1 // SPDX-License-Identifier: GPL-2.0-only
4  * Copyright (c) 2003-2004	Joern Engel <joern@wh.fh-wedel.de>
9  *   phram=<name>,<start>,<len>[,<erasesize>]
10  * <name> may be up to 63 characters.
28 #include <linux/mtd/mtd.h>
35 	struct mtd_info mtd;  member
42 static int phram_erase(struct mtd_info *mtd, struct erase_info *instr)  in phram_erase()  argument
44 	u_char *start = mtd->priv;  in phram_erase()
46 	memset(start + instr->addr, 0xff, instr->len);  in phram_erase()
51 static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,  in phram_point()  argument
54 	*virt = mtd->priv + from;  in phram_point()
59 static int phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)  in phram_unpoint()  argument
64 static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,  in phram_read()  argument
67 	u_char *start = mtd->priv;  in phram_read()
74 static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,  in phram_write()  argument
77 	u_char *start = mtd->priv;  in phram_write()
88 	if (phram->cached)  in phram_map()
93 		return -EIO;  in phram_map()
95 	phram->mtd.priv = addr;  in phram_map()
102 	void *addr = phram->mtd.priv;  in phram_unmap()
104 	if (phram->cached) {  in phram_unmap()
117 		mtd_device_unregister(&this->mtd);  in unregister_devices()
119 		kfree(this->mtd.name);  in unregister_devices()
124 static int register_device(struct platform_device *pdev, const char *name,  in register_device()  argument
127 	struct device_node *np = pdev ? pdev->dev.of_node : NULL;  in register_device()
128 	bool cached = np ? !of_property_read_bool(np, "no-map") : false;  in register_device()
130 	int ret = -ENOMEM;  in register_device()
136 	new->cached = cached;  in register_device()
145 	new->mtd.name = name;  in register_device()
146 	new->mtd.size = len;  in register_device()
147 	new->mtd.flags = MTD_CAP_RAM;  in register_device()
148 	new->mtd._erase = phram_erase;  in register_device()
149 	new->mtd._point = phram_point;  in register_device()
150 	new->mtd._unpoint = phram_unpoint;  in register_device()
151 	new->mtd._read = phram_read;  in register_device()
152 	new->mtd._write = phram_write;  in register_device()
153 	new->mtd.owner = THIS_MODULE;  in register_device()
154 	new->mtd.type = MTD_RAM;  in register_device()
155 	new->mtd.erasesize = erasesize;  in register_device()
156 	new->mtd.writesize = 1;  in register_device()
158 	mtd_set_of_node(&new->mtd, np);  in register_device()
160 	ret = -EAGAIN;  in register_device()
161 	if (mtd_device_register(&new->mtd, NULL, 0)) {  in register_device()
169 		list_add_tail(&new->list, &phram_list);  in register_device()
190 		if (token[len - 1] == 'i') {  in parse_num64()
191 			switch (token[len - 2]) {  in parse_num64()
200 				token[len - 2] = 0;  in parse_num64()
203 				return -EINVAL;  in parse_num64()
217 	char *name;  in parse_name()  local
221 		return -ENOSPC;  in parse_name()
223 	name = kstrdup(token, GFP_KERNEL);  in parse_name()
224 	if (!name)  in parse_name()
225 		return -ENOMEM;  in parse_name()
227 	*pname = name;  in parse_name()
250  * - phram=<device>,<address>,<size>[,<erasesize>] for module case
251  * - phram.phram=<device>,<address>,<size>[,<erasesize>] for built-in case
252  * We leave 64 bytes for the device name, 20 for the address , 20 for the
263 	char *name;  in phram_setup()  local
285 	ret = parse_name(&name, token[0]);  in phram_setup()
312 		ret = -EINVAL;  in phram_setup()
319 		ret = -EINVAL;  in phram_setup()
323 	ret = register_device(NULL, name, start, len, (uint32_t)erasesize);  in phram_setup()
327 	pr_info("%s device: %#llx at %#llx for erasesize %#llx\n", name, len, start, erasesize);  in phram_setup()
331 	kfree(name);  in phram_setup()
360 		return -ENOSPC;  in phram_param_call()
368 MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>[,<erasesize>]\"");
384 		return -ENOMEM;  in phram_probe()
386 	/* mtd_set_of_node() reads name from "label" */  in phram_probe()
387 	return register_device(pdev, NULL, res->start, resource_size(res),  in phram_probe()
395 	mtd_device_unregister(&phram->mtd);  in phram_remove()
406 		.name		= "phram",
441 MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
442 MODULE_DESCRIPTION("MTD driver for physical RAM");