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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 ([email protected])
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 <[email protected]>");
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
50static int 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_obj(struct uflash_dev);
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 void 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
137static const struct of_device_id uflash_match[] = {
138 {
139 .name = UFLASH_OBPNAME,
140 },
141 {},
142};
143
144MODULE_DEVICE_TABLE(of, uflash_match);
145
146static struct platform_driver uflash_driver = {
147 .driver = {
148 .name = DRIVER_NAME,
149 .of_match_table = uflash_match,
150 },
151 .probe = uflash_probe,
152 .remove = uflash_remove,
153};
154
155module_platform_driver(uflash_driver);