On Fri Aug 2, 2024 at 6:19 PM EEST, Jett Rink wrote:
> Could I get some feedback on this patch please? Is there something I
> am not doing correctly?
Sorry, I just came from holidays.
>
> -Jett
>
> On Thu, Jul 18, 2024 at 2:24 PM Jett Rink <jettrink@xxxxxxxxxxxx> wrote:
> >
> > Accept another DID:VID for the next generation Google TPM. This TPM
> > has the same Ti50 firmware and fulfills the same interface.
> >
> > Signed-off-by: Jett Rink <jettrink@xxxxxxxxxxxx>
> > ---
> >
> > Changes in v2:
> > Patchset 2 applies cleanly
> >
> > drivers/char/tpm/tpm_tis_i2c_cr50.c | 11 ++++++++---
> > 1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c
> > index adf22992138e..b50005ccfc5e 100644
> > --- a/drivers/char/tpm/tpm_tis_i2c_cr50.c
> > +++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c
> > @@ -31,7 +31,8 @@
> > #define TPM_CR50_TIMEOUT_SHORT_MS 2 /* Short timeout during transactions */
> > #define TPM_CR50_TIMEOUT_NOIRQ_MS 20 /* Timeout for TPM ready without IRQ */
> > #define TPM_CR50_I2C_DID_VID 0x00281ae0L /* Device and vendor ID reg value */
> > -#define TPM_TI50_I2C_DID_VID 0x504a6666L /* Device and vendor ID reg value */
> > +#define TPM_TI50_DT_I2C_DID_VID 0x504a6666L /* Device and vendor ID reg value */
> > +#define TPM_TI50_OT_I2C_DID_VID 0x50666666L /* Device and vendor ID reg value */
> > #define TPM_CR50_I2C_MAX_RETRIES 3 /* Max retries due to I2C errors */
> > #define TPM_CR50_I2C_RETRY_DELAY_LO 55 /* Min usecs between retries on I2C */
> > #define TPM_CR50_I2C_RETRY_DELAY_HI 65 /* Max usecs between retries on I2C */
> > @@ -741,14 +742,18 @@ static int tpm_cr50_i2c_probe(struct i2c_client *client)
> > }
> >
> > vendor = le32_to_cpup((__le32 *)buf);
> > - if (vendor != TPM_CR50_I2C_DID_VID && vendor != TPM_TI50_I2C_DID_VID) {
> > + if (vendor != TPM_CR50_I2C_DID_VID &&
> > + vendor != TPM_TI50_DT_I2C_DID_VID &&
> > + vendor != TPM_TI50_OT_I2C_DID_VID) {
> > dev_err(dev, "Vendor ID did not match! ID was %08x\n", vendor);
> > tpm_cr50_release_locality(chip, true);
> > return -ENODEV;
> > }
> >
> > dev_info(dev, "%s TPM 2.0 (i2c 0x%02x irq %d id 0x%x)\n",
> > - vendor == TPM_TI50_I2C_DID_VID ? "ti50" : "cr50",
> > + vendor == TPM_CR50_I2C_DID_VID ? "cr50" :
> > + vendor == TPM_TI50_DT_I2C_DID_VID ? "ti50 DT" :
> > + "ti50 OT",
Whenever possible ternary operator should be avoided, unless the use
case super trivial: this complexity brings us zero measurable benefit
and unnecessarily obfuscates code.
I'd suggest to simply add a helper:
/*
* Maps VID to a name.
*/
const char *tpm_cr50_vid_to_name(u32 vendor)
{
switch (vendor) {
case TPM_CR50_I2C_DID_VID:
return "cr50";
case TPM_TI50_DT_I2C_DID_VID:
return "ti50 DT";
case TPM_TI50_OT_I2C_DID_VID:
return "ti50 OT";
default:
break;
}
tpm_cr50_release_locality(chip, true);
return NULL;
}
The code then transforms to:
vendor = le32_to_cpup((__le32 *)buf);
name = tpm2_cr50_vid_to_name(vendor);
if (name == NULL) {
dev_err(dev, "Vendor ID did not match! ID was %08x\n", vendor);
return -ENODEV;
}
dev_info(dev, "%s TPM 2.0 (i2c 0x%02x irq %d id 0x%x)\n", name.
client->addr, client->addr, client->irq, vendor >> 16);
[and add suggested-by]
> > client->addr, client->irq, vendor >> 16);
> > return tpm_chip_register(chip);
> > }
> > --
> > 2.45.2.1089.g2a221341d9-goog
> >
BR, Jarkko
