1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
4 */
5
6#include <linux/firmware/qcom/qcom_scm.h>
7#include <linux/mod_devicetable.h>
8#include <linux/nvmem-provider.h>
9#include <linux/platform_device.h>
10#include <linux/pm_runtime.h>
11
12/**
13 * struct sec_qfprom - structure holding secure qfprom attributes
14 *
15 * @base: starting physical address for secure qfprom corrected address space.
16 * @dev: qfprom device structure.
17 */
18struct sec_qfprom {
19	phys_addr_t base;
20	struct device *dev;
21};
22
23static int sec_qfprom_reg_read(void *context, unsigned int reg, void *_val, size_t bytes)
24{
25	struct sec_qfprom *priv = context;
26	unsigned int i;
27	u8 *val = _val;
28	u32 read_val;
29	u8 *tmp;
30
31	for (i = 0; i < bytes; i++, reg++) {
32		if (i == 0 || reg % 4 == 0) {
33			if (qcom_scm_io_readl(priv->base + (reg & ~3), &read_val)) {
34				dev_err(priv->dev, "Couldn't access fuse register\n");
35				return -EINVAL;
36			}
37			tmp = (u8 *)&read_val;
38		}
39
40		val[i] = tmp[reg & 3];
41	}
42
43	return 0;
44}
45
46static int sec_qfprom_probe(struct platform_device *pdev)
47{
48	struct nvmem_config econfig = {
49		.name = "sec-qfprom",
50		.stride = 1,
51		.word_size = 1,
52		.id = NVMEM_DEVID_AUTO,
53		.reg_read = sec_qfprom_reg_read,
54	};
55	struct device *dev = &pdev->dev;
56	struct nvmem_device *nvmem;
57	struct sec_qfprom *priv;
58	struct resource *res;
59
60	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
61	if (!priv)
62		return -ENOMEM;
63
64	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
65	if (!res)
66		return -EINVAL;
67
68	priv->base = res->start;
69
70	econfig.size = resource_size(res);
71	econfig.dev = dev;
72	econfig.priv = priv;
73
74	priv->dev = dev;
75
76	nvmem = devm_nvmem_register(dev, &econfig);
77
78	return PTR_ERR_OR_ZERO(nvmem);
79}
80
81static const struct of_device_id sec_qfprom_of_match[] = {
82	{ .compatible = "qcom,sec-qfprom" },
83	{/* sentinel */},
84};
85MODULE_DEVICE_TABLE(of, sec_qfprom_of_match);
86
87static struct platform_driver qfprom_driver = {
88	.probe = sec_qfprom_probe,
89	.driver = {
90		.name = "qcom_sec_qfprom",
91		.of_match_table = sec_qfprom_of_match,
92	},
93};
94module_platform_driver(qfprom_driver);
95MODULE_DESCRIPTION("Qualcomm Secure QFPROM driver");
96MODULE_LICENSE("GPL");
97