1 /*
2 * Copyright 2010 PMC-Sierra, Inc, derived from irq_cpu.c
3 *
4 * This file define the irq handler for MSP PER subsystem interrupts.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 */
11
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/spinlock.h>
16 #include <linux/bitops.h>
17
18 #include <asm/mipsregs.h>
19 #include <asm/system.h>
20
21 #include <msp_cic_int.h>
22 #include <msp_regs.h>
23
24
25 /*
26 * Convenience Macro. Should be somewhere generic.
27 */
28 #define get_current_vpe() \
29 ((read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) & TCBIND_CURVPE)
30
31 #ifdef CONFIG_SMP
32 /*
33 * The PER registers must be protected from concurrent access.
34 */
35
36 static DEFINE_SPINLOCK(per_lock);
37 #endif
38
39 /* ensure writes to per are completed */
40
per_wmb(void)41 static inline void per_wmb(void)
42 {
43 const volatile void __iomem *per_mem = PER_INT_MSK_REG;
44 volatile u32 dummy_read;
45
46 wmb();
47 dummy_read = __raw_readl(per_mem);
48 dummy_read++;
49 }
50
unmask_per_irq(struct irq_data * d)51 static inline void unmask_per_irq(struct irq_data *d)
52 {
53 #ifdef CONFIG_SMP
54 unsigned long flags;
55 spin_lock_irqsave(&per_lock, flags);
56 *PER_INT_MSK_REG |= (1 << (d->irq - MSP_PER_INTBASE));
57 spin_unlock_irqrestore(&per_lock, flags);
58 #else
59 *PER_INT_MSK_REG |= (1 << (d->irq - MSP_PER_INTBASE));
60 #endif
61 per_wmb();
62 }
63
mask_per_irq(struct irq_data * d)64 static inline void mask_per_irq(struct irq_data *d)
65 {
66 #ifdef CONFIG_SMP
67 unsigned long flags;
68 spin_lock_irqsave(&per_lock, flags);
69 *PER_INT_MSK_REG &= ~(1 << (d->irq - MSP_PER_INTBASE));
70 spin_unlock_irqrestore(&per_lock, flags);
71 #else
72 *PER_INT_MSK_REG &= ~(1 << (d->irq - MSP_PER_INTBASE));
73 #endif
74 per_wmb();
75 }
76
msp_per_irq_ack(struct irq_data * d)77 static inline void msp_per_irq_ack(struct irq_data *d)
78 {
79 mask_per_irq(d);
80 /*
81 * In the PER interrupt controller, only bits 11 and 10
82 * are write-to-clear, (SPI TX complete, SPI RX complete).
83 * It does nothing for any others.
84 */
85 *PER_INT_STS_REG = (1 << (d->irq - MSP_PER_INTBASE));
86 }
87
88 #ifdef CONFIG_SMP
msp_per_irq_set_affinity(struct irq_data * d,const struct cpumask * affinity,bool force)89 static int msp_per_irq_set_affinity(struct irq_data *d,
90 const struct cpumask *affinity, bool force)
91 {
92 /* WTF is this doing ????? */
93 unmask_per_irq(d);
94 return 0;
95 }
96 #endif
97
98 static struct irq_chip msp_per_irq_controller = {
99 .name = "MSP_PER",
100 .irq_enable = unmask_per_irq,
101 .irq_disable = mask_per_irq,
102 .irq_ack = msp_per_irq_ack,
103 #ifdef CONFIG_SMP
104 .irq_set_affinity = msp_per_irq_set_affinity,
105 #endif
106 };
107
msp_per_irq_init(void)108 void __init msp_per_irq_init(void)
109 {
110 int i;
111 /* Mask/clear interrupts. */
112 *PER_INT_MSK_REG = 0x00000000;
113 *PER_INT_STS_REG = 0xFFFFFFFF;
114 /* initialize all the IRQ descriptors */
115 for (i = MSP_PER_INTBASE; i < MSP_PER_INTBASE + 32; i++) {
116 irq_set_chip(i, &msp_per_irq_controller);
117 #ifdef CONFIG_MIPS_MT_SMTC
118 irq_hwmask[i] = C_IRQ4;
119 #endif
120 }
121 }
122
msp_per_irq_dispatch(void)123 void msp_per_irq_dispatch(void)
124 {
125 u32 per_mask = *PER_INT_MSK_REG;
126 u32 per_status = *PER_INT_STS_REG;
127 u32 pending;
128
129 pending = per_status & per_mask;
130 if (pending) {
131 do_IRQ(ffs(pending) + MSP_PER_INTBASE - 1);
132 } else {
133 spurious_interrupt();
134 }
135 }
136