1// SPDX-License-Identifier: GPL-2.0-only
2/* sun_uflash.c - Driver for user-programmable flash on
3 *                Sun Microsystems SME boardsets.
4 *
5 * This driver does NOT provide access to the OBP-flash for
6 * safety reasons-- use <linux>/drivers/sbus/char/flash.c instead.
7 *
8 * Copyright (c) 2001 Eric Brower (ebrower@usa.net)
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/fs.h>
14#include <linux/errno.h>
15#include <linux/ioport.h>
16#include <linux/of.h>
17#include <linux/platform_device.h>
18#include <linux/slab.h>
19#include <asm/prom.h>
20#include <linux/uaccess.h>
21#include <asm/io.h>
22
23#include <linux/mtd/mtd.h>
24#include <linux/mtd/map.h>
25
26#define UFLASH_OBPNAME	"flashprom"
27#define DRIVER_NAME	"sun_uflash"
28#define PFX		DRIVER_NAME ": "
29
30#define UFLASH_WINDOW_SIZE	0x200000
31#define UFLASH_BUSWIDTH		1			/* EBus is 8-bit */
32
33MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
34MODULE_DESCRIPTION("User-programmable flash device on Sun Microsystems boardsets");
35MODULE_LICENSE("GPL");
36MODULE_VERSION("2.1");
37
38struct uflash_dev {
39	const char		*name;	/* device name */
40	struct map_info 	map;	/* mtd map info */
41	struct mtd_info		*mtd;	/* mtd info */
42};
43
44struct map_info uflash_map_templ = {
45	.name =		"SUNW,???-????",
46	.size =		UFLASH_WINDOW_SIZE,
47	.bankwidth =	UFLASH_BUSWIDTH,
48};
49
50int uflash_devinit(struct platform_device *op, struct device_node *dp)
51{
52	struct uflash_dev *up;
53
54	if (op->resource[1].flags) {
55		/* Non-CFI userflash device-- once I find one we
56		 * can work on supporting it.
57		 */
58		printk(KERN_ERR PFX "Unsupported device at %pOF, 0x%llx\n",
59		       dp, (unsigned long long)op->resource[0].start);
60
61		return -ENODEV;
62	}
63
64	up = kzalloc(sizeof(struct uflash_dev), GFP_KERNEL);
65	if (!up)
66		return -ENOMEM;
67
68	/* copy defaults and tweak parameters */
69	memcpy(&up->map, &uflash_map_templ, sizeof(uflash_map_templ));
70
71	up->map.size = resource_size(&op->resource[0]);
72
73	up->name = of_get_property(dp, "model", NULL);
74	if (up->name && 0 < strlen(up->name))
75		up->map.name = up->name;
76
77	up->map.phys = op->resource[0].start;
78
79	up->map.virt = of_ioremap(&op->resource[0], 0, up->map.size,
80				  DRIVER_NAME);
81	if (!up->map.virt) {
82		printk(KERN_ERR PFX "Failed to map device.\n");
83		kfree(up);
84
85		return -EINVAL;
86	}
87
88	simple_map_init(&up->map);
89
90	/* MTD registration */
91	up->mtd = do_map_probe("cfi_probe", &up->map);
92	if (!up->mtd) {
93		of_iounmap(&op->resource[0], up->map.virt, up->map.size);
94		kfree(up);
95
96		return -ENXIO;
97	}
98
99	up->mtd->owner = THIS_MODULE;
100
101	mtd_device_register(up->mtd, NULL, 0);
102
103	dev_set_drvdata(&op->dev, up);
104
105	return 0;
106}
107
108static int uflash_probe(struct platform_device *op)
109{
110	struct device_node *dp = op->dev.of_node;
111
112	/* Flashprom must have the "user" property in order to
113	 * be used by this driver.
114	 */
115	if (!of_property_read_bool(dp, "user"))
116		return -ENODEV;
117
118	return uflash_devinit(op, dp);
119}
120
121static int uflash_remove(struct platform_device *op)
122{
123	struct uflash_dev *up = dev_get_drvdata(&op->dev);
124
125	if (up->mtd) {
126		mtd_device_unregister(up->mtd);
127		map_destroy(up->mtd);
128	}
129	if (up->map.virt) {
130		of_iounmap(&op->resource[0], up->map.virt, up->map.size);
131		up->map.virt = NULL;
132	}
133
134	kfree(up);
135
136	return 0;
137}
138
139static const struct of_device_id uflash_match[] = {
140	{
141		.name = UFLASH_OBPNAME,
142	},
143	{},
144};
145
146MODULE_DEVICE_TABLE(of, uflash_match);
147
148static struct platform_driver uflash_driver = {
149	.driver = {
150		.name = DRIVER_NAME,
151		.of_match_table = uflash_match,
152	},
153	.probe		= uflash_probe,
154	.remove		= uflash_remove,
155};
156
157module_platform_driver(uflash_driver);
158