Hi Sakari, > -----Original Message----- > From: Sakari Ailus [mailto:sakari.ailus@xxxxxx] > Sent: Tuesday, June 18, 2019 8:29 PM > To: Vishal Sagar <vsagar@xxxxxxxxxx> > Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>; Vishal Sagar > <vishal.sagar@xxxxxxxxxx>; Hyun Kwon <hyunk@xxxxxxxxxx>; > laurent.pinchart@xxxxxxxxxxxxxxxx; mchehab@xxxxxxxxxx; > robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; Michal Simek > <michals@xxxxxxxxxx>; linux-media@xxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; hans.verkuil@xxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Dinesh Kumar > <dineshk@xxxxxxxxxx>; Sandip Kothari <sandipk@xxxxxxxxxx>; Luca Ceresoli > <luca@xxxxxxxxxxxxxxxx>; Jacopo Mondi <jacopo@xxxxxxxxxx> > Subject: Re: [PATCH v8 2/2] media: v4l: xilinx: Add Xilinx MIPI CSI-2 Rx > Subsystem driver > > Hi Vishal, > > On Fri, Jun 07, 2019 at 07:11:47AM +0000, Vishal Sagar wrote: > ... > > > > +/** > > > > + * xcsi2rxss_s_ctrl - This is used to set the Xilinx MIPI CSI-2 V4L2 controls > > > > + * @ctrl: V4L2 control to be set > > > > + * > > > > + * This function is used to set the V4L2 controls for the Xilinx MIPI > > > > + * CSI-2 Rx Subsystem. It is used to set the active lanes in the system. > > > > + * The event counters can be reset. > > > > + * > > > > + * Return: 0 on success, errors otherwise > > > > + */ > > > > +static int xcsi2rxss_s_ctrl(struct v4l2_ctrl *ctrl) > > > > +{ > > > > + struct xcsi2rxss_state *xcsi2rxss = > > > > + container_of(ctrl->handler, struct xcsi2rxss_state, > > > > + ctrl_handler); > > > > + struct xcsi2rxss_core *core = &xcsi2rxss->core; > > > > + int ret = 0; > > > > + > > > > + mutex_lock(&xcsi2rxss->lock); > > > > + > > > > + switch (ctrl->id) { > > > > + case V4L2_CID_XILINX_MIPICSISS_ACT_LANES: > > > > + /* > > > > + * This will be called only when "Enable Active Lanes" parameter > > > > + * is set in design > > > > + */ > > > > > > You generally get the number of lanes from firmware. There's no need to > add > > > a control for it. > > > > > > > I don't understand what firmware means here. There is no other code > running. > > I don't see how to modify the number of lanes apart from using v4l control. > > It's not the user that provides this information. Again, if you want this > feature right from the time the driver is merged to mainline, then rebase > the set on top of Jacopo's frame descriptor set. But it may take a while. > Thanks for reviewing again and sharing this. Since Jacopo's frame descriptor set will take a while, I will remove this control for now from the driver so that the driver can get into upstream. Regards Vishal Sagar > > > > > > + if (core->enable_active_lanes) { > > > > + u32 active_lanes; > > > > + > > > > + xcsi2rxss_clr_and_set(core, XCSI_PCR_OFFSET, > > > > + XCSI_PCR_ACTLANES_MASK, > > > > + ctrl->val - 1); > > > > + /* > > > > + * This delay is to allow the value to reflect as write > > > > + * and read paths are different. > > > > + */ > > > > + udelay(1); > > > > + active_lanes = xcsi2rxss_read(core, XCSI_PCR_OFFSET); > > > > + active_lanes &= XCSI_PCR_ACTLANES_MASK; > > > > + active_lanes++; > > > > + if (active_lanes != ctrl->val) > > > > + dev_info(core->dev, "RxByteClkHS absent\n"); > > > > + dev_dbg(core->dev, "active lanes = %d\n", ctrl->val); > > > > + } else { > > > > + ret = -EINVAL; > > > > + } > > > > + break; > > > > + case V4L2_CID_XILINX_MIPICSISS_RESET_COUNTERS: > > > > + xcsi2rxss_reset_event_counters(xcsi2rxss); > > > > + break; > > > > + default: > > > > + ret = -EINVAL; > > > > + break; > > > > + } > > > > + > > > > + mutex_unlock(&xcsi2rxss->lock); > > > > + > > > > + return ret; > > > > +} > > -- > Regards, > > Sakari Ailus
