release/src-rt-6.x.4708/linux/linux-2.6.36/arch/xtensa/variants/s6000/irq.c

   1 /*
   2  * s6000 irq crossbar
   3  *
   4  * Copyright (c) 2009 emlix GmbH
   5  * Authors:     Johannes Weiner <jw@emlix.com>
   6  *              Oskar Schirmer <os@emlix.com>
   7  */
   8 #include <linux/io.h>
   9 #include <asm/irq.h>
  10 #include <variant/hardware.h>
  11
  12 /* S6_REG_INTC */
  13 #define INTC_STATUS     0x000
  14 #define INTC_RAW        0x010
  15 #define INTC_STATUS_AG  0x100
  16 #define INTC_CFG(n)     (0x200 + 4 * (n))
  17
  18 /*
  19  * The s6000 has a crossbar that multiplexes interrupt output lines
  20  * from the peripherals to input lines on the xtensa core.
  21  *
  22  * We leave the mapping decisions to the platform as it depends on the
  23  * actually connected peripherals which distribution makes sense.
  24  */
  25 extern const signed char *platform_irq_mappings[NR_IRQS];
  26
  27 static unsigned long scp_to_intc_enable[] = {
  28 #define TO_INTC_ENABLE(n)       (((n) << 1) + 1)
  29         TO_INTC_ENABLE(0),
  30         TO_INTC_ENABLE(1),
  31         TO_INTC_ENABLE(2),
  32         TO_INTC_ENABLE(3),
  33         TO_INTC_ENABLE(4),
  34         TO_INTC_ENABLE(5),
  35         TO_INTC_ENABLE(6),
  36         TO_INTC_ENABLE(7),
  37         TO_INTC_ENABLE(8),
  38         TO_INTC_ENABLE(9),
  39         TO_INTC_ENABLE(10),
  40         TO_INTC_ENABLE(11),
  41         TO_INTC_ENABLE(12),
  42         -1,
  43         -1,
  44         TO_INTC_ENABLE(13),
  45         -1,
  46         TO_INTC_ENABLE(14),
  47         -1,
  48         TO_INTC_ENABLE(15),
  49 #undef  TO_INTC_ENABLE
  50 };
  51
  52 static void irq_set(unsigned int irq, int enable)
  53 {
  54         unsigned long en;
  55         const signed char *m = platform_irq_mappings[irq];
  56
  57         if (!m)
  58                 return;
  59         en = enable ? scp_to_intc_enable[irq] : 0;
  60         while (*m >= 0) {
  61                 writel(en, S6_REG_INTC + INTC_CFG(*m));
  62                 m++;
  63         }
  64 }
  65
  66 void variant_irq_enable(unsigned int irq)
  67 {
  68         irq_set(irq, 1);
  69 }
  70
  71 void variant_irq_disable(unsigned int irq)
  72 {
  73         irq_set(irq, 0);
  74 }