1 /* 2 * Amlogic Meson GX eFuse Driver 3 * 4 * Copyright (c) 2016 Endless Computers, Inc. 5 * Author: Carlo Caione <carlo@endlessm.com> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of version 2 of the GNU General Public License as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 */ 16 17 #include <linux/module.h> 18 #include <linux/nvmem-provider.h> 19 #include <linux/of.h> 20 #include <linux/platform_device.h> 21 22 #include <linux/firmware/meson/meson_sm.h> 23 24 static int meson_efuse_read(void *context, unsigned int offset, 25 void *val, size_t bytes) 26 { 27 return meson_sm_call_read((u8 *)val, bytes, SM_EFUSE_READ, offset, 28 bytes, 0, 0, 0); 29 } 30 31 static int meson_efuse_write(void *context, unsigned int offset, 32 void *val, size_t bytes) 33 { 34 return meson_sm_call_write((u8 *)val, bytes, SM_EFUSE_WRITE, offset, 35 bytes, 0, 0, 0); 36 } 37 38 static const struct of_device_id meson_efuse_match[] = { 39 { .compatible = "amlogic,meson-gxbb-efuse", }, 40 { /* sentinel */ }, 41 }; 42 MODULE_DEVICE_TABLE(of, meson_efuse_match); 43 44 static int meson_efuse_probe(struct platform_device *pdev) 45 { 46 struct device *dev = &pdev->dev; 47 struct nvmem_device *nvmem; 48 struct nvmem_config *econfig; 49 unsigned int size; 50 51 if (meson_sm_call(SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) 52 return -EINVAL; 53 54 econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL); 55 if (!econfig) 56 return -ENOMEM; 57 58 econfig->dev = dev; 59 econfig->name = dev_name(dev); 60 econfig->stride = 1; 61 econfig->word_size = 1; 62 econfig->reg_read = meson_efuse_read; 63 econfig->reg_write = meson_efuse_write; 64 econfig->size = size; 65 66 nvmem = devm_nvmem_register(&pdev->dev, econfig); 67 68 return PTR_ERR_OR_ZERO(nvmem); 69 } 70 71 static struct platform_driver meson_efuse_driver = { 72 .probe = meson_efuse_probe, 73 .driver = { 74 .name = "meson-efuse", 75 .of_match_table = meson_efuse_match, 76 }, 77 }; 78 79 module_platform_driver(meson_efuse_driver); 80 81 MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>"); 82 MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver"); 83 MODULE_LICENSE("GPL v2"); 84