summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/sysdev/mpic_msgr.c
blob: 3f165d972a0eba6ef2eb6f1f7764d04e83e90c5d (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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
/*
 * Copyright 2011-2012, Meador Inge, Mentor Graphics Corporation.
 *
 * Some ideas based on un-pushed work done by Vivek Mahajan, Jason Jin, and
 * Mingkai Hu from Freescale Semiconductor, Inc.
 *
 * This program 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; version 2 of the
 * License.
 *
 */

#include <linux/list.h>
#include <linux/of_platform.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <asm/prom.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.h>
#include <asm/mpic_msgr.h>

#define MPIC_MSGR_REGISTERS_PER_BLOCK	4
#define MPIC_MSGR_STRIDE		0x10
#define MPIC_MSGR_MER_OFFSET		0x100
#define MSGR_INUSE			0
#define MSGR_FREE			1

static struct mpic_msgr **mpic_msgrs;
static unsigned int mpic_msgr_count;
static DEFINE_RAW_SPINLOCK(msgrs_lock);

static inline void _mpic_msgr_mer_write(struct mpic_msgr *msgr, u32 value)
{
	out_be32(msgr->mer, value);
}

static inline u32 _mpic_msgr_mer_read(struct mpic_msgr *msgr)
{
	return in_be32(msgr->mer);
}

static inline void _mpic_msgr_disable(struct mpic_msgr *msgr)
{
	u32 mer = _mpic_msgr_mer_read(msgr);

	_mpic_msgr_mer_write(msgr, mer & ~(1 << msgr->num));
}

struct mpic_msgr *mpic_msgr_get(unsigned int reg_num)
{
	unsigned long flags;
	struct mpic_msgr *msgr;

	/* Assume busy until proven otherwise.  */
	msgr = ERR_PTR(-EBUSY);

	if (reg_num >= mpic_msgr_count)
		return ERR_PTR(-ENODEV);

	raw_spin_lock_irqsave(&msgrs_lock, flags);
	msgr = mpic_msgrs[reg_num];
	if (msgr->in_use == MSGR_FREE)
		msgr->in_use = MSGR_INUSE;
	raw_spin_unlock_irqrestore(&msgrs_lock, flags);

	return msgr;
}
EXPORT_SYMBOL_GPL(mpic_msgr_get);

void mpic_msgr_put(struct mpic_msgr *msgr)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&msgr->lock, flags);
	msgr->in_use = MSGR_FREE;
	_mpic_msgr_disable(msgr);
	raw_spin_unlock_irqrestore(&msgr->lock, flags);
}
EXPORT_SYMBOL_GPL(mpic_msgr_put);

void mpic_msgr_enable(struct mpic_msgr *msgr)
{
	unsigned long flags;
	u32 mer;

	raw_spin_lock_irqsave(&msgr->lock, flags);
	mer = _mpic_msgr_mer_read(msgr);
	_mpic_msgr_mer_write(msgr, mer | (1 << msgr->num));
	raw_spin_unlock_irqrestore(&msgr->lock, flags);
}
EXPORT_SYMBOL_GPL(mpic_msgr_enable);

void mpic_msgr_disable(struct mpic_msgr *msgr)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&msgr->lock, flags);
	_mpic_msgr_disable(msgr);
	raw_spin_unlock_irqrestore(&msgr->lock, flags);
}
EXPORT_SYMBOL_GPL(mpic_msgr_disable);

/* The following three functions are used to compute the order and number of
 * the message register blocks.  They are clearly very inefficent.  However,
 * they are called *only* a few times during device initialization.
 */
static unsigned int mpic_msgr_number_of_blocks(void)
{
	unsigned int count;
	struct device_node *aliases;

	count = 0;
	aliases = of_find_node_by_name(NULL, "aliases");

	if (aliases) {
		char buf[32];

		for (;;) {
			snprintf(buf, sizeof(buf), "mpic-msgr-block%d", count);
			if (!of_find_property(aliases, buf, NULL))
				break;

			count += 1;
		}
	}

	return count;
}

static unsigned int mpic_msgr_number_of_registers(void)
{
	return mpic_msgr_number_of_blocks() * MPIC_MSGR_REGISTERS_PER_BLOCK;
}

static int mpic_msgr_block_number(struct device_node *node)
{
	struct device_node *aliases;
	unsigned int index, number_of_blocks;
	char buf[64];

	number_of_blocks = mpic_msgr_number_of_blocks();
	aliases = of_find_node_by_name(NULL, "aliases");
	if (!aliases)
		return -1;

