arch/mips/pmcs-msp71xx/msp_irq_per.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2010 PMC-Sierra, Inc, derived from irq_cpu.c
   4  *
   5  * This file define the irq handler for MSP PER subsystem interrupts.
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/kernel.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/bitops.h>
  13
  14 #include <asm/mipsregs.h>
  15
  16 #include <msp_cic_int.h>
  17 #include <msp_regs.h>
  18
  19
  20 /*
  21  * Convenience Macro.  Should be somewhere generic.
  22  */
  23 #define get_current_vpe()       \
  24         ((read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) & TCBIND_CURVPE)
  25
  26 #ifdef CONFIG_SMP
  27 /*
  28  * The PER registers must be protected from concurrent access.
  29  */
  30
  31 static DEFINE_SPINLOCK(per_lock);
  32 #endif
  33
  34 /* ensure writes to per are completed */
  35
  36 static inline void per_wmb(void)
  37 {
  38         const volatile void __iomem *per_mem = PER_INT_MSK_REG;
  39         volatile u32 dummy_read;
  40
  41         wmb();
  42         dummy_read = __raw_readl(per_mem);
  43         dummy_read++;
  44 }
  45
  46 static inline void unmask_per_irq(struct irq_data *d)
  47 {
  48 #ifdef CONFIG_SMP
  49         unsigned long flags;
  50         spin_lock_irqsave(&per_lock, flags);
  51         *PER_INT_MSK_REG |= (1 << (d->irq - MSP_PER_INTBASE));
  52         spin_unlock_irqrestore(&per_lock, flags);
  53 #else
  54         *PER_INT_MSK_REG |= (1 << (d->irq - MSP_PER_INTBASE));
  55 #endif
  56         per_wmb();
  57 }
  58
  59 static inline void mask_per_irq(struct irq_data *d)
  60 {
  61 #ifdef CONFIG_SMP
  62         unsigned long flags;
  63         spin_lock_irqsave(&per_lock, flags);
  64         *PER_INT_MSK_REG &= ~(1 << (d->irq - MSP_PER_INTBASE));
  65         spin_unlock_irqrestore(&per_lock, flags);
  66 #else
  67         *PER_INT_MSK_REG &= ~(1 << (d->irq - MSP_PER_INTBASE));
  68 #endif
  69         per_wmb();
  70 }
  71
  72 static inline void msp_per_irq_ack(struct irq_data *d)
  73 {
  74         mask_per_irq(d);
  75         /*
  76          * In the PER interrupt controller, only bits 11 and 10
  77          * are write-to-clear, (SPI TX complete, SPI RX complete).
  78          * It does nothing for any others.
  79          */
  80         *PER_INT_STS_REG = (1 << (d->irq - MSP_PER_INTBASE));
  81 }
  82
  83 #ifdef CONFIG_SMP
  84 static int msp_per_irq_set_affinity(struct irq_data *d,
  85                                     const struct cpumask *affinity, bool force)
  86 {
  87         /* WTF is this doing ????? */
  88         unmask_per_irq(d);
  89         return 0;
  90 }
  91 #endif
  92
  93 static struct irq_chip msp_per_irq_controller = {
  94         .name = "MSP_PER",
  95         .irq_enable = unmask_per_irq,
  96         .irq_disable = mask_per_irq,
  97         .irq_ack = msp_per_irq_ack,
  98 #ifdef CONFIG_SMP
  99         .irq_set_affinity = msp_per_irq_set_affinity,
 100 #endif
 101 };
 102
 103 void __init msp_per_irq_init(void)
 104 {
 105         int i;
 106         /* Mask/clear interrupts. */
 107         *PER_INT_MSK_REG  = 0x00000000;
 108         *PER_INT_STS_REG  = 0xFFFFFFFF;
 109         /* initialize all the IRQ descriptors */
 110         for (i = MSP_PER_INTBASE; i < MSP_PER_INTBASE + 32; i++) {
 111                 irq_set_chip(i, &msp_per_irq_controller);
 112         }
 113 }
 114
 115 void msp_per_irq_dispatch(void)
 116 {
 117         u32     per_mask = *PER_INT_MSK_REG;
 118         u32     per_status = *PER_INT_STS_REG;
 119         u32     pending;
 120
 121         pending = per_status & per_mask;
 122         if (pending) {
 123                 do_IRQ(ffs(pending) + MSP_PER_INTBASE - 1);
 124         } else {
 125                 spurious_interrupt();
 126         }
 127 }