Does TX2 BSP support mipi csi C-PHY

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

Hi everybody,
Our customer use C-PHY camera they want our product support the camera. Does TX2 BSP support MIPI CSI C-PHY? Thanks!

2

I have not seen anything in the specification that says it supports the tri-lane tri-signal format of C-PHY.
I’d love to be proven wrong, but my conclusion so far is “no.”

3

hi kenny_cz,

TX2 CSI-2 host solution (referred to as NVCSI) can support both MIPI D-PHY, v1.2, and MIPI C-PHY, physical layer options.

you could refer to Tegra X2 (Parker Series SoC) Technical Reference Manual, check MIPI CAMERA SERIAL INTERFACE (CSI) chapter for more details.
thanks

4

Hello,

The TX2 datasheet says the hardware does supprt CSI C-PHY, how about the software?

Thanks,

TK

5

hello tk60,

please refer to kernel sources, it supported DPHY by default.
/kernel_src/kernel/kernel-4.4/drivers/media/platform/tegra/camera/csi/csi4_fops.c

you may have modification to configure the PHY mode to CPHY.
thanks

6

Hi Jerry,

I don’t understand, I assume BSP software development is Nvidia’s responsibility and does better job, while Nvidia’s users should focus on their applications, am I right?

Thanks,

TK

7

hello tk60,

actually, we had hard-code the PHY mode, you should update low-level CSI drivers also.
for example,
/kernel_src/kernel/kernel-4.4/drivers/media/platform/tegra/camera/csi/csi4_fops.c

static void csi4_phy_config(
	struct tegra_csi_channel *chan, int csi_port,
	int csi_lanes, bool enable)
{
...
	/* set to DPHY */
	csi4_phy_write(chan, phy_num, NVCSI_CIL_PHY_CTRL, DPHY);

to be honest, we did not have fully tests for CPHY sensors based-on l4t-r28.2.1/Jetson-TX2.
we testing with CPHY sensors start from l4t-r31.1/Jetson-Xavier.
thanks

8

Hi Jerry,

We don’t use Xavier for product development and I don’t have any knowledge about it yet. Can I move Xavier C-Phy socurce code to TX2 source tree to enable it?

Thanks,

TK

9

hello tk60,

please check comment #7, you should update TX2’s CSI driver to enable C-PHY.
please also note that Xavier(csi5) and TX2(csi4) were using different CSI drivers. thanks