	for (index = 0; index < number_of_blocks; ++index) {
		struct property *prop;

		snprintf(buf, sizeof(buf), "mpic-msgr-block%d", index);
		prop = of_find_property(aliases, buf, NULL);
		if (node == of_find_node_by_path(prop->value))
			break;
	}

	return index == number_of_blocks ? -1 : index;
}

/* The probe function for a single message register block.
 */
static int mpic_msgr_probe(struct platform_device *dev)
{
	void __iomem *msgr_block_addr;
	int block_number;
	struct resource rsrc;
	unsigned int i;
	unsigned int irq_index;
	struct device_node *np = dev->dev.of_node;
	unsigned int receive_mask;
	const unsigned int *prop;

	if (!np) {
		dev_err(&dev->dev, "Device OF-Node is NULL");
		return -EFAULT;
	}

	/* Allocate the message register array upon the first device
	 * registered.
	 */
	if (!mpic_msgrs) {
		mpic_msgr_count = mpic_msgr_number_of_registers();
		dev_info(&dev->dev, "Found %d message registers\n",
				mpic_msgr_count);

		mpic_msgrs = kcalloc(mpic_msgr_count, sizeof(*mpic_msgrs),
							 GFP_KERNEL);
		if (!mpic_msgrs) {
			dev_err(&dev->dev,
				"No memory for message register blocks\n");
			return -ENOMEM;
		}
	}
	dev_info(&dev->dev, "Of-device full name %s\n", np->full_name);

	/* IO map the message register block. */
	of_address_to_resource(np, 0, &rsrc);
	msgr_block_addr = ioremap(rsrc.start, rsrc.end - rsrc.start);
	if (!msgr_block_addr) {
		dev_err(&dev->dev, "Failed to iomap MPIC message registers");
		return -EFAULT;
	}

	/* Ensure the block has a defined order. */
	block_number = mpic_msgr_block_number(np);
	if (block_number < 0) {
		dev_err(&dev->dev,
			"Failed to find message register block alias\n");
		return -ENODEV;
	}
	dev_info(&dev->dev, "Setting up message register block %d\n",
			block_number);

	/* Grab the receive mask which specifies what registers can receive
	 * interrupts.
	 */
	prop = of_get_property(np, "mpic-msgr-receive-mask", NULL);
	receive_mask = (prop) ? *prop : 0xF;

	/* Build up the appropriate message register data structures. */
	for (i = 0, irq_index = 0; i < MPIC_MSGR_REGISTERS_PER_BLOCK; ++i) {
		struct mpic_msgr *msgr;
		unsigned int reg_number;

		msgr = kzalloc(sizeof(struct mpic_msgr), GFP_KERNEL);
		if (!msgr) {
			dev_err(&dev->dev, "No memory for message register\n");
			return -ENOMEM;
		}

		reg_number = block_number * MPIC_MSGR_REGISTERS_PER_BLOCK + i;
		msgr->base = msgr_block_addr + i * MPIC_MSGR_STRIDE;
		msgr->mer = (u32 *)((u8 *)msgr->base + MPIC_MSGR_MER_OFFSET);
		msgr->in_use = MSGR_FREE;
		msgr->num = i;
		raw_spin_lock_init(&msgr->lock);

		if (receive_mask & (1 << i)) {
			msgr->irq = irq_of_parse_and_map(np, irq_index);
			if (msgr->irq == NO_IRQ) {
				dev_err(&dev->dev,
						"Missing interrupt specifier");
				kfree(msgr);
				return -EFAULT;
			}
			irq_index += 1;
		} else {
			msgr->irq = NO_IRQ;
		}

		mpic_msgrs[reg_number] = msgr;
		mpic_msgr_disable(msgr);
		dev_info(&dev->dev, "Register %d initialized: irq %d\n",
				reg_number, msgr->irq);

	}

	return 0;
}

static const struct of_device_id mpic_msgr_ids[] = {
	{
		.compatible = "fsl,mpic-v3.1-msgr",
		.data = NULL,
	},
	{}
};

static struct platform_driver mpic_msgr_driver = {
	.driver = {
		.name = "mpic-msgr",
		.of_match_table = mpic_msgr_ids,
	},
	.probe = mpic_msgr_probe,
};

static __init int mpic_msgr_init(void)
{
	return platform_driver_register(&mpic_msgr_driver);
}
subsys_initcall(mpic_msgr_init);