diff mbox series

[v4,5/6] tpm: Add a driver for Loongson TPM device

Message ID 20250226030550.15973-1-zhaoqunqin@loongson.cn
State New
Headers show
Series None | expand

Commit Message

Qunqin Zhao Feb. 26, 2025, 3:05 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>
---
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_lsse.c | 103 ++++++++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+)
 create mode 100644 drivers/char/tpm/tpm_lsse.c
diff mbox series

Patch

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index 0fc9a510e0..56d0417065 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -225,5 +225,14 @@  config TCG_FTPM_TEE
 	help
 	  This driver proxies for firmware TPM running in TEE.
 
+config TCG_LSSE
+	tristate "Loongson TPM Interface"
+	depends on MFD_LS6000SE
+	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_lsse.
+
 source "drivers/char/tpm/st33zp24/Kconfig"
 endif # TCG_TPM
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 9bb142c752..bf2280352d 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -44,3 +44,4 @@  obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o
 obj-$(CONFIG_TCG_CRB) += tpm_crb.o
 obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o
 obj-$(CONFIG_TCG_FTPM_TEE) += tpm_ftpm_tee.o
+obj-$(CONFIG_TCG_LSSE) += tpm_lsse.o
diff --git a/drivers/char/tpm/tpm_lsse.c b/drivers/char/tpm/tpm_lsse.c
new file mode 100644
index 0000000000..b476309c97
--- /dev/null
+++ b/drivers/char/tpm/tpm_lsse.c
@@ -0,0 +1,103 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025 Loongson Technology Corporation Limited. */
+
+#include <linux/device.h>
+#include <linux/mfd/ls6000se.h>
+#include <linux/platform_device.h>
+#include <linux/wait.h>
+
+#include "tpm.h"
+
+struct tpm_lsse_msg {
+	u32 cmd;
+	u32 data_off;
+	u32 data_len;
+	u32 info[5];
+};
+
+struct tpm_lsse_dev {
+	struct lsse_ch *se_ch;
+	struct completion tpm_lsse_completion;
+};
+
+static void tpm_lsse_complete(struct lsse_ch *ch)
+{
+	struct tpm_lsse_dev *td = ch->priv;
+
+	complete(&td->tpm_lsse_completion);
+}
+
+static int tpm_lsse_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct tpm_lsse_dev *td = dev_get_drvdata(&chip->dev);
+	struct tpm_lsse_msg *rmsg;
+	int sig;
+
+	sig = wait_for_completion_interruptible(&td->tpm_lsse_completion);
+	if (sig)
+		return sig;
+
+	rmsg = td->se_ch->rmsg;
+	memcpy(buf, td->se_ch->data_buffer, rmsg->data_len);
+
+	return rmsg->data_len;
+}
+
+static int tpm_lsse_send(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+	struct tpm_lsse_dev *td = dev_get_drvdata(&chip->dev);
+	struct tpm_lsse_msg *smsg = td->se_ch->smsg;
+
+	memcpy(td->se_ch->data_buffer, buf, count);
+	smsg->data_len = count;
+
+	return se_send_ch_requeset(td->se_ch);
+}
+
+static const struct tpm_class_ops tpm_lsse_ops = {
+	.flags = TPM_OPS_AUTO_STARTUP,
+	.recv = tpm_lsse_recv,
+	.send = tpm_lsse_send,
+};
+
+static int tpm_lsse_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct tpm_lsse_msg *smsg;
+	struct tpm_lsse_dev *td;
+	struct tpm_chip *chip;
+
+	td = devm_kzalloc(dev, sizeof(struct tpm_lsse_dev), GFP_KERNEL);
+	if (!td)
+		return -ENOMEM;
+
+	init_completion(&td->tpm_lsse_completion);
+	td->se_ch = se_init_ch(dev->parent, SE_CH_TPM, PAGE_SIZE,
+			       2 * sizeof(struct tpm_lsse_msg), td,
+			       tpm_lsse_complete);
+	if (!td->se_ch)
+		return -ENODEV;
+	smsg = td->se_ch->smsg;
+	smsg->cmd = SE_CMD_TPM;
+	smsg->data_off = td->se_ch->off;
+
+	chip = tpmm_chip_alloc(dev, &tpm_lsse_ops);
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	chip->flags = TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_IRQ;
+	dev_set_drvdata(&chip->dev, td);
+
+	return tpm_chip_register(chip);
+}
+
+static struct platform_driver tpm_lsse_driver = {
+	.probe   = tpm_lsse_probe,
+	.driver  = {
+		.name  = "ls6000se-tpm",
+	},
+};
+module_platform_driver(tpm_lsse_driver);
+
+MODULE_ALIAS("platform:ls6000se-tpm");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Loongson TPM driver");