Hi Ilias,
On Fri, 8 Jul 2022 at 02:24, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
Hi Simon,
[...]
UCLASS_DRIVER(tpm) = {
.id = UCLASS_TPM,.name = "tpm",.flags = DM_UC_FLAG_SEQ_ALIAS,
.id = UCLASS_TPM,.name = "tpm",.flags = DM_UC_FLAG_SEQ_ALIAS,#if CONFIG_IS_ENABLED(OF_REAL)
.post_bind = dm_scan_fdt_dev,
.post_bind = dm_scan_fdt_dev,#endif
.post_probe = tpm_uclass_post_probe, .per_device_auto = sizeof(struct tpm_chip_priv),};
2.25.1
The driver needs a compatible string so it can be in the device tree.
Why? I've tried to hint this on the previous iteration of the patch. The RNG here is not a *device*. The TPM is the device and you are guaranteed to have an RNG. The way to get a random number is send a special command to the TPM. So all that we should do here is leverage the fact that the TPM is already in the device tree.
And fwiw we should stick to try to stick to what the DT spec defines as much as possible. I personally don't see this as a special usecase were deviating from the spec is justified.
This is not a deviation from a spec. What spec? Also, I don't want to get into another discussion about what a device is. We can disagree on that if you like.
One reason is that U-Boot generally requires compatible strings, e.g. with of-platdata. But also we can refer to the rand device from elsewhere in the tree. I know that Linux does lots of ad-hoc device creation and doesn't really have the concept of a uclass consistently applied, but this is U-Boot.
So please add a compatible string sow e can use it in the DT.
\Regards, Simon