On 25/05/2022 18:58, Alexander Steffen wrote: > Implement the TCG I2C Interface driver, as specified in the TCG PC > Client Platform TPM Profile (PTP) specification for TPM 2.0 v1.04 > revision 14, section 8, I2C Interface Definition. > > This driver supports Guard Times. That is, if required by the TPM, the > driver has to wait by a vendor-specific time after each I2C read/write. > The specific time is read from the TPM_I2C_INTERFACE_CAPABILITY register. > > Unfortunately, the TCG specified almost but not quite compatible > register addresses. Therefore, the TIS register addresses need to be > mapped to I2C ones. The locality is stripped because for now, only > locality 0 is supported. > > Add a sanity check to I2C reads of e.g. TPM_ACCESS and TPM_STS. This is > to detect communication errors and issues due to non-standard behaviour > (E.g. the clock stretching quirk in the BCM2835, see 4dbfb5f4401f). In > case the sanity check fails, attempt a retry. > > Co-developed-by: Johannes Holland <johannes.holland@xxxxxxxxxxxx> > Signed-off-by: Johannes Holland <johannes.holland@xxxxxxxxxxxx> > Co-developed-by: Amir Mizinski <amirmizi6@xxxxxxxxx> > Signed-off-by: Amir Mizinski <amirmizi6@xxxxxxxxx> > Signed-off-by: Alexander Steffen <Alexander.Steffen@xxxxxxxxxxxx> > --- > drivers/char/tpm/Kconfig | 12 + > drivers/char/tpm/Makefile | 1 + > drivers/char/tpm/tpm_tis_i2c.c | 406 +++++++++++++++++++++++++++++++++ > 3 files changed, 419 insertions(+) > create mode 100644 drivers/char/tpm/tpm_tis_i2c.c > > diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig > index 4a5516406c22..927088b2c3d3 100644 > --- a/drivers/char/tpm/Kconfig > +++ b/drivers/char/tpm/Kconfig > @@ -74,6 +74,18 @@ config TCG_TIS_SPI_CR50 > If you have a H1 secure module running Cr50 firmware on SPI bus, > say Yes and it will be accessible from within Linux. > > +config TCG_TIS_I2C > + tristate "TPM Interface Specification 1.3 Interface / TPM 2.0 FIFO Interface - (I2C - generic)" > + depends on I2C > + select CRC_CCITT > + select TCG_TIS_CORE > + help > + If you have a TPM security chip, compliant with the TCG TPM PTP > + (I2C interface) specification and connected to an I2C bus master, > + say Yes and it will be accessible from within Linux. > + To compile this driver as a module, choose M here; > + the module will be called tpm_tis_i2c. > + > config TCG_TIS_SYNQUACER > tristate "TPM Interface Specification 1.2 Interface / TPM 2.0 FIFO Interface (MMIO - SynQuacer)" > depends on ARCH_SYNQUACER || COMPILE_TEST > diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile > index 66d39ea6bd10..0222b1ddb310 100644 > --- a/drivers/char/tpm/Makefile > +++ b/drivers/char/tpm/Makefile > @@ -29,6 +29,7 @@ tpm_tis_spi-$(CONFIG_TCG_TIS_SPI_CR50) += tpm_tis_spi_cr50.o > > obj-$(CONFIG_TCG_TIS_I2C_CR50) += tpm_tis_i2c_cr50.o > > +obj-$(CONFIG_TCG_TIS_I2C) += tpm_tis_i2c.o > obj-$(CONFIG_TCG_TIS_I2C_ATMEL) += tpm_i2c_atmel.o > obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o > obj-$(CONFIG_TCG_TIS_I2C_NUVOTON) += tpm_i2c_nuvoton.o > diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c > new file mode 100644 > index 000000000000..8b9218e5405f > --- /dev/null > +++ b/drivers/char/tpm/tpm_tis_i2c.c > @@ -0,0 +1,406 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2014-2021 Nuvoton Technology corporation > + * Copyright (C) 2019-2022 Infineon Technologies AG > + * > + * This device driver implements the TPM interface as defined in the TCG PC > + * Client Platform TPM Profile (PTP) Specification for TPM 2.0 v1.04 > + * Revision 14. > + * > + * It is based on the tpm_tis_spi device driver. > + */ > + > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/slab.h> > +#include <linux/interrupt.h> Is it used? > +#include <linux/wait.h> > +#include <linux/acpi.h> Is it used? > +#include <linux/freezer.h> Is it used? > + > +#include <linux/module.h> > +#include <linux/i2c.h> > +#include <linux/gpio.h> > +#include <linux/of_irq.h> > +#include <linux/of_gpio.h> The same for these three. Best regards, Krzysztof
