On Thu, Jun 19, 2025 at 10:51:37AM +0800, Qunqin Zhao wrote:
> Loongson Security Engine supports random number generation, hash,
> symmetric encryption and asymmetric encryption. Based on these
> encryption functions, TPM2 have been implemented in the Loongson
> Security Engine firmware. This driver is responsible for copying data
> into the memory visible to the firmware and receiving data from the
> firmware.
>
> Co-developed-by: Yinggang Gu <guyingg...@loongson.cn>
> Signed-off-by: Yinggang Gu <guyingg...@loongson.cn>
> Signed-off-by: Qunqin Zhao <zhaoqun...@loongson.cn>
> Reviewed-by: Huacai Chen <chenhua...@loongson.cn>
> ---
> drivers/char/tpm/Kconfig | 9 ++++
> drivers/char/tpm/Makefile | 1 +
> drivers/char/tpm/tpm_loongson.c | 84 +++++++++++++++++++++++++++++++++
> 3 files changed, 94 insertions(+)
> create mode 100644 drivers/char/tpm/tpm_loongson.c
>
> diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
> index dddd702b2..ba3924eb1 100644
> --- a/drivers/char/tpm/Kconfig
> +++ b/drivers/char/tpm/Kconfig
> @@ -189,6 +189,15 @@ config TCG_IBMVTPM
> will be accessible from within Linux. To compile this driver
> as a module, choose M here; the module will be called tpm_ibmvtpm.
>
> +config TCG_LOONGSON
> + tristate "Loongson TPM Interface"
> + depends on MFD_LOONGSON_SE
> + help
> + If you want to make Loongson TPM support available, 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_loongson.
> +
> config TCG_XEN
> tristate "XEN TPM Interface"
> depends on TCG_TPM && XEN
> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> index 9de1b3ea3..5b5cdc0d3 100644
> --- a/drivers/char/tpm/Makefile
> +++ b/drivers/char/tpm/Makefile
> @@ -46,3 +46,4 @@ obj-$(CONFIG_TCG_ARM_CRB_FFA) += tpm_crb_ffa.o
> obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o
> obj-$(CONFIG_TCG_FTPM_TEE) += tpm_ftpm_tee.o
> obj-$(CONFIG_TCG_SVSM) += tpm_svsm.o
> +obj-$(CONFIG_TCG_LOONGSON) += tpm_loongson.o
> diff --git a/drivers/char/tpm/tpm_loongson.c b/drivers/char/tpm/tpm_loongson.c
> new file mode 100644
> index 000000000..5cbdb37f8
> --- /dev/null
> +++ b/drivers/char/tpm/tpm_loongson.c
> @@ -0,0 +1,84 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2025 Loongson Technology Corporation Limited. */
> +
> +#include <linux/device.h>
> +#include <linux/mfd/loongson-se.h>
> +#include <linux/platform_device.h>
> +#include <linux/wait.h>
> +
> +#include "tpm.h"
> +
> +struct tpm_loongson_cmd {
> + u32 cmd_id;
> + u32 data_off;
> + u32 data_len;
> + u32 pad[5];
> +};
> +
> +static int tpm_loongson_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> +{
> + struct loongson_se_engine *tpm_engine = dev_get_drvdata(&chip->dev);
> + struct tpm_loongson_cmd *cmd_ret = tpm_engine->command_ret;
> +
> + if (cmd_ret->data_len > count)
> + return -EIO;
> +
> + memcpy(buf, tpm_engine->data_buffer, cmd_ret->data_len);
> +
> + return cmd_ret->data_len;
> +}
> +
> +static int tpm_loongson_send(struct tpm_chip *chip, u8 *buf, size_t count)
> +{
> + struct loongson_se_engine *tpm_engine = dev_get_drvdata(&chip->dev);
> + struct tpm_loongson_cmd *cmd = tpm_engine->command;
> +
> + if (count > tpm_engine->buffer_size)
> + return -E2BIG;
> +
> + cmd->data_len = count;
> + memcpy(tpm_engine->data_buffer, buf, count);
> +
> + return loongson_se_send_engine_cmd(tpm_engine);
> +}
> +
> +static const struct tpm_class_ops tpm_loongson_ops = {
> + .flags = TPM_OPS_AUTO_STARTUP,
> + .recv = tpm_loongson_recv,
> + .send = tpm_loongson_send,
> +};
> +
> +static int tpm_loongson_probe(struct platform_device *pdev)
> +{
> + struct loongson_se_engine *tpm_engine;
> + struct device *dev = &pdev->dev;
> + struct tpm_loongson_cmd *cmd;
> + struct tpm_chip *chip;
> +
> + tpm_engine = loongson_se_init_engine(dev->parent, SE_ENGINE_TPM);
> + if (!tpm_engine)
> + return -ENODEV;
> + cmd = tpm_engine->command;
> + cmd->cmd_id = SE_CMD_TPM;
> + cmd->data_off = tpm_engine->buffer_off;
> +
> + chip = tpmm_chip_alloc(dev, &tpm_loongson_ops);
> + if (IS_ERR(chip))
> + return PTR_ERR(chip);
> + chip->flags = TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_IRQ;
> + dev_set_drvdata(&chip->dev, tpm_engine);
> +
> + return tpm_chip_register(chip);
> +}
> +
> +static struct platform_driver tpm_loongson = {
> + .probe = tpm_loongson_probe,
> + .driver = {
> + .name = "loongson-tpm",
This patch looks otherwise great but I'd prefer here tho use
"tpm_loongson_probe" for the value of the name field.
> + },
> +};
> +module_platform_driver(tpm_loongson);
> +
> +MODULE_ALIAS("platform:loongson-tpm");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Loongson TPM driver");
> --
> 2.45.2
>
BR, Jarkko
