| 1 | |
| 2 | |
| 3 | * Apple SoC eFuse driver
|
| 4 | *
|
| 5 | * Copyright (C) The Asahi Linux Contributors
|
| 6 |
|
| 7 |
|
| 8 | #include <linux/io.h>
|
| 9 | #include <linux/module.h>
|
| 10 | #include <linux/nvmem-provider.h>
|
| 11 | #include <linux/platform_device.h>
|
| 12 |
|
| 13 | struct apple_efuses_priv {
|
| 14 | void __iomem *fuses;
|
| 15 | };
|
| 16 |
|
| 17 | static int apple_efuses_read(void *context, unsigned int offset, void *val,
|
| 18 | size_t bytes)
|
| 19 | {
|
| 20 | struct apple_efuses_priv *priv = context;
|
| 21 | u32 *dst = val;
|
| 22 |
|
| 23 | while (bytes >= sizeof(u32)) {
|
| 24 | *dst++ = readl_relaxed(priv->fuses + offset);
|
| 25 | bytes -= sizeof(u32);
|
| 26 | offset += sizeof(u32);
|
| 27 | }
|
| 28 |
|
| 29 | return 0;
|
| 30 | }
|
| 31 |
|
| 32 | static int apple_efuses_probe(struct platform_device *pdev)
|
| 33 | {
|
| 34 | struct apple_efuses_priv *priv;
|
| 35 | struct resource *res;
|
| 36 | struct nvmem_config config = {
|
| 37 | .dev = &pdev->dev,
|
| 38 | .add_legacy_fixed_of_cells = true,
|
| 39 | .read_only = true,
|
| 40 | .reg_read = apple_efuses_read,
|
| 41 | .stride = sizeof(u32),
|
| 42 | .word_size = sizeof(u32),
|
| 43 | .name = "apple_efuses_nvmem",
|
| 44 | .id = NVMEM_DEVID_AUTO,
|
| 45 | .root_only = true,
|
| 46 | };
|
| 47 |
|
| 48 | priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL);
|
| 49 | if (!priv)
|
| 50 | return -ENOMEM;
|
| 51 |
|
| 52 | priv->fuses = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
|
| 53 | if (IS_ERR(priv->fuses))
|
| 54 | return PTR_ERR(priv->fuses);
|
| 55 |
|
| 56 | config.priv = priv;
|
| 57 | config.size = resource_size(res);
|
| 58 |
|
| 59 | return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
|
| 60 | }
|
| 61 |
|
| 62 | static const struct of_device_id apple_efuses_of_match[] = {
|
| 63 | { .compatible = "apple,efuses", },
|
| 64 | {}
|
| 65 | };
|
| 66 |
|
| 67 | MODULE_DEVICE_TABLE(of, apple_efuses_of_match);
|
| 68 |
|
| 69 | static struct platform_driver apple_efuses_driver = {
|
| 70 | .driver = {
|
| 71 | .name = "apple_efuses",
|
| 72 | .of_match_table = apple_efuses_of_match,
|
| 73 | },
|
| 74 | .probe = apple_efuses_probe,
|
| 75 | };
|
| 76 |
|
| 77 | module_platform_driver(apple_efuses_driver);
|
| 78 |
|
| 79 | MODULE_AUTHOR("Sven Peter <[email protected]>");
|
| 80 | MODULE_DESCRIPTION("Apple SoC eFuse driver");
|
| 81 | MODULE_LICENSE("GPL");
|