1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Amlogic Meson GX eFuse Driver
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (c) 2016 Endless Computers, Inc.
6*4882a593Smuzhiyun * Author: Carlo Caione <carlo@endlessm.com>
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/clk.h>
10*4882a593Smuzhiyun #include <linux/module.h>
11*4882a593Smuzhiyun #include <linux/nvmem-provider.h>
12*4882a593Smuzhiyun #include <linux/of.h>
13*4882a593Smuzhiyun #include <linux/platform_device.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #include <linux/firmware/meson/meson_sm.h>
16*4882a593Smuzhiyun
meson_efuse_read(void * context,unsigned int offset,void * val,size_t bytes)17*4882a593Smuzhiyun static int meson_efuse_read(void *context, unsigned int offset,
18*4882a593Smuzhiyun void *val, size_t bytes)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun struct meson_sm_firmware *fw = context;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun return meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,
23*4882a593Smuzhiyun bytes, 0, 0, 0);
24*4882a593Smuzhiyun }
25*4882a593Smuzhiyun
meson_efuse_write(void * context,unsigned int offset,void * val,size_t bytes)26*4882a593Smuzhiyun static int meson_efuse_write(void *context, unsigned int offset,
27*4882a593Smuzhiyun void *val, size_t bytes)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun struct meson_sm_firmware *fw = context;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun return meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,
32*4882a593Smuzhiyun bytes, 0, 0, 0);
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun static const struct of_device_id meson_efuse_match[] = {
36*4882a593Smuzhiyun { .compatible = "amlogic,meson-gxbb-efuse", },
37*4882a593Smuzhiyun { /* sentinel */ },
38*4882a593Smuzhiyun };
39*4882a593Smuzhiyun MODULE_DEVICE_TABLE(of, meson_efuse_match);
40*4882a593Smuzhiyun
meson_efuse_probe(struct platform_device * pdev)41*4882a593Smuzhiyun static int meson_efuse_probe(struct platform_device *pdev)
42*4882a593Smuzhiyun {
43*4882a593Smuzhiyun struct device *dev = &pdev->dev;
44*4882a593Smuzhiyun struct meson_sm_firmware *fw;
45*4882a593Smuzhiyun struct device_node *sm_np;
46*4882a593Smuzhiyun struct nvmem_device *nvmem;
47*4882a593Smuzhiyun struct nvmem_config *econfig;
48*4882a593Smuzhiyun struct clk *clk;
49*4882a593Smuzhiyun unsigned int size;
50*4882a593Smuzhiyun int ret;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);
53*4882a593Smuzhiyun if (!sm_np) {
54*4882a593Smuzhiyun dev_err(&pdev->dev, "no secure-monitor node\n");
55*4882a593Smuzhiyun return -ENODEV;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun fw = meson_sm_get(sm_np);
59*4882a593Smuzhiyun of_node_put(sm_np);
60*4882a593Smuzhiyun if (!fw)
61*4882a593Smuzhiyun return -EPROBE_DEFER;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun clk = devm_clk_get(dev, NULL);
64*4882a593Smuzhiyun if (IS_ERR(clk)) {
65*4882a593Smuzhiyun ret = PTR_ERR(clk);
66*4882a593Smuzhiyun if (ret != -EPROBE_DEFER)
67*4882a593Smuzhiyun dev_err(dev, "failed to get efuse gate");
68*4882a593Smuzhiyun return ret;
69*4882a593Smuzhiyun }
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun ret = clk_prepare_enable(clk);
72*4882a593Smuzhiyun if (ret) {
73*4882a593Smuzhiyun dev_err(dev, "failed to enable gate");
74*4882a593Smuzhiyun return ret;
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun ret = devm_add_action_or_reset(dev,
78*4882a593Smuzhiyun (void(*)(void *))clk_disable_unprepare,
79*4882a593Smuzhiyun clk);
80*4882a593Smuzhiyun if (ret) {
81*4882a593Smuzhiyun dev_err(dev, "failed to add disable callback");
82*4882a593Smuzhiyun return ret;
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
86*4882a593Smuzhiyun dev_err(dev, "failed to get max user");
87*4882a593Smuzhiyun return -EINVAL;
88*4882a593Smuzhiyun }
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
91*4882a593Smuzhiyun if (!econfig)
92*4882a593Smuzhiyun return -ENOMEM;
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun econfig->dev = dev;
95*4882a593Smuzhiyun econfig->name = dev_name(dev);
96*4882a593Smuzhiyun econfig->stride = 1;
97*4882a593Smuzhiyun econfig->word_size = 1;
98*4882a593Smuzhiyun econfig->reg_read = meson_efuse_read;
99*4882a593Smuzhiyun econfig->reg_write = meson_efuse_write;
100*4882a593Smuzhiyun econfig->size = size;
101*4882a593Smuzhiyun econfig->priv = fw;
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun nvmem = devm_nvmem_register(&pdev->dev, econfig);
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun return PTR_ERR_OR_ZERO(nvmem);
106*4882a593Smuzhiyun }
107*4882a593Smuzhiyun
108*4882a593Smuzhiyun static struct platform_driver meson_efuse_driver = {
109*4882a593Smuzhiyun .probe = meson_efuse_probe,
110*4882a593Smuzhiyun .driver = {
111*4882a593Smuzhiyun .name = "meson-efuse",
112*4882a593Smuzhiyun .of_match_table = meson_efuse_match,
113*4882a593Smuzhiyun },
114*4882a593Smuzhiyun };
115*4882a593Smuzhiyun
116*4882a593Smuzhiyun module_platform_driver(meson_efuse_driver);
117*4882a593Smuzhiyun
118*4882a593Smuzhiyun MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
119*4882a593Smuzhiyun MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
120*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
121