1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SDK7786 FPGA NMI Support.
4 *
5 * Copyright (C) 2010  Paul Mundt
6 */
7#include <linux/init.h>
8#include <linux/kernel.h>
9#include <linux/string.h>
10#include <mach/fpga.h>
11
12enum {
13	NMI_MODE_MANUAL,
14	NMI_MODE_AUX,
15	NMI_MODE_MASKED,
16	NMI_MODE_ANY,
17	NMI_MODE_UNKNOWN,
18};
19
20/*
21 * Default to the manual NMI switch.
22 */
23static unsigned int __initdata nmi_mode = NMI_MODE_ANY;
24
25static int __init nmi_mode_setup(char *str)
26{
27	if (!str)
28		return 0;
29
30	if (strcmp(str, "manual") == 0)
31		nmi_mode = NMI_MODE_MANUAL;
32	else if (strcmp(str, "aux") == 0)
33		nmi_mode = NMI_MODE_AUX;
34	else if (strcmp(str, "masked") == 0)
35		nmi_mode = NMI_MODE_MASKED;
36	else if (strcmp(str, "any") == 0)
37		nmi_mode = NMI_MODE_ANY;
38	else {
39		nmi_mode = NMI_MODE_UNKNOWN;
40		pr_warn("Unknown NMI mode %s\n", str);
41	}
42
43	printk("Set NMI mode to %d\n", nmi_mode);
44	return 0;
45}
46early_param("nmi_mode", nmi_mode_setup);
47
48void __init sdk7786_nmi_init(void)
49{
50	unsigned int source, mask, tmp;
51
52	switch (nmi_mode) {
53	case NMI_MODE_MANUAL:
54		source = NMISR_MAN_NMI;
55		mask = NMIMR_MAN_NMIM;
56		break;
57	case NMI_MODE_AUX:
58		source = NMISR_AUX_NMI;
59		mask = NMIMR_AUX_NMIM;
60		break;
61	case NMI_MODE_ANY:
62		source = NMISR_MAN_NMI | NMISR_AUX_NMI;
63		mask = NMIMR_MAN_NMIM | NMIMR_AUX_NMIM;
64		break;
65	case NMI_MODE_MASKED:
66	case NMI_MODE_UNKNOWN:
67	default:
68		source = mask = 0;
69		break;
70	}
71
72	/* Set the NMI source */
73	tmp = fpga_read_reg(NMISR);
74	tmp &= ~NMISR_MASK;
75	tmp |= source;
76	fpga_write_reg(tmp, NMISR);
77
78	/* And the IRQ masking */
79	fpga_write_reg(NMIMR_MASK ^ mask, NMIMR);
80}
81