xref: /openbmc/linux/drivers/parisc/gsc.c (revision 93dc544c)
1 /*
2  * Interrupt management for most GSC and related devices.
3  *
4  * (c) Copyright 1999 Alex deVries for The Puffin Group
5  * (c) Copyright 1999 Grant Grundler for Hewlett-Packard
6  * (c) Copyright 1999 Matthew Wilcox
7  * (c) Copyright 2000 Helge Deller
8  * (c) Copyright 2001 Matthew Wilcox for Hewlett-Packard
9  *
10  *	This program is free software; you can redistribute it and/or modify
11  *	it under the terms of the GNU General Public License as published by
12  *      the Free Software Foundation; either version 2 of the License, or
13  *      (at your option) any later version.
14  */
15 
16 #include <linux/bitops.h>
17 #include <linux/errno.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/ioport.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/types.h>
24 
25 #include <asm/hardware.h>
26 #include <asm/io.h>
27 
28 #include "gsc.h"
29 
30 #undef DEBUG
31 
32 #ifdef DEBUG
33 #define DEBPRINTK printk
34 #else
35 #define DEBPRINTK(x,...)
36 #endif
37 
38 int gsc_alloc_irq(struct gsc_irq *i)
39 {
40 	int irq = txn_alloc_irq(GSC_EIM_WIDTH);
41 	if (irq < 0) {
42 		printk("cannot get irq\n");
43 		return irq;
44 	}
45 
46 	i->txn_addr = txn_alloc_addr(irq);
47 	i->txn_data = txn_alloc_data(irq);
48 	i->irq = irq;
49 
50 	return irq;
51 }
52 
53 int gsc_claim_irq(struct gsc_irq *i, int irq)
54 {
55 	int c = irq;
56 
57 	irq += CPU_IRQ_BASE; /* virtualize the IRQ first */
58 
59 	irq = txn_claim_irq(irq);
60 	if (irq < 0) {
61 		printk("cannot claim irq %d\n", c);
62 		return irq;
63 	}
64 
65 	i->txn_addr = txn_alloc_addr(irq);
66 	i->txn_data = txn_alloc_data(irq);
67 	i->irq = irq;
68 
69 	return irq;
70 }
71 
72 EXPORT_SYMBOL(gsc_alloc_irq);
73 EXPORT_SYMBOL(gsc_claim_irq);
74 
75 /* Common interrupt demultiplexer used by Asp, Lasi & Wax.  */
76 irqreturn_t gsc_asic_intr(int gsc_asic_irq, void *dev)
77 {
78 	unsigned long irr;
79 	struct gsc_asic *gsc_asic = dev;
80 
81 	irr = gsc_readl(gsc_asic->hpa + OFFSET_IRR);
82 	if (irr == 0)
83 		return IRQ_NONE;
84 
85 	DEBPRINTK("%s intr, mask=0x%x\n", gsc_asic->name, irr);
86 
87 	do {
88 		int local_irq = __ffs(irr);
89 		unsigned int irq = gsc_asic->global_irq[local_irq];
90 		__do_IRQ(irq);
91 		irr &= ~(1 << local_irq);
92 	} while (irr);
93 
94 	return IRQ_HANDLED;
95 }
96 
97 int gsc_find_local_irq(unsigned int irq, int *global_irqs, int limit)
98 {
99 	int local_irq;
100 
101 	for (local_irq = 0; local_irq < limit; local_irq++) {
102 		if (global_irqs[local_irq] == irq)
103 			return local_irq;
104 	}
105 
106 	return NO_IRQ;
107 }
108 
109 static void gsc_asic_disable_irq(unsigned int irq)
110 {
111 	struct gsc_asic *irq_dev = irq_desc[irq].chip_data;
112 	int local_irq = gsc_find_local_irq(irq, irq_dev->global_irq, 32);
113 	u32 imr;
114 
115 	DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, irq,
116 			irq_dev->name, imr);
117 
118 	/* Disable the IRQ line by clearing the bit in the IMR */
119 	imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
120 	imr &= ~(1 << local_irq);
121 	gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
122 }
123 
124 static void gsc_asic_enable_irq(unsigned int irq)
125 {
126 	struct gsc_asic *irq_dev = irq_desc[irq].chip_data;
127 	int local_irq = gsc_find_local_irq(irq, irq_dev->global_irq, 32);
128 	u32 imr;
129 
130 	DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, irq,
131 			irq_dev->name, imr);
132 
133 	/* Enable the IRQ line by setting the bit in the IMR */
134 	imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
135 	imr |= 1 << local_irq;
136 	gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
137 	/*
138 	 * FIXME: read IPR to make sure the IRQ isn't already pending.
