aboutsummaryrefslogtreecommitdiffstats
path: root/arch/ppc/syslib/cpm2_pic.c
blob: 29d95d415ceb7f70accd8c8381f9666f748be467 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/* The CPM2 internal interrupt controller.  It is usually
 * the only interrupt controller.
 * There are two 32-bit registers (high/low) for up to 64
 * possible interrupts.
 *
 * Now, the fun starts.....Interrupt Numbers DO NOT MAP
 * in a simple arithmetic fashion to mask or pending registers.
 * That is, interrupt 4 does not map to bit position 4.
 * We create two tables, indexed by vector number, to indicate
 * which register to use and which bit in the register to use.
 */

#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/irq.h>

#include <asm/immap_cpm2.h>
#include <asm/mpc8260.h>

#include "cpm2_pic.h"

static	u_char	irq_to_siureg[] = {
	1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0
};

/* bit numbers do not match the docs, these are precomputed so the bit for
 * a given irq is (1 << irq_to_siubit[irq]) */
static	u_char	irq_to_siubit[] = {
	 0, 15, 14, 13, 12, 11, 10,  9,
	 8,  7,  6,  5,  4,  3,  2,  1,
	 2,  1,  0, 14, 13, 12, 11, 10,
	 9,  8,  7,  6,  5,  4,  3,  0,
	31, 30, 29, 28, 27, 26, 25, 24,
	23, 22, 21, 20, 19, 18, 17, 16,
	16, 17, 18, 19, 20, 21, 22, 23,
	24, 25, 26, 27, 28, 29, 30, 31,
};

static void cpm2_mask_irq(unsigned int irq_nr)
{
	int	bit, word;
	volatile uint	*simr;

	irq_nr -= CPM_IRQ_OFFSET;

	bit = irq_to_siubit[irq_nr];
	word = irq_to_siureg[irq_nr];

	simr = &(cpm2_immr->im_intctl.ic_simrh);
	ppc_cached_irq_mask[word] &= ~(1 << bit);
	simr[word] = ppc_cached_irq_mask[word];
}

static void cpm2_unmask_irq(unsigned int irq_nr)
{
	int	bit, word;
	volatile uint	*simr;

	irq_nr -= CPM_IRQ_OFFSET;

	bit = irq_to_siubit[irq_nr];
	word = irq_to_siureg[irq_nr];

	simr = &(cpm2_immr->im_intctl.ic_simrh);
	ppc_cached_irq_mask[word] |= 1 << bit;
	simr[word] = ppc_cached_irq_mask[word];
}

static void cpm2_mask_and_ack(unsigned int irq_nr)
{
	int	bit, word;
	volatile uint	*simr, *sipnr;

	irq_nr -= CPM_IRQ_OFFSET;

	bit = irq_to_siubit[irq_nr];
	word = irq_to_siureg[irq_nr];

	simr = &(cpm2_immr->im_intctl.ic_simrh);
	sipnr = &(cpm2_immr->im_intctl.ic_sipnrh);
	ppc_cached_irq_mask[word] &= ~(1 << bit);
	simr[word] = ppc_cached_irq_mask[word];
	sipnr[word] = 1 << bit;
}

static void cpm2_end_irq(unsigned int irq_nr)
{
	int	bit, word;
	volatile uint	*simr;

	if (!(irq_desc[irq_nr].status & (IRQ_DISABLED|IRQ_INPROGRESS))
			&& irq_desc[irq_nr].action) {

		irq_nr -= CPM_IRQ_OFFSET;
		bit = irq_to_siubit[irq_nr];
		word = irq_to_siureg[irq_nr];

		simr = &(cpm2_immr->im_intctl.ic_simrh);
		ppc_cached_irq_mask[word] |= 1 << bit;
		simr[word] = ppc_cached_irq_mask[word];
		/*
		 * Work around large numbers of spurious IRQs on PowerPC 82xx
		 * systems.
		 */
		mb();
	}
}

static struct hw_interrupt_type cpm2_pic = {
	.typename = " CPM2 SIU ",
	.enable = cpm2_unmask_irq,
	.disable = cpm2_mask_irq,
	.ack = cpm2_mask_and_ack,
	.end = cpm2_end_irq,
};

int cpm2_get_irq(struct pt_regs *regs)
{
	int irq;
        unsigned long bits;

        /* For CPM2, read the SIVEC register and shift the bits down
         * to get the irq number.         */
        bits = cpm2_immr->im_intctl.ic_sivec;
        irq = bits >> 26;

	if (irq == 0)
		return(-1);
	return irq+CPM_IRQ_OFFSET;
}

void cpm2_init_IRQ(void)
{
	int i;

	/* Clear the CPM IRQ controller, in case it has any bits set
	 * from the bootloader
	 */

	/* Mask out everything */
	cpm2_immr->im_intctl.ic_simrh = 0x00000000;
	cpm2_immr->im_intctl.ic_simrl = 0x00000000;
	wmb();

	/* Ack everything */
	cpm2_immr->im_intctl.ic_sipnrh = 0xffffffff;
	cpm2_immr->im_intctl.ic_sipnrl = 0xffffffff;
	wmb();

	/* Dummy read of the vector */
	i = cpm2_immr->im_intctl.ic_sivec;
	rmb();

	/* Initialize the default interrupt mapping priorities,
	 * in case the boot rom changed something on us.
	 */
	cpm2_immr->im_intctl.ic_sicr = 0;
	cpm2_immr->im_intctl.ic_scprrh = 0x05309770;
	cpm2_immr->im_intctl.ic_scprrl = 0x05309770;


	/* Enable chaining to OpenPIC, and make everything level
	 */
	for (i = 0; i < NR_CPM_INTS; i++) {
		irq_desc[i+CPM_IRQ_OFFSET].handler = &cpm2_pic;
		irq_desc[i+CPM_IRQ_OFFSET].status |= IRQ_LEVEL;
	}
}