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 
gsc_alloc_irq(struct gsc_irq * i)37 int 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 
gsc_claim_irq(struct gsc_irq * i,int irq)52 int 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 
71 EXPORT_SYMBOL(gsc_alloc_irq);
72 EXPORT_SYMBOL(gsc_claim_irq);
73 
74 /* Common interrupt demultiplexer used by Asp, Lasi & Wax.  */
gsc_asic_intr(int gsc_asic_irq,void * dev)75 irqreturn_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 
gsc_find_local_irq(unsigned int irq,int * global_irqs,int limit)96 int 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 
gsc_asic_mask_irq(struct irq_data * d)108 static 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 
gsc_asic_unmask_irq(struct irq_data * d)123 static 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 
142 #ifdef CONFIG_SMP
gsc_set_affinity_irq(struct irq_data * d,const struct cpumask * dest,bool force)143 static int gsc_set_affinity_irq(struct irq_data *d, const struct cpumask *dest,
144 				bool force)
145 {
146 	struct gsc_asic *gsc_dev = irq_data_get_irq_chip_data(d);
147 	struct cpumask tmask;
148 	int cpu_irq;
149 
150 	if (!cpumask_and(&tmask, dest, cpu_online_mask))
151 		return -EINVAL;
152 
153 	cpu_irq = cpu_check_affinity(d, &tmask);
154 	if (cpu_irq < 0)
155 		return cpu_irq;
156 
157 	gsc_dev->gsc_irq.txn_addr = txn_affinity_addr(d->irq, cpu_irq);
158 	gsc_dev->eim = ((u32) gsc_dev->gsc_irq.txn_addr) | gsc_dev->gsc_irq.txn_data;
159 
160 	/* switch IRQ's for devices below LASI/WAX to other CPU */
161 	gsc_writel(gsc_dev->eim, gsc_dev->hpa + OFFSET_IAR);
162 
163 	irq_data_update_effective_affinity(d, &tmask);
164 
165 	return IRQ_SET_MASK_OK;
166 }
167 #endif
168 
169 
170 static struct irq_chip gsc_asic_interrupt_type = {
171 	.name		=	"GSC-ASIC",
172 	.irq_unmask	=	gsc_asic_unmask_irq,
173 	.irq_mask	=	gsc_asic_mask_irq,
174 #ifdef CONFIG_SMP
175 	.irq_set_affinity =	gsc_set_affinity_irq,
176 #endif
177 };
178 
gsc_assign_irq(struct irq_chip * type,void * data)179 int gsc_assign_irq(struct irq_chip *type, void *data)
180 {
181 	static int irq = GSC_IRQ_BASE;
182 
183 	if (irq > GSC_IRQ_MAX)
184 		return NO_IRQ;
185 
186 	irq_set_chip_and_handler(irq, type, handle_simple_irq);
187 	irq_set_chip_data(irq, data);
188 
189 	return irq++;
190 }
191 
gsc_asic_assign_irq(struct gsc_asic * asic,int local_irq,int * irqp)192 void gsc_asic_assign_irq(struct gsc_asic *asic, int local_irq, int *irqp)
193 {
194 	int irq = asic->global_irq[local_irq];
195 
196 	if (irq <= 0) {
197 		irq = gsc_assign_irq(&gsc_asic_interrupt_type, asic);
198 		if (irq == NO_IRQ)
199 			return;
200 
201 		asic->global_irq[local_irq] = irq;
202 	}
203 	*irqp = irq;
204 }
205 
206 struct gsc_fixup_struct {
207 	void (*choose_irq)(struct parisc_device *, void *);
208 	void *ctrl;
209 };
210 
gsc_fixup_irqs_callback(struct device * dev,void * data)211 static int gsc_fixup_irqs_callback(struct device *dev, void *data)
212 {
213 	struct parisc_device *padev = to_parisc_device(dev);
214 	struct gsc_fixup_struct *gf = data;
215 
216 	/* work-around for 715/64 and others which have parent
217 	   at path [5] and children at path [5/0/x] */
218 	if (padev->id.hw_type == HPHW_FAULTY)
219 		gsc_fixup_irqs(padev, gf->ctrl, gf->choose_irq);
220 	gf->choose_irq(padev, gf->ctrl);
221 
222 	return 0;
223 }
224 
gsc_fixup_irqs(struct parisc_device * parent,void * ctrl,void (* choose_irq)(struct parisc_device *,void *))225 void gsc_fixup_irqs(struct parisc_device *parent, void *ctrl,
226 			void (*choose_irq)(struct parisc_device *, void *))
227 {
228 	struct gsc_fixup_struct data = {
229 		.choose_irq	= choose_irq,
230 		.ctrl		= ctrl,
231 	};
232 
233 	device_for_each_child(&parent->dev, &data, gsc_fixup_irqs_callback);
234 }
235 
gsc_common_setup(struct parisc_device * parent,struct gsc_asic * gsc_asic)236 int gsc_common_setup(struct parisc_device *parent, struct gsc_asic *gsc_asic)
237 {
238 	struct resource *res;
239 	int i;
240 
241 	gsc_asic->gsc = parent;
242 
243 	/* Initialise local irq -> global irq mapping */
244 	for (i = 0; i < 32; i++) {
245 		gsc_asic->global_irq[i] = NO_IRQ;
246 	}
247 
248 	/* allocate resource region */
249 	res = request_mem_region(gsc_asic->hpa, 0x100000, gsc_asic->name);
250 	if (res) {
251 		res->flags = IORESOURCE_MEM; 	/* do not mark it busy ! */
252 	}
253 
254 #if 0
255 	printk(KERN_WARNING "%s IRQ %d EIM 0x%x", gsc_asic->name,
256 			parent->irq, gsc_asic->eim);
257 	if (gsc_readl(gsc_asic->hpa + OFFSET_IMR))
258 		printk("  IMR is non-zero! (0x%x)",
259 				gsc_readl(gsc_asic->hpa + OFFSET_IMR));
260 	printk("\n");
261 #endif
262 
263 	return 0;
264 }
265 
266 extern struct parisc_driver lasi_driver;
267 extern struct parisc_driver asp_driver;
268 extern struct parisc_driver wax_driver;
269 
gsc_init(void)270 void __init gsc_init(void)
271 {
272 #ifdef CONFIG_GSC_LASI
273 	register_parisc_driver(&lasi_driver);
274 	register_parisc_driver(&asp_driver);
275 #endif
276 #ifdef CONFIG_GSC_WAX
277 	register_parisc_driver(&wax_driver);
278 #endif
279 }
280