diff mbox series

[v8,4/5] tpm: Add a driver for Loongson TPM device

Message ID 20250418093407.1335-5-zhaoqunqin@loongson.cn
State New
Headers show
Series Add Loongson Security Engine chip driver | expand

Commit Message

Qunqin Zhao April 18, 2025, 9:34 a.m. UTC 
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 <guyinggang@loongson.cn>
Signed-off-by: Yinggang Gu <guyinggang@loongson.cn>
Signed-off-by: Qunqin Zhao <zhaoqunqin@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
---
v8: In the send callback, it will wait until the TPM2 command is
    completed. So do not need to wait in the recv callback.
    Removed Jarkko's tag cause there are some changes in v8

v7: Moved Kconfig entry between TCG_IBMVTPM and TCG_XEN.
    Added Jarkko's tag(a little change, should be fine).

v6: Replace all "ls6000se" with "loongson"
    Prefix all with tpm_loongson instead of tpm_lsse.
    Removed Jarkko's tag cause there are some changes in v6

v5: None
v4: Prefix all with tpm_lsse instead of tpm.
    Removed MODULE_AUTHOR fields.

v3: Added reminder about Loongson security engine to git log.

 drivers/char/tpm/Kconfig        |  9 ++++
 drivers/char/tpm/Makefile       |  1 +
 drivers/char/tpm/tpm_loongson.c | 78 +++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+)
 create mode 100644 drivers/char/tpm/tpm_loongson.c
diff mbox series

Patch

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index fe4f3a609..34302a875 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 CRYPTO_DEV_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 2b004df8c..cb534b235 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -45,3 +45,4 @@  obj-$(CONFIG_TCG_CRB) += tpm_crb.o
 obj-$(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_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..c4d69d28d
--- /dev/null
+++ b/drivers/char/tpm/tpm_loongson.c
@@ -0,0 +1,78 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025 Loongson Technology Corporation Limited. */
+
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/wait.h>
+
+#include "../../drivers/crypto/loongson/loongson-se.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;
+
+	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;
+
+	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_driver = {
+	.probe   = tpm_loongson_probe,
+	.driver  = {
+		.name  = "loongson-tpm",
+	},
+};
+module_platform_driver(tpm_loongson_driver);
+
+MODULE_ALIAS("platform:loongson-tpm");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Loongson TPM driver");