xref: /openbmc/linux/arch/alpha/kernel/sys_takara.c (revision e3b9f1e8)
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/pgtable.h>
25 #include <asm/core_cia.h>
26 #include <asm/tlbflush.h>
27 
28 #include "proto.h"
29 #include "irq_impl.h"
30 #include "pci_impl.h"
31 #include "machvec_impl.h"
32 #include "pc873xx.h"
33 
34 /* Note mask bit is true for DISABLED irqs.  */
35 static unsigned long cached_irq_mask[2] = { -1, -1 };
36 
37 static inline void
38 takara_update_irq_hw(unsigned long irq, unsigned long mask)
39 {
40 	int regaddr;
41 
42 	mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30));
43 	regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c);
44 	outl(mask & 0xffff0000UL, regaddr);
45 }
46 
47 static inline void
48 takara_enable_irq(struct irq_data *d)
49 {
50 	unsigned int irq = d->irq;
51 	unsigned long mask;
52 	mask = (cached_irq_mask[irq >= 64] &= ~(1UL << (irq & 63)));
53 	takara_update_irq_hw(irq, mask);
54 }
55 
56 static void
57 takara_disable_irq(struct irq_data *d)
58 {
59 	unsigned int irq = d->irq;
60 	unsigned long mask;
61 	mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63));
62 	takara_update_irq_hw(irq, mask);
63 }
64 
65 static struct irq_chip takara_irq_type = {
66 	.name		= "TAKARA",
67 	.irq_unmask	= takara_enable_irq,
68 	.irq_mask	= takara_disable_irq,
69 	.irq_mask_ack	= takara_disable_irq,
70 };
71 
72 static void
73 takara_device_interrupt(unsigned long vector)
74 {
75 	unsigned intstatus;
76 
77 	/*
78 	 * The PALcode will have passed us vectors 0x800 or 0x810,
79 	 * which are fairly arbitrary values and serve only to tell
80 	 * us whether an interrupt has come in on IRQ0 or IRQ1. If
81 	 * it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's
82 	 * probably ISA, but PCI interrupts can come through IRQ0
83 	 * as well if the interrupt controller isn't in accelerated
84 	 * mode.
85 	 *
86 	 * OTOH, the accelerator thing doesn't seem to be working
87 	 * overly well, so what we'll do instead is try directly
88 	 * examining the Master Interrupt Register to see if it's a
89 	 * PCI interrupt, and if _not_ then we'll pass it on to the
90 	 * ISA handler.
91 	 */
92 
93 	intstatus = inw(0x500) & 15;
94 	if (intstatus) {
95 		/*
96 		 * This is a PCI interrupt. Check each bit and
97 		 * despatch an interrupt if it's set.
98 		 */
99 
100 		if (intstatus & 8) handle_irq(16+3);
101 		if (intstatus & 4) handle_irq(16+2);
102 		if (intstatus & 2) handle_irq(16+1);
103 		if (intstatus & 1) handle_irq(16+0);
104 	} else {
105 		isa_device_interrupt (vector);
106 	}
107 }
108 
109 static void
110 takara_srm_device_interrupt(unsigned long vector)
111 {
112 	int irq = (vector - 0x800) >> 4;
113 	handle_irq(irq);
114 }
115 
116 static void __init
117 takara_init_irq(void)
118 {
119 	long i;
120 
121 	init_i8259a_irqs();
122 
123 	if (alpha_using_srm) {
124 		alpha_mv.device_interrupt = takara_srm_device_interrupt;
125 	} else {
126 		unsigned int ctlreg = inl(0x500);
127 
128 		/* Return to non-accelerated mode.  */
129 		ctlreg &= ~0x8000;
130 		outl(ctlreg, 0x500);
131 
132 		/* Enable the PCI interrupt register.  */
133 		ctlreg = 0x05107c00;
134 		outl(ctlreg, 0x500);
135 	}
136 
137 	for (i = 16; i < 128; i += 16)
138 		takara_update_irq_hw(i, -1);
139 
140 	for (i = 16; i < 128; ++i) {
141 		irq_set_chip_and_handler(i, &takara_irq_type,
142 					 handle_level_irq);
143 		irq_set_status_flags(i, IRQ_LEVEL);
144 	}
145 
146 	common_init_isa_dma();
147 }
148 
149 
150 /*
151  * The Takara has PCI devices 1, 2, and 3 configured to slots 20,
152  * 19, and 18 respectively, in the default configuration. They can
153  * also be jumpered to slots 8, 7, and 6 respectively, which is fun
154  * because the SIO ISA bridge can also be slot 7. However, the SIO
155  * doesn't explicitly generate PCI-type interrupts, so we can
156  * assign it whatever the hell IRQ we like and it doesn't matter.
