1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * i.MX9 OCOTP fusebox driver
  4 *
  5 * Copyright 2023 NXP
  6 */
  7
  8#include <linux/device.h>
  9#include <linux/io.h>
 10#include <linux/module.h>
 11#include <linux/nvmem-provider.h>
 12#include <linux/of.h>
 13#include <linux/platform_device.h>
 14#include <linux/slab.h>
 15
 16enum fuse_type {
 17	FUSE_FSB = BIT(0),
 18	FUSE_ELE = BIT(1),
 19	FUSE_ECC = BIT(2),
 20	FUSE_INVALID = -1
 21};
 22
 23struct ocotp_map_entry {
 24	u32 start; /* start word */
 25	u32 num; /* num words */
 26	enum fuse_type type;
 27};
 28
 29struct ocotp_devtype_data {
 30	u32 reg_off;
 31	char *name;
 32	u32 size;
 33	u32 num_entry;
 34	u32 flag;
 35	nvmem_reg_read_t reg_read;
 36	struct ocotp_map_entry entry[];
 37};
 38
 39struct imx_ocotp_priv {
 40	struct device *dev;
 41	void __iomem *base;
 42	struct nvmem_config config;
 43	struct mutex lock;
 44	const struct ocotp_devtype_data *data;
 45};
 46
 47static enum fuse_type imx_ocotp_fuse_type(void *context, u32 index)
 48{
 49	struct imx_ocotp_priv *priv = context;
 50	const struct ocotp_devtype_data *data = priv->data;
 51	u32 start, end;
 52	int i;
 53
 54	for (i = 0; i < data->num_entry; i++) {
 55		start = data->entry[i].start;
 56		end = data->entry[i].start + data->entry[i].num;
 57
 58		if (index >= start && index < end)
 59			return data->entry[i].type;
 60	}
 61
 62	return FUSE_INVALID;
 63}
 64
 65static int imx_ocotp_reg_read(void *context, unsigned int offset, void *val, size_t bytes)
 66{
 67	struct imx_ocotp_priv *priv = context;
 68	void __iomem *reg = priv->base + priv->data->reg_off;
 69	u32 count, index, num_bytes;
 70	enum fuse_type type;
 71	u32 *buf;
 72	void *p;
 73	int i;
 74	u8 skipbytes;
 75
 76	if (offset + bytes > priv->data->size)
 77		bytes = priv->data->size - offset;
 78
 79	index = offset >> 2;
 80	skipbytes = offset - (index << 2);
 81	num_bytes = round_up(bytes + skipbytes, 4);
 82	count = num_bytes >> 2;
 83
 84	p = kzalloc(num_bytes, GFP_KERNEL);
 85	if (!p)
 86		return -ENOMEM;
 87
 88	mutex_lock(&priv->lock);
 89
 90	buf = p;
 91
 92	for (i = index; i < (index + count); i++) {
 93		type = imx_ocotp_fuse_type(context, i);
 94		if (type == FUSE_INVALID || type == FUSE_ELE) {
 95			*buf++ = 0;
 96			continue;
 97		}
 98
 99		if (type & FUSE_ECC)
100			*buf++ = readl_relaxed(reg + (i << 2)) & GENMASK(15, 0);
101		else
102			*buf++ = readl_relaxed(reg + (i << 2));
103	}
104
105	memcpy(val, ((u8 *)p) + skipbytes, bytes);
106
107	mutex_unlock(&priv->lock);
108
109	kfree(p);
110
111	return 0;
112};
113
114static int imx_ocotp_cell_pp(void *context, const char *id, int index,
115			     unsigned int offset, void *data, size_t bytes)
116{
117	u8 *buf = data;
118	int i;
119
120	/* Deal with some post processing of nvmem cell data */
121	if (id && !strcmp(id, "mac-address"))
122		for (i = 0; i < bytes / 2; i++)
