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