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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Amlogic Meson GX eFuse Driver4 *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 17static int meson_efuse_read(void *context, unsigned int offset,18 void *val, size_t bytes)19{20 struct meson_sm_firmware *fw = context;21 int ret;22 23 ret = meson_sm_call_read(fw, (u8 *)val, bytes, SM_EFUSE_READ, offset,24 bytes, 0, 0, 0);25 26 return ret < 0 ? ret : 0;27}28 29static int meson_efuse_write(void *context, unsigned int offset,30 void *val, size_t bytes)31{32 struct meson_sm_firmware *fw = context;33 int ret;34 35 ret = meson_sm_call_write(fw, (u8 *)val, bytes, SM_EFUSE_WRITE, offset,36 bytes, 0, 0, 0);37 38 return ret < 0 ? ret : 0;39}40 41static const struct of_device_id meson_efuse_match[] = {42 { .compatible = "amlogic,meson-gxbb-efuse", },43 { /* sentinel */ },44};45MODULE_DEVICE_TABLE(of, meson_efuse_match);46 47static int meson_efuse_probe(struct platform_device *pdev)48{49 struct device *dev = &pdev->dev;50 struct meson_sm_firmware *fw;51 struct nvmem_device *nvmem;52 struct nvmem_config *econfig;53 struct clk *clk;54 unsigned int size;55 struct device_node *sm_np __free(device_node) =56 of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0);57 58 if (!sm_np) {59 dev_err(&pdev->dev, "no secure-monitor node\n");60 return -ENODEV;61 }62 63 fw = meson_sm_get(sm_np);64 if (!fw)65 return -EPROBE_DEFER;66 67 clk = devm_clk_get_enabled(dev, NULL);68 if (IS_ERR(clk))69 return dev_err_probe(dev, PTR_ERR(clk), "failed to get efuse gate");70 71 if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {72 dev_err(dev, "failed to get max user");73 return -EINVAL;74 }75 76 econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);77 if (!econfig)78 return -ENOMEM;79 80 econfig->dev = dev;81 econfig->name = dev_name(dev);82 econfig->add_legacy_fixed_of_cells = true;83 econfig->stride = 1;84 econfig->word_size = 1;85 econfig->reg_read = meson_efuse_read;86 econfig->reg_write = meson_efuse_write;87 econfig->size = size;88 econfig->priv = fw;89 90 nvmem = devm_nvmem_register(&pdev->dev, econfig);91 92 return PTR_ERR_OR_ZERO(nvmem);93}94 95static struct platform_driver meson_efuse_driver = {96 .probe = meson_efuse_probe,97 .driver = {98 .name = "meson-efuse",99 .of_match_table = meson_efuse_match,100 },101};102 103module_platform_driver(meson_efuse_driver);104 105MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");106MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");107MODULE_LICENSE("GPL v2");108