Re: [PATCH v5 2/3] media: imx: add a driver for i.MX8MQ mipi csi rx phy and controller

[Martin Kepplinger]

Am Dienstag, dem 13.07.2021 um 00:52 +0300 schrieb Laurent Pinchart:
> Hi Martin,
> 
> Thank you for the patch.

thank you for reviewing!

> 
> On Fri, Jun 18, 2021 at 11:57:52AM +0200, Martin Kepplinger wrote:
> > Add a driver to support the i.MX8MQ MIPI CSI receiver. The hardware
> > side
> > is based on
> >  
> > https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/media/platform/imx8/mxc-mipi-csi2_yav.c?h=imx_5.4.70_2.3.0
> > 
> > It's built as part of VIDEO_IMX7_CSI because that's documented to
> > support
> > i.MX8M platforms. This driver adds i.MX8MQ support where currently
> > only the
> > i.MX8MM platform has been supported.
> 
> Overall this is really nice work. I have quite a few review comments,
> but hopefully nothing that should be difficult to handle.

I think so too but right now I have one question:

> 
> > Signed-off-by: Martin Kepplinger <martin.kepplinger@xxxxxxx>
> > ---
> >  drivers/staging/media/imx/Makefile           |   1 +
> >  drivers/staging/media/imx/imx8mq-mipi-csi2.c | 963
> > +++++++++++++++++++
> >  2 files changed, 964 insertions(+)
> >  create mode 100644 drivers/staging/media/imx/imx8mq-mipi-csi2.c
> > 
> > 


> > +static int imx8mq_mipi_csi_pm_suspend(struct device *dev, bool
> > runtime)
> > +{
> > +       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > +       struct csi_state *state = mipi_sd_to_csi2_state(sd);
> > +       int ret = 0;
> > +
> > +       mutex_lock(&state->lock);
> > +
> > +       if (state->state & ST_POWERED) {
> > +               imx8mq_mipi_csi_stop_stream(state);
> > +               imx8mq_mipi_csi_clk_disable(state);
> > +               state->state &= ~ST_POWERED;
> > +               if (!runtime)
> > +                       state->state |= ST_SUSPENDED;
> > +       }
> > +
> > +       mutex_unlock(&state->lock);
> > +
> > +       ret = icc_set_bw(state->icc_path, 0, 0);
> > +       if (ret)
> > +               dev_err(dev, "icc_set_bw failed with %d\n", ret);
> > +
> > +       return ret ? -EAGAIN : 0;
> > +}
> > +
> > +static int imx8mq_mipi_csi_pm_resume(struct device *dev, bool
> > runtime)
> > +{
> > +       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > +       struct csi_state *state = mipi_sd_to_csi2_state(sd);
> > +       int ret = 0;
> > +
> > +       ret = icc_set_bw(state->icc_path, 0, state->icc_path_bw);
> > +       if (ret) {
> > +               dev_err(dev, "icc_set_bw failed with %d\n", ret);
> > +               return ret;
> > +       }
> > +
> > +       mutex_lock(&state->lock);
> > +
> > +       if (!runtime && !(state->state & ST_SUSPENDED))
> > +               goto unlock;
> > +
> > +       if (!(state->state & ST_POWERED)) {
> > +               state->state |= ST_POWERED;
> > +               ret = imx8mq_mipi_csi_clk_enable(state);
> 
> Enabling the clocks in the PM resume handler is correct, but they
> should
> also be disabled in the PM suspend handler.

imx8mq_mipi_csi_clk_disable() is called in suspend(). I don't know what
you mean here.


again, thank you for reviewing,

                                       martin