Re: [PATCH 2/2] tpm2: Add a TPMv2 MMIO TIS driver

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

[...]
> > > Should be a uclass interface.
> > >
> >
> > Why? A uclass is supposed to describe and abstract hardware.  This is just
> > a specific implementation of a TPM, not all TPMs are TIS compliant. We already
> > have a uclass for those.
> 
> Who told you that a uclass is supposed to describe and abstract hardware? :-)
> 

That's what I've mostly seen it used for, maybe i got the idea wrong.

> The uclass is how driver model does APIs, so normally a uclass would
> be used for any API. There are exceptions, but this one actually looks
> like a useful interface we should have.
> 

the point is we already have a uclass for tpm devices.  So why should the
we add another one that just describes the TIS interface?

> >
> > > > +       .read_bytes = mmio_read_bytes,
> > > > +       .write_bytes = mmio_write_bytes,
> > > > +       .read16 = mmio_read16,
> > > > +       .read32 = mmio_read32,
> > > > +       .write32 = mmio_write32,
> > > > +};
> > > > +
> > > > +static int tpm_tis_probe(struct udevice *udev)
> > > > +{
> > > > +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> > > > +       struct tpm_chip_priv *priv = dev_get_uclass_priv(udev);
> > > > +       int ret = 0;
> > > > +       fdt_addr_t ioaddr;
> > > > +       u64 sz;
> > > > +
> > > > +       ioaddr = dev_read_addr(udev);
> > > > +       if (ioaddr == FDT_ADDR_T_NONE)
> > > > +               return -EINVAL;
> > >
> > > consider this for easier debugging:
> > >
> > >    return log_msg_ret("ioaddr", -EINVAL);
> > >
> >
> > Sure
> >
> > > > +
> > > > +       ret = dev_read_u64(udev, "reg", &sz);
> > > > +       if (ret)
> > > > +               return -EINVAL;
> > > > +
> > > > +       drv_data->iobase = ioremap(ioaddr, sz);
> > > > +       log_info("Remapped TPM2 base: 0x%llx size: 0x%llx\n", ioaddr, sz);
> > >
> > > log_debug() I think?
> > >
> > Yea, that's a leftover of my initial code, were I needed to make sure the
> > ioremap worked.
> >
> > > > +       tpm_tis_ops_register(udev, &phy_ops);
> > > > +       ret = tpm_tis_init(udev);
> > > > +       if (ret)
> > > > +               goto iounmap;
> > > > +
> > > > +       priv->pcr_count = drv_data->pcr_count;
> > > > +       priv->pcr_select_min = drv_data->pcr_select_min;
> > > > +       /*
> > > > +        * Although the driver probably works with a TPMv1 our Kconfig
> > > > +        * limits the driver to TPMv2 only
> > > > +        */
> > > > +       priv->version = TPM_V2;
> > > > +
> > > > +       return ret;
> > > > +iounmap:
> > > > +       iounmap(drv_data->iobase);
> > > > +       return -EINVAL;
> > > > +}
> > > > +
> > > > +static int tpm_tis_remove(struct udevice *udev)
> > > > +{
> > > > +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> > > > +
> > > > +       iounmap(drv_data->iobase);
> > > > +       return tpm_tis_cleanup(udev);
> > > > +}
> > > > +
> > > > +static const struct tpm_ops tpm_tis_ops = {
> > > > +       .open           = tpm_tis_open,
> > > > +       .close          = tpm_tis_close,
> > > > +       .get_desc       = tpm_tis_get_desc,
> > > > +       .send           = tpm_tis_send,
> > > > +       .recv           = tpm_tis_recv,
> > > > +       .cleanup        = tpm_tis_cleanup,
> > > > +};
> > > > +
> > > > +static const struct tpm_tis_chip_data tpm_tis_std_chip_data = {
> > > > +       .pcr_count = 24,
> > > > +       .pcr_select_min = 3,
> > > > +};
> > > > +
> > > > +static const struct udevice_id tpm_tis_ids[] = {
> > > > +       {
> > > > +               .compatible = "tcg,tpm-tis-mmio",
> > > > +               .data = (ulong)&tpm_tis_std_chip_data,
> > > > +       },
> > > > +       { }
> > > > +};
> > > > +
> > > > +U_BOOT_DRIVER(tpm_tis_mmio) = {
> > > > +       .name   = "tpm_tis_mmio",
> > > > +       .id     = UCLASS_TPM,
> > > > +       .of_match = tpm_tis_ids,
> > > > +       .ops    = &tpm_tis_ops,
> > > > +       .probe  = tpm_tis_probe,
> > > > +       .remove = tpm_tis_remove,
> > > > +       .priv_auto      = sizeof(struct tpm_chip),
> > > > +};
> > > > --
> > > > 2.32.0.rc0
> > > >
> > >
> > > Regards,
> > > Simon
> >
> > Thanks for looking at this
> > /Ilias
> 
> Likewise.
> 
> Regards,
> Simon