On Fri, Jul 17, 2020 at 05:49:31PM +0900, Masahisa Kojima wrote:
> When fitted, the SynQuacer platform exposes its SPI TPM via a MMIO
> window that is backed by the SPI command sequencer in the SPI bus
> controller. This arrangement has the limitation that only byte size
> accesses are supported, and so we'll need to provide a separate module
> that take this into account.
>
> Signed-off-by: Ard Biesheuvel <[email protected]>
> Signed-off-by: Masahisa Kojima <[email protected]>
> ---
> drivers/char/tpm/Kconfig | 12 ++
> drivers/char/tpm/Makefile | 1 +
> drivers/char/tpm/tpm_tis_synquacer.c | 209 +++++++++++++++++++++++++++
> 3 files changed, 222 insertions(+)
> create mode 100644 drivers/char/tpm/tpm_tis_synquacer.c
>
> diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
> index 58b4c573d176..a18c314da211 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_SYNQUACER
> + tristate "TPM Interface Specification 1.2 Interface / TPM 2.0 FIFO
> Interface (MMIO - SynQuacer)"
> + depends on ARCH_SYNQUACER
> + select TCG_TIS_CORE
> + help
> + If you have a TPM security chip that is compliant with the
> + TCG TIS 1.2 TPM specification (TPM1.2) or the TCG PTP FIFO
> + specification (TPM2.0) say Yes and it will be accessible from
> + within Linux on Socionext SynQuacer platform.
> + To compile this driver as a module, choose M here;
> + the module will be called tpm_tis_synquacer.
> +
> config TCG_TIS_I2C_ATMEL
> tristate "TPM Interface Specification 1.2 Interface (I2C - Atmel)"
> depends on I2C
> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> index 9567e5197f74..84db4fb3a9c9 100644
> --- a/drivers/char/tpm/Makefile
> +++ b/drivers/char/tpm/Makefile
> @@ -21,6 +21,7 @@ tpm-$(CONFIG_EFI) += eventlog/efi.o
> tpm-$(CONFIG_OF) += eventlog/of.o
> obj-$(CONFIG_TCG_TIS_CORE) += tpm_tis_core.o
> obj-$(CONFIG_TCG_TIS) += tpm_tis.o
> +obj-$(CONFIG_TCG_TIS_SYNQUACER) += tpm_tis_synquacer.o
>
> obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.o
> tpm_tis_spi-y := tpm_tis_spi_main.o
> diff --git a/drivers/char/tpm/tpm_tis_synquacer.c
> b/drivers/char/tpm/tpm_tis_synquacer.c
> new file mode 100644
> index 000000000000..ac2a1d2a5001
> --- /dev/null
> +++ b/drivers/char/tpm/tpm_tis_synquacer.c
> @@ -0,0 +1,209 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020 Linaro Ltd.
> + *
> + * This device driver implements MMIO TPM on SynQuacer Platform.
> + */
> +#include <linux/acpi.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/kernel.h>
> +#include "tpm.h"
> +#include "tpm_tis_core.h"
> +
> +struct tpm_tis_synquacer_info {
> + struct resource res;
> + /* irq > 0 means: use irq $irq;
> + * irq = 0 means: autoprobe for an irq;
> + * irq = -1 means: no irq support
> + */
> + int irq;
> +};
According to the coding style, multi-line comments must begin with an
empty line.
Also it would be preferable to have the comment prepending the struct
for easier read:
/*
* irq > 0 means: use irq $irq;
* irq = 0 means: autoprobe for an irq;
* irq = -1 means: no irq support
*/
struct tpm_tis_synquacer_info {
> +
> +struct tpm_tis_synquacer_phy {
> + struct tpm_tis_data priv;
> + void __iomem *iobase;
> +};
> +
> +static inline struct tpm_tis_synquacer_phy *to_tpm_tis_tcg_phy(struct
> tpm_tis_data *data)
> +{
> + return container_of(data, struct tpm_tis_synquacer_phy, priv);
> +}
> +
> +static int tpm_tis_synquacer_read_bytes(struct tpm_tis_data *data, u32 addr,
> + u16 len, u8 *result)
> +{
> + struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
> +
> + while (len--)
> + *result++ = ioread8(phy->iobase + addr);
> +
> + return 0;
> +}
> +
> +static int tpm_tis_synquacer_write_bytes(struct tpm_tis_data *data, u32 addr,
> + u16 len, const u8 *value)
> +{
> + struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
> +
> + while (len--)
> + iowrite8(*value++, phy->iobase + addr);
> +
> + return 0;
> +}
> +
> +static int tpm_tis_synquacer_read16_bw(struct tpm_tis_data *data,
> + u32 addr, u16 *result)
> +{
> + struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
> +
> + /*
> + * Due to the limitation of SPI controller on SynQuacer,
> + * 16/32 bits access must be done in byte-wise and descending order.
> + */
> + *result = (ioread8(phy->iobase + addr + 1) << 8) |
> + (ioread8(phy->iobase + addr));
> +
> + return 0;
> +}
> +
> +static int tpm_tis_synquacer_read32_bw(struct tpm_tis_data *data,
> + u32 addr, u32 *result)
> +{
> + struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
> +
> + /*
> + * Due to the limitation of SPI controller on SynQuacer,
> + * 16/32 bits access must be done in byte-wise and descending order.
