1 /* Load firmware into Core B on a BF561
2 *
3 * Copyright 2004-2009 Analog Devices Inc.
4 * Licensed under the GPL-2 or later.
5 */
6
7 /* The Core B reset func requires code in the application that is loaded into
8 * Core B. In order to reset, the application needs to install an interrupt
9 * handler for Supplemental Interrupt 0, that sets RETI to 0xff600000 and
10 * writes bit 11 of SICB_SYSCR when bit 5 of SICA_SYSCR is 0. This causes Core
11 * B to stall when Supplemental Interrupt 0 is set, and will reset PC to
12 * 0xff600000 when COREB_SRAM_INIT is cleared.
13 */
14
15 #include <linux/device.h>
16 #include <linux/fs.h>
17 #include <linux/kernel.h>
18 #include <linux/miscdevice.h>
19 #include <linux/module.h>
20
21 #define CMD_COREB_START _IO('b', 0)
22 #define CMD_COREB_STOP _IO('b', 1)
23 #define CMD_COREB_RESET _IO('b', 2)
24
25 static long
coreb_ioctl(struct file * file,unsigned int cmd,unsigned long arg)26 coreb_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
27 {
28 int ret = 0;
29
30 switch (cmd) {
31 case CMD_COREB_START:
32 bfin_write_SYSCR(bfin_read_SYSCR() & ~0x0020);
33 break;
34 case CMD_COREB_STOP:
35 bfin_write_SYSCR(bfin_read_SYSCR() | 0x0020);
36 bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | 0x0080);
37 break;
38 case CMD_COREB_RESET:
39 bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | 0x0080);
40 break;
41 default:
42 ret = -EINVAL;
43 break;
44 }
45
46 CSYNC();
47
48 return ret;
49 }
50
51 static const struct file_operations coreb_fops = {
52 .owner = THIS_MODULE,
53 .unlocked_ioctl = coreb_ioctl,
54 .llseek = noop_llseek,
55 };
56
57 static struct miscdevice coreb_dev = {
58 .minor = MISC_DYNAMIC_MINOR,
59 .name = "coreb",
60 .fops = &coreb_fops,
61 };
62
bf561_coreb_init(void)63 static int __init bf561_coreb_init(void)
64 {
65 return misc_register(&coreb_dev);
66 }
67 module_init(bf561_coreb_init);
68
bf561_coreb_exit(void)69 static void __exit bf561_coreb_exit(void)
70 {
71 misc_deregister(&coreb_dev);
72 }
73 module_exit(bf561_coreb_exit);
74
75 MODULE_AUTHOR("Bas Vermeulen <bvermeul@blackstar.xs4all.nl>");
76 MODULE_DESCRIPTION("BF561 Core B Support");
77 MODULE_LICENSE("GPL");
78