 0; hsfreq++) > + if (hsfreq->mbps >= mbps) > + break; > + > + if (!hsfreq->mbps) { > + dev_err(priv->dev, "Unsupported PHY speed (%llu Mbps)", mbps); > + return -ERANGE; > + } > + > + dev_dbg(priv->dev, "PHY HSFREQRANGE requested %llu got %u Mbps\n", mbps, > + hsfreq->mbps); > + > + *phypll = PHYPLL_HSFREQRANGE(hsfreq->reg); > + > + return 0; > +} [snip] -- Regards, Laurent Pinchart
