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 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 29 static 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 41 static const struct of_device_id meson_efuse_match[] = { 42 { .compatible = "amlogic,meson-gxbb-efuse", }, 43 { /* sentinel */ }, 44 }; 45 MODULE_DEVICE_TABLE(of, meson_efuse_match); 46 47 static int meson_efuse_probe(struct platform_device *pdev) 48 { 49 struct device *dev = &pdev->dev; 50 struct meson_sm_firmware *fw; 51 struct device_node *sm_np; 52 struct nvmem_device *nvmem; 53 struct nvmem_config *econfig; 54 struct clk *clk; 55 unsigned int size; 56 57 sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0); 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 of_node_put(sm_np); 65 if (!fw) 66 return -EPROBE_DEFER; 67 68 clk = devm_clk_get_enabled(dev, NULL); 69 if (IS_ERR(clk)) 70 return dev_err_probe(dev, PTR_ERR(clk), "failed to get efuse gate"); 71 72 if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) { 73 dev_err(dev, "failed to get max user"); 74 return -EINVAL; 75 } 76 77 econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL); 78 if (!econfig) 79 return -ENOMEM; 80 81 econfig->dev = dev; 82 econfig->name = dev_name(dev); 83 econfig->add_legacy_fixed_of_cells = true; 84 econfig->stride = 1; 85 econfig->word_size = 1; 86 econfig->reg_read = meson_efuse_read; 87 econfig->reg_write = meson_efuse_write; 88 econfig->size = size; 89 econfig->priv = fw; 90 91 nvmem = devm_nvmem_register(&pdev->dev, econfig); 92 93 return PTR_ERR_OR_ZERO(nvmem); 94 } 95 96 static struct platform_driver meson_efuse_driver = { 97 .probe = meson_efuse_probe, 98 .driver = { 99 .name = "meson-efuse", 100 .of_match_table = meson_efuse_match, 101 }, 102 }; 103 104 module_platform_driver(meson_efuse_driver); 105 106 MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>"); 107 MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver"); 108 MODULE_LICENSE("GPL v2"); 109