Commit 5c83b07d authored by Qunqin Zhao's avatar Qunqin Zhao Committed by Lee Jones
Browse files

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: default avatarYinggang Gu <guyinggang@loongson.cn>
Signed-off-by: default avatarYinggang Gu <guyinggang@loongson.cn>
Signed-off-by: default avatarQunqin Zhao <zhaoqunqin@loongson.cn>
Reviewed-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Link: https://lore.kernel.org/r/20250705072045.1067-4-zhaoqunqin@loongson.cn


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 766b2d72

drivers/char/tpm/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -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

drivers/char/tpm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/char/tpm/tpm_loongson.c

0 → 100644
+84 −0
Original line number Diff line number Diff line 
// 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  = "tpm_loongson",

	},

};

module_platform_driver(tpm_loongson);



MODULE_ALIAS("platform:tpm_loongson");

MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("Loongson TPM driver");