1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/arch/alpha/kernel/sys_takara.c
4 *
5 * Copyright (C) 1995 David A Rusling
6 * Copyright (C) 1996 Jay A Estabrook
7 * Copyright (C) 1998, 1999 Richard Henderson
8 *
9 * Code supporting the TAKARA.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14 #include <linux/mm.h>
15 #include <linux/sched.h>
16 #include <linux/pci.h>
17 #include <linux/init.h>
18
19 #include <asm/ptrace.h>
20 #include <asm/dma.h>
21 #include <asm/irq.h>
22 #include <asm/mmu_context.h>
23 #include <asm/io.h>
24 #include <asm/core_cia.h>
25 #include <asm/tlbflush.h>
26
27 #include "proto.h"
28 #include "irq_impl.h"
29 #include "pci_impl.h"
30 #include "machvec_impl.h"
31 #include "pc873xx.h"
32
33 /* Note mask bit is true for DISABLED irqs. */
34 static unsigned long cached_irq_mask[2] = { -1, -1 };
35
36 static inline void
37 takara_update_irq_hw(unsigned long irq, unsigned long mask)
38 {
39 int regaddr;
40
41 mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30));
42 regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c);
43 outl(mask & 0xffff0000UL, regaddr);
44 }
45
46 static inline void
47 takara_enable_irq(struct irq_data *d)
48 {
49 unsigned int irq = d->irq;
50 unsigned long mask;
51 mask = (cached_irq_mask[irq >= 64] &= ~(1UL << (irq & 63)));
52 takara_update_irq_hw(irq, mask);
53 }
54
55 static void
56 takara_disable_irq(struct irq_data *d)
57 {
58 unsigned int irq = d->irq;
59 unsigned long mask;
60 mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63));
61 takara_update_irq_hw(irq, mask);
62 }
63
64 static struct irq_chip takara_irq_type = {
65 .name = "TAKARA",
66 .irq_unmask = takara_enable_irq,
67 .irq_mask = takara_disable_irq,
68 .irq_mask_ack = takara_disable_irq,
69 };
70
71 static void
72 takara_device_interrupt(unsigned long vector)
73 {
74 unsigned intstatus;
75
76 /*
77 * The PALcode will have passed us vectors 0x800 or 0x810,
78 * which are fairly arbitrary values and serve only to tell
79 * us whether an interrupt has come in on IRQ0 or IRQ1. If
80 * it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's
81 * probably ISA, but PCI interrupts can come through IRQ0
82 * as well if the interrupt controller isn't in accelerated
83 * mode.
84 *
85 * OTOH, the accelerator thing doesn't seem to be working
86 * overly well, so what we'll do instead is try directly
87 * examining the Master Interrupt Register to see if it's a
88 * PCI interrupt, and if _not_ then we'll pass it on to the
89 * ISA handler.
90 */
91
92 intstatus = inw(0x500) & 15;
93 if (intstatus) {
94 /*
95 * This is a PCI interrupt. Check each bit and
96 * despatch an interrupt if it's set.
97 */
98
99 if (intstatus & 8) handle_irq(16+3);
100 if (intstatus & 4) handle_irq(16+2);
101 if (intstatus & 2) handle_irq(16+1);
102 if (intstatus & 1) handle_irq(16+0);
103 } else {
104 isa_device_interrupt (vector);
105 }
106 }
107
108 static void
109 takara_srm_device_interrupt(unsigned long vector)
110 {
111 int irq = (vector - 0x800) >> 4;
112 handle_irq(irq);
113 }
114
115 static void __init
116 takara_init_irq(void)
117 {
118 long i;
119
120 init_i8259a_irqs();
121
122 if (alpha_using_srm) {
123 alpha_mv.device_interrupt = takara_srm_device_interrupt;
124 } else {
125 unsigned int ctlreg = inl(0x500);
126
127 /* Return to non-accelerated mode. */
128 ctlreg &= ~0x8000;
129 outl(ctlreg, 0x500);
130
131 /* Enable the PCI interrupt register. */
132 ctlreg = 0x05107c00;
133 outl(ctlreg, 0x500);
134 }
135
136 for (i = 16; i < 128; i += 16)
137 takara_update_irq_hw(i, -1);
138
139 for (i = 16; i < 128; ++i) {
140 irq_set_chip_and_handler(i, &takara_irq_type,
141 handle_level_irq);
142 irq_set_status_flags(i, IRQ_LEVEL);
143 }
144
145 common_init_isa_dma();
146 }
147
148
149 /*
150 * The Takara has PCI devices 1, 2, and 3 configured to slots 20,
151 * 19, and 18 respectively, in the default configuration. They can
152 * also be jumpered to slots 8, 7, and 6 respectively, which is fun
153 * because the SIO ISA bridge can also be slot 7. However, the SIO
154 * doesn't explicitly generate PCI-type interrupts, so we can
155 * assign it whatever the hell IRQ we like and it doesn't matter.
