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 		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 
uflash_probe(struct platform_device * op)108 static 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_find_property(dp, "user", NULL))
116 		return -ENODEV;
117 
118 	return uflash_devinit(op, dp);
119 }
120 
uflash_remove(struct platform_device * op)121 static 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 
139 static const struct of_device_id uflash_match[] = {
140 	{
141 		.name = UFLASH_OBPNAME,
142 	},
143 	{},
144 };
145 
146 MODULE_DEVICE_TABLE(of, uflash_match);
147 
148 static 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 
157 module_platform_driver(uflash_driver);
158