123			swap(buf[i], buf[bytes - i - 1]);
124
125	return 0;
126}
127
128static void imx_ocotp_fixup_dt_cell_info(struct nvmem_device *nvmem,
129					 struct nvmem_cell_info *cell)
130{
131	cell->read_post_process = imx_ocotp_cell_pp;
132}
133
134static int imx_ele_ocotp_probe(struct platform_device *pdev)
135{
136	struct device *dev = &pdev->dev;
137	struct imx_ocotp_priv *priv;
138	struct nvmem_device *nvmem;
139
140	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
141	if (!priv)
142		return -ENOMEM;
143
144	priv->data = of_device_get_match_data(dev);
145
146	priv->base = devm_platform_ioremap_resource(pdev, 0);
147	if (IS_ERR(priv->base))
148		return PTR_ERR(priv->base);
149
150	priv->config.dev = dev;
151	priv->config.name = "ELE-OCOTP";
152	priv->config.id = NVMEM_DEVID_AUTO;
153	priv->config.owner = THIS_MODULE;
154	priv->config.size = priv->data->size;
155	priv->config.reg_read = priv->data->reg_read;
156	priv->config.word_size = 1;
157	priv->config.stride = 1;
158	priv->config.priv = priv;
159	priv->config.read_only = true;
160	priv->config.add_legacy_fixed_of_cells = true;
161	priv->config.fixup_dt_cell_info = imx_ocotp_fixup_dt_cell_info;
162	mutex_init(&priv->lock);
163
164	nvmem = devm_nvmem_register(dev, &priv->config);
165	if (IS_ERR(nvmem))
166		return PTR_ERR(nvmem);
167
168	return 0;
169}
170
171static const struct ocotp_devtype_data imx93_ocotp_data = {
172	.reg_off = 0x8000,
173	.reg_read = imx_ocotp_reg_read,
174	.size = 2048,
175	.num_entry = 6,
176	.entry = {
177		{ 0, 52, FUSE_FSB },
178		{ 63, 1, FUSE_ELE},
179		{ 128, 16, FUSE_ELE },
180		{ 182, 1, FUSE_ELE },
181		{ 188, 1, FUSE_ELE },
182		{ 312, 200, FUSE_FSB }
183	},
184};
185
186static const struct ocotp_devtype_data imx95_ocotp_data = {
187	.reg_off = 0x8000,
188	.reg_read = imx_ocotp_reg_read,
189	.size = 2048,
190	.num_entry = 12,
191	.entry = {
192		{ 0, 1, FUSE_FSB | FUSE_ECC },
193		{ 7, 1, FUSE_FSB | FUSE_ECC },
194		{ 9, 3, FUSE_FSB | FUSE_ECC },
195		{ 12, 24, FUSE_FSB },
196		{ 36, 2, FUSE_FSB  | FUSE_ECC },
197		{ 38, 14, FUSE_FSB },
198		{ 63, 1, FUSE_ELE },
199		{ 128, 16, FUSE_ELE },
200		{ 188, 1, FUSE_ELE },
201		{ 317, 2, FUSE_FSB | FUSE_ECC },
202		{ 320, 7, FUSE_FSB },
203		{ 328, 184, FUSE_FSB }
204	},
205};
206
207static const struct of_device_id imx_ele_ocotp_dt_ids[] = {
208	{ .compatible = "fsl,imx93-ocotp", .data = &imx93_ocotp_data, },
209	{ .compatible = "fsl,imx95-ocotp", .data = &imx95_ocotp_data, },
210	{},
211};
212MODULE_DEVICE_TABLE(of, imx_ele_ocotp_dt_ids);
213
214static struct platform_driver imx_ele_ocotp_driver = {
215	.driver = {
216		.name = "imx_ele_ocotp",
217		.of_match_table = imx_ele_ocotp_dt_ids,
218	},
219	.probe = imx_ele_ocotp_probe,
220};
221module_platform_driver(imx_ele_ocotp_driver);
222
223MODULE_DESCRIPTION("i.MX OCOTP/ELE driver");
224MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
225MODULE_LICENSE("GPL");