From 5c83b07df9c5a6e063328c5b885de79f8e8f0263 Mon Sep 17 00:00:00 2001 From: Qunqin Zhao Date: Sat, 5 Jul 2025 15:20:44 +0800 Subject: [PATCH] tpm: Add a driver for Loongson TPM device 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 Signed-off-by: Yinggang Gu Signed-off-by: Qunqin Zhao Reviewed-by: Huacai Chen Reviewed-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20250705072045.1067-4-zhaoqunqin@loongson.cn Signed-off-by: Lee Jones --- 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 dddd702b2454a..ba3924eb13ba8 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 9de1b3ea34a9f..5b5cdc0d32e4e 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 0000000000000..a4ec23639911c --- /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 +#include +#include +#include + +#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 = "tpm_loongson", + }, +}; +module_platform_driver(tpm_loongson); + +MODULE_ALIAS("platform:tpm_loongson"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Loongson TPM driver"); -- 2.47.3