// SPDX-License-Identifier: GPL-2.0-only /* * Amlogic Meson GX eFuse Driver * * Copyright (c) 2016 Endless Computers, Inc. * Author: Carlo Caione <carlo@endlessm.com> */ #include <linux/clk.h> #include <linux/module.h> #include <linux/nvmem-provider.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/firmware/meson/meson_sm.h> static int meson_efuse_read(void *context, unsigned int offset, void *val, size_t bytes) { return meson_sm_call_read((u8 *)val, bytes, SM_EFUSE_READ, offset, bytes, 0, 0, 0); } static int meson_efuse_write(void *context, unsigned int offset, void *val, size_t bytes) { return meson_sm_call_write((u8 *)val, bytes, SM_EFUSE_WRITE, offset, bytes, 0, 0, 0); } static const struct of_device_id meson_efuse_match[] = { { .compatible = "amlogic,meson-gxbb-efuse", }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, meson_efuse_match); static int meson_efuse_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct nvmem_device *nvmem; struct nvmem_config *econfig; struct clk *clk; unsigned int size; int ret; clk = devm_clk_get(dev, NULL); if (IS_ERR(clk)) { ret = PTR_ERR(clk); if (ret != -EPROBE_DEFER) dev_err(dev, "failed to get efuse gate"); return ret; } ret = clk_prepare_enable(clk); if (ret) { dev_err(dev, "failed to enable gate"); return ret; } ret = devm_add_action_or_reset(dev, (void(*)(void *))clk_disable_unprepare, clk); if (ret) { dev_err(dev, "failed to add disable callback"); return ret; } if (meson_sm_call(SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) { dev_err(dev, "failed to get max user"); return -EINVAL; } econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL); if (!econfig) return -ENOMEM; econfig->dev = dev; econfig->name = dev_name(dev); econfig->stride = 1; econfig->word_size = 1; econfig->reg_read = meson_efuse_read; econfig->reg_write = meson_efuse_write; econfig->size = size; nvmem = devm_nvmem_register(&pdev->dev, econfig); return PTR_ERR_OR_ZERO(nvmem); } static struct platform_driver meson_efuse_driver = { .probe = meson_efuse_probe, .driver = { .name = "meson-efuse", .of_match_table = meson_efuse_match, }, }; module_platform_driver(meson_efuse_driver); MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>"); MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver"); MODULE_LICENSE("GPL v2");