157  */
158 
159 static int
160 takara_map_irq_srm(const struct pci_dev *dev, u8 slot, u8 pin)
161 {
162 	static char irq_tab[15][5] = {
163 		{ 16+3, 16+3, 16+3, 16+3, 16+3},   /* slot  6 == device 3 */
164 		{ 16+2, 16+2, 16+2, 16+2, 16+2},   /* slot  7 == device 2 */
165 		{ 16+1, 16+1, 16+1, 16+1, 16+1},   /* slot  8 == device 1 */
166 		{   -1,   -1,   -1,   -1,   -1},   /* slot  9 == nothing */
167 		{   -1,   -1,   -1,   -1,   -1},   /* slot 10 == nothing */
168 		{   -1,   -1,   -1,   -1,   -1},   /* slot 11 == nothing */
169 		/* These are behind the bridges.  */
170 		{   12,   12,   13,   14,   15},   /* slot 12 == nothing */
171 		{    8,    8,    9,   19,   11},   /* slot 13 == nothing */
172 		{    4,    4,    5,    6,    7},   /* slot 14 == nothing */
173 		{    0,    0,    1,    2,    3},   /* slot 15 == nothing */
174 		{   -1,   -1,   -1,   -1,   -1},   /* slot 16 == nothing */
175 		{64+ 0, 64+0, 64+1, 64+2, 64+3},   /* slot 17= device 4 */
176 		{48+ 0, 48+0, 48+1, 48+2, 48+3},   /* slot 18= device 3 */
177 		{32+ 0, 32+0, 32+1, 32+2, 32+3},   /* slot 19= device 2 */
178 		{16+ 0, 16+0, 16+1, 16+2, 16+3},   /* slot 20= device 1 */
179 	};
180 	const long min_idsel = 6, max_idsel = 20, irqs_per_slot = 5;
181         int irq = COMMON_TABLE_LOOKUP;
182 	if (irq >= 0 && irq < 16) {
183 		/* Guess that we are behind a bridge.  */
184 		unsigned int busslot = PCI_SLOT(dev->bus->self->devfn);
185 		irq += irq_tab[busslot-min_idsel][0];
186 	}
187 	return irq;
188 }
189 
190 static int __init
191 takara_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
192 {
193 	static char irq_tab[15][5] __initdata = {
194 		{ 16+3, 16+3, 16+3, 16+3, 16+3},   /* slot  6 == device 3 */
195 		{ 16+2, 16+2, 16+2, 16+2, 16+2},   /* slot  7 == device 2 */
196 		{ 16+1, 16+1, 16+1, 16+1, 16+1},   /* slot  8 == device 1 */
197 		{   -1,   -1,   -1,   -1,   -1},   /* slot  9 == nothing */
198 		{   -1,   -1,   -1,   -1,   -1},   /* slot 10 == nothing */
199 		{   -1,   -1,   -1,   -1,   -1},   /* slot 11 == nothing */
200 		{   -1,   -1,   -1,   -1,   -1},   /* slot 12 == nothing */
201 		{   -1,   -1,   -1,   -1,   -1},   /* slot 13 == nothing */
202 		{   -1,   -1,   -1,   -1,   -1},   /* slot 14 == nothing */
203 		{   -1,   -1,   -1,   -1,   -1},   /* slot 15 == nothing */
204 		{   -1,   -1,   -1,   -1,   -1},   /* slot 16 == nothing */
205 		{   -1,   -1,   -1,   -1,   -1},   /* slot 17 == nothing */
206 		{ 16+3, 16+3, 16+3, 16+3, 16+3},   /* slot 18 == device 3 */
207 		{ 16+2, 16+2, 16+2, 16+2, 16+2},   /* slot 19 == device 2 */
208 		{ 16+1, 16+1, 16+1, 16+1, 16+1},   /* slot 20 == device 1 */
209 	};
210 	const long min_idsel = 6, max_idsel = 20, irqs_per_slot = 5;
211 	return COMMON_TABLE_LOOKUP;
212 }
213 
214 static u8
215 takara_swizzle(struct pci_dev *dev, u8 *pinp)
216 {
217 	int slot = PCI_SLOT(dev->devfn);
218 	int pin = *pinp;
219 	unsigned int ctlreg = inl(0x500);
220 	unsigned int busslot;
221 
222 	if (!dev->bus->self)
223 		return slot;
224 
225 	busslot = PCI_SLOT(dev->bus->self->devfn);
226 	/* Check for built-in bridges.  */
227 	if (dev->bus->number != 0
228 	    && busslot > 16
229 	    && ((1<<(36-busslot)) & ctlreg)) {
230 		if (pin == 1)
231 			pin += (20 - busslot);
232 		else {
233 			printk(KERN_WARNING "takara_swizzle: can only "
234 			       "handle cards with INTA IRQ pin.\n");
235 		}
236 	} else {
237 		/* Must be a card-based bridge.  */
238 		printk(KERN_WARNING "takara_swizzle: cannot handle "
239 		       "card-bridge behind builtin bridge yet.\n");
240 	}
241 
242 	*pinp = pin;
243 	return slot;
244 }
245 
246 static void __init
247 takara_init_pci(void)
248 {
249 	if (alpha_using_srm)
250 		alpha_mv.pci_map_irq = takara_map_irq_srm;
251 
252 	cia_init_pci();
253 
254 	if (pc873xx_probe() == -1) {
255 		printk(KERN_ERR "Probing for PC873xx Super IO chip failed.\n");
256 	} else {
257 		printk(KERN_INFO "Found %s Super IO chip at 0x%x\n",
258 			pc873xx_get_model(), pc873xx_get_base());
259 		pc873xx_enable_ide();
260 	}
261 }
262 
263 
264 /*
265  * The System Vector
266  */
267 
268 struct alpha_machine_vector takara_mv __initmv = {
269 	.vector_name		= "Takara",
270 	DO_EV5_MMU,
271 	DO_DEFAULT_RTC,
272 	DO_CIA_IO,
273 	.machine_check		= cia_machine_check,
274 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
275 	.min_io_address		= DEFAULT_IO_BASE,
276 	.min_mem_address	= CIA_DEFAULT_MEM_BASE,
277 
278 	.nr_irqs		= 128,
279 	.device_interrupt	= takara_device_interrupt,
280 
281 	.init_arch		= cia_init_arch,
282 	.init_irq		= takara_init_irq,
283 	.init_rtc		= common_init_rtc,
284 	.init_pci		= takara_init_pci,
285 	.kill_arch		= cia_kill_arch,
286 	.pci_map_irq		= takara_map_irq,
287 	.pci_swizzle		= takara_swizzle,
288 };
289 ALIAS_MV(takara)
290