1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Amlogic Meson GX eFuse Driver |
4 | * |
5 | * Copyright (c) 2016 Endless Computers, Inc. |
6 | * Author: Carlo Caione <carlo@endlessm.com> |
7 | */ |
8 | |
9 | #include <linux/clk.h> |
10 | #include <linux/module.h> |
11 | #include <linux/nvmem-provider.h> |
12 | #include <linux/of.h> |
13 | #include <linux/platform_device.h> |
14 | |
15 | #include <linux/firmware/meson/meson_sm.h> |
16 | |
17 | static int meson_efuse_read(void *context, unsigned int offset, |
18 | void *val, size_t bytes) |
19 | { |
20 | struct meson_sm_firmware *fw = context; |
21 | |
22 | return meson_sm_call_read(fw, buffer: (u8 *)val, bsize: bytes, cmd_index: SM_EFUSE_READ, arg0: offset, |
23 | arg1: bytes, arg2: 0, arg3: 0, arg4: 0); |
24 | } |
25 | |
26 | static int meson_efuse_write(void *context, unsigned int offset, |
27 | void *val, size_t bytes) |
28 | { |
29 | struct meson_sm_firmware *fw = context; |
30 | |
31 | return meson_sm_call_write(fw, buffer: (u8 *)val, b_size: bytes, cmd_index: SM_EFUSE_WRITE, arg0: offset, |
32 | arg1: bytes, arg2: 0, arg3: 0, arg4: 0); |
33 | } |
34 | |
35 | static const struct of_device_id meson_efuse_match[] = { |
36 | { .compatible = "amlogic,meson-gxbb-efuse" , }, |
37 | { /* sentinel */ }, |
38 | }; |
39 | MODULE_DEVICE_TABLE(of, meson_efuse_match); |
40 | |
41 | static int meson_efuse_probe(struct platform_device *pdev) |
42 | { |
43 | struct device *dev = &pdev->dev; |
44 | struct meson_sm_firmware *fw; |
45 | struct device_node *sm_np; |
46 | struct nvmem_device *nvmem; |
47 | struct nvmem_config *econfig; |
48 | struct clk *clk; |
49 | unsigned int size; |
50 | int ret; |
51 | |
52 | sm_np = of_parse_phandle(np: pdev->dev.of_node, phandle_name: "secure-monitor" , index: 0); |
53 | if (!sm_np) { |
54 | dev_err(&pdev->dev, "no secure-monitor node\n" ); |
55 | return -ENODEV; |
56 | } |
57 | |
58 | fw = meson_sm_get(firmware_node: sm_np); |
59 | of_node_put(node: sm_np); |
60 | if (!fw) |
61 | return -EPROBE_DEFER; |
62 | |
63 | clk = devm_clk_get(dev, NULL); |
64 | if (IS_ERR(ptr: clk)) { |
65 | ret = PTR_ERR(ptr: clk); |
66 | if (ret != -EPROBE_DEFER) |
67 | dev_err(dev, "failed to get efuse gate" ); |
68 | return ret; |
69 | } |
70 | |
71 | ret = clk_prepare_enable(clk); |
72 | if (ret) { |
73 | dev_err(dev, "failed to enable gate" ); |
74 | return ret; |
75 | } |
76 | |
77 | ret = devm_add_action_or_reset(dev, |
78 | (void(*)(void *))clk_disable_unprepare, |
79 | clk); |
80 | if (ret) { |
81 | dev_err(dev, "failed to add disable callback" ); |
82 | return ret; |
83 | } |
84 | |
85 | if (meson_sm_call(fw, cmd_index: SM_EFUSE_USER_MAX, ret: &size, arg0: 0, arg1: 0, arg2: 0, arg3: 0, arg4: 0) < 0) { |
86 | dev_err(dev, "failed to get max user" ); |
87 | return -EINVAL; |
88 | } |
89 | |
90 | econfig = devm_kzalloc(dev, size: sizeof(*econfig), GFP_KERNEL); |
91 | if (!econfig) |
92 | return -ENOMEM; |
93 | |
94 | econfig->dev = dev; |
95 | econfig->name = dev_name(dev); |
96 | econfig->add_legacy_fixed_of_cells = true; |
97 | econfig->stride = 1; |
98 | econfig->word_size = 1; |
99 | econfig->reg_read = meson_efuse_read; |
100 | econfig->reg_write = meson_efuse_write; |
101 | econfig->size = size; |
102 | econfig->priv = fw; |
103 | |
104 | nvmem = devm_nvmem_register(dev: &pdev->dev, cfg: econfig); |
105 | |
106 | return PTR_ERR_OR_ZERO(ptr: nvmem); |
107 | } |
108 | |
109 | static struct platform_driver meson_efuse_driver = { |
110 | .probe = meson_efuse_probe, |
111 | .driver = { |
112 | .name = "meson-efuse" , |
113 | .of_match_table = meson_efuse_match, |
114 | }, |
115 | }; |
116 | |
117 | module_platform_driver(meson_efuse_driver); |
118 | |
119 | MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>" ); |
120 | MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver" ); |
121 | MODULE_LICENSE("GPL v2" ); |
122 | |