1/*
2 * SDK7786 FPGA NMI Support.
3 *
4 * Copyright (C) 2010  Paul Mundt
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License.  See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10#include <linux/init.h>
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <mach/fpga.h>
14
15enum {
16	NMI_MODE_MANUAL,
17	NMI_MODE_AUX,
18	NMI_MODE_MASKED,
19	NMI_MODE_ANY,
20	NMI_MODE_UNKNOWN,
21};
22
23/*
24 * Default to the manual NMI switch.
25 */
26static unsigned int __initdata nmi_mode = NMI_MODE_ANY;
27
28static int __init nmi_mode_setup(char *str)
29{
30	if (!str)
31		return 0;
32
33	if (strcmp(str, "manual") == 0)
34		nmi_mode = NMI_MODE_MANUAL;
35	else if (strcmp(str, "aux") == 0)
36		nmi_mode = NMI_MODE_AUX;
37	else if (strcmp(str, "masked") == 0)
38		nmi_mode = NMI_MODE_MASKED;
39	else if (strcmp(str, "any") == 0)
40		nmi_mode = NMI_MODE_ANY;
41	else {
42		nmi_mode = NMI_MODE_UNKNOWN;
43		pr_warning("Unknown NMI mode %s\n", str);
44	}
45
46	printk("Set NMI mode to %d\n", nmi_mode);
47	return 0;
48}
49early_param("nmi_mode", nmi_mode_setup);
50
51void __init sdk7786_nmi_init(void)
52{
53	unsigned int source, mask, tmp;
54
55	switch (nmi_mode) {
56	case NMI_MODE_MANUAL:
57		source = NMISR_MAN_NMI;
58		mask = NMIMR_MAN_NMIM;
59		break;
60	case NMI_MODE_AUX:
61		source = NMISR_AUX_NMI;
62		mask = NMIMR_AUX_NMIM;
63		break;
64	case NMI_MODE_ANY:
65		source = NMISR_MAN_NMI | NMISR_AUX_NMI;
66		mask = NMIMR_MAN_NMIM | NMIMR_AUX_NMIM;
67		break;
68	case NMI_MODE_MASKED:
69	case NMI_MODE_UNKNOWN:
70	default:
71		source = mask = 0;
72		break;
73	}
74
75	/* Set the NMI source */
76	tmp = fpga_read_reg(NMISR);
77	tmp &= ~NMISR_MASK;
78	tmp |= source;
79	fpga_write_reg(tmp, NMISR);
80
81	/* And the IRQ masking */
82	fpga_write_reg(NMIMR_MASK ^ mask, NMIMR);
83}
84