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 
15 enum {
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  */
26 static unsigned int __initdata nmi_mode = NMI_MODE_ANY;
27 
nmi_mode_setup(char * str)28 static 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 }
49 early_param("nmi_mode", nmi_mode_setup);
50 
sdk7786_nmi_init(void)51 void __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