1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	linux/arch/alpha/kernel/sys_miata.c
4  *
5  *	Copyright (C) 1995 David A Rusling
6  *	Copyright (C) 1996 Jay A Estabrook
7  *	Copyright (C) 1998, 1999, 2000 Richard Henderson
8  *
9  * Code supporting the MIATA (EV56+PYXIS).
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 #include <linux/reboot.h>
19 
20 #include <asm/ptrace.h>
21 #include <asm/dma.h>
22 #include <asm/irq.h>
23 #include <asm/mmu_context.h>
24 #include <asm/io.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 
33 
34 static void
miata_srm_device_interrupt(unsigned long vector)35 miata_srm_device_interrupt(unsigned long vector)
36 {
37 	int irq;
38 
39 	irq = (vector - 0x800) >> 4;
40 
41 	/*
42 	 * I really hate to do this, but the MIATA SRM console ignores the
43 	 *  low 8 bits in the interrupt summary register, and reports the
44 	 *  vector 0x80 *lower* than I expected from the bit numbering in
45 	 *  the documentation.
46 	 * This was done because the low 8 summary bits really aren't used
47 	 *  for reporting any interrupts (the PCI-ISA bridge, bit 7, isn't
48 	 *  used for this purpose, as PIC interrupts are delivered as the
49 	 *  vectors 0x800-0x8f0).
50 	 * But I really don't want to change the fixup code for allocation
51 	 *  of IRQs, nor the alpha_irq_mask maintenance stuff, both of which
52 	 *  look nice and clean now.
53 	 * So, here's this grotty hack... :-(
54 	 */
55 	if (irq >= 16)
56 		irq = irq + 8;
57 
58 	handle_irq(irq);
59 }
60 
61 static void __init
miata_init_irq(void)62 miata_init_irq(void)
63 {
64 	if (alpha_using_srm)
65 		alpha_mv.device_interrupt = miata_srm_device_interrupt;
66 
67 #if 0
68 	/* These break on MiataGL so we'll try not to do it at all.  */
69 	*(vulp)PYXIS_INT_HILO = 0x000000B2UL; mb();	/* ISA/NMI HI */
70 	*(vulp)PYXIS_RT_COUNT = 0UL; mb();		/* clear count */
71 #endif
72 
73 	init_i8259a_irqs();
74 
75 	/* Not interested in the bogus interrupts (3,10), Fan Fault (0),
76            NMI (1), or EIDE (9).
77 
78 	   We also disable the risers (4,5), since we don't know how to
79 	   route the interrupts behind the bridge.  */
80 	init_pyxis_irqs(0x63b0000);
81 
82 	common_init_isa_dma();
83 	if (request_irq(16 + 2, no_action, 0, "halt-switch", NULL))
84 		pr_err("Failed to register halt-switch interrupt\n");
85 	if (request_irq(16 + 6, no_action, 0, "timer-cascade", NULL))
86 		pr_err("Failed to register timer-cascade interrupt\n");
87 }
88 
89 
90 /*
91  * PCI Fixup configuration.
92  *
93  * Summary @ PYXIS_INT_REQ:
94  * Bit      Meaning
95  * 0        Fan Fault
96  * 1        NMI
97  * 2        Halt/Reset switch
98  * 3        none
99  * 4        CID0 (Riser ID)
100  * 5        CID1 (Riser ID)
101  * 6        Interval timer
102  * 7        PCI-ISA Bridge
103  * 8        Ethernet
104  * 9        EIDE (deprecated, ISA 14/15 used)
105  *10        none
106  *11        USB
107  *12        Interrupt Line A from slot 4
108  *13        Interrupt Line B from slot 4
109  *14        Interrupt Line C from slot 4
110  *15        Interrupt Line D from slot 4
111  *16        Interrupt Line A from slot 5
112  *17        Interrupt line B from slot 5
113  *18        Interrupt Line C from slot 5
114  *19        Interrupt Line D from slot 5
115  *20        Interrupt Line A from slot 1
116  *21        Interrupt Line B from slot 1
117  *22        Interrupt Line C from slot 1
118  *23        Interrupt Line D from slot 1
119  *24        Interrupt Line A from slot 2
120  *25        Interrupt Line B from slot 2
121  *26        Interrupt Line C from slot 2
122  *27        Interrupt Line D from slot 2
123  *27        Interrupt Line A from slot 3
124  *29        Interrupt Line B from slot 3
125  *30        Interrupt Line C from slot 3
126  *31        Interrupt Line D from slot 3
127  *
128  * The device to slot mapping looks like:
129  *
130  * Slot     Device
131  *  3       DC21142 Ethernet
132  *  4       EIDE CMD646
133  *  5       none
134  *  6       USB
135  *  7       PCI-ISA bridge
136  *  8       PCI-PCI Bridge      (SBU Riser)
137  *  9       none
138  * 10       none
139  * 11       PCI on board slot 4 (SBU Riser)
140  * 12       PCI on board slot 5 (SBU Riser)
141  *
142  *  These are behind the bridge, so I'm not sure what to do...
143  *
144  * 13       PCI on board slot 1 (SBU Riser)
145  * 14       PCI on board slot 2 (SBU Riser)
146  * 15       PCI on board slot 3 (SBU Riser)
147  *
148  *
149  * This two layered interrupt approach means that we allocate IRQ 16 and
150  * above for PCI interrupts.  The IRQ relates to which bit the interrupt
151  * comes in on.  This makes interrupt processing much easier.
