drivers/sh/intc/balancing.c

   1 /*
   2  * Support for hardware-managed IRQ auto-distribution.
   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 "internals.h"
  11
  12 static unsigned long dist_handle[NR_IRQS];
  13
  14 void intc_balancing_enable(unsigned int irq)
  15 {
  16         struct intc_desc_int *d = get_intc_desc(irq);
  17         unsigned long handle = dist_handle[irq];
  18         unsigned long addr;
  19
  20         if (irq_balancing_disabled(irq) || !handle)
  21                 return;
  22
  23         addr = INTC_REG(d, _INTC_ADDR_D(handle), 0);
  24         intc_reg_fns[_INTC_FN(handle)](addr, handle, 1);
  25 }
  26
  27 void intc_balancing_disable(unsigned int irq)
  28 {
  29         struct intc_desc_int *d = get_intc_desc(irq);
  30         unsigned long handle = dist_handle[irq];
  31         unsigned long addr;
  32
  33         if (irq_balancing_disabled(irq) || !handle)
  34                 return;
  35
  36         addr = INTC_REG(d, _INTC_ADDR_D(handle), 0);
  37         intc_reg_fns[_INTC_FN(handle)](addr, handle, 0);
  38 }
  39
  40 static unsigned int intc_dist_data(struct intc_desc *desc,
  41                                    struct intc_desc_int *d,
  42                                    intc_enum enum_id)
  43 {
  44         struct intc_mask_reg *mr = desc->hw.mask_regs;
  45         unsigned int i, j, fn, mode;
  46         unsigned long reg_e, reg_d;
  47
  48         for (i = 0; mr && enum_id && i < desc->hw.nr_mask_regs; i++) {
  49                 mr = desc->hw.mask_regs + i;
  50
  51                 /*
  52                  * Skip this entry if there's no auto-distribution
  53                  * register associated with it.
  54                  */
  55                 if (!mr->dist_reg)
  56                         continue;
  57
  58                 for (j = 0; j < ARRAY_SIZE(mr->enum_ids); j++) {
  59                         if (mr->enum_ids[j] != enum_id)
  60                                 continue;
  61
  62                         fn = REG_FN_MODIFY_BASE;
  63                         mode = MODE_ENABLE_REG;
  64                         reg_e = mr->dist_reg;
  65                         reg_d = mr->dist_reg;
  66
  67                         fn += (mr->reg_width >> 3) - 1;
  68                         return _INTC_MK(fn, mode,
  69                                         intc_get_reg(d, reg_e),
  70                                         intc_get_reg(d, reg_d),
  71                                         1,
  72                                         (mr->reg_width - 1) - j);
  73                 }
  74         }
  75
  76         /*
  77          * It's possible we've gotten here with no distribution options
  78          * available for the IRQ in question, so we just skip over those.
  79          */
  80         return 0;
  81 }
  82
  83 void intc_set_dist_handle(unsigned int irq, struct intc_desc *desc,
  84                           struct intc_desc_int *d, intc_enum id)
  85 {
  86         unsigned long flags;
  87
  88         /*
  89          * Nothing to do for this IRQ.
  90          */
  91         if (!desc->hw.mask_regs)
  92                 return;
  93
  94         raw_spin_lock_irqsave(&intc_big_lock, flags);
  95         dist_handle[irq] = intc_dist_data(desc, d, id);
  96         raw_spin_unlock_irqrestore(&intc_big_lock, flags);
  97 }