[PATCH 2/6 v4] tpm2: Add a TPMv2 MMIO TIS driver

[Simon Glass]

Hi Ilias,

On Wed, 3 Nov 2021 at 09:09, Ilias Apalodimas
<ilias.apalodimas at linaro.org> wrote:
>
> Add support for devices that expose a TPMv2 though MMIO.
> Apart from those devices, we can use the driver in our QEMU setups and
> test TPM related code which is difficult to achieve using the sandbox
> driver (e.g test the EFI TCG2 protocol).
>
> It's worth noting that a previous patch added TPMv2 TIS core functions,
> which the current driver is consuming.
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> ---
>  drivers/tpm/Kconfig         |   9 +++
>  drivers/tpm/Makefile        |   1 +
>  drivers/tpm/tpm2_tis_mmio.c | 152 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 162 insertions(+)
>  create mode 100644 drivers/tpm/tpm2_tis_mmio.c
>
> diff --git a/drivers/tpm/Kconfig b/drivers/tpm/Kconfig
> index 9eebab5cfd90..406ee8716e1e 100644
> --- a/drivers/tpm/Kconfig
> +++ b/drivers/tpm/Kconfig
> @@ -161,6 +161,15 @@ config TPM2_FTPM_TEE
>         help
>           This driver supports firmware TPM running in TEE.
>
> +config TPM2_MMIO
> +       bool "MMIO based TPM2 Interface"
> +       depends on TPM_V2
> +       help
> +         This driver supports firmware TPM2.0 MMIO interface.
> +         The usual TPM operations and the 'tpm' command can be used to talk
> +         to the device using the standard TPM Interface Specification (TIS)
> +         protocol.
> +
>  endif # TPM_V2
>
>  endmenu
> diff --git a/drivers/tpm/Makefile b/drivers/tpm/Makefile
> index c65be5267002..494aa5a46d30 100644
> --- a/drivers/tpm/Makefile
> +++ b/drivers/tpm/Makefile
> @@ -14,3 +14,4 @@ obj-$(CONFIG_$(SPL_TPL_)TPM2_CR50_I2C) += cr50_i2c.o
>  obj-$(CONFIG_TPM2_TIS_SANDBOX) += tpm2_tis_sandbox.o sandbox_common.o
>  obj-$(CONFIG_TPM2_TIS_SPI) += tpm2_tis_spi.o
>  obj-$(CONFIG_TPM2_FTPM_TEE) += tpm2_ftpm_tee.o
> +obj-$(CONFIG_TPM2_MMIO) += tpm2_tis_core.o tpm2_tis_mmio.o
> diff --git a/drivers/tpm/tpm2_tis_mmio.c b/drivers/tpm/tpm2_tis_mmio.c
> new file mode 100644
> index 000000000000..3bd0b0871a83
> --- /dev/null
> +++ b/drivers/tpm/tpm2_tis_mmio.c
> @@ -0,0 +1,152 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * driver for mmio TCG/TIS TPM (trusted platform module).
> + *
> + * Specifications at www.trustedcomputinggroup.org
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <log.h>
> +#include <tpm-v2.h>
> +#include <linux/bitops.h>
> +#include <linux/compiler.h>
> +#include <linux/delay.h>
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +#include <linux/io.h>
> +#include <linux/unaligned/be_byteshift.h>
> +#include "tpm_tis.h"
> +#include "tpm_internal.h"
> +
> +/**
> + * struct tpm_tis_chip_data - Information about an MMIO TPM
> + * @pcr_count:          Number of PCR per bank
> + * @pcr_select_min:    Minimum size in bytes of the pcrSelect array
> + * @iobase:            Base address
> + */
> +struct tpm_tis_chip_data {
> +       unsigned int pcr_count;
> +       unsigned int pcr_select_min;
> +       void __iomem *iobase;
> +};
> +
> +static int mmio_read_bytes(struct udevice *udev, u32 addr, u16 len,

dev again

> +                          u8 *result)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +
> +       while (len--)
> +               *result++ = ioread8(drv_data->iobase + addr);
> +       return 0;
> +}
> +
> +static int mmio_write_bytes(struct udevice *udev, u32 addr, u16 len,
> +                           const u8 *value)
> +{
> +       struct tpm_tis_chip_data *drv_data = (void *)dev_get_driver_data(udev);
> +
> +       while (len--)
> +               iowrite8(*value++, drv_data->iobase + addr);

So should this use regmap?

> +       return 0;
> +}
[..]

Regards,
Simon