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 | |
51 | sm_np = of_parse_phandle(np: pdev->dev.of_node, phandle_name: "secure-monitor" , index: 0); |
52 | if (!sm_np) { |
53 | dev_err(&pdev->dev, "no secure-monitor node\n" ); |
54 | return -ENODEV; |
55 | } |
56 | |
57 | fw = meson_sm_get(firmware_node: sm_np); |
58 | of_node_put(node: sm_np); |
59 | if (!fw) |
60 | return -EPROBE_DEFER; |
61 | |
62 | clk = devm_clk_get_enabled(dev, NULL); |
63 | if (IS_ERR(ptr: clk)) |
64 | return dev_err_probe(dev, err: PTR_ERR(ptr: clk), fmt: "failed to get efuse gate" ); |
65 | |
66 | if (meson_sm_call(fw, cmd_index: SM_EFUSE_USER_MAX, ret: &size, arg0: 0, arg1: 0, arg2: 0, arg3: 0, arg4: 0) < 0) { |
67 | dev_err(dev, "failed to get max user" ); |
68 | return -EINVAL; |
69 | } |
70 | |
71 | econfig = devm_kzalloc(dev, size: sizeof(*econfig), GFP_KERNEL); |
72 | if (!econfig) |
73 | return -ENOMEM; |
74 | |
75 | econfig->dev = dev; |
76 | econfig->name = dev_name(dev); |
77 | econfig->add_legacy_fixed_of_cells = true; |
78 | econfig->stride = 1; |
79 | econfig->word_size = 1; |
80 | econfig->reg_read = meson_efuse_read; |
81 | econfig->reg_write = meson_efuse_write; |
82 | econfig->size = size; |
83 | econfig->priv = fw; |
84 | |
85 | nvmem = devm_nvmem_register(dev: &pdev->dev, cfg: econfig); |
86 | |
87 | return PTR_ERR_OR_ZERO(ptr: nvmem); |
88 | } |
89 | |
90 | static struct platform_driver meson_efuse_driver = { |
91 | .probe = meson_efuse_probe, |
92 | .driver = { |
93 | .name = "meson-efuse" , |
94 | .of_match_table = meson_efuse_match, |
95 | }, |
96 | }; |
97 | |
98 | module_platform_driver(meson_efuse_driver); |
99 | |
100 | MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>" ); |
101 | MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver" ); |
102 | MODULE_LICENSE("GPL v2" ); |
103 | |