156 */
157
158 static int
159 takara_map_irq_srm(const struct pci_dev *dev, u8 slot, u8 pin)
160 {
161 static char irq_tab[15][5] = {
162 { 16+3, 16+3, 16+3, 16+3, 16+3}, /* slot 6 == device 3 */
163 { 16+2, 16+2, 16+2, 16+2, 16+2}, /* slot 7 == device 2 */
164 { 16+1, 16+1, 16+1, 16+1, 16+1}, /* slot 8 == device 1 */
165 { -1, -1, -1, -1, -1}, /* slot 9 == nothing */
166 { -1, -1, -1, -1, -1}, /* slot 10 == nothing */
167 { -1, -1, -1, -1, -1}, /* slot 11 == nothing */
168 /* These are behind the bridges. */
169 { 12, 12, 13, 14, 15}, /* slot 12 == nothing */
170 { 8, 8, 9, 19, 11}, /* slot 13 == nothing */
171 { 4, 4, 5, 6, 7}, /* slot 14 == nothing */
172 { 0, 0, 1, 2, 3}, /* slot 15 == nothing */
173 { -1, -1, -1, -1, -1}, /* slot 16 == nothing */
174 {64+ 0, 64+0, 64+1, 64+2, 64+3}, /* slot 17= device 4 */
175 {48+ 0, 48+0, 48+1, 48+2, 48+3}, /* slot 18= device 3 */
176 {32+ 0, 32+0, 32+1, 32+2, 32+3}, /* slot 19= device 2 */
177 {16+ 0, 16+0, 16+1, 16+2, 16+3}, /* slot 20= device 1 */
178 };
179 const long min_idsel = 6, max_idsel = 20, irqs_per_slot = 5;
180 int irq = COMMON_TABLE_LOOKUP;
181 if (irq >= 0 && irq < 16) {
182 /* Guess that we are behind a bridge. */
183 unsigned int busslot = PCI_SLOT(dev->bus->self->devfn);
184 irq += irq_tab[busslot-min_idsel][0];
185 }
186 return irq;
187 }
188
189 static int __init
190 takara_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
191 {
192 static char irq_tab[15][5] __initdata = {
193 { 16+3, 16+3, 16+3, 16+3, 16+3}, /* slot 6 == device 3 */
194 { 16+2, 16+2, 16+2, 16+2, 16+2}, /* slot 7 == device 2 */
195 { 16+1, 16+1, 16+1, 16+1, 16+1}, /* slot 8 == device 1 */
196 { -1, -1, -1, -1, -1}, /* slot 9 == nothing */
197 { -1, -1, -1, -1, -1}, /* slot 10 == nothing */
198 { -1, -1, -1, -1, -1}, /* slot 11 == nothing */
199 { -1, -1, -1, -1, -1}, /* slot 12 == nothing */
200 { -1, -1, -1, -1, -1}, /* slot 13 == nothing */
201 { -1, -1, -1, -1, -1}, /* slot 14 == nothing */
202 { -1, -1, -1, -1, -1}, /* slot 15 == nothing */
203 { -1, -1, -1, -1, -1}, /* slot 16 == nothing */
204 { -1, -1, -1, -1, -1}, /* slot 17 == nothing */
205 { 16+3, 16+3, 16+3, 16+3, 16+3}, /* slot 18 == device 3 */
206 { 16+2, 16+2, 16+2, 16+2, 16+2}, /* slot 19 == device 2 */
207 { 16+1, 16+1, 16+1, 16+1, 16+1}, /* slot 20 == device 1 */
208 };
209 const long min_idsel = 6, max_idsel = 20, irqs_per_slot = 5;
210 return COMMON_TABLE_LOOKUP;
211 }
212
213 static u8
214 takara_swizzle(struct pci_dev *dev, u8 *pinp)
215 {
216 int slot = PCI_SLOT(dev->devfn);
217 int pin = *pinp;
218 unsigned int ctlreg = inl(0x500);
219 unsigned int busslot;
220
221 if (!dev->bus->self)
222 return slot;
223
224 busslot = PCI_SLOT(dev->bus->self->devfn);
225 /* Check for built-in bridges. */
226 if (dev->bus->number != 0
227 && busslot > 16
228 && ((1<<(36-busslot)) & ctlreg)) {
229 if (pin == 1)
230 pin += (20 - busslot);
231 else {
232 printk(KERN_WARNING "takara_swizzle: can only "
233 "handle cards with INTA IRQ pin.\n");
234 }
235 } else {
236 /* Must be a card-based bridge. */
237 printk(KERN_WARNING "takara_swizzle: cannot handle "
238 "card-bridge behind builtin bridge yet.\n");
239 }
240
241 *pinp = pin;
242 return slot;
243 }
244
245 static void __init
246 takara_init_pci(void)
247 {
248 if (alpha_using_srm)
249 alpha_mv.pci_map_irq = takara_map_irq_srm;
250
251 cia_init_pci();
252
253 if (pc873xx_probe() == -1) {
254 printk(KERN_ERR "Probing for PC873xx Super IO chip failed.\n");
255 } else {
256 printk(KERN_INFO "Found %s Super IO chip at 0x%x\n",
257 pc873xx_get_model(), pc873xx_get_base());
258 pc873xx_enable_ide();
259 }
260 }
261
262
263 /*
264 * The System Vector
265 */
266
267 struct alpha_machine_vector takara_mv __initmv = {
268 .vector_name = "Takara",
269 DO_EV5_MMU,
270 DO_DEFAULT_RTC,
271 DO_CIA_IO,
272 .machine_check = cia_machine_check,
273 .max_isa_dma_address = ALPHA_MAX_ISA_DMA_ADDRESS,
274 .min_io_address = DEFAULT_IO_BASE,
275 .min_mem_address = CIA_DEFAULT_MEM_BASE,
276
277 .nr_irqs = 128,
278 .device_interrupt = takara_device_interrupt,
279
280 .init_arch = cia_init_arch,
281 .init_irq = takara_init_irq,
282 .init_rtc = common_init_rtc,
283 .init_pci = takara_init_pci,
284 .kill_arch = cia_kill_arch,
285 .pci_map_irq = takara_map_irq,
286 .pci_swizzle = takara_swizzle,
287 };
288 ALIAS_MV(takara)
289
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