> + */
> + *result = (ioread8(phy->iobase + addr + 3) << 24) |
> + (ioread8(phy->iobase + addr + 2) << 16) |
> + (ioread8(phy->iobase + addr + 1) << 8) |
> + (ioread8(phy->iobase + addr));
> +
> + return 0;
> +}
> +
> +static int tpm_tis_synquacer_write32_bw(struct tpm_tis_data *data,
> + u32 addr, u32 value)
> +{
> + struct tpm_tis_synquacer_phy *phy = to_tpm_tis_tcg_phy(data);
> +
> + /*
> + * Due to the limitation of SPI controller on SynQuacer,
> + * 16/32 bits access must be done in byte-wise and descending order.
> + */
> + iowrite8(value >> 24, phy->iobase + addr + 3);
> + iowrite8(value >> 16, phy->iobase + addr + 2);
> + iowrite8(value >> 8, phy->iobase + addr + 1);
> + iowrite8(value, phy->iobase + addr);
> +
> + return 0;
> +}
> +
> +static const struct tpm_tis_phy_ops tpm_tcg_bw = {
> + .read_bytes = tpm_tis_synquacer_read_bytes,
> + .write_bytes = tpm_tis_synquacer_write_bytes,
> + .read16 = tpm_tis_synquacer_read16_bw,
> + .read32 = tpm_tis_synquacer_read32_bw,
> + .write32 = tpm_tis_synquacer_write32_bw,
> +};
> +
> +static int tpm_tis_synquacer_init(struct device *dev,
> + struct tpm_tis_synquacer_info *tpm_info)
> +{
> + struct tpm_tis_synquacer_phy *phy;
> +
> + phy = devm_kzalloc(dev, sizeof(struct tpm_tis_synquacer_phy),
> GFP_KERNEL);
> + if (phy == NULL)
> + return -ENOMEM;
> +
> + phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
> + if (IS_ERR(phy->iobase))
> + return PTR_ERR(phy->iobase);
> +
> + return tpm_tis_core_init(dev, &phy->priv, tpm_info->irq, &tpm_tcg_bw,
> + ACPI_HANDLE(dev));
> +}
> +
> +static SIMPLE_DEV_PM_OPS(tpm_tis_synquacer_pm, tpm_pm_suspend,
> tpm_tis_resume);
> +
> +static int tpm_tis_synquacer_probe(struct platform_device *pdev)
> +{
> + struct tpm_tis_synquacer_info tpm_info = {};
> + struct resource *res;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (res == NULL) {
> + dev_err(&pdev->dev, "no memory resource defined\n");
> + return -ENODEV;
> + }
> + tpm_info.res = *res;
> +
> + tpm_info.irq = -1;
> +
> + return tpm_tis_synquacer_init(&pdev->dev, &tpm_info);
> +}
> +
> +static int tpm_tis_synquacer_remove(struct platform_device *pdev)
> +{
> + struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
> +
> + tpm_chip_unregister(chip);
> + tpm_tis_remove(chip);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id tis_synquacer_of_platform_match[] = {
> + {.compatible = "socionext,synquacer-tpm-mmio"},
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, tis_synquacer_of_platform_match);
> +#endif
> +
> +#ifdef CONFIG_ACPI
> +static const struct acpi_device_id tpm_synquacer_acpi_tbl[] = {
> + { "SCX0009" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(acpi, tpm_synquacer_acpi_tbl);
> +#endif
> +
> +static struct platform_driver tis_synquacer_drv = {
> + .probe = tpm_tis_synquacer_probe,
> + .remove = tpm_tis_synquacer_remove,
> + .driver = {
> + .name = "tpm_tis_synquacer",
> + .pm = &tpm_tis_synquacer_pm,
> + .of_match_table = of_match_ptr(tis_synquacer_of_platform_match),
> + .acpi_match_table = ACPI_PTR(tpm_synquacer_acpi_tbl),
> + },
> +};
> +
> +static int __init tpm_tis_synquacer_module_init(void)
> +{
> + int rc;
> +
> + rc = platform_driver_register(&tis_synquacer_drv);
> + if (rc)
> + return rc;
> +
> + return 0;
> +}
> +
> +static void __exit tpm_tis_synquacer_module_exit(void)
> +{
> + platform_driver_unregister(&tis_synquacer_drv);
> +}
> +
> +module_init(tpm_tis_synquacer_module_init);
> +module_exit(tpm_tis_synquacer_module_exit);
> +MODULE_AUTHOR("Masahisa Kojima ([email protected])");
It is completely redundant field because authorship is part of the
commit object itself. And it does not tell the truth after a while
anyway. MODULE_AUTHOR() made more sense before there was any sort of
legit versio control in place.
I think it would be better not to have it as we don't have any use
for this data. It is just cruft hanging there.
> +MODULE_DESCRIPTION("TPM MMIO Driver for Socionext SynQuacer platform");
> +MODULE_VERSION("2.0");
> +MODULE_LICENSE("GPL");
> --
> 2.20.1
>
/Jarkko
