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/of_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
33 MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
34 MODULE_DESCRIPTION("User-programmable flash device on Sun Microsystems boardsets");
35 MODULE_LICENSE("GPL");
36 MODULE_VERSION("2.1");
37
38 struct 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
44 struct map_info uflash_map_templ = {
45 .name = "SUNW,???-????",
46 .size = UFLASH_WINDOW_SIZE,
47 .bankwidth = UFLASH_BUSWIDTH,
48 };
49
uflash_devinit(struct platform_device * op,struct device_node * dp)50 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(sizeof(struct uflash_dev), GFP_KERNEL);
65 if (!up) {
66 printk(KERN_ERR PFX "Cannot allocate struct uflash_dev\n");
67 return -ENOMEM;
68 }
69
70 /* copy defaults and tweak parameters */
71 memcpy(&up->map, &uflash_map_templ, sizeof(uflash_map_templ));
72
73 up->map.size = resource_size(&op->resource[0]);
74
75 up->name = of_get_property(dp, "model", NULL);
76 if (up->name && 0 < strlen(up->name))
77 up->map.name = up->name;
78
79 up->map.phys = op->resource[0].start;
80
81 up->map.virt = of_ioremap(&op->resource[0], 0, up->map.size,
82 DRIVER_NAME);
83 if (!up->map.virt) {
84 printk(KERN_ERR PFX "Failed to map device.\n");
85 kfree(up);
86
87 return -EINVAL;
88 }
89
90 simple_map_init(&up->map);
91
92 /* MTD registration */
93 up->mtd = do_map_probe("cfi_probe", &up->map);
94 if (!up->mtd) {
95 of_iounmap(&op->resource[0], up->map.virt, up->map.size);
96 kfree(up);
97
98 return -ENXIO;
99 }
100
101 up->mtd->owner = THIS_MODULE;
102
103 mtd_device_register(up->mtd, NULL, 0);
104
105 dev_set_drvdata(&op->dev, up);
106
107 return 0;
108 }
109
uflash_probe(struct platform_device * op)110 static int uflash_probe(struct platform_device *op)
111 {
112 struct device_node *dp = op->dev.of_node;
113
114 /* Flashprom must have the "user" property in order to
115 * be used by this driver.
116 */
117 if (!of_find_property(dp, "user", NULL))
118 return -ENODEV;
119
120 return uflash_devinit(op, dp);
121 }
122
uflash_remove(struct platform_device * op)123 static int uflash_remove(struct platform_device *op)
124 {
125 struct uflash_dev *up = dev_get_drvdata(&op->dev);
126
127 if (up->mtd) {
128 mtd_device_unregister(up->mtd);
129 map_destroy(up->mtd);
130 }
131 if (up->map.virt) {
132 of_iounmap(&op->resource[0], up->map.virt, up->map.size);
133 up->map.virt = NULL;
134 }
135
136 kfree(up);
137
138 return 0;
139 }
140
141 static const struct of_device_id uflash_match[] = {
142 {
143 .name = UFLASH_OBPNAME,
144 },
145 {},
146 };
147
148 MODULE_DEVICE_TABLE(of, uflash_match);
149
150 static struct platform_driver uflash_driver = {
151 .driver = {
152 .name = DRIVER_NAME,
153 .of_match_table = uflash_match,
154 },
155 .probe = uflash_probe,
156 .remove = uflash_remove,
157 };
158
159 module_platform_driver(uflash_driver);
160