1 #include <linux/stddef.h>
2 #include <linux/init.h>
3 #include <linux/sched.h>
4 #include <linux/signal.h>
5 #include <asm/irq.h>
6 #include <asm/immap_cpm2.h>
7 #include <asm/mpc8260.h>
8 #include "cpm2_pic.h"
9 
10 /* The CPM2 internal interrupt controller.  It is usually
11  * the only interrupt controller.
12  * There are two 32-bit registers (high/low) for up to 64
13  * possible interrupts.
14  *
15  * Now, the fun starts.....Interrupt Numbers DO NOT MAP
16  * in a simple arithmetic fashion to mask or pending registers.
17  * That is, interrupt 4 does not map to bit position 4.
18  * We create two tables, indexed by vector number, to indicate
19  * which register to use and which bit in the register to use.
20  */
21 static	u_char	irq_to_siureg[] = {
22 	1, 1, 1, 1, 1, 1, 1, 1,
23 	1, 1, 1, 1, 1, 1, 1, 1,
24 	0, 0, 0, 0, 0, 0, 0, 0,
25 	0, 0, 0, 0, 0, 0, 0, 0,
26 	1, 1, 1, 1, 1, 1, 1, 1,
27 	1, 1, 1, 1, 1, 1, 1, 1,
28 	0, 0, 0, 0, 0, 0, 0, 0,
29 	0, 0, 0, 0, 0, 0, 0, 0
30 };
31 
32 static	u_char	irq_to_siubit[] = {
33 	31, 16, 17, 18, 19, 20, 21, 22,
34 	23, 24, 25, 26, 27, 28, 29, 30,
35 	29, 30, 16, 17, 18, 19, 20, 21,
36 	22, 23, 24, 25, 26, 27, 28, 31,
37 	 0,  1,  2,  3,  4,  5,  6,  7,
38 	 8,  9, 10, 11, 12, 13, 14, 15,
39 	15, 14, 13, 12, 11, 10,  9,  8,
40 	 7,  6,  5,  4,  3,  2,  1,  0
41 };
42 
cpm2_mask_irq(unsigned int irq_nr)43 static void cpm2_mask_irq(unsigned int irq_nr)
44 {
45 	int	bit, word;
46 	volatile uint	*simr;
47 
48 	bit = irq_to_siubit[irq_nr];
49 	word = irq_to_siureg[irq_nr];
50 
51 	simr = &(cpm2_immr->im_intctl.ic_simrh);
52 	ppc_cached_irq_mask[word] &= ~(1 << (31 - bit));
53 	simr[word] = ppc_cached_irq_mask[word];
54 }
55 
cpm2_unmask_irq(unsigned int irq_nr)56 static void cpm2_unmask_irq(unsigned int irq_nr)
57 {
58 	int	bit, word;
59 	volatile uint	*simr;
60 
61 	bit = irq_to_siubit[irq_nr];
62 	word = irq_to_siureg[irq_nr];
63 
64 	simr = &(cpm2_immr->im_intctl.ic_simrh);
65 	ppc_cached_irq_mask[word] |= (1 << (31 - bit));
66 	simr[word] = ppc_cached_irq_mask[word];
67 }
68 
cpm2_mask_and_ack(unsigned int irq_nr)69 static void cpm2_mask_and_ack(unsigned int irq_nr)
70 {
71 	int	bit, word;
72 	volatile uint	*simr, *sipnr;
73 
74 	bit = irq_to_siubit[irq_nr];
75 	word = irq_to_siureg[irq_nr];
76 
77 	simr = &(cpm2_immr->im_intctl.ic_simrh);
78 	sipnr = &(cpm2_immr->im_intctl.ic_sipnrh);
79 	ppc_cached_irq_mask[word] &= ~(1 << (31 - bit));
80 	simr[word] = ppc_cached_irq_mask[word];
81 	sipnr[word] = 1 << (31 - bit);
82 }
83 
cpm2_end_irq(unsigned int irq_nr)84 static void cpm2_end_irq(unsigned int irq_nr)
85 {
86 	int	bit, word;
87 	volatile uint	*simr;
88 
89 	if (!(irq_desc[irq_nr].status & (IRQ_DISABLED|IRQ_INPROGRESS))) {
90 
91 		bit = irq_to_siubit[irq_nr];
92 		word = irq_to_siureg[irq_nr];
93 
94 		simr = &(cpm2_immr->im_intctl.ic_simrh);
95 		ppc_cached_irq_mask[word] |= (1 << (31 - bit));
96 		simr[word] = ppc_cached_irq_mask[word];
97 	}
98 }
99 
100 struct hw_interrupt_type cpm2_pic = {
101 	" CPM2 SIU  ",
102 	NULL,
103 	NULL,
104 	cpm2_unmask_irq,
105 	cpm2_mask_irq,
106 	cpm2_mask_and_ack,
107 	cpm2_end_irq,
108 	0
109 };
110 
111 /* Return an interrupt vector or -1 if no interrupt is pending. */
112 int
cpm2_get_irq(struct pt_regs * regs)113 cpm2_get_irq(struct pt_regs *regs)
114 {
115 	int irq;
116         unsigned long bits;
117 
118         /* For CPM2, read the SIVEC register and shift the bits down
119          * to get the irq number.         */
120         bits = cpm2_immr->im_intctl.ic_sivec;
121         irq = bits >> 26;
122 
123 	if (irq == 0)	/* 0 --> no irq is pending */
124 		irq = -1;
125 
126 	return irq;
127 }
128 
129