summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
blob: 529897cef60c660f7a1c6cb461be024f4816847a (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
195
196
197
198
199
200
201
202
203
204
/*
 * Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Author: John Rigby, <jrigby@freescale.com>
 *
 * Description:
 * MPC5121ADS CPLD irq handling
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <asm/prom.h>

static struct device_node *cpld_pic_node;
static struct irq_host *cpld_pic_host;

/*
 * Bits to ignore in the misc_status register
 * 0x10 touch screen pendown is hard routed to irq1
 * 0x02 pci status is read from pci status register
 */
#define MISC_IGNORE 0x12

/*
 * Nothing to ignore in pci status register
 */
#define PCI_IGNORE 0x00

struct cpld_pic {
	u8 pci_mask;
	u8 pci_status;
	u8 route;
	u8 misc_mask;
	u8 misc_status;
	u8 misc_control;
};

static struct cpld_pic __iomem *cpld_regs;

static void __iomem *
irq_to_pic_mask(unsigned int irq)
{
	return irq <= 7 ? &cpld_regs->pci_mask : &cpld_regs->misc_mask;
}

static unsigned int
irq_to_pic_bit(unsigned int irq)
{
	return 1 << (irq & 0x7);
}

static void
cpld_mask_irq(struct irq_data *d)
{
	unsigned int cpld_irq = (unsigned int)irq_map[d->irq].hwirq;
	void __iomem *pic_mask = irq_to_pic_mask(cpld_irq);

	out_8(pic_mask,
	      in_8(pic_mask) | irq_to_pic_bit(cpld_irq));
}

static void
cpld_unmask_irq(struct irq_data *d)
{
	unsigned int cpld_irq = (unsigned int)irq_map[d->irq].hwirq;
	void __iomem *pic_mask = irq_to_pic_mask(cpld_irq);

	out_8(pic_mask,
	      in_8(pic_mask) & ~irq_to_pic_bit(cpld_irq));
}

static struct irq_chip cpld_pic = {
	.name = "CPLD PIC",
	.irq_mask = cpld_mask_irq,
	.irq_ack = cpld_mask_irq,
	.irq_unmask = cpld_unmask_irq,
};

static int
cpld_pic_get_irq(int offset, u8 ignore, u8 __iomem *statusp,
			    u8 __iomem *maskp)
{
	int cpld_irq;
	u8 status = in_8(statusp);
	u8 mask = in_8(maskp);

	/* ignore don't cares and masked irqs */
	status |= (ignore | mask);

	if (status == 0xff)
		return NO_IRQ_IGNORE;

	cpld_irq = ffz(status) + offset;

	return irq_linear_revmap(cpld_pic_host, cpld_irq);
}

static void
cpld_pic_cascade(unsigned int irq, struct irq_desc *desc)
{
	irq = cpld_pic_get_irq(0, PCI_IGNORE, &cpld_regs->pci_status,
		&cpld_regs->pci_mask);
	if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
		generic_handle_irq(irq);
		return;
	}

	irq = cpld_pic_get_irq(8, MISC_IGNORE, &cpld_regs->misc_status,
		&cpld_regs->misc_mask);
	if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
		generic_handle_irq(irq);
		return;
	}
}

static int
cpld_pic_host_match(struct irq_host *h, struct device_node *node)
{
	return cpld_pic_node == node;
}

static int
cpld_pic_host_map(struct irq_host *h, unsigned int virq,
			     irq_hw_number_t hw)
{
	irq_set_status_flags(virq, IRQ_LEVEL);
	set_irq_chip_and_handler(virq, &cpld_pic, handle_level_irq);
	return 0;
}

static struct
irq_host_ops cpld_pic_host_ops = {
	.match = cpld_pic_host_match,
	.map = cpld_pic_host_map,
};

void __init
mpc5121_ads_cpld_map(void)
{
	struct device_node *np = NULL;

	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic");
	if (!np) {
		printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n");
		return;
	}

	cpld_regs = of_iomap(np, 0);
	of_node_put(np);
}

void __init
mpc5121_ads_cpld_pic_init(void)
{
	unsigned int cascade_irq;
	struct device_node *np = NULL;

	pr_debug("cpld_ic_init\n");

	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic");
	if (!np) {
		printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n");
		return;
	}

	if (!cpld_regs)
		goto end;

	cascade_irq = irq_of_parse_and_map(np, 0);
	if (cascade_irq == NO_IRQ)
		goto end;

	/*
	 * statically route touch screen pendown through 1
	 * and ignore it here
	 * route all others through our cascade irq
	 */
	out_8(&cpld_regs->route, 0xfd);
	out_8(&cpld_regs->pci_mask, 0xff);
	/* unmask pci ints in misc mask */
	out_8(&cpld_regs->misc_mask, ~(MISC_IGNORE));

	cpld_pic_node = of_node_get(np);

	cpld_pic_host =
	    irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 16, &cpld_pic_host_ops, 16);
	if (!cpld_pic_host) {
		printk(KERN_ERR "CPLD PIC: failed to allocate irq host!\n");
		goto end;
	}

	set_irq_chained_handler(cascade_irq, cpld_pic_cascade);
end:
	of_node_put(np);
}