summaryrefslogtreecommitdiff
path: root/arch/m68k/mac/psc.c
blob: 8dd71c555e939d223e49f61e5bd579fd3f564827 (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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
/*
 *	Apple Peripheral System Controller (PSC)
 *
 *	The PSC is used on the AV Macs to control IO functions not handled
 *	by the VIAs (Ethernet, DSP, SCC).
 *
 * TO DO:
 *
 * Try to figure out what's going on in pIFR5 and pIFR6. There seem to be
 * persisant interrupt conditions in those registers and I have no idea what
 * they are. Granted it doesn't affect since we're not enabling any interrupts
 * on those levels at the moment, but it would be nice to know. I have a feeling
 * they aren't actually interrupt lines but data lines (to the DSP?)
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/irq.h>

#include <asm/traps.h>
#include <asm/bootinfo.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_psc.h>

#define DEBUG_PSC

int psc_present;
volatile __u8 *psc;

/*
 * Debugging dump, used in various places to see what's going on.
 */

static void psc_debug_dump(void)
{
	int	i;

	if (!psc_present) return;
	for (i = 0x30 ; i < 0x70 ; i += 0x10) {
		printk("PSC #%d:  IFR = 0x%02X IER = 0x%02X\n",
			i >> 4,
			(int) psc_read_byte(pIFRbase + i),
			(int) psc_read_byte(pIERbase + i));
	}
}

/*
 * Try to kill all DMA channels on the PSC. Not sure how this his
 * supposed to work; this is code lifted from macmace.c and then
 * expanded to cover what I think are the other 7 channels.
 */

static void psc_dma_die_die_die(void)
{
	int i;

	printk("Killing all PSC DMA channels...");
	for (i = 0 ; i < 9 ; i++) {
		psc_write_word(PSC_CTL_BASE + (i << 4), 0x8800);
		psc_write_word(PSC_CTL_BASE + (i << 4), 0x1000);
		psc_write_word(PSC_CMD_BASE + (i << 5), 0x1100);
		psc_write_word(PSC_CMD_BASE + (i << 5) + 0x10, 0x1100);
	}
	printk("done!\n");
}

/*
 * Initialize the PSC. For now this just involves shutting down all
 * interrupt sources using the IERs.
 */

void __init psc_init(void)
{
	int i;

	if (macintosh_config->ident != MAC_MODEL_C660
	 && macintosh_config->ident != MAC_MODEL_Q840)
	{
		psc = NULL;
		psc_present = 0;
		return;
	}

	/*
	 * The PSC is always at the same spot, but using psc
	 * keeps things consistent with the psc_xxxx functions.
	 */

	psc = (void *) PSC_BASE;
	psc_present = 1;

	printk("PSC detected at %p\n", psc);

	psc_dma_die_die_die();

#ifdef DEBUG_PSC
	psc_debug_dump();
#endif
	/*
	 * Mask and clear all possible interrupts
	 */

	for (i = 0x30 ; i < 0x70 ; i += 0x10) {
		psc_write_byte(pIERbase + i, 0x0F);
		psc_write_byte(pIFRbase + i, 0x0F);
	}
}

/*
 * PSC interrupt handler. It's a lot like the VIA interrupt handler.
 */

static void psc_irq(unsigned int irq, struct irq_desc *desc)
{
	unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc);
	int pIFR	= pIFRbase + offset;
	int pIER	= pIERbase + offset;
	int irq_num;
	unsigned char irq_bit, events;

#ifdef DEBUG_IRQS
	printk("psc_irq: irq %u pIFR = 0x%02X pIER = 0x%02X\n",
		irq, (int) psc_read_byte(pIFR), (int) psc_read_byte(pIER));
#endif

	events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF;
	if (!events)
		return;

	irq_num = irq << 3;
	irq_bit = 1;
	do {
		if (events & irq_bit) {
			psc_write_byte(pIFR, irq_bit);
			generic_handle_irq(irq_num);
		}
		irq_num++;
		irq_bit <<= 1;
	} while (events >= irq_bit);
}

/*
 * Register the PSC interrupt dispatchers for autovector interrupts 3-6.
 */

void __init psc_register_interrupts(void)
{
	irq_set_chained_handler(IRQ_AUTO_3, psc_irq);
	irq_set_handler_data(IRQ_AUTO_3, (void *)0x30);
	irq_set_chained_handler(IRQ_AUTO_4, psc_irq);
	irq_set_handler_data(IRQ_AUTO_4, (void *)0x40);
	irq_set_chained_handler(IRQ_AUTO_5, psc_irq);
	irq_set_handler_data(IRQ_AUTO_5, (void *)0x50);
	irq_set_chained_handler(IRQ_AUTO_6, psc_irq);
	irq_set_handler_data(IRQ_AUTO_6, (void *)0x60);
}

void psc_irq_enable(int irq) {
	int irq_src	= IRQ_SRC(irq);
	int irq_idx	= IRQ_IDX(irq);
	int pIER	= pIERbase + (irq_src << 4);

#ifdef DEBUG_IRQUSE
	printk("psc_irq_enable(%d)\n", irq);
#endif
	psc_write_byte(pIER, (1 << irq_idx) | 0x80);
}

void psc_irq_disable(int irq) {
	int irq_src	= IRQ_SRC(irq);
	int irq_idx	= IRQ_IDX(irq);
	int pIER	= pIERbase + (irq_src << 4);

#ifdef DEBUG_IRQUSE
	printk("psc_irq_disable(%d)\n", irq);
#endif
	psc_write_byte(pIER, 1 << irq_idx);
}

int psc_irq_pending(int irq)
{
	int irq_src	= IRQ_SRC(irq);
	int irq_idx	= IRQ_IDX(irq);
	int pIFR	= pIERbase + (irq_src << 4);

	return psc_read_byte(pIFR) & (1 << irq_idx);
}