tpm_loongson.c

 1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright (c) 2025 Loongson Technology Corporation Limited. */
 3
 4#include <linux/device.h>
 5#include <linux/mfd/loongson-se.h>
 6#include <linux/platform_device.h>
 7#include <linux/wait.h>
 8
 9#include "tpm.h"
10
11struct tpm_loongson_cmd {
12	u32 cmd_id;
13	u32 data_off;
14	u32 data_len;
15	u32 pad[5];
16};
17
18static int tpm_loongson_recv(struct tpm_chip *chip, u8 *buf, size_t count)
19{
20	struct loongson_se_engine *tpm_engine = dev_get_drvdata(&chip->dev);
21	struct tpm_loongson_cmd *cmd_ret = tpm_engine->command_ret;
22
23	if (cmd_ret->data_len > count)
24		return -EIO;
25
26	memcpy(buf, tpm_engine->data_buffer, cmd_ret->data_len);
27
28	return cmd_ret->data_len;
29}
30
31static int tpm_loongson_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz, size_t count)
32{
33	struct loongson_se_engine *tpm_engine = dev_get_drvdata(&chip->dev);
34	struct tpm_loongson_cmd *cmd = tpm_engine->command;
35
36	if (count > tpm_engine->buffer_size)
37		return -E2BIG;
38
39	cmd->data_len = count;
40	memcpy(tpm_engine->data_buffer, buf, count);
41
42	return loongson_se_send_engine_cmd(tpm_engine);
43}
44
45static const struct tpm_class_ops tpm_loongson_ops = {
46	.flags = TPM_OPS_AUTO_STARTUP,
47	.recv = tpm_loongson_recv,
48	.send = tpm_loongson_send,
49};
50
51static int tpm_loongson_probe(struct platform_device *pdev)
52{
53	struct loongson_se_engine *tpm_engine;
54	struct device *dev = &pdev->dev;
55	struct tpm_loongson_cmd *cmd;
56	struct tpm_chip *chip;
57
58	tpm_engine = loongson_se_init_engine(dev->parent, SE_ENGINE_TPM);
59	if (!tpm_engine)
60		return -ENODEV;
61	cmd = tpm_engine->command;
62	cmd->cmd_id = SE_CMD_TPM;
63	cmd->data_off = tpm_engine->buffer_off;
64
65	chip = tpmm_chip_alloc(dev, &tpm_loongson_ops);
66	if (IS_ERR(chip))
67		return PTR_ERR(chip);
68	chip->flags = TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_IRQ;
69	dev_set_drvdata(&chip->dev, tpm_engine);
70
71	return tpm_chip_register(chip);
72}
73
74static struct platform_driver tpm_loongson = {
75	.probe   = tpm_loongson_probe,
76	.driver  = {
77		.name  = "tpm_loongson",
78	},
79};
80module_platform_driver(tpm_loongson);
81
82MODULE_ALIAS("platform:tpm_loongson");
83MODULE_LICENSE("GPL");
84MODULE_DESCRIPTION("Loongson TPM driver");