152  */
153 
154 static int
miata_map_irq(const struct pci_dev * dev,u8 slot,u8 pin)155 miata_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
156 {
157         static char irq_tab[18][5] = {
158 		/*INT    INTA   INTB   INTC   INTD */
159 		{16+ 8, 16+ 8, 16+ 8, 16+ 8, 16+ 8},  /* IdSel 14,  DC21142 */
160 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 15,  EIDE    */
161 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 16,  none    */
162 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 17,  none    */
163 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 18,  PCI-ISA */
164 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 19,  PCI-PCI */
165 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 20,  none    */
166 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 21,  none    */
167 		{16+12, 16+12, 16+13, 16+14, 16+15},  /* IdSel 22,  slot 4  */
168 		{16+16, 16+16, 16+17, 16+18, 16+19},  /* IdSel 23,  slot 5  */
169 		/* the next 7 are actually on PCI bus 1, across the bridge */
170 		{16+11, 16+11, 16+11, 16+11, 16+11},  /* IdSel 24,  QLISP/GL*/
171 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 25,  none    */
172 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 26,  none    */
173 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 27,  none    */
174 		{16+20, 16+20, 16+21, 16+22, 16+23},  /* IdSel 28,  slot 1  */
175 		{16+24, 16+24, 16+25, 16+26, 16+27},  /* IdSel 29,  slot 2  */
176 		{16+28, 16+28, 16+29, 16+30, 16+31},  /* IdSel 30,  slot 3  */
177 		/* This bridge is on the main bus of the later orig MIATA */
178 		{   -1,    -1,    -1,    -1,    -1},  /* IdSel 31,  PCI-PCI */
179         };
180 	const long min_idsel = 3, max_idsel = 20, irqs_per_slot = 5;
181 
182 	/* the USB function of the 82c693 has it's interrupt connected to
183            the 2nd 8259 controller. So we have to check for it first. */
184 
185 	if((slot == 7) && (PCI_FUNC(dev->devfn) == 3)) {
186 		struct pci_dev *pdev = pci_get_slot(dev->bus, dev->devfn & ~7);
187 		u8 irq = 0;
188 		int ret;
189 
190 		if (!pdev)
191 			return -1;
192 
193 		ret = pci_read_config_byte(pdev, 0x40, &irq);
194 		pci_dev_put(pdev);
195 
196 		return ret == PCIBIOS_SUCCESSFUL ? irq : -1;
197 	}
198 
199 	return COMMON_TABLE_LOOKUP;
200 }
201 
202 static u8
miata_swizzle(struct pci_dev * dev,u8 * pinp)203 miata_swizzle(struct pci_dev *dev, u8 *pinp)
204 {
205 	int slot, pin = *pinp;
206 
207 	if (dev->bus->number == 0) {
208 		slot = PCI_SLOT(dev->devfn);
209 	}
210 	/* Check for the built-in bridge.  */
211 	else if ((PCI_SLOT(dev->bus->self->devfn) == 8) ||
212 		 (PCI_SLOT(dev->bus->self->devfn) == 20)) {
213 		slot = PCI_SLOT(dev->devfn) + 9;
214 	}
215 	else
216 	{
217 		/* Must be a card-based bridge.  */
218 		do {
219 			if ((PCI_SLOT(dev->bus->self->devfn) == 8) ||
220 			    (PCI_SLOT(dev->bus->self->devfn) == 20)) {
221 				slot = PCI_SLOT(dev->devfn) + 9;
222 				break;
223 			}
224 			pin = pci_swizzle_interrupt_pin(dev, pin);
225 
226 			/* Move up the chain of bridges.  */
227 			dev = dev->bus->self;
228 			/* Slot of the next bridge.  */
229 			slot = PCI_SLOT(dev->devfn);
230 		} while (dev->bus->self);
231 	}
232 	*pinp = pin;
233 	return slot;
234 }
235 
236 static void __init
miata_init_pci(void)237 miata_init_pci(void)
238 {
239 	cia_init_pci();
240 	SMC669_Init(0); /* it might be a GL (fails harmlessly if not) */
241 	es1888_init();
242 }
243 
244 static void
miata_kill_arch(int mode)245 miata_kill_arch(int mode)
246 {
247 	cia_kill_arch(mode);
248 
249 #ifndef ALPHA_RESTORE_SRM_SETUP
250 	switch(mode) {
251 	case LINUX_REBOOT_CMD_RESTART:
252 		/* Who said DEC engineers have no sense of humor? ;-)  */
253 		if (alpha_using_srm) {
254 			*(vuip) PYXIS_RESET = 0x0000dead;
255 			mb();
256 		}
257 		break;
258 	case LINUX_REBOOT_CMD_HALT:
259 		break;
260 	case LINUX_REBOOT_CMD_POWER_OFF:
261 		break;
262 	}
263 
264 	halt();
265 #endif
266 }
267 
268 
269 /*
270  * The System Vector
271  */
272 
273 struct alpha_machine_vector miata_mv __initmv = {
274 	.vector_name		= "Miata",
275 	DO_EV5_MMU,
276 	DO_DEFAULT_RTC,
277 	DO_PYXIS_IO,
278 	.machine_check		= cia_machine_check,
279 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
280 	.min_io_address		= DEFAULT_IO_BASE,
281 	.min_mem_address	= DEFAULT_MEM_BASE,
282 	.pci_dac_offset		= PYXIS_DAC_OFFSET,
283 
284 	.nr_irqs		= 48,
285 	.device_interrupt	= pyxis_device_interrupt,
286 
287 	.init_arch		= pyxis_init_arch,
288 	.init_irq		= miata_init_irq,
289 	.init_rtc		= common_init_rtc,
290 	.init_pci		= miata_init_pci,
291 	.kill_arch		= miata_kill_arch,
292 	.pci_map_irq		= miata_map_irq,
293 	.pci_swizzle		= miata_swizzle,
294 };
295 ALIAS_MV(miata)
296