139 	 *   If so, we need to read IRR and manually call do_irq().
140 	 */
141 }
142 
143 static unsigned int gsc_asic_startup_irq(unsigned int irq)
144 {
145 	gsc_asic_enable_irq(irq);
146 	return 0;
147 }
148 
149 static struct hw_interrupt_type gsc_asic_interrupt_type = {
150 	.typename =	"GSC-ASIC",
151 	.startup =	gsc_asic_startup_irq,
152 	.shutdown =	gsc_asic_disable_irq,
153 	.enable =	gsc_asic_enable_irq,
154 	.disable =	gsc_asic_disable_irq,
155 	.ack =		no_ack_irq,
156 	.end =		no_end_irq,
157 };
158 
159 int gsc_assign_irq(struct hw_interrupt_type *type, void *data)
160 {
161 	static int irq = GSC_IRQ_BASE;
162 
163 	if (irq > GSC_IRQ_MAX)
164 		return NO_IRQ;
165 
166 	irq_desc[irq].chip = type;
167 	irq_desc[irq].chip_data = data;
168 	return irq++;
169 }
170 
171 void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp)
172 {
173 	int irq = asic->global_irq[local_irq];
174 
175 	if (irq <= 0) {
176 		irq = gsc_assign_irq(&gsc_asic_interrupt_type, asic);
177 		if (irq == NO_IRQ)
178 			return;
179 
180 		asic->global_irq[local_irq] = irq;
181 	}
182 	*irqp = irq;
183 }
184 
185 static struct device *next_device(struct klist_iter *i)
186 {
187 	struct klist_node * n = klist_next(i);
188 	return n ? container_of(n, struct device, knode_parent) : NULL;
189 }
190 
191 void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl,
192 			void (*choose_irq)(struct parisc_device *, void *))
193 {
194 	struct device *dev;
195 	struct klist_iter i;
196 
197 	klist_iter_init(&parent->dev.klist_children, &i);
198 	while ((dev = next_device(&i))) {
199 		struct parisc_device *padev = to_parisc_device(dev);
200 
201 		/* work-around for 715/64 and others which have parent
202 		   at path [5] and children at path [5/0/x] */
203 		if (padev->id.hw_type == HPHW_FAULTY)
204 			return gsc_fixup_irqs(padev, ctrl, choose_irq);
205 		choose_irq(padev, ctrl);
206 	}
207 	klist_iter_exit(&i);
208 }
209 
210 int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic)
211 {
212 	struct resource *res;
213 	int i;
214 
215 	gsc_asic->gsc = parent;
216 
217 	/* Initialise local irq -> global irq mapping */
218 	for (i = 0; i < 32; i++) {
219 		gsc_asic->global_irq[i] = NO_IRQ;
220 	}
221 
222 	/* allocate resource region */
223 	res = request_mem_region(gsc_asic->hpa, 0x100000, gsc_asic->name);
224 	if (res) {
225 		res->flags = IORESOURCE_MEM; 	/* do not mark it busy ! */
226 	}
227 
228 #if 0
229 	printk(KERN_WARNING "%s IRQ %d EIM 0x%x", gsc_asic->name,
230 			parent->irq, gsc_asic->eim);
231 	if (gsc_readl(gsc_asic->hpa + OFFSET_IMR))
232 		printk("  IMR is non-zero! (0x%x)",
233 				gsc_readl(gsc_asic->hpa + OFFSET_IMR));
234 	printk("\n");
235 #endif
236 
237 	return 0;
238 }
239 
240 extern struct parisc_driver lasi_driver;
241 extern struct parisc_driver asp_driver;
242 extern struct parisc_driver wax_driver;
243 
244 void __init gsc_init(void)
245 {
246 #ifdef CONFIG_GSC_LASI
247 	register_parisc_driver(&lasi_driver);
248 	register_parisc_driver(&asp_driver);
249 #endif
250 #ifdef CONFIG_GSC_WAX
251 	register_parisc_driver(&wax_driver);
252 #endif
253 }
254