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, (u8 *)val, bytes, SM_EFUSE_READ, offset, 23 bytes, 0, 0, 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, (u8 *)val, bytes, SM_EFUSE_WRITE, offset, 32 bytes, 0, 0, 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(pdev->dev.of_node, "secure-monitor", 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(sm_np); 58 of_node_put(sm_np); 59 if (!fw) 60 return -EPROBE_DEFER; 61 62 clk = devm_clk_get_enabled(dev, NULL); 63 if (IS_ERR(clk)) 64 return dev_err_probe(dev, PTR_ERR(clk), "failed to get efuse gate"); 65 66 if (meson_sm_call(fw, SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) { 67 dev_err(dev, "failed to get max user"); 68 return -EINVAL; 69 } 70 71 econfig = devm_kzalloc(dev, 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(&pdev->dev, econfig); 86 87 return PTR_ERR_OR_ZERO(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