arm64: dts: Sort out CM5 and I/O board I2C ports #6441
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| // SPDX-License-Identifier: GPL-2.0 | |||
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| i2c_csi_dsi0: &i2c0 { // Note: For CAM0 and DISP0 connectors | |||
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I haven't looked at the pinout, but CM5 only has 2 MIPI PHY ports, so do CAM0 and DISP0 actually connect to anything other than the I2C?
I'm sure Dominic made a comment in passing yesterday that CAM0 and DISP0 pins on the CM were repurposed for USB3.
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This is the connectivity table I ended up with:
CM5 CM4IO CM5IO
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DPHY0 CAM1 CAMDISP0
DPHY1 DISP1 CAMDISP1
GPIO0/1 CAM0, DISP0 CAMDISP1
GPIO38/39 CAM1, DISP1 CAMDISP0
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This means that CAM0 and DISP0 are not usable for cameras or displays, which is the better of the two options because that I2C port is effectively shared with ID_SC and ID_SD. The i2c_csi_dsi0 parameter is there for compatibility with any existing I2C setup. i2c_csi_dsi1 (and its alias i2c_csi_dsi) is assigned to CAM1 and DISP1.
| symlink = "i2c-10"; | ||
| }; | ||
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| i2c_csi_dsi1: &i2c6 { // Note: For CAM1, DISP1, on-board RTC, and fan controller |
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And seeing as CAM1 and DISP1 share an I2C port, if the above is true about the MIPI wiring, that means we can't run two identical cameras or displays on CM5 with CM4IO (fine on CM5IO).
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Yes, I believe that's correct.
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I believe this is the best we can do for CM4IO - people should use CM5IO to get the most out of CM5. |
There is a difference in I2C usage between CM4IO and CM5IO. Present a simple, consistent view of the world by moving the assignment of the bus IDs into carrier-specific files. CM5 has reduced connectivity on CM4IO - the DPHYs are connected to CAM1 and DISP1. Keep i2c-10 for use with that pair, as is the case for CM4 on CM4IO. Fixes: 36faab6 ("dts: bcm2712-rpi: Add aliases for the CSI/DSI I2Cs") See: raspberrypi#6421 Signed-off-by: Phil Elwell <[email protected]>
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Unless somebody discovers a problem, this is the final iteration. From the updated commit message: |
kernel: drivers: media: bcm2835_isp: Cache LS table dmabuf See: raspberrypi/linux#6429 kernel: arm64: dts: Sort out CM5 and I/O board I2C ports See: raspberrypi/linux#6441 kernel: cgroup: Use kernel command line to disable memory cgroup See: raspberrypi/linux#6439
kernel: drivers: media: bcm2835_isp: Cache LS table dmabuf See: raspberrypi/linux#6429 kernel: arm64: dts: Sort out CM5 and I/O board I2C ports See: raspberrypi/linux#6441 kernel: cgroup: Use kernel command line to disable memory cgroup See: raspberrypi/linux#6439
There is a difference in I2C usage between CM4IO and CM5IO. Present a simple, consistent view of the world by moving the assignment of the bus IDs into carrier-specific files.
Fixes: 36faab6 ("dts: bcm2712-rpi: Add aliases for the CSI/DSI I2Cs")
See: #6421