arch/sh/boards/mach-sdk7786/nmi.c

   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
  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
  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 }