arch/ppc/syslib/ppc8xx_pic.c

   1 #include <linux/module.h>
   2 #include <linux/stddef.h>
   3 #include <linux/init.h>
   4 #include <linux/sched.h>
   5 #include <linux/signal.h>
   6 #include <linux/interrupt.h>
   7 #include <asm/irq.h>
   8 #include <asm/io.h>
   9 #include <asm/8xx_immap.h>
  10 #include <asm/mpc8xx.h>
  11 #include "ppc8xx_pic.h"
  12
  13 extern int cpm_get_irq(void);
  14
  15 /* The 8xx internal interrupt controller.  It is usually
  16  * the only interrupt controller.  Some boards, like the MBX and
  17  * Sandpoint have the 8259 as a secondary controller.  Depending
  18  * upon the processor type, the internal controller can have as
  19  * few as 16 interrups or as many as 64.  We could use  the
  20  * "clear_bit()" and "set_bit()" functions like other platforms,
  21  * but they are overkill for us.
  22  */
  23
  24 static void m8xx_mask_irq(unsigned int irq_nr)
  25 {
  26         int     bit, word;
  27
  28         bit = irq_nr & 0x1f;
  29         word = irq_nr >> 5;
  30
  31         ppc_cached_irq_mask[word] &= ~(1 << (31-bit));
  32         out_be32(&((immap_t *)IMAP_ADDR)->im_siu_conf.sc_simask, ppc_cached_irq_mask[word]);
  33 }
  34
  35 static void m8xx_unmask_irq(unsigned int irq_nr)
  36 {
  37         int     bit, word;
  38
  39         bit = irq_nr & 0x1f;
  40         word = irq_nr >> 5;
  41
  42         ppc_cached_irq_mask[word] |= (1 << (31-bit));
  43         out_be32(&((immap_t *)IMAP_ADDR)->im_siu_conf.sc_simask, ppc_cached_irq_mask[word]);
  44 }
  45
  46 static void m8xx_end_irq(unsigned int irq_nr)
  47 {
  48         if (!(irq_desc[irq_nr].status & (IRQ_DISABLED|IRQ_INPROGRESS))
  49                         && irq_desc[irq_nr].action) {
  50                 int bit, word;
  51
  52                 bit = irq_nr & 0x1f;
  53                 word = irq_nr >> 5;
  54
  55                 ppc_cached_irq_mask[word] |= (1 << (31-bit));
  56                 out_be32(&((immap_t *)IMAP_ADDR)->im_siu_conf.sc_simask, ppc_cached_irq_mask[word]);
  57         }
  58 }
  59
  60
  61 static void m8xx_mask_and_ack(unsigned int irq_nr)
  62 {
  63         int     bit, word;
  64
  65         bit = irq_nr & 0x1f;
  66         word = irq_nr >> 5;
  67
  68         ppc_cached_irq_mask[word] &= ~(1 << (31-bit));
  69         out_be32(&((immap_t *)IMAP_ADDR)->im_siu_conf.sc_simask, ppc_cached_irq_mask[word]);
  70         out_be32(&((immap_t *)IMAP_ADDR)->im_siu_conf.sc_sipend, 1 << (31-bit));
  71 }
  72
  73 struct hw_interrupt_type ppc8xx_pic = {
  74         .typename = " 8xx SIU  ",
  75         .enable = m8xx_unmask_irq,
  76         .disable = m8xx_mask_irq,
  77         .ack = m8xx_mask_and_ack,
  78         .end = m8xx_end_irq,
  79 };
  80
  81 /*
  82  * We either return a valid interrupt or -1 if there is nothing pending
  83  */
  84 int
  85 m8xx_get_irq(struct pt_regs *regs)
  86 {
  87         int irq;
  88
  89         /* For MPC8xx, read the SIVEC register and shift the bits down
  90          * to get the irq number.
  91          */
  92         irq = in_be32(&((immap_t *)IMAP_ADDR)->im_siu_conf.sc_sivec) >> 26;
  93
  94         /*
  95          * When we read the sivec without an interrupt to process, we will
  96          * get back SIU_LEVEL7.  In this case, return -1
  97          */
  98         if (irq == CPM_INTERRUPT)
  99                 irq = CPM_IRQ_OFFSET + cpm_get_irq();
 100 #if defined(CONFIG_PCI)
 101         else if (irq == ISA_BRIDGE_INT) {
 102                 int isa_irq;
 103
 104                 if ((isa_irq = i8259_poll(regs)) >= 0)
 105                         irq = I8259_IRQ_OFFSET + isa_irq;
 106         }
 107 #endif  /* CONFIG_PCI */
 108         else if (irq == SIU_LEVEL7)
 109                 irq = -1;
 110
 111         return irq;
 112 }
 113
 114 #if defined(CONFIG_MBX) && defined(CONFIG_PCI)
 115 /* Only the MBX uses the external 8259.  This allows us to catch standard
 116  * drivers that may mess up the internal interrupt controllers, and also
 117  * allow them to run without modification on the MBX.
 118  */
 119 void mbx_i8259_action(int irq, void *dev_id, struct pt_regs *regs)
 120 {
 121         /* This interrupt handler never actually gets called.  It is
 122          * installed only to unmask the 8259 cascade interrupt in the SIU
 123          * and to make the 8259 cascade interrupt visible in /proc/interrupts.
 124          */
 125 }
 126 #endif  /* CONFIG_PCI */