2 * NV-RAM memory access on autcpu12
3 * (C) 2002 Thomas Gleixner (gleixner@autronix.de)
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/err.h>
20 #include <linux/sizes.h>
22 #include <linux/types.h>
23 #include <linux/kernel.h>
24 #include <linux/init.h>
25 #include <linux/device.h>
26 #include <linux/module.h>
27 #include <linux/platform_device.h>
29 #include <linux/mtd/mtd.h>
30 #include <linux/mtd/map.h>
32 struct autcpu12_nvram_priv
{
37 static int autcpu12_nvram_probe(struct platform_device
*pdev
)
39 map_word tmp
, save0
, save1
;
41 struct autcpu12_nvram_priv
*priv
;
43 priv
= devm_kzalloc(&pdev
->dev
,
44 sizeof(struct autcpu12_nvram_priv
), GFP_KERNEL
);
48 platform_set_drvdata(pdev
, priv
);
50 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
52 dev_err(&pdev
->dev
, "failed to get memory resource\n");
56 priv
->map
.bankwidth
= 4;
57 priv
->map
.phys
= res
->start
;
58 priv
->map
.size
= resource_size(res
);
59 priv
->map
.virt
= devm_ioremap_resource(&pdev
->dev
, res
);
60 strcpy((char *)priv
->map
.name
, res
->name
);
61 if (IS_ERR(priv
->map
.virt
))
62 return PTR_ERR(priv
->map
.virt
);
64 simple_map_init(&priv
->map
);
70 * Write complement to ofs 0x100000
71 * Read and check result on ofs 0x0
74 save0
= map_read(&priv
->map
, 0);
75 save1
= map_read(&priv
->map
, 0x10000);
76 tmp
.x
[0] = ~save0
.x
[0];
77 map_write(&priv
->map
, tmp
, 0x10000);
78 tmp
= map_read(&priv
->map
, 0);
79 /* if we find this pattern on 0x0, we have 32K size */
80 if (!map_word_equal(&priv
->map
, tmp
, save0
)) {
81 map_write(&priv
->map
, save0
, 0x0);
82 priv
->map
.size
= SZ_32K
;
84 map_write(&priv
->map
, save1
, 0x10000);
86 priv
->mtd
= do_map_probe("map_ram", &priv
->map
);
88 dev_err(&pdev
->dev
, "probing failed\n");
92 priv
->mtd
->owner
= THIS_MODULE
;
93 priv
->mtd
->erasesize
= 16;
94 priv
->mtd
->dev
.parent
= &pdev
->dev
;
95 if (!mtd_device_register(priv
->mtd
, NULL
, 0)) {
97 "NV-RAM device size %ldKiB registered on AUTCPU12\n",
98 priv
->map
.size
/ SZ_1K
);
102 map_destroy(priv
->mtd
);
103 dev_err(&pdev
->dev
, "NV-RAM device addition failed\n");
107 static int autcpu12_nvram_remove(struct platform_device
*pdev
)
109 struct autcpu12_nvram_priv
*priv
= platform_get_drvdata(pdev
);
111 mtd_device_unregister(priv
->mtd
);
112 map_destroy(priv
->mtd
);
117 static struct platform_driver autcpu12_nvram_driver
= {
119 .name
= "autcpu12_nvram",
120 .owner
= THIS_MODULE
,
122 .probe
= autcpu12_nvram_probe
,
123 .remove
= autcpu12_nvram_remove
,
125 module_platform_driver(autcpu12_nvram_driver
);
127 MODULE_AUTHOR("Thomas Gleixner");
128 MODULE_DESCRIPTION("autcpu12 NVRAM map driver");
129 MODULE_LICENSE("GPL");