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(addr: priv->base + (reg & ~3), val: &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 .add_legacy_fixed_of_cells = true,
51 .stride = 1,
52 .word_size = 1,
53 .id = NVMEM_DEVID_AUTO,
54 .reg_read = sec_qfprom_reg_read,
55 };
56 struct device *dev = &pdev->dev;
57 struct nvmem_device *nvmem;
58 struct sec_qfprom *priv;
59 struct resource *res;
60
61 priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL);
62 if (!priv)
63 return -ENOMEM;
64
65 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
66 if (!res)
67 return -EINVAL;
68
69 priv->base = res->start;
70
71 econfig.size = resource_size(res);
72 econfig.dev = dev;
73 econfig.priv = priv;
74
75 priv->dev = dev;
76
77 nvmem = devm_nvmem_register(dev, cfg: &econfig);
78
79 return PTR_ERR_OR_ZERO(ptr: nvmem);
80}
81
82static const struct of_device_id sec_qfprom_of_match[] = {
83 { .compatible = "qcom,sec-qfprom" },
84 {/* sentinel */},
85};
86MODULE_DEVICE_TABLE(of, sec_qfprom_of_match);
87
88static struct platform_driver qfprom_driver = {
89 .probe = sec_qfprom_probe,
90 .driver = {
91 .name = "qcom_sec_qfprom",
92 .of_match_table = sec_qfprom_of_match,
93 },
94};
95module_platform_driver(qfprom_driver);
96MODULE_DESCRIPTION("Qualcomm Secure QFPROM driver");
97MODULE_LICENSE("GPL");
98

source code of linux/drivers/nvmem/sec-qfprom.c