xref: /openbmc/linux/arch/alpha/kernel/sys_takara.c (revision f21e49be)
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