summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c
blob: 9d962d7c72c114c94403b971ef6c168e2097e152 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/*
 * PQ2 ADS-style PCI interrupt controller
 *
 * Copyright 2007 Freescale Semiconductor, Inc.
 * Author: Scott Wood <scottwood@freescale.com>
 *
 * Loosely based on mpc82xx ADS support by Vitaly Bordug <vbordug@ru.mvista.com>
 * Copyright (c) 2006 MontaVista Software, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <linux/bootmem.h>

#include <asm/io.h>
#include <asm/prom.h>
#include <asm/cpm2.h>

#include "pq2.h"

static DEFINE_SPINLOCK(pci_pic_lock);

struct pq2ads_pci_pic {
	struct device_node *node;
	struct irq_host *host;

	struct {
		u32 stat;
		u32 mask;
	} __iomem *regs;
};

#define NUM_IRQS 32

static void pq2ads_pci_mask_irq(unsigned int virq)
{
	struct pq2ads_pci_pic *priv = get_irq_chip_data(virq);
	int irq = NUM_IRQS - virq_to_hw(virq) - 1;

	if (irq != -1) {
		unsigned long flags;
		spin_lock_irqsave(&pci_pic_lock, flags);

		setbits32(&priv->regs->mask, 1 << irq);
		mb();

		spin_unlock_irqrestore(&pci_pic_lock, flags);
	}
}

static void pq2ads_pci_unmask_irq(unsigned int virq)
{
	struct pq2ads_pci_pic *priv = get_irq_chip_data(virq);
	int irq = NUM_IRQS - virq_to_hw(virq) - 1;

	if (irq != -1) {
		unsigned long flags;

		spin_lock_irqsave(&pci_pic_lock, flags);
		clrbits32(&priv->regs->mask, 1 << irq);
		spin_unlock_irqrestore(&pci_pic_lock, flags);
	}
}

static struct irq_chip pq2ads_pci_ic = {
	.name = "PQ2 ADS PCI",
	.end = pq2ads_pci_unmask_irq,
	.mask = pq2ads_pci_mask_irq,
	.mask_ack = pq2ads_pci_mask_irq,
	.ack = pq2ads_pci_mask_irq,
	.unmask = pq2ads_pci_unmask_irq,
	.enable = pq2ads_pci_unmask_irq,
	.disable = pq2ads_pci_mask_irq
};

static void pq2ads_pci_irq_demux(unsigned int irq, struct irq_desc *desc)
{
	struct pq2ads_pci_pic *priv = desc->handler_data;
	u32 stat, mask, pend;
	int bit;

	for (;;) {
		stat = in_be32(&priv->regs->stat);
		mask = in_be32(&priv->regs->mask);

		pend = stat & ~mask;

		if (!pend)
			break;

		for (bit = 0; pend != 0; ++bit, pend <<= 1) {
			if (pend & 0x80000000) {
				int virq = irq_linear_revmap(priv->host, bit);
				generic_handle_irq(virq);
			}
		}
	}
}

static int pci_pic_host_map(struct irq_host *h, unsigned int virq,
			    irq_hw_number_t hw)
{
	irq_to_desc(virq)->status |= IRQ_LEVEL;
	set_irq_chip_data(virq, h->host_data);
	set_irq_chip_and_handler(virq, &pq2ads_pci_ic, handle_level_irq);
	return 0;
}

static void pci_host_unmap(struct irq_host *h, unsigned int virq)
{
	/* remove chip and handler */
	set_irq_chip_data(virq, NULL);
	set_irq_chip(virq, NULL);
}

static struct irq_host_ops pci_pic_host_ops = {
	.map = pci_pic_host_map,
	.unmap = pci_host_unmap,
};

int __init pq2ads_pci_init_irq(void)
{
	struct pq2ads_pci_pic *priv;
	struct irq_host *host;
	struct device_node *np;
	int ret = -ENODEV;
	int irq;

	np = of_find_compatible_node(NULL, NULL, "fsl,pq2ads-pci-pic");
	if (!np) {
		printk(KERN_ERR "No pci pic node in device tree.\n");
		of_node_put(np);
		goto out;
	}

	irq = irq_of_parse_and_map(np, 0);
	if (irq == NO_IRQ) {
		printk(KERN_ERR "No interrupt in pci pic node.\n");
		of_node_put(np);
		goto out;
	}

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		of_node_put(np);
		ret = -ENOMEM;
		goto out_unmap_irq;
	}

	/* PCI interrupt controller registers: status and mask */
	priv->regs = of_iomap(np, 0);
	if (!priv->regs) {
		printk(KERN_ERR "Cannot map PCI PIC registers.\n");
		goto out_free_bootmem;
	}

	/* mask all PCI interrupts */
	out_be32(&priv->regs->mask, ~0);
	mb();

	host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, NUM_IRQS,
	                      &pci_pic_host_ops, NUM_IRQS);
	if (!host) {
		ret = -ENOMEM;
		goto out_unmap_regs;
	}

	host->host_data = priv;

	priv->host = host;
	host->host_data = priv;
	set_irq_data(irq, priv);
	set_irq_chained_handler(irq, pq2ads_pci_irq_demux);

	of_node_put(np);
	return 0;

out_unmap_regs:
	iounmap(priv->regs);
out_free_bootmem:
	free_bootmem((unsigned long)priv,
	             sizeof(struct pq2ads_pci_pic));
	of_node_put(np);
out_unmap_irq:
	irq_dispose_mapping(irq);
out:
	return ret;
}
OpenPOWER on IntegriCloud