xref: /openbmc/linux/drivers/mtd/maps/sun_uflash.c (revision 275876e2)
1 /* sun_uflash.c - Driver for user-programmable flash on
2  *                Sun Microsystems SME boardsets.
3  *
4  * This driver does NOT provide access to the OBP-flash for
5  * safety reasons-- use <linux>/drivers/sbus/char/flash.c instead.
6  *
7  * Copyright (c) 2001 Eric Brower (ebrower@usa.net)
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/fs.h>
13 #include <linux/errno.h>
14 #include <linux/ioport.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/slab.h>
18 #include <asm/prom.h>
19 #include <asm/uaccess.h>
20 #include <asm/io.h>
21 
22 #include <linux/mtd/mtd.h>
23 #include <linux/mtd/map.h>
24 
25 #define UFLASH_OBPNAME	"flashprom"
26 #define DRIVER_NAME	"sun_uflash"
27 #define PFX		DRIVER_NAME ": "
28 
29 #define UFLASH_WINDOW_SIZE	0x200000
30 #define UFLASH_BUSWIDTH		1			/* EBus is 8-bit */
31 
32 MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
33 MODULE_DESCRIPTION("User-programmable flash device on Sun Microsystems boardsets");
34 MODULE_SUPPORTED_DEVICE(DRIVER_NAME);
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 
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 %s, 0x%llx\n",
59 		       dp->full_name, (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 
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 
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 		.owner = THIS_MODULE,
154 		.of_match_table = uflash_match,
155 	},
156 	.probe		= uflash_probe,
157 	.remove		= uflash_remove,
158 };
159 
160 module_platform_driver(uflash_driver);
161