1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Renesas R-Car E-FUSE/OTP Driver
  4 *
  5 * Copyright (C) 2024 Glider bv
  6 */
  7
  8#include <linux/device.h>
  9#include <linux/export.h>
 10#include <linux/io.h>
 11#include <linux/mod_devicetable.h>
 12#include <linux/nvmem-provider.h>
 13#include <linux/platform_device.h>
 14#include <linux/pm_runtime.h>
 15#include <linux/property.h>
 16
 17struct rcar_fuse {
 18	struct nvmem_keepout keepouts[2];
 19	struct nvmem_device *nvmem;
 20	struct device *dev;
 21	void __iomem *base;
 22};
 23
 24struct rcar_fuse_data {
 25	unsigned int bank;	/* 0: PFC + E-FUSE, 1: OPT_MEM + E-FUSE */
 26	unsigned int start;	/* inclusive */
 27	unsigned int end;	/* exclusive */
 28};
 29
 30static int rcar_fuse_reg_read(void *priv, unsigned int offset, void *val,
 31			      size_t bytes)
 32{
 33	struct rcar_fuse *fuse = priv;
 34	int ret;
 35
 36	ret = pm_runtime_resume_and_get(fuse->dev);
 37	if (ret < 0)
 38		return ret;
 39
 40	__ioread32_copy(val, fuse->base + offset, bytes / 4);
 41
 42	pm_runtime_put(fuse->dev);
 43
 44	return 0;
 45}
 46
 47static int rcar_fuse_probe(struct platform_device *pdev)
 48{
 49	struct device *dev = &pdev->dev;
 50	const struct rcar_fuse_data *data = device_get_match_data(dev);
 51	struct nvmem_config config = {
 52		.dev = dev,
 53		.name = "rcar-fuse",
 54		.id = NVMEM_DEVID_NONE,
 55		.owner = THIS_MODULE,
 56		.type = NVMEM_TYPE_OTP,
 57		.read_only = true,
 58		.root_only = true,
 59		.reg_read = rcar_fuse_reg_read,
 60		.word_size = 4,
 61		.stride = 4,
 62	};
 63	struct rcar_fuse *fuse;
 64	struct resource *res;
 65	int ret;
 66
 67	ret = devm_pm_runtime_enable(dev);
 68	if (ret < 0)
 69		return ret;
 70
 71	fuse = devm_kzalloc(dev, sizeof(*fuse), GFP_KERNEL);
 72	if (!fuse)
 73		return -ENOMEM;
 74
 75	fuse->base = devm_platform_get_and_ioremap_resource(pdev, data->bank,
 76							    &res);
 77	if (IS_ERR(fuse->base))
 78		return PTR_ERR(fuse->base);
 79
 80	fuse->dev = dev;
 81	fuse->keepouts[0].start = 0;
 82	fuse->keepouts[0].end = data->start;
 83	fuse->keepouts[1].start = data->end;
 84	fuse->keepouts[1].end = resource_size(res);
 85
 86	config.keepout = fuse->keepouts;
 87	config.nkeepout = ARRAY_SIZE(fuse->keepouts);
 88	config.size = resource_size(res);
 89	config.priv = fuse;
 90
 91	fuse->nvmem = devm_nvmem_register(dev, &config);
 92	if (IS_ERR(fuse->nvmem))
 93		return dev_err_probe(dev, PTR_ERR(fuse->nvmem),
 94				     "Failed to register NVMEM device\n");
 95
 96	return 0;
 97}
 98
 99static const struct rcar_fuse_data rcar_fuse_v3u = {
100	.bank = 0,
101	.start = 0x0c0,
102	.end = 0x0e8,
103};
104
105static const struct rcar_fuse_data rcar_fuse_s4 = {
106	.bank = 0,
107	.start = 0x0c0,
108	.end = 0x14c,
109};
110
111static const struct rcar_fuse_data rcar_fuse_v4h = {
112	.bank = 1,
113	.start = 0x100,
114	.end = 0x1a0,
115};
116
117static const struct rcar_fuse_data rcar_fuse_v4m = {
118	.bank = 1,
119	.start = 0x100,
120	.end = 0x110,
121};
122
123static const struct of_device_id rcar_fuse_match[] = {
124	{ .compatible = "renesas,r8a779a0-efuse", .data = &rcar_fuse_v3u },
125	{ .compatible = "renesas,r8a779f0-efuse", .data = &rcar_fuse_s4 },
126	{ .compatible = "renesas,r8a779g0-otp", .data = &rcar_fuse_v4h },
127	{ .compatible = "renesas,r8a779h0-otp", .data = &rcar_fuse_v4m },
128	{ /* sentinel */ }
129};
130
131static struct platform_driver rcar_fuse_driver = {
132	.probe = rcar_fuse_probe,
133	.driver = {
134		.name = "rcar_fuse",
135		.of_match_table = rcar_fuse_match,
136	},
137};
138module_platform_driver(rcar_fuse_driver);
139
140MODULE_DESCRIPTION("Renesas R-Car E-FUSE/OTP driver");
141MODULE_LICENSE("GPL");
142MODULE_AUTHOR("Geert Uytterhoeven");