xref: /linux/arch/alpha/kernel/sys_rx164.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  *	linux/arch/alpha/kernel/sys_rx164.c
3  *
4  *	Copyright (C) 1995 David A Rusling
5  *	Copyright (C) 1996 Jay A Estabrook
6  *	Copyright (C) 1998, 1999 Richard Henderson
7  *
8  * Code supporting the RX164 (PCA56+POLARIS).
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/types.h>
13 #include <linux/mm.h>
14 #include <linux/sched.h>
15 #include <linux/pci.h>
16 #include <linux/init.h>
17 #include <linux/bitops.h>
18 
19 #include <asm/ptrace.h>
20 #include <asm/system.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/pgtable.h>
26 #include <asm/core_polaris.h>
27 #include <asm/tlbflush.h>
28 
29 #include "proto.h"
30 #include "irq_impl.h"
31 #include "pci_impl.h"
32 #include "machvec_impl.h"
33 
34 
35 /* Note mask bit is true for ENABLED irqs.  */
36 static unsigned long cached_irq_mask;
37 
38 static inline void
39 rx164_update_irq_hw(unsigned long mask)
40 {
41 	volatile unsigned int *irq_mask;
42 
43 	irq_mask = (void *)(POLARIS_DENSE_CONFIG_BASE + 0x74);
44 	*irq_mask = mask;
45 	mb();
46 	*irq_mask;
47 }
48 
49 static inline void
50 rx164_enable_irq(unsigned int irq)
51 {
52 	rx164_update_irq_hw(cached_irq_mask |= 1UL << (irq - 16));
53 }
54 
55 static void
56 rx164_disable_irq(unsigned int irq)
57 {
58 	rx164_update_irq_hw(cached_irq_mask &= ~(1UL << (irq - 16)));
59 }
60 
61 static unsigned int
62 rx164_startup_irq(unsigned int irq)
63 {
64 	rx164_enable_irq(irq);
65 	return 0;
66 }
67 
68 static void
69 rx164_end_irq(unsigned int irq)
70 {
71 	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
72 		rx164_enable_irq(irq);
73 }
74 
75 static struct hw_interrupt_type rx164_irq_type = {
76 	.typename	= "RX164",
77 	.startup	= rx164_startup_irq,
78 	.shutdown	= rx164_disable_irq,
79 	.enable		= rx164_enable_irq,
80 	.disable	= rx164_disable_irq,
81 	.ack		= rx164_disable_irq,
82 	.end		= rx164_end_irq,
83 };
84 
85 static void
86 rx164_device_interrupt(unsigned long vector, struct pt_regs *regs)
87 {
88 	unsigned long pld;
89 	volatile unsigned int *dirr;
90 	long i;
91 
92 	/* Read the interrupt summary register.  On Polaris, this is
93 	   the DIRR register in PCI config space (offset 0x84).  */
94 	dirr = (void *)(POLARIS_DENSE_CONFIG_BASE + 0x84);
95 	pld = *dirr;
96 
97 	/*
98 	 * Now for every possible bit set, work through them and call
99 	 * the appropriate interrupt handler.
100 	 */
101 	while (pld) {
102 		i = ffz(~pld);
103 		pld &= pld - 1; /* clear least bit set */
104 		if (i == 20) {
105 			isa_no_iack_sc_device_interrupt(vector, regs);
106 		} else {
107 			handle_irq(16+i, regs);
108 		}
109 	}
110 }
111 
112 static void __init
113 rx164_init_irq(void)
114 {
115 	long i;
116 
117 	rx164_update_irq_hw(0);
118 	for (i = 16; i < 40; ++i) {
119 		irq_desc[i].status = IRQ_DISABLED | IRQ_LEVEL;
120 		irq_desc[i].chip = &rx164_irq_type;
121 	}
122 
123 	init_i8259a_irqs();
124 	common_init_isa_dma();
125 
126 	setup_irq(16+20, &isa_cascade_irqaction);
127 }
128 
129 
130 /*
131  * The RX164 changed its interrupt routing between pass1 and pass2...
132  *
133  * PASS1:
134  *
135  *      Slot    IDSEL   INTA    INTB    INTC    INTD
136  *      0       6       5       10      15      20
137  *      1       7       4       9       14      19
138  *      2       5       3       8       13      18
139  *      3       9       2       7       12      17
140  *      4       10      1       6       11      16
141  *
142  * PASS2:
143  *      Slot    IDSEL   INTA    INTB    INTC    INTD
144  *      0       5       1       7       12      17
145  *      1       6       2       8       13      18
146  *      2       8       3       9       14      19
147  *      3       9       4       10      15      20
148  *      4       10      5       11      16      6
149  *
150  */
151 
152 /*
153  * IdSel
154  *   5  32 bit PCI option slot 0
155  *   6  64 bit PCI option slot 1
156  *   7  PCI-ISA bridge
157  *   7  64 bit PCI option slot 2
158  *   9  32 bit PCI option slot 3
159  *  10  PCI-PCI bridge
160  *
161  */
162 
163 static int __init
164 rx164_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
165 {
166 #if 0
167 	static char irq_tab_pass1[6][5] __initdata = {
168 	  /*INT   INTA  INTB  INTC   INTD */
169 	  { 16+3, 16+3, 16+8, 16+13, 16+18},      /* IdSel 5,  slot 2 */
170 	  { 16+5, 16+5, 16+10, 16+15, 16+20},     /* IdSel 6,  slot 0 */
171 	  { 16+4, 16+4, 16+9, 16+14, 16+19},      /* IdSel 7,  slot 1 */
172 	  { -1,     -1,    -1,    -1,   -1},      /* IdSel 8, PCI/ISA bridge */
173 	  { 16+2, 16+2, 16+7, 16+12, 16+17},      /* IdSel 9,  slot 3 */
174 	  { 16+1, 16+1, 16+6, 16+11, 16+16},      /* IdSel 10, slot 4 */
175 	};
176 #else
177 	static char irq_tab[6][5] __initdata = {
178 	  /*INT   INTA  INTB  INTC   INTD */
179 	  { 16+0, 16+0, 16+6, 16+11, 16+16},      /* IdSel 5,  slot 0 */
180 	  { 16+1, 16+1, 16+7, 16+12, 16+17},      /* IdSel 6,  slot 1 */
181 	  { -1,     -1,    -1,    -1,   -1},      /* IdSel 7, PCI/ISA bridge */
182 	  { 16+2, 16+2, 16+8, 16+13, 16+18},      /* IdSel 8,  slot 2 */
183 	  { 16+3, 16+3, 16+9, 16+14, 16+19},      /* IdSel 9,  slot 3 */
184 	  { 16+4, 16+4, 16+10, 16+15, 16+5},      /* IdSel 10, PCI-PCI */
185 	};
186 #endif
187 	const long min_idsel = 5, max_idsel = 10, irqs_per_slot = 5;
188 
189 	/* JRP - Need to figure out how to distinguish pass1 from pass2,
190 	   and use the correct table.  */
191 	return COMMON_TABLE_LOOKUP;
192 }
193 
194 
195 /*
196  * The System Vector
197  */
198 
199 struct alpha_machine_vector rx164_mv __initmv = {
200 	.vector_name		= "RX164",
201 	DO_EV5_MMU,
202 	DO_DEFAULT_RTC,
203 	DO_POLARIS_IO,
204 	.machine_check		= polaris_machine_check,
205 	.max_isa_dma_address	= ALPHA_MAX_ISA_DMA_ADDRESS,
206 	.min_io_address		= DEFAULT_IO_BASE,
207 	.min_mem_address	= DEFAULT_MEM_BASE,
208 
209 	.nr_irqs		= 40,
210 	.device_interrupt	= rx164_device_interrupt,
211 
212 	.init_arch		= polaris_init_arch,
213 	.init_irq		= rx164_init_irq,
214 	.init_rtc		= common_init_rtc,
215 	.init_pci		= common_init_pci,
216 	.kill_arch		= NULL,
217 	.pci_map_irq		= rx164_map_irq,
218 	.pci_swizzle		= common_swizzle,
219 };
220 ALIAS_MV(rx164)
221