1 /*
2 * Apple Peripheral System Controller (PSC)
3 *
4 * The PSC is used on the AV Macs to control IO functions not handled
5 * by the VIAs (Ethernet, DSP, SCC).
6 *
7 * TO DO:
8 *
9 * Try to figure out what's going on in pIFR5 and pIFR6. There seem to be
10 * persisant interrupt conditions in those registers and I have no idea what
11 * they are. Granted it doesn't affect since we're not enabling any interrupts
12 * on those levels at the moment, but it would be nice to know. I have a feeling
13 * they aren't actually interrupt lines but data lines (to the DSP?)
14 */
15
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/mm.h>
19 #include <linux/delay.h>
20 #include <linux/init.h>
21
22 #include <asm/traps.h>
23 #include <asm/bootinfo.h>
24 #include <asm/macintosh.h>
25 #include <asm/macints.h>
26 #include <asm/mac_psc.h>
27
28 #define DEBUG_PSC
29
30 int psc_present;
31 volatile __u8 *psc;
32
33 irqreturn_t psc_irq(int, void *);
34
35 /*
36 * Debugging dump, used in various places to see what's going on.
37 */
38
psc_debug_dump(void)39 static void psc_debug_dump(void)
40 {
41 int i;
42
43 if (!psc_present) return;
44 for (i = 0x30 ; i < 0x70 ; i += 0x10) {
45 printk("PSC #%d: IFR = 0x%02X IER = 0x%02X\n",
46 i >> 4,
47 (int) psc_read_byte(pIFRbase + i),
48 (int) psc_read_byte(pIERbase + i));
49 }
50 }
51
52 /*
53 * Try to kill all DMA channels on the PSC. Not sure how this his
54 * supposed to work; this is code lifted from macmace.c and then
55 * expanded to cover what I think are the other 7 channels.
56 */
57
psc_dma_die_die_die(void)58 static void psc_dma_die_die_die(void)
59 {
60 int i;
61
62 printk("Killing all PSC DMA channels...");
63 for (i = 0 ; i < 9 ; i++) {
64 psc_write_word(PSC_CTL_BASE + (i << 4), 0x8800);
65 psc_write_word(PSC_CTL_BASE + (i << 4), 0x1000);
66 psc_write_word(PSC_CMD_BASE + (i << 5), 0x1100);
67 psc_write_word(PSC_CMD_BASE + (i << 5) + 0x10, 0x1100);
68 }
69 printk("done!\n");
70 }
71
72 /*
73 * Initialize the PSC. For now this just involves shutting down all
74 * interrupt sources using the IERs.
75 */
76
psc_init(void)77 void __init psc_init(void)
78 {
79 int i;
80
81 if (macintosh_config->ident != MAC_MODEL_C660
82 && macintosh_config->ident != MAC_MODEL_Q840)
83 {
84 psc = NULL;
85 psc_present = 0;
86 return;
87 }
88
89 /*
90 * The PSC is always at the same spot, but using psc
91 * keeps things consisant with the psc_xxxx functions.
92 */
93
94 psc = (void *) PSC_BASE;
95 psc_present = 1;
96
97 printk("PSC detected at %p\n", psc);
98
99 psc_dma_die_die_die();
100
101 #ifdef DEBUG_PSC
102 psc_debug_dump();
103 #endif
104 /*
105 * Mask and clear all possible interrupts
106 */
107
108 for (i = 0x30 ; i < 0x70 ; i += 0x10) {
109 psc_write_byte(pIERbase + i, 0x0F);
110 psc_write_byte(pIFRbase + i, 0x0F);
111 }
112 }
113
114 /*
115 * Register the PSC interrupt dispatchers for autovector interrupts 3-6.
116 */
117
psc_register_interrupts(void)118 void __init psc_register_interrupts(void)
119 {
120 if (request_irq(IRQ_AUTO_3, psc_irq, 0, "psc3", (void *) 0x30))
121 pr_err("Couldn't register psc%d interrupt\n", 3);
122 if (request_irq(IRQ_AUTO_4, psc_irq, 0, "psc4", (void *) 0x40))
123 pr_err("Couldn't register psc%d interrupt\n", 4);
124 if (request_irq(IRQ_AUTO_5, psc_irq, 0, "psc5", (void *) 0x50))
125 pr_err("Couldn't register psc%d interrupt\n", 5);
126 if (request_irq(IRQ_AUTO_6, psc_irq, 0, "psc6", (void *) 0x60))
127 pr_err("Couldn't register psc%d interrupt\n", 6);
128 }
129
130 /*
131 * PSC interrupt handler. It's a lot like the VIA interrupt handler.
132 */
133
psc_irq(int irq,void * dev_id)134 irqreturn_t psc_irq(int irq, void *dev_id)
135 {
136 int pIFR = pIFRbase + ((int) dev_id);
137 int pIER = pIERbase + ((int) dev_id);
138 int irq_num;
139 unsigned char irq_bit, events;
140
141 #ifdef DEBUG_IRQS
142 printk("psc_irq: irq %d pIFR = 0x%02X pIER = 0x%02X\n",
143 irq, (int) psc_read_byte(pIFR), (int) psc_read_byte(pIER));
144 #endif
145
146 events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF;
147 if (!events)
148 return IRQ_NONE;
149
150 irq_num = irq << 3;
151 irq_bit = 1;
152 do {
153 if (events & irq_bit) {
154 psc_write_byte(pIFR, irq_bit);
155 m68k_handle_int(irq_num);
156 }
157 irq_num++;
158 irq_bit <<= 1;
159 } while (events >= irq_bit);
160 return IRQ_HANDLED;
161 }
162
psc_irq_enable(int irq)163 void psc_irq_enable(int irq) {
164 int irq_src = IRQ_SRC(irq);
165 int irq_idx = IRQ_IDX(irq);
166 int pIER = pIERbase + (irq_src << 4);
167
168 #ifdef DEBUG_IRQUSE
169 printk("psc_irq_enable(%d)\n", irq);
170 #endif
171 psc_write_byte(pIER, (1 << irq_idx) | 0x80);
172 }
173
psc_irq_disable(int irq)174 void psc_irq_disable(int irq) {
175 int irq_src = IRQ_SRC(irq);
176 int irq_idx = IRQ_IDX(irq);
177 int pIER = pIERbase + (irq_src << 4);
178
179 #ifdef DEBUG_IRQUSE
180 printk("psc_irq_disable(%d)\n", irq);
181 #endif
182 psc_write_byte(pIER, 1 << irq_idx);
183 }
184
psc_irq_clear(int irq)185 void psc_irq_clear(int irq) {
186 int irq_src = IRQ_SRC(irq);
187 int irq_idx = IRQ_IDX(irq);
188 int pIFR = pIERbase + (irq_src << 4);
189
190 psc_write_byte(pIFR, 1 << irq_idx);
191 }
192
psc_irq_pending(int irq)193 int psc_irq_pending(int irq)
194 {
195 int irq_src = IRQ_SRC(irq);
196 int irq_idx = IRQ_IDX(irq);
197 int pIFR = pIERbase + (irq_src << 4);
198
199 return psc_read_byte(pIFR) & (1 << irq_idx);
200 }
201