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/types.h>
23
24#include <asm/hardware.h>
25#include <asm/io.h>
26
27#include "gsc.h"
28
29#undef DEBUG
30
31#ifdef DEBUG
32#define DEBPRINTK printk
33#else
34#define DEBPRINTK(x,...)
35#endif
36
37int gsc_alloc_irq(struct gsc_irq *i)
38{
39	int irq = txn_alloc_irq(GSC_EIM_WIDTH);
40	if (irq < 0) {
41		printk("cannot get irq\n");
42		return irq;
43	}
44
45	i->txn_addr = txn_alloc_addr(irq);
46	i->txn_data = txn_alloc_data(irq);
47	i->irq = irq;
48
49	return irq;
50}
51
52int gsc_claim_irq(struct gsc_irq *i, int irq)
53{
54	int c = irq;
55
56	irq += CPU_IRQ_BASE; /* virtualize the IRQ first */
57
58	irq = txn_claim_irq(irq);
59	if (irq < 0) {
60		printk("cannot claim irq %d\n", c);
61		return irq;
62	}
63
64	i->txn_addr = txn_alloc_addr(irq);
65	i->txn_data = txn_alloc_data(irq);
66	i->irq = irq;
67
68	return irq;
69}
70
71EXPORT_SYMBOL(gsc_alloc_irq);
72EXPORT_SYMBOL(gsc_claim_irq);
73
74/* Common interrupt demultiplexer used by Asp, Lasi & Wax.  */
75irqreturn_t gsc_asic_intr(int gsc_asic_irq, void *dev)
76{
77	unsigned long irr;
78	struct gsc_asic *gsc_asic = dev;
79
80	irr = gsc_readl(gsc_asic->hpa + OFFSET_IRR);
81	if (irr == 0)
82		return IRQ_NONE;
83
84	DEBPRINTK("%s intr, mask=0x%x\n", gsc_asic->name, irr);
85
86	do {
87		int local_irq = __ffs(irr);
88		unsigned int irq = gsc_asic->global_irq[local_irq];
89		generic_handle_irq(irq);
90		irr &= ~(1 << local_irq);
91	} while (irr);
92
93	return IRQ_HANDLED;
94}
95
96int gsc_find_local_irq(unsigned int irq, int *global_irqs, int limit)
97{
98	int local_irq;
99
100	for (local_irq = 0; local_irq < limit; local_irq++) {
101		if (global_irqs[local_irq] == irq)
102			return local_irq;
103	}
104
105	return NO_IRQ;
106}
107
108static void gsc_asic_mask_irq(struct irq_data *d)
109{
110	struct gsc_asic *irq_dev = irq_data_get_irq_chip_data(d);
111	int local_irq = gsc_find_local_irq(d->irq, irq_dev->global_irq, 32);
112	u32 imr;
113
114	DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, d->irq,
115			irq_dev->name, imr);
116
117	/* Disable the IRQ line by clearing the bit in the IMR */
118	imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
119	imr &= ~(1 << local_irq);
120	gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
121}
122
123static void gsc_asic_unmask_irq(struct irq_data *d)
124{
125	struct gsc_asic *irq_dev = irq_data_get_irq_chip_data(d);
126	int local_irq = gsc_find_local_irq(d->irq, irq_dev->global_irq, 32);
127	u32 imr;
128
129	DEBPRINTK(KERN_DEBUG "%s(%d) %s: IMR 0x%x\n", __func__, d->irq,
130			irq_dev->name, imr);
131
132	/* Enable the IRQ line by setting the bit in the IMR */
133	imr = gsc_readl(irq_dev->hpa + OFFSET_IMR);
134	imr |= 1 << local_irq;
135	gsc_writel(imr, irq_dev->hpa + OFFSET_IMR);
136	/*
137	 * FIXME: read IPR to make sure the IRQ isn't already pending.
138	 *   If so, we need to read IRR and manually call do_irq().
139	 */
140}
141
142static struct irq_chip gsc_asic_interrupt_type = {
143	.name		=	"GSC-ASIC",
144	.irq_unmask	=	gsc_asic_unmask_irq,
145	.irq_mask	=	gsc_asic_mask_irq,
146};
147
148int gsc_assign_irq(struct irq_chip *type, void *data)
149{
150	static int irq = GSC_IRQ_BASE;
151
152	if (irq > GSC_IRQ_MAX)
153		return NO_IRQ;
154
155	irq_set_chip_and_handler(irq, type, handle_simple_irq);
156	irq_set_chip_data(irq, data);
157
158	return irq++;
159}
160
161void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp)
162{
163	int irq = asic->global_irq[local_irq];
164
165	if (irq <= 0) {
166		irq = gsc_assign_irq(&gsc_asic_interrupt_type, asic);
167		if (irq == NO_IRQ)
168			return;
169
170		asic->global_irq[local_irq] = irq;
171	}
172	*irqp = irq;
173}
174
175struct gsc_fixup_struct {
176	void (*choose_irq)(struct parisc_device *, void *);
177	void *ctrl;
178};
179
180static int gsc_fixup_irqs_callback(struct device *dev, void *data)
181{
182	struct parisc_device *padev = to_parisc_device(dev);
183	struct gsc_fixup_struct *gf = data;
184
185	/* work-around for 715/64 and others which have parent
186	   at path [5] and children at path [5/0/x] */
187	if (padev->id.hw_type == HPHW_FAULTY)
188		gsc_fixup_irqs(padev, gf->ctrl, gf->choose_irq);
189	gf->choose_irq(padev, gf->ctrl);
190
191	return 0;
192}
193
194void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl,
195			void (*choose_irq)(struct parisc_device *, void *))
196{
197	struct gsc_fixup_struct data = {
198		.choose_irq	= choose_irq,
199		.ctrl		= ctrl,
200	};
201
202	device_for_each_child(&parent->dev, &data, gsc_fixup_irqs_callback);
203}
204
205int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic)
206{
207	struct resource *res;
208	int i;
209
210	gsc_asic->gsc = parent;
211
212	/* Initialise local irq -> global irq mapping */
213	for (i = 0; i < 32; i++) {
214		gsc_asic->global_irq[i] = NO_IRQ;
215	}
216
217	/* allocate resource region */
218	res = request_mem_region(gsc_asic->hpa, 0x100000, gsc_asic->name);
219	if (res) {
220		res->flags = IORESOURCE_MEM; 	/* do not mark it busy ! */
221	}
222
223#if 0
224	printk(KERN_WARNING "%s IRQ %d EIM 0x%x", gsc_asic->name,
225			parent->irq, gsc_asic->eim);
226	if (gsc_readl(gsc_asic->hpa + OFFSET_IMR))
227		printk("  IMR is non-zero! (0x%x)",
228				gsc_readl(gsc_asic->hpa + OFFSET_IMR));
229	printk("\n");
230#endif
231
232	return 0;
233}
234
235extern struct parisc_driver lasi_driver;
236extern struct parisc_driver asp_driver;
237extern struct parisc_driver wax_driver;
238
239void __init gsc_init(void)
240{
241#ifdef CONFIG_GSC_LASI
242	register_parisc_driver(&lasi_driver);
243	register_parisc_driver(&asp_driver);
244#endif
245#ifdef CONFIG_GSC_WAX
246	register_parisc_driver(&wax_driver);
247#endif
248}
249