On 12/13/24 13:22, Luca Weiss wrote:
On Fri Dec 13, 2024 at 12:02 PM CET, Vladimir Zapolskiy wrote:
On 12/9/24 14:32, Bryan O'Donoghue wrote:
On 09/12/2024 12:01, Luca Weiss wrote:
Currently the Qualcomm CAMSS driver only supports D-PHY while the
hardware on most SoCs also supports C-PHY. Until this support is added,
check for D-PHY to make it somewhat explicit that C-PHY won't work.
Signed-off-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx>
---
drivers/media/platform/qcom/camss/camss.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
index 9fb31f4c18adee886cd0bcf84438a8f27635e07f..b99af35074cdf6fa794a0d2f0d54ecf12ac354d9 100644
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -1855,6 +1855,15 @@ static int camss_of_parse_endpoint_node(struct device *dev,
if (ret)
return ret;
+ /*
+ * Most SoCs support both D-PHY and C-PHY standards, but currently only
+ * D-PHY is supported in the driver.
+ */
+ if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
+ dev_err(dev, "Unsupported bus type %d\n", vep.bus_type);
+ return -EINVAL;
+ }
+
Looks like it would break all old board dtbs, which is not just bad, but NAK.
V4L2_MBUS_UNKNOWN shall be properly handled without the risk of regressions.
Please see drivers/media/v4l2-core/v4l2-fwnode.c around line 218.
The code there sets bus_type if it's UNKNOWN
if (bus_type == V4L2_MBUS_UNKNOWN)
vep->bus_type = V4L2_MBUS_CSI2_DPHY;
So setting "bus-type" in dt is not necessary, even if it makes things
more explicit from dt side. I don't think we'll ever get UNKNOWN here in
camss.
Thank you for pointing it out, I haven't tested the change yet, but hopefully
I will find time today to do it later on, it should exclude any doubts.
--
Best wishes,
Vladimir
