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

   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
  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
  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 }