Hi Niklas,
On Fri, Nov 13, 2020 at 12:19:00AM +0100, Niklas Söderlund wrote:
> Hi Jacopo,
>
> Thanks for your patch.
>
> On 2020-11-12 17:08:51 +0100, Jacopo Mondi wrote:
> > The VNCSI_IFMD register controls the data expansion mode and the
> > channel routing between the CSI-2 recivers and VIN instances.
> >
> > According to the chip manual revision 2.20 not all fields are available
> > for all the SoCs:
> > - V3M, V3H and E3 do not support the DES1 field has they do not feature
> > a CSI20 receiver.
> > - D3 only supports parallel input, and the whole register shall always
> > be written as 0.
> >
> > Add a bit mask to the per-SoC rcar_info structure and clear the register
> > value before writing it to the hardware.
> >
> > This patch upports the BSP change commit f54697394457
> > ("media: rcar-vin: Fix VnCSI_IFMD register access for r8a77990")
>
> I like that this issue is finally being addressed it's been in my list
> for a while. Unfortunately I'm not super keen on how it's solved here. I
> hoped the needed information could be extracted from the strcut
> rvin_info routes member inside rvin_set_channel_routing().
That's much more clever.
After all DES1 and DES0 availability only depends on the availability
of CSI20 and CSI40. It might be a bit more complex to make it nice in
the existing link_notify() callback due to it's complexity, but an
additional iteration of the routing table to collect which CSIx is
available should be quite cheap as you suggested
>
> For D3 the length of the routes will be 0 and the driver should not
> attempt to write to the register at all. In this patch the register is
> still written the value of VNCSI_IFMD_DES1 | VNCSI_IFMD_DES0.
Nope, for D3 the register is written as 0x00 (I've tested it) as the
mask gets & with !0xff
>
> For the rest I was hoping the routes array would be examined and tested
> for if it contains RVIN_CSI40, RVIN_CSI41, RVIN_CSI20 and RVIN_CSI21
> routes and set DES0 and DES1 bits accordingly.
>
> As rvin_set_channel_routing() is never called in a hot path the cost of
> iterating over the small array I think is worth it to guarantee the
> routes always are the authoritative source, just as it is for the media
> graph links.
Ack! Thanks for the suggestion, I'll report it in the v2 tags
Thanks
j
>
> >
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> > ---
> > drivers/media/platform/rcar-vin/rcar-core.c | 5 +++++
> > drivers/media/platform/rcar-vin/rcar-dma.c | 7 +++----
> > drivers/media/platform/rcar-vin/rcar-vin.h | 6 ++++++
> > 3 files changed, 14 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
> > index 0b67d58dd727..57ac43a93f5e 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-core.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> > @@ -1241,6 +1241,7 @@ static const struct rvin_info rcar_info_r8a77970 = {
> > .max_width = 4096,
> > .max_height = 4096,
> > .routes = rcar_info_r8a77970_routes,
> > + .ifmd_mask = VNCSI_IFMD_DES1,
> > };
> >
> > static const struct rvin_group_route rcar_info_r8a77980_routes[] = {
> > @@ -1270,6 +1271,7 @@ static const struct rvin_info rcar_info_r8a77980 = {
> > .max_width = 4096,
> > .max_height = 4096,
> > .routes = rcar_info_r8a77980_routes,
> > + .ifmd_mask = VNCSI_IFMD_DES1,
> > };
> >
> > static const struct rvin_group_route rcar_info_r8a77990_routes[] = {
> > @@ -1287,6 +1289,7 @@ static const struct rvin_info rcar_info_r8a77990 = {
> > .max_width = 4096,
> > .max_height = 4096,
> > .routes = rcar_info_r8a77990_routes,
> > + .ifmd_mask = VNCSI_IFMD_DES1,
> > };
> >
> > static const struct rvin_group_route rcar_info_r8a77995_routes[] = {
> > @@ -1306,6 +1309,8 @@ static const struct rvin_info rcar_info_r8a77995 = {
> > .max_height = 4096,
> > .routes = rcar_info_r8a77995_routes,
> > .scalers = rcar_info_r8a77995_scalers,
> > + /* VNCSI_IFMD_REG not available on R-Car D3. */
> > + .ifmd_mask = 0xff,
> > };
> >
> > static const struct of_device_id rvin_of_id_table[] = {
> > diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
> > index 378514a75bc2..c0e09c5d9c79 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-dma.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
> > @@ -134,8 +134,6 @@
> > #define VNDMR2_VLV(n) ((n & 0xf) << 12)
> >
> > /* Video n CSI2 Interface Mode Register (Gen3) */
> > -#define VNCSI_IFMD_DES1 (1 << 26)
> > -#define VNCSI_IFMD_DES0 (1 << 25)
> > #define VNCSI_IFMD_CSI_CHSEL(n) (((n) & 0xf) << 0)
> >
> > /* Video n scaling control register (Gen3) */
> > @@ -1583,8 +1581,9 @@ int rvin_set_channel_routing(struct rvin_dev *vin, u8 chsel)
> > vnmc = rvin_read(vin, VNMC_REG);
> > rvin_write(vin, vnmc & ~VNMC_VUP, VNMC_REG);
> >
> > - ifmd = VNCSI_IFMD_DES1 | VNCSI_IFMD_DES0 | VNCSI_IFMD_CSI_CHSEL(chsel);
> > -
> > + /* Write only available fields to IFMD_REG. */
> > + ifmd = (VNCSI_IFMD_DES0 | VNCSI_IFMD_DES1 | VNCSI_IFMD_CSI_CHSEL(chsel))
> > + & !vin->info->ifmd_mask;
> > rvin_write(vin, ifmd, VNCSI_IFMD_REG);
> >
> > vin_dbg(vin, "Set IFMD 0x%x\n", ifmd);
> > diff --git a/drivers/media/platform/rcar-vin/rcar-vin.h b/drivers/media/platform/rcar-vin/rcar-vin.h
> > index be10e06b0880..2cf8952faab1 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-vin.h
> > +++ b/drivers/media/platform/rcar-vin/rcar-vin.h
> > @@ -31,6 +31,10 @@
> > /* Max number on VIN instances that can be in a system */
> > #define RCAR_VIN_NUM 8
> >
> > +/* CSI_IFMD register bit fields to mask per-SoC. */
> > +#define VNCSI_IFMD_DES1 BIT(26)
> > +#define VNCSI_IFMD_DES0 BIT(25)
> > +
> > struct rvin_group;
> >
> > enum model_id {
> > @@ -174,6 +178,7 @@ struct rvin_group_scaler {
> > * @routes: list of possible routes from the CSI-2 recivers to
> > * all VINs. The list mush be NULL terminated.
> > * @scalers: List of available scalers, must be NULL terminated.
> > + * @ifmd_mask: Mask of unavailable bit fields of the CSI_IFMD register
> > */
> > struct rvin_info {
> > enum model_id model;
> > @@ -184,6 +189,7 @@ struct rvin_info {
> > unsigned int max_height;
> > const struct rvin_group_route *routes;
> > const struct rvin_group_scaler *scalers;
> > + u32 ifmd_mask;
> > };
> >
> > /**
> > --
> > 2.29.1
> >
>
> --
> Regards,
> Niklas Söderlund
