Re: [RFC 1/1] hw: tpmtisspi: add SPI support to QEMU TPM implementation

[Stefan Berger]

On 8/3/22 04:52, Cédric Le Goater wrote:
> On 8/3/22 04:32, Iris Chen wrote:
> > From: Iris Chen <irischenlj@fb.com>

> > +++ b/hw/tpm/tpm_tis_spi.c
> > @@ -0,0 +1,311 @@
> > +#include "qemu/osdep.h"
> > +#include "hw/qdev-properties.h"
> > +#include "migration/vmstate.h"
> > +#include "hw/acpi/tpm.h"
> > +#include "tpm_prop.h"
> > +#include "tpm_tis.h"
> > +#include "qom/object.h"
> > +#include "hw/ssi/ssi.h"
> > +#include "hw/ssi/spi_gpio.h"
> > +
> > +#define TPM_TIS_SPI_ADDR_BYTES 3
> > +#define SPI_WRITE 0
> > +
> > +typedef enum {
> > +    TIS_SPI_PKT_STATE_DEACTIVATED = 0,
> > +    TIS_SPI_PKT_STATE_START,
> > +    TIS_SPI_PKT_STATE_ADDRESS,
> > +    TIS_SPI_PKT_STATE_DATA_WR,
> > +    TIS_SPI_PKT_STATE_DATA_RD,
> > +    TIS_SPI_PKT_STATE_DONE,
> > +} TpmTisSpiPktState;
> > +
> > +union TpmTisRWSizeByte {
> > +    uint8_t byte;
> > +    struct {
> > +        uint8_t data_expected_size:6;
> > +        uint8_t resv:1;
> > +        uint8_t rwflag:1;
> > +    };

I think it would be better to define a mask for the number of bytes and 
a flag for read/write rather than using bitfields. It should better for 
portability.

   Stefan