xref: /openbmc/linux/arch/sh/boards/mach-sdk7786/nmi.c (revision 6d80f20c)
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 
12 enum {
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  */
23 static unsigned int __initdata nmi_mode = NMI_MODE_ANY;
24 
nmi_mode_setup(char * str)25 static 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 }
46 early_param("nmi_mode", nmi_mode_setup);
47 
sdk7786_nmi_init(void)48 void __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