2 * Copyright (C) 2010 Michael Neuling IBM Corporation
4 * Driver for the pseries hardware RNG for POWER7+ and above
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
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
20 #include <linux/module.h>
21 #include <linux/hw_random.h>
25 static int pseries_rng_data_read(struct hwrng
*rng
, u32
*data
)
27 if (plpar_hcall(H_RANDOM
, (unsigned long *)data
) != H_SUCCESS
) {
28 printk(KERN_ERR
"pseries rng hcall error\n");
35 * pseries_rng_get_desired_dma - Return desired DMA allocate for CMO operations
37 * This is a required function for a driver to operate in a CMO environment
38 * but this device does not make use of DMA allocations, return 0.
41 * Number of bytes of IO data the driver will need to perform well -> 0
43 static unsigned long pseries_rng_get_desired_dma(struct vio_dev
*vdev
)
48 static struct hwrng pseries_rng
= {
49 .name
= KBUILD_MODNAME
,
50 .data_read
= pseries_rng_data_read
,
53 static int __init
pseries_rng_probe(struct vio_dev
*dev
,
54 const struct vio_device_id
*id
)
56 return hwrng_register(&pseries_rng
);
59 static int __exit
pseries_rng_remove(struct vio_dev
*dev
)
61 hwrng_unregister(&pseries_rng
);
65 static struct vio_device_id pseries_rng_driver_ids
[] = {
66 { "ibm,random-v1", "ibm,random"},
69 MODULE_DEVICE_TABLE(vio
, pseries_rng_driver_ids
);
71 static struct vio_driver pseries_rng_driver
= {
72 .name
= KBUILD_MODNAME
,
73 .probe
= pseries_rng_probe
,
74 .remove
= pseries_rng_remove
,
75 .get_desired_dma
= pseries_rng_get_desired_dma
,
76 .id_table
= pseries_rng_driver_ids
79 static int __init
rng_init(void)
81 printk(KERN_INFO
"Registering IBM pSeries RNG driver\n");
82 return vio_register_driver(&pseries_rng_driver
);
85 module_init(rng_init
);
87 static void __exit
rng_exit(void)
89 vio_unregister_driver(&pseries_rng_driver
);
91 module_exit(rng_exit
);
93 MODULE_LICENSE("GPL");
94 MODULE_AUTHOR("Michael Neuling <mikey@neuling.org>");
95 MODULE_DESCRIPTION("H/W RNG driver for IBM